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Piro A, Luo Y, Zhang Z, Ye W, Kang F, Li X, Wang Y, Dai FF, Gaisano HY, Rocheleau JV, Prentice KJ, Wheeler MB. Beta cell specific ZnT8 gene deficiency and resulting loss in zinc content significantly improve insulin secretion. Mol Cell Endocrinol 2024:112376. [PMID: 39321953 DOI: 10.1016/j.mce.2024.112376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 09/06/2024] [Accepted: 09/22/2024] [Indexed: 09/27/2024]
Abstract
Zinc transporter 8 (ZnT8) is highly expressed in pancreatic beta cells, localizes to insulin secretory granules (ISG), and regulates zinc content. ZnT8 gene polymorphisms have revealed a relationship between ZnT8 activity and type 2 diabetes (T2D) risk, however, the role of beta-cell ZnT8 is not well understood. A beta cell specific ZnT8 knockout (ZnT8 BKO) mouse model was investigated. ZnT8 BKO islets showed significantly reduced ZnT8 gene expression and reduced zinc content. In vivo, ZnT8 BKO mice compared to controls displayed significantly elevated plasma insulin levels and improved glucose tolerance following acute insulin resistance induced via S961. Glucose stimulated insulin secretion from isolated ZnT8 BKO pancreatic islets revealed enhanced insulin secretion capacity. The difference in insulin secretion between ZnT8 BKO and control islets was negated upon zinc supplementation, and the inhibitory effect was confirmed in human islets. These results indicate that the loss of ZnT8 activity, and accompanying reduced cellular zinc are associated with increased insulin secretion capacity. The reduction in secreted insulin content upon zinc supplementation in ZnT8 BKO islets suggests that ISG-released zinc normally tempers insulin secretion.
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Affiliation(s)
- Anthony Piro
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Yihan Luo
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ziyi Zhang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wenyue Ye
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Fei Kang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Xie Li
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Yufeng Wang
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Feihan F Dai
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Herbert Y Gaisano
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Jonathan V Rocheleau
- Department of Endocrinology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang, China; Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada
| | - Kacey J Prentice
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Michael B Wheeler
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Yuan YC, Wang H, Jiang ZJ, Liu C, Li Q, Zhou SR, Yang JK. Potassium voltage-gated channel subfamily H member 2 (KCNH2) is a promising target for incretin secretagogue therapies. Signal Transduct Target Ther 2024; 9:207. [PMID: 39128897 PMCID: PMC11317495 DOI: 10.1038/s41392-024-01923-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 06/16/2024] [Accepted: 07/14/2024] [Indexed: 08/13/2024] Open
Abstract
Derived from enteroendocrine cells (EECs), glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) are pivotal incretin hormones crucial for blood glucose regulation. Medications of GLP-1 analogs and GLP-1 receptor activators are extensively used in the treatment of type 2 diabetes (T2D) and obesity. However, there are currently no agents to stimulate endogenous incretin secretion. Here, we find the pivotal role of KCNH2 potassium channels in the regulation of incretin secretion. Co-localization of KCNH2 with incretin-secreting EECs in the intestinal epithelium of rodents highlights its significance. Gut epithelial cell-specific KCNH2 knockout in mice improves glucose tolerance and increases oral glucose-triggered GLP-1 and GIP secretion, particularly GIP. Furthermore, KCNH2-deficient primary intestinal epithelial cells exhibit heightened incretin, especially GIP secretion upon nutrient stimulation. Mechanistically, KCNH2 knockdown in EECs leads to reduced K+ currents, prolonged action potential duration, and elevated intracellular calcium levels. Finally, we found that dofetilide, a KCNH2-specific inhibitor, could promote incretin secretion in enteroendocrine STC-1 cells in vitro and in hyperglycemic mice in vivo. These findings elucidate, for the first time, the mechanism and application of KCNH2 in regulating incretin secretion by EECs. Given the therapeutic promise of GLP-1 and GIP in diabetes and obesity management, this study advances our understanding of incretin regulation, paving the way for potential incretin secretagogue therapies in the treatment of diabetes and obesity.
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Affiliation(s)
- Ying-Chao Yuan
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China
| | - Hao Wang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China.
| | - Ze-Ju Jiang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China
| | - Chang Liu
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Qi Li
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China
| | - Si-Rui Zhou
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China
| | - Jin-Kui Yang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China.
- Subcenter of State Key Laboratory of Kidney Disease, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
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Jaffredo M, Krentz NA, Champon B, Duff CE, Nawaz S, Beer N, Honore C, Clark A, Rorsman P, Lang J, Gloyn AL, Raoux M, Hastoy B. Electrophysiological Characterization of Inducible Pluripotent Stem Cell-Derived Human β-Like Cells and an SLC30A8 Disease Model. Diabetes 2024; 73:1255-1265. [PMID: 38985991 PMCID: PMC11262041 DOI: 10.2337/db23-0776] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 05/05/2024] [Indexed: 07/12/2024]
Abstract
Inducible pluripotent stem cell-derived human β-like cells (BLCs) hold promise for both therapy and disease modeling, but their generation remains challenging and their functional analyses beyond transcriptomic and morphological assessments remain limited. Here, we validate an approach using multicellular and single-cell electrophysiological tools to evaluate function of BLCs from pioneer protocols that can be easily adapted to more differentiated BLCs. The multi-electrode arrays (MEAs) measuring the extracellular electrical activity revealed that BLCs, like primary β-cells, are electrically coupled and produce slow potential (SP) signals that are closely linked to insulin secretion. We also used high-resolution single-cell patch clamp measurements to capture the exocytotic properties, and characterize voltage-gated sodium and calcium currents, and found that they were comparable with those in primary β- and EndoC-βH1 cells. The KATP channel conductance is greater than in human primary β-cells, which may account for the limited glucose responsiveness observed with MEA. We used MEAs to study the impact of the type 2 diabetes-protective SLC30A8 allele (p.Lys34Serfs50*) and found that BLCs with this allele have stronger electrical coupling activity. Our data suggest that BLCs can be used to evaluate the functional impact of genetic variants on β-cell function and coupling. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Manon Jaffredo
- University of Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac, France
| | - Nicole A.J. Krentz
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
- Department of Pediatrics, Stanford School of Medicine, Stanford University, Stanford, CA
| | - Benoite Champon
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | - Claire E. Duff
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | - Sameena Nawaz
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
- King Abdulaziz University and University of Oxford Centre for Artificial Intelligence in Precision Medicine (KO-CAIPM), University of Oxford, Oxford, U.K
| | - Nicola Beer
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | | | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | - Jochen Lang
- University of Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac, France
| | - Anna L. Gloyn
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
- Department of Pediatrics, Stanford School of Medicine, Stanford University, Stanford, CA
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
| | - Matthieu Raoux
- University of Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac, France
| | - Benoit Hastoy
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, U.K
- King Abdulaziz University and University of Oxford Centre for Artificial Intelligence in Precision Medicine (KO-CAIPM), University of Oxford, Oxford, U.K
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4
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Kato Y, Ariyoshi K, Nohara Y, Matsunaga N, Shimauchi T, Shindo N, Nishimura A, Mi X, Kim SG, Ide T, Kawanishi E, Ojida A, Nakashima N, Mori Y, Nishida M. Inhibition of dynamin-related protein 1-filamin interaction improves systemic glucose metabolism. Br J Pharmacol 2024. [PMID: 38986570 DOI: 10.1111/bph.16487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 05/05/2024] [Accepted: 05/18/2024] [Indexed: 07/12/2024] Open
Abstract
BACKGROUND AND PURPOSE Maintaining mitochondrial quality is attracting attention as a new strategy to treat diabetes and diabetic complications. We previously reported that mitochondrial hyperfission by forming a protein complex between dynamin-related protein (Drp) 1 and filamin, mediates chronic heart failure and cilnidipine, initially developed as an L/N-type Ca2+ channel blocker, improves heart failure by inhibiting Drp1-filamin protein complex. We investigated whether cilnidipine improves hyperglycaemia of various diabetic mice models. EXPERIMENTAL APPROACH Retrospective analysis focusing on haemoglobin A1c (HbA1c) was performed in hypertensive and hyperglycaemic patients taking cilnidipine and amlodipine. After developing diabetic mice by streptozotocin (STZ) treatment, an osmotic pump including drug was implanted intraperitoneally, followed by weekly measurements of blood glucose levels. Mitochondrial morphology was analysed by electron microscopy. A Ca2+ channel-insensitive cilnidipine derivative (1,4-dihydropyridine [DHP]) was synthesized and its pharmacological effect was evaluated using obese (ob/ob) mice fed with high-fat diet (HFD). KEY RESULTS In patients, cilnidipine was superior to amlodipine in HbA1c lowering effect. Cilnidipine treatment improved systemic hyperglycaemia and mitochondrial morphological abnormalities in STZ-exposed mice, without lowering blood pressure. Cilnidipine failed to improve hyperglycaemia of ob/ob mice, with suppressing insulin secretion. 1,4-DHP improved hyperglycaemia and mitochondria abnormality in ob/ob mice fed HFD. 1,4-DHP and cilnidipine improved basal oxygen consumption rate of HepG2 cells cultured under 25 mM glucose. CONCLUSION AND IMPLICATIONS Inhibition of Drp1-filamin protein complex formation becomes a new strategy for type 2 diabetes treatment.
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Affiliation(s)
- Yuri Kato
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Kohei Ariyoshi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasunobu Nohara
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto, Japan
| | - Naoya Matsunaga
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Tsukasa Shimauchi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
| | - Naoya Shindo
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Akiyuki Nishimura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
| | - Xinya Mi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Sang Geon Kim
- College of Pharmacy, Dongguk University-Seoul, Goyang-si, South Korea
| | - Tomomi Ide
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Eiji Kawanishi
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Akio Ojida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Naoki Nakashima
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasuo Mori
- Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Motohiro Nishida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi, Japan
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5
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Chbel A, Lafnoune A, Nait Irahal I, Bourhim N. Macromolecules from mushrooms, venoms, microorganisms, and plants for diabetes treatment - Progress or setback? Biochimie 2024:S0300-9084(24)00163-9. [PMID: 38996998 DOI: 10.1016/j.biochi.2024.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 06/13/2024] [Accepted: 07/09/2024] [Indexed: 07/14/2024]
Abstract
Diabetes is a substantial public health issue, while its prevalence continues to rise worldwide, affecting millions of persons between the ages of 20 and 80, the development of new therapeutic classes improving glycemic control and consequently micro and macrovascular complications are needed. Today, diabetes treatment is daily for life, and should not be interrupted. However, insulin secretagogues medications, and exogenous self-administration of insulin provide efficient antidiabetic effects, but their misuse leads to hypoglycemic complications besides other risks, hence the need to look for other natural products not to use solely but in concert with others types of medications. In this review, we will highlight briefly the pathophysiology of diabetes and its complications, then we will report the main bioactive macromolecules derived from various sources of natural products providing anti-diabetic properties. However, further researches need to be carried out to face the limitations hampering the development of effective natural drugs for diabetes treatment.
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Affiliation(s)
- Asmaa Chbel
- Faculté Des Sciences Ain Chock, Université Hassan II de Casablanca, BP5366 Maarif, Casablanca, Morocco
| | - Ayoub Lafnoune
- Laboratoire des Venins et Toxines, Département de Recherche, Institut Pasteur Du Maroc, 1, Place Louis Pasteur, Casablanca, 20360, Morocco
| | - Imane Nait Irahal
- Laboratoire Santé Et Environnement, Faculté Des Sciences Ain Chock, Université Hassan II de Casablanca, BP5366 Maarif, Casablanca, Morocco; INSERM U1197, Hôpital Paul Brousse, Bâtiment Lavoisier, 94807, Villejuif Cedex, France.
| | - Noureddine Bourhim
- Laboratoire Santé Et Environnement, Faculté Des Sciences Ain Chock, Université Hassan II de Casablanca, BP5366 Maarif, Casablanca, Morocco
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Suckert C, Zosel C, Schaefer M. Simultaneous TIRF imaging of subplasmalemmal Ca 2+ dynamics and granule fusions in insulin-secreting INS-1 cells reveals coexistent synchronized and asynchronous release. Cell Calcium 2024; 120:102883. [PMID: 38643716 DOI: 10.1016/j.ceca.2024.102883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/21/2024] [Accepted: 03/29/2024] [Indexed: 04/23/2024]
Abstract
The basal and glucose-induced insulin secretion from pancreatic beta cells is a tightly regulated process that is triggered in a Ca2+-dependent fashion and further positively modulated by substances that raise intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or by certain antidiabetic drugs. In a previous study, we have temporally resolved the subplasmalemmal [Ca2+]i dynamics in beta cells that are characterized by trains of sharply delimited spikes, reaching peak values up to 5 µM. Applying total internal reflection fluorescence (TIRF) microscopy and synaptopHluorin to visualize fusion events of individual granules, we found that several fusion events can coincide within 50 to 150 ms. To test whether subplasmalemmal [Ca2+]i microdomains around single or clustered Ca2+ channels may cause a synchronized release of insulin-containing vesicles, we applied simultaneous dual-color TIRF microscopy and monitored Ca2+ fluctuations and exocytotic events in INS-1 cells at high frame rates. The results indicate that fusions can be triggered by subplasmalemmal Ca2+ spiking. This, however, does account for a minority of fusion events. About 90 %-95 % of fusion events either happen between Ca2+ spikes or incidentally overlap with subplasmalemmal Ca2+ spikes. We conclude that only a fraction of exocytotic events in glucose-induced and tolbutamide- or forskolin-enhanced insulin release from INS-1 cells is tightly coupled to Ca2+ microdomains around voltage-gated Ca2+ channels.
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Affiliation(s)
- Charlotte Suckert
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Carolin Zosel
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany
| | - Michael Schaefer
- Leipzig University, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Härtelstraße 16-18, Leipzig 04107, Germany.
