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Zhang C, Li S, Li L, Wang R, Luo S, Li G. Stevioside Ameliorates Palmitic Acid-Induced Abnormal Glucose Uptake via the PDK4/AMPK/TBC1D1 Pathway in C2C12 Myotubes. Endocrinol Diabetes Metab 2024; 7:e00482. [PMID: 38556697 PMCID: PMC10982459 DOI: 10.1002/edm2.482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/04/2024] [Accepted: 03/05/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Stevioside (SV) with minimal calories is widely used as a natural sweetener in beverages due to its high sweetness and safety. However, the effects of SV on glucose uptake and the pyruvate dehydrogenase kinase isoenzyme (PDK4) as an important protein in the regulation of glucose metabolism, remain largely unexplored. In this study, we used C2C12 skeletal muscle cells that was induced by palmitic acid (PA) to assess the effects and mechanisms of SV on glucose uptake and PDK4. METHODS The glucose uptake of C2C12 cells was determined by 2-NBDG; expression of the Pdk4 gene was measured by quantitative real-time PCR; and expression of the proteins PDK4, p-AMPK, TBC1D1 and GLUT4 was assessed by Western blotting. RESULTS In PA-induced C2C12 myotubes, SV could significantly promote cellular glucose uptake by decreasing PDK4 levels and increasing p-AMPK and TBC1D1 levels. SV could promote the translocation of GLUT4 from the cytoplasm to the cell membrane in cells. Moreover, in Pdk4-overexpressing C2C12 myotubes, SV decreased the level of PDK4 and increased the levels of p-AMPK and TBC1D1. CONCLUSION SV was found to ameliorate PA-induced abnormal glucose uptake via the PDK4/AMPK/TBC1D1 pathway in C2C12 myotubes. Although these results warranted further investigation for validation, they may provide some evidence of SV as a safe natural sweetener for its use in sugar-free beverages to prevent and control T2DM.
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Affiliation(s)
- Changfa Zhang
- Center for Clinical Epidemiology and Methodology (CCEM)Guangdong Second Provincial General HospitalGuangzhouChina
| | - Shuai Li
- Center for Clinical Epidemiology and Methodology (CCEM)Guangdong Second Provincial General HospitalGuangzhouChina
| | - Likang Li
- Center for Clinical Epidemiology and Methodology (CCEM)Guangdong Second Provincial General HospitalGuangzhouChina
| | - Ruoting Wang
- Center for Clinical Epidemiology and Methodology (CCEM)Guangdong Second Provincial General HospitalGuangzhouChina
| | - Shiming Luo
- Fertility Preservation Lab, Guangdong‐Hong Kong Metabolism and Reproduction Joint Laboratory, Reproductive Medicine CenterGuangdong Second Provincial General HospitalGuangzhouChina
| | - Guowei Li
- Center for Clinical Epidemiology and Methodology (CCEM)Guangdong Second Provincial General HospitalGuangzhouChina
- Department of Health Research Methods, Evidence, and Impact (HEI)McMaster UniversityHamiltonOntarioCanada
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Ly HT, Pham KD, Le PH, Do THT, Nguyen TTH, Le VM. Pharmacological properties of Ensete glaucum seed extract: Novel insights for antidiabetic effects via modulation of oxidative stress, inflammation, apoptosis and MAPK signaling pathways. JOURNAL OF ETHNOPHARMACOLOGY 2024; 320:117427. [PMID: 37992883 DOI: 10.1016/j.jep.2023.117427] [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: 10/04/2023] [Revised: 11/06/2023] [Accepted: 11/12/2023] [Indexed: 11/24/2023]
Abstract
ETHNOPHAMACOLOGICAL RELEVANCE Medicinal plants are increasingly making important contributions to diabetic treatment. Ensete glaucum seeds have been widely used in folk medicine to treat diabetes. AIM OF THE STUDY The study was aimed to investigate the protective effect and active mechanisms of E. glaucum seed extract (EGSE) against streptozotocin (STZ)-induced hyperglycemia. MATERIALS AND METHODS Hyperglycemic mice were treated with EGSE (25 and 50 mg/kg) or glibenclamide (5 mg/kg) once daily for 7 d. The effects of these treatments on changes in blood biochemical parameters, pancreatic, liver, and kidney histopathology, oxidative stress and inflammatory marker levels in pancreatic, hepatic, and renal tissues were assessed. Expression of several proteins in MAPK signaling pathway related to apoptosis in pancreatic tissue were investigated. Furthermore, ex vivo, in vitro, and in silico biological activities of EGSE and its compounds were also examined. RESULTS EGSE and glibenclamide