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Grubelnik V, Zmazek J, Gosak M, Marhl M. The role of anaplerotic metabolism of glucose and glutamine in insulin secretion: A model approach. Biophys Chem 2024; 311:107270. [PMID: 38833963 DOI: 10.1016/j.bpc.2024.107270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 05/22/2024] [Accepted: 05/22/2024] [Indexed: 06/06/2024]
Abstract
We propose a detailed computational beta cell model that emphasizes the role of anaplerotic metabolism under glucose and glucose-glutamine stimulation. This model goes beyond the traditional focus on mitochondrial oxidative phosphorylation and ATP-sensitive K+ channels, highlighting the predominant generation of ATP from phosphoenolpyruvate in the vicinity of KATP channels. It also underlines the modulatory role of H2O2 as a signaling molecule in the first phase of glucose-stimulated insulin secretion. In the second phase, the model emphasizes the critical role of anaplerotic pathways, activated by glucose stimulation via pyruvate carboxylase and by glutamine via glutamate dehydrogenase. It particularly focuses on the production of NADPH and glutamate as key enhancers of insulin secretion. The predictions of the model are consistent with empirical data, highlighting the complex interplay of metabolic pathways and emphasizing the primary role of glucose and the facilitating role of glutamine in insulin secretion. By delineating these crucial metabolic pathways, the model provides valuable insights into potential therapeutic targets for diabetes.
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Affiliation(s)
- Vladimir Grubelnik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Koroška cesta 46, 2000 Maribor, Slovenia
| | - Jan Zmazek
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia
| | - Marko Gosak
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia; Faculty of Medicine, University of Maribor, Taborska ulica 8, 2000 Maribor, Slovenia; Alma Mater Europaea ECM, Slovenska ulica 17, 2000 Maribor, Slovenia
| | - Marko Marhl
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia; Faculty of Medicine, University of Maribor, Taborska ulica 8, 2000 Maribor, Slovenia; Faculty of Education, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia.
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Zhou M, Hanschmann EM, Römer A, Linn T, Petry SF. The significance of glutaredoxins for diabetes mellitus and its complications. Redox Biol 2024; 71:103043. [PMID: 38377787 PMCID: PMC10891345 DOI: 10.1016/j.redox.2024.103043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/13/2024] [Indexed: 02/22/2024] Open
Abstract
Diabetes mellitus is a non-communicable metabolic disease hallmarked by chronic hyperglycemia caused by beta-cell failure. Diabetic complications affect the vasculature and result in macro- and microangiopathies, which account for a significantly increased morbidity and mortality. The rising incidence and prevalence of diabetes is a major global health burden. There are no feasible strategies for beta-cell preservation available in daily clinical practice. Therefore, patients rely on antidiabetic drugs or the application of exogenous insulin. Glutaredoxins (Grxs) are ubiquitously expressed and highly conserved members of the thioredoxin family of proteins. They have specific functions in redox-mediated signal transduction, iron homeostasis and biosynthesis of iron-sulfur (FeS) proteins, and the regulation of cell proliferation, survival, and function. The involvement of Grxs in chronic diseases has been a topic of research for several decades, suggesting them as therapeutic targets. Little is known about their role in diabetes and its complications. Therefore, this review summarizes the available literature on the significance of Grxs in diabetes and its complications. In conclusion, Grxs are differentially expressed in the endocrine pancreas and in tissues affected by diabetic complications, such as the heart, the kidneys, the eye, and the vasculature. They are involved in several pathways essential for insulin signaling, metabolic inflammation, glucose and fatty acid uptake and processing, cell survival, and iron and mitochondrial metabolism. Most studies describe significant changes in glutaredoxin expression and/or activity in response to the diabetic metabolism. In general, mitigated levels of Grxs are associated with oxidative distress, cell damage, and even cell death. The induced overexpression is considered a potential part of the cellular stress-response, counteracting oxidative distress and exerting beneficial impact on cell function such as insulin secretion, cytokine expression, and enzyme activity.