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7
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Murao N, Morikawa R, Seino Y, Shimomura K, Maejima Y, Yamada Y, Suzuki A. Sildenafil amplifies calcium influx and insulin secretion in pancreatic β cells. Physiol Rep 2024; 12:e16091. [PMID: 38862270 PMCID: PMC11166479 DOI: 10.14814/phy2.16091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/13/2024] Open
Abstract
Sildenafil, a phosphodiesterase-5 (PDE5) inhibitor, has been shown to improve insulin sensitivity in animal models and prediabetic patients. However, its other metabolic effects remain poorly investigated. This study examines the impact of sildenafil on insulin secretion in MIN6-K8 mouse clonal β cells. Sildenafil amplified insulin secretion by enhancing Ca2+ influx. These effects required other depolarizing stimuli in MIN6-K8 cells but not in KATP channel-deficient β cells, which were already depolarized, indicating that sildenafil-amplified insulin secretion is depolarization-dependent and KATP channel-independent. Interestingly, sildenafil-amplified insulin secretion was inhibited by pharmacological inhibition of R-type channels, but not of other types of voltage-dependent Ca2+ channels (VDCCs). Furthermore, sildenafil-amplified insulin secretion was barely affected when its effect on cyclic GMP was inhibited by PDE5 knockdown. Thus, sildenafil stimulates insulin secretion and Ca2+ influx through R-type VDCCs independently of the PDE5/cGMP pathway, a mechanism that differs from the known pharmacology of sildenafil and conventional insulin secretory pathways. Our results reposition sildenafil as an insulinotropic agent that can be used as a potential antidiabetic medicine and a tool to elucidate the novel mechanism of insulin secretion.
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Affiliation(s)
- Naoya Murao
- Department of Endocrinology, Diabetes and MetabolismSchool of Medicine, Fujita Health UniversityToyoakeJapan
- Yutaka Seino Distinguished Center for Diabetes ResearchKansai Electric Power Medical Research InstituteKyotoJapan
| | - Risa Morikawa
- Department of Endocrinology, Diabetes and MetabolismSchool of Medicine, Fujita Health UniversityToyoakeJapan
| | - Yusuke Seino
- Department of Endocrinology, Diabetes and MetabolismSchool of Medicine, Fujita Health UniversityToyoakeJapan
- Yutaka Seino Distinguished Center for Diabetes ResearchKansai Electric Power Medical Research InstituteKyotoJapan
| | - Kenju Shimomura
- Department of Bioregulation and Pharmacological MedicineSchool of Medicine, Fukushima Medical UniversityFukushimaJapan
| | - Yuko Maejima
- Department of Bioregulation and Pharmacological MedicineSchool of Medicine, Fukushima Medical UniversityFukushimaJapan
| | - Yuichiro Yamada
- Department of Endocrinology, Diabetes and MetabolismSchool of Medicine, Fujita Health UniversityToyoakeJapan
- Yutaka Seino Distinguished Center for Diabetes ResearchKansai Electric Power Medical Research InstituteKyotoJapan
| | - Atsushi Suzuki
- Department of Endocrinology, Diabetes and MetabolismSchool of Medicine, Fujita Health UniversityToyoakeJapan
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8
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Yau B, Madsen S, Nelson ME, Cooke KC, Fritzen AM, Thorius IH, Stöckli J, James DE, Kebede MA. Genetics and diet shape the relationship between islet function and whole body metabolism. Am J Physiol Endocrinol Metab 2024; 326:E663-E672. [PMID: 38568150 PMCID: PMC11376487 DOI: 10.1152/ajpendo.00060.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 05/08/2024]
Abstract
Despite the fact that genes and the environment are known to play a central role in islet function, our knowledge of how these parameters interact to modulate insulin secretory function remains relatively poor. Presently, we performed ex vivo glucose-stimulated insulin secretion and insulin content assays in islets of 213 mice from 13 inbred mouse strains on chow, Western diet (WD), and a high-fat, carbohydrate-free (KETO) diet. Strikingly, among these 13 strains, islets from the commonly used C57BL/6J mouse strain were the least glucose responsive. Using matched metabolic phenotyping data, we performed correlation analyses of isolated islet parameters and found a positive correlation between basal and glucose-stimulated insulin secretion, but no relationship between insulin secretion and insulin content. Using in vivo metabolic measures, we found that glucose tolerance determines the relationship between ex vivo islet insulin secretion and plasma insulin levels. Finally, we showed that islet glucose-stimulated insulin secretion decreased with KETO in almost all strains, concomitant with broader phenotypic changes, such as increased adiposity and glucose intolerance. This is an important finding as it should caution against the application of KETO diet for beta-cell health. Together these data offer key insights into the intersection of diet and genetic background on islet function and whole body glucose metabolism.NEW & NOTEWORTHY Thirteen strains of mice on chow, Western diet, and high-fat, carbohydrate-free (KETO), correlating whole body phenotypes to ex vivo pancreatic islet functional measurements, were used. The study finds a huge spectrum of functional islet responses and insulin phenotypes across all strains and diets, with the ubiquitous C57Bl/6J mouse exhibiting the lowest secretory response of all strains, highlighting the overall importance of considering genetic background when investigating islet function. Ex vivo basal and stimulated insulin secretion are correlated in the islet, and KETO imparts widescale downregulation of islet insulin secretion.
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Affiliation(s)
- Belinda Yau
- School of Medical Science, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Søren Madsen
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Marin E Nelson
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Kristen C Cooke
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Andreas M Fritzen
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Ida H Thorius
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Jacqueline Stöckli
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - David E James
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
| | - Melkam A Kebede
- School of Medical Science, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
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9
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Xiong FR, Lu J, Zhu JJ, Zhao RX, Zhang YC, Yang JK. KCNH6 is essential for insulin secretion by regulating intracellular ER Ca 2+ store. FASEB J 2024; 38:e23490. [PMID: 38363581 DOI: 10.1096/fj.202302194rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/17/2024] [Accepted: 01/30/2024] [Indexed: 02/17/2024]
Abstract
Appropriate Ca2+ concentration in the endoplasmic reticulum (ER), modulating cytosolic Ca2+ signal, serves significant roles in physiological function of pancreatic β cells. To maintaining ER homeostasis, Ca2+ movement across the ER membrane is always accompanied by a simultaneous K+ flux in the opposite direction. KCNH6 was proven to modulate insulin secretion by controlling plasma membrane action potential duration and intracellular Ca2+ influx. Meanwhile, the specific function of KCNH6 in pancreatic β-cells remains unclear. In this study, we found that KCNH6 exhibited mainly ER localization and Kcnh6 β-cell-specific knockout (βKO) mice suffered from abnormal glucose tolerance and impaired insulin secretion in adulthood. ER Ca2+ store was overloaded in islets of βKO mice, which contributed to ER stress and ER stress-induced apoptosis in β cells. Next, we verified that ethanol treatment induced increases in ER Ca2+ store and apoptosis in pancreatic β cells, whereas adenovirus-mediated KCNH6 overexpression in islets attenuated ethanol-induced ER stress and apoptosis. In addition, tail-vein injections of KCNH6 lentivirus rescued KCNH6 expression in βKO mice, restored ER Ca2+ overload and attenuated ER stress in β cells, which further confirms that KCNH6 protects islets from ER stress and apoptosis. These data suggest that KCNH6 on the ER membrane may help to stabilize intracellular ER Ca2+ stores and protect β cells from ER stress and apoptosis. In conclusion, our study reveals the protective potential of KCNH6-targeting drugs in ER stress-induced diabetes.
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Affiliation(s)
- Feng-Ran Xiong
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
| | - Jing Lu
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
| | - Juan-Juan Zhu
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
| | - Ru-Xuan Zhao
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
| | - Ying-Chao Zhang
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
| | - Jin-Kui Yang
- Department of Endocrinology, Beijing Diabetes Institute, Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China
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10
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Wang H, Li Q, Yuan YC, Han XC, Cao YT, Yang JK. KCNH6 channel promotes insulin exocytosis via interaction with Munc18-1 independent of electrophysiological processes. Cell Mol Life Sci 2024; 81:86. [PMID: 38349432 PMCID: PMC10864572 DOI: 10.1007/s00018-024-05134-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/23/2023] [Accepted: 01/19/2024] [Indexed: 02/15/2024]
Abstract
Glucose-stimulated insulin secretion (GSIS) in pancreatic islet β-cells primarily relies on electrophysiological processes. Previous research highlighted the regulatory role of KCNH6, a member of the Kv channel family, in governing GSIS through its influence on β-cell electrophysiology. In this study, we unveil a novel facet of KCNH6's function concerning insulin granule exocytosis, independent of its conventional electrical role. Young mice with β-cell-specific KCNH6 knockout (βKO) exhibited impaired glucose tolerance and reduced insulin secretion, a phenomenon not explained by electrophysiological processes alone. Consistently, islets from KCNH6-βKO mice exhibited reduced insulin secretion, conversely, the overexpression of KCNH6 in murine pancreatic islets significantly enhanced insulin release. Moreover, insulin granules lacking KCNH6 demonstrated compromised docking capabilities and a reduced fusion response upon glucose stimulation. Crucially, our investigation unveiled a significant interaction between KCNH6 and the SNARE protein regulator, Munc18-1, a key mediator of insulin granule exocytosis. These findings underscore the critical role of KCNH6 in the regulation of insulin secretion through its interaction with Munc18-1, providing a promising and novel avenue for enhancing our understanding of the Kv channel in diabetes mechanisms.
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Affiliation(s)
- Hao Wang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China.
| | - Qi Li
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China
| | - Ying-Chao Yuan
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Xue-Chun Han
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Yong-Ting Cao
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Department of Endocrinology, Beijing Mentougou District Hospital, Beijing, 102399, China
| | - Jin-Kui Yang
- Beijing Key Laboratory of Diabetes Research and Care, Department of Endocrinology and Metabolism, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, 100069, China.
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11
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Vaishali, Adlakha N. Model of Calcium Dynamics Regulating [Formula: see text], ATP and Insulin Production in a Pancreatic [Formula: see text]-Cell. Acta Biotheor 2024; 72:2. [PMID: 38334878 DOI: 10.1007/s10441-024-09477-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 12/30/2023] [Indexed: 02/10/2024]
Abstract
The calcium signals regulate the production and secretion of many signaling molecules like inositol trisphosphate ([Formula: see text]) and adenosine triphosphate (ATP) in various cells including pancreatic [Formula: see text]-cells. The calcium signaling mechanisms regulating [Formula: see text], ATP and insulin responsible for various functions of [Formula: see text]-cells are still not well understood. Any disturbance in these mechanisms can alter the functions of [Formula: see text]-cells leading to diabetes and metabolic disorders. Therefore, a mathematical model is proposed by incorporating the reaction-diffusion equation for calcium dynamics and a system of first-order differential equations for [Formula: see text], ATP-production and insulin secretion with initial and boundary conditions. The model incorporates the temporal dependence of [Formula: see text]-production and degradation, ATP production and insulin secretion on calcium dynamics in a [Formula: see text]-cell. The piecewise linear finite element method has been used for the spatial dimension and the Crank-Nicolson scheme for the temporal dimension to obtain numerical results. The effect of changes in source influxes and buffers on calcium dynamics and production of [Formula: see text], ATP and insulin levels in a [Formula: see text]-cell has been analyzed. It is concluded that the dysfunction of source influx and buffers can cause significant variations in calcium levels and dysregulation of [Formula: see text], ATP and insulin production, which can lead to various metabolic disorders, diabetes, obesity, etc. The proposed model provides crucial information about the changes in mechanisms of calcium dynamics causing proportionate disturbances in [Formula: see text], ATP and insulin levels in pancreatic cells, which can be helpful for devising protocols for diagnosis and treatment of various metabolic diseases.
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Affiliation(s)
- Vaishali
- Department of Mathematics, SVNIT, Surat, Gujarat, 395007, India.
| | - Neeru Adlakha
- Department of Mathematics, SVNIT, Surat, Gujarat, 395007, India
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12
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Félix-Martínez GJ, Godínez-Fernández JR. A primer on modelling pancreatic islets: from models of coupled β-cells to multicellular islet models. Islets 2023; 15:2231609. [PMID: 37415423 PMCID: PMC10332213 DOI: 10.1080/19382014.2023.2231609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/27/2023] [Indexed: 07/08/2023] Open
Abstract
Pancreatic islets are mini-organs composed of hundreds or thousands of ɑ, β and δ-cells, which, respectively, secrete glucagon, insulin and somatostatin, key hormones for the regulation of blood glucose. In pancreatic islets, hormone secretion is tightly regulated by both internal and external mechanisms, including electrical communication and paracrine signaling between islet cells. Given its complexity, the experimental study of pancreatic islets has been complemented with computational modeling as a tool to gain a better understanding about how all the mechanisms involved at different levels of organization interact. In this review, we describe how multicellular models of pancreatic cells have evolved from the early models of electrically coupled β-cells to models in which experimentally derived architectures and both electrical and paracrine signals have been considered.
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Affiliation(s)
- Gerardo J. Félix-Martínez
- Investigador por México CONAHCYT-Department of Electrical Engineering, Universidad Autónoma Metropolitana, Mexico, Mexico
- Department of Electrical Engineering, Universidad Autónoma Metropolitana, Mexico, Mexico
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13
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Adamson SE, Li ZA, Hughes JW. Beta cell primary cilia mediate somatostatin responsiveness via SSTR3. Islets 2023; 15:2252855. [PMID: 37660302 PMCID: PMC10478741 DOI: 10.1080/19382014.2023.2252855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023] Open
Abstract
Somatostatin is a paracrine modulator of insulin secretion and beta cell function with pleotropic effects on glucose homeostasis. The mechanism of somatostatin-mediated communication between delta and beta cells is not well-understood, which we address in this study via the ciliary somatostatin receptor 3 (SSTR3). Primary cilia are membrane organelles that act as signaling hubs in islets by virtue of their subcellular location and enrichment in signaling proteins such as G-protein coupled receptors (GPCRs). We show that SSTR3, a ciliary GPCR, mediates somatostatin suppression of insulin secretion in mouse islets. Quantitative analysis of calcium flux using a mouse model of genetically encoded beta cell-specific GCaMP6f calcium reporter shows that somatostatin signaling alters beta cell calcium flux after physiologic glucose stimulation, an effect that depends on endogenous SSTR3 expression and the presence of intact primary cilia on beta cells. Comparative in vitro studies using SSTR isoform antagonists demonstrate a role for SSTR3 in mediating somatostatin regulation of insulin secretion in mouse islets. Our findings support a model in which ciliary SSTR3 mediates a distinct pathway of delta-to-beta cell regulatory crosstalk and may serve as a target for paracrine modulation.