increased notably insulin, reduced significantly glucose, AST, ALT, BUN and creatinine levels in blood. Pancreatic islets, hepatic and renal tissue structure were restored by EGSE or glibenclamide. EGSE showed significant anti-oxidative stress and anti-inflammatory effects by enhancing GSH level and dropping MDA, NF-κB, TNF-α and IL-6 levels in these tissues. Particularly, EGSE exhibited pancreatic protective effect against STZ-induced apoptosis through the MAPK signaling pathway by down-regulation of p-p38 MAPK, ERK1/2, JNK1, p-AMPK, Bax, Bax/Bcl-2, cytochrome c, cleaved-caspase 3 and PARP expression, and slight up-regulation of Bcl-2 expression. Moreover, EGSE inhibited intestinal glucose absorption, PTP1B, α-amylase, and α-glucosidase activities. Its isolated compounds (Afzelechin and coniferaldehyde) showed PTP1B and α-glucosidase inhibitory activities, and potent structure-activity relationships. CONCLUSION These findings indicated the hypoglycemic and protective effects of E. glaucum seed extract against the STZ diabetogenic action. E. glaucum seed is a potential candidate for further studies to confirm its activities as a therapeutic agent for diabetic patients.
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Affiliation(s)
- Hai Trieu Ly
- National Institute of Medicinal Materials (NIMM), Hanoi, 100000, Viet Nam; Research Center of Ginseng and Medicinal Materials (CGMM), National Institute of Medicinal Materials, Ho Chi Minh City, 700000, Viet Nam.
| | - Khuong Duy Pham
- Research Center of Ginseng and Medicinal Materials (CGMM), National Institute of Medicinal Materials, Ho Chi Minh City, 700000, Viet Nam.
| | - Phung Hien Le
- College of Science and Engineering, Flinders University, Sturt Rd, Bedford Park, South Australia, 5042, Australia.
| | - Thi Hong Tuoi Do
- Department of Pharmacology, Faculty of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, 700000, Viet Nam.
| | - Thi Thu Huong Nguyen
- Faculty of Pharmacy, Hong Bang International University (HIU), Ho Chi Minh City, 700000, Viet Nam.
| | - Van Minh Le
- National Institute of Medicinal Materials (NIMM), Hanoi, 100000, Viet Nam; Research Center of Ginseng and Medicinal Materials (CGMM), National Institute of Medicinal Materials, Ho Chi Minh City, 700000, Viet Nam.
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3
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Mukhuty A, Mandal S, Fouzder C, Das S, Chattopadhyay D, Majumdar T, Kundu R. Nrf2 inhibition regulates intracellular lipid accumulation in mouse insulinoma cells and improves insulin secretory function. Mol Cell Endocrinol 2024; 581:112112. [PMID: 38000461 DOI: 10.1016/j.mce.2023.112112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/11/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023]
Abstract
High amount of fat in the pancreas is linked to poor functioning of β-cells and raises the risk of type 2 diabetes. Here we report the putative role of a circulatory glycoprotein Fetuin-A, a known obesity marker, in promoting lipid accumulation in β-cells and its association with Fatty acid translocase/CD36 for lipid storage culminate in β-cell dysfunction. Additionally, this work reveals regulation of CD36 via Nrf2, a key regulator of oxidative stress, and reduction of lipid accumulation by suppression of Nrf2 that restores β-cell function. Palmitate (0.50 mM) and Fetuin-A (100 μg/mL) exposure showed high levels of intracellular lipid in MIN6 (mouse insulinoma cells) with a concomitant decrease in insulin secretion. This also increased the expression of important lipogenic factors, like CD36, PGC1α, PPARγ, and SREBP1. Flow cytometry analysis of CD36 membrane localization has been corroborated with an increased accumulation of lipids as indicated by Oil-Red-O staining. Immunoblotting and immunofluorescence of Nrf2 indicated its high expression in palmitate-fetuin-A incubation and translocation in the nucleus. Suppression of Nrf2 by siRNA showed a reduced expression of lipogenic genes, ablation of lipid droplets, decrease in the number of apoptotic cells, and restoration of insulin secretion with a corresponding increase of Pdx1, BETA2, and Ins1 gene expression. Our study thus suggested an important aspect of lipid accumulation in the pancreatic β-cells contributing to β-cell dysfunction and demonstrated the role of Fetuin-A in CD36 expression, with a possible way of restoring β-cell function by targeting Nrf2.
