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Wang L, Zhang J, Li W, Zhang X, Yokoyama T, Sakamoto M, Wang Y. The A-kinase anchoring protein Yotiao decrease the ER calcium content by inhibiting the store operated calcium entry. Cell Calcium 2024; 121:102906. [PMID: 38781694 DOI: 10.1016/j.ceca.2024.102906] [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: 02/08/2024] [Revised: 05/10/2024] [Accepted: 05/10/2024] [Indexed: 05/25/2024]
Abstract
The meticulous regulation of ER calcium (Ca2+) homeostasis is indispensable for the proper functioning of numerous cellular processes. Disrupted ER Ca2+ balance is implicated in diverse diseases, underscoring the need for a systematic exploration of its regulatory factors in cells. Our recent genomic-scale screen identified a scaffolding protein A-kinase anchoring protein 9 (AKAP9) as a regulator of ER Ca2+ levels, but the underlying molecular mechanisms remain elusive. Here, we reveal that Yotiao, the smallest splicing variant of AKAP9 decreased ER Ca2+ content in animal cells. Additional testing using a combination of Yotiao truncations, knock-out cells and pharmacological tools revealed that, Yotiao does not require most of its interactors, including type 1 inositol 1,4,5-trisphosphate receptors (IP3R1), protein kinase A (PKA), protein phosphatase 1 (PP1), adenylyl cyclase type 2 (AC2) and so on, to reduce ER Ca2+ levels. However, adenylyl cyclase type 9 (AC9), which is known to increases its cAMP generation upon interaction with Yotiao for the modulation of potassium channels, plays an essential role for Yotiao's ER-Ca2+-lowering effect. Mechanistically, Yotiao may work through AC9 to act on Orai1-C terminus and suppress store operated Ca2+ entry, resulting in reduced ER Ca2+ levels. These findings not only enhance our comprehension of the interplay between Yotiao and AC9 but also contribute to a more intricate understanding of the finely tuned mechanisms governing ER Ca2+ homeostasis.
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Affiliation(s)
- Liuqing Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Jiaxuan Zhang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Wanjie Li
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Xiaoyan Zhang
- Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Tatsushi Yokoyama
- Department of Optical Neural and Molecular Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Masayuki Sakamoto
- Department of Optical Neural and Molecular Physiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Youjun Wang
- Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, China; Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, China.
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2
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Tamarit-Rodriguez J. Regulatory Role of Fatty Acid Metabolism on Glucose-Induced Changes in Insulin and Glucagon Secretion by Pancreatic Islet Cells. Int J Mol Sci 2024; 25:6052. [PMID: 38892240 PMCID: PMC11172437 DOI: 10.3390/ijms25116052] [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: 04/17/2024] [Revised: 05/21/2024] [Accepted: 05/26/2024] [Indexed: 06/21/2024] Open
Abstract
A detailed study of palmitate metabolism in pancreatic islets subject to different experimental conditions, like varying concentrations of glucose, as well as fed or starved conditions, has allowed us to explore the interaction between the two main plasma nutrients and its consequences on hormone secretion. Palmitate potentiates glucose-induced insulin secretion in a concentration-dependent manner, in a physiological range of both palmitate (0-2 mM) and glucose (6-20 mM) concentrations; at glucose concentrations lower than 6 mM, no metabolic interaction with palmitate was apparent. Starvation (48 h) increased islet palmitate oxidation two-fold, and the effect was resistant to its inhibition by glucose (6-20 mM). Consequently, labelled palmitate and glucose incorporation into complex lipids were strongly suppressed, as well as glucose-induced insulin secretion and its potentiation by palmitate. 2-bromostearate, a palmitate oxidation inhibitor, fully recovered the synthesis of complex lipids and insulin secretion. We concluded that palmitate potentiation of the insulin response to glucose is not attributable to its catabolic mitochondrial oxidation but to its anabolism to complex lipids: islet lipid biosynthesis is dependent on the uptake of plasma fatty acids and the supply of α-glycerol phosphate from glycolysis. Islet secretion of glucagon and somatostatin showed a similar dependence on palmitate anabolism as insulin. The possible mechanisms implicated in the metabolic coupling between glucose and palmitate were commented on. Moreover, possible mechanisms responsible for islet gluco- or lipotoxicity after a long-term stimulation of insulin secretion were also discussed. Our own data on the simultaneous stimulation of insulin, glucagon, and somatostatin by glucose, as well as their modification by 2-bromostearate in perifused rat islets, give support to the conclusion that increased FFA anabolism, rather than its mitochondrial oxidation, results in a potentiation of their stimulated release. Starvation, besides suppressing glucose stimulation of insulin secretion, also blocks the inhibitory effect of glucose on glucagon secretion: this suggests that glucagon inhibition might be an indirect or direct effect of insulin, but not of glucose. In summary, there seems to exist three mechanisms of glucagon secretion stimulation: 1. glucagon stimulation through the same secretion coupling mechanism as insulin, but in a different range of glucose concentrations (0 to 5 mM). 2. Direct or indirect inhibition by secreted insulin in response to glucose (5-20 mM). 3. Stimulation by increased FFA anabolism in glucose intolerance or diabetes in the context of hyperlipidemia, hyperglycemia, and hypo-insulinemia. These conclusions were discussed and compared with previous published data in the literature. Specially, we discussed the mechanism for inhibition of glucagon release by glucose, which was apparently contradictory with the secretion coupling mechanism of its stimulation.
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Dobson JR, Jacobson DA. Disrupted Endoplasmic Reticulum Ca 2+ Handling: A Harβinger of β-Cell Failure. BIOLOGY 2024; 13:379. [PMID: 38927260 PMCID: PMC11200644 DOI: 10.3390/biology13060379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 06/28/2024]
Abstract
The β-cell workload increases in the setting of insulin resistance and reduced β-cell mass, which occurs in type 2 and type 1 diabetes, respectively. The prolonged elevation of insulin production and secretion during the pathogenesis of diabetes results in β-cell ER stress. The depletion of β-cell Ca2+ER during ER stress activates the unfolded protein response, leading to β-cell dysfunction. Ca2+ER is involved in many pathways that are critical to β-cell function, such as protein processing, tuning organelle and cytosolic Ca2+ handling, and modulating lipid homeostasis. Mutations that promote β-cell ER stress and deplete Ca2+ER stores are associated with or cause diabetes (e.g., mutations in ryanodine receptors and insulin). Thus, improving β-cell Ca2+ER handling and reducing ER stress under diabetogenic conditions could preserve β-cell function and delay or prevent the onset of diabetes. This review focuses on how mechanisms that control β-cell Ca2+ER are perturbed during the pathogenesis of diabetes and contribute to β-cell failure.
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Affiliation(s)
| | - David A. Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA;
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Hu Y, Tian C, Chen F, Zhang A, Wang W. The mystery of methylmercury-perturbed calcium homeostasis: AMPK-DRP1-dependent mitochondrial fission initiates ER-mitochondria contact formation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171398. [PMID: 38442753 DOI: 10.1016/j.scitotenv.2024.171398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/17/2024] [Accepted: 02/28/2024] [Indexed: 03/07/2024]
Abstract
Methylmercury (MeHg), as a global environmental pollutant, is of concern globally due to its neurodevelopmental toxicity. Mitochondria-associated membranes (MAMs) are highly dynamic sites of endoplasmic reticulum (ER)-haemocyte contact. MAMs are closely associated with the pathophysiology of neurological disorders due to their role in the transfer of calcium ions (Ca2+) between mitochondria and the ER. However, the molecular mechanisms that control these interactions in MeHg-induced neurotoxicity have not yet been characterized. In the current study, MeHg caused increases in the levels of both cytosolic and mitochondrial Ca2+ in PC12 cells and promoted MAMs formation in both in vivo and in vitro experiments. Of note, MeHg perturbed mitochondrial dynamics, promoting a shift toward a fission phenotype, and this was supported by the dysregulation of fission regulators. Interestingly, the MeHg-induced promotion of MAMs formation and increase in Ca2+ levels were effectively attenuated by the inhibition of mitochondrial fission using Mdivi-1, a DRP1 inhibitor. Furthermore, MeHg triggered the AMPK pathway, and most of the aforementioned changes were significantly rescued by Compound C. Mechanistic investigations revealed a reciprocal relationship between AMPK- and Ca2+-mediated mitochondrial fission. The specific inhibitor of Ca2+ uniporter, ruthenium-red (RuR), effectively abolished the feedback regulation of mitochondrial dynamics and MAMs formation mediated by AMPK in response to MeHg-induced Ca2+ overload. This study reveals a novel role of AMPK-DRP1-mediated mitochondrial fragmentation in the coupling of ER-mitochondrial calcium microdomains in MeHg-induced neurotoxicity. The findings provide valuable insights for the development of strategies to regulate mitochondrial imbalances in neurological diseases.
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Affiliation(s)
- Yi Hu
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Changsong Tian
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Fang Chen
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Aihua Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Wenjuan Wang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; Key Laboratory of Human Brain bank for Functions and Diseases of Department of Education of Guizhou Province, Guizhou Medical University, Guiyang 550025, China.
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5
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Elwakiel A, Mathew A, Isermann B. The role of endoplasmic reticulum-mitochondria-associated membranes in diabetic kidney disease. Cardiovasc Res 2024; 119:2875-2883. [PMID: 38367274 DOI: 10.1093/cvr/cvad190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/03/2023] [Accepted: 07/07/2023] [Indexed: 02/19/2024] Open
Abstract
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease worldwide. The pathomechanisms of DKD are multifactorial, yet haemodynamic and metabolic changes in the early stages of the disease appear to predispose towards irreversible functional loss and histopathological changes. Recent studies highlight the importance of endoplasmic reticulum-mitochondria-associated membranes (ER-MAMs), structures conveying important cellular homeostatic and metabolic effects, in the pathology of DKD. Disruption of ER-MAM integrity in diabetic kidneys is associated with DKD progression, but the regulation of ER-MAMs and their pathogenic contribution remain largely unknown. Exploring the cell-specific components and dynamic changes of ER-MAMs in diabetic kidneys may lead to the identification of new approaches to detect and stratify diabetic patients with DKD. In addition, these insights may lead to novel therapeutic approaches to target and/or reverse disease progression. In this review, we discuss the association of ER-MAMs with key pathomechanisms driving DKD such as insulin resistance, dyslipidaemia, ER stress, and inflammasome activation and the importance of further exploration of ER-MAMs as diagnostic and therapeutic targets in DKD.
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Affiliation(s)
- Ahmed Elwakiel
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
| | - Akash Mathew
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
| | - Berend Isermann
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, Paul-List-Straße 13/15, 04103 Leipzig, Germany
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Motomura K, Matsuzaka T, Shichino S, Ogawa T, Pan H, Nakajima T, Asano Y, Okayama T, Takeuchi T, Ohno H, Han SI, Miyamoto T, Takeuchi Y, Sekiya M, Sone H, Yahagi N, Nakagawa Y, Oda T, Ueha S, Ikeo K, Ogura A, Matsushima K, Shimano H. Single-Cell Transcriptome Profiling of Pancreatic Islets From Early Diabetic Mice Identifies Anxa10 for Ca2+ Allostasis Toward β-Cell Failure. Diabetes 2024; 73:75-92. [PMID: 37871012 PMCID: PMC10784657 DOI: 10.2337/db23-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 10/10/2023] [Indexed: 10/25/2023]
Abstract
Type 2 diabetes is a progressive disorder denoted by hyperglycemia and impaired insulin secretion. Although a decrease in β-cell function and mass is a well-known trigger for diabetes, the comprehensive mechanism is still unidentified. Here, we performed single-cell RNA sequencing of pancreatic islets from prediabetic and diabetic db/db mice, an animal model of type 2 diabetes. We discovered a diabetes-specific transcriptome landscape of endocrine and nonendocrine cell types with subpopulations of β- and α-cells. We recognized a new prediabetic gene, Anxa10, that was induced by and regulated Ca2+ influx from metabolic stresses. Anxa10-overexpressed β-cells displayed suppression of glucose-stimulated intracellular Ca2+ elevation and potassium-induced insulin secretion. Pseudotime analysis of β-cells predicted that this Ca2+-surge responder cluster would proceed to mitochondria dysfunction and endoplasmic reticulum stress. Other trajectories comprised dedifferentiation and transdifferentiation, emphasizing acinar-like cells in diabetic islets. Altogether, our data provide a new insight into Ca2+ allostasis and β-cell failure processes. ARTICLE HIGHLIGHTS The transcriptome of single-islet cells from healthy, prediabetic, and diabetic mice was studied. Distinct β-cell heterogeneity and islet cell-cell network in prediabetes and diabetes were found. A new prediabetic β-cell marker, Anxa10, regulates intracellular Ca2+ and insulin secretion. Diabetes triggers β-cell to acinar cell transdifferentiation.