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Affiliation(s)
- Samantha E. Adamson
- Department of Medicine, Division of Endocrinology, Metabolism & Lipid Research, Washington University School of Medicine, St. Louis, USA
| | - Zipeng A. Li
- Department of Medicine, Division of Endocrinology, Metabolism & Lipid Research, Washington University School of Medicine, St. Louis, USA
| | - Jing W. Hughes
- Department of Medicine, Division of Endocrinology, Metabolism & Lipid Research, Washington University School of Medicine, St. Louis, USA
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14
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Khin PP, Lee JH, Jun HS. Pancreatic Beta-cell Dysfunction in Type 2 Diabetes. EUR J INFLAMM 2023. [DOI: 10.1177/1721727x231154152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pancreatic β-cells produce and secrete insulin to maintain blood glucose levels within a narrow range. Defects in the function and mass of β-cells play a significant role in the development and progression of diabetes. Increased β-cell deficiency and β-cell apoptosis are observed in the pancreatic islets of patients with type 2 diabetes. At an early stage, β-cells adapt to insulin resistance, and their insulin secretion increases, but they eventually become exhausted, and the β-cell mass decreases. Various causal factors, such as high glucose, free fatty acids, inflammatory cytokines, and islet amyloid polypeptides, contribute to the impairment of β-cell function. Therefore, the maintenance of β-cell function is a logical approach for the treatment and prevention of diabetes. In this review, we provide an overview of the role of these risk factors in pancreatic β-cell loss and the associated mechanisms. A better understanding of the molecular mechanisms underlying pancreatic β-cell loss will provide an opportunity to identify novel therapeutic targets for type 2 diabetes.
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Affiliation(s)
- Phyu Phyu Khin
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 155, Gaetbeol-ro, Yeonsu-gu, Incheon 21999, Republic of Korea
| | - Jong Han Lee
- Department of Marine Bio-industry, Hanseo University, Seosan, Korea
| | - Hee-Sook Jun
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, 155, Gaetbeol-ro, Yeonsu-gu, Incheon 21999, Republic of Korea
- College of Pharmacy and Gachon Institute of Pharmaceutical Science, Gachon University, 191, Hambangmoe-ro, Yeonsu-gu, Incheon 21936, Republic of Korea
- Gachon Medical Research Institute, Gil Hospital, 21, Namdong-daero 774, beon-gil, Namdong-gu, Incheon, 21565, Republic of Korea
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15
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George LF, Follmer ML, Fontenoy E, Moran HR, Brown JR, Ozekin YH, Bates EA. Endoplasmic Reticulum Calcium Mediates Drosophila Wing Development. Bioelectricity 2023; 5:290-306. [PMID: 38143873 PMCID: PMC10733776 DOI: 10.1089/bioe.2022.0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023] Open
Abstract
Background The temporal dynamics of morphogen presentation impacts transcriptional responses and tissue patterning. However, the mechanisms controlling morphogen release are far from clear. We found that inwardly rectifying potassium (Irk) channels regulate endogenous transient increases in intracellular calcium and bone morphogenetic protein (BMP/Dpp) release for Drosophila wing development. Inhibition of Irk channels reduces BMP/Dpp signaling, and ultimately disrupts wing morphology. Ion channels impact development of several tissues and organisms in which BMP signaling is essential. In neurons and pancreatic beta cells, Irk channels modulate membrane potential to affect intracellular Ca++ to control secretion of neurotransmitters and insulin. Based on Irk activity in neurons, we hypothesized that electrical activity controls endoplasmic reticulum (ER) Ca++ release into the cytoplasm to regulate the release of BMP. Materials and Methods To test this hypothesis, we reduced expression of four proteins that control ER calcium, Stromal interaction molecule 1 (Stim), Calcium release-activated calcium channel protein 1 (Orai), SarcoEndoplasmic Reticulum Calcium ATPase (SERCA), small conductance calcium-activated potassium channel (SK), and Bestrophin 2 (Best2) using RNAi and documented wing phenotypes. We use live imaging to study calcium and Dpp release within pupal wings and larval wing discs. Additionally, we employed immunohistochemistry to characterize Small Mothers Against Decapentaplegic (SMAD) phosphorylation downstream of the BMP/Dpp pathway following RNAi knockdown. Results We found that reduced Stim and SERCA function decreases amplitude and frequency of endogenous calcium transients in the wing disc and reduced BMP/Dpp release. Conclusion Our results suggest control of ER calcium homeostasis is required for BMP/Dpp release, and Drosophila wing development.
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Affiliation(s)
- Laura Faith George
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Mikaela Lynn Follmer
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Emily Fontenoy
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hannah Rose Moran
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jeremy Ryan Brown
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Yunus H. Ozekin
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Emily Anne Bates
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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16
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Han Y, Yang J, Li Y, Chen Y, Ren H, Ding R, Qian W, Ren K, Xie B, Deng M, Xiao Y, Chu J, Zou P. Bright and sensitive red voltage indicators for imaging action potentials in brain slices and pancreatic islets. SCIENCE ADVANCES 2023; 9:eadi4208. [PMID: 37992174 PMCID: PMC10664999 DOI: 10.1126/sciadv.adi4208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 10/20/2023] [Indexed: 11/24/2023]
Abstract
Genetically encoded voltage indicators (GEVIs) allow the direct visualization of cellular membrane potential at the millisecond time scale. Among these, red-emitting GEVIs have been reported to support multichannel recordings and manipulation of cellular activities with reduced autofluorescence background. However, the limited sensitivity and dimness of existing red GEVIs have restricted their applications in neuroscience. Here, we report a pair of red-shifted opsin-based GEVIs, Cepheid1b and Cepheid1s, with improved dynamic range, brightness, and photostability. The improved dynamic range is achieved by a rational design to raise the electrochromic Förster resonance energy transfer efficiency, and the higher brightness and photostability are approached with separately engineered red fluorescent proteins. With Cepheid1 indicators, we recorded complex firings and subthreshold activities of neurons on acute brain slices and observed heterogeneity in the voltage‑calcium coupling on pancreatic islets. Overall, Cepheid1 indicators provide a strong tool to investigate excitable cells in various sophisticated biological systems.
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Affiliation(s)
- Yi Han
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Junqi Yang
- Peking University–Tsinghua University–National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yuan Li
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research (CIBR), Beijing 102206, China
| | - Yu Chen
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Huixia Ren
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Center for Quantitative Biology, Peking University, Beijing 100871, China
| | - Ran Ding
- Institute for Translational Neuroscience of the Second Affiliated Hospital of Nantong University, Center for Neural Developmental and Degenerative Research of Nantong University, Nantong 226001, China
| | - Weiran Qian
- Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China
| | - Keyuan Ren
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| | - Beichen Xie
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Mengying Deng
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yinghan Xiao
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jun Chu
- Research Center for Biomedical Optics and Molecular Imaging, Shenzhen Key Laboratory for Molecular Imaging, Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Peng Zou
- College of Chemistry and Molecular Engineering, Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
- Peking University–Tsinghua University–National Institute of Biological Sciences Joint Graduate Program, School of Life Sciences, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Chinese Institute for Brain Research (CIBR), Beijing 102206, China
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17
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Jaffredo M, Krentz NAJ, Champon B, Duff CE, Nawaz S, Beer N, Honore C, Clark A, Rorsman P, Lang J, Gloyn AL, Raoux M, Hastoy B. Electrophysiological characterisation of iPSC-derived human β-like cells and an SLC30A8 disease model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.561014. [PMID: 37905040 PMCID: PMC10614917 DOI: 10.1101/2023.10.17.561014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
iPSC-derived human β-like cells (BLC) hold promise for both therapy and disease modelling, but their generation remains challenging and their functional analyses beyond transcriptomic and morphological assessments remain limited. Here, we validate an approach using multicellular and single cell electrophysiological tools to evaluate BLCs functions. The Multi-Electrode Arrays (MEAs) measuring the extracellular electrical activity revealed that BLCs are electrically coupled, produce slow potential (SP) signals like primary β-cells that are closely linked to insulin secretion. We also used high-resolution single-cell patch-clamp measurements to capture the exocytotic properties, and characterize voltage-gated sodium and calcium currents. These were comparable to those in primary β and EndoC-βH1 cells. The KATP channel conductance is greater than in human primary β cells which may account for the limited glucose responsiveness observed with MEA. We used MEAs to study the impact of the type 2 diabetes protective SLC30A8 allele (p.Lys34Serfs*50) and found that BLCs with this allele have stronger electrical coupling. Our data suggest that with an adapted approach BLCs from pioneer protocol can be used to evaluate the functional impact of genetic variants on β-cell function and coupling.
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Affiliation(s)
- Manon Jaffredo
- University of Bordeaux, CNRS, Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, Pessac, France
| | - Nicole A. J. Krentz
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Pediatrics, Stanford School of Medicine, Stanford University, CA, USA
| | - Benoite Champon
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Claire E. Duff
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Sameena Nawaz
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicola Beer
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Jochen Lang
- University of Bordeaux, CNRS, Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, Pessac, France
| | - Anna L. Gloyn
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Pediatrics, Stanford School of Medicine, Stanford University, CA, USA
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Matthieu Raoux
- University of Bordeaux, CNRS, Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, Pessac, France
| | - Benoit Hastoy
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
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18
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Vanheer L, Fantuzzi F, To SK, Schiavo A, Van Haele M, Ostyn T, Haesen T, Yi X, Janiszewski A, Chappell J, Rihoux A, Sawatani T, Roskams T, Pattou F, Kerr-Conte J, Cnop M, Pasque V. Inferring regulators of cell identity in the human adult pancreas. NAR Genom Bioinform 2023; 5:lqad068. [PMID: 37435358 PMCID: PMC10331937 DOI: 10.1093/nargab/lqad068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/17/2023] [Accepted: 06/28/2023] [Indexed: 07/13/2023] Open
Abstract
Cellular identity during development is under the control of transcription factors that form gene regulatory networks. However, the transcription factors and gene regulatory networks underlying cellular identity in the human adult pancreas remain largely unexplored. Here, we integrate multiple single-cell RNA-sequencing datasets of the human adult pancreas, totaling 7393 cells, and comprehensively reconstruct gene regulatory networks. We show that a network of 142 transcription factors forms distinct regulatory modules that characterize pancreatic cell types. We present evidence that our approach identifies regulators of cell identity and cell states in the human adult pancreas. We predict that HEYL, BHLHE41 and JUND are active in acinar, beta and alpha cells, respectively, and show that these proteins are present in the human adult pancreas as well as in human induced pluripotent stem cell (hiPSC)-derived islet cells. Using single-cell transcriptomics, we found that JUND represses beta cell genes in hiPSC-alpha cells. BHLHE41 depletion induced apoptosis in primary pancreatic islets. The comprehensive gene regulatory network atlas can be explored interactively online. We anticipate our analysis to be the starting point for a more sophisticated dissection of how transcription factors regulate cell identity and cell states in the human adult pancreas.
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Affiliation(s)
- Lotte Vanheer
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Federica Fantuzzi
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - San Kit To
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Andrea Schiavo
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Matthias Van Haele
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Tessa Ostyn
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Tine Haesen
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Xiaoyan Yi
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Adrian Janiszewski
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Joel Chappell
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Adrien Rihoux
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
| | - Toshiaki Sawatani
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Tania Roskams
- Department of Imaging and Pathology; Translational Cell and Tissue Research, KU Leuven and University Hospitals Leuven; Herestraat 49, B-3000 Leuven, Belgium
| | - Francois Pattou
- University of Lille, Inserm, CHU Lille, Institute Pasteur Lille, U1190-EGID, F-59000 Lille, France
- European Genomic Institute for Diabetes, F-59000 Lille, France
- University of Lille, F-59000 Lille, France
| | - Julie Kerr-Conte
- University of Lille, Inserm, CHU Lille, Institute Pasteur Lille, U1190-EGID, F-59000 Lille, France
- European Genomic Institute for Diabetes, F-59000 Lille, France
- University of Lille, F-59000 Lille, France
| | - Miriam Cnop
- ULB Center for Diabetes Research; Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
- Division of Endocrinology; Erasmus Hospital, Université Libre de Bruxelles; Route de Lennik 808, B-1070 Brussels, Belgium
| | - Vincent Pasque
- Department of Development and Regeneration; KU Leuven - University of Leuven; Single-cell Omics Institute and Leuven Stem Cell Institute, Herestraat 49, B-3000 Leuven, Belgium
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19
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Adlakha N. Disturbances in system dynamics of [Formula: see text] and [Formula: see text] perturbing insulin secretion in a pancreatic [Formula: see text]-cell due to type-2 diabetes. J Bioenerg Biomembr 2023:10.1007/s10863-023-09966-7. [PMID: 37418135 DOI: 10.1007/s10863-023-09966-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/27/2023] [Indexed: 07/08/2023]
Abstract
The individual study of [Formula: see text] and [Formula: see text] dynamics respectively in a [Formula: see text]-cell has yielded limited information about the cell functions. But the systems biology approaches for such studies have received very little attention by the research workers in the past. In the present work, a system-dynamics model for the interdependent [Formula: see text] and [Formula: see text] signaling that controls insulin secretion in a [Formula: see text]-cell has been suggested. A two-way feedback system of [Formula: see text] and [Formula: see text] has been considered and one-way feedback between [Formula: see text] and insulin has been implemented in the model. The finite element method along with the Crank-Nicolson method have been applied for simulation. Numerical results have been used to analyze the impact of perturbations in [Formula: see text] and [Formula: see text] dynamics on insulin secretion for normal and Type-2 diabetic conditions. The results reveal that Type-2 diabetes comes from abnormalities in insulin secretion caused by the perturbation in buffers and pumps (SERCA and PMCA).