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Affiliation(s)
- Alpana Mukhuty
- Cell Signaling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India
| | - Samanwita Mandal
- Cell Signaling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India
| | - Chandrani Fouzder
- Cell Signaling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India
| | - Snehasis Das
- Cellular and Molecular Endocrinology Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India
| | - Dipanjan Chattopadhyay
- Cellular and Molecular Endocrinology Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India
| | - Tanmay Majumdar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Rakesh Kundu
- Cell Signaling Laboratory, Department of Zoology, Visva-Bharati University, Santiniketan, 731 235, India.
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Nguyen JP, Arthur TD, Fujita K, Salgado BM, Donovan MKR, Matsui H, Kim JH, D'Antonio-Chronowska A, D'Antonio M, Frazer KA. eQTL mapping in fetal-like pancreatic progenitor cells reveals early developmental insights into diabetes risk. Nat Commun 2023; 14:6928. [PMID: 37903777 PMCID: PMC10616100 DOI: 10.1038/s41467-023-42560-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 10/13/2023] [Indexed: 11/01/2023] Open
Abstract
The impact of genetic regulatory variation active in early pancreatic development on adult pancreatic disease and traits is not well understood. Here, we generate a panel of 107 fetal-like iPSC-derived pancreatic progenitor cells (iPSC-PPCs) from whole genome-sequenced individuals and identify 4065 genes and 4016 isoforms whose expression and/or alternative splicing are affected by regulatory variation. We integrate eQTLs identified in adult islets and whole pancreas samples, which reveal 1805 eQTL associations that are unique to the fetal-like iPSC-PPCs and 1043 eQTLs that exhibit regulatory plasticity across the fetal-like and adult pancreas tissues. Colocalization with GWAS risk loci for pancreatic diseases and traits show that some putative causal regulatory variants are active only in the fetal-like iPSC-PPCs and likely influence disease by modulating expression of disease-associated genes in early development, while others with regulatory plasticity likely exert their effects in both the fetal and adult pancreas by modulating expression of different disease genes in the two developmental stages.
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Affiliation(s)
- Jennifer P Nguyen
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Biomedical Informatics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Timothy D Arthur
- Department of Biomedical Informatics, University of California, San Diego, La Jolla, CA, 92093, USA
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Kyohei Fujita
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Bianca M Salgado
- Institute of Genomic Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Margaret K R Donovan
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Biomedical Informatics, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Hiroko Matsui
- Institute of Genomic Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Ji Hyun Kim
- Department of Pediatrics, Dongguk University Ilsan Hospital, Goyang, South Korea
| | | | - Matteo D'Antonio
- Department of Biomedical Informatics, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA
- Institute of Genomic Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - Kelly A Frazer
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA.
- Institute of Genomic Medicine, University of California San Diego, 9500 Gilman Dr, La Jolla, CA, 92093, USA.