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Affiliation(s)
- Kaori Motomura
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Takashi Matsuzaka
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Transborder Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shigeyuki Shichino
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Tatsuro Ogawa
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Hao Pan
- Department of Bio-Science, Nagahama Institute of BioScience and Technology, Nagahama, Shiga, Japan
| | - Takuya Nakajima
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Yasuhito Asano
- Faculty of Information Networking for Innovation and Design, Toyo University, Tokyo, Japan
| | - Toshitsugu Okayama
- Center for Information Biology, National Institute of Genetics, Mishima, Japan
| | - Tomoyo Takeuchi
- Tsukuba Human Tissue Biobank Center, University of Tsukuba Hospital, Ibaraki, Japan
| | - Hiroshi Ohno
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Song-iee Han
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Takafumi Miyamoto
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshinori Takeuchi
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Motohiro Sekiya
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hirohito Sone
- Department of Hematology, Endocrinology and Metabolism, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Naoya Yahagi
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshimi Nakagawa
- Division of Complex Biosystem Research, Department of Research and Development, Institute of Natural Medicine, University of Toyama, Toyama, Japan
| | - Tatsuya Oda
- Department of Gastrointestinal and Hepatobiliary Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Satoshi Ueha
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Kazuho Ikeo
- Center for Information Biology, National Institute of Genetics, Mishima, Japan
| | - Atsushi Ogura
- Department of Bio-Science, Nagahama Institute of BioScience and Technology, Nagahama, Shiga, Japan
| | - Kouji Matsushima
- Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute of Biomedical Sciences, Tokyo University of Science, Noda, Japan
| | - Hitoshi Shimano
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, Japan
- Life Science Center of Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Perrier J, Nawrot M, Madec AM, Chikh K, Chauvin MA, Damblon C, Sabatier J, Thivolet CH, Rieusset J, Rautureau GJP, Panthu B. Human Pancreatic Islets React to Glucolipotoxicity by Secreting Pyruvate and Citrate. Nutrients 2023; 15:4791. [PMID: 38004183 PMCID: PMC10674605 DOI: 10.3390/nu15224791] [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: 09/27/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Progressive decline in pancreatic beta-cell function is central to the pathogenesis of type 2 diabetes (T2D). Here, we explore the relationship between the beta cell and its nutritional environment, asking how an excess of energy substrate leads to altered energy production and subsequent insulin secretion. Alterations in intracellular metabolic homeostasis are key markers of islets with T2D, but changes in cellular metabolite exchanges with their environment remain unknown. We answered this question using nuclear magnetic resonance-based quantitative metabolomics and evaluated the consumption or secretion of 31 extracellular metabolites from healthy and T2D human islets. Islets were also cultured under high levels of glucose and/or palmitate to induce gluco-, lipo-, and glucolipotoxicity. Biochemical analyses revealed drastic alterations in the pyruvate and citrate pathways, which appear to be associated with mitochondrial oxoglutarate dehydrogenase (OGDH) downregulation. We repeated these manipulations on the rat insulinoma-derived beta-pancreatic cell line (INS-1E). Our results highlight an OGDH downregulation with a clear effect on the pyruvate and citrate pathways. However, citrate is directed to lipogenesis in the INS-1E cells instead of being secreted as in human islets. Our results demonstrate the ability of metabolomic approaches performed on culture media to easily discriminate T2D from healthy and functional islets.
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Affiliation(s)
- Johan Perrier
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
| | - Margaux Nawrot
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
| | - Anne-Marie Madec
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
| | - Karim Chikh
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
- Department of Endocrinology and Diabetes, Hospices Civils de Lyon, Hopital Lyon Sud, 69310 Pierre-Bénite, France
| | - Marie-Agnès Chauvin
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
| | - Christian Damblon
- Unité de Recherche MolSys, Faculté des Sciences, Université de Liège, 99131 Liège, Belgium
| | - Julia Sabatier
- Laboratory of Cell Therapy for Diabetes (LTCD), PRIMS Facility, Institute for Regenerative Medicine and Biotherapy (IRMB), University Hospital of Montpellier, 34295 Montpellier, France
| | - Charles H. Thivolet
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
- Department of Endocrinology and Diabetes, Hospices Civils de Lyon, Hopital Lyon Sud, 69310 Pierre-Bénite, France
| | - Jennifer Rieusset
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
| | - Gilles J. P. Rautureau
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs, UMR 5082 CNRS, ENS Lyon, UCBL, Université de Lyon, 69100 Villeurbanne, France
| | - Baptiste Panthu
- Laboratoire CarMeN, UMR INSERM U1060/INRAE U1397, University of Lyon, Université Claude Bernard Lyon 1, 69310 Pierre-Bénite, France
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Nguyen HT, Noriega Polo C, Wiederkehr A, Wollheim CB, Park KS. CDN1163, an activator of sarco/endoplasmic reticulum Ca 2+ ATPase, up-regulates mitochondrial functions and protects against lipotoxicity in pancreatic β-cells. Br J Pharmacol 2023; 180:2762-2776. [PMID: 37277321 DOI: 10.1111/bph.16160] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 06/07/2023] Open
Abstract
BACKGROUND AND PURPOSE High levels of Ca2+ in the endoplasmic reticulum (ER), established by the sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), are required for protein folding and cell signalling. Excessive ER Ca2+ release or decreased SERCA activity induces unfolded protein accumulation and ER stress in pancreatic β-cells, leading to defective insulin secretion and diabetes. Here we have investigated the consequences of enhancing ER Ca2+ uptake on β-cell survival and function. EXPERIMENTAL APPROACH The effects of SERCA activator, CDN1163, on Ca2+ homeostasis, protein expression, mitochondrial activities, insulin secretion, and lipotoxicity have been studied in mouse pancreatic β-cells and MIN6 cells. KEY RESULTS CDN1163, increased insulin synthesis and exocytosis from islets. CDN1163 also increased the sensitivity of the cytosolic Ca2+ oscillation response to glucose and potentiated it in dispersed and sorted β-cells. CDN1163 augmented the ER and mitochondrial Ca2+ content, the mitochondrial membrane potential, respiration, and ATP synthesis. CDN1163 up-regulated expression of inositol 1,4,5-trisphosphate receptors and antioxidant enzymes, and mitochondrial biogenesis, including peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α). Overexpression of SERCA2a or 2b replicated the effects of CDN1163, while knockdown of SERCA2 abolished the stimulatory actions of CDN1163. In palmitate-treated β-cells, CDN1163 prevented ER Ca2+ depletion, mitochondrial dysfunction, cytosolic and mitochondrial oxidative stress, defective insulin secretion, and apoptotic cell death. CONCLUSIONS AND IMPLICATIONS Activation of SERCA enhanced mitochondrial bioenergetics and antioxidant capability, suppressing the cytotoxic effects of palmitate. Our results suggest that targeting SERCA could be a novel therapeutic strategy to protect β-cells from lipotoxicity and the development of Type 2 diabetes.
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Affiliation(s)
- Ha Thu Nguyen
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Carlos Noriega Polo
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | | | - Claes B Wollheim
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
- Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, South Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, South Korea
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9
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He Q, Qu M, Shen T, Su J, Xu Y, Xu C, Barkat MQ, Cai J, Zhu H, Zeng LH, Wu X. Control of mitochondria-associated endoplasmic reticulum membranes by protein S-palmitoylation: Novel therapeutic targets for neurodegenerative diseases. Ageing Res Rev 2023; 87:101920. [PMID: 37004843 DOI: 10.1016/j.arr.2023.101920] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023]
Abstract
Mitochondria-associated endoplasmic reticulum membranes (MAMs) are dynamic coupling structures between mitochondria and the endoplasmic reticulum (ER). As a new subcellular structure, MAMs combine the two critical organelle functions. Mitochondria and the ER could regulate each other via MAMs. MAMs are involved in calcium (Ca2+) homeostasis, autophagy, ER stress, lipid metabolism, etc. Researchers have found that MAMs are closely related to metabolic syndrome and neurodegenerative diseases (NDs). The formation of MAMs and their functions depend on specific proteins. Numerous protein enrichments, such as the IP3R-Grp75-VDAC complex, constitute MAMs. The changes in these proteins govern the interaction between mitochondria and the ER; they also affect the biological functions of MAMs. S-palmitoylation is a reversible protein post-translational modification (PTM) that mainly occurs on protein cysteine residues. More and more studies have shown that the S-palmitoylation of proteins is closely related to their membrane localization. Here, we first briefly describe the composition and function of MAMs, reviewing the component and biological roles of MAMs mediated by S-palmitoylation, elaborating on S-palmitoylated proteins in Ca2+ flux, lipid rafts, and so on. We try to provide new insight into the molecular basis of MAMs-related diseases, mainly NDs. Finally, we propose potential drug compounds targeting S-palmitoylation.
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Affiliation(s)
- Qiangqiang He
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China; Department of Pharmacology, Hangzhou City University, Hangzhou 310015, China
| | - Meiyu Qu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Tingyu Shen
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jiakun Su
- Technology Center, China Tobacco Jiangxi Industrial Co. Ltd., Nanchang 330096, China
| | - Yana Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Chengyun Xu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Muhammad Qasim Barkat
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jibao Cai
- Technology Center, China Tobacco Jiangxi Industrial Co. Ltd., Nanchang 330096, China
| | - Haibin Zhu
- Department of Gynecology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Ling-Hui Zeng
- Department of Pharmacology, Hangzhou City University, Hangzhou 310015, China.
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University School of Medicine, Hangzhou 310058, China.
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10
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Jeyarajan S, Zhang IX, Arvan P, Lentz SI, Satin LS. Simultaneous Measurement of Changes in Mitochondrial and Endoplasmic Reticulum Free Calcium in Pancreatic Beta Cells. BIOSENSORS 2023; 13:382. [PMID: 36979594 PMCID: PMC10046164 DOI: 10.3390/bios13030382] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/28/2023] [Accepted: 03/08/2023] [Indexed: 05/28/2023]
Abstract
The free calcium (Ca2+) levels in pancreatic beta cell organelles have been the subject of many recent investigations. Under pathophysiological conditions, disturbances in these pools have been linked to altered intracellular communication and cellular dysfunction. To facilitate studies of subcellular Ca2+ signaling in beta cells and, particularly, signaling between the endoplasmic reticulum (ER) and mitochondria, we designed a novel dual Ca2+ sensor which we termed DS-1. DS-1 encodes two stoichiometrically fluorescent proteins within a single plasmid, G-CEPIA-er, targeted to the ER and R-CEPIA3-mt, targeted to mitochondria. Our goal was to simultaneously measure the ER and mitochondrial Ca2+ in cells in real time. The Kds of G-CEPIA-er and R-CEPIA3-mt for Ca2+ are 672 and 3.7 μM, respectively. Confocal imaging of insulin-secreting INS-1 832/13 expressing DS-1 confirmed that the green and red fluorophores correctly colocalized with organelle-specific fluorescent markers as predicted. Further, we tested whether DS-1 exhibited the functional properties expected by challenging an INS-1 cell to glucose concentrations or drugs having well-documented effects on the ER and mitochondrial Ca2+ handling. The data obtained were consistent with those seen using other single organelle targeted probes. These results taken together suggest that DS-1 is a promising new approach for investigating Ca2+ signaling within multiple organelles of the cell.
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Affiliation(s)
- Sivakumar Jeyarajan
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48105, USA; (S.J.)
| | - Irina X Zhang
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48105, USA; (S.J.)
| | - Peter Arvan
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105, USA
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48105, USA
| | - Stephen I. Lentz
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105, USA
| | - Leslie S. Satin
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48105, USA; (S.J.)
