1
|
Ferrero E, Masini M, Carli M, Moscato S, Beffy P, Vaglini F, Mattii L, Corti A, Scarselli M, Novelli M, De Tata V. Dopamine-Mediated Autocrine Inhibition of Insulin Secretion. Mol Cell Endocrinol 2024:112294. [PMID: 38838763 DOI: 10.1016/j.mce.2024.112294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/15/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024]
Abstract
The aim of the present research was to explore the mechanisms underlying the role of dopamine in the regulation of insulin secretion in beta cells. The effect of dopamine on insulin secretion was investigated on INS 832/13 cell line upon glucose and other secretagogues stimulation. Results show that dopamine significantly inhibits insulin secretion stimulated by both glucose and other secretagogues, while it has no effect on the basal secretion. This effect requires the presence of dopamine during incubation with the various secretagogues. Both electron microscopy and immunohistochemistry indicate that in beta cells the D2 dopamine receptor is localized within the insulin granules. Blocking dopamine entry into the insulin granules by inhibiting the VMAT2 transporter with tetrabenazine causes a significant increase in ROS production. Our results confirm that dopamine plays an important role in the regulation of insulin secretion by pancreatic beta cells through a regulated and precise compartmentalization mechanisms.
Collapse
Affiliation(s)
| | | | | | - Stefania Moscato
- Department of Clinical and Experimental Medicine; Interdepartmental Research Centre "Nutraceuticals and Food for Health"
| | | | | | - Letizia Mattii
- Department of Clinical and Experimental Medicine; Interdepartmental Research Centre "Nutraceuticals and Food for Health"
| | | | | | | | - Vincenzo De Tata
- Department of Translational Research; CIME (Interdepartmental Centre of Electron Microscopy), University of Pisa, Pisa, Italy.
| |
Collapse
|
2
|
Rivera Nieves AM, Wauford BM, Fu A. Mitochondrial bioenergetics, metabolism, and beyond in pancreatic β-cells and diabetes. Front Mol Biosci 2024; 11:1354199. [PMID: 38404962 PMCID: PMC10884328 DOI: 10.3389/fmolb.2024.1354199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/17/2024] [Indexed: 02/27/2024] Open
Abstract
In Type 1 and Type 2 diabetes, pancreatic β-cell survival and function are impaired. Additional etiologies of diabetes include dysfunction in insulin-sensing hepatic, muscle, and adipose tissues as well as immune cells. An important determinant of metabolic health across these various tissues is mitochondria function and structure. This review focuses on the role of mitochondria in diabetes pathogenesis, with a specific emphasis on pancreatic β-cells. These dynamic organelles are obligate for β-cell survival, function, replication, insulin production, and control over insulin release. Therefore, it is not surprising that mitochondria are severely defective in diabetic contexts. Mitochondrial dysfunction poses challenges to assess in cause-effect studies, prompting us to assemble and deliberate the evidence for mitochondria dysfunction as a cause or consequence of diabetes. Understanding the precise molecular mechanisms underlying mitochondrial dysfunction in diabetes and identifying therapeutic strategies to restore mitochondrial homeostasis and enhance β-cell function are active and expanding areas of research. In summary, this review examines the multidimensional role of mitochondria in diabetes, focusing on pancreatic β-cells and highlighting the significance of mitochondrial metabolism, bioenergetics, calcium, dynamics, and mitophagy in the pathophysiology of diabetes. We describe the effects of diabetes-related gluco/lipotoxic, oxidative and inflammation stress on β-cell mitochondria, as well as the role played by mitochondria on the pathologic outcomes of these stress paradigms. By examining these aspects, we provide updated insights and highlight areas where further research is required for a deeper molecular understanding of the role of mitochondria in β-cells and diabetes.
Collapse
Affiliation(s)
- Alejandra María Rivera Nieves
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, United States
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Brian Michael Wauford
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, United States
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Accalia Fu
- Diabetes Center of Excellence, University of Massachusetts Chan Medical School, Worcester, MA, United States
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States
| |
Collapse
|
3
|
Morrish F, Gingras H, Noonan J, Huang L, Sweet IR, Kuok IT, Knoblaugh SE, Hockenbery DM. Mitochondrial diabetes in mice expressing a dominant-negative allele of nuclear respiratory factor-1 ( Nrf1 ) in pancreatic β-cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.22.524153. [PMID: 38014068 PMCID: PMC10680558 DOI: 10.1101/2023.01.22.524153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Genetic polymorphisms in nuclear respiratory factor-1 ( NRF1 ), a key transcriptional regulator of nuclear-encoded mitochondrial proteins, have been linked to diabetes. Homozygous deletion of Nrf1 is embryonic lethal in mice. Our goal was to generate mice with β-cell-specific reduction in NRF1 function to investigate the relationship between NRF1 and diabetes. We report the generation of mice expressing a dominant-negative allele of Nrf1 (DNNRF1) in pancreatic β-cells. Heterozygous transgenic mice had high fed blood glucose levels detected at 3 wks of age, which persisted through adulthood. Plasma insulin levels in DNNRF1 transgenic mice were reduced, while insulin sensitivity remained intact in young animals. Islet size was reduced with increased numbers of apoptotic cells, and insulin content in islets by immunohistochemistry was low. Glucose-stimulated insulin secretion in isolated islets was reduced in DNNRF1-mice, but partially rescued by KCl, suggesting that decreased mitochondrial function contributed to the insulin secretory defect. Electron micrographs demonstrated abnormal mitochondrial morphology in β- cells. Expression of NRF1 target genes Tfam , T@1m and T@2m , and islet cytochrome c oxidase and succinate dehydrogenase activities were reduced in DNNRF1-mice. Rescue of mitochondrial function with low level activation of transgenic c-Myc in β-cells was sufficient to restore β-cell mass and prevent diabetes. This study demonstrates that reduced NRF1 function can lead to loss of β-cell function and establishes a model to study the interplay between regulators of bi- genomic gene transcription in diabetes.
Collapse
|
4
|
Golovinskaia O, Wang CK. The hypoglycemic potential of phenolics from functional foods and their mechanisms. FOOD SCIENCE AND HUMAN WELLNESS 2023. [DOI: 10.1016/j.fshw.2022.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
5
|
Chen Y, Jia J, Zhao Q, Zhang Y, Huang B, Wang L, Tian J, Huang C, Li M, Li X. Novel Loss-of-Function Variant in HNF1a Induces β-Cell Dysfunction through Endoplasmic Reticulum Stress. Int J Mol Sci 2022; 23:ijms232113022. [PMID: 36361808 PMCID: PMC9656704 DOI: 10.3390/ijms232113022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 12/02/2022] Open
Abstract
Heterozygous variants in the hepatocyte nuclear factor 1a (HNF1a) cause MODY3 (maturity-onset diabetes of the young, type 3). In this study, we found a case of novel HNF1a p.Gln125* (HNF1a-Q125ter) variant clinically. However, the molecular mechanism linking the new HNF1a variant to impaired islet β-cell function remains unclear. Firstly, a similar HNF1a-Q125ter variant in zebrafish (hnf1a+/−) was generated by CRISPR/Cas9. We further crossed hnf1a+/− with several zebrafish reporter lines to investigate pancreatic β-cell function. Next, we introduced HNF1a-Q125ter and HNF1a shRNA plasmids into the Ins-1 cell line and elucidated the molecular mechanism. hnf1a+/− zebrafish significantly decreased the β-cell number, insulin expression, and secretion. Moreover, β cells in hnf1a+/− dilated ER lumen and increased the levels of ER stress markers. Similar ER-stress phenomena were observed in an HNF1a-Q125ter-transfected Ins-1 cell. Follow-up investigations demonstrated that HNF1a-Q125ter induced ER stress through activating the PERK/eIF2a/ATF4 signaling pathway. Our study found a novel loss-of-function HNF1a-Q125ter variant which induced β-cell dysfunction by activating ER stress via the PERK/eIF2a/ATF4 signaling pathway.
Collapse
Affiliation(s)
- Yinling Chen
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Jianxin Jia
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Qing Zhao
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
| | - Yuxian Zhang
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
- Fujian Province Key Laboratory of Diabetes Translational Medicine, Xiamen Diabetes Institute, Xiamen 361003, China
| | - Bingkun Huang
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
- Fujian Province Key Laboratory of Diabetes Translational Medicine, Xiamen Diabetes Institute, Xiamen 361003, China
| | - Likun Wang
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Juanjuan Tian
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Caoxin Huang
- Fujian Province Key Laboratory of Diabetes Translational Medicine, Xiamen Diabetes Institute, Xiamen 361003, China
| | - Mingyu Li
- Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences and School of Life Sciences, Xiamen University, Xiamen 361102, China
- Correspondence: (M.L.); (X.L.)
| | - Xuejun Li
- Department of Endocrinology and Diabetes, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361005, China
- Fujian Province Key Laboratory of Diabetes Translational Medicine, Xiamen Diabetes Institute, Xiamen 361003, China
- Correspondence: (M.L.); (X.L.)
| |
Collapse
|
6
|
Jungtrakoon Thamtarana P, Marucci A, Pannone L, Bonnefond A, Pezzilli S, Biagini T, Buranasupkajorn P, Hastings T, Mendonca C, Marselli L, Di Paola R, Abubakar Z, Mercuri L, Alberico F, Flex E, Ceròn J, Porta-de-la-Riva M, Ludovico O, Carella M, Martinelli S, Marchetti P, Mazza T, Froguel P, Trischitta V, Doria A, Prudente S. Gain of Function of Malate Dehydrogenase 2 and Familial Hyperglycemia. J Clin Endocrinol Metab 2022; 107:668-684. [PMID: 34718610 PMCID: PMC8852227 DOI: 10.1210/clinem/dgab790] [Citation(s) in RCA: 2] [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: 08/05/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Genes causing familial forms of diabetes mellitus are only partially known. OBJECTIVE We set out to identify the genetic cause of hyperglycemia in multigenerational families with an apparent autosomal dominant form of adult-onset diabetes not due to mutations in known monogenic diabetes genes. METHODS Existing whole-exome sequencing (WES) data were used to identify exonic variants segregating with diabetes in 60 families from the United States and Italy. Functional studies were carried out in vitro (transduced MIN6-K8 cells) and in vivo (Caenorhabditis elegans) to assess the diabetogenic potential of 2 variants in the malate dehydrogenase 2 (MDH2) gene linked with hyperglycemia in 2 of the families. RESULTS A very rare mutation (p.Arg52Cys) in MDH2 strongly segregated with hyperglycemia in 1 family from the United States. An infrequent MDH2 missense variant (p.Val160Met) also showed disease cosegregation in a family from Italy, although with reduced penetrance. In silico, both Arg52Cys and Val160Met were shown to affect MDH2 protein structure and function. In transfected HepG2 cells, both variants significantly increased MDH2 enzymatic activity, thereby decreasing the NAD+/NADH ratio-a change known to affect insulin signaling and secretion. Stable expression of human wild-type MDH2 in MIN6-K8 cell lines enhanced glucose- and GLP-1-stimulated insulin secretion. This effect was blunted by the Cys52 or Met160 substitutions. Nematodes carrying equivalent changes at the orthologous positions of the mdh-2 gene showed impaired glucose-stimulated insulin secretion. CONCLUSION Our findings suggest a central role of MDH2 in human glucose homeostasis and indicate that gain of function variants in this gene may be involved in the etiology of familial forms of diabetes.