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Li MY, Liu LZ, Xin Q, Zhou J, Zhang X, Zhang R, Wu Z, Yi J, Dong M. Downregulation of mTORC1 and Mcl-1 by lipid-oversupply contributes to islet β-cell apoptosis and dysfunction. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159332. [PMID: 37196823 DOI: 10.1016/j.bbalip.2023.159332] [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: 12/31/2022] [Revised: 04/22/2023] [Accepted: 04/30/2023] [Indexed: 05/19/2023]
Abstract
Pancreatic β-cell apoptosis is a key feature of diabetes and can be induced by chronic exposure to saturated fatty acids (FAs). However, the underlying mechanisms remain poorly understood. We presently evaluated the role of Mcl-1 and mTOR in mice fed with high-fat-diet (HFD) and β-cells exposed to the overloaded palmitic acid (PA). Compared with normal-chow-diet (NCD)-fed mice, HFD group showed impaired glucose tolerance after two months. Along with the diabetes progression, pancreatic islets first became hypertrophic and then atrophic, the ratio of β-cell:α-cell increased in the islets of four months HFD-fed mice while decreased after six months. This process was accompanied by significantly increased β-cell apoptosis and AMPK activity, and decreased Mcl-1 expression and mTOR activity. Consistently, glucose-induced insulin secretion dropped. In terms of mechanism, PA with lipotoxic dose could activate AMPK, which in turn inhibited ERK-stimulated Mcl-1Thr163 phosphorylation. Meanwhile, AMPK blocked Akt activity to release Akt inhibition on GSK3β, followed by GSK3β-initiated Mcl-1Ser159 phosphorylation. The context of Mcl-1 phosphorylation finally led to its degradation by ubiquitination. Also, AMPK inhibited the activity of mTORC1, resulting in a lower level of Mcl-1. Suppression of mTORC1 activity and Mcl-1 expression positively related to β-cell failure. Alteration of Mcl-1 or mTOR expression rendered different tolerance of β-cell to different dose of PA. In conclusion, lipid oversupply-induced dual modulation of mTORC1 and Mcl-1 finally led to β-cell apoptosis and impaired insulin secretion. The study may help further understand the pathogenesis of β-cell dysfunction in case of dyslipidemia, and provide promising therapeutic targets for diabetes.
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Affiliation(s)
- Ming-Yue Li
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China; GuangZhou Laboratory, No.9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, Guangdong, China
| | - Li-Zhong Liu
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China
| | - Qihang Xin
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China
| | - Jiaying Zhou
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China
| | - Xiaoyang Zhang
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China
| | - Rui Zhang
- GuangZhou Laboratory, No.9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, Guangdong, China
| | - Zangshu Wu
- GuangZhou Laboratory, No.9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, Guangdong, China
| | - Junbo Yi
- Department of Physiology, School of Basic Medical Sciences, Shenzhen University Medical School, Shenzhen University, Shenzhen 518055, Guangdong, China
| | - Ming Dong
- GuangZhou Laboratory, No.9 XingDaoHuanBei Road, Guangzhou International Bio Island, Guangzhou 510005, Guangdong, China.
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Mohammadi-Motlagh HR, Sadeghalvad M, Yavari N, Primavera R, Soltani S, Chetty S, Ganguly A, Regmi S, Fløyel T, Kaur S, Mirza AH, Thakor AS, Pociot F, Yarani R. β Cell and Autophagy: What Do We Know? Biomolecules 2023; 13:biom13040649. [PMID: 37189396 DOI: 10.3390/biom13040649] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 05/17/2023] Open
Abstract
Pancreatic β cells are central to glycemic regulation through insulin production. Studies show autophagy as an essential process in β cell function and fate. Autophagy is a catabolic cellular process that regulates cell homeostasis by recycling surplus or damaged cell components. Impaired autophagy results in β cell loss of function and apoptosis and, as a result, diabetes initiation and progress. It has been shown that in response to endoplasmic reticulum stress, inflammation, and high metabolic demands, autophagy affects β cell function, insulin synthesis, and secretion. This review highlights recent evidence regarding how autophagy can affect β cells' fate in the pathogenesis of diabetes. Furthermore, we discuss the role of important intrinsic and extrinsic autophagy modulators, which can lead to β cell failure.