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Affiliation(s)
- Mengmeng Zhou
- Clinical Research Unit, Medical Clinic and Polyclinic III, Center of Internal Medicine, Justus Liebig University, Giessen, Germany
| | - Eva-Maria Hanschmann
- Experimental and Translational Research, Department of Otorhinolaryngology, University Hospital Essen, Essen, Germany
| | - Axel Römer
- Clinical Research Unit, Medical Clinic and Polyclinic III, Center of Internal Medicine, Justus Liebig University, Giessen, Germany
| | - Thomas Linn
- Clinical Research Unit, Medical Clinic and Polyclinic III, Center of Internal Medicine, Justus Liebig University, Giessen, Germany
| | - Sebastian Friedrich Petry
- Clinical Research Unit, Medical Clinic and Polyclinic III, Center of Internal Medicine, Justus Liebig University, Giessen, Germany.
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Chen Y, Zhao W, Hu A, Lin S, Chen P, Yang B, Fan Z, Qi J, Zhang W, Gao H, Yu X, Chen H, Chen L, Wang H. Type 2 diabetic mellitus related osteoporosis: focusing on ferroptosis. J Transl Med 2024; 22:409. [PMID: 38693581 PMCID: PMC11064363 DOI: 10.1186/s12967-024-05191-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 04/12/2024] [Indexed: 05/03/2024] Open
Abstract
With the aging global population, type 2 diabetes mellitus (T2DM) and osteoporosis(OP) are becoming increasingly prevalent. Diabetic osteoporosis (DOP) is a metabolic bone disorder characterized by abnormal bone tissue structure and reduced bone strength in patients with diabetes. Studies have revealed a close association among diabetes, increased fracture risk, and disturbances in iron metabolism. This review explores the concept of ferroptosis, a non-apoptotic cell death process dependent on intracellular iron, focusing on its role in DOP. Iron-dependent lipid peroxidation, particularly impacting pancreatic β-cells, osteoblasts (OBs) and osteoclasts (OCs), contributes to DOP. The intricate interplay between iron dysregulation, which comprises deficiency and overload, and DOP has been discussed, emphasizing how excessive iron accumulation triggers ferroptosis in DOP. This concise overview highlights the need to understand the complex relationship between T2DM and OP, particularly ferroptosis. This review aimed to elucidate the pathogenesis of ferroptosis in DOP and provide a prospective for future research targeting interventions in the field of ferroptosis.
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Affiliation(s)
- Yili Chen
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Wen Zhao
- Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510006, China
| | - An Hu
- Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510006, China
| | - Shi Lin
- Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510006, China
| | - Ping Chen
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Bing Yang
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Zhirong Fan
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Ji Qi
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Wenhui Zhang
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Huanhuan Gao
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Xiubing Yu
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Haiyun Chen
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Luyuan Chen
- Stomatology Center, Shenzhen Hospital, Southern Medical University, Shenzhen, Guangdong, 510086, China.
| | - Haizhou Wang
- Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
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Krishna A, Renu K. Elucidating the Role of Pelargonidin-3-O-Glucoside on C1QL3, CYBB, and CYTIP Involved in Glucose Metabolism: An In Silico Approach. JOURNAL OF PHARMACY AND BIOALLIED SCIENCES 2024; 16:S1299-S1303. [PMID: 38882825 PMCID: PMC11174306 DOI: 10.4103/jpbs.jpbs_590_23] [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: 08/12/2023] [Revised: 10/06/2023] [Accepted: 11/17/2023] [Indexed: 06/18/2024] Open
Abstract
Aim The metabolism of glucose is carefully regulated by several chemical elements and plays a critical part in preserving cellular energy balance. Our study investigates possible connections between the essential proteins CYTIP, C1QL3, and CYBB, which are involved in the metabolism of glucose, and pelargonidin, a naturally occurring plant chemical. The underlying mechanisms of pelargonidin's anti-diabetic effects are still unknown. Materials and Methods We examine the binding affinities and possible binding sites between pelargonidin and C1QL3/CYBB AND CYTIP using molecular docking simulations. The results demonstrate favorable docking scores and potential binding sites, suggesting the formation of stable complexes between pelargonidin and the target proteins. Results This finding means that pelargonidin may modulate the function of C1QL3 and CYBB, CYTIP consequently influencing glucose metabolism. Conclusion This study provides a foundation for future experimental investigations to validate the predicted interactions and explore the mechanisms through which pelargonidin affects glucose metabolism. Understanding these molecular interactions could lead to the development of new therapeutic strategies for glucose metabolism and its related disorders.