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Affiliation(s)
- Neeru Adlakha
- Department of Mathematics and Humanities, SVNIT, Surat, 395007, Gujarat, India
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20
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Khajavi N, Riçku K, Schreier PCF, Gentz T, Beyerle P, Cruz E, Breit A, Reinach PS, Gudermann T. Chronic Mg 2+ Deficiency Does Not Impair Insulin Secretion in Mice. Cells 2023; 12:1790. [PMID: 37443824 PMCID: PMC10340716 DOI: 10.3390/cells12131790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
Magnesium is an essential mediator of a vast number of critical enzymatic cellular reactions in the human body. Some clinical epidemiological studies suggest that hypomagnesemia accounts for declines in insulin secretion in patients with type 2 diabetes (T2D); however, the results of various experimental studies do not support this notion. To address this discrepancy, we assessed the short- and long-term effects of hypomagnesemia on β-cell function and insulin secretion in primary mouse islets of Langerhans and in a mouse model of hypomagnesemia known as Trpm6Δ17 /fl;Villin1-Cre mice. We found that lowering the extracellular Mg2+ concentration from 1.2 mM to either 0.6 or 0.1 mM remarkably increased glucose-induced insulin secretion (GIIS) in primary islets isolated from C57BL/6 mice. Similarly, both the plasma insulin levels and GIIS rose in isolated islets of Trpm6Δ17 /fl;Villin1-Cre mice. We attribute these rises to augmented increases in intracellular Ca2+ oscillations in pancreatic β-cells. However, the glycemic metabolic profile was not impaired in Trpm6Δ17 /fl;Villin1-Cre mice, suggesting that chronic hypomagnesemia does not lead to insulin resistance. Collectively, the results of this study suggest that neither acute nor chronic Mg2+ deficiency suppresses glucose-induced rises in insulin secretion. Even though hypomagnesemia can be symptomatic of T2D, such deficiency may not account for declines in insulin release in this disease.
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Affiliation(s)
- Noushafarin Khajavi
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Klea Riçku
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Pascale C. F. Schreier
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Tanja Gentz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Philipp Beyerle
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Emmanuel Cruz
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Andreas Breit
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
| | - Peter S. Reinach
- Ophthalmology Department, Wenzhou Medical University, Wenzhou 325015, China;
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, LMU Munich, 80539 Munich, Germany; (K.R.); (P.C.F.S.); (T.G.); (P.B.); (E.C.); (A.B.)
- German Center for Lung Research, 81377 Munich, Germany
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21
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Reyes Fernandez PC, Wright CS, Farach-Carson MC, Thompson WR. Examining Mechanisms for Voltage-Sensitive Calcium Channel-Mediated Secretion Events in Bone Cells. Calcif Tissue Int 2023; 113:126-142. [PMID: 37261463 PMCID: PMC11008533 DOI: 10.1007/s00223-023-01097-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023]
Abstract
In addition to their well-described functions in cell excitability, voltage-sensitive calcium channels (VSCCs) serve a critical role in calcium (Ca2+)-mediated secretion of pleiotropic paracrine and endocrine factors, including those produced in bone. Influx of Ca2+ through VSCCs activates intracellular signaling pathways to modulate a variety of cellular processes that include cell proliferation, differentiation, and bone adaptation in response to mechanical stimuli. Less well understood is the role of VSCCs in the control of bone and calcium homeostasis mediated through secreted factors. In this review, we discuss the various functions of VSCCs in skeletal cells as regulators of Ca2+ dynamics and detail how these channels might control the release of bioactive factors from bone cells. Because VSCCs are druggable, a better understanding of the multiple functions of these channels in the skeleton offers the opportunity for developing new therapies to enhance and maintain bone and to improve systemic health.
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Affiliation(s)
- Perla C Reyes Fernandez
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN, 46202, USA
- Center for Musculoskeletal Health, Indiana University, Indianapolis, IN, 46202, USA
| | - Christian S Wright
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN, 46202, USA
- Center for Musculoskeletal Health, Indiana University, Indianapolis, IN, 46202, USA
| | - Mary C Farach-Carson
- Department of Diagnostic and Biomedical Sciences, School of Dentistry, The University of Texas Health Science Center at Houston, Houston, TX, 77054, USA
- Departments of BioSciences and Bioengineering, Rice University, Houston, TX, 77005, USA
| | - William R Thompson
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, IN, 46202, USA.
- Center for Musculoskeletal Health, Indiana University, Indianapolis, IN, 46202, USA.
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN, 46202, USA.
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22
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Ramanadham S, Turk J, Bhatnagar S. Noncanonical Regulation of cAMP-Dependent Insulin Secretion and Its Implications in Type 2 Diabetes. Compr Physiol 2023; 13:5023-5049. [PMID: 37358504 PMCID: PMC10809800 DOI: 10.1002/cphy.c220031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Impaired glucose tolerance (IGT) and β-cell dysfunction in insulin resistance associated with obesity lead to type 2 diabetes (T2D). Glucose-stimulated insulin secretion (GSIS) from β-cells occurs via a canonical pathway that involves glucose metabolism, ATP generation, inactivation of K ATP channels, plasma membrane depolarization, and increases in cytosolic concentrations of [Ca 2+ ] c . However, optimal insulin secretion requires amplification of GSIS by increases in cyclic adenosine monophosphate (cAMP) signaling. The cAMP effectors protein kinase A (PKA) and exchange factor activated by cyclic-AMP (Epac) regulate membrane depolarization, gene expression, and trafficking and fusion of insulin granules to the plasma membrane for amplifying GSIS. The widely recognized lipid signaling generated within β-cells by the β-isoform of Ca 2+ -independent phospholipase A 2 enzyme (iPLA 2 β) participates in cAMP-stimulated insulin secretion (cSIS). Recent work has identified the role of a G-protein coupled receptor (GPCR) activated signaling by the complement 1q like-3 (C1ql3) secreted protein in inhibiting cSIS. In the IGT state, cSIS is attenuated, and the β-cell function is reduced. Interestingly, while β-cell-specific deletion of iPLA 2 β reduces cAMP-mediated amplification of GSIS, the loss of iPLA 2 β in macrophages (MØ) confers protection against the development of glucose intolerance associated with diet-induced obesity (DIO). In this article, we discuss canonical (glucose and cAMP) and novel noncanonical (iPLA 2 β and C1ql3) pathways and how they may affect β-cell (dys)function in the context of impaired glucose intolerance associated with obesity and T2D. In conclusion, we provide a perspective that in IGT states, targeting noncanonical pathways along with canonical pathways could be a more comprehensive approach for restoring β-cell function in T2D. © 2023 American Physiological Society. Compr Physiol 13:5023-5049, 2023.
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Affiliation(s)
- Sasanka Ramanadham
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Alabama, USA
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
| | - John Turk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sushant Bhatnagar
- Comprehensive Diabetes Center, University of Alabama at Birmingham, Alabama, USA
- Department of Medicine, University of Alabama at Birmingham, Alabama, USA
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23
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Wen L, Yang X, Wu Z, Fu S, Zhan Y, Chen Z, Bi D, Shen Y. The complement inhibitor CD59 is required for GABAergic synaptic transmission in the dentate gyrus. Cell Rep 2023; 42:112349. [PMID: 37027303 DOI: 10.1016/j.celrep.2023.112349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 01/31/2023] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
Complement-dependent microglia pruning of excitatory synapses has been widely reported in physiological and pathological conditions, with few reports concerning pruning of inhibitory synapses or direct regulation of synaptic transmission by complement components. Here, we report that loss of CD59, an important endogenous inhibitor of the complement system, leads to compromised spatial memory performance. Furthermore, CD59 deficiency impairs GABAergic synaptic transmission in the hippocampal dentate gyrus (DG). This depends on regulation of GABA release triggered by Ca2+ influx through voltage-gated calcium channels (VGCCs) rather than inhibitory synaptic pruning by microglia. Notably, CD59 colocalizes with inhibitory pre-synaptic terminals and regulates SNARE complex assembly. Together, these results demonstrate that the complement regulator CD59 plays an important role in normal hippocampal function.
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Affiliation(s)
- Lang Wen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Xiaoli Yang
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Zujun Wu
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Shumei Fu
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Yaxi Zhan
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Zuolong Chen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215000, China
| | - Danlei Bi
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei 230026, China; Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
| | - Yong Shen
- Department of Neurology and Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Neurodegenerative Disease Research Center, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei 230026, China; CAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China, Hefei 230026, China; Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
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24
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Tariq M, de Souza AH, Bensellam M, Chae H, Jaffredo M, Close AF, Deglasse JP, Santos LRB, Buemi A, Mourad NI, Wojtusciszyn A, Raoux M, Gilon P, Broca C, Jonas JC. Prolonged culture of human pancreatic islets under glucotoxic conditions changes their acute beta cell calcium and insulin secretion glucose response curves from sigmoid to bell-shaped. Diabetologia 2023; 66:709-723. [PMID: 36459178 DOI: 10.1007/s00125-022-05842-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 10/18/2022] [Indexed: 12/04/2022]
Abstract
AIMS/HYPOTHESIS The rapid remission of type 2 diabetes by a diet very low in energy correlates with a marked improvement in glucose-stimulated insulin secretion (GSIS), emphasising the role of beta cell dysfunction in the early stages of the disease. In search of novel mechanisms of beta cell dysfunction after long-term exposure to mild to severe glucotoxic conditions, we extensively characterised the alterations in insulin secretion and upstream coupling events in human islets cultured for 1-3 weeks at ~5, 8, 10 or 20 mmol/l glucose and subsequently stimulated by an acute stepwise increase in glucose concentration. METHODS Human islets from 49 non-diabetic donors (ND-islets) and six type 2 diabetic donors (T2D-islets) were obtained from five isolation centres. After shipment, the islets were precultured for 3-7 days in RPMI medium containing ~5 mmol/l glucose and 10% (vol/vol) heat-inactivated FBS with selective islet picking at each medium renewal. Islets were then cultured for 1-3 weeks in RPMI containing ~5, 8, 10 or 20 mmol/l glucose before measurement of insulin secretion during culture, islet insulin and DNA content, beta cell apoptosis and cytosolic and mitochondrial glutathione redox state, and assessment of dynamic insulin secretion and upstream coupling events during acute stepwise stimulation with glucose [NAD(P)H autofluorescence, ATP/(ATP+ADP) ratio, electrical activity, cytosolic Ca2+ concentration ([Ca2+]c)]. RESULTS Culture of ND-islets for 1-3 weeks at 8, 10 or 20 vs 5 mmol/l glucose did not significantly increase beta cell apoptosis or oxidative stress but decreased insulin content in a concentration-dependent manner and increased beta cell sensitivity to subsequent acute stimulation with glucose. Islet glucose responsiveness was higher after culture at 8 or 10 vs 5 mmol/l glucose and markedly reduced after culture at 20 vs 5 mmol/l glucose. In addition, the [Ca2+]c and insulin secretion responses to acute stepwise stimulation with glucose were no longer sigmoid but bell-shaped, with maximal stimulation at 5 or 10 mmol/l glucose and rapid sustained inhibition above that concentration. Such paradoxical inhibition was, however, no longer observed when islets were acutely depolarised by 30 mmol/l extracellular K+. The glucotoxic alterations of beta cell function were fully reversible after culture at 5 mmol/l glucose and were mimicked by pharmacological activation of glucokinase during culture at 5 mmol/l glucose. Similar results to those seen in ND-islets were obtained in T2D-islets, except that their rate of insulin secretion during culture at 8 and 20 mmol/l glucose was lower, their cytosolic glutathione oxidation increased after culture at 8 and 20 mmol/l glucose, and the alterations in GSIS and upstream coupling events were greater after culture at 8 mmol/l glucose. CONCLUSIONS/INTERPRETATION Prolonged culture of human islets under moderate to severe glucotoxic conditions markedly increased their glucose sensitivity and revealed a bell-shaped acute glucose response curve for changes in [Ca2+]c and insulin secretion, with maximal stimulation at 5 or 10 mmol/l glucose and rapid inhibition above that concentration. This novel glucotoxic alteration may contribute to beta cell dysfunction in type 2 diabetes independently from a detectable increase in beta cell apoptosis.
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Affiliation(s)
- Mohammad Tariq
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Arnaldo H de Souza
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Mohammed Bensellam
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Heeyoung Chae
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Manon Jaffredo
- CNRS, Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, University of Bordeaux, Pessac, France
| | - Anne-Françoise Close
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Philippe Deglasse
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Laila R B Santos
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
- Bio Base Europe Pilot Plant (BBEPP), Ghent, Belgium
| | - Antoine Buemi
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle de chirurgie expérimentale, Université catholique de Louvain, Brussels, Belgium
| | - Nizar I Mourad
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle de chirurgie expérimentale, Université catholique de Louvain, Brussels, Belgium
| | - Anne Wojtusciszyn
- Laboratoire de Thérapie Cellulaire du Diabète, Institut de Médecine Régénérative et Biothérapies, Hôpital St Eloi, CHU Montpellier, Montpellier, France
- Service d'Endocrinologie, Diabétologie et Métabolisme, Centre Hospitalier Universitaire Vaudois and Université de Lausanne, Lausanne, Switzerland
| | - Matthieu Raoux
- CNRS, Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, University of Bordeaux, Pessac, France
| | - Patrick Gilon
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Christophe Broca
- Laboratoire de Thérapie Cellulaire du Diabète, Institut de Médecine Régénérative et Biothérapies, Hôpital St Eloi, CHU Montpellier, Montpellier, France
| | - Jean-Christophe Jonas
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium.