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Affiliation(s)
- Hamid-Reza Mohammadi-Motlagh
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah 67155-1616, Iran
| | - Mona Sadeghalvad
- Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran 1416634793, Iran
| | - Niloofar Yavari
- Department of Cellular and Molecular Medicine, The Panum Institute, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Rosita Primavera
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Setareh Soltani
- Clinical Research Development Center, Taleghani and Imam Ali Hospital, Kermanshah University of Medical Sciences, Kermanshah 67145-1673, Iran
| | - Shashank Chetty
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Abantika Ganguly
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Shobha Regmi
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Tina Fløyel
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Simranjeet Kaur
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
| | - Aashiq H Mirza
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
- Department of Pharmacology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Avnesh S Thakor
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Flemming Pociot
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
- Institute for Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Reza Yarani
- Interventional Regenerative Innovation at Stanford (IRIS), Department of Radiology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Translational Type 1 Diabetes Research, Department of Clinical Research, Steno Diabetes Center Copenhagen, 2730 Herlev, Denmark
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A Novel 5-Chloro- N-phenyl-1H-indole-2-carboxamide Derivative as Brain-Type Glycogen Phosphorylase Inhibitor: Validation of Target PYGB. Molecules 2023; 28:molecules28041697. [PMID: 36838691 PMCID: PMC9958726 DOI: 10.3390/molecules28041697] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
Brain-type glycogen phosphorylase (PYGB) inhibitors are recognized as prospective drugs for treating ischemic brain injury. We previously reported compound 1 as a novel glycogen phosphorylase inhibitor with brain-protective properties. In this study, we validated whether PYGB could be used as the therapeutic target for hypoxic-ischemic diseases and investigated whether compound 1 exerts a protective effect against astrocyte hypoxia/reoxygenation (H/R) injury by targeting PYGB. A gene-silencing strategy was initially applied to downregulate PYGB proteins in mouse astrocytes, which was followed by a series of cellular experiments with compound 1. Next, we compared relevant indicators that could prove the protective effect of compound 1 on brain injury, finding that after PYGB knockdown, compound 1 could not obviously alleviate astrocytes H/R injury, as evidenced by cell viability, which was not significantly improved, and lactate dehydrogenase (LDH) leakage rate, intracellular glucose content, and post-ischemic reactive oxygen species (ROS) level, which were not remarkably reduced. At the same time, cellular energy metabolism did not improve, and the degree of extracellular acidification was not downregulated after administration of compound 1 after PYGB knockdown. In addition, it could neither significantly increase the level of mitochondrial aerobic energy metabolism nor inhibit the expression of apoptosis-associated proteins. The above results indicate that compound 1 could target PYGB to exert its protective effect against cellular H/R injury in mouse astrocytes. Simultaneously, we further demonstrated that PYGB could be an efficient therapeutic target for ischemic-hypoxic diseases. This study provides a new reference for further in-depth study of the action mechanism of the efficacy of compound 1.
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Shi H, Jiang N, Wei L, Cai J, Zhang W, Jiang Q, Loor JJ, Liu J. AMPK-ChREBP axis mediates de novo milk fatty acid synthesis promoted by glucose in the mammary gland of lactating goats. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2022; 10:234-242. [PMID: 35785250 PMCID: PMC9213698 DOI: 10.1016/j.aninu.2022.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/13/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
To investigate the role of glucose in regulating milk fatty acid synthesis, 6 lactating Guanzhong dairy goats were infused with 0, 60, or 100 g/d glucose via the external pubic artery in a 3 × 3 repeated Latin square experiment. A concomitant in vitro experiment was conducted to investigate possible mechanisms whereby glucose regulates milk fatty acid synthesis. RNA sequencing was used for cellular transcriptome analysis. Drugs, MK-2206, rapamycin, and dorsomorphin were used to block cellular mammalian AMP-activated protein kinase (AMPK), AKT serine/threonine kinase 1, and mechanistic target of rapamycin kinase signaling pathways, respectively. Carbohydrate response element binding protein (ChREBP) was knockdown and overexpressed to investigate its role in regulating milk fatty acid synthesis in mammary epithelial cells. Glucose infusion linearly elevated the concentration of C8:0 (P = 0.039) and C10:0 (P = 0.041) in milk fat while it linearly decreased (P = 0.049) that of C16:0. This result was in agreement with the upregulation of genes related to de novo synthesis of fatty acids and lipid droplet formation, including adipose differentiation-related protein, butyrophilin subfamily 1 member A1, fatty acid synthase (FASN) and ChREBP. Their expression increased (P < 0.05) linearly in the lactating goat mammary gland. In vitro, glucose linearly stimulated the expression of genes related to de novo synthesis of fatty acids and cellular triacylglycerol in cultured mammary epithelial cells. RNA sequencing and inhibition studies revealed that glucose induced transcriptomic changes increasing lipogenic pathways, with AMPK responding to glucose by controlling ChREBP and FASN. Knockdown and overexpression of ChREBP highlighted its essential role in lipogenesis. The knockdown and overexpression of ChREBP protein also revealed an essential role in regulating the de novo synthesis of fatty acids. Collectively, our data highlight that glucose supplementation promotes de novo fatty acid synthesis via the AMPK-ChREBP axis, hence increasing milk fat yield in the goat mammary gland. Results from the current study provide possible strategies to manipulate the fatty acid composition as well as improve ruminant milk quality.