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Affiliation(s)
- Aravind Krishna
- Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India
| | - Kaviyarasi Renu
- Centre of Molecular Medicine and Diagnostics (COMManD), Department of Biochemistry, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India
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Gleason N, Williams CL, Kowluru A. Novel regulatory roles of small G protein GDP dissociation stimulator (smgGDS) in insulin secretion from pancreatic β-cells. Mol Cell Endocrinol 2024; 580:112104. [PMID: 38013223 PMCID: PMC10842139 DOI: 10.1016/j.mce.2023.112104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/26/2023] [Accepted: 10/28/2023] [Indexed: 11/29/2023]
Abstract
Emerging evidence implicates novel roles for small G protein GDP dissociation stimulator (smgGDS) in G protein activation and subsequent targeting to relevant subcellular compartments for effector regulation. Given the well-established roles of small G proteins in insulin secretion, we undertook this investigation to determine the putative roles of smgGDS in insulin secretion. Immunoblotting studies revealed that both splice variants of smgGDS are expressed in human islets, rat islets and INS-1 832/13 cells. A significant inhibition (-52%) of glucose-stimulated insulin secretion (GSIS) was observed in INS-1 832/13 cells following siRNA-mediated depletion of smgGDS. In addition, insulin secretion elicited by a membrane depolarizing concentration of KCl (via increased calcium influx), forskolin (via increased cAMP generation) or IBMX (via inhibition of phosphodiesterase) was inhibited by -49%, -27%, and -28%, respectively. Subcellular distribution studies revealed no significant alterations in the abundance of smgGDS in the cytosolic and membrane fractions during the 45-min exposure of INS-1 832/13 cells to an insulinotropic concentration of glucose. Together, we present the first evidence of expression of smgGDS in human islets, rodent islets, and clonal β-cells. We also demonstrate novel regulatory roles of these proteins in insulin secretion derived from glucose metabolic events, including calcium- and cAMP-dependent signaling steps.
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Affiliation(s)
- Noah Gleason
- Research Service, John D. Dingell VA Medical Center, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| | - Carol L Williams
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Anjaneyulu Kowluru
- Research Service, John D. Dingell VA Medical Center, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA.
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Martemucci G, Fracchiolla G, Muraglia M, Tardugno R, Dibenedetto RS, D’Alessandro AG. Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases. Antioxidants (Basel) 2023; 12:2091. [PMID: 38136211 PMCID: PMC10740837 DOI: 10.3390/antiox12122091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/15/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023] Open
Abstract
Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.
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Affiliation(s)
- Giovanni Martemucci
- Department of Agricultural and Environmental Sciences, University of Bari Aldo Moro, 70126 Bari, Italy;
| | - Giuseppe Fracchiolla
- Department of Pharmacy–Drug Sciences, University of Bari Aldo Moro, 70126 Bari, Italy; (M.M.); (R.T.); (R.S.D.)
| | - Marilena Muraglia
- Department of Pharmacy–Drug Sciences, University of Bari Aldo Moro, 70126 Bari, Italy; (M.M.); (R.T.); (R.S.D.)
| | - Roberta Tardugno
- Department of Pharmacy–Drug Sciences, University of Bari Aldo Moro, 70126 Bari, Italy; (M.M.); (R.T.); (R.S.D.)
| | - Roberta Savina Dibenedetto
- Department of Pharmacy–Drug Sciences, University of Bari Aldo Moro, 70126 Bari, Italy; (M.M.); (R.T.); (R.S.D.)
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Kowluru A. Regulatory roles of CARD9-BCL10-Rac1 (CBR) signalome in islet β-cell function in health and metabolic stress: Is there room for MALT1? Biochem Pharmacol 2023; 218:115889. [PMID: 37991197 PMCID: PMC10872519 DOI: 10.1016/j.bcp.2023.115889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/23/2023]
Abstract
It is widely accepted that pancreatic islet β-cell failure and the onset of type 2 diabetes (T2DM) constitute an intricate interplay between the genetic expression of the disease and a host of intracellular events including increased metabolic (oxidative, endoplasmic reticulum) stress under the duress of glucolipotoxicity. Emerging evidence implicates unique roles for Caspase Recruitment Domain containing protein 9 (CARD9) in the onset of metabolic diseases, including obesity and insulin resistance. Mechanistically, CARD9 has been implicated in the regulation of p38MAPK and NFkB signaling pathways culminating in cellular dysfunction. Several regulatory factors, including B-cell lymphoma/leukemia 10 (BCL10) have been identified as modulators of CARD9 function in multiple cell types. Despite this evidence on regulatory roles of CARD9-BCL10 signalome in the onset of various pathological states, putative roles of this signaling module in islet β-cell dysfunction in metabolic stress remain less understood. This brief review is aimed at highlighting roles for CARD9 in islet β-cell function under acute (physiological insulin secretion) and long-term (cell dysfunction) exposure to glucose. Emerging roles of other signaling proteins, such as Rac1, BCL10 and MALT1 as contributors to CARD9 signaling in the islet β-cells are also reviewed. Potential avenues for future research toward the development of novel therapeutics for the prevention CARD9-BCL10-Rac1 (CBR) signalome-induced β-cell defects under metabolic stress are discussed.