Collapse
Affiliation(s)
- Prapaporn Jungtrakoon Thamtarana
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
- Cellular and Molecular Biology of Diabetes Research Group, Siriraj Center of Research Excellence for Diabetes and Obesity, Division of Molecular Medicine, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Antonella Marucci
- Research Unit of Diabetes and Endocrine Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Luca Pannone
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Amélie Bonnefond
- Inserm UMR1283, CNRS UMR8199, European Genomic Institute for Diabetes (EGID), Institut Pasteur de Lille, Lille, France
- Université de Lille, CHU de Lille, Lille, France
- Department of Metabolism, Imperial College London, London, UK
| | - Serena Pezzilli
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
- Medical Genetics, University of Chieti, Chieti, Italy
| | - Tommaso Biagini
- Unit of Bioinformatics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | | | - Timothy Hastings
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Christine Mendonca
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Rosa Di Paola
- Research Unit of Diabetes and Endocrine Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Zuroida Abubakar
- Cellular and Molecular Biology of Diabetes Research Group, Siriraj Center of Research Excellence for Diabetes and Obesity, Division of Molecular Medicine, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Luana Mercuri
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | - Federica Alberico
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | - Elisabetta Flex
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Julian Ceròn
- Modeling human diseases in C. elegans. Genes, Diseases and Therapies Program, Bellvitge Biomedical Research Institute – IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Montserrat Porta-de-la-Riva
- Modeling human diseases in C. elegans. Genes, Diseases and Therapies Program, Bellvitge Biomedical Research Institute – IDIBELL, L’Hospitalet de Llobregat, Barcelona, Spain
| | - Ornella Ludovico
- Department of Clinical Sciences, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | - Massimo Carella
- Research Unit of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Tommaso Mazza
- Unit of Bioinformatics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
| | - Philippe Froguel
- Inserm UMR1283, CNRS UMR8199, European Genomic Institute for Diabetes (EGID), Institut Pasteur de Lille, Lille, France
- Université de Lille, CHU de Lille, Lille, France
- Department of Metabolism, Imperial College London, London, UK
| | - Vincenzo Trischitta
- Research Unit of Diabetes and Endocrine Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Alessandro Doria
- Research Division, Joslin Diabetes Center, and Harvard Medical School, Boston, MA, USA
- Alessandro Doria, MD, PhD, MPH, Research Division, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215, USA.
| | - Sabrina Prudente
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo,Italy
- Correspondence: Sabrina Prudente, PhD, Fondazione IRCCS Casa Sollievo della Sofferenza, CSS-Mendel Institute, Viale Regina Margherita 261, 00198 Rome, Italy.
| |
Collapse
|
7
|
Loconte V, Singla J, Li A, Chen JH, Ekman A, McDermott G, Sali A, Le Gros M, White KL, Larabell CA. Soft X-ray tomography to map and quantify organelle interactions at the mesoscale. Structure 2022; 30:510-521.e3. [PMID: 35148829 PMCID: PMC9013509 DOI: 10.1016/j.str.2022.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/04/2021] [Accepted: 01/17/2022] [Indexed: 12/11/2022]
Abstract
Inter-organelle interactions are a vital part of normal cellular function; however, these have proven difficult to quantify due to the range of scales encountered in cell biology and the throughput limitations of traditional imaging approaches. Here, we demonstrate that soft X-ray tomography (SXT) can be used to rapidly map ultrastructural reorganization and inter-organelle interactions in intact cells. SXT takes advantage of the naturally occurring, differential X-ray absorption of the carbon-rich compounds in each organelle. Specifically, we use SXT to map the spatiotemporal evolution of insulin vesicles and their co-localization and interaction with mitochondria in pancreatic β cells during insulin secretion and in response to different stimuli. We quantify changes in the morphology, biochemical composition, and relative position of mitochondria and insulin vesicles. These findings highlight the importance of a comprehensive and unbiased mapping at the mesoscale to characterize cell reorganization that would be difficult to detect with other existing methodologies.
Collapse
Affiliation(s)
- Valentina Loconte
- iHuman Institute, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jitin Singla
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA
| | - Angdi Li
- iHuman Institute, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jian-Hua Chen
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Axel Ekman
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Gerry McDermott
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Science, Department of Pharmaceutical Chemistry, California Institute of Quantitative Bioscience, University of California San Francisco, San Francisco, CA 94158, USA
| | - Mark Le Gros
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kate L White
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA 90089, USA.
| | - Carolyn A Larabell
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| |
Collapse
|
8
|
Nan J, Lee JS, Moon JH, Lee SA, Park YJ, Lee DS, Chung SS, Park KS. SENP2 regulates mitochondrial function and insulin secretion in pancreatic β cells. Exp Mol Med 2022; 54:72-80. [PMID: 35064188 PMCID: PMC8814193 DOI: 10.1038/s12276-021-00723-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 09/22/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
AbstractIncreasing evidence has shown that small ubiquitin-like modifier (SUMO) modification plays an important role in metabolic regulation. We previously demonstrated that SUMO-specific protease 2 (SENP2) is involved in lipid metabolism in skeletal muscle and adipogenesis. In this study, we investigated the function of SENP2 in pancreatic β cells by generating a β cell-specific knockout (Senp2-βKO) mouse model. Glucose tolerance and insulin secretion were significantly impaired in the Senp2-βKO mice. In addition, glucose-stimulated insulin secretion (GSIS) was decreased in the islets of the Senp2-βKO mice without a significant change in insulin synthesis. Furthermore, islets of the Senp2-βKO mice exhibited enlarged mitochondria and lower oxygen consumption rates, accompanied by lower levels of S616 phosphorylated DRP1 (an active form of DRP1), a mitochondrial fission protein. Using a cell culture system of NIT-1, an islet β cell line, we found that increased SUMO2/3 conjugation to DRP1 due to SENP2 deficiency suppresses the phosphorylation of DRP1, which possibly induces mitochondrial dysfunction. In addition, SENP2 overexpression restored GSIS impairment induced by DRP1 knockdown and increased DRP1 phosphorylation. Furthermore, palmitate treatment decreased phosphorylated DRP1 and GSIS in β cells, which was rescued by SENP2 overexpression. These results suggest that SENP2 regulates mitochondrial function and insulin secretion at least in part by modulating the phosphorylation of DRP1 in pancreatic β cells.
Collapse
|
9
|
Hoang M, Jentz E, Janssen SM, Nasteska D, Cuozzo F, Hodson DJ, Tupling AR, Fong GH, Joseph JW. Isoform-specific Roles of Prolyl Hydroxylases in the Regulation of Pancreatic β-Cell Function. Endocrinology 2022; 163:6413706. [PMID: 34718519 PMCID: PMC8643417 DOI: 10.1210/endocr/bqab226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Indexed: 11/19/2022]
Abstract
Pancreatic β-cells can secrete insulin via 2 pathways characterized as KATP channel -dependent and -independent. The KATP channel-independent pathway is characterized by a rise in several potential metabolic signaling molecules, including the NADPH/NADP+ ratio and α-ketoglutarate (αKG). Prolyl hydroxylases (PHDs), which belong to the αKG-dependent dioxygenase superfamily, are known to regulate the stability of hypoxia-inducible factor α. In the current study, we assess the role of PHDs in vivo using the pharmacological inhibitor dimethyloxalylglycine (DMOG) and generated β-cell-specific knockout (KO) mice for all 3 isoforms of PHD (β-PHD1 KO, β-PHD2 KO, and β-PHD3 KO mice). DMOG inhibited in vivo insulin secretion in response to glucose challenge and inhibited the first phase of insulin secretion but enhanced the second phase of insulin secretion in isolated islets. None of the β-PHD KO mice showed any significant in vivo defects associated with glucose tolerance and insulin resistance except for β-PHD2 KO mice which had significantly increased plasma insulin during a glucose challenge. Islets from both β-PHD1 KO and β-PHD3 KO had elevated β-cell apoptosis and reduced β-cell mass. Isolated islets from β-PHD1 KO and β-PHD3 KO had impaired glucose-stimulated insulin secretion and glucose-stimulated increases in the ATP/ADP and NADPH/NADP+ ratio. All 3 PHD isoforms are expressed in β-cells, with PHD3 showing the most distinct expression pattern. The lack of each PHD protein did not significantly impair in vivo glucose homeostasis. However, β-PHD1 KO and β-PHD3 KO mice had defective β-cell mass and islet insulin secretion, suggesting that these mice may be predisposed to developing diabetes.
Collapse
Affiliation(s)
- Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Emelien Jentz
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Sarah M Janssen
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - A Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Guo-Hua Fong
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
- Correspondence: Jamie W. Joseph, PhD, Health Science Campus Building A, Room 4008, University of Waterloo, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5.
| |
Collapse
|
10
|
Mohan R, Jo S, Lockridge A, Ferrington DA, Murray K, Eschenlauer A, Bernal-Mizrachi E, Fujitani Y, Alejandro EU. OGT Regulates Mitochondrial Biogenesis and Function via Diabetes Susceptibility Gene Pdx1. Diabetes 2021; 70:2608-2625. [PMID: 34462257 PMCID: PMC8564412 DOI: 10.2337/db21-0468] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/19/2021] [Indexed: 12/26/2022]
Abstract
O-GlcNAc transferase (OGT), a nutrient sensor sensitive to glucose flux, is highly expressed in the pancreas. However, the role of OGT in the mitochondria of β-cells is unexplored. In this study, we identified the role of OGT in mitochondrial function in β-cells. Constitutive deletion of OGT (βOGTKO) or inducible ablation in mature β-cells (iβOGTKO) causes distinct effects on mitochondrial morphology and function. Islets from βOGTKO, but not iβOGTKO, mice display swollen mitochondria, reduced glucose-stimulated oxygen consumption rate, ATP production, and glycolysis. Alleviating endoplasmic reticulum stress by genetic deletion of Chop did not rescue the mitochondrial dysfunction in βOGTKO mice. We identified altered islet proteome between βOGTKO and iβOGTKO mice. Pancreatic and duodenal homeobox 1 (Pdx1) was reduced in in βOGTKO islets. Pdx1 overexpression increased insulin content and improved mitochondrial morphology and function in βOGTKO islets. These data underscore the essential role of OGT in regulating β-cell mitochondrial morphology and bioenergetics. In conclusion, OGT couples nutrient signal and mitochondrial function to promote normal β-cell physiology.
Collapse
Affiliation(s)
- Ramkumar Mohan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Seokwon Jo
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Amber Lockridge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Deborah A Ferrington
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN
| | - Kevin Murray
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Arthur Eschenlauer
- University of Minnesota Informatics Institute, University of Minnesota Medical School, Minneapolis, MN
| | - Ernesto Bernal-Mizrachi
- Miami VA Healthcare System, Miami, FL
- Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miami, FL
| | - Yoshio Fujitani
- Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
| | - Emilyn U Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| |
Collapse
|
11
|
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.
Collapse
Affiliation(s)
| | - Johan Perrier
- CarMeN Laboratory, INSERM U1060, INRA U1397, Lyon, France
| | | | | |
Collapse
|
12
|
Losada-Barragán M. Physiological effects of nutrients on insulin release by pancreatic beta cells. Mol Cell Biochem 2021; 476:3127-3139. [PMID: 33844157 DOI: 10.1007/s11010-021-04146-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 03/31/2021] [Indexed: 10/21/2022]
Abstract
Obesity and type 2 diabetes (T2D) are growing health problems associated with a loss of insulin sensitivity. Both conditions arise from a long-term energy imbalance, and frequently, lifestyle measures can be useful in its prevention, including physical activity and a healthy diet. Pancreatic β-cells are determinant nutrient sensors that participate in energetic homeostasis needs. However, when pancreatic β-cells are incapable of secreting enough insulin to counteract the reduced sensitivity, the pathology evolves to an insulin resistance condition. The primary nutrient that stimulates insulin secretion is glucose, but also, there are multiple dietary and hormonal factors influencing that response. Many studies of the physiology of β-cells have highlighted the importance of glucose, fructose, amino acids, and free fatty acids on insulin secretion. The present review summarizes recent research on how β-cells respond to the most abundant nutrients that influence insulin secretion. Taken together, understand the subjacent mechanisms of each nutrient on β-cells can help to unravel the effects of mixed variables and complexity in the context of β-cell pathology.
Collapse
Affiliation(s)
- Monica Losada-Barragán
- Grupo de investigación en Biología celular y funcional e ingeniería de biomoléculas, Universidad Antonio Nariño-Sede Circunvalar. Cra, 3 Este # 47A - 15, Bl 5, Bogotá, Colombia.
| |
Collapse
|
13
|
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.