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Affiliation(s)
- Hengbo Shi
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Nannan Jiang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Ling Wei
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Jie Cai
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Wenying Zhang
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Qianming Jiang
- Mammalian Nutrition Physiology Genomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 61801, USA
| | - Juan J. Loor
- Mammalian Nutrition Physiology Genomics, Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, 61801, USA
| | - Jianxin Liu
- Institute of Dairy Science, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
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9
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Qian Z, Mengxun Z, Yingchao W, Tingting Z, Roujuan W, Shuhong W, Yi D, Ruirui Y, Peng Y, Yifan S, Yunshi Z, Xun S, Yaping G, Zhendan H, Tie C, Chenyang L. Natural Compound 2-Chloro-1,3-dimethoxy-5-methylbenzene, Isolated from Hericium Erinaceus, Inhibits Fungal Growth by Disrupting Membranes and Triggering Apoptosis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:6444-6454. [PMID: 35580153 DOI: 10.1021/acs.jafc.2c01417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In this study, 2-chloro-1,3-dimethoxy-5-methylbenzene (CDM), a natural product with anti-Candida albicans activity, was discovered from the Hericium erinaceus mycelium. The minimum inhibitory concentration of CDM was 62.5 μg/mL. Moreover, structural analogues of CDM obtained from chemical synthesis were applied to explore the structure-activity relationship (SAR) of CDM against C. albicans. It was found that methoxy groups, halogen atoms (except fluorine atoms), and methoxy-meta-position methyl groups in the structure of CDM were the key active groups. Furthermore, we investigated the anti-C. albicans mechanism of CDM. Experiments suggested that CDM destroyed the cell membrane of C. albicans, including the cytoplasmic membrane and mitochondrial membrane, and caused the accumulation of reactive oxygen species and mitochondrial dysfunction, which ultimately led to apoptosis of C. albicans. In addition, CDM had no toxicity on human normal gastric mucosal epithelial cells exposed to a concentration of 125 μg/mL. Experiments showed that CDM reduced the damage of C. albicans to the visceral tissue of infected mice and improved the survival rate of mice. Our research provides a scientific basis for the discovery of effective and safe anti-C. albicans drugs from H. erinaceus.
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Affiliation(s)
- Zhang Qian
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Zhang Mengxun
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Wang Yingchao
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Zhen Tingting
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Wang Roujuan
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Wang Shuhong
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Du Yi
- University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Yu Ruirui
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Yi Peng
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Song Yifan
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Zhi Yunshi
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Song Xun
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Guo Yaping
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - He Zhendan
- Guangdong Province Department of Pharmacology, School of Medicine, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Chen Tie
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
| | - Li Chenyang
- Shenzhen University Health Science Center, Shenzhen University, Shenzhen, Guangdong Province 518000, China
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10
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Aharon-Hananel G, Romero-Afrima L, Saada A, Mantzur C, Raz I, Weksler-Zangen S. Cytochrome c Oxidase Activity as a Metabolic Regulator in Pancreatic Beta-Cells. Cells 2022; 11:cells11060929. [PMID: 35326380 PMCID: PMC8946064 DOI: 10.3390/cells11060929] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cells couple glucose-stimulated insulin secretion (GSIS) with oxidative phosphorylation via cytochrome c oxidase (COX), a mitochondrial respiratory-chain enzyme. The Cohen diabetic-sensitive (CDs) rats exhibit hyperglycemia when fed a diabetogenic diet but maintain normoglycemia on a regular diet. We have previously reported a decreased COX activity in CDs rats and explored its relevance for type 2 diabetes (T2D). In this study, we investigated the relation between COX activity in islets, peripheral-blood mononuclear cells (PBMCs), and GSIS during diabetes development in CDs rats fed a diabetogenic diet for 4, 11, 20, and 30 days and during reversion to normoglycemia in hyperglycemic CDs rats fed a reversion diet for 7, 11, and 20 days. An oral glucose-tolerance test was performed at different periods of the diets measuring blood glucose and insulin concentrations. COX activity was determined in islets and PBMCs isolated from rats at the different periods of the diets. We demonstrated a progressive reduction in COX activity in CDs-islets that correlated positively with the decreasing GSIS (R2 = 0.9691, p < 0.001) and inversely with the elevation in blood glucose levels (R2 = 0.8396, p < 0.001). Hyperglycemia was initiated when islet COX activity decreased below 46%. The reversion diet restored >46% of the islet COX activity and GSIS while re-establishing normoglycemia. Interestingly, COX activity in PBMCs correlated significantly with islet COX activity (R2 = 0.8944, p < 0.001). Our data support islet COX activity as a major metabolic regulator of β-cells function. The correlation between COX activity in PBMCs and islets may serve as a noninvasive biomarker to monitor β-cell dysfunction in diabetes.