- Department of Internal Medicine, Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI 48105, USA
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11
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Sharifi S, Böger M, Lortz S, Mehmeti I. Luminal H 2 O 2 promotes ER Ca 2+ dysregulation and toxicity of palmitate in insulin-secreting INS-1E cells. FASEB J 2023; 37:e22685. [PMID: 36468845 DOI: 10.1096/fj.202201237r] [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: 08/03/2022] [Revised: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022]
Abstract
The endoplasmic reticulum (ER) lumen is not only the major site for the assembly and folding of newly synthesized proteins but also the main intracellular Ca2+ store. Ca2+ ions are involved in versatile biochemical processes, including posttranslational processing and folding of nascent proteins. Disruption of ER Ca2+ homeostasis is usually accompanied by an ER stress response that can ultimately lead to apoptosis if unresolved. Abnormal ER Ca2+ depletion has been linked to pancreatic β-cell dysfunction and death under lipotoxic conditions. However, the underlying mechanisms how the β-cell toxic saturated free fatty acid palmitate perturbs ER Ca2+ homeostasis and its interplay with other organelles are not fully understood. In the present study, we demonstrate that treatment of insulin-secreting INS-1E cells with palmitate diminished ER Ca2+ levels, elevated cytosolic/mitochondrial Ca2+ content, lowered the mitochondrial membrane potential, and ATP content. In addition, palmitate-pretreated β-cells contained significantly less luminal Ca2+ , revealed a severely impaired ER Ca2+ reuptake rate, and substantially lower insulin content. Importantly, detoxification of luminal H2 O2 by expression of the ER-resident glutathione peroxidase 8 (GPx8) abrogated the lipotoxic effects of palmitate. Moreover, GPx8 supported oxidative protein folding and preserved insulin content under lipotoxic conditions. A direct involvement of luminal H2 O2 in palmitate-mediated ER Ca2+ depletion could be corroborated by the ectopic expression of an ER-luminal active catalase. Our data point to the critical role of luminal H2 O2 in palmitate-mediated depletion of ER Ca2+ through redox-dependent impairment of Ca2+ ATPase pump activity upstream of mitochondrial dysfunction in insulin-secreting INS-1E cells.
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Affiliation(s)
- Sarah Sharifi
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Maren Böger
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Stephan Lortz
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
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12
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Beaulant A, Dia M, Pillot B, Chauvin MA, Ji-Cao J, Durand C, Bendridi N, Chanon S, Vieille-Marchiset A, Da Silva CC, Patouraux S, Anty R, Iannelli A, Tran A, Gual P, Vidal H, Gomez L, Paillard M, Rieusset J. Endoplasmic reticulum-mitochondria miscommunication is an early and causal trigger of hepatic insulin resistance and steatosis. J Hepatol 2022; 77:710-722. [PMID: 35358616 DOI: 10.1016/j.jhep.2022.03.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 02/18/2022] [Accepted: 03/07/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS Hepatic insulin resistance in obesity and type 2 diabetes was recently associated with endoplasmic reticulum (ER)-mitochondria miscommunication. These contact sites (mitochondria-associated membranes: MAMs) are highly dynamic and involved in many functions; however, whether MAM dysfunction plays a causal role in hepatic insulin resistance and steatosis is not clear. Thus, we aimed to determine whether and how organelle miscommunication plays a role in the onset and progression of hepatic metabolic impairment. METHODS We analyzed hepatic ER-mitochondria interactions and calcium exchange in a time-dependent and reversible manner in mice with diet-induced obesity. Additionally, we used recombinant adenovirus to express a specific organelle spacer or linker in mouse livers, to determine the causal impact of MAM dysfunction on hepatic metabolic alterations. RESULTS Disruption of ER-mitochondria interactions and calcium exchange is an early event preceding hepatic insulin resistance and steatosis in mice with diet-induced obesity. Interestingly, an 8-week reversal diet concomitantly reversed hepatic organelle miscommunication and insulin resistance in obese mice. Mechanistically, disrupting structural and functional ER-mitochondria interactions through the hepatic overexpression of the organelle spacer FATE1 was sufficient to impair hepatic insulin action and glucose homeostasis. In addition, FATE1-mediated organelle miscommunication disrupted lipid-related mitochondrial oxidative metabolism and induced hepatic steatosis. Conversely, reinforcement of ER-mitochondria interactions through hepatic expression of a synthetic linker prevented diet-induced glucose intolerance after 4 weeks' overnutrition. Importantly, ER-mitochondria miscommunication was confirmed in the liver of obese patients with type 2 diabetes, and correlated with glycemia, HbA1c and HOMA-IR index. CONCLUSIONS ER-mitochondria miscommunication is an early causal trigger of hepatic insulin resistance and steatosis, and can be reversed by switching to a healthy diet. Thus, targeting MAMs could help to restore metabolic homeostasis. LAY SUMMARY The literature suggests that interactions between the endoplasmic reticulum and mitochondria could play a role in hepatic insulin resistance and steatosis during chronic obesity. In the present study, we reappraised the time-dependent regulation of hepatic endoplasmic reticulum-mitochondria interactions and calcium exchange, investigating reversibility and causality, in mice with diet-induced obesity. We also assessed the relevance of our findings to humans. We show that organelle miscommunication is an early causal trigger of hepatic insulin resistance and steatosis that can be improved by nutritional strategies.
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Affiliation(s)
- Agathe Beaulant
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Maya Dia
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Bruno Pillot
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Marie-Agnes Chauvin
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Jingwei Ji-Cao
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Christine Durand
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Nadia Bendridi
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Stephanie Chanon
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Aurelie Vieille-Marchiset
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Claire Crola Da Silva
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Stéphanie Patouraux
- Université Côte d'Azur, CHU, INSERM, U1065, C3M, Nice, France; Université Côte d'Azur, INSERM, U1065, C3M, Nice, France
| | - Rodolphe Anty
- Université Côte d'Azur, CHU, INSERM, U1065, C3M, Nice, France; Université Côte d'Azur, INSERM, U1065, C3M, Nice, France
| | - Antonio Iannelli
- Université Côte d'Azur, CHU, INSERM, U1065, C3M, Nice, France; Université Côte d'Azur, INSERM, U1065, C3M, Nice, France
| | - Albert Tran
- Université Côte d'Azur, CHU, INSERM, U1065, C3M, Nice, France; Université Côte d'Azur, INSERM, U1065, C3M, Nice, France
| | - Philippe Gual
- Université Côte d'Azur, INSERM, U1065, C3M, Nice, France
| | - Hubert Vidal
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Ludovic Gomez
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Melanie Paillard
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France
| | - Jennifer Rieusset
- Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, F-69310 Pierre-Bénite and F-69500 Bron, France.
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13
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Integrative modeling of the cell. Acta Biochim Biophys Sin (Shanghai) 2022; 54:1213-1221. [PMID: 36017893 PMCID: PMC9909318 DOI: 10.3724/abbs.2022115] [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] [Indexed: 12/29/2022] Open
Abstract
A whole-cell model represents certain aspects of the cell structure and/or function. Due to the high complexity of the cell, an integrative modeling approach is often taken to utilize all available information including experimental data, prior knowledge and prior models. In this review, we summarize an emerging workflow of whole-cell modeling into five steps: (i) gather information; (ii) represent the modeled system into modules; (iii) translate input information into scoring function; (iv) sample the whole-cell model; (v) validate and interpret the model. In particular, we propose the integrative modeling of the cell by combining available (whole-cell) models to maximize the accuracy, precision, and completeness. In addition, we list quantitative predictions of various aspects of cell biology from existing whole-cell models. Moreover, we discuss the remaining challenges and future directions, and highlight the opportunity to establish an integrative spatiotemporal multi-scale whole-cell model based on a community approach.
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14
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Li J, Yan H, Xiang R, Yang W, Ye J, Yin R, Yang J, Chi Y. ATP Secretion and Metabolism in Regulating Pancreatic Beta Cell Functions and Hepatic Glycolipid Metabolism. Front Physiol 2022; 13:918042. [PMID: 35800345 PMCID: PMC9253475 DOI: 10.3389/fphys.2022.918042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Diabetes (DM), especially type 2 diabetes (T2DM) has become one of the major diseases severely threatening public health worldwide. Islet beta cell dysfunctions and peripheral insulin resistance including liver and muscle metabolic disorder play decisive roles in the pathogenesis of T2DM. Particularly, increased hepatic gluconeogenesis due to insulin deficiency or resistance is the central event in the development of fasting hyperglycemia. To maintain or restore the functions of islet beta cells and suppress hepatic gluconeogenesis is crucial for delaying or even stopping the progression of T2DM and diabetic complications. As the key energy outcome of mitochondrial oxidative phosphorylation, adenosine triphosphate (ATP) plays vital roles in the process of almost all the biological activities including metabolic regulation. Cellular adenosine triphosphate participates intracellular energy transfer in all forms of life. Recently, it had also been revealed that ATP can be released by islet beta cells and hepatocytes, and the released ATP and its degraded products including ADP, AMP and adenosine act as important signaling molecules to regulate islet beta cell functions and hepatic glycolipid metabolism via the activation of P2 receptors (ATP receptors). In this review, the latest findings regarding the roles and mechanisms of intracellular and extracellular ATP in regulating islet functions and hepatic glycolipid metabolism would be briefly summarized and discussed.
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Affiliation(s)
- Jing Li
- Department of Endocrinology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Han Yan
- Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Rui Xiang
- Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Weili Yang
- Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jingjing Ye
- Department of Central Laboratory and Institute of Clinical Molecular Biology, Peking University People’s Hospital, Beijing, China
- Key Laboratory of Trauma and Neural Regeneration (Peking University), National Center for Trauma Medicine, Trauma Medicine Center, Peking University People’s Hospital, Beijing, China
| | - Ruili Yin
- Beijing Key Laboratory of Diabetes Prevention and Research, Center for Endocrine Metabolic and Immune Disease, Beijing Luhe Hospital, Capital Medical University, Beijing, China
| | - Jichun Yang
- Key Laboratory of Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- *Correspondence: Jichun Yang, ; Yujing Chi,
| | - Yujing Chi
- Department of Central Laboratory and Institute of Clinical Molecular Biology, Peking University People’s Hospital, Beijing, China
- *Correspondence: Jichun Yang, ; Yujing Chi,
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15
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Ke M, Lin F, Wang H, He G, Feng J, Song L, Xu Y, Liu J. Sigma‑1 receptor overexpression promotes proliferation and ameliorates cell apoptosis in β‑cells. Mol Med Rep 2022; 25:170. [PMID: 35302175 PMCID: PMC8971912 DOI: 10.3892/mmr.2022.12686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 02/16/2022] [Indexed: 11/24/2022] Open
Abstract
Sigma‑1 receptor (Sig‑1R) is a class of orphan receptors, the potential role of which in pancreatic islet cells remains poorly understood. The present study aimed to investigate the role of Sig‑1R in islet β‑cell proliferation and examine the effects of Sig‑1R on islet β‑cell injury under lipotoxic conditions. Sig‑1R‑overexpressing MIN6 cells were generated by lentiviral vector transfection. The effect of Sig‑1R overexpression on cell proliferation detected by EdU staining, cell cycle progression by propidium iodide (PI), apoptosis by Annexin V‑APC/PI, mitochondrial membrane potential by Mitolite Red and cytoplasmic Ca2+ levelsby Fura‑2/AM in islet β‑cells were measured by flow cytometry. Western blot analysis was used to measure protein expression levels of endoplasmic reticulum (ER) stress markers glucose‑regulated protein 78 and C/EBP homologous protein, mitochondrial apoptotic proteins Bcl‑2‑associated X and Bcl‑2 and cytochrome c. In addition, ATP levels and insulin secretion were separately measured using ATP Assay and mouse insulin ELISA. Mitochondria‑associated ER membrane (MAM) structures in MIN6 cells were then detected using transmission electron microscopy. Protein disulfide isomerase expression and possible colocalization between inositol 1,4,5‑trisphosphate receptor and voltage‑dependent anion channel 1 were examined using immunofluorescence. Sig‑1R overexpression was found to promote β‑cell proliferation by accelerating cell cycle progression. Furthermore, Sig‑1R overexpression ameliorated the apoptosis rate whilst impairing insulin secretion induced by palmitic acid by relieving ER stress and mitochondrial dysfunction in MIN6 cells. Sig‑1R overexpression also promoted Ca2+ transport between mitochondria and ER by increasing the quantity of ER adjacent to mitochondria in the 50‑nm range. It was concluded that Sig‑1R overexpression conferred protective effects on β‑cells against lipotoxicity as a result of the promotion of cell proliferation and inhibition of ER stress and oxidative stress, by regulating the structure of MAM.