Collapse
|
14
|
Abstract
Anaplerosis and the associated mitochondrial metabolite transporters generate unique cytosolic metabolic signaling molecules that can regulate insulin release from pancreatic β-cells. It has been shown that mitochondrial metabolites, transported by the citrate carrier (CIC), dicarboxylate carrier (DIC), oxoglutarate carrier (OGC), and mitochondrial pyruvate carrier (MPC) play a vital role in the regulation of glucose-stimulated insulin secretion (GSIS). Metabolomic studies on static and biphasic insulin secretion, suggests that several anaplerotic derived metabolites, including α-ketoglutarate (αKG), are strongly associated with nutrient regulated insulin secretion. Support for a role of αKG in the regulation of insulin secretion comes from studies looking at αKG dependent enzymes, including hypoxia-inducible factor-prolyl hydroxylases (PHDs) in clonal β-cells, and rodent and human islets. This review will focus on the possible link between defective anaplerotic-derived αKG, PHDs, and the development of type 2 diabetes (T2D).
Collapse
Affiliation(s)
- M. Hoang
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - J. W. Joseph
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
- CONTACT J. W. Joseph School of Pharmacy, University of Waterloo, Kitchener, ONN2G1C5, Canada
| |
Collapse
|
15
|
Chandel V, Raj S, Kumar P, Gupta S, Dhasmana A, Kesari KK, Ruokolainen J, Mehra P, Das BC, Kamal MA, Kumar D. Metabolic regulation in HPV associated head and neck squamous cell carcinoma. Life Sci 2020; 258:118236. [PMID: 32795537 DOI: 10.1016/j.lfs.2020.118236] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/25/2020] [Accepted: 08/05/2020] [Indexed: 12/13/2022]
Abstract
Cancer cells exhibit distinct energy metabolic pathways due to multiple oncogenic events. In normoxia condition, the anaerobic glycolysis (Warburg effect) is highly observed in head and neck squamous cell carcinoma (HNSCC). HNSCC is associated with smoking, chewing tobacco, consumption of alcohol or Human Papillomavirus (HPV) infection primarily HPV16. In recent years, the correlation of HPV with HNSCC has significantly expanded. Despite the recent advancement in therapeutic approaches, the rate of HPV infected HNSCC has significantly increased in the last few years, specifically, in lower middle-income countries. The oncoproteins of High-risk Human Papillomavirus (HR-HPV), E6 and E7, alter the metabolic phenotype in HNSCC, which is distinct from non-HPV associated HNSCC. These oncoproteins, modulate the cell cycle and metabolic signalling through interacting with tumor suppressor proteins, p53 and pRb. Since, metabolic alteration represents a major hallmark for tumorigenesis, HPV acts as a source of biomarker linked to cancer progression in HNSCC. The dependency of cancer cells to specific nutrients and alteration of various metabolic associated genes may provide a unique opportunity for pharmacological intervention in HPV infected HNSCC. In this review, we have discussed the molecular mechanism (s) and metabolic regulation in HNSCC depending on the HPV status. We have also discussed the possible potential therapeutic approaches for HPV associated HNSCC through targeting metabolic pathways.
Collapse
Affiliation(s)
- Vaishali Chandel
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India
| | - Sibi Raj
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India
| | - Prabhat Kumar
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India
| | - Shilpi Gupta
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India
| | - Anupam Dhasmana
- Himalayan School of Biosciences, Swami Rama Himalayan University, Swami Ram Nagar, Jolly Grant, Doiwala, Dehradun 248016, India; Department of Immunology and Microbiology, School of Medicine, University of Rio Grande Valley, McAllen, TX, USA
| | - Kavindra Kumar Kesari
- Department of Applied Physics, School of Science, Aalto University, Espoo 02150, Finland
| | - Janne Ruokolainen
- Department of Applied Physics, School of Science, Aalto University, Espoo 02150, Finland
| | - Pravesh Mehra
- Department of Oral and Maxillofacial surgery, Lady Hardinge Medical College, New Delhi, India
| | - Bhudev C Das
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India
| | - Mohammad Amjad Kamal
- King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 80216, Jeddah 21589, Saudi Arabia; Enzymoics, 7 Peterlee Place, Hebersham, NSW 2770, Australia; Novel Global Community Educational Foundation, NSW, Australia
| | - Dhruv Kumar
- Amity Institute of Molecular Medicine and Stem Cell Research (AIMMSCR), Amity University UttarPradesh, Sec 125, Noida 201303, India.
| |
Collapse
|
16
|
Maffioli E, Galli A, Nonnis S, Marku A, Negri A, Piazzoni C, Milani P, Lenardi C, Perego C, Tedeschi G. Proteomic Analysis Reveals a Mitochondrial Remodeling of βTC3 Cells in Response to Nanotopography. Front Cell Dev Biol 2020; 8:508. [PMID: 32850772 PMCID: PMC7405422 DOI: 10.3389/fcell.2020.00508] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 05/27/2020] [Indexed: 12/14/2022] Open
Abstract
Recently, using cluster-assembled zirconia substrates with tailored roughness produced by supersonic cluster beam deposition, we demonstrated that β cells can sense nanoscale features of the substrate and can translate these stimuli into a mechanotransductive pathway capable of preserveing β-cell differentiation and function in vitro in long-term cultures of human islets. Using the same proteomic approach, we now focused on the mitochondrial fraction of βTC3 cells grown on the same zirconia substrates and characterized the morphological and proteomic modifications induced by the nanostructure. The results suggest that, in βTC3 cells, mitochondria are perturbed by the nanotopography and activate a program involving metabolism modification and modulation of their interplay with other organelles. Data were confirmed in INS1E, a different β-cell model. The change induced by the nanostructure can be pro-survival and prime mitochondria for a metabolic switch to match the new cell needs.
Collapse
Affiliation(s)
- Elisa Maffioli
- Department of Veterinary Medicine, University of Milano, Milan, Italy.,Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy
| | - Alessandra Galli
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Milan, Italy
| | - Simona Nonnis
- Department of Veterinary Medicine, University of Milano, Milan, Italy.,Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy
| | - Algerta Marku
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Milan, Italy
| | - Armando Negri
- Department of Veterinary Medicine, University of Milano, Milan, Italy
| | - Claudio Piazzoni
- Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy.,Department of Physics, University of Milano, Milan, Italy
| | - Paolo Milani
- Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy.,Department of Physics, University of Milano, Milan, Italy
| | - Cristina Lenardi
- Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy.,Department of Physics, University of Milano, Milan, Italy
| | - Carla Perego
- Department of Pharmacological and Biomolecular Sciences, University of Milano, Milan, Italy
| | - Gabriella Tedeschi
- Department of Veterinary Medicine, University of Milano, Milan, Italy.,Centre for Nanostructured Materials and Interfaces, University of Milano, Milan, Italy
| |
Collapse
|
17
|
Sabadashka M, Nagalievska M, Sybirna N. Tyrosine nitration as a key event of signal transduction that regulates functional state of the cell. Cell Biol Int 2020; 45:481-497. [PMID: 31908104 DOI: 10.1002/cbin.11301] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/04/2020] [Indexed: 12/21/2022]
Abstract
This review is dedicated to the role of nitration of proteins by tyrosine residues in physiological and pathological conditions. First of all, we analyze the biochemical evidence of peroxynitrite formation and reactions that lead to its formation, types of posttranslational modifications (PTMs) induced by reactive nitrogen species, as well as three biological pathways of tyrosine nitration. Then, we describe two possible mechanisms of protein nitration that are involved in intracellular signal transduction, as well as its interconnection with phosphorylation/dephosphorylation of tyrosine. Next part of the review is dedicated to the role of proteins nitration in different pathological conditions. In this section, special attention is devoted to the role of nitration in changes of functional properties of actin-protein that undergoes PTMs both in normal and pathological conditions. Overall, this review is devoted to the main features of protein nitration by tyrosine residue and the role of this process in intracellular signal transduction in basal and pathological conditions.
Collapse
Affiliation(s)
- Mariya Sabadashka
- Department of Biochemistry, Faculty of Biology, Ivan Franko National University of Lviv, 4, Hrushevskyi St., Lviv, 79005, Ukraine
| | - Mariia Nagalievska
- Department of Biochemistry, Faculty of Biology, Ivan Franko National University of Lviv, 4, Hrushevskyi St., Lviv, 79005, Ukraine
| | - Nataliia Sybirna
- Department of Biochemistry, Faculty of Biology, Ivan Franko National University of Lviv, 4, Hrushevskyi St., Lviv, 79005, Ukraine
| |
Collapse
|
18
|
Kang GG, Francis N, Hill R, Waters D, Blanchard C, Santhakumar AB. Dietary Polyphenols and Gene Expression in Molecular Pathways Associated with Type 2 Diabetes Mellitus: A Review. Int J Mol Sci 2019; 21:ijms21010140. [PMID: 31878222 PMCID: PMC6981492 DOI: 10.3390/ijms21010140] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 02/07/2023] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder with various contributing factors including genetics, epigenetics, environment and lifestyle such as diet. The hallmarks of T2DM are insulin deficiency (also referred to as β-cell dysfunction) and insulin resistance. Robust evidence suggests that the major mechanism driving impaired β-cell function and insulin signalling is through the action of intracellular reactive oxygen species (ROS)-induced stress. Chronic high blood glucose (hyperglycaemia) and hyperlipidaemia appear to be the primary activators of these pathways. Reactive oxygen species can disrupt intracellular signalling pathways, thereby dysregulating the expression of genes associated with insulin secretion and signalling. Plant-based diets, containing phenolic compounds, have been shown to exhibit remedial benefits by ameliorating insulin secretion and insulin resistance. The literature also provides evidence that polyphenol-rich diets can modulate the expression of genes involved in insulin secretion, insulin signalling, and liver gluconeogenesis pathways. However, whether various polyphenols and phenolic compounds can target specific cellular signalling pathways involved in the pathogenesis of T2DM has not been elucidated. This review aims to evaluate the modulating effects of various polyphenols and phenolic compounds on genes involved in cellular signalling pathways (both in vitro and in vivo from human, animal and cell models) leading to the pathogenesis of T2DM.
Collapse
Affiliation(s)
- Gideon Gatluak Kang
- Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Wagga Wagga, NSW 2650, Australia; (G.G.K.); (N.F.); (D.W.); (C.B.)
- School of Biomedical Sciences, Charles Sturt University, NSW 2650, Australia;
| | - Nidhish Francis
- Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Wagga Wagga, NSW 2650, Australia; (G.G.K.); (N.F.); (D.W.); (C.B.)
- School of Animal and Veterinary Sciences, Charles Sturt University, NSW 2650, Australia
| | - Rodney Hill
- School of Biomedical Sciences, Charles Sturt University, NSW 2650, Australia;
| | - Daniel Waters
- Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Wagga Wagga, NSW 2650, Australia; (G.G.K.); (N.F.); (D.W.); (C.B.)
- School of Biomedical Sciences, Charles Sturt University, NSW 2650, Australia;
| | - Christopher Blanchard
- Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Wagga Wagga, NSW 2650, Australia; (G.G.K.); (N.F.); (D.W.); (C.B.)
- School of Biomedical Sciences, Charles Sturt University, NSW 2650, Australia;
| | - Abishek Bommannan Santhakumar
- Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Wagga Wagga, NSW 2650, Australia; (G.G.K.); (N.F.); (D.W.); (C.B.)
- School of Biomedical Sciences, Charles Sturt University, NSW 2650, Australia;
- Correspondence: ; Tel.: +61-2-6933-2678
| |
Collapse
|
19
|
Dingreville F, Panthu B, Thivolet C, Ducreux S, Gouriou Y, Pesenti S, Chauvin MA, Chikh K, Errazuriz-Cerda E, Van Coppenolle F, Rieusset J, Madec AM. Differential Effect of Glucose on ER-Mitochondria Ca 2+ Exchange Participates in Insulin Secretion and Glucotoxicity-Mediated Dysfunction of β-Cells. Diabetes 2019; 68:1778-1794. [PMID: 31175102 DOI: 10.2337/db18-1112] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 06/04/2019] [Indexed: 11/13/2022]
Abstract
Glucotoxicity-induced β-cell dysfunction in type 2 diabetes is associated with alterations of mitochondria and the endoplasmic reticulum (ER). Both organelles interact at contact sites, defined as mitochondria-associated membranes (MAMs), which were recently implicated in the regulation of glucose homeostasis. The role of MAMs in β-cells is still largely unknown, and their implication in glucotoxicity-associated β-cell dysfunction remains to be defined. Here, we report that acute glucose treatment stimulated ER-mitochondria interactions and calcium (Ca2+) exchange in INS-1E cells, whereas disruption of MAMs altered glucose-stimulated insulin secretion (GSIS). Conversely, chronic incubations with high glucose of either INS-1E cells or human pancreatic islets altered GSIS and concomitantly reduced ER Ca2+ store, increased basal mitochondrial Ca2+, and reduced ATP-stimulated ER-mitochondria Ca2+ exchanges, despite an increase of organelle interactions. Furthermore, glucotoxicity-induced perturbations of Ca2+ signaling are associated with ER stress, altered mitochondrial respiration, and mitochondria fragmentation, and these organelle stresses may participate in increased organelle tethering as a protective mechanism. Last, sustained induction of ER-mitochondria interactions using a linker reduced organelle Ca2+ exchange, induced mitochondrial fission, and altered GSIS. Therefore, dynamic organelle coupling participates in GSIS in β-cells, and over time, disruption of organelle Ca2+ exchange might be a novel mechanism contributing to glucotoxicity-induced β-cell dysfunction.