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Affiliation(s)
- Genya Aharon-Hananel
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Division of Endocrinology, Diabetes and Metabolism, The Chaim Sheba Medical Center, Tel Hashomer, Ramat-Gan 5266202, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Leonor Romero-Afrima
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Ann Saada
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Carmit Mantzur
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
| | - Itamar Raz
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Sarah Weksler-Zangen
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
- The Liver Research Laboratory, Hadassah Medical Center, Jerusalem 9112102, Israel
- Correspondence: ; Tel.: +972-50-5172008
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11
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Ru Y, Zhang Y, Xiang YW, Luo Y, Luo Y, Jiang JS, Song JK, Fei XY, Yang D, Zhang Z, Zhang HP, Liu TY, Yin SY, Li B, Kuai L. Gene set enrichment analysis and ingenuity pathway analysis to identify biomarkers in Sheng-ji Hua-yu formula treated diabetic ulcers. JOURNAL OF ETHNOPHARMACOLOGY 2022; 285:114845. [PMID: 34800645 DOI: 10.1016/j.jep.2021.114845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 11/02/2021] [Accepted: 11/13/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Sheng-ji Hua-yu (SJHY) formula is a Chinese herbal prescription for diabetic ulcers (DUs) treatment, which can accelerate wound reconstruction and shorten the healing time. However, its mechanism role maintains unclear. AIM OF THE STUDY To elucidate the molecular mechanisms of SJHY application on DUs. MATERIALS AND METHODS To begin with, transcriptome sequencing was adopted to identified differentially expression mRNAs among normal ulcers, DUs, and DUs + SJHY treatment in vivo. Liquid chromatography-tandem mass spectrometry was applied for the quality control of SJHY formula. GO and KEGG enrichment analysis were used to identify the mechanisms underlying the therapeutic effect of SJHY formula, and then gene set enrichment analysis and ingenuity pathway analysis were conducted for functional analysis. Further, qPCR detection was performed in vivo for validation. RESULTS SJHY administration could regulate the glucose metabolic process, AMPK and HIF-1 pathway to accelerate healing processes of DUs. Besides, CRHR1, SHH, and GAL were identified as the critical targets, and SLC6A3, GRP, FGF23, and CYP27B1 were considered as the upstream genes of SJHY treatment. Combined with animal experiments, the prediction results were validated in DUs mice model. CONCLUSIONS This study used modular pharmacology analysis to identify the biomarkers of SJHY formula and provide the potential therapeutic targets for DUs treatment as well.
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Affiliation(s)
- Yi Ru
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Ying Zhang
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Yan-Wei Xiang
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Ying Luo
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Yue Luo
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, 200443, China.
| | - Jing-Si Jiang
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Jian-Kun Song
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, 200443, China.
| | - Xiao-Ya Fei
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, 200443, China.
| | - Dan Yang
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Zhan Zhang
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Hui-Ping Zhang
- Shanghai Applied Protein Technology Co.Ltd., 58 Yuanmei Road, Shanghai, 200233, China.
| | - Tai-Yi Liu
- Shanghai Applied Protein Technology Co.Ltd., 58 Yuanmei Road, Shanghai, 200233, China.
| | - Shuang-Yi Yin
- Center for Translational Medicine, Huaihe Hospital of Henan University, Kaifeng, 475001, Henan, China.
| | - Bin Li
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China; Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, 200443, China.
| | - Le Kuai
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China; Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, 201203, China.