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Affiliation(s)
- Mengting Ke
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Fengping Lin
- Department of Endocrinology, Xianning Central Hospital, Xianning, Hubei 437100, P.R. China
| | - Huawei Wang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Guangzhen He
- Department of Pediatrics, Affiliated Taihe Hospital of Hubei University of Medicine, Shiyan, Hubei 442002, P.R. China
| | - Jieyuan Feng
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Linyang Song
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
| | - Jie Liu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China
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16
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Sidarala V, Zhu J, Levi-D'Ancona E, Pearson GL, Reck EC, Walker EM, Kaufman BA, Soleimanpour SA. Mitofusin 1 and 2 regulation of mitochondrial DNA content is a critical determinant of glucose homeostasis. Nat Commun 2022; 13:2340. [PMID: 35487893 PMCID: PMC9055072 DOI: 10.1038/s41467-022-29945-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/21/2022] [Indexed: 02/01/2023] Open
Abstract
The dynamin-like GTPases Mitofusin 1 and 2 (Mfn1 and Mfn2) are essential for mitochondrial function, which has been principally attributed to their regulation of fission/fusion dynamics. Here, we report that Mfn1 and 2 are critical for glucose-stimulated insulin secretion (GSIS) primarily through control of mitochondrial DNA (mtDNA) content. Whereas Mfn1 and Mfn2 individually were dispensable for glucose homeostasis, combined Mfn1/2 deletion in β-cells reduced mtDNA content, impaired mitochondrial morphology and networking, and decreased respiratory function, ultimately resulting in severe glucose intolerance. Importantly, gene dosage studies unexpectedly revealed that Mfn1/2 control of glucose homeostasis was dependent on maintenance of mtDNA content, rather than mitochondrial structure. Mfn1/2 maintain mtDNA content by regulating the expression of the crucial mitochondrial transcription factor Tfam, as Tfam overexpression ameliorated the reduction in mtDNA content and GSIS in Mfn1/2-deficient β-cells. Thus, the primary physiologic role of Mfn1 and 2 in β-cells is coupled to the preservation of mtDNA content rather than mitochondrial architecture, and Mfn1 and 2 may be promising targets to overcome mitochondrial dysfunction and restore glucose control in diabetes.
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Affiliation(s)
- Vaibhav Sidarala
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Jie Zhu
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Elena Levi-D'Ancona
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Gemma L Pearson
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emma C Reck
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emily M Walker
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Brett A Kaufman
- Vascular Medicine Institute, Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States
| | - Scott A Soleimanpour
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48105, United States.
- VA Ann Arbor Healthcare System, Ann Arbor, MI, 48105, United States.
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Tiwary S, Nandwani A, Khan R, Datta M. GRP75 mediates endoplasmic reticulum-mitochondria coupling during palmitate-induced pancreatic β-cell apoptosis. J Biol Chem 2021; 297:101368. [PMID: 34756890 PMCID: PMC8637649 DOI: 10.1016/j.jbc.2021.101368] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 10/18/2021] [Accepted: 10/27/2021] [Indexed: 10/27/2022] Open
Abstract
The endoplasmic reticulum (ER) and mitochondria are structurally connected with each other at specific sites termed mitochondria-associated membranes (MAMs). These physical links are composed of several tethering proteins and are important during varied cellular processes, such as calcium homeostasis, lipid metabolism and transport, membrane biogenesis, and organelle remodeling. However, the attributes of specific tethering proteins in these cellular functions remain debatable. Here, we present data to show that one such tether protein, glucose regulated protein 75 (GRP75), is essential in increasing ER-mitochondria contact during palmitate-induced apoptosis in pancreatic insulinoma cells. We demonstrate that palmitate increased GRP75 levels in mouse and rat pancreatic insulinoma cells as well as in mouse primary islet cells. This was associated with increased mitochondrial Ca2+ transfer, impaired mitochondrial membrane potential, increased ROS production, and enhanced physical coupling between the ER and mitochondria. Interestingly, GRP75 inhibition prevented these palmitate-induced cellular aberrations. Additionally, GRP75 overexpression alone was sufficient to impair mitochondrial membrane potential, increase mitochondrial Ca2+ levels and ROS generation, augment ER-mitochondria contact, and induce apoptosis in these cells. In vivo injection of palmitate induced hyperglycemia and hypertriglyceridemia, as well as impaired glucose and insulin tolerance in mice. These animals also exhibited elevated GRP75 levels accompanied by enhanced apoptosis within the pancreatic islets. Our findings suggest that GRP75 is critical in mediating palmitate-induced ER-mitochondrial interaction leading to apoptosis in pancreatic islet cells.
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Affiliation(s)
- Shweta Tiwary
- Integrative and Functional Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Arun Nandwani
- Integrative and Functional Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Rukshar Khan
- Integrative and Functional Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, India; Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Malabika Datta
- Integrative and Functional Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India.
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18
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PACS-2 attenuates diabetic kidney disease via the enhancement of mitochondria-associated endoplasmic reticulum membrane formation. Cell Death Dis 2021; 12:1107. [PMID: 34836936 PMCID: PMC8626491 DOI: 10.1038/s41419-021-04408-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 02/07/2023]
Abstract
The altered homeostasis of mitochondria-associated endoplasmic reticulum (ER) membranes (MAM) was closely associated with the pathological process of nervous system diseases and insulin resistance. Here, the exact implication of phosphofurin acidic cluster sorting protein 2 (PCAS-2), an anchor protein in the MAM interface, in diabetic kidney disease was investigated. In the kidneys of type 1 and type 2 diabetes mice and HG-induced HK-2 cells, a notable disruption of ER-mitochondria interactions, accompanied by a decreased PACS-2 expression in all subcellular fractions. Furthermore, PACS-2 knockout mice with diabetes displayed accelerated development of proteinuria, deterioration of kidney function, and aggravated disruption of MAM area, ER stress, mitochondrial dysfunction, renal apoptosis, and fibrosis. However, overexpression of PACS-2 effectively protected diabetic kidneys and HG-treated HK-2 cells from renal tubular impairments. Importantly, experimental uncoupling of ER-mitochondria contacts reversed the protective effects of PACS-2 restoration on HK-2 cells under HG conditions. In summary, our data indicate a pivotal role of PACS-2 in the development of diabetic renal tubular injury via the stabilization of MAM.
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19
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Lu L, Zhuang L, Shen X, Yang L. Glucotoxicity Activation of IL6 and IL11 and Subsequent Induction of Fibrosis May Be Involved in the Pathogenesis of Islet Dysfunction. Front Mol Biosci 2021; 8:708127. [PMID: 34497830 PMCID: PMC8419433 DOI: 10.3389/fmolb.2021.708127] [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: 05/11/2021] [Accepted: 08/02/2021] [Indexed: 12/26/2022] Open
Abstract
Background: Islet dysfunction is the main pathological process of type 2 diabetes mellitus (T2DM). Fibrosis causes islet dysfunction, but the current mechanism is still unclear. Here, bioinformatics analysis identified gene clusters closely related to T2DM and differentially expressed genes related to fibrosis, and animal models verified the roles of these genes. Methods: Human islet transcriptomic datasets were obtained from the Gene Expression Omnibus (GEO), and weighted gene coexpression network analysis (WGCNA) was applied to screen the key gene modules related to T2DM and analyze the correlations between the modules and clinical characteristics. Enrichment analysis was performed to identify the functions and pathways of the key module genes. WGCNA, protein-protein interaction (PPI) analysis and receiver operating characteristic (ROC) curve analysis were used to screen the hub genes. The hub genes were verified in another GEO dataset, the islets of high-fat diet (HFD)-fed Sprague-Dawley rats were observed by H&E and Masson’s trichrome staining, the fibrotic proteins were verified by immunofluorescence, and the hub genes were tested by immunohistochemistry. Results: The top 5,000 genes were selected according to the median absolute deviation, and 18 modules were analyzed. The yellow module was highly associated with T2DM, and its positive correlation with glycated hemoglobin (HbA1c) was significantly stronger than that with body mass index (BMI). Enrichment analysis revealed that extracellular matrix organization, the collagen-containing extracellular matrix and cytokine−cytokine receptor interaction might influence T2DM progression. The top three hub genes, interleukin 6 (IL6), IL11 and prostaglandin-endoperoxide synthase 2 (PTGS2), showed upregulated expression in T2DM. In the validation dataset, IL6, IL11, and PTGS2 levels were upregulated in T2DM, and IL6 and PTGS2 expression was positively correlated with HbA1c and BMI; however, IL11 was positively correlated only with HbA1c. In HFD-fed Sprague-Dawley rats, the positive of IL6 and IL11 in islets was stronger, but PTGS2 expression was not significantly altered. The extent of fibrosis, irregular cellular arrangement and positive actin alpha 2 (ACTA2) staining in islets was significantly greater in HFD-fed rats than in normal diet-fed rats. Conclusion: Glucotoxicity is a major factor leading to increased IL6 and IL11 expression, and IL6-and IL11-induced fibrosis might be involved in islet dysfunction.
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Affiliation(s)
- Liqin Lu
- Endocrinology Department, The First Affifiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Lili Zhuang
- Endocrinology Department, The First Affifiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Ximei Shen
- Endocrinology Department, The First Affifiliated Hospital of Fujian Medical University, Fuzhou, China.,Diabetes Research Institute of Fujian Province, Fuzhou, China
| | - Liyong Yang
- Endocrinology Department, The First Affifiliated Hospital of Fujian Medical University, Fuzhou, China.,Diabetes Research Institute of Fujian Province, Fuzhou, China
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20
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Communications between Mitochondria and Endoplasmic Reticulum in the Regulation of Metabolic Homeostasis. Cells 2021; 10:cells10092195. [PMID: 34571844 PMCID: PMC8468463 DOI: 10.3390/cells10092195] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 12/18/2022] Open
Abstract
Mitochondria associated membranes (MAM), which are the contact sites between endoplasmic reticulum (ER) and mitochondria, have emerged as an important hub for signaling molecules to integrate the cellular and organelle homeostasis, thus facilitating the adaptation of energy metabolism to nutrient status. This review explores the dynamic structural and functional features of the MAM and summarizes the various abnormalities leading to the impaired insulin sensitivity and metabolic diseases.
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21
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Ding XW, Robinson M, Li R, Aldhowayan H, Geetha T, Babu JR. Mitochondrial dysfunction and beneficial effects of mitochondria-targeted small peptide SS-31 in Diabetes Mellitus and Alzheimer's disease. Pharmacol Res 2021; 171:105783. [PMID: 34302976 DOI: 10.1016/j.phrs.2021.105783] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/07/2021] [Accepted: 07/20/2021] [Indexed: 12/11/2022]
Abstract
Diabetes and Alzheimer's disease are common chronic illnesses in the United States and lack clearly demonstrated therapeutics. Mitochondria, the "powerhouse of the cell", is involved in the homeostatic regulation of glucose, energy, and reduction/oxidation reactions. The mitochondria has been associated with the etiology of metabolic and neurological disorders through a dysfunction of regulation of reactive oxygen species. Mitochondria-targeted chemicals, such as the Szeto-Schiller-31 peptide, have advanced therapeutic potential through the inhibition of oxidative stress and the restoration of normal mitochondrial function as compared to traditional antioxidants, such as vitamin E. In this article, we summarize the pathophysiological relevance of the mitochondria and the beneficial effects of Szeto-Schiller-31 peptide in the treatment of Diabetes and Alzheimer's disease.
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Affiliation(s)
- Xiao-Wen Ding
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA
| | - Megan Robinson
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA
| | - Rongzi Li
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA
| | - Hadeel Aldhowayan
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA
| | - Thangiah Geetha
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA; Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL 36849, USA
| | - Jeganathan Ramesh Babu
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL 36849, USA; Boshell Metabolic Diseases and Diabetes Program, Auburn University, Auburn, AL 36849, USA.