Collapse
Affiliation(s)
- Florian Dingreville
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Baptiste Panthu
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Charles Thivolet
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
- Department of Endocrinology and Diabetes, Hospices Civils de Lyon, Hopital Lyon Sud, Pierre-Bénite, France
| | - Sylvie Ducreux
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Yves Gouriou
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Sandra Pesenti
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Marie-Agnès Chauvin
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Karim Chikh
- Department of Endocrinology and Diabetes, Hospices Civils de Lyon, Hopital Lyon Sud, Pierre-Bénite, France
| | | | - Fabien Van Coppenolle
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Jennifer Rieusset
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| | - Anne-Marie Madec
- CarMeN Laboratory, INSERM, INRA, INSA, Université Claude Bernard Lyon 1, Oullins, France
| |
Collapse
|
20
|
Zbinden A, Marzi J, Schlünder K, Probst C, Urbanczyk M, Black S, Brauchle EM, Layland SL, Kraushaar U, Duffy G, Schenke-Layland K, Loskill P. Non-invasive marker-independent high content analysis of a microphysiological human pancreas-on-a-chip model. Matrix Biol 2019; 85-86:205-220. [PMID: 31238092 DOI: 10.1016/j.matbio.2019.06.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 12/15/2022]
Abstract
The increasing prevalence of diabetes, its heterogeneity, and the limited number of treatment options drive the need for physiologically relevant assay platforms with human genetic background that have the potential to improve mechanistic understanding and e\xpedite diabetes-related research and treatment. In this study, we developed an endocrine pancreas-on-a-chip model based on a tailored microfluidic platform, which enables self-guided trapping of single human pseudo-islets. Continuous, low-shear perfusion provides a physiologically relevant microenvironment especially important for modeling and monitoring of the endocrine function as well as sufficient supply with nutrients and oxygen. Human pseudo-islets, generated from the conditionally immortalized EndoC-βH3 cell line, were successfully injected by hydrostatic pressure-driven flow without altered viability. To track insulin secretion kinetics in response to glucose stimulation in a time-resolved manner, dynamic sampling of the supernatant as well as non-invasive real-time monitoring using Raman microspectroscopy was established on-chip. Dynamic sampling indicated a biphasic glucose-stimulated insulin response. Raman microspectroscopy allowed to trace glucose responsiveness in situ and to visualize different molecular structures such as lipids, mitochondria and nuclei. In-depth spectral analyses demonstrated a glucose stimulation-dependent, increased mitochondrial activity, and a switch in lipid composition of insulin secreting vesicles, supporting the high performance of our pancreas-on-a-chip model.
Collapse
Affiliation(s)
- Aline Zbinden
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany
| | - Julia Marzi
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany; The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Katharina Schlünder
- Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Christopher Probst
- Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany
| | - Max Urbanczyk
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany
| | - Scott Black
- The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Eva M Brauchle
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany; The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Shannon L Layland
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany
| | - Udo Kraushaar
- The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany
| | - Garry Duffy
- Discipline of Anatomy and the Regenerative Medicine Institute, School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Ireland; Science Foundation Ireland (SFI), Centre for Research in Advanced Materials for Biomedical Engineering (AMBER), Trinity College Dublin, National University of Ireland Galway, Galway, Ireland
| | - Katja Schenke-Layland
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany; The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany; Dept. of Medicine/Cardiology, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
| | - Peter Loskill
- Dept. of Women's Health, Research Institute of Women's Health, Eberhard Karls University Tübingen, Germany; Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), Stuttgart, Germany.
| |
Collapse
|
21
|
Fex M, Nicholas LM, Vishnu N, Medina A, Sharoyko VV, Nicholls DG, Spégel P, Mulder H. The pathogenetic role of β-cell mitochondria in type 2 diabetes. J Endocrinol 2018; 236:R145-R159. [PMID: 29431147 DOI: 10.1530/joe-17-0367] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 01/15/2018] [Indexed: 12/17/2022]
Abstract
Mitochondrial metabolism is a major determinant of insulin secretion from pancreatic β-cells. Type 2 diabetes evolves when β-cells fail to release appropriate amounts of insulin in response to glucose. This results in hyperglycemia and metabolic dysregulation. Evidence has recently been mounting that mitochondrial dysfunction plays an important role in these processes. Monogenic dysfunction of mitochondria is a rare condition but causes a type 2 diabetes-like syndrome owing to β-cell failure. Here, we describe novel advances in research on mitochondrial dysfunction in the β-cell in type 2 diabetes, with a focus on human studies. Relevant studies in animal and cell models of the disease are described. Transcriptional and translational regulation in mitochondria are particularly emphasized. The role of metabolic enzymes and pathways and their impact on β-cell function in type 2 diabetes pathophysiology are discussed. The role of genetic variation in mitochondrial function leading to type 2 diabetes is highlighted. We argue that alterations in mitochondria may be a culprit in the pathogenetic processes culminating in type 2 diabetes.
Collapse
Affiliation(s)
- Malin Fex
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Lisa M Nicholas
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Neelanjan Vishnu
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Anya Medina
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Vladimir V Sharoyko
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - David G Nicholls
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| | - Peter Spégel
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
- Department of ChemistryCenter for Analysis and Synthesis, Lund University, Sweden
| | - Hindrik Mulder
- Department of Clinical Sciences in MalmöUnit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden
| |
Collapse
|
22
|
Andersson LE, Shcherbina L, Al-Majdoub M, Vishnu N, Arroyo CB, Aste Carrara J, Wollheim CB, Fex M, Mulder H, Wierup N, Spégel P. Glutamine-Elicited Secretion of Glucagon-Like Peptide 1 Is Governed by an Activated Glutamate Dehydrogenase. Diabetes 2018; 67:372-384. [PMID: 29229616 DOI: 10.2337/db16-1441] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 12/07/2017] [Indexed: 11/13/2022]
Abstract
Glucagon-like peptide 1 (GLP-1), secreted from intestinal L cells, glucose dependently stimulates insulin secretion from β-cells. This glucose dependence prevents hypoglycemia, rendering GLP-1 analogs a useful and safe treatment modality in type 2 diabetes. Although the amino acid glutamine is a potent elicitor of GLP-1 secretion, the responsible mechanism remains unclear. We investigated how GLP-1 secretion is metabolically coupled in L cells (GLUTag) and in vivo in mice using the insulin-secreting cell line INS-1 832/13 as reference. A membrane-permeable glutamate analog (dimethylglutamate [DMG]), acting downstream of electrogenic transporters, elicited similar alterations in metabolism as glutamine in both cell lines. Both DMG and glutamine alone elicited GLP-1 secretion in GLUTag cells and in vivo, whereas activation of glutamate dehydrogenase (GDH) was required to stimulate insulin secretion from INS-1 832/13 cells. Pharmacological inhibition in vivo of GDH blocked secretion of GLP-1 in response to DMG. In conclusion, our results suggest that nonelectrogenic nutrient uptake and metabolism play an important role in L cell stimulus-secretion coupling. Metabolism of glutamine and related analogs by GDH in the L cell may explain why GLP-1 secretion, but not that of insulin, is activated by these secretagogues in vivo.
Collapse
Affiliation(s)
- Lotta E Andersson
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Liliya Shcherbina
- Neuroendocrine Cell Biology, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Mahmoud Al-Majdoub
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Neelanjan Vishnu
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | | | - Jonathan Aste Carrara
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Sweden
| | - Claes B Wollheim
- Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
- Department of Cell Physiology and Metabolism, University Medical Centre, Geneva, Switzerland
| | - Malin Fex
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Hindrik Mulder
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Nils Wierup
- Neuroendocrine Cell Biology, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
| | - Peter Spégel
- Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, Skåne University Hospital, Malmö, Sweden
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Sweden
| |
Collapse
|
23
|
Kang OH, Shon MY, Kong R, Seo YS, Zhou T, Kim DY, Kim YS, Kwon DY. Anti-diabetic effect of black ginseng extract by augmentation of AMPK protein activity and upregulation of GLUT2 and GLUT4 expression in db/db mice. Altern Ther Health Med 2017; 17:341. [PMID: 28662663 PMCID: PMC5492680 DOI: 10.1186/s12906-017-1839-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 06/15/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND Black ginseng (Panax ginseng C. A. Meyer), three to nine times-steamed and dried ginseng, has biological and pharmacological activities. In this study, the anti-diabetic effects of the black ginseng ethanol extract (GBG05-FF) in typical type 2 diabetic model db/db mice were investigated. METHODS The effect of GBG05-FF in Type 2 diabetic mice was investigated by their blood analysis, biological mechanism analysis, and histological analysis. RESULTS The mice group treated with GBG05-FF showed decreased fasting blood glucose and glucose tolerance compared to that of the nontreated GBG05-FF group. In the blood analysis, GBG05-FF decreased main plasma parameter such as HbA1c, triglyceride, and total-cholesterol levels related to diabetes and improved the expression of genes and protein related to glucose homeostasis and glucose uptake in the liver and muscle. The histological analysis result shows that GBG05-FF decreased lipid accumulation in the liver and damage in the muscle. Moreover, GBG05-FF increased the phosphorylation of the AMPK in the liver and upregulated the expression of GLUT2 in liver and GLUT4 in muscle. Therefore, the mechanisms of GBG05-FF may be related to suppressing gluconeogenesis by activating AMPK in the liver and affecting glucose uptake in surrounding tissues via the upregulation of GLUT2 and GLUT4 expression. CONCLUSION These findings provided a new insight into the anti-diabetic clinical applications of GBG05-FF and it might play an important role in the development of promising functional foods and drugs from the viewpoint of the chemical composition and biological activities.
Collapse
|
24
|
Wollam J, Mahata S, Riopel M, Hernandez-Carretero A, Biswas A, Bandyopadhyay GK, Chi NW, Eiden LE, Mahapatra NR, Corti A, Webster NJG, Mahata SK. Chromogranin A regulates vesicle storage and mitochondrial dynamics to influence insulin secretion. Cell Tissue Res 2017; 368:487-501. [PMID: 28220294 PMCID: PMC10843982 DOI: 10.1007/s00441-017-2580-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 01/16/2017] [Indexed: 01/01/2023]
Abstract
Chromogranin A (CgA) is a prohormone and a granulogenic factor that regulates secretory pathways in neuroendocrine tissues. In β-cells of the endocrine pancreas, CgA is a major cargo in insulin secretory vesicles. The impact of CgA deficiency on the formation and exocytosis of insulin vesicles is yet to be investigated. In addition, no literature exists on the impact of CgA on mitochondrial function in β-cells. Using three different antibodies, we demonstrate that CgA is processed to vasostatin- and catestatin-containing fragments in pancreatic islet cells. CgA deficiency in Chga-KO islets leads to compensatory overexpression of chromogranin B, secretogranin II, SNARE proteins and insulin genes, as well as increased insulin protein content. Ultrastructural studies of pancreatic islets revealed that Chga-KO β-cells contain fewer immature secretory granules than wild-type (WT) control but increased numbers of mature secretory granules and plasma membrane-docked vesicles. Compared to WT control, CgA-deficient β-cells exhibited increases in mitochondrial volume, numerical densities and fusion, as well as increased expression of nuclear encoded genes (Ndufa9, Ndufs8, Cyc1 and Atp5o). These changes in secretory vesicles and the mitochondria likely contribute to the increased glucose-stimulated insulin secretion observed in Chga-KO mice. We conclude that CgA is an important regulator for coordination of mitochondrial dynamics, secretory vesicular quanta and GSIS for optimal secretory functioning of β-cells, suggesting a strong, CgA-dependent positive link between mitochondrial fusion and GSIS.