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25
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Galvis D, Hodson DJ, Wedgwood KC. Spatial distribution of heterogeneity as a modulator of collective dynamics in pancreatic beta-cell networks and beyond. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:fnetp.2023.1170930. [PMID: 36987428 PMCID: PMC7614376 DOI: 10.3389/fnetp.2023.1170930] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
We study the impact of spatial distribution of heterogeneity on collective dynamics in gap-junction coupled beta-cell networks comprised on cells from two populations that differ in their intrinsic excitability. Initially, these populations are uniformly and randomly distributed throughout the networks. We develop and apply an iterative algorithm for perturbing the arrangement of the network such that cells from the same population are increasingly likely to be adjacent to one another. We find that the global input strength, or network drive, necessary to transition the network from a state of quiescence to a state of synchronised and oscillatory activity decreases as network sortedness increases. Moreover, for weak coupling, we find that regimes of partial synchronisation and wave propagation arise, which depend both on network drive and network sortedness. We then demonstrate the utility of this algorithm for studying the distribution of heterogeneity in general networks, for which we use Watts-Strogatz networks as a case study. This work highlights the importance of heterogeneity in node dynamics in establishing collective rhythms in complex, excitable networks and has implications for a wide range of real-world systems that exhibit such heterogeneity.
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Affiliation(s)
- Daniel Galvis
- Centre for Systems Modelling and Quantitative Biomedicine, University of Birmingham, Birmingham, UK
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Correspondence: Daniel Galvis,
| | - David J. Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
- Oxford Centre for Diabetes, Endocrinology, and Metabolism (OCDEM), Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Kyle C.A. Wedgwood
- Living Systems Institute, University of Exeter, Exeter, UK
- EPSRC Hub for Quantitative Modelling in Healthcare, University of Exeter, Exeter, UK
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
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26
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Lodato M, Plaisance V, Pawlowski V, Kwapich M, Barras A, Buissart E, Dalle S, Szunerits S, Vicogne J, Boukherroub R, Abderrahmani A. Venom Peptides, Polyphenols and Alkaloids: Are They the Next Antidiabetics That Will Preserve β-Cell Mass and Function in Type 2 Diabetes? Cells 2023; 12:cells12060940. [PMID: 36980281 PMCID: PMC10047094 DOI: 10.3390/cells12060940] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/09/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
Improvement of insulin secretion by pancreatic β-cells and preservation of their mass are the current challenges that future antidiabetic drugs should meet for achieving efficient and long-term glycemic control in patients with type 2 diabetes (T2D). The successful development of glucagon-like peptide 1 (GLP-1) analogues, derived from the saliva of a lizard from the Helodermatidae family, has provided the proof of concept that antidiabetic drugs directly targeting pancreatic β-cells can emerge from venomous animals. The literature reporting on the antidiabetic effects of medicinal plants suggests that they contain some promising active substances such as polyphenols and alkaloids, which could be active as insulin secretagogues and β-cell protectors. In this review, we discuss the potential of several polyphenols, alkaloids and venom peptides from snake, frogs, scorpions and cone snails. These molecules could contribute to the development of new efficient antidiabetic medicines targeting β-cells, which would tackle the progression of the disease.
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Affiliation(s)
- Michele Lodato
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Valérie Plaisance
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Valérie Pawlowski
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Maxime Kwapich
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
- Service de Diabétologie et d’Endocrinologie, CH Dunkerque, 59385 Dunkirk, France
| | - Alexandre Barras
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Emeline Buissart
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Stéphane Dalle
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Sabine Szunerits
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Jérôme Vicogne
- University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR 9017-CIIL-Center for Infection and Immunity of Lille, F-59000 Lille, France
| | - Rabah Boukherroub
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
| | - Amar Abderrahmani
- University Lille, CNRS, Centrale Lille, University Polytechnique Hauts-de-France, UMR 8520, IEMN, F-59000 Lille, France
- Correspondence: ; Tel.: +33-362531704
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In Vivo CaV3 Channel Inhibition Promotes Maturation of Glucose-Dependent Ca2+ Signaling in Human iPSC-Islets. Biomedicines 2023; 11:biomedicines11030807. [PMID: 36979793 PMCID: PMC10045717 DOI: 10.3390/biomedicines11030807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 02/26/2023] [Accepted: 03/02/2023] [Indexed: 03/10/2023] Open
Abstract
CaV3 channels are ontogenetically downregulated with the maturation of certain electrically excitable cells, including pancreatic β cells. Abnormally exaggerated CaV3 channels drive the dedifferentiation of mature β cells. This led us to question whether excessive CaV3 channels, retained mistakenly in engineered human-induced pluripotent stem cell-derived islet (hiPSC-islet) cells, act as an obstacle to hiPSC-islet maturation. We addressed this question by using the anterior chamber of the eye (ACE) of immunodeficient mice as a site for recapitulation of in vivo hiPSC-islet maturation in combination with intravitreal drug infusion, intravital microimaging, measurements of cytoplasmic-free Ca2+ concentration ([Ca2+]i) and patch clamp analysis. We observed that the ACE is well suited for recapitulation, observation and intervention of hiPSC-islet maturation. Intriguingly, intraocular hiPSC-islet grafts, retrieved intact following intravitreal infusion of the CaV3 channel blocker NNC55-0396, exhibited decreased basal [Ca2+]i levels and increased glucose-stimulated [Ca2+]i responses. Insulin-expressing cells of these islet grafts indeed expressed the NNC55-0396 target CaV3 channels. Intraocular hiPSC-islets underwent satisfactory engraftment, vascularization and light scattering without being influenced by the intravitreally infused NNC55-0396. These data demonstrate that inhibiting CaV3 channels facilitates the maturation of glucose-activated Ca2+ signaling in hiPSC-islets, supporting the notion that excessive CaV3 channels as a developmental error impede the maturation of engineer ed hiPSC-islet insulin-expressing cells.
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Turbitt J, Brennan L, Moffett RC, Flatt PR, Johnson PRV, Tarasov AI, McClenaghan NH. NKCC transport mediates the insulinotropic effects of taurine and other small neutral amino acids. Life Sci 2023; 316:121402. [PMID: 36669678 DOI: 10.1016/j.lfs.2023.121402] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 01/04/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023]
Abstract
AIMS Despite its high concentration in pancreatic islets of Langerhans and broad range of antihyperglycemic effects, the route facilitating the import of dietary taurine into pancreatic β-cell and mechanisms underlying its insulinotropic activity are unclear. We therefore studied the impact of taurine on beta-cell function, alongside that of other small neutral amino acids, L-alanine and L-proline. MAIN METHODS Pharmacological profiling of insulin secretion was conducted using clonal BRIN BD11 β-cells, the impact of taurine on the metabolic fate of glucose carbons was assessed using NMR and the findings were verified by real-time imaging of Ca2+ dynamics in the cytosol of primary mouse and human islet beta-cells. KEY FINDINGS In our hands, taurine, alanine and proline induced secretory responses that were dependent on the plasma membrane depolarisation, import of Ca2+, homeostasis of K+ and Na+ as well as on cell glycolytic and oxidative metabolism. Taurine shifted the balance between the oxidation and anaplerosis towards the latter, in BRIN BD11 beta-cells. Furthermore, the amino acid signalling was significantly attenuated by inhibition of Na+-K+-Cl- symporter (NKCC). SIGNIFICANCE These data suggest that taurine, like L-alanine and L-proline, acutely induces glucose-dependent insulin-secretory responses by modulating electrogenic Na+ transport, with potential role of intracellular K+ and Cl- in the signal transduction. The acute action delineated would be consistent with antidiabetic potential of dietary taurine supplementation.
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Affiliation(s)
- Julie Turbitt
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK
| | - Lorraine Brennan
- UCD Institute of Food and Health, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland; UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
| | - R Charlotte Moffett
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK.
| | - Peter R Flatt
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK.
| | - Paul R V Johnson
- Nuffeld Department of Surgical Sciences, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Headington, OX3 7LE Oxford, UK; Oxford Biomedical Research Centre (OxBRC), UK.
| | - Andrei I Tarasov
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK; Nuffeld Department of Surgical Sciences, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Headington, OX3 7LE Oxford, UK; Oxford Biomedical Research Centre (OxBRC), UK.
| | - Neville H McClenaghan
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK; Department of Life Sciences, Atlantic Technological University, Ash Lane, Sligo, F91 YW50, Ireland.
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29
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Li K, Bian J, Xiao Y, Wang D, Han L, He C, Gong L, Wang M. Changes in Pancreatic Senescence Mediate Pancreatic Diseases. Int J Mol Sci 2023; 24:ijms24043513. [PMID: 36834922 PMCID: PMC9962587 DOI: 10.3390/ijms24043513] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
In recent years, there has been a significant increase in age-related diseases due to the improvement in life expectancy worldwide. The pancreas undergoes various morphological and pathological changes with aging, such as pancreatic atrophy, fatty degeneration, fibrosis, inflammatory cell infiltration, and exocrine pancreatic metaplasia. Meanwhile, these may predispose the individuals to aging-related diseases, such as diabetes, dyspepsia, pancreatic ductal adenocarcinoma, and pancreatitis, as the endocrine and exocrine functions of the pancreas are significantly affected by aging. Pancreatic senescence is associated with various underlying factors including genetic damage, DNA methylation, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and inflammation. This paper reviews the alternations of morphologies and functions in the aging pancreas, especially β-cells, closely related to insulin secretion. Finally, we summarize the mechanisms of pancreatic senescence to provide potential targets for treating pancreatic aging-related diseases.
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Affiliation(s)
- Kailin Li
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Ji Bian
- Kolling Institute, Sydney Medical School, Royal North Shore Hospital, University of Sydney, St. Leonards, NSW 2065, Australia
| | - Yao Xiao
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Da Wang
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Lin Han
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Caian He
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Lan Gong
- Microbiome Research Centre, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
- Correspondence: (L.G.); (M.W.)
| | - Min Wang
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
- Correspondence: (L.G.); (M.W.)
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30
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Müller M, Walkling J, Seemann N, Rustenbeck I. The Dynamics of Calcium Signaling in Beta Cells-A Discussion on the Comparison of Experimental and Modelling Data. Int J Mol Sci 2023; 24:ijms24043206. [PMID: 36834618 PMCID: PMC9960854 DOI: 10.3390/ijms24043206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 02/07/2023] Open
Abstract
The stimulus-secretion coupling of the pancreatic beta cell is particularly complex, as it integrates the availability of glucose and other nutrients with the neuronal and hormonal input to generate rates of insulin secretion that are appropriate for the entire organism. It is beyond dispute however, that the cytosolic Ca2+ concentration plays a particularly prominent role in this process, as it not only triggers the fusion of insulin granules with the plasma membrane, but also regulates the metabolism of nutrient secretagogues and affects the function of ion channels and transporters. In order to obtain a better understanding of the interdependence of these processes and, ultimately, of the entire beta cell as a working system, models have been developed based on a set of nonlinear ordinary differential equations, and were tested and parametrized on a limited set of experiments. In the present investigation, we have used a recently published version of the beta cell model to test its ability to describe further measurements from our own experimentation and from the literature. The sensitivity of the parameters is quantified and discussed; furthermore, the possible influence of the measuring technique is taken into account. The model proved to be powerful in correctly describing the depolarization pattern in response to glucose and the reaction of the cytosolic Ca2+ concentration to stepwise increases of the extracellular K+ concentration. Additionally, the membrane potential during a KATP channel block combined with a high extracellular K+ concentration could be reproduced. In some cases, however, a slight change of a single parameter led to an abrupt change in the cellular response, such as the generation of a Ca2+ oscillation with high amplitude and high frequency. This raises the question as to whether the beta cell may be a partially unstable system or whether further developments in modeling are needed to achieve a generally valid description of the stimulus-secretion coupling of the beta cell.
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Affiliation(s)
- Michael Müller
- Institute of Dynamics and Vibrations, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
- Correspondence: (M.M.); (I.R.); Tel.: +49-531-391-7005 (M.M.);+49-531-391-5670 (I.R.)
| | - Jonas Walkling
- Institute of Dynamics and Vibrations, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Nele Seemann
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
| | - Ingo Rustenbeck
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, D-38106 Braunschweig, Germany
- Correspondence: (M.M.); (I.R.); Tel.: +49-531-391-7005 (M.M.);+49-531-391-5670 (I.R.)
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31
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Hermann FM, Kjærgaard MF, Tian C, Tiemann U, Jackson A, Olsen LR, Kraft M, Carlsson PO, Elfving IM, Kettunen JLT, Tuomi T, Novak I, Semb H. An insulin hypersecretion phenotype precedes pancreatic β cell failure in MODY3 patient-specific cells. Cell Stem Cell 2023; 30:38-51.e8. [PMID: 36563694 DOI: 10.1016/j.stem.2022.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 10/04/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
MODY3 is a monogenic hereditary form of diabetes caused by mutations in the transcription factor HNF1A. The patients progressively develop hyperglycemia due to perturbed insulin secretion, but the pathogenesis is unknown. Using patient-specific hiPSCs, we recapitulate the insulin secretion sensitivity to the membrane depolarizing agent sulfonylurea commonly observed in MODY3 patients. Unexpectedly, MODY3 patient-specific HNF1A+/R272C β cells hypersecrete insulin both in vitro and in vivo after transplantation into mice. Consistently, we identified a trend of increased birth weight in human HNF1A mutation carriers compared with healthy siblings. Reduced expression of potassium channels, specifically the KATP channel, in MODY3 β cells, increased calcium signaling, and rescue of the insulin hypersecretion phenotype by pharmacological targeting ATP-sensitive potassium channels or low-voltage-activated calcium channels suggest that more efficient membrane depolarization underlies the hypersecretion of insulin in MODY3 β cells. Our findings identify a pathogenic mechanism leading to β cell failure in MODY3.