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22
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Madec AM, Perrier J, Panthu B, Dingreville F. Role of mitochondria-associated endoplasmic reticulum membrane (MAMs) interactions and calcium exchange in the development of type 2 diabetes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 363:169-202. [PMID: 34392929 DOI: 10.1016/bs.ircmb.2021.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glucotoxicity-induced β-cell dysfunction in type 2 diabetes is associated with alterations of mitochondria and the endoplasmic reticulum (ER). Mitochondria and ER form a network in cells that controls cell function and fate. Mitochondria of the pancreatic β cell play a central role in the secretion of insulin in response to glucose through their ability to produce ATP. Both organelles interact at contact sites, defined as mitochondria-associated membranes (MAMs), which were recently implicated in the regulation of glucose homeostasis. Here, we review MAM functions in the cell and we focus on the crosstalk between the ER and Mitochondria in the context of T2D, highlighting the pivotal role played by MAMs especially in β cells through inter-organelle calcium exchange and glucotoxicity-associated β cell dysfunction.
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Affiliation(s)
| | - Johan Perrier
- CarMeN Laboratory, INSERM U1060, INRA U1397, Lyon, France
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23
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Ke M, He G, Wang H, Cheng S, Xu Y. Sigma receptor knockdown augments dysfunction and apoptosis of beta cells induced by palmitate. Exp Biol Med (Maywood) 2021; 246:1491-1499. [PMID: 33715527 PMCID: PMC8283253 DOI: 10.1177/1535370221997780] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 01/19/2021] [Indexed: 11/17/2022] Open
Abstract
Sigma-1 receptor (Sig-1R) is located in the endoplasmic reticulum (ER) and clustered on the mitochondria related endoplasmic membranes, which are involved in the regulation of nervous system disease. Here, we designed Sig-1R silence MIN6 cells and studied the influence of Sig-1R silence on beta cells. We showed Sig-1R inactivation in MIN6 cells could not only decrease cell proliferation but also inhibit cell cycle, and this inhibitory effect on cell cycle might be achieved by regulating the FoxM1/Plk1/Cenpa pathway. Moreover, Sig-1R deficiency increased MIN6 cells sensitivity to lipotoxicity, exaggerated palmitate (PA)-induced apoptosis, and impaired insulin secretion. On the other hand, ER chaperone GRP78 and ER proapoptotic molecules CHOP increased in Sig-1R knockdown MIN6 cells. The ATP level decreased and reactive oxygen species (ROS) increased in this kind of cells. Furthermore not only GRP78 and CHOP levels, but also ATP and ROS levels changed more in Sig-1R silence cells after cultured with PA. Therefore, Sig-1R deficiency exaggerated PA induced beta cells apoptosis by aggravating ER stress and mitochondrial dysfunction. Together, our study showed that Sig-1R might influence the proliferation, apoptosis, and function of beta cells.
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Affiliation(s)
- Mengting Ke
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, China
| | - Guangzhen He
- Department of Pediatrics, Affiliated Taihe Hospital of Hubei University of Medicine, Shiyan, Hubei 442002, China
| | - Huawei Wang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, China
| | - Siyuan Cheng
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, China
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24
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Zhao Y, Jia WW, Ren S, Xiao W, Li GW, Jin L, Lin Y. Difluoromethylornithine attenuates isoproterenol-induced cardiac hypertrophy by regulating apoptosis, autophagy and the mitochondria-associated membranes pathway. Exp Ther Med 2021; 22:870. [PMID: 34194548 PMCID: PMC8237397 DOI: 10.3892/etm.2021.10302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 04/28/2021] [Indexed: 12/20/2022] Open
Abstract
Myocardial hypertrophy is an independent risk factor of cardiovascular diseases and is closely associated with the incidence of heart failure. In the present study, we hypothesized that difluoromethylornithine (DFMO) could attenuate cardiac hypertrophy through mitochondria-associated membranes (MAM) and autophagy. Cardiac hypertrophy was induced in male rats by intravenous administration of isoproterenol (ISO; 5 mg/kg/day) for 1, 3,7 and 14 days. For DFMO treatment group, rats were given ISO (5 mg/kg/day) for 14 days and 2% DFMO in their water for 4 weeks. The expression of atrial natriuretic peptide (ANP) mRNA,heart parameters, apoptosis rate, fibrotic area and protein expressions of cleaved caspase3/9, GRP75, Mfn2, CypD and VDAC1 were measured to confirm the development of cardiac hypertrophy, apoptosis and autophagy induced by ISO. ANP mRNA and MAM protein expression levels were assessed by reverse transcription-quantitative PCR and western blotting to evaluate hypertrophy and the effects of DFMO oral administration. The results demonstrated that heart parameters, ANP mRNA levels, fibrotic area and apoptosis rate were significantly increased in the heart tissue for ISO 7 and 14 day groups compared with the control group. Furthermore, treatment with DFMO significantly inhibited these indicators, and DFMO downregulated the MAM signaling pathway and upregulated the autophagy pathway in heart tissue compared with the ISO 14 day group. Overall, all ISO-induced changes analyzed in the present study were attenuated following treatment with DFMO. The findings form this study suggested that DFMO treatment may be considered as a potential strategy for preventing ISO-induced cardiac hypertrophy.
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Affiliation(s)
- Yu Zhao
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Wei-Wei Jia
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - San Ren
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Wei Xiao
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Guang-Wei Li
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Li Jin
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
| | - Yan Lin
- Department of Pathophysiology, Qiqihar Medical University, Qiqihar, Heilongjiang 161006, P.R. China
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25
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Pearson GL, Gingerich MA, Walker EM, Biden TJ, Soleimanpour SA. A Selective Look at Autophagy in Pancreatic β-Cells. Diabetes 2021; 70:1229-1241. [PMID: 34016598 PMCID: PMC8275885 DOI: 10.2337/dbi20-0014] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/22/2021] [Indexed: 12/15/2022]
Abstract
Insulin-producing pancreatic β-cells are central to glucose homeostasis, and their failure is a principal driver of diabetes development. To preserve optimal health β-cells must withstand both intrinsic and extrinsic stressors, ranging from inflammation to increased peripheral insulin demand, in addition to maintaining insulin biosynthesis and secretory machinery. Autophagy is increasingly being appreciated as a critical β-cell quality control system vital for glycemic control. Here we focus on the underappreciated, yet crucial, roles for selective and organelle-specific forms of autophagy as mediators of β-cell health. We examine the unique molecular players underlying each distinct form of autophagy in β-cells, including selective autophagy of mitochondria, insulin granules, lipid, intracellular amyloid aggregates, endoplasmic reticulum, and peroxisomes. We also describe how defects in selective autophagy pathways contribute to the development of diabetes. As all forms of autophagy are not the same, a refined view of β-cell selective autophagy may inform new approaches to defend against the various insults leading to β-cell failure in diabetes.
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Affiliation(s)
- Gemma L Pearson
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | | | - Emily M Walker
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | | | - Scott A Soleimanpour
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Veterans Affairs Ann Arbor Health Care System, Ann Arbor, MI
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26
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Mitochondrial remodelling-a vicious cycle in diabetic complications. Mol Biol Rep 2021; 48:4721-4731. [PMID: 34023988 DOI: 10.1007/s11033-021-06408-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
Abstract
Diabetes mellitus (DM) is a chronic, metabolic condition characterized by excessive blood glucose that causes perturbations in physiological functioning of almost all the organs of human body. This devastating metabolic disease has its implications in cognitive decline, heart damage, renal, retinal and neuronal complications that severely affects quality of life and associated with decreased life expectancy. Mitochondria possess adaptive mechanisms to meet the cellular energy demand and combat cellular stress. In recent years mitochondrial homeostasis has been point of focus where several mechanisms regulating mitochondrial health and function are evaluated. Mitochondrial dynamics plays crucial role in maintaining healthy mitochondria in cell under physiological as well as stress condition. Mitochondrial dynamics and corresponding regulating mechanisms have been implicated in progression of metabolic disorders including diabetes and its complications. In current review we have discussed about role of mitochondrial dynamics under physiological and pathological conditions. Also, modulation of mitochondrial fission and fusion in diabetic complications are described. The available literature supports mitochondrial remodelling as reliable target for diabetic complications.
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27
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Venditti R, Wilson C, De Matteis MA. Regulation and physiology of membrane contact sites. Curr Opin Cell Biol 2021; 71:148-157. [PMID: 33932623 DOI: 10.1016/j.ceb.2021.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/18/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Membrane contact sites (MCSs) in addition to impacting the functions of membrane-limited organelles also have a role in the spatial and functional organization of cells, tissues and whole organisms. MCSs have been identified between all organelles and the identification of their molecular composition has progressed significantly in recent years. Equally important is how MCSs respond dynamically to physiological stimuli, how this is regulated, and the physiological roles of MCSs in tissues and at the organismal level, an area that still remains relatively unexplored. In the present review, we focus on the regulation of MCSs, considerations of their function at the organismal level, and how mutations of MCS components linked to genetic diseases might inform us about their physiological relevance.
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Affiliation(s)
- Rossella Venditti
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy
| | - Cathal Wilson
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy.
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28
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Ketogenic Diet Suppressed T-Regulatory Cells and Promoted Cardiac Fibrosis via Reducing Mitochondria-Associated Membranes and Inhibiting Mitochondrial Function. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5512322. [PMID: 33959215 PMCID: PMC8075689 DOI: 10.1155/2021/5512322] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/28/2021] [Accepted: 03/22/2021] [Indexed: 02/05/2023]
Abstract
Ketogenic diet (KD) is popular in diabetic patients but its cardiac safety and efficiency on the heart are unknown. The aim of the present study is to determine the effects and the underlined mechanisms of KD on cardiac function in diabetic cardiomyopathy (DCM). We used db/db mice to model DCM, and different diets (regular or KD) were used. Cardiac function and interstitial fibrosis were determined. T-regulatory cell (Treg) number and functions were evaluated. The effects of ketone body (KB) on fatty acid (FA) and glucose metabolism, mitochondria-associated endoplasmic reticulum membranes (MAMs), and mitochondrial respiration were assessed. The mechanisms via which KB regulated MAMs and Tregs were addressed. KD improved metabolic indices in db/db mice. However, KD impaired cardiac diastolic function and exacerbated ventricular fibrosis. Proportions of circulatory CD4+CD25+Foxp3+ cells in whole blood cells and serum levels of IL-4 and IL-10 were reduced in mice fed with KD. KB suppressed the differentiation to Tregs from naive CD4+ T cells. Cultured medium from KB-treated Tregs synergically activated cardiac fibroblasts. Meanwhile, KB inhibited Treg proliferation and productions of IL-4 and IL-10. Treg MAMs, mitochondrial respiration and respiratory complexes, and FA synthesis and oxidation were all suppressed by KB while glycolytic levels were increased. L-carnitine reversed Treg proliferation and function inhibited by KB. Proportions of ST2L+ cells in Tregs were reduced by KB, as well as the production of ST2L ligand, IL-33. Reinforcement expressions of ST2L in Tregs counteracted the reductions in MAMs, mitochondrial respiration, and Treg proliferations and productions of Treg cytokines IL-4 and IL-10. Therefore, despite the improvement of metabolic indices, KD impaired Treg expansion and function and promoted cardiac fibroblast activation and interstitial fibrosis. This could be mainly mediated by the suppression of MAMs and fatty acid metabolism inhibition via blunting IL-33/ST2L signaling.