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12
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Oberhauser L, Maechler P. Lipid-Induced Adaptations of the Pancreatic Beta-Cell to Glucotoxic Conditions Sustain Insulin Secretion. Int J Mol Sci 2021; 23:324. [PMID: 35008750 PMCID: PMC8745448 DOI: 10.3390/ijms23010324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 12/16/2022] Open
Abstract
Over the last decades, lipotoxicity and glucotoxicity emerged as established mechanisms participating in the pathophysiology of obesity-related type 2 diabetes in general, and in the loss of β-cell function in particular. However, these terms hold various potential biological processes, and it is not clear what precisely they refer to and to what extent they might be clinically relevant. In this review, we discuss the basis and the last advances of research regarding the role of free fatty acids, their metabolic intracellular pathways, and receptor-mediated signaling related to glucose-stimulated insulin secretion, as well as lipid-induced β-cell dysfunction. We also describe the role of chronically elevated glucose, namely, glucotoxicity, which promotes failure and dedifferentiation of the β cell. Glucolipotoxicity combines deleterious effects of exposures to both high glucose and free fatty acids, supposedly provoking synergistic defects on the β cell. Nevertheless, recent studies have highlighted the glycerolipid/free fatty acid cycle as a protective pathway mediating active storage and recruitment of lipids. Finally, we discuss the putative correspondence of the loss of functional β cells in type 2 diabetes with a natural, although accelerated, aging process.
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Affiliation(s)
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, Faculty Diabetes Center, University of Geneva Medical Center, 1206 Geneva, Switzerland;
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13
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Wang W, Zhang C. Targeting β-cell dedifferentiation and transdifferentiation: opportunities and challenges. Endocr Connect 2021; 10:R213-R228. [PMID: 34289444 PMCID: PMC8428079 DOI: 10.1530/ec-21-0260] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/21/2021] [Indexed: 12/02/2022]
Abstract
The most distinctive pathological characteristics of diabetes mellitus induced by various stressors or immune-mediated injuries are reductions of pancreatic islet β-cell populations and activity. Existing treatment strategies cannot slow disease progression; consequently, research to genetically engineer β-cell mimetics through bi-directional plasticity is ongoing. The current consensus implicates β-cell dedifferentiation as the primary etiology of reduced β-cell mass and activity. This review aims to summarize the etiology and proposed mechanisms of β-cell dedifferentiation and to explore the possibility that there might be a time interval from the onset of β-cell dysfunction caused by dedifferentiation to the development of diabetes, which may offer a therapeutic window to reduce β-cell injury and to stabilize functionality. In addition, to investigate β-cell plasticity, we review strategies for β-cell regeneration utilizing genetic programming, small molecules, cytokines, and bioengineering to transdifferentiate other cell types into β-cells; the development of biomimetic acellular constructs to generate fully functional β-cell-mimetics. However, the maturation of regenerated β-cells is currently limited. Further studies are needed to develop simple and efficient reprogramming methods for assembling perfectly functional β-cells. Future investigations are necessary to transform diabetes into a potentially curable disease.
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Affiliation(s)
- Wenrui Wang
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun, People’s Republic of China
| | - Chuan Zhang
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun, People’s Republic of China
- Correspondence should be addressed to C Zhang:
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14
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Eguchi N, Vaziri ND, Dafoe DC, Ichii H. The Role of Oxidative Stress in Pancreatic β Cell Dysfunction in Diabetes. Int J Mol Sci 2021; 22:ijms22041509. [PMID: 33546200 PMCID: PMC7913369 DOI: 10.3390/ijms22041509] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 02/07/2023] Open
Abstract
Diabetes is a chronic metabolic disorder characterized by inappropriately elevated glucose levels as a result of impaired pancreatic β cell function and insulin resistance. Extensive studies have been conducted to elucidate the mechanism involved in the development of β cell failure and death under diabetic conditions such as hyperglycemia, hyperlipidemia, and inflammation. Of the plethora of proposed mechanisms, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and oxidative stress have been shown to play a central role in promoting β cell dysfunction. It has become more evident in recent years that these 3 factors are closely interrelated and importantly aggravate each other. Oxidative stress in particular is of great interest to β cell health and survival as it has been shown that β cells exhibit lower antioxidative capacity. Therefore, this review will focus on discussing factors that contribute to the development of oxidative stress in pancreatic β cells and explore the downstream effects of oxidative stress on β cell function and health. Furthermore, antioxidative capacity of β cells to counteract these effects will be discussed along with new approaches focused on preserving β cells under oxidative conditions.
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Affiliation(s)
- Natsuki Eguchi
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
| | | | - Donald C. Dafoe
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
| | - Hirohito Ichii
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
- Correspondence: ; Tel.: +1-714-456-8590
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15
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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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16
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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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