Collapse
Affiliation(s)
- Joshua Wollam
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Sumana Mahata
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Matthew Riopel
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Angshuman Biswas
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Nai-Wen Chi
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| | - Lee E Eiden
- Section on Molecular Neuroscience, NIMH-IRP, Bethesda, MD, USA
| | - Nitish R Mahapatra
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Angelo Corti
- IRCCS San Raffaele Scientific Institute, San Raffaele Vita-Salute University, Milan, Italy
| | - Nicholas J G Webster
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, San Diego, CA, USA
| | - Sushil K Mahata
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
- VA San Diego Healthcare System, San Diego, CA, USA.
- Metabolic Physiology & Ultrastructural Biology Laboratory, Department of Medicine, University of California, San Diego (0732), 9500 Gilman Drive, La Jolla, CA, 92093-0732, USA.
| |
Collapse
|
25
|
Mulder H. Transcribing β-cell mitochondria in health and disease. Mol Metab 2017; 6:1040-1051. [PMID: 28951827 PMCID: PMC5605719 DOI: 10.1016/j.molmet.2017.05.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 05/13/2017] [Accepted: 05/22/2017] [Indexed: 12/17/2022] Open
Abstract
Background The recent genome-wide association studies (GWAS) of Type 2 Diabetes (T2D) have identified the pancreatic β-cell as the culprit in the pathogenesis of the disease. Mitochondrial metabolism plays a crucial role in the processes controlling release of insulin and β-cell mass. This notion implies that mechanisms controlling mitochondrial function have the potential to play a decisive pathogenetic role in T2D. Scope of the review This article reviews studies demonstrating that there is indeed mitochondrial dysfunction in islets in T2D, and that GWAS have identified a variant in the gene encoding transcription factor B1 mitochondrial (TFB1M), predisposing to T2D due to mitochondrial dysfunction and impaired insulin secretion. Mechanistic studies of the nature of this pathogenetic link, as well as of other mitochondrial transcription factors, are described. Major conclusions Based on this, it is argued that transcription and translation in mitochondria are critical processes determining mitochondrial function in β-cells in health and disease.
Collapse
Key Words
- AMPK, AMP-dependent protein kinase
- ATGL, adipocyte triglyceride lipase
- COX, Cytochrome c oxidase
- CYTB, Cytochrome b
- ERR-α, Estrogen-related receptor-α
- Expression quantitative trait locus (eQTL)
- GDH, Glutamate dehydrogenase
- GSIS, Glucose-stimulated insulin secretion
- GWAS, Genome-wide association study
- Genome-wide association study (GWAS)
- HSL, Hormone-sensitive lipase
- ICDc, Cytosolic isocitrate dehydrogenase
- Insulin secretion
- Islets
- KATP, ATP-dependent K+-channel
- MTERF, Mitochondrial transcription termination factor
- Mitochondria
- ND, NADH dehydrogenase
- NRF, Nuclear respiratory factor
- NSUN4, NOP2/Sun RNA methyltransferase family member 4
- OXPHOS, Oxidative phosphorylation
- PC, Pyruvate carboxylase
- PDH, pyruvate dehydrogenase
- PGC, Peroxisome proliferator-activated receptor-γ co-activator
- POLRMT, Mitochondrial RNA polymerase
- POLγ, DNA polymerase-γ
- PPARγ, Peroxisome proliferator-activated receptor-γ
- PRC, PGC1-related coactivator
- SENP1, Sentrin/SUMO-specific protease-1
- SNP, Single Nucleotide Polymorphism
- SUR1, Sulphonylurea receptor-1
- T2D, Type 2 Diabetes
- TCA, Tricarboxylic acid
- TEFM, Mitochondrial transcription elongation factor
- TFAM, Transcription factor A mitochondrial
- TFB1M, Transcription factor B1 mitochondrial
- TFB2M, Transcription factor B2 mitochondrial
- eQTL, Expression quantitative trait locus
- β-Cell
Collapse
Affiliation(s)
- Hindrik Mulder
- Unit of Molecular Metabolism, Lund University Diabetes Centre, Malmö, Sweden
| |
Collapse
|
26
|
Cappelli APG, Zoppi CC, Silveira LR, Batista TM, Paula FM, da Silva PMR, Rafacho A, Barbosa-Sampaio HC, Boschero AC, Carneiro EM. Reduced glucose-induced insulin secretion in low-protein-fed rats is associated with altered pancreatic islets redox status. J Cell Physiol 2017; 233:486-496. [PMID: 28370189 DOI: 10.1002/jcp.25908] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/13/2017] [Indexed: 01/01/2023]
Abstract
In the present study, we investigated the relationship between early life protein malnutrition-induced redox imbalance, and reduced glucose-stimulated insulin secretion. After weaning, male Wistar rats were submitted to a normal-protein-diet (17%-protein, NP) or to a low-protein-diet (6%-protein, LP) for 60 days. Pancreatic islets were isolated and hydrogen peroxide (H2 O2 ), oxidized (GSSG) and reduced (GSH) glutathione content, CuZn-superoxide dismutase (SOD1), glutathione peroxidase (GPx1) and catalase (CAT) gene expression, as well as enzymatic antioxidant activities were quantified. Islets that were pre-incubated with H2 O2 and/or N-acetylcysteine, were subsequently incubated with glucose for insulin secretion measurement. Protein malnutrition increased CAT mRNA content by 100%. LP group SOD1 and CAT activities were 50% increased and reduced, respectively. H2 O2 production was more than 50% increased whereas GSH/GSSG ratio was near 60% lower in LP group. Insulin secretion was, in most conditions, approximately 50% lower in LP rat islets. When islets were pre-incubated with H2 O2 (100 μM), and incubated with glucose (33 mM), LP rats showed significant decrease of insulin secretion. This effect was attenuated when LP islets were exposed to N-acetylcysteine.
Collapse
Affiliation(s)
- Ana Paula G Cappelli
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão (UFMA), São Luís, Maranhão, Brazil.,Department of Physiology and Biophysiology, Institute of Biomedical Sciences, University of Sao Paulo (USP), São Paulo, Brazil
| | - Claudio C Zoppi
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Leonardo R Silveira
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Thiago M Batista
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Flávia M Paula
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | | | - Alex Rafacho
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.,Department of Physiologic Sciences, Center of Biologic Sciences, Federal University of Santa Catarina (UFSC), Florianopolis, Santa Catarina, Brazil
| | - Helena C Barbosa-Sampaio
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Antonio C Boschero
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Everardo M Carneiro
- Department of Structural and Functional Biology, Cellular Biology and Physiology and Biophysics, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| |
Collapse
|
27
|
Eanes WF. New views on the selection acting on genetic polymorphism in central metabolic genes. Ann N Y Acad Sci 2016; 1389:108-123. [PMID: 27859384 DOI: 10.1111/nyas.13285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/20/2016] [Accepted: 09/29/2016] [Indexed: 12/14/2022]
Abstract
Studies of the polymorphism of central metabolic genes as a source of fitness variation in natural populations date back to the discovery of allozymes in the 1960s. The unique features of these genes and their enzymes and our knowledge base greatly facilitates the systems-level study of this group. The expectation that pathway flux control is central to understanding the molecular evolution of genes is discussed, as well as studies that attempt to place gene-specific molecular evolution and polymorphism into a context of pathway and network architecture. There is an increasingly complex picture of the metabolic genes assuming additional roles beyond their textbook anabolic and catabolic reactions. In particular, this review emphasizes the potential role of these genes as part of the energy-sensing machinery. It is underscored that the concentrations of key cellular metabolites are the reflections of cellular energy status and nutritional input. These metabolites are the top-down signaling messengers that set signaling through signaling pathways that are involved in energy economy. I propose that the polymorphisms in central metabolic genes shift metabolite concentrations and in that fashion act as genetic modifiers of the energy-state coupling to the transcriptional networks that affect physiological trade-offs with significant fitness consequences.
Collapse
Affiliation(s)
- Walter F Eanes
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York
| |
Collapse
|
28
|
Gerencser AA, Mookerjee SA, Jastroch M, Brand MD. Positive Feedback Amplifies the Response of Mitochondrial Membrane Potential to Glucose Concentration in Clonal Pancreatic Beta Cells. Biochim Biophys Acta Mol Basis Dis 2016; 1863:1054-1065. [PMID: 27771512 DOI: 10.1016/j.bbadis.2016.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 10/16/2016] [Accepted: 10/18/2016] [Indexed: 02/07/2023]
Abstract
Analysis of the cellular mechanisms of metabolic disorders, including type 2 diabetes mellitus, is complicated by the large number of reactions and interactions in metabolic networks. Metabolic control analysis with appropriate modularization is a powerful method for simplifying and analyzing these networks. To analyze control of cellular energy metabolism in adherent cell cultures of the INS-1 832/13 pancreatic β-cell model we adapted our microscopy assay of absolute mitochondrial membrane potential (ΔψM) to a fluorescence microplate reader format, and applied it in conjunction with cell respirometry. In these cells the sensitive response of ΔψM to extracellular glucose concentration drives glucose-stimulated insulin secretion. Using metabolic control analysis we identified the control properties that generate this sensitive response. Force-flux relationships between ΔψM and respiration were used to calculate kinetic responses to ΔψM of processes both upstream (glucose oxidation) and downstream (proton leak and ATP turnover) of ΔψM. The analysis revealed that glucose-evoked ΔψM hyperpolarization is amplified by increased glucose oxidation activity caused by factors downstream of ΔψM. At high glucose, the hyperpolarized ΔψM is stabilized almost completely by the action of glucose oxidation, whereas proton leak also contributes to the homeostatic control of ΔψM at low glucose. These findings suggest a strong positive feedback loop in the regulation of β-cell energetics, and a possible regulatory role of proton leak in the fasting state. Analysis of islet bioenergetics from published cases of type 2 diabetes suggests that disruption of this feedback can explain the damaged bioenergetic response of β-cells to glucose. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.
Collapse
Affiliation(s)
- Akos A Gerencser
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States; Image Analyst Software, 43 Nova Lane, Novato, CA 94945, United States.
| | - Shona A Mookerjee
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States; Touro University California College of Pharmacy, 1310 Club Drive, Vallejo, CA 94592, United States
| | - Martin Jastroch
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States
| | - Martin D Brand
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA 94945, United States
| |
Collapse
|
29
|
Yi L, Bandak B, Wang X, Bertram R, Roper MG. Dual Detection System for Simultaneous Measurement of Intracellular Fluorescent Markers and Cellular Secretion. Anal Chem 2016; 88:10368-10373. [PMID: 27712062 DOI: 10.1021/acs.analchem.6b02404] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glucose-stimulated insulin secretion from pancreatic β-cells within islets of Langerhans plays a critical role in maintaining glucose homeostasis. Although this process is essential for maintaining euglycemia, the underlying intracellular mechanisms that control it are still unclear. To allow simultaneous correlation between intracellular signal transduction events and extracellular secretion, an analytical system was developed that integrates fluorescence imaging of intracellular probes with high-speed automated insulin immunoassays. As a demonstration of the system, intracellular [Ca2+] ([Ca2+]i) was measured by imaging Fura-2 fluorescence simultaneously with insulin secretion from islets exposed to elevated glucose levels. Both [Ca2+]i and insulin were oscillatory during application of 10 mM glucose with temporal and quantitative profiles similar to what has been observed elsewhere. In previous work, sinusoidal glucose levels have been used to test the entrainment of islets while monitoring either [Ca2+]i or insulin levels; using this newly developed system, we show unambiguously that oscillations of both [Ca2+]i and insulin release are entrained to oscillatory glucose levels and that the temporal correlation of these are maintained throughout the experiment. It is expected that the developed analytical system can be expanded to investigate a number of other intracellular messengers in islets or other stimulus-secretion pathways in different cells.