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29
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Vig S, Lambooij JM, Zaldumbide A, Guigas B. Endoplasmic Reticulum-Mitochondria Crosstalk and Beta-Cell Destruction in Type 1 Diabetes. Front Immunol 2021; 12:669492. [PMID: 33936111 PMCID: PMC8085402 DOI: 10.3389/fimmu.2021.669492] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/29/2021] [Indexed: 12/11/2022] Open
Abstract
Beta-cell destruction in type 1 diabetes (T1D) results from the combined effect of inflammation and recurrent autoimmunity. In response to inflammatory signals, beta-cells engage adaptive mechanisms where the endoplasmic reticulum (ER) and mitochondria act in concert to restore cellular homeostasis. In the recent years it has become clear that this adaptive phase may trigger the development of autoimmunity by the generation of autoantigens recognized by autoreactive CD8 T cells. The participation of the ER stress and the unfolded protein response to the increased visibility of beta-cells to the immune system has been largely described. However, the role of the other cellular organelles, and in particular the mitochondria that are central mediator for beta-cell survival and function, remains poorly investigated. In this review we will dissect the crosstalk between the ER and mitochondria in the context of T1D, highlighting the key role played by this interaction in beta-cell dysfunctions and immune activation, especially through regulation of calcium homeostasis, oxidative stress and generation of mitochondrial-derived factors.
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Affiliation(s)
- Saurabh Vig
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Joost M. Lambooij
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
| | - Arnaud Zaldumbide
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Bruno Guigas
- Department of Parasitology, Leiden University Medical Center, Leiden, Netherlands
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30
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Balancing ER-Mitochondrial Ca 2+ Fluxes in Health and Disease. Trends Cell Biol 2021; 31:598-612. [PMID: 33678551 DOI: 10.1016/j.tcb.2021.02.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/29/2021] [Accepted: 02/02/2021] [Indexed: 02/08/2023]
Abstract
Organelles cooperate with each other to control cellular homeostasis and cell functions by forming close connections through membrane contact sites. Important contacts are present between the endoplasmic reticulum (ER), the main intracellular Ca2+-storage organelle, and the mitochondria, the organelle responsible not only for the majority of cellular ATP production but also for switching on cell death processes. Several Ca2+-transport systems focalize at these contact sites, thereby enabling the efficient transmission of Ca2+ signals from the ER toward mitochondria. This provides tight control of mitochondrial functions at the microdomain level. Here, we discuss how ER-mitochondrial Ca2+ transfers support cell function and how their dysregulation underlies, drives, or contributes to pathogenesis and pathophysiology, with a major focus on cancer and neurodegeneration but also with attention to other diseases such as diabetes and rare genetic diseases.
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31
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Reschke F, Rohayem J, Maffei P, Dassie F, Schwandt A, de Beaufort C, Toni S, Szypowska A, Cardona-Hernandez R, Datz N, Klee K, Danne T. Collaboration for rare diabetes: understanding new treatment options for Wolfram syndrome. Endocrine 2021; 71:626-633. [PMID: 33527330 DOI: 10.1007/s12020-021-02622-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/09/2021] [Indexed: 12/18/2022]
Abstract
BACKGROUND Wolfram Syndrome is a very rare genetic disease causing diabetes mellitus, blindness, deafness, diabetes insipidus, and progressive brainstem degeneration. Neurologic symptoms of affected patients include ataxia, sleep apnea, loss of bladder control, dysphagia, loss of taste, and accompanying psychiatric symptoms as a sign of progressive neurodegeneration. Its genetic cause is mainly biallelic mutations of the Wolframin endoplasmatic reticulum transmembrane glycoprotein gene Wfs1. These result in increased ER stress, which in turn induces apoptosis and leads to the depletion of the corresponding cells and a loss of their physiological functions. Though diabetes mellitus is mostly treated by insulin, there is still no proven cure for the disease in general. It leads to premature death in affected individuals-usually within the 4th decade of live. CURRENT RESEARCH AND TREATMENT TRIALS Clinical studies are currently being conducted at various locations worldwide to test a therapy for the disease using various approaches. POTENTAIL OF VIRTUAL NETOWRKING As rare diseases in general represent a major challenge for individual clinicians and researchers due to the rarity of diagnosis, the lack of evidence and of value of existing research, international cooperation, coordination and networking leading to an alignment of different stakeholders is necessary to support patients and increase knowledge about these diseases, like wolfram syndrome. CONCLUSION ENDO-ERN and EURRECA are two EU-funded networks that aim to promote knowledge sharing, education and research on rare endocrine diseases.
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Affiliation(s)
- Felix Reschke
- Diabetes Center, Children's Hospital AUF DER BULT, Hannover, Germany.
| | - Julia Rohayem
- Centre of Reproductive Medicine and Andrology, Department of Clinical and Surgical Andrology, University of Münster, Muenster, Germany
| | - Pietro Maffei
- Department of Medicine (DIMED), Padua University Hospital, Padua, Italy.
| | - Francesca Dassie
- Department of Medicine (DIMED), Padua University Hospital, Padua, Italy
| | - Anke Schwandt
- Institute of Epidemiology and Medical Biometry, ZIBMT, Ulm University, Ulm, Germany
- German Center for Diabetes Research (DZD), Munich-Neuherberg, Germany
| | - Carine de Beaufort
- Pediatric Clinic, DECCP/Center Hospitalier de Luxembourg, Luxembourg, Grand-Duché de Luxembourg
| | - Sonia Toni
- Ospedale Pediatrico Meyer Firenze, Florence, Italy
| | | | | | - Nicolin Datz
- Diabetes Center, Children's Hospital AUF DER BULT, Hannover, Germany
| | - Katharina Klee
- Diabetes Center, Children's Hospital AUF DER BULT, Hannover, Germany
| | - Thomas Danne
- Diabetes Center, Children's Hospital AUF DER BULT, Hannover, Germany
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32
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Mitochondria Associated Membranes (MAMs): Architecture and physiopathological role. Cell Calcium 2021; 94:102343. [PMID: 33418313 DOI: 10.1016/j.ceca.2020.102343] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/27/2020] [Accepted: 12/27/2020] [Indexed: 12/17/2022]
Abstract
In the last decades, the communication between the Endoplasmic reticulum (ER) and mitochondria has obtained great attention: mitochondria-associated membranes (MAMs), which represent the contact sites between the two organelles, have indeed emerged as central hub involved in different fundamental cell processes, such as calcium signalling, apoptosis, autophagy and lipid biosynthesis. Consistently, dysregulation of ER-mitochondria crosstalk has been associated with different pathological conditions, ranging from diabetes to cancer and neurodegenerative diseases. In this review, we will try to summarize the current knowledge on MAMs' structure and functions in health and their relevance for human diseases.
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33
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Wang K, Cui Y, Lin P, Yao Z, Sun Y. JunD Regulates Pancreatic β-Cells Function by Altering Lipid Accumulation. Front Endocrinol (Lausanne) 2021; 12:689845. [PMID: 34335468 PMCID: PMC8322846 DOI: 10.3389/fendo.2021.689845] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/04/2021] [Indexed: 12/28/2022] Open
Abstract
The impairment of pancreatic β-cells function is partly caused by lipotoxicity, which aggravates the development of type 2 diabetes mellitus. Activator Protein 1 member JunD modulates apoptosis and oxidative stress. Recently, it has been found that JunD regulates lipid metabolism in hepatocytes and cardiomyocytes. Here, we studied the role of JunD in pancreatic β-cells. The lipotoxic effects of palmitic acid on INS-1 cells were measured, and JunD small-interfering RNA was used to assess the effect of JunD in regulating lipid metabolism and insulin secretion. The results showed that palmitic acid stimulation induced the overexpression of JunD, impaired glucose-stimulated insulin secretion, and increased intracellular lipid accumulation of β-cells. Moreover, the gene expression involved in lipid metabolism (Scd1, Fabp4, Fas, Cd36, Lpl, and Plin5) was upregulated, while gene expression involved in the pancreatic β-cells function (such as Pdx1, Nkx6.1, Glut2, and Irs-2) was decreased. Gene silencing of JunD reversed the lipotoxic effects induced by PA on β-cells. These results suggested that JunD regulated the function of pancreatic β-cells by altering lipid accumulation.
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Affiliation(s)
- Kexin Wang
- Department of General Surgery, Qilu Hospital of Shandong University, Jinan, China
| | - Yixin Cui
- Department of Endocrinology, Qilu Hospital of Shandong University, Shandong University, Jinan, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, China
| | - Peng Lin
- Department of Endocrinology, Qilu Hospital of Shandong University, Shandong University, Jinan, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, China
| | - Zhina Yao
- Center for Reproductive Medicine, Cheeloo College of Medicine, Shandong University, Jinan, China
- *Correspondence: Zhina Yao, ; Yu Sun,
| | - Yu Sun
- Department of Endocrinology, Qilu Hospital of Shandong University, Shandong University, Jinan, China
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, China
- *Correspondence: Zhina Yao, ; Yu Sun,
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Townsend LK, Brunetta HS, Mori MAS. Mitochondria-associated ER membranes in glucose homeostasis and insulin resistance. Am J Physiol Endocrinol Metab 2020; 319:E1053-E1060. [PMID: 32985254 DOI: 10.1152/ajpendo.00271.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Obesity and insulin resistance (IR) are associated with endoplasmic reticulum (ER) stress and mitochondrial dysfunction in several tissues. Although for many years mitochondrial and ER function were studied separately, these organelles also connect to produce interdependent functions. Communication occurs at mitochondria-associated ER membranes (MAMs) and regulates lipid and calcium homeostasis, apoptosis, and the exchange of adenine nucleotides, among other things. Recent evidence suggests that MAMs contribute to organelle, cellular, and systemic metabolism. In obesity and IR models, metabolic tissues such as the liver, skeletal muscle, pancreas, and adipose tissue present alterations in MAM structure or function. The purpose of this mini review is to highlight the MAM disruptions that occur in each tissue during obesity and IR and its relationship with glucose homeostasis and IR. We also discuss the current controversy that surrounds MAMs' role in the development of IR.
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Affiliation(s)
- Logan K Townsend
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, Brazil
| | - Marcelo A S Mori
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas, Brazil
- Obesity and Comorbidities Research Center, University of Campinas, Campinas, Brazil
- Experimental Medicine Research Cluster, University of Campinas, Campinas, Brazil
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Dia M, Gomez L, Thibault H, Tessier N, Leon C, Chouabe C, Ducreux S, Gallo-Bona N, Tubbs E, Bendridi N, Chanon S, Leray A, Belmudes L, Couté Y, Kurdi M, Ovize M, Rieusset J, Paillard M. Reduced reticulum-mitochondria Ca 2+ transfer is an early and reversible trigger of mitochondrial dysfunctions in diabetic cardiomyopathy. Basic Res Cardiol 2020; 115:74. [PMID: 33258101 PMCID: PMC7704523 DOI: 10.1007/s00395-020-00835-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/13/2020] [Indexed: 12/17/2022]
Abstract
Type 2 diabetic cardiomyopathy features Ca2+ signaling abnormalities, notably an altered mitochondrial Ca2+ handling. We here aimed to study if it might be due to a dysregulation of either the whole Ca2+ homeostasis, the reticulum-mitochondrial Ca2+ coupling, and/or the mitochondrial Ca2+ entry through the uniporter. Following a 16-week high-fat high-sucrose diet (HFHSD), mice developed cardiac insulin resistance, fibrosis, hypertrophy, lipid accumulation, and diastolic dysfunction when compared to standard diet. Ultrastructural and proteomic analyses of cardiac reticulum-mitochondria interface revealed tighter interactions not compatible with Ca2+ transport in HFHSD cardiomyocytes. Intramyocardial adenoviral injections of Ca2+ sensors were performed to measure Ca2+ fluxes in freshly isolated adult cardiomyocytes and to analyze the direct effects of in vivo type 2 diabetes on cardiomyocyte function. HFHSD resulted in a decreased IP3R-VDAC interaction and a reduced IP3-stimulated Ca2+ transfer to mitochondria, with no changes in reticular Ca2+ level, cytosolic Ca2+ transients, and mitochondrial Ca2+ uniporter function. Disruption of organelle Ca2+ exchange was associated with decreased mitochondrial bioenergetics and reduced cell contraction, which was rescued by an adenovirus-mediated expression of a reticulum-mitochondria linker. An 8-week diet reversal was able to restore cardiac insulin signaling, Ca2+ transfer, and cardiac function in HFHSD mice. Therefore, our study demonstrates that the reticulum-mitochondria Ca2+ miscoupling may play an early and reversible role in the development of diabetic cardiomyopathy by disrupting primarily the mitochondrial bioenergetics. A diet reversal, by counteracting the MAM-induced mitochondrial Ca2+ dysfunction, might contribute to restore normal cardiac function and prevent the exacerbation of diabetic cardiomyopathy.