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Affiliation(s)
- Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
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Azarova I, Polonikov A, Klyosova E. Molecular Genetics of Abnormal Redox Homeostasis in Type 2 Diabetes Mellitus. Int J Mol Sci 2023; 24:ijms24054738. [PMID: 36902173 PMCID: PMC10003739 DOI: 10.3390/ijms24054738] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/20/2023] [Accepted: 02/24/2023] [Indexed: 03/05/2023] Open
Abstract
Numerous studies have shown that oxidative stress resulting from an imbalance between the production of free radicals and their neutralization by antioxidant enzymes is one of the major pathological disorders underlying the development and progression of type 2 diabetes (T2D). The present review summarizes the current state of the art advances in understanding the role of abnormal redox homeostasis in the molecular mechanisms of T2D and provides comprehensive information on the characteristics and biological functions of antioxidant and oxidative enzymes, as well as discusses genetic studies conducted so far in order to investigate the contribution of polymorphisms in genes encoding redox state-regulating enzymes to the disease pathogenesis.
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Affiliation(s)
- Iuliia Azarova
- Department of Biological Chemistry, Kursk State Medical University, 3 Karl Marx Street, 305041 Kursk, Russia
- Laboratory of Biochemical Genetics and Metabolomics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya Street, 305041 Kursk, Russia
| | - Alexey Polonikov
- Laboratory of Statistical Genetics and Bioinformatics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya Street, 305041 Kursk, Russia
- Department of Biology, Medical Genetics and Ecology, Kursk State Medical University, 3 Karl Marx Street, 305041 Kursk, Russia
- Correspondence:
| | - Elena Klyosova
- Laboratory of Biochemical Genetics and Metabolomics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya Street, 305041 Kursk, Russia
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Elumalai S, Karunakaran U, Won KC, Chung SM, Moon JS. Perfluorooctane sulfonate-induced oxidative stress contributes to pancreatic β-cell apoptosis by inhibiting cyclic adenosine monophosphate pathway: Prevention by pentoxifylline. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 320:120959. [PMID: 36621715 DOI: 10.1016/j.envpol.2022.120959] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/18/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
Endocrine-disrupting chemical perfluorooctane sulfonate (PFOS) acute exposure stimulates insulin secretion from pancreatic β-cells. However, chronic exposure to PFOS on pancreatic β-cells, its role in insulin secretion, and the underlying mechanisms have not been studied. We used rat insulinoma INS-1 and human 1.1b4 islet cells to investigate the chronic effects of PFOS on glucose-stimulated insulin secretion and toxicity implicated in the downregulation of β-cell functionality. Chronic exposure of INS-1 cells or human pancreatic 1.1b4 β-cells to PFOS stimulated the small G-protein RAC1-guanosine triphosphate-dependent nicotinamide adenine dinucleotide phosphate oxidase (NOX2/gp91phox) subunit expression and activation. Upregulated NOX2/gp91phox activation led to elevated reactive oxygen species (ROS) production with a decrease in the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway in both cell types. Inhibition of cAMP/PKA signaling induces β-cell mitochondrial dysfunction and endoplasmic stress via the loss of PDX1-SERCA2B and glucose-stimulated insulin release. Inhibiting RAC1-NOX2/gp91phox activation or elevating cAMP by pentoxifylline, a Food and Drug Administration-approved phosphodiesterase inhibitor, significantly reduced PFOS-induced ROS production and restored insulin secretory function of pancreatic β-cells. Enhanced secretory function in pentoxifylline-treated cells was associated with increased stability of PDX1-SERCA2B protein levels. Intriguingly, inhibition of cAMP/PKA signaling impaired pentoxifylline-induced insulin secretion caused by the activation of ROS production and mitochondrial dysfunction. Overall, our findings show that PFOS has a new and first-ever direct chronic effect on pancreatic β-cell failure through increased RAC1-NOX2/gp91phox activation and pentoxifylline-induced cAMP/PKA signaling, which inhibits PFOS-mediated mitochondrial dysfunction.