Collapse
Affiliation(s)
- Lian Yi
- Department of Chemistry and Biochemistry, Florida State University , 95 Chieftain Way, Dittmer Building, Tallahassee, Florida 32306, United States
| | - Basel Bandak
- Department of Chemistry and Biochemistry, Florida State University , 95 Chieftain Way, Dittmer Building, Tallahassee, Florida 32306, United States
| | - Xue Wang
- Department of Chemistry and Biochemistry, Florida State University , 95 Chieftain Way, Dittmer Building, Tallahassee, Florida 32306, United States
| | - Richard Bertram
- Department of Mathematics and Program in Neuroscience, Florida State University , Tallahassee, Florida 32306, United States.,Program in Molecular Biophysics, Florida State University , Tallahassee, Florida 32306, United States
| | - Michael G Roper
- Department of Chemistry and Biochemistry, Florida State University , 95 Chieftain Way, Dittmer Building, Tallahassee, Florida 32306, United States.,Program in Molecular Biophysics, Florida State University , Tallahassee, Florida 32306, United States
| |
Collapse
|
30
|
Protein malnutrition potentiates the amplifying pathway of insulin secretion in adult obese mice. Sci Rep 2016; 6:33464. [PMID: 27633083 PMCID: PMC5025848 DOI: 10.1038/srep33464] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 08/30/2016] [Indexed: 12/28/2022] Open
Abstract
Pancreatic beta cell (β) dysfunction is an outcome of malnutrition. We assessed the role of the amplifying pathway (AMP PATH) in β cells in malnourished obese mice. C57Bl-6 mice were fed a control (C) or a low-protein diet (R). The groups were then fed a high-fat diet (CH and RH). AMP PATH contribution to insulin secretion was assessed upon incubating islets with diazoxide and KCl. CH and RH displayed increased glucose intolerance, insulin resistance and glucose-stimulated insulin secretion. Only RH showed a higher contribution of the AMP PATH. The mitochondrial membrane potential of RH was decreased, and ATP flux was unaltered. In RH islets, glutamate dehydrogenase (GDH) protein content and activity increased, and the AMP PATH contribution was reestablished when GDH was blunted. Thus, protein malnutrition induces mitochondrial dysfunction in β cells, leading to an increased contribution of the AMP PATH to insulin secretion through the enhancement of GDH content and activity.
Collapse
|
31
|
Kusminski CM, Chen S, Ye R, Sun K, Wang QA, Spurgin SB, Sanders PE, Brozinick JT, Geldenhuys WJ, Li WH, Unger RH, Scherer PE. MitoNEET-Parkin Effects in Pancreatic α- and β-Cells, Cellular Survival, and Intrainsular Cross Talk. Diabetes 2016; 65:1534-55. [PMID: 26895793 PMCID: PMC5310214 DOI: 10.2337/db15-1323] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/06/2016] [Indexed: 12/16/2022]
Abstract
Mitochondrial metabolism plays an integral role in glucose-stimulated insulin secretion (GSIS) in β-cells. In addition, the diabetogenic role of glucagon released from α-cells plays a major role in the etiology of both type 1 and type 2 diabetes because unopposed hyperglucagonemia is a pertinent contributor to diabetic hyperglycemia. Titrating expression levels of the mitochondrial protein mitoNEET is a powerful approach to fine-tune mitochondrial capacity of cells. Mechanistically, β-cell-specific mitoNEET induction causes hyperglycemia and glucose intolerance due to activation of a Parkin-dependent mitophagic pathway, leading to the formation of vacuoles and uniquely structured mitophagosomes. Induction of mitoNEET in α-cells leads to fasting-induced hypoglycemia and hypersecretion of insulin during GSIS. MitoNEET-challenged α-cells exert potent antiapoptotic effects on β-cells and prevent cellular dysfunction associated with mitoNEET overexpression in β-cells. These observations identify that reduced mitochondrial function in α-cells exerts potently protective effects on β-cells, preserving β-cell viability and mass.
Collapse
Affiliation(s)
- Christine M Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Shiuhwei Chen
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Risheng Ye
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Qiong A Wang
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Stephen B Spurgin
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Phillip E Sanders
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, IN
| | - Joseph T Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Co., Indianapolis, IN
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV
| | - Wen-Hong Li
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Roger H Unger
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, TX Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, TX
| |
Collapse
|
32
|
Reinhardt F, Schultz J, Waterstradt R, Baltrusch S. Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells. Biochem Biophys Res Commun 2016; 474:646-651. [PMID: 27154223 DOI: 10.1016/j.bbrc.2016.04.142] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 04/28/2016] [Indexed: 10/21/2022]
Abstract
Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 was down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion.
Collapse
Affiliation(s)
- Florian Reinhardt
- Institute of Medical Biochemistry and Molecular Biology, University of Rostock, D-18057 Rostock, Germany
| | - Julia Schultz
- Institute of Medical Biochemistry and Molecular Biology, University of Rostock, D-18057 Rostock, Germany
| | - Rica Waterstradt
- Institute of Medical Biochemistry and Molecular Biology, University of Rostock, D-18057 Rostock, Germany
| | - Simone Baltrusch
- Institute of Medical Biochemistry and Molecular Biology, University of Rostock, D-18057 Rostock, Germany.
| |
Collapse
|
33
|
Hals IK, Bruerberg SG, Ma Z, Scholz H, Björklund A, Grill V. Mitochondrial Respiration in Insulin-Producing β-Cells: General Characteristics and Adaptive Effects of Hypoxia. PLoS One 2015; 10:e0138558. [PMID: 26401848 PMCID: PMC4581632 DOI: 10.1371/journal.pone.0138558] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 09/01/2015] [Indexed: 01/04/2023] Open
Abstract
Objective To provide novel insights on mitochondrial respiration in β-cells and the adaptive effects of hypoxia. Methods and Design Insulin-producing INS-1 832/13 cells were exposed to 18 hours of hypoxia followed by 20–22 hours re-oxygenation. Mitochondrial respiration was measured by high-resolution respirometry in both intact and permeabilized cells, in the latter after establishing three functional substrate-uncoupler-inhibitor titration (SUIT) protocols. Concomitant measurements included proteins of mitochondrial complexes (Western blotting), ATP and insulin secretion. Results Intact cells exhibited a high degree of intrinsic uncoupling, comprising about 50% of oxygen consumption in the basal respiratory state. Hypoxia followed by re-oxygenation increased maximal overall respiration. Exploratory experiments in peremabilized cells could not show induction of respiration by malate or pyruvate as reducing substrates, thus glutamate and succinate were used as mitochondrial substrates in SUIT protocols. Permeabilized cells displayed a high capacity for oxidative phosphorylation for both complex I- and II-linked substrates in relation to maximum capacity of electron transfer. Previous hypoxia decreased phosphorylation control of complex I-linked respiration, but not in complex II-linked respiration. Coupling control ratios showed increased coupling efficiency for both complex I- and II-linked substrates in hypoxia-exposed cells. Respiratory rates overall were increased. Also previous hypoxia increased proteins of mitochondrial complexes I and II (Western blotting) in INS-1 cells as well as in rat and human islets. Mitochondrial effects were accompanied by unchanged levels of ATP, increased basal and preserved glucose-induced insulin secretion. Conclusions Exposure of INS-1 832/13 cells to hypoxia, followed by a re-oxygenation period increases substrate-stimulated respiratory capacity and coupling efficiency. Such effects are accompanied by up-regulation of mitochondrial complexes also in pancreatic islets, highlighting adaptive capacities of possible importance in an islet transplantation setting. Results also indicate idiosyncrasies of β-cells that do not respire in response to a standard inclusion of malate in SUIT protocols.
Collapse
Affiliation(s)
- Ingrid K. Hals
- Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- * E-mail:
| | - Simon Gustafson Bruerberg
- Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Zuheng Ma
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Hanne Scholz
- Department of Transplantation Medicine and Institute for Surgical Research, Oslo University Hospital, Oslo, Norway
| | - Anneli Björklund
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Valdemar Grill
- Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Endocrinology, St Olav University Hospital, Trondheim, Norway
| |
Collapse
|
34
|
Wu J, Yan LJ. Streptozotocin-induced type 1 diabetes in rodents as a model for studying mitochondrial mechanisms of diabetic β cell glucotoxicity. Diabetes Metab Syndr Obes 2015; 8:181-8. [PMID: 25897251 PMCID: PMC4396517 DOI: 10.2147/dmso.s82272] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Chronic hyperglycemia and the corresponding glucotoxicity are the main pathogenic mechanisms of diabetes and its complications. Streptozotocin (STZ)-induced diabetic animal models are useful platforms for the understanding of β cell glucotoxicity in diabetes. As diabetes induced by a single STZ injection is often referred to as type 1 diabetes that is caused by STZ's partial destruction of pancreas, one question often being asked is whether the STZ type 1 diabetes animal model is a good model for studying the mitochondrial mechanisms of β cell glucotoxicity. In this mini review, we provide evidence garnered from the literature that the STZ type 1 diabetes is indeed a suitable model for studying mitochondrial mechanisms of diabetic β cell glucotoxicity. Evidence presented includes: 1) continued β cell derangement is due to chronic hyperglycemia after STZ is completely eliminated out of the body; 2) STZ diabetes can be reversed by insulin treatment, which indicates that β cell responds to treatment and shows ability to regenerate; and 3) STZ diabetes can be ameliorated or alleviated by administration of phytochemicals. In addition, mechanisms of STZ action and fundamental gaps in understanding mitochondrial mechanisms of β cell dysfunction are also discussed.
Collapse
Affiliation(s)
- Jinzi Wu
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| |
Collapse
|
35
|
Luo X, Li R, Yan LJ. Roles of Pyruvate, NADH, and Mitochondrial Complex I in Redox Balance and Imbalance in β Cell Function and Dysfunction. J Diabetes Res 2015; 2015:512618. [PMID: 26568959 PMCID: PMC4629043 DOI: 10.1155/2015/512618] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/26/2014] [Accepted: 11/27/2014] [Indexed: 12/25/2022] Open
Abstract
Pancreatic β cells not only use glucose as an energy source, but also sense blood glucose levels for insulin secretion. While pyruvate and NADH metabolic pathways are known to be involved in regulating insulin secretion in response to glucose stimulation, the roles of many other components along the metabolic pathways remain poorly understood. Such is the case for mitochondrial complex I (NADH/ubiquinone oxidoreductase). It is known that normal complex I function is absolutely required for episodic insulin secretion after a meal, but the role of complex I in β cells in the diabetic pancreas remains to be investigated. In this paper, we review the roles of pyruvate, NADH, and complex I in insulin secretion and hypothesize that complex I plays a crucial role in the pathogenesis of β cell dysfunction in the diabetic pancreas. This hypothesis is based on the establishment that chronic hyperglycemia overloads complex I with NADH leading to enhanced complex I production of reactive oxygen species. As nearly all metabolic pathways are impaired in diabetes, understanding how complex I in the β cells copes with elevated levels of NADH in the diabetic pancreas may provide potential therapeutic strategies for diabetes.
Collapse
Affiliation(s)
- Xiaoting Luo
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
- Department of Biochemistry and Molecular Biology, Gannan Medical University, Ganzhou, Jiangxi 341000, China
| | - Rongrong Li
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
| | - Liang-Jun Yan
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107, USA
- *Liang-Jun Yan:
| |
Collapse
|
36
|
Szkudelski T, Szkudelska K. Regulatory role of adenosine in insulin secretion from pancreatic β-cells--action via adenosine A₁ receptor and beyond. J Physiol Biochem 2014; 71:133-40. [PMID: 25432862 DOI: 10.1007/s13105-014-0371-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 11/17/2014] [Indexed: 01/04/2023]
Abstract
Under physiological conditions, insulin secretion from pancreatic β-cells is tightly regulated by different factors, including nutrients, nervous system, and other hormones. Pancreatic β-cells are also influenced by paracrine and autocrine interactions. The results of rodent studies indicate that adenosine is present within pancreatic islets and is implicated in the regulation of insulin secretion; however, effects depend on adenosine and glucose concentrations. Moreover, species differences in adenosine action were found. In rat islets, low adenosine was demonstrated to decrease glucose-induced insulin secretion and this effect is mediated via adenosine A1 receptor. In the presence of high adenosine concentrations, other mechanisms are activated and glucose-induced insulin secretion is increased. It is also well established that suppression of adenosine action increases insulin-secretory response of β-cells to glucose. In mouse islets, low adenosine concentrations do not significantly affect insulin secretion. However, in the presence of higher adenosine concentrations, potentiation of glucose-induced insulin secretion was demonstrated. It is also known that upon stimulation of insulin secretion, both rat and mouse islets release ATP. In rat islets, ATP undergoes extracellular conversion to adenosine. However, mouse islets are unable to convert extracellularly ATP to adenosine and adenosine arises from intracellular ATP degradation.