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Affiliation(s)
- Florian M Hermann
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Maya Friis Kjærgaard
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Chenglei Tian
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark; Institute of Translational Stem Cell Research, Helmholtz Diabetes Center, Helmholtz Zentrum München, München, Germany
| | - Ulf Tiemann
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Abigail Jackson
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Lars Rønn Olsen
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Maria Kraft
- Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden; Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Jarno L T Kettunen
- Folkhalsan Research Center, Helsinki, Finland; Institute for Molecular Medicine Finland, University of Finland, Helsinki, Finland; Department of Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Tiinamaija Tuomi
- Folkhalsan Research Center, Helsinki, Finland; Institute for Molecular Medicine Finland, University of Finland, Helsinki, Finland; Department of Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Semb
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark; Institute of Translational Stem Cell Research, Helmholtz Diabetes Center, Helmholtz Zentrum München, München, Germany.
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32
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Harvey KE, Tang S, LaVigne EK, Pratt EPS, Hockerman GH. RyR2 regulates store-operated Ca2+ entry, phospholipase C activity, and electrical excitability in the insulinoma cell line INS-1. PLoS One 2023; 18:e0285316. [PMID: 37141277 PMCID: PMC10159205 DOI: 10.1371/journal.pone.0285316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
The ER Ca2+ channel ryanodine receptor 2 (RyR2) is required for maintenance of insulin content and glucose-stimulated insulin secretion, in part, via regulation of the protein IRBIT in the insulinoma cell line INS-1. Here, we examined store-operated and depolarization-dependent Ca2+entry using INS-1 cells in which either RyR2 or IRBIT were deleted. Store-operated Ca2+ entry (SOCE) stimulated with thapsigargin was reduced in RyR2KO cells compared to controls, but was unchanged in IRBITKO cells. STIM1 protein levels were not different between the three cell lines. Basal and stimulated (500 μM carbachol) phospholipase C (PLC) activity was also reduced specifically in RyR2KO cells. Insulin secretion stimulated by tolbutamide was reduced in RyR2KO and IRBITKO cells compared to controls, but was potentiated by an EPAC-selective cAMP analog in all three cell lines. Cellular PIP2 levels were increased and cortical f-actin levels were reduced in RyR2KO cells compared to controls. Whole-cell Cav channel current density was increased in RyR2KO cells compared to controls, and barium current was reduced by acute activation of the lipid phosphatase pseudojanin preferentially in RyR2KO cells over control INS-1 cells. Action potentials stimulated by 18 mM glucose were more frequent in RyR2KO cells compared to controls, and insensitive to the SK channel inhibitor apamin. Taken together, these results suggest that RyR2 plays a critical role in regulating PLC activity and PIP2 levels via regulation of SOCE. RyR2 also regulates β-cell electrical activity by controlling Cav current density and SK channel activation.
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Affiliation(s)
- Kyle E Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Shiqi Tang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Emily K LaVigne
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Evan P S Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
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33
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Rottner AK, Ye Y, Navarro-Guerrero E, Rajesh V, Pollner A, Bevacqua RJ, Yang J, Spigelman AF, Baronio R, Bautista A, Thomsen SK, Lyon J, Nawaz S, Smith N, Wesolowska-Andersen A, Fox JEM, Sun H, Kim SK, Ebner D, MacDonald PE, Gloyn AL. A genome-wide CRISPR screen identifies CALCOCO2 as a regulator of beta cell function influencing type 2 diabetes risk. Nat Genet 2023; 55:54-65. [PMID: 36543916 PMCID: PMC9839450 DOI: 10.1038/s41588-022-01261-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/26/2022] [Indexed: 12/24/2022]
Abstract
Identification of the genes and processes mediating genetic association signals for complex diseases represents a major challenge. As many of the genetic signals for type 2 diabetes (T2D) exert their effects through pancreatic islet-cell dysfunction, we performed a genome-wide pooled CRISPR loss-of-function screen in a human pancreatic beta cell line. We assessed the regulation of insulin content as a disease-relevant readout of beta cell function and identified 580 genes influencing this phenotype. Integration with genetic and genomic data provided experimental support for 20 candidate T2D effector transcripts including the autophagy receptor CALCOCO2. Loss of CALCOCO2 was associated with distorted mitochondria, less proinsulin-containing immature granules and accumulation of autophagosomes upon inhibition of late-stage autophagy. Carriers of T2D-associated variants at the CALCOCO2 locus further displayed altered insulin secretion. Our study highlights how cellular screens can augment existing multi-omic efforts to support mechanistic understanding and provide evidence for causal effects at genome-wide association studies loci.
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Affiliation(s)
- Antje K Rottner
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Yingying Ye
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Elena Navarro-Guerrero
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Varsha Rajesh
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Alina Pollner
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Romina J Bevacqua
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Diabetes Research Centre, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Jing Yang
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Aliya F Spigelman
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Roberta Baronio
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Austin Bautista
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Soren K Thomsen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - James Lyon
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Sameena Nawaz
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nancy Smith
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | | | - Jocelyn E Manning Fox
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Han Sun
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Diabetes Research Centre, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Daniel Ebner
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA
| | - Patrick E MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Anna L Gloyn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
- Department of Pediatrics, Division of Endocrinology, Stanford School of Medicine, Stanford University, Stanford, CA, USA.
- Stanford Diabetes Research Centre, Stanford School of Medicine, Stanford University, Stanford, CA, USA.
- Oxford NIHR Biomedical Research Centre, Oxford University Hospitals Trust, Oxford, UK.
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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Essaouiba A, Jellali R, Gilard F, Gakière B, Okitsu T, Legallais C, Sakai Y, Leclerc E. Investigation of the Exometabolomic Profiles of Rat Islets of Langerhans Cultured in Microfluidic Biochip. Metabolites 2022; 12:metabo12121270. [PMID: 36557308 PMCID: PMC9786643 DOI: 10.3390/metabo12121270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Diabetes mellitus (DM) is a complex disease with high prevalence of comorbidity and mortality. DM is predicted to reach more than 700 million people by 2045. In recent years, several advanced in vitro models and analytical tools were developed to investigate the pancreatic tissue response to pathological situations and identify therapeutic solutions. Of all the in vitro promising models, cell culture in microfluidic biochip allows the reproduction of in-vivo-like micro-environments. Here, we cultured rat islets of Langerhans using dynamic cultures in microfluidic biochips. The dynamic cultures were compared to static islets cultures in Petri. The islets' exometabolomic signatures, with and without GLP1 and isradipine treatments, were characterized by GC-MS. Compared to Petri, biochip culture contributes to maintaining high secretions of insulin, C-peptide and glucagon. The exometabolomic profiling revealed 22 and 18 metabolites differentially expressed between Petri and biochip on Day 3 and 5. These metabolites illustrated the increase in lipid metabolism, the perturbation of the pentose phosphate pathway and the TCA cycle in biochip. After drug stimulations, the exometabolome of biochip culture appeared more perturbed than the Petri exometabolome. The GLP1 contributed to the increase in the levels of glycolysis, pentose phosphate and glutathione pathways intermediates, whereas isradipine led to reduced levels of lipids and carbohydrates.
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Affiliation(s)
- Amal Essaouiba
- Biomechanics and Bioengineering, CNRS, Université de Technologie de Compiègne, Centre de Recherche Royallieu CS 60319, 60203 Compiègne, France
- CNRS IRL 2820, Laboratory for Integrated Micro Mechatronic Systems, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Rachid Jellali
- Biomechanics and Bioengineering, CNRS, Université de Technologie de Compiègne, Centre de Recherche Royallieu CS 60319, 60203 Compiègne, France
- Correspondence: (R.J.); (E.L.)
| | - Françoise Gilard
- Plateforme Métabolisme-Métabolome, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, CNRS, INRAE, Université Evry, Université Paris Cité, Bâtiment 360, Avenue des Sciences, 91190 Gif sur Yvette, France
| | - Bertrand Gakière
- Plateforme Métabolisme-Métabolome, Institute of Plant Sciences Paris-Saclay (IPS2), Université Paris-Saclay, CNRS, INRAE, Université Evry, Université Paris Cité, Bâtiment 360, Avenue des Sciences, 91190 Gif sur Yvette, France
| | - Teru Okitsu
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Cécile Legallais
- Biomechanics and Bioengineering, CNRS, Université de Technologie de Compiègne, Centre de Recherche Royallieu CS 60319, 60203 Compiègne, France
| | - Yasuyuki Sakai
- CNRS IRL 2820, Laboratory for Integrated Micro Mechatronic Systems, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Department of Chemical Engineering, Faculty of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Eric Leclerc
- Biomechanics and Bioengineering, CNRS, Université de Technologie de Compiègne, Centre de Recherche Royallieu CS 60319, 60203 Compiègne, France
- CNRS IRL 2820, Laboratory for Integrated Micro Mechatronic Systems, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Correspondence: (R.J.); (E.L.)
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35
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McLaughlin K, Acreman S, Nawaz S, Cutteridge J, Clark A, Knudsen JG, Denwood G, Spigelman AF, Manning Fox JE, Singh SP, MacDonald PE, Hastoy B, Zhang Q. Loss of tetraspanin-7 expression reduces pancreatic β-cell exocytosis Ca 2+ sensitivity but has limited effect on systemic metabolism. Diabet Med 2022; 39:e14984. [PMID: 36264270 PMCID: PMC9828109 DOI: 10.1111/dme.14984] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/08/2022] [Accepted: 10/18/2022] [Indexed: 01/18/2023]
Abstract
BACKGROUND Tetraspanin-7 (Tspan7) is an islet autoantigen involved in autoimmune type 1 diabetes and known to regulate β-cell L-type Ca2+ channel activity. However, the role of Tspan7 in pancreatic β-cell function is not yet fully understood. METHODS Histological analyses were conducted using immunostaining. Whole-body metabolism was tested using glucose tolerance test. Islet hormone secretion was quantified using static batch incubation or dynamic perifusion. β-cell transmembrane currents, electrical activity and exocytosis were measured using whole-cell patch-clamping and capacitance measurements. Gene expression was studied using mRNA-sequencing and quantitative PCR. RESULTS Tspan7 is expressed in insulin-containing granules of pancreatic β-cells and glucagon-producing α-cells. Tspan7 knockout mice (Tspan7y/- mouse) exhibit reduced body weight and ad libitum plasma glucose but normal glucose tolerance. Tspan7y/- islets have normal insulin content and glucose- or tolbutamide-stimulated insulin secretion. Depolarisation-triggered Ca2+ current was enhanced in Tspan7y/- β-cells, but β-cell electrical activity and depolarisation-evoked exocytosis were unchanged suggesting that exocytosis was less sensitive to Ca2+ . TSPAN7 knockdown (KD) in human pseudo-islets led to a significant reduction in insulin secretion stimulated by 20 mM K+ . Transcriptomic analyses show that TSPAN7 KD in human pseudo-islets correlated with changes in genes involved in hormone secretion, apoptosis and ER stress. Consistent with rodent β-cells, exocytotic Ca2+ sensitivity was reduced in a human β-cell line (EndoC-βH1) following Tspan7 KD. CONCLUSION Tspan7 is involved in the regulation of Ca2+ -dependent exocytosis in β-cells. Its function is more significant in human β-cells than their rodent counterparts.
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Affiliation(s)
- Kerry McLaughlin
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Samuel Acreman
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
- Institute of Neuroscience and Physiology, Department of Physiology, Metabolic Research UnitUniversity of GoteborgGöteborgSweden
| | - Sameena Nawaz
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Joseph Cutteridge
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Jakob G. Knudsen
- Section for Cell Biology and Physiology, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Geoffrey Denwood
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Aliya F. Spigelman
- Alberta Diabetes Institute and Department of PharmacologyUniversity of AlbertaEdmontonAlbertaCanada
| | - Jocelyn E. Manning Fox
- Alberta Diabetes Institute and Department of PharmacologyUniversity of AlbertaEdmontonAlbertaCanada
| | | | - Patrick E. MacDonald
- Alberta Diabetes Institute and Department of PharmacologyUniversity of AlbertaEdmontonAlbertaCanada
| | - Benoit Hastoy
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and MetabolismUniversity of Oxford, Churchill HospitalOxfordUK
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36
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Andrean D, Pedersen MG. Machine learning provides insight into models of heterogeneous electrical activity in human beta-cells. Math Biosci 2022; 354:108927. [PMID: 36332730 DOI: 10.1016/j.mbs.2022.108927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Understanding how heterogeneous cellular responses emerge from cell-to-cell variations in expression and function of subcellular components is of general interest. Here, we focus on human insulin-secreting beta-cells, which are believed to constitute a population in which heterogeneity is of physiological importance. We exploit recent single-cell electrophysiological data that allow biologically realistic population modeling of human beta-cells that accounts for cellular heterogeneity and correlation between ion channel parameters. To investigate how ion channels influence the dynamics of our updated mathematical model of human pancreatic beta-cells, we explore several machine learning techniques to determine which model parameters are important for determining the qualitative patterns of electrical activity of the model cells. As expected, K+ channels promote absence of activity, but once a cell is active, they increase the likelihood of having action potential firing. HERG channels were of great importance for determining cell behavior in most of the investigated scenarios. Fast bursting is influenced by the time scales of ion channel activation and, interestingly, by the type of Ca2+ channels coupled to BK channels in BK-CaV complexes. Slow, metabolically driven oscillations are promoted mostly by K(ATP) channels. In summary, combining population modeling with machine learning analysis provides insight into the model and generates new hypotheses to be investigated both experimentally, via simulations and through mathematical analysis.
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Affiliation(s)
- Daniele Andrean
- Department of Information Engineering, University of Padova, Via Gradenigo 6/b, I-35131 Padova, Italy
| | - Morten Gram Pedersen
- Department of Information Engineering, University of Padova, Via Gradenigo 6/b, I-35131 Padova, Italy.