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Affiliation(s)
- Maya Dia
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France.,Laboratory of Experimental and Clinical Pharmacology, Faculty of Sciences, Lebanese University-Beirut, Beirut, Lebanon
| | - Ludovic Gomez
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Helene Thibault
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France.,IHU OPERA, Hospices Civils de Lyon, 69500, Bron, France
| | - Nolwenn Tessier
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Christelle Leon
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Christophe Chouabe
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Sylvie Ducreux
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Noelle Gallo-Bona
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France
| | - Emily Tubbs
- Laboratoire CarMeN-Équipe 3, INSERM, INRA, Université Claude Bernard Lyon-1, INSA Lyon, Univ-Lyon, 69921, Oullins, France
| | - Nadia Bendridi
- Laboratoire CarMeN-Équipe 3, INSERM, INRA, Université Claude Bernard Lyon-1, INSA Lyon, Univ-Lyon, 69921, Oullins, France
| | - Stephanie Chanon
- Laboratoire CarMeN-Équipe 3, INSERM, INRA, Université Claude Bernard Lyon-1, INSA Lyon, Univ-Lyon, 69921, Oullins, France
| | - Aymeric Leray
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne Franche Comté, 21078, Dijon, France
| | - Lucid Belmudes
- Univ. Grenoble Alpes, CEA, Inserm, IRIG, BGE, 38000, Grenoble, France
| | - Yohann Couté
- Univ. Grenoble Alpes, CEA, Inserm, IRIG, BGE, 38000, Grenoble, France
| | - Mazen Kurdi
- Laboratory of Experimental and Clinical Pharmacology, Faculty of Sciences, Lebanese University-Beirut, Beirut, Lebanon
| | - Michel Ovize
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France.,IHU OPERA, Hospices Civils de Lyon, 69500, Bron, France
| | - Jennifer Rieusset
- Laboratoire CarMeN-Équipe 3, INSERM, INRA, Université Claude Bernard Lyon-1, INSA Lyon, Univ-Lyon, 69921, Oullins, France
| | - Melanie Paillard
- Laboratoire CarMeN-Équipe 5 Cardioprotection, INSERM, INRA, Université Claude Bernard Lyon-1, INSA-Lyon, Univ-Lyon, U1060 CARMEN, Equipe 5- Cardioprotection, Groupement Hospitalier Est, Bâtiment B13, 59 boulevard Pinel, 69500, Bron, France.
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Mitochondrial Carriers Regulating Insulin Secretion Profiled in Human Islets upon Metabolic Stress. Biomolecules 2020; 10:biom10111543. [PMID: 33198243 PMCID: PMC7697104 DOI: 10.3390/biom10111543] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/28/2020] [Accepted: 11/10/2020] [Indexed: 12/27/2022] Open
Abstract
Chronic exposure of β-cells to nutrient-rich metabolic stress impairs mitochondrial metabolism and its coupling to insulin secretion. We exposed isolated human islets to different metabolic stresses for 3 days: 0.4 mM oleate or 0.4 mM palmitate at physiological 5.5 mM glucose (lipotoxicity), high 25 mM glucose (glucotoxicity), and high 25 mM glucose combined with 0.4 mM oleate and/or palmitate (glucolipotoxicity). Then, we profiled the mitochondrial carriers and associated genes with RNA-Seq. Diabetogenic conditions, and in particular glucotoxicity, increased expression of several mitochondrial solute carriers in human islets, such as the malate carrier DIC, the α-ketoglutarate-malate exchanger OGC, and the glutamate carrier GC1. Glucotoxicity also induced a general upregulation of the electron transport chain machinery, while palmitate largely counteracted this effect. Expression of different components of the TOM/TIM mitochondrial protein import system was increased by glucotoxicity, whereas glucolipotoxicity strongly upregulated its receptor subunit TOM70. Expression of the mitochondrial calcium uniporter MCU was essentially preserved by metabolic stresses. However, glucotoxicity altered expression of regulatory elements of calcium influx as well as the Na+/Ca2+ exchanger NCLX, which mediates calcium efflux. Overall, the expression profile of mitochondrial carriers and associated genes was modified by the different metabolic stresses exhibiting nutrient-specific signatures.
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Vecellio Reane D, Rizzuto R, Raffaello A. The ER-mitochondria tether at the hub of Ca2+ signaling. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Raghavan S, Malayaperumal S, Mohan V, Balasubramanyam M. A comparative study on the cellular stressors in mesenchymal stem cells (MSCs) and pancreatic β-cells under hyperglycemic milieu. Mol Cell Biochem 2020; 476:457-469. [PMID: 32997307 DOI: 10.1007/s11010-020-03922-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/19/2020] [Indexed: 12/30/2022]
Abstract
β-cell dysfunction is a critical determinant for both type 1 diabetes and type 2 diabetes and β-cells are shown to be highly susceptible to cellular stressors. Mesenchymal stem cells (MSCs) on the other hand are known to have immunomodulatory potential and preferred in clinical applications. However, there is paucity of a comparative study on these cells in relation to several cellular stressors in response to hyperglycemia and this forms the rationale for the present study. INS1 β-cells and MSCs were subjected to high-glucose treatment without and with Metformin, Lactoferrin, or TUDCA and assessed for stress signaling alterations using gene expression, protein expression, as well as functional read-outs. Compared to the untreated control cells, INS1 β-cells or MSCs treated with high glucose showed significant increase in mRNA expressions of ER stress, senescence, and proinflammation. This was accompanied by increased miR146a target genes and decreased levels of SIRT1, NRF2, and miR146a in both the cell types. Consistent with the mRNA results, protein expression levels do reflect the same alterations. Notably, the alterations are relatively less extent in MSCs compared to INS1 β-cells. Interestingly, three different agents, viz., Metformin, Lactoferrin, or TUDCA, were found to overcome the high glucose-induced cellular stresses in a concerted and inter-linked way and restored the proliferation and migration capacity in MSCs as well as normalized the glucose-stimulated insulin secretion in INS1 β-cells. While our study gives a directionality for potential supplementation of metformin/lactoferrin/TUDCA in optimization protocols of MSCs, we suggest that in vitro preconditioning of MSCs with such factors should be further explored with in-depth investigations to harness and enhance the therapeutic capacity/potential of MSCs.
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Affiliation(s)
- Srividhya Raghavan
- Department of Cell and Molecular Biology, Dr. Mohan's Diabetes Specialties Centre, ICMR- Centre for Advanced Research On Diabetes, Madras Diabetes Research Foundation, Gopalapuram, Chennai, 600 086, India
| | - Sarubala Malayaperumal
- Department of Cell and Molecular Biology, Dr. Mohan's Diabetes Specialties Centre, ICMR- Centre for Advanced Research On Diabetes, Madras Diabetes Research Foundation, Gopalapuram, Chennai, 600 086, India
| | - Viswanathan Mohan
- Department of Cell and Molecular Biology, Dr. Mohan's Diabetes Specialties Centre, ICMR- Centre for Advanced Research On Diabetes, Madras Diabetes Research Foundation, Gopalapuram, Chennai, 600 086, India
| | - Muthuswamy Balasubramanyam
- Department of Cell and Molecular Biology, Dr. Mohan's Diabetes Specialties Centre, ICMR- Centre for Advanced Research On Diabetes, Madras Diabetes Research Foundation, Gopalapuram, Chennai, 600 086, India. .,Medical and Health Sciences (MHS), SRM Institute of Science and Technology (SRMIST), SRM Nagar, Kattankulathur, Kanchipuram, Chennai, 603 203, India.
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Mili M, Panthu B, Madec AM, Berger MA, Rautureau GJP, Elena-Herrmann B. Fast and ergonomic extraction of adherent mammalian cells for NMR-based metabolomics studies. Anal Bioanal Chem 2020; 412:5453-5463. [PMID: 32556564 DOI: 10.1007/s00216-020-02764-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/08/2020] [Accepted: 06/08/2020] [Indexed: 11/29/2022]
Abstract
Cellular metabolomics has become key to elucidate mechanistic aspects in various fields such as cancerology or pharmacology, and is rapidly becoming a standard phenotyping tool accessible to the broad biological community. Acquisition of reliable spectroscopic datasets, such as nuclear magnetic resonance (NMR) spectra, to characterize biological systems depends on the elaboration of robust methods for cellular metabolites extraction. Previous studies have addressed many issues raised by these protocols, however with little pondering on ergonomic and practical aspects of the methods that impact their scalability, reproducibility and hence their suitability to high-throughput studies or their use by non-metabolomics experts. Here, we optimize a fast and ergonomic protocol for extraction of metabolites from adherent mammalian cells for NMR metabolomics studies. The proposed extraction protocol, including cell washing, metabolism quenching and actual extraction of intracellular metabolites, was first optimized on HeLa cells. Efficiency of the protocol, in its globality and for the different individual steps, was assessed by NMR quantification of 27 metabolites from cellular extracts. We show that a single PBS wash provides a seemly compromise between contamination from growth medium and leakage of intracellular metabolites. In HeLa cells, extraction using pure methanol, without cell scraping, recovered a higher amount of intracellular metabolites than the reference methanol/water/chloroform method with cell scraping, with yields varying across metabolite classes. Optimized and reference protocols were further tested on eight cell lines of miscellaneous nature, and inter-operator reproducibility was demonstrated. Our results stress the need for tailored extraction protocols and show that fast protocols minimizing time-consuming steps, without compromising extraction yields, are suitable for high-throughput metabolomics studies. Graphical abstract.
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Affiliation(s)
- Manhal Mili
- Institut des Sciences Analytiques UMR 5280, CRMN FRE 2034, Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 rue de la Doua, 69100, Villeurbanne, France
| | - Baptiste Panthu
- CarMeN laboratory, Univ Lyon, INSERM, INRA, INSA, Université Claude Bernard Lyon1, 69121, Oullins, France
| | - Anne-Marie Madec
- CarMeN laboratory, Univ Lyon, INSERM, INRA, INSA, Université Claude Bernard Lyon1, 69121, Oullins, France
| | - Marie-Agnès Berger
- CarMeN laboratory, Univ Lyon, INSERM, INRA, INSA, Université Claude Bernard Lyon1, 69121, Oullins, France
| | - Gilles J P Rautureau
- Institut des Sciences Analytiques UMR 5280, CRMN FRE 2034, Univ Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 rue de la Doua, 69100, Villeurbanne, France
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Genetic locus responsible for diabetic phenotype in the insulin hyposecretion (ihs) mouse. PLoS One 2020; 15:e0234132. [PMID: 32502168 PMCID: PMC7274380 DOI: 10.1371/journal.pone.0234132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/19/2020] [Indexed: 12/30/2022] Open
Abstract
Diabetic animal models have made significant contributions to understanding the etiology of diabetes and to the development of new medications. Our research group recently developed a novel diabetic mouse strain, the insulin hyposecretion (ihs)mouse. The strain involves neither obesity nor insulitis but exhibits notable pancreatic β-cell dysfunction, distinguishing it from other well-characterized animal models. In ihs mice, severe impairment of insulin secretion from pancreas has been elicited by glucose or potassium chloride stimulation. To clarify the genetic basis of impaired insulin secretion, beginning with identifying the causative gene, genetic linkage analysis was performed using [(C57BL/6 × ihs) F1 × ihs] backcross progeny. Genetic linkage analysis and quantitative trait loci analysis for blood glucose after oral glucose loading indicated that a recessively acting locus responsible for impaired glucose tolerance was mapped to a 14.9-Mb region of chromosome 18 between D18Mit233 and D18Mit235 (the ihs locus). To confirm the gene responsible for the ihs locus, a congenic strain harboring the ihs locus on the C57BL/6 genetic background was developed. Phenotypic analysis of B6.ihs-(D18Mit233-D18Mit235) mice showed significant glucose tolerance impairment and markedly lower plasma insulin levels during an oral glucose tolerance test. Whole-genome sequencing and Sanger sequencing analyses on the ihs genome detected two ihs-specific variants changing amino acids within the ihs locus; both variants in Slc25a46 and Tcerg1 were predicted to disrupt the protein function. Based on information regarding gene functions involving diabetes mellitus and insulin secretion, reverse-transcription quantitative polymerase chain reaction analysis revealed that the relative abundance of Reep2 and Sil1 transcripts from ihs islets was significantly decreased whereas that of Syt4 transcripts were significantly increased compared with those of control C57BL/6 mice. Thus, Slc25a46, Tcerg1, Syt4, Reep2 and Sil1 are potential candidate genes for the ihs locus. This will be the focus of future studies in both mice and humans.