Collapse
Affiliation(s)
- Tomasz Szkudelski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska 35, 60-637, Poznan, Poland,
| | | |
Collapse
|
37
|
Impairment of brain mitochondrial charybdotoxin- and ATP-insensitive BK channel activities in diabetes. Neuromolecular Med 2014; 16:862-71. [PMID: 25344764 DOI: 10.1007/s12017-014-8334-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 10/17/2014] [Indexed: 12/22/2022]
Abstract
Existing evidence indicates an impairment of mitochondrial functions and alterations in potassium channel activities in diabetes. Because mitochondrial potassium channels have been involved in several mitochondrial functions including cytoprotection, apoptosis and calcium homeostasis, a study was carried out to consider whether the gating behavior of the mitochondrial ATP- and ChTx-insensitive Ca(2+)-activated potassium channel (mitoBKCa) is altered in a streptozotocin (STZ) model of diabetes. Using ion channel incorporation of brain mitochondrial inner membrane into the bilayer lipid membrane, we provide in this work evidence for modifications of the mitoBKCa ion permeation properties with channels from vesicles preparations coming from diabetic rats characterized by a significant decrease in conductance. More importantly, the open probability of channels from diabetic rats was reduced 1.5-2.5 fold compared to control, the most significant decrease being observed at depolarizing potentials. Because BKCa β4 subunit has been documented to left shift the BKCa channel voltage dependence curve in high Ca(2+) conditions, a Western blot analysis was undertaken where the expression of mitoBKCa α and β4 subunits was estimated using of anti-α and β4 subunit antibodies. Our results indicated a significant decrease in mitoBKCa β4 subunit expression coupled to a decrease in the expression of α subunit, an observation compatible with the observed decrease in Ca(2+) sensitivity. Our results thus demonstrate a modification in the mitoBKCa channel gating properties in membrane preparations coming from STZ model of diabetic rats, an effect potentially linked to a change in mitoBKCa β4 and α subunits expression and/or to an increase in reactive oxygen species production in high glucose conditions.
Collapse
|
38
|
Chandran S, Yap F, Hussain K. Molecular mechanisms of protein induced hyperinsulinaemic hypoglycaemia. World J Diabetes 2014; 5:666-677. [PMID: 25317244 PMCID: PMC4138590 DOI: 10.4239/wjd.v5.i5.666] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/23/2014] [Accepted: 05/29/2014] [Indexed: 02/05/2023] Open
Abstract
The interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids and fatty acids is critical for regulated insulin secretion. Mitochondrial metabolism of glucose, amino acid and fatty acids generates metabolic coupling factors (such as ATP, NADPH, glutamate, long chain acyl-CoA and diacylglycerol) which trigger insulin secretion. The observation of protein induced hypoglycaemia in patients with mutations in GLUD1 gene, encoding the enzyme glutamate dehydrogenase (GDH) and HADH gene, encoding for the enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase has provided new mechanistic insights into the regulation of insulin secretion by amino acid and fatty acid metabolism. Metabolic signals arising from amino acid and fatty acid metabolism converge on the enzyme GDH which integrates both signals from both pathways and controls insulin secretion. Hence GDH seems to play a pivotal role in regulating both amino acid and fatty acid metabolism.
Collapse
|
39
|
De Tata V. Association of dioxin and other persistent organic pollutants (POPs) with diabetes: epidemiological evidence and new mechanisms of beta cell dysfunction. Int J Mol Sci 2014; 15:7787-811. [PMID: 24802877 PMCID: PMC4057704 DOI: 10.3390/ijms15057787] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/16/2014] [Accepted: 04/21/2014] [Indexed: 12/23/2022] Open
Abstract
The worldwide explosion of the rates of diabetes and other metabolic diseases in the last few decades cannot be fully explained only by changes in the prevalence of classical lifestyle-related risk factors, such as physical inactivity and poor diet. For this reason, it has been recently proposed that other "nontraditional" risk factors could contribute to the diabetes epidemics. In particular, an increasing number of reports indicate that chronic exposure to and accumulation of a low concentration of environmental pollutants (especially the so-called persistent organic pollutants (POPs)) within the body might be associated with diabetogenesis. In this review, the epidemiological evidence suggesting a relationship between dioxin and other POPs exposure and diabetes incidence will be summarized, and some recent developments on the possible underlying mechanisms, with particular reference to dioxin, will be presented and discussed.
Collapse
Affiliation(s)
- Vincenzo De Tata
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma, 55, Scuola Medica, 56126 Pisa, Italy.
| |
Collapse
|
40
|
Chen X, Cui Z, Wei S, Hou J, Xie Z, Peng X, Li J, Cai T, Hang H, Yang F. Chronic high glucose induced INS-1β cell mitochondrial dysfunction: a comparative mitochondrial proteome with SILAC. Proteomics 2014; 13:3030-9. [PMID: 23956156 DOI: 10.1002/pmic.201200448] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 06/28/2013] [Accepted: 07/23/2013] [Indexed: 11/08/2022]
Abstract
As glucose-stimulated insulin secretion of pancreatic β cell is triggered and promoted by the metabolic messengers derived from mitochondria, mitochondria take a central stage in the normal function of β cells. β cells in diabetics were chronically exposed to hyperglycemia stimulation, which have been reported to exert deleterious effects on β-cell mitochondria. However, the mechanism of the toxic effects of hyperglycemia on β-cell mitochondria was not clear. In this study, we characterized the biological functional changes of rat INS-1β cells and their mitochondria with chronic exposure to hyperglycemia and created a research model of chronic hyperglycemia-induced dysfunctional β cells with damaged mitochondria. Then, SILAC-based quantitative proteomic approach was used to compare the mitochondrial protein expression from high glucose treated INS-1β cells and control cells. The expression of some mitochondrial proteins was found with significant changes. Functional classification revealed most of these proteins were related with oxidative phosphorylation, mitochondrial protein biosynthesis, substances metabolism, transport, and cell death. These results presented some useful information about the effect of glucotoxicity on the β-cell mitochondria.
Collapse
Affiliation(s)
- Xiulan Chen
- Laboratory of Protein and Peptide Pharmaceuticals, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; Laboratory of Proteomics, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Masini M, Anello M, Bugliani M, Marselli L, Filipponi F, Boggi U, Purrello F, Occhipinti M, Martino L, Marchetti P, De Tata V. Prevention by metformin of alterations induced by chronic exposure to high glucose in human islet beta cells is associated with preserved ATP/ADP ratio. Diabetes Res Clin Pract 2014; 104:163-70. [PMID: 24462282 DOI: 10.1016/j.diabres.2013.12.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 12/13/2013] [Accepted: 12/21/2013] [Indexed: 11/25/2022]
Abstract
AIM We have explored whether the insulin secretory defects induced by glucotoxicity in human pancreatic islets could be prevented by metformin and investigated some of the possible mechanisms involved. METHODS Human pancreatic islets and INS-1E cells were cultured for 24h with or without high glucose (16.7mM) concentration in the presence or absence of therapeutical concentration of metformin and then glucose-stimulated insulin release, adenine nucleotide levels and mitochondrial complex I and II activities were measured. Islet ultrastructure was analyzed by electron microscopy. RESULTS Compared to control islets, human islets cultured with high glucose showed a reduced glucose-stimulated insulin secretion that was associated with lower ATP levels and a lower ATP/ADP ratio. These functional and biochemical defects were significantly prevented by the presence of metformin in the culture medium, that was also able to significantly inhibit the activity of mitochondrial complex I especially in beta cells exposed to high glucose. Ultrastructural observations showed that mitochondrial volume density was significantly increased in high glucose cultured islets. The critical involvement of mitochondria was further supported by the observation of remarkably swollen organelles with dispersed matrix and fragmented cristae. Metformin was able to efficiently prevent the appearance of all these ultrastructural alterations in human islets exposed to high glucose. CONCLUSIONS Our results show that the functional, biochemical and ultrastructural abnormalities observed in human islet cells exposed to glucotoxic condition can be significantly prevented by metformin, further highlighting a direct beneficial effect of this drug on the insulin secreting human pancreatic beta cells.
Collapse
Affiliation(s)
- M Masini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - M Anello
- Department of Clinical and Molecular Biomedicine, University of Catania, Italy
| | - M Bugliani
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - L Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - F Filipponi
- Department of Surgical Pathology, Medicine, Molecular and Critical Area, University of Pisa, Italy
| | - U Boggi
- Department of Surgical Pathology, Medicine, Molecular and Critical Area, University of Pisa, Italy
| | - F Purrello
- Department of Clinical and Molecular Biomedicine, University of Catania, Italy
| | - M Occhipinti
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - L Martino
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - P Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - V De Tata
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy.
| |
Collapse
|
42
|
JEŽEK P, OLEJÁR T, SMOLKOVÁ K, JEŽEK J, DLASKOVÁ A, PLECITÁ-HLAVATÁ L, ZELENKA J, ŠPAČEK T, ENGSTOVÁ H, PAJUELO REGUERA D, JABŮREK M. Antioxidant and Regulatory Role of Mitochondrial Uncoupling Protein UCP2 in Pancreatic β-cells. Physiol Res 2014; 63:S73-91. [DOI: 10.33549/physiolres.932633] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Research on brown adipose tissue and its hallmark protein, mitochondrial uncoupling protein UCP1, has been conducted for half a century and has been traditionally studied in the Institute of Physiology (AS CR, Prague), likewise UCP2 residing in multiple tissues for the last two decades. Our group has significantly contributed to the elucidation of UCP uncoupling mechanism, fully dependent on free fatty acids (FFAs) within the inner mitochondrial membrane. Now we review UCP2 physiological roles emphasizing its roles in pancreatic β-cells, such as antioxidant role, possible tuning of redox homeostasis (consequently UCP2 participation in redox regulations), and fine regulation of glucose-stimulated insulin secretion (GSIS). For example, NADPH has been firmly established as being a modulator of GSIS and since UCP2 may influence redox homeostasis, it likely affects NADPH levels. We also point out the role of phospholipase iPLA2 isoform in providing FFAs for the UCP2 antioxidant function. Such initiation of mild uncoupling hypothetically precedes lipotoxicity in pancreatic β-cells until it reaches the pathological threshold, after which the antioxidant role of UCP2 can be no more cell-protective, for example due to oxidative stress-accumulated mutations in mtDNA. These mechanisms, together with impaired autocrine insulin function belong to important causes of Type 2 diabetes etiology.
Collapse
Affiliation(s)
- P. JEŽEK
- Department of Membrane Transport Biophysics, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
De Tata V. Age-related impairment of pancreatic Beta-cell function: pathophysiological and cellular mechanisms. Front Endocrinol (Lausanne) 2014; 5:138. [PMID: 25232350 PMCID: PMC4153315 DOI: 10.3389/fendo.2014.00138] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/07/2014] [Indexed: 12/13/2022] Open
Abstract
The incidence of type 2 diabetes significantly increases with age. The relevance of this association is dramatically magnified by the concomitant global aging of the population, but the underlying mechanisms remain to be fully elucidated. Here, some recent advances in this field are reviewed at the level of both the pathophysiology of glucose homeostasis and the cellular senescence of pancreatic islets. Overall, recent results highlight the crucial role of beta-cell dysfunction in the age-related impairment of pancreatic endocrine function and delineate the possibility of new original therapeutic interventions.
Collapse
Affiliation(s)
- Vincenzo De Tata
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- *Correspondence: Vincenzo De Tata, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma, 55 Scuola Medica, Pisa 56126, Italy e-mail:
| |
Collapse
|
44
|
Abstract
Mathematical modeling of the electrical activity of the pancreatic β-cell has been extremely important for understanding the cellular mechanisms involved in glucose-stimulated insulin secretion. Several models have been proposed over the last 30 y, growing in complexity as experimental evidence of the cellular mechanisms involved has become available. Almost all the models have been developed based on experimental data from rodents. However, given the many important differences between species, models of human β-cells have recently been developed. This review summarizes how modeling of β-cells has evolved, highlighting the proposed physiological mechanisms underlying β-cell electrical activity.