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Yan X, Zhao Z, Weaver J, Sun T, Yun JW, Roneker CA, Hu F, Doliba NM, McCormick CCW, Vatamaniuk MZ, Lei XG. Role and mechanism of REG2 depletion in insulin secretion augmented by glutathione peroxidase-1 overproduction. Redox Biol 2022; 56:102457. [PMID: 36063729 PMCID: PMC9463454 DOI: 10.1016/j.redox.2022.102457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/15/2022] [Accepted: 08/24/2022] [Indexed: 11/23/2022] Open
Abstract
We previously reported a depletion of murine regenerating islet-derived protein 2 (REG2) in pancreatic islets of glutathione peroxidase-1 (Gpx1) overexpressing (OE) mice. The present study was to explore if and how the REG2 depletion contributed to an augmented glucose stimulated insulin secretion (GSIS) in OE islets. After we verified a consistent depletion (90%, p < 0.05) of REG2 mRNA, transcript, and protein in OE islets compared with wild-type (WT) controls, we treated cultured and perifused OE islets (70 islets/sample) with REG2 (1 μg/ml or ml · min) and observed 30-40% (p < 0.05) inhibitions of GSIS by REG2. Subsequently, we obtained evidences of co-immunoprecipitation, cell surface ligand binding, and co-immunofluorescence for a ligand-receptor binding between REG2 and transmembrane, L-type voltage-dependent Ca2+ channel (CaV1.2) in beta TC3 cells. Mutating the C-type lectin binding domain of REG2 or deglycosylating CaV1.2 removed the inhibition of REG2 on GSIS and(or) the putative binding between the two proteins. Treating cultured OE and perifused WT islets with REG2 (1 μg/ml or ml · min) decreased (p < 0.05) Ca2+ influx triggered by glucose or KCl. An intraperitoneal (ip) injection of REG2 (2 μg/g) to OE mice (6-month old, n = 10) decreased their plasma insulin concentration (46%, p < 0.05) and elevated their plasma glucose concentration (25%, p < 0.05) over a 60 min period after glucose challenge (ip, 1 g/kg). In conclusion, our study identifies REG2 as a novel regulator of Ca2+ influx and insulin secretion, and reveals a new cascade of GPX1/REG2/CaV1.2 to explain how REG2 depletion in OE islets could decrease its binding to CaV1.2, resulting in uninhibited Ca2+ influx and augmented GSIS. These findings create new links to bridge redox biology, tissue regeneration, and insulin secretion.
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Affiliation(s)
- Xi Yan
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Zeping Zhao
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Jeremy Weaver
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Tao Sun
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Jun-Won Yun
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA; Laboratory of Veterinary Toxicology, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea
| | - Carol A Roneker
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA
| | - Fenghua Hu
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Nicolai M Doliba
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | - Marko Z Vatamaniuk
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
| | - Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, NY, 14853, USA.
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Hagan DW, Ferreira SM, Santos GJ, Phelps EA. The role of GABA in islet function. Front Endocrinol (Lausanne) 2022; 13:972115. [PMID: 36246925 PMCID: PMC9558271 DOI: 10.3389/fendo.2022.972115] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/29/2022] [Indexed: 11/13/2022] Open
Abstract
Gamma aminobutyric acid (GABA) is a non-proteinogenic amino acid and neurotransmitter that is produced in the islet at levels as high as in the brain. GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD), of which the 65 kDa isoform (GAD65) is a major autoantigen in type 1 diabetes. Originally described to be released via synaptic-like microvesicles or from insulin secretory vesicles, beta cells are now understood to release substantial quantities of GABA directly from the cytosol via volume-regulated anion channels (VRAC). Once released, GABA influences the activity of multiple islet cell types through ionotropic GABAA receptors and metabotropic GABAB receptors. GABA also interfaces with cellular metabolism and ATP production via the GABA shunt pathway. Beta cells become depleted of GABA in type 1 diabetes (in remaining beta cells) and type 2 diabetes, suggesting that loss or reduction of islet GABA correlates with diabetes pathogenesis and may contribute to dysfunction of alpha, beta, and delta cells in diabetic individuals. While the function of GABA in the nervous system is well-understood, the description of the islet GABA system is clouded by differing reports describing multiple secretion pathways and effector functions. This review will discuss and attempt to unify the major experimental results from over 40 years of literature characterizing the role of GABA in the islet.
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Affiliation(s)
- D. Walker Hagan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Sandra M. Ferreira
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Gustavo J. Santos
- Islet Biology and Metabolism Lab – I.B.M. Lab, Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina - UFSC, Florianópolis, Brazil
| | - Edward A. Phelps
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
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Liu F, Cai Z, Yang Y, Plasko G, Zhao P, Wu X, Tang C, Li D, Li T, Hu S, Song L, Yu S, Xu R, Luo H, Fan L, Wang E, Xiao Z, Ji Y, Zeng R, Li R, Bai J, Zhou Z, Liu F, Zhang J. The adipocyte-enriched secretory protein tetranectin exacerbates type 2 diabetes by inhibiting insulin secretion from β cells. SCIENCE ADVANCES 2022; 8:eabq1799. [PMID: 36129988 PMCID: PMC9491725 DOI: 10.1126/sciadv.abq1799] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/04/2022] [Indexed: 06/15/2023]
Abstract
Pancreatic β cell failure is a hallmark of diabetes. However, the causes of β cell failure remain incomplete. Here, we report the identification of tetranectin (TN), an adipose tissue-enriched secretory molecule, as a negative regulator of insulin secretion in β cells in diabetes. TN expression is stimulated by high glucose in adipocytes via the p38 MAPK/TXNIP/thioredoxin/OCT4 signaling pathway, and elevated serum TN levels are associated with diabetes. TN treatment greatly exacerbates hyperglycemia in mice and suppresses glucose-stimulated insulin secretion in islets. Conversely, knockout of TN or neutralization of TN function notably improves insulin secretion and glucose tolerance in high-fat diet-fed mice. Mechanistically, TN binds with high selectivity to β cells and inhibits insulin secretion by blocking L-type Ca2+ channels. Our study uncovers an adipocyte-β cell cross-talk that contributes to β cell dysfunction in diabetes and suggests that neutralization of TN levels may provide a new treatment strategy for type 2 diabetes.
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Affiliation(s)
- Fen Liu
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Zixin Cai
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Yan Yang
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - George Plasko
- Department of Pharmacology, University of Texas Health at San Antonio, San Antonio, TX 78229, USA
| | - Piao Zhao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Xiangyue Wu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Dandan Li
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Ting Li
- Department of Liver Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Shanbiao Hu
- Department of Urological Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Lei Song
- Department of Urological Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Shaojie Yu
- Department of Urological Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Ran Xu
- Department of Urology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Hairong Luo
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Libin Fan
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Ersong Wang
- Department of Neurosurgery, Jinshan Hospital, Fudan University, Shanghai 201508, China
| | - Zhen Xiao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yujiao Ji
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Rong Zeng
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Rongxia Li
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Juli Bai
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
- Department of Pharmacology, University of Texas Health at San Antonio, San Antonio, TX 78229, USA
| | - Zhiguang Zhou
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Feng Liu
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Jingjing Zhang
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
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Nagao M, Lagerstedt JO, Eliasson L. Secretory granule exocytosis and its amplification by cAMP in pancreatic β-cells. Diabetol Int 2022; 13:471-479. [PMID: 35694000 PMCID: PMC9174382 DOI: 10.1007/s13340-022-00580-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/17/2022] [Indexed: 10/18/2022]
Abstract
The sequence of events for secreting insulin in response to glucose in pancreatic β-cells is termed "stimulus-secretion coupling". The core of stimulus-secretion coupling is a process which generates electrical activity in response to glucose uptake and causes Ca2+ oscillation for triggering exocytosis of insulin-containing secretory granules. Prior to exocytosis, the secretory granules are mobilized and docked to the plasma membrane and primed for fusion with the plasma membrane. Together with the final fusion with the plasma membrane, these steps are named the exocytosis process of insulin secretion. The steps involved in the exocytosis process are crucial for insulin release from β-cells and considered indispensable for glucose homeostasis. We recently confirmed a signature of defective exocytosis process in human islets and β-cells of obese donors with type 2 diabetes (T2D). Furthermore, cyclic AMP (cAMP) potentiates glucose-stimulated insulin secretion through mechanisms including accelerating the exocytosis process. In this mini-review, we aimed to organize essential knowledge of the secretory granule exocytosis and its amplification by cAMP. Then, we suggest the fatty acid translocase CD36 as a predisposition in β-cells for causing defective exocytosis, which is considered a pathogenesis of T2D in relation to obesity. Finally, we propose potential therapeutics of the defective exocytosis based on a CD36-neutralizing antibody and on Apolipoprotein A-I (ApoA-I), for improving β-cell function in T2D.
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Affiliation(s)
- Mototsugu Nagao
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8603 Japan
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, CRC 91-11, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
| | - Jens O. Lagerstedt
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, CRC 91-11, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
- Novo Nordisk A/S, Copenhagen, Denmark
| | - Lena Eliasson
- Department of Clinical Sciences Malmö, Islet Cell Exocytosis, Lund University Diabetes Centre, Lund University, CRC 91-11, Jan Waldenströms Gata 35, 214 28 Malmö, Sweden
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41
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Harvey KE, LaVigne EK, Dar MS, Salyer AE, Pratt EPS, Sample PA, Aryal UK, Gowher H, Hockerman GH. RyR2/IRBIT regulates insulin gene transcript, insulin content, and secretion in the insulinoma cell line INS-1. Sci Rep 2022; 12:7713. [PMID: 35562179 PMCID: PMC9095623 DOI: 10.1038/s41598-022-11276-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/31/2022] [Indexed: 12/01/2022] Open
Abstract
The role of ER Ca2+ release via ryanodine receptors (RyR) in pancreatic β-cell function is not well defined. Deletion of RyR2 from the rat insulinoma INS-1 (RyR2KO) enhanced IP3 receptor activity stimulated by 7.5 mM glucose, coincident with reduced levels of the protein IP3 Receptor Binding protein released with Inositol 1,4,5 Trisphosphate (IRBIT). Insulin content, basal (2.5 mM glucose) and 7.5 mM glucose-stimulated insulin secretion were reduced in RyR2KO and IRBITKO cells compared to controls. INS2 mRNA levels were reduced in both RyR2KO and IRBITKO cells, but INS1 mRNA levels were specifically decreased in RyR2KO cells. Nuclear localization of S-adenosylhomocysteinase (AHCY) was increased in RyR2KO and IRBITKO cells. DNA methylation of the INS1 and INS2 gene promotor regions was very low, and not different among RyR2KO, IRBITKO, and controls, but exon 2 of the INS1 and INS2 genes was more extensively methylated in RyR2KO and IRBITKO cells. Exploratory proteomic analysis revealed that deletion of RyR2 or IRBIT resulted in differential regulation of 314 and 137 proteins, respectively, with 41 in common. These results suggest that RyR2 regulates IRBIT levels and activity in INS-1 cells, and together maintain insulin content and secretion, and regulate the proteome, perhaps via DNA methylation.
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Affiliation(s)
- Kyle E Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Emily K LaVigne
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
- Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, IN, USA
| | - Mohd Saleem Dar
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
| | - Amy E Salyer
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Evan P S Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
- Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, IN, USA
| | - Paxton A Sample
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Uma K Aryal
- Proteomics Facility, Bindley Bioscience Center, Purdue University, West Lafayette, IN, USA
| | - Humaira Gowher
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
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Al-Abdulla R, Ferrero H, Soriano S, Boronat-Belda T, Alonso-Magdalena P. Screening of Relevant Metabolism-Disrupting Chemicals on Pancreatic β-Cells: Evaluation of Murine and Human In Vitro Models. Int J Mol Sci 2022; 23:ijms23084182. [PMID: 35457000 PMCID: PMC9025712 DOI: 10.3390/ijms23084182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 02/01/2023] Open
Abstract
Endocrine-disrupting chemicals (EDCs) are chemical substances that can interfere with the normal function of the endocrine system. EDCs are ubiquitous and can be found in a variety of consumer products such as food packaging materials, personal care and household products, plastic additives, and flame retardants. Over the last decade, the impact of EDCs on human health has been widely acknowledged as they have been associated with different endocrine diseases. Among them, a subset called metabolism-disrupting chemicals (MDCs) is able to promote metabolic changes that can lead to the development of metabolic disorders such as diabetes, obesity, hepatic steatosis, and metabolic syndrome, among others. Despite this, today, there are still no definitive and standardized in vitro tools to support the metabolic risk assessment of existing and emerging MDCs for regulatory purposes. Here, we evaluated the following two different pancreatic cell-based in vitro systems: the murine pancreatic β-cell line MIN6 as well as the human pancreatic β-cell line EndoC-βH1. Both were challenged with the following range of relevant concentrations of seven well-known EDCs: (bisphenol-A (BPA), bisphenol-S (BPS), bisphenol-F (BPF), perfluorooctanesulfonic acid (PFOS), di(2-ethylhexyl) phthalate (DEHP), cadmium chloride (CdCl2), and dichlorodiphenyldichloroethylene (DDE)). The screening revealed that most of the tested chemicals have detectable, deleterious effects on glucose-stimulated insulin release, insulin content, electrical activity, gene expression, and/or viability. Our data provide new molecular information on the direct effects of the selected chemicals on key aspects of pancreatic β-cell function, such as the stimulus-secretion coupling and ion channel activity. In addition, we found that, in general, the sensitivity and responses were comparable to those from other in vivo studies reported in the literature. Overall, our results suggest that both systems can serve as effective tools for the rapid screening of potential MDC effects on pancreatic β-cell physiology as well as for deciphering and better understanding the molecular mechanisms that underlie their action.
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Affiliation(s)
- Ruba Al-Abdulla
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, 03202 Elche, Spain; (R.A.-A.); (H.F.); (S.S.); (T.B.-B.)
| | - Hilda Ferrero
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, 03202 Elche, Spain; (R.A.-A.); (H.F.); (S.S.); (T.B.-B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Sergi Soriano
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, 03202 Elche, Spain; (R.A.-A.); (H.F.); (S.S.); (T.B.-B.)