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Affiliation(s)
- Suma Elumalai
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu, Republic of Korea
| | - Udayakumar Karunakaran
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu, Republic of Korea
| | - Kyu Chang Won
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu, Republic of Korea; Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Seung Min Chung
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu, Republic of Korea; Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Jun Sung Moon
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea.
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Type 2 Diabetes and Alzheimer's Disease: The Emerging Role of Cellular Lipotoxicity. Biomolecules 2023; 13:biom13010183. [PMID: 36671568 PMCID: PMC9855893 DOI: 10.3390/biom13010183] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Type 2 diabetes (T2D) and Alzheimer's diseases (AD) represent major health issues that have reached alarming levels in the last decades. Although growing evidence demonstrates that AD is a significant comorbidity of T2D, and there is a ~1.4-2-fold increase in the risk of developing AD among T2D patients, the involvement of possible common triggers in the pathogenesis of these two diseases remains largely unknown. Of note, recent mechanistic insights suggest that lipotoxicity could represent the missing ring in the pathogenetic mechanisms linking T2D to AD. Indeed, obesity, which represents the main cause of lipotoxicity, has been recognized as a major risk factor for both pathological conditions. Lipotoxicity can lead to inflammation, insulin resistance, oxidative stress, ceramide and amyloid accumulation, endoplasmic reticulum stress, ferroptosis, and autophagy, which are shared biological events in the pathogenesis of T2D and AD. In the current review, we try to provide a critical and comprehensive view of the common molecular pathways activated by lipotoxicity in T2D and AD, attempting to summarize how these mechanisms can drive future research and open the way to new therapeutic perspectives.
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Elumalai S, Karunakaran U, Moon JS, Won KC. Ferroptosis Signaling in Pancreatic β-Cells: Novel Insights & Therapeutic Targeting. Int J Mol Sci 2022; 23:ijms232213679. [PMID: 36430158 PMCID: PMC9690757 DOI: 10.3390/ijms232213679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/02/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022] Open
Abstract
Metabolic stress impairs pancreatic β-cell survival and function in diabetes. Although the pathophysiology of metabolic stress is complex, aberrant tissue damage and β-cell death are brought on by an imbalance in redox equilibrium due to insufficient levels of endogenous antioxidant expression in β-cells. The vulnerability of β-cells to oxidative damage caused by iron accumulation has been linked to contributory β-cell ferroptotic-like malfunction under diabetogenic settings. Here, we take into account recent findings on how iron metabolism contributes to the deregulation of the redox response in diabetic conditions as well as the ferroptotic-like malfunction in the pancreatic β-cells, which may offer insights for deciphering the pathomechanisms and formulating plans for the treatment or prevention of metabolic stress brought on by β-cell failure.
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Affiliation(s)
- Suma Elumalai
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea
| | - Udayakumar Karunakaran
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea
| | - Jun-Sung Moon
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea
- Department of Internal Medicine, College of Medicine, Yeungnam University, Daegu 42415, Korea
- Correspondence: (J.-S.M.); (K.-C.W.); Tel.: +82-53-620-3825 (J.-S.W.); +82-53-620-3846 (K.-C.W.)
| | - Kyu-Chang Won
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea
- Department of Internal Medicine, College of Medicine, Yeungnam University, Daegu 42415, Korea
- Correspondence: (J.-S.M.); (K.-C.W.); Tel.: +82-53-620-3825 (J.-S.W.); +82-53-620-3846 (K.-C.W.)