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Zung N, Schuldiner M. New horizons in mitochondrial contact site research. Biol Chem 2020; 401:793-809. [PMID: 32324151 DOI: 10.1515/hsz-2020-0133] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/14/2020] [Indexed: 12/18/2022]
Abstract
Contact sites, areas where two organelles are held in close proximity through the action of molecular tethers, enable non-vesicular communication between compartments. Mitochondria have been center stage in the contact site field since the discovery of the first contact between mitochondria and the endoplasmic reticulum (ER) over 60 years ago. However, only now, in the last decade, has there been a burst of discoveries regarding contact site biology in general and mitochondrial contacts specifically. The number and types of characterized contacts increased dramatically, new molecular mechanisms enabling contact formation were discovered, additional unexpected functions for contacts were shown, and their roles in cellular and organismal physiology were emphasized. Here, we focus on mitochondria as we highlight the most recent developments, future goals and unresolved questions in the field.
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Affiliation(s)
- Naama Zung
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
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Zhang XM, Wang YZ, Tong JD, Ning XC, Zhou FQ, Yang XH, Jin HM. Pyruvate alleviates high glucose-induced endoplasmic reticulum stress and apoptosis in HK-2 cells. FEBS Open Bio 2020; 10:827-834. [PMID: 32150786 PMCID: PMC7193158 DOI: 10.1002/2211-5463.12834] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/27/2020] [Accepted: 03/06/2020] [Indexed: 12/24/2022] Open
Abstract
Endoplasmic reticulum (ER) stress plays a critical role in the development of diabetic nephropathy (DN). We previously demonstrated that pyruvate (Pyr)-enriched oral rehydration solution improved glucometabolic disorders and ameliorated DN outcome in db/db mice. Here, we investigated the effects of Pyr on high glucose-induced ER stress and apoptosis in HK-2 cells. Our results suggest that high glucose can induce reactive oxygen species production, apoptosis and ER stress in HK-2 cells, and that Pyr treatment can ameliorate these effects and restore the expression of key proteins involved in ER stress. Thus, Pyr may have potential for the development of novel strategies for the prevention and treatment of clinical DN.
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Affiliation(s)
- Xiao Meng Zhang
- Department of NephrologyPudong Medical CenterShanghai Pudong HospitalFudan UniversityShanghaiChina
| | - Yi Zhen Wang
- Department of Clinical MedicineAffiliated Hospital of Qingdao UniversityShandongChina
| | - Jin Dong Tong
- Division of Vascular SurgeryPudong Medical CenterShanghai Pudong HospitalFudan UniversityShanghaiChina
| | - Xu Chao Ning
- Department of Clinical MedicineAffiliated Hospital of Qingdao UniversityShandongChina
| | - Fang Qiang Zhou
- Shanghai Sandai Pharmaceutical R&D Co., Ltd.PudongChina
- Present address:
US officeLas VegasNVUSA
| | - Xiu Hong Yang
- Department of NephrologyPudong Medical CenterShanghai Pudong HospitalFudan UniversityShanghaiChina
| | - Hui Min Jin
- Department of NephrologyPudong Medical CenterShanghai Pudong HospitalFudan UniversityShanghaiChina
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Idevall-Hagren O, Tengholm A. Metabolic regulation of calcium signaling in beta cells. Semin Cell Dev Biol 2020; 103:20-30. [PMID: 32085965 DOI: 10.1016/j.semcdb.2020.01.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/10/2020] [Accepted: 01/28/2020] [Indexed: 12/22/2022]
Abstract
The cytoplasmic Ca2+ concentration ([Ca2+]cyt) regulates a vast number of cellular functions, including insulin secretion from beta cells. The major physiological insulin secretagogue, glucose, triggers [Ca2+]cyt oscillations in beta cells. Synchronization of the oscillations among the beta cells within an islet underlies the generation of pulsatile insulin secretion. This review describes the mechanisms generating [Ca2+]cyt oscillations, the interactions between [Ca2+]cyt and cell metabolism, as well as the contribution of various organelles to the shaping of [Ca2+]cyt signals and insulin secretion. It also discusses how Ca2+ signals are coordinated and spread throughout the islets and data indicating that altered Ca2+ signaling is associated with beta cell dysfunction and development of type 2 diabetes.
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Affiliation(s)
- Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden.
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Esch N, Jo S, Moore M, Alejandro EU. Nutrient Sensor mTOR and OGT: Orchestrators of Organelle Homeostasis in Pancreatic β-Cells. J Diabetes Res 2020; 2020:8872639. [PMID: 33457426 PMCID: PMC7787834 DOI: 10.1155/2020/8872639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/06/2020] [Accepted: 11/24/2020] [Indexed: 02/08/2023] Open
Abstract
The purpose of this review is to integrate the role of nutrient-sensing pathways into β-cell organelle dysfunction prompted by nutrient excess during type 2 diabetes (T2D). T2D encompasses chronic hyperglycemia, hyperlipidemia, and inflammation, which each contribute to β-cell failure. These factors can disrupt the function of critical β-cell organelles, namely, the ER, mitochondria, lysosomes, and autophagosomes. Dysfunctional organelles cause defects in insulin synthesis and secretion and activate apoptotic pathways if homeostasis is not restored. In this review, we will focus on mTORC1 and OGT, two major anabolic nutrient sensors with important roles in β-cell physiology. Though acute stimulation of these sensors frequently improves β-cell function and promotes adaptation to cell stress, chronic and sustained activity disturbs organelle homeostasis. mTORC1 and OGT regulate organelle function by influencing the expression and activities of key proteins, enzymes, and transcription factors, as well as by modulating autophagy to influence clearance of defective organelles. In addition, mTORC1 and OGT activity influence islet inflammation during T2D, which can further disrupt organelle and β-cell function. Therapies for T2D that fine-tune the activity of these nutrient sensors have yet to be developed, but the important role of mTORC1 and OGT in organelle homeostasis makes them promising targets to improve β-cell function and survival.
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Affiliation(s)
- Nicholas Esch
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Seokwon Jo
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mackenzie Moore
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Surgery, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Emilyn U. Alejandro
- Department of Integrative Biology & Physiology, University of Minnesota Medical School, University of Minnesota, Minneapolis, Minnesota, USA
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Tao L, Huang X, Xu M, Yang L, Hua F. MiR-144 protects the heart from hyperglycemia-induced injury by regulating mitochondrial biogenesis and cardiomyocyte apoptosis. FASEB J 2019; 34:2173-2197. [PMID: 31907983 DOI: 10.1096/fj.201901838r] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/25/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022]
Abstract
Several lines of evidence have revealed the potential of microRNAs (miRNAs, miRs) as biomarkers for detecting diabetic cardiomyopathy, although their functions in hyperglycemic cardiac dysfunction are still lacking. In this study, mitochondrial biogenesis was markedly impaired induced by high glucose (HG), as evidenced by dysregulated mitochondrial structure, reduced mitochondrial DNA contents, and biogenesis-related mRNA levels, accompanied by increased cell apoptosis. MiR-144 was identified to be decreased in HG-induced cardiomyocytes and in streptozotocin (STZ)-challenged heart samples. Forced miR-144 expression enhanced mitochondrial biogenesis and suppressed cell apoptosis, while miR-144 inhibition exhibited the opposite results. Rac-1 was identified as a target gene of miR-144. Decreased Rac-1 levels activated AMPK phosphorylation and PGC-1α deacetylation, leading to increased mitochondrial biogenesis and reduced cell apoptosis. Importantly, the systemic neutralization of miR-144 attenuated mitochondrial disorder and ventricular dysfunction following STZ treatment. Additionally, plasma miR-144 decreased markedly in diabetic patients with cardiac dysfunction. The receiver-operator characteristic curve showed that plasma miR-144 could specifically predict diabetic patients developing cardiac dysfunction. In conclusion, this study provides strong evidence suggesting that miR-144 protects heart from hyperglycemia-induced injury by improving mitochondrial biogenesis and decreasing cell apoptosis via targeting Rac-1. Forced miR-144 expression might, thus, be a protective strategy for treating hyperglycemia-induced cardiac dysfunction.
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Affiliation(s)
- Lichan Tao
- Department of Cardiology, The Third Affiliated Hospital of Soochow University, Changzhou City, China
| | - Xiaoli Huang
- Department of Endocrinology, The Third Affiliated Hospital of Soochow University, Changzhou City, China
| | - Min Xu
- Department of Echocardiography, The Third Affiliated Hospital of Soochow University, Changzhou City, China
| | - Ling Yang
- Department of Cardiology, The Third Affiliated Hospital of Soochow University, Changzhou City, China
| | - Fei Hua
- Department of Endocrinology, The Third Affiliated Hospital of Soochow University, Changzhou City, China
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The role of mitochondria-associated membranes in cellular homeostasis and diseases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 350:119-196. [PMID: 32138899 DOI: 10.1016/bs.ircmb.2019.11.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondria and endoplasmic reticulum (ER) are fundamental in the control of cell physiology regulating several signal transduction pathways. They continuously communicate exchanging messages in their contact sites called MAMs (mitochondria-associated membranes). MAMs are specific microdomains acting as a platform for the sorting of vital and dangerous signals. In recent years increasing evidence reported that multiple scaffold proteins and regulatory factors localize to this subcellular fraction suggesting MAMs as hotspot signaling domains. In this review we describe the current knowledge about MAMs' dynamics and processes, which provided new correlations between MAMs' dysfunctions and human diseases. In fact, MAMs machinery is strictly connected with several pathologies, like neurodegeneration, diabetes and mainly cancer. These pathological events are characterized by alterations in the normal communication between ER and mitochondria, leading to deep metabolic defects that contribute to the progression of the diseases.
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47
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Roma LP, Jonas JC. Nutrient Metabolism, Subcellular Redox State, and Oxidative Stress in Pancreatic Islets and β-Cells. J Mol Biol 2019; 432:1461-1493. [PMID: 31634466 DOI: 10.1016/j.jmb.2019.10.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/25/2019] [Accepted: 10/10/2019] [Indexed: 01/01/2023]
Abstract
Insulin-secreting pancreatic β-cells play a critical role in blood glucose homeostasis and the development of type 2 diabetes (T2D) in the context of insulin resistance. Based on data obtained at the whole cell level using poorly specific chemical probes, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide have been proposed to contribute to the stimulation of insulin secretion by nutrients (positive role) and to the alterations of cell survival and secretory function in T2D (negative role). This raised the controversial hypothesis that any attempt to decrease β-cell oxidative stress and apoptosis in T2D would further impair insulin secretion. Over the last decade, the development of genetically-encoded redox probes that can be targeted to cellular compartments of interest and are specific of redox couples allowed the evaluation of short- and long-term effects of nutrients on β-cell redox changes at the subcellular level. The data indicated that the nutrient regulation of β-cell redox signaling and ROS toxicity is far more complex than previously thought and that the subcellular compartmentation of these processes cannot be neglected when evaluating the mechanisms of ROS production or the efficacy of antioxidant enzymes and antioxidant drugs under glucolipotoxic conditions and in T2D. In this review, we present what is currently known about the compartmentation of redox homeostatic systems and tools to investigate it. We then review data about the effects of nutrients on β-cell subcellular redox state under normal conditions and in the context of T2D and discuss challenges and opportunities in the field.
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Affiliation(s)
- Leticia P Roma
- Universität des Saarlandes, Biophysics Department, Center for Human and Molecular Biology, Kirbergerstrasse Building 48, 66421, Homburg/Saar, Germany
| | - Jean-Christophe Jonas
- Université Catholique de Louvain, Institute of Experimental and Clinical Research, Pole of Endocrinology, Diabetes and Nutrition, Avenue Hippocrate 55 (B1.55.06), B-1200 Brussels, Belgium.
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