Collapse
Key Words
- ADP, adenosine diphosphate
- ATP, adenosine triphosphate
- CK, Chay-Keizer
- CRAC, calcium release-activated current
- Ca2+, calcium ions
- DOM, dual oscillator model
- ER, endoplasmic reticulum
- F6P, fructose-6-phosphate
- FBP, fructose-1,6-bisphosphate
- GLUT, glucose transporter
- GSIS, glucose-stimulated insulin secretion
- HERG, human eter à-go-go related gene
- IP3R, inositol-1,4,5-trisphosphate receptors
- KATP, ATP-sensitive K+ channels
- KCa, Ca2+-dependent K+ channels
- Kv, voltage-dependent K+ channels
- MCU, mitochondrial Ca2+ uniporter
- NCX, Na+/Ca2+ exchanger
- PFK, phosphofructokinase
- PMCA, plasma membrane Ca2+-ATPase
- ROS, reactive oxygen species
- RyR, ryanodine receptors
- SERCA, sarco-endoplasmic reticulum Ca2+-ATPase
- T2D, Type 2 Diabetes
- TCA, trycarboxylic acid cycle
- TRP, transient receptor potential
- VDCC, voltage-dependent Ca2+ channels
- Vm, membrane potential
- [ATP]i, cytosolic ATP
- [Ca2+]i, intracellular calcium concentration
- [Ca2+]m, mitochondrial calcium
- [Na+], Na+ concentration
- action potentials
- bursting
- cAMP, cyclic AMP
- calcium
- electrical activity
- ion channels
- mNCX, mitochondrial Na+/Ca2+ exchanger
- mathematical model
- β-cell
Collapse
Affiliation(s)
- Gerardo J Félix-Martínez
- Department of Electrical Engineering; Universidad
Autónoma Metropolitana-Iztapalapa; México, DF,
México
- Correspondence to: Gerardo J
Félix-Martínez;
| | | |
Collapse
|
45
|
Martino L, Masini M, Novelli M, Giacopelli D, Beffy P, Masiello P, De Tata V. The aryl receptor inhibitor epigallocatechin-3-gallate protects INS-1E beta-cell line against acute dioxin toxicity. CHEMOSPHERE 2013; 93:1447-1455. [PMID: 24050715 DOI: 10.1016/j.chemosphere.2013.06.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 05/27/2013] [Accepted: 06/02/2013] [Indexed: 06/02/2023]
Abstract
The aim of this research was to investigate the mechanism(s) underlying the acute toxicity of dioxin in pancreatic beta cells and to evaluate the protective effects of epigallocatechin-3-gallate (EGCG), the most abundant of the green tea's catechins and a powerful inhibitor of the aryl hydrocarbon receptor (AhR). Using the insulin-secreting INS-1E cell line we have explored the effect of 1h exposure to different concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), alone or in the presence of EGCG, on: (a) cell survival; (b) cellular ultrastructure; (c) intracellular calcium levels; (d) mitochondrial membrane potential; (e) glucose-stimulated insulin secretion and (f) activation of MAP kinases. Our results demonstrate that TCDD is highly toxic for INS-1E cells, suggesting that pancreatic beta cells should be considered a relevant and sensitive target for dioxin acute toxicity. EGCG significantly protects INS-1E cells against TCDD-induced toxicity in terms of both cell survival and preservation of cellular ultrastructure. The mechanism of this protective effect seems to be related to: (a) the ability of EGCG to preserve the mitochondrial function and thus to prevent the TCDD-induced inhibition of glucose-stimulated insulin secretion and (b) the ability of EGCG to inhibit the TCDD-induced activation of selected kinases, such as e.g. ERK 1/2 and JNK. Our results clearly show that EGCG is able to protect pancreatic beta cells against dioxin acute toxicity and indicate the mitochondrion as the most likely target for this beneficial effect.
Collapse
Affiliation(s)
- L Martino
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, I-56126 Pisa, Italy
| | | | | | | | | | | | | |
Collapse
|
46
|
Maechler P. Mitochondrial function and insulin secretion. Mol Cell Endocrinol 2013; 379:12-8. [PMID: 23792187 DOI: 10.1016/j.mce.2013.06.019] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 06/12/2013] [Accepted: 06/12/2013] [Indexed: 10/26/2022]
Abstract
In the endocrine fraction of the pancreas, the β-cell rapidly reacts to fluctuations in blood glucose concentrations by adjusting the rate of insulin secretion. Glucose-sensing coupled to insulin exocytosis depends on transduction of metabolic signals into intracellular messengers recognized by the secretory machinery. Mitochondria play a central role in this process by connecting glucose metabolism to insulin release. Mitochondrial activity is primarily regulated by metabolic fluxes, but also by dynamic morphology changes and free Ca(2+) concentrations. Recent advances of mitochondrial Ca(2+) homeostasis are discussed; in particular the roles of the newly-identified mitochondrial Ca(2+) uniporter MCU and its regulatory partner MICU1, as well as the mitochondrial Na(+)-Ca(2+) exchanger. This review describes how mitochondria function both as sensors and generators of metabolic signals; such as NADPH, long chain acyl-CoA, glutamate. The coupling factors are additive to the Ca(2+) signal and participate to the amplifying pathway of glucose-stimulated insulin secretion.
Collapse
Affiliation(s)
- Pierre Maechler
- Department of Cell Physiology and Metabolism, Geneva University Medical Centre, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland.
| |
Collapse
|
47
|
Wallace M, Whelan H, Brennan L. Metabolomic analysis of pancreatic beta cells following exposure to high glucose. Biochim Biophys Acta Gen Subj 2013; 1830:2583-90. [PMID: 23153904 DOI: 10.1016/j.bbagen.2012.10.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 10/03/2012] [Accepted: 10/29/2012] [Indexed: 11/17/2022]
Abstract
BACKGROUND Chronic exposure to hyperglycaemic conditions has been shown to have detrimental effects on beta cell function. The resulting glucotoxicity is a contributing factor to the development of type 2 diabetes. The objective of this study was to combine a metabolomics approach with functional assays to gain insight into the mechanism by which glucotoxicity exerts its effects. METHODS The BRIN-BD11 and INS-1E beta cell lines were cultured in 25 mM glucose for 20 h to mimic glucotoxic effects. PDK-2 protein expression, intracellular glutathione levels and the change in mitochondrial membrane potential and intracellular calcium following glucose stimulation were determined. Metabolomic analysis of beta cell metabolite extracts was performed using GC-MS, 1H NMR and 13C NMR. RESULTS Conditions to mimic glucotoxicity were established and resulted in no loss of cellular viability in either cell line while causing a decrease in insulin secretion. Metabolomic analysis of beta cells following exposure to high glucose revealed a change in amino acids, an increase in glucose and a decrease in phospho-choline, n-3 and n-6 PUFAs during glucose stimulated insulin secretion relative to cells cultured under control conditions. However, no changes in calcium handling or mitochondrial membrane potential were evident. CONCLUSIONS Results indicate that a decrease in TCA cycle metabolism in combination with an alteration in fatty acid composition and phosphocholine levels may play a role in glucotoxicity induced impairment of glucose stimulated insulin secretion. GENERAL SIGNIFICANCE Alterations in certain metabolic pathways play a role in glucotoxicity in the pancreatic beta cell.
Collapse
Affiliation(s)
- Martina Wallace
- UCD Conway Institute, UCD School of Agriculture, Food Science and Veterinary Medicine, UCD, Belfield, Dublin 4, Ireland
| | | | | |
Collapse
|
48
|
Ilahi I, Asghar A, Ali S, Khan M, Khan N. Beneficial Effects of Pentanema vestitum Linn. Whole Plant on the Glucose and Other Biochemical Parameters of Alloxan Induced Diabetic Rabbits. ISRN PHARMACOLOGY 2012; 2012:478023. [PMID: 23316385 PMCID: PMC3539413 DOI: 10.5402/2012/478023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/12/2012] [Indexed: 11/23/2022]
Abstract
The residents of Lower Dir and Malakand agency, Khyber Pakhtunkhwa, Pakistan, use the dry powder of whole plant of Pentanema vestitum for the treatment of asthma and diabetes. No documented reports are available about the therapeutic action of Pentanema vestitum. The present study was aimed to explore the antihyperglycemic effect of 70% methanol extract of Pentanema vestitum whole plant in glucose-induced nondiabetic hyperglycemic and alloxan-induced diabetic rabbits. During this study, the effects of plant extract on the serum lipid profile, GPT, ALP, bilirubin and creatinine of diabetic rabbits were also studied. The extract of Pentanema vestitum whole plant exhibited significant (P < 0.05) antihyperglycemic activity in glucose-induced hyperglycemic rabbits. Treatment of alloxan-induced diabetic rabbits with extract significantly (P < 0.05) reduced the elevated levels of serum glucose, GPT, ALP, bilirubin and creatinine. During the study of lipid profile, the extract proved to be antihyperlipidemic and HDL boosting in diabetic rabbit models. From the finding of the present research, it was concluded that the 70% methanol extract of Pentanema vestitum whole plant has beneficial effects on serum levels of glucose, lipid profile, GPT, ALP, bilirubin, and creatinine of diabetic rabbits.
Collapse
Affiliation(s)
- Ikram Ilahi
- Department of Zoology, University of Malakand, Chakdara, Dir Lower 25000, Khyber Pakhtunkhwa, Pakistan
| | | | | | | | | |
Collapse
|
49
|
Redox homeostasis in pancreatic β cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:932838. [PMID: 23304259 PMCID: PMC3532876 DOI: 10.1155/2012/932838] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 10/30/2012] [Indexed: 12/20/2022]
Abstract
We reviewed mechanisms that determine reactive oxygen species (redox) homeostasis, redox information signaling and metabolic/regulatory function of autocrine insulin signaling in pancreatic β cells, and consequences of oxidative stress and dysregulation of redox/information signaling for their dysfunction. We emphasize the role of mitochondrion in β cell molecular physiology and pathology, including the antioxidant role of mitochondrial uncoupling protein UCP2. Since in pancreatic β cells pyruvate cannot be easily diverted towards lactate dehydrogenase for lactate formation, the respiration and oxidative phosphorylation intensity are governed by the availability of glucose, leading to a certain ATP/ADP ratio, whereas in other cell types, cell demand dictates respiration/metabolism rates. Moreover, we examine the possibility that type 2 diabetes mellitus might be considered as an inevitable result of progressive self-accelerating oxidative stress and concomitantly dysregulated information signaling in peripheral tissues as well as in pancreatic β cells. It is because the redox signaling is inherent to the insulin receptor signaling mechanism and its impairment leads to the oxidative and nitrosative stress. Also emerging concepts, admiting participation of redox signaling even in glucose sensing and insulin release in pancreatic β cells, fit in this view. For example, NADPH has been firmly established to be a modulator of glucose-stimulated insulin release.
Collapse
|
50
|
Abstract
Mitochondria are membrane bound organelles present in almost all eukaryotic cells. Responsible for orchestrating cellular energy production, they are central to the maintenance of life and the gatekeepers of cell death. Thought to have originated from symbiotic ancestors, they carry a residual genome as mtDNA encoding 13 proteins essential for respiratory chain function. Mitochondria comprise an inner and outer membrane that separate and maintain the aqueous regions, the intermembrane space and the matrix. Mitochondria contribute to many processes central to cellular function and dysfunction including calcium signalling, cell growth and differentiation, cell cycle control and cell death. Mitochondrial shape and positioning in cells is crucial and is tightly regulated by processes of fission and fusion, biogenesis and autophagy, ensuring a relatively constant mitochondrial population. Mitochondrial dysfunction is implicated in metabolic and age related disorders, neurodegenerative diseases and ischemic injury in heart and brain.
Collapse
Affiliation(s)
- Laura D. Osellame
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- UK Parkinson’s Disease Consortium, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - Thomas S. Blacker
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
- UK Parkinson’s Disease Consortium, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
- Corresponding author. Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom. Tel.: +44 20 7679 3207.
| |
Collapse
|