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Hali M, Wadzinski BE, Kowluru A. Alpha4 contributes to the dysfunction of the pancreatic beta cell under metabolic stress. Mol Cell Endocrinol 2022; 557:111754. [PMID: 35987388 PMCID: PMC9620510 DOI: 10.1016/j.mce.2022.111754] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/10/2022] [Accepted: 08/12/2022] [Indexed: 11/30/2022]
Abstract
The current study examined the roles of Alpha4, a non-canonical subunit of protein phosphatase 2A, in the regulation of acute (insulin secretion) and chronic (cell dysfunction) effects of glucose in pancreatic beta cells. Alpha4 is expressed in human islets, rat islets and INS-1832/13 cells. Incubation of INS-1832/13 cells and rat islets with high glucose (HG) significantly increased the expression of Alpha4. C2-Ceramide, a biologically active sphingolipid, also increased the expression of Alpha4 in INS-1832/13 cells and rat islets. Subcellular distribution studies of Alpha4 in low glucose (LG) and HG exposed INS-1832/13 cells revealed that it is predominantly cytosolic, and its expression is significantly increased in the non-nuclear/cytosolic fractions in cells exposed to HG. siRNA-mediated knockdown of Alpha4 exerted minimal effects on glucose- or KCl-induced insulin secretion. siRNA-mediated deletion of Alpha4 significantly increased p38MAPK and JNK1/2 phosphorylation under LG conditions, comparable to the degree seen under HG conditions. Paradoxically, a significant potentiation of HG-induced p38MAPK and JNK2 phosphorylation was noted following Alpha4 deletion. HG-induced CHOP expression (ER stress marker) and caspase-3 activation were markedly attenuated in cells following Alpha4 knockdown. Deletion of Alpha4 in INS-1832/13 cells prevented HG-induced loss in the expression of Connexin36, a gap junction channel protein, which has been implicated in normal beta cell function. Lastly, depletion of endogenous Alpha4 significantly reduced HG-induced cell death in INS-1832/13 cells. Based on these findings we conclude that Alpha4 contributes to HG-induced metabolic dysfunction of the islet beta cell.
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Affiliation(s)
- Mirabela Hali
- Biomedical Research Service, John D. Dingell VA Medical Center, Detroit, MI, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| | - Brian E Wadzinski
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center, Detroit, MI, USA; Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA.
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Mukai E, Fujimoto S, Inagaki N. Role of Reactive Oxygen Species in Glucose Metabolism Disorder in Diabetic Pancreatic β-Cells. Biomolecules 2022; 12:biom12091228. [PMID: 36139067 PMCID: PMC9496160 DOI: 10.3390/biom12091228] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/28/2022] [Accepted: 08/31/2022] [Indexed: 11/18/2022] Open
Abstract
The dysfunction of pancreatic β-cells plays a central role in the onset and progression of type 2 diabetes mellitus (T2DM). Insulin secretory defects in β-cells are characterized by a selective impairment of glucose stimulation, and a reduction in glucose-induced ATP production, which is essential for insulin secretion. High glucose metabolism for insulin secretion generates reactive oxygen species (ROS) in mitochondria. In addition, the expression of antioxidant enzymes is very low in β-cells. Therefore, β-cells are easily exposed to oxidative stress. In islet studies using a nonobese T2DM animal model that exhibits selective impairment of glucose-induced insulin secretion (GSIS), quenching ROS generated by glucose stimulation and accumulated under glucose toxicity can improve impaired GSIS. Acute ROS generation and toxicity cause glucose metabolism disorders through different molecular mechanisms. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is a master regulator of antioxidant defense and a potential therapeutic target in oxidative stress-related diseases, suggesting the possible involvement of Nrf2 in β-cell dysfunction caused by ROS. In this review, we describe the mechanisms of insulin secretory defects induced by oxidative stress in diabetic β-cells.
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Affiliation(s)
- Eri Mukai
- Medical Physiology and Metabolism Laboratory, Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, Kusatsu 5258577, Japan
- Correspondence:
| | - Shimpei Fujimoto
- Department of Endocrinology, Metabolism, and Nephrology, Kochi Medical School, Kochi University, Kochi 7838505, Japan
| | - Nobuya Inagaki
- Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, Kyoto 6068507, Japan
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14
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Lu H, Yang J, Li J, Yuan H. MiR-190 ameliorates glucotoxicity-induced dysfunction and apoptosis of pancreatic β-cells by inhibiting NOX2-mediated reactive oxygen species production. PeerJ 2022; 10:e13849. [PMID: 35971429 PMCID: PMC9375543 DOI: 10.7717/peerj.13849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/15/2022] [Indexed: 01/18/2023] Open
Abstract
Glucotoxicity-induced pancreatic β-cell failure contributes to the development of type 2 diabetes mellitus (T2DM). Accumulating evidence reveals that miRNAs play a critical role in regulating pancreatic β-cell function and survival. In this study, we employed a self-assembled cell microarray (SAMcell)-based functional screening assay to identify miRNAs that are capable of regulating the dysfunction of β-cells induced by glucotoxicity. Among 62 conserved miRNAs we tested, miR-190 was identified as a candidate regulator that could effectively restore insulin expression in NIT-1 cells under high-glucose (HG) stimulation. Further analyses demonstrated that miR-190 was significantly down-regulated in HG-treated NIT-1 cells, as well as in the pancreas of diabetic mice. Mechanistic studies showed that Cybb is the direct target gene of miR-190, which encodes the gp91phox protein, a subunit of the NOX2 complex. Furthermore, both miR-190 overexpression and Cybb knockdown inhibited apoptosis and improved glucose-stimulated insulin secretion (GSIS) in HG-stimulated NIT-1 cells by attenuating the excessive production of reactive oxygen species (ROS). More importantly, a targeted delivery of mPEG-PCL-g-PDMAEMA nanoparticles/miR-190 complexes (PECgD NPs/miR-190) to the pancreas significantly ameliorated hyperglycemia, decreased fasting serum insulin levels, and improved glucose tolerance in diabetic mice. Taken together, our findings suggest that the miR-190/Cybb axis plays an important role in glucotoxicity-induced pancreatic β-cell failure. Restoring miR-190 expression levels may be a possible therapeutic strategy to protect β-cells in T2DM.