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, 03690 Alicante, Spain
| | - Talía Boronat-Belda
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, 03202 Elche, Spain; (R.A.-A.); (H.F.); (S.S.); (T.B.-B.)
| | - Paloma Alonso-Magdalena
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, 03202 Elche, Spain; (R.A.-A.); (H.F.); (S.S.); (T.B.-B.)
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
- Correspondence:
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43
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Guérineau NC, Campos P, Le Tissier PR, Hodson DJ, Mollard P. Cell Networks in Endocrine/Neuroendocrine Gland Function. Compr Physiol 2022; 12:3371-3415. [PMID: 35578964 DOI: 10.1002/cphy.c210031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Reproduction, growth, stress, and metabolism are determined by endocrine/neuroendocrine systems that regulate circulating hormone concentrations. All these systems generate rhythms and changes in hormone pulsatility observed in a variety of pathophysiological states. Thus, the output of endocrine/neuroendocrine systems must be regulated within a narrow window of effective hormone concentrations but must also maintain a capacity for plasticity to respond to changing physiological demands. Remarkably most endocrinologists still have a "textbook" view of endocrine gland organization which has emanated from 20th century histological studies on thin 2D tissue sections. However, 21st -century technological advances, including in-depth 3D imaging of specific cell types have vastly changed our knowledge. We now know that various levels of multicellular organization can be found across different glands, that organizational motifs can vary between species and can be modified to enhance or decrease hormonal release. This article focuses on how the organization of cells regulates hormone output using three endocrine/neuroendocrine glands that present different levels of organization and complexity: the adrenal medulla, with a single neuroendocrine cell type; the anterior pituitary, with multiple intermingled cell types; and the pancreas with multiple intermingled cell types organized into distinct functional units. We give an overview of recent methodologies that allow the study of the different components within endocrine systems, particularly their temporal and spatial relationships. We believe the emerging findings about network organization, and its impact on hormone secretion, are crucial to understanding how homeostatic regulation of endocrine axes is carried out within endocrine organs themselves. © 2022 American Physiological Society. Compr Physiol 12:3371-3415, 2022.
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Affiliation(s)
| | - Pauline Campos
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Paul R Le Tissier
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Edgbaston, UK.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK.,COMPARE University of Birmingham and University of Nottingham Midlands, UK.,Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Patrice Mollard
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
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44
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Lubberding AF, Juhl CR, Skovhøj EZ, Kanters JK, Mandrup‐Poulsen T, Torekov SS. Celebrities in the heart, strangers in the pancreatic beta cell: Voltage-gated potassium channels K v 7.1 and K v 11.1 bridge long QT syndrome with hyperinsulinaemia as well as type 2 diabetes. Acta Physiol (Oxf) 2022; 234:e13781. [PMID: 34990074 PMCID: PMC9286829 DOI: 10.1111/apha.13781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/20/2021] [Accepted: 01/02/2022] [Indexed: 12/13/2022]
Abstract
Voltage‐gated potassium (Kv) channels play an important role in the repolarization of a variety of excitable tissues, including in the cardiomyocyte and the pancreatic beta cell. Recently, individuals carrying loss‐of‐function (LoF) mutations in KCNQ1, encoding Kv7.1, and KCNH2 (hERG), encoding Kv11.1, were found to exhibit post‐prandial hyperinsulinaemia and episodes of hypoglycaemia. These LoF mutations also cause the cardiac disorder long QT syndrome (LQTS), which can be aggravated by hypoglycaemia. Interestingly, patients with LQTS also have a higher burden of diabetes compared to the background population, an apparent paradox in relation to the hyperinsulinaemic phenotype, and KCNQ1 has been identified as a type 2 diabetes risk gene. This review article summarizes the involvement of delayed rectifier K+ channels in pancreatic beta cell function, with emphasis on Kv7.1 and Kv11.1, using the cardiomyocyte for context. The functional and clinical consequences of LoF mutations and polymorphisms in these channels on blood glucose homeostasis are explored using evidence from pre‐clinical, clinical and genome‐wide association studies, thereby evaluating the link between LQTS, hyperinsulinaemia and type 2 diabetes.
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Affiliation(s)
- Anniek F. Lubberding
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Christian R. Juhl
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Emil Z. Skovhøj
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Jørgen K. Kanters
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Thomas Mandrup‐Poulsen
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Signe S. Torekov
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
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45
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Dai XQ, Camunas-Soler J, Briant LJB, Dos Santos T, Spigelman AF, Walker EM, Arrojo E Drigo R, Bautista A, Jones RC, Avrahami D, Lyon J, Nie A, Smith N, Zhang Y, Johnson J, Manning Fox JE, Michelakis ED, Light PE, Kaestner KH, Kim SK, Rorsman P, Stein RW, Quake SR, MacDonald PE. Heterogenous impairment of α cell function in type 2 diabetes is linked to cell maturation state. Cell Metab 2022; 34:256-268.e5. [PMID: 35108513 PMCID: PMC8852281 DOI: 10.1016/j.cmet.2021.12.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/08/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023]
Abstract
In diabetes, glucagon secretion from pancreatic α cells is dysregulated. The underlying mechanisms, and whether dysfunction occurs uniformly among cells, remain unclear. We examined α cells from human donors and mice using electrophysiological, transcriptomic, and computational approaches. Rising glucose suppresses α cell exocytosis by reducing P/Q-type Ca2+ channel activity, and this is disrupted in type 2 diabetes (T2D). Upon high-fat feeding of mice, α cells shift toward a "β cell-like" electrophysiological profile in concert with indications of impaired identity. In human α cells we identified links between cell membrane properties and cell surface signaling receptors, mitochondrial respiratory chain complex assembly, and cell maturation. Cell-type classification using machine learning of electrophysiology data demonstrated a heterogenous loss of "electrophysiologic identity" in α cells from donors with type 2 diabetes. Indeed, a subset of α cells with impaired exocytosis is defined by an enrichment in progenitor and lineage markers and upregulation of an immature transcriptomic phenotype, suggesting important links between α cell maturation state and dysfunction.
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Affiliation(s)
- Xiao-Qing Dai
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Joan Camunas-Soler
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94518, USA
| | - Linford J B Briant
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Churchill Hospital, Oxford OX3 7LE, UK
| | - Theodore Dos Santos
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Aliya F Spigelman
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Emily M Walker
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48105, USA
| | - Rafael Arrojo E Drigo
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Austin Bautista
- Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Robert C Jones
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Dana Avrahami
- Endocrinology and Metabolism Department, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel
| | - James Lyon
- Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Aifang Nie
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Nancy Smith
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Yongneng Zhang
- Department of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Janyne Johnson
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Jocelyn E Manning Fox
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | | | - Peter E Light
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Stanford Diabetes Research Center, Stanford University, Stanford, CA 94305, USA
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Churchill Hospital, Oxford OX3 7LE, UK
| | - Roland W Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94518, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Patrick E MacDonald
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada.
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46
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Budnik B, Straubhaar J, Neveu J, Shvartsman D. In‐depth analysis of proteomic and genomic fluctuations during the time course of human embryonic stem cells directed differentiation into beta cells. Proteomics 2022; 22:e2100265. [DOI: 10.1002/pmic.202100265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Bogdan Budnik
- Mass Spectrometry and Proteomics Resource Laboratory (MSPRL) FAS Division of Science Harvard University 52 Oxford Street Cambridge MA 02138 USA
| | - Juerg Straubhaar
- Informatics and Scientific Applications Group FAS Center for Systems Biology Harvard University 38 Oxford Street Cambridge MA 02138 USA
| | - John Neveu
- Mass Spectrometry and Proteomics Resource Laboratory (MSPRL) FAS Division of Science Harvard University 52 Oxford Street Cambridge MA 02138 USA
| | - Dmitry Shvartsman
- Department of Stem Cell and Regenerative Biology Harvard Stem Cell Institute Harvard University 7 Divinity Avenue Cambridge MA 02138 USA
- Present address: Cellaria Inc. 9 Audubon Road Wakefield MA 01880 USA
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47
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Membrane polarization in non-neuronal cells as a potential mechanism of metabolic disruption by depolarizing insecticides. Food Chem Toxicol 2022; 160:112804. [PMID: 34990786 DOI: 10.1016/j.fct.2021.112804] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/22/2021] [Accepted: 12/31/2021] [Indexed: 01/01/2023]
Abstract
A significant rise in the incidence of obesity and type 2 diabetes has occurred worldwide in the last two decades. Concurrently, a growing body of evidence suggests a connection between exposure to environmental pollutants, particularly insecticides, and the development of obesity and type 2 diabetes. This review summarizes key evidence of (1) the presence of different types of neuronal receptors - target sites for neurotoxic insecticides - in non-neuronal cells, (2) the activation of these receptors in non-neuronal cells by membrane-depolarizing insecticides, and (3) changes in metabolic functions, including lipid and glucose accumulation, associated with changes in membrane potential. Based on these findings, we propose that changes in membrane potential (Vmem) by certain insecticides serve as a novel regulator of lipid and glucose metabolism in non-excitable cells associated with obesity and type 2 diabetes.
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48
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Sancho M, Kyle BD. The Large-Conductance, Calcium-Activated Potassium Channel: A Big Key Regulator of Cell Physiology. Front Physiol 2021; 12:750615. [PMID: 34744788 PMCID: PMC8567177 DOI: 10.3389/fphys.2021.750615] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/29/2021] [Indexed: 12/01/2022] Open
Abstract
Large-conductance Ca2+-activated K+ channels facilitate the efflux of K+ ions from a variety of cells and tissues following channel activation. It is now recognized that BK channels undergo a wide range of pre- and post-translational modifications that can dramatically alter their properties and function. This has downstream consequences in affecting cell and tissue excitability, and therefore, function. While finding the “silver bullet” in terms of clinical therapy has remained elusive, ongoing research is providing an impressive range of viable candidate proteins and mechanisms that associate with and modulate BK channel activity, respectively. Here, we provide the hallmarks of BK channel structure and function generally, and discuss important milestones in the efforts to further elucidate the diverse properties of BK channels in its many forms.
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Affiliation(s)
- Maria Sancho
- Department of Pharmacology, University of Vermont, Burlington, VT, United States
| | - Barry D Kyle
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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49
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Liu T, Cui L, Xue H, Yang X, Liu M, Zhi L, Yang H, Liu Z, Zhang M, Guo Q, He P, Liu Y, Zhang Y. Telmisartan Potentiates Insulin Secretion via Ion Channels, Independent of the AT1 Receptor and PPARγ. Front Pharmacol 2021; 12:739637. [PMID: 34594226 PMCID: PMC8477257 DOI: 10.3389/fphar.2021.739637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/30/2021] [Indexed: 01/15/2023] Open
Abstract
Angiotensin II type 1 (AT1) receptor blockers (ARBs), as antihypertensive drugs, have drawn attention for their benefits to individuals with diabetes and prediabetes. However, the direct effects of ARBs on insulin secretion remain unclear. In this study, we aimed to investigate the insulinotropic effect of ARBs and the underlying electrophysiological mechanism. We found that only telmisartan among the three ARBs (telmisartan, valsartan, and irbesartan) exhibited an insulin secretagogue role in rat islets. Independent of AT1 receptor and peroxisome proliferator-activated receptor γ (PPARγ), telmisartan exerted effects on ion channels including voltage-dependent potassium (Kv) channels and L-type voltage-gated calcium channels (VGCCs) to promote extracellular Ca2+ influx, thereby potentiating insulin secretion in a glucose-dependent manner. Furthermore, we identified that telmisartan directly inhibited Kv2.1 channel on a Chinese hamster ovary cell line with Kv2.1 channel overexpression. Acute exposure of db/db mice to a telmisartan dose equivalent to therapeutic doses in humans resulted in lower blood glucose and increased plasma insulin concentration in OGTT. We further observed the telmisartan-induced insulinotropic and electrophysiological effects on pathological pancreatic islets or β-cells isolated from db/db mice. Collectively, our results establish an important insulinotropic function of telmisartan distinct from other ARBs in the treatment of diabetes.
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Affiliation(s)
- Tao Liu
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China.,Department of General Surgery, Shanxi Bethune Hospital (Third Hospital of Shanxi Medical University), Taiyuan, China
| | - Lijuan Cui
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Huan Xue
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Xiaohua Yang
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Mengmeng Liu
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Linping Zhi
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Huanhuan Yang
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Zhihong Liu
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
| | - Min Zhang
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Qing Guo
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China
| | - Peifeng He
- School of Management, Shanxi Medical University, Taiyuan, China
| | - Yunfeng Liu
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Yi Zhang
- Department of Pharmacology, School of Basic Medicine, Shanxi Medical University, Taiyuan, China.,Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, China
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50
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Sodium background currents in endocrine/neuroendocrine cells: Towards unraveling channel identity and contribution in hormone secretion. Front Neuroendocrinol 2021; 63:100947. [PMID: 34592201 DOI: 10.1016/j.yfrne.2021.100947] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/03/2021] [Accepted: 09/23/2021] [Indexed: 02/04/2023]
Abstract
In endocrine/neuroendocrine tissues, excitability of secretory cells is patterned by the repertoire of ion channels and there is clear evidence that extracellular sodium (Na+) ions contribute to hormone secretion. While voltage-gated channels involved in action potential generation are well-described, the background 'leak' channels operating near the resting membrane potential are much less known, and in particular the channels supporting a background entry of Na+ ions. These background Na+ currents (called here 'INab') have the ability to modulate the resting membrane potential and subsequently affect action potential firing. Here we compile and analyze the data collected from three endocrine/neuroendocrine tissues: the anterior pituitary gland, the adrenal medulla and the endocrine pancreas. We also model how INab can be functionally involved in cellular excitability. Finally, towards deciphering the physiological role of INab in endocrine/neuroendocrine cells, its implication in hormone release is also discussed.
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