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Affiliation(s)
- Huinan Lu
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, P.R. China,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China,Peking-Tsinghua Center for Life Sciences, Beijing, China,Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
| | - Junyu Yang
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
| | - Juan Li
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, China
| | - Huiping Yuan
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology of National Health Commission, Beijing, P.R. China
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15
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Shehata AS, Zidan RA, El-Mahroky SM, Abd El-Baset SA. Efficacy of platelet rich plasma on pancreatic injury induced by renal ischemia reperfusion in adult male rats. Ultrastruct Pathol 2022; 46:188-203. [DOI: 10.1080/01913123.2022.2044945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Azza S. Shehata
- Department of Medical Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Rania A. Zidan
- Department of Medical Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Samaa M. El-Mahroky
- Department of Medical Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Samia A. Abd El-Baset
- Department of Medical Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
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16
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Newsholme P, Rowlands J, Rose’Meyer R, Cruzat V. Metabolic Adaptions/Reprogramming in Islet Beta-Cells in Response to Physiological Stimulators—What Are the Consequences. Antioxidants (Basel) 2022; 11:antiox11010108. [PMID: 35052612 PMCID: PMC8773416 DOI: 10.3390/antiox11010108] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/25/2022] Open
Abstract
Irreversible pancreatic β-cell damage may be a result of chronic exposure to supraphysiological glucose or lipid concentrations or chronic exposure to therapeutic anti-diabetic drugs. The β-cells are able to respond to blood glucose in a narrow concentration range and release insulin in response, following activation of metabolic pathways such as glycolysis and the TCA cycle. The β-cell cannot protect itself from glucose toxicity by blocking glucose uptake, but indeed relies on alternative metabolic protection mechanisms to avoid dysfunction and death. Alteration of normal metabolic pathway function occurs as a counter regulatory response to high nutrient, inflammatory factor, hormone or therapeutic drug concentrations. Metabolic reprogramming is a term widely used to describe a change in regulation of various metabolic enzymes and transporters, usually associated with cell growth and proliferation and may involve reshaping epigenetic responses, in particular the acetylation and methylation of histone proteins and DNA. Other metabolic modifications such as Malonylation, Succinylation, Hydroxybutyrylation, ADP-ribosylation, and Lactylation, may impact regulatory processes, many of which need to be investigated in detail to contribute to current advances in metabolism. By describing multiple mechanisms of metabolic adaption that are available to the β-cell across its lifespan, we hope to identify sites for metabolic reprogramming mechanisms, most of which are incompletely described or understood. Many of these mechanisms are related to prominent antioxidant responses. Here, we have attempted to describe the key β-cell metabolic adaptions and changes which are required for survival and function in various physiological, pathological and pharmacological conditions.
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Affiliation(s)
- Philip Newsholme
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Jordan Rowlands
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Roselyn Rose’Meyer
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia;
| | - Vinicius Cruzat
- Faculty of Health, Torrens University Australia, Brisbane, QLD 4006, Australia;
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17
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Sphingosine-1 Phosphate Lyase Regulates Sensitivity of Pancreatic Beta-Cells to Lipotoxicity. Int J Mol Sci 2021; 22:ijms221910893. [PMID: 34639233 PMCID: PMC8509761 DOI: 10.3390/ijms221910893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/28/2021] [Accepted: 10/04/2021] [Indexed: 12/29/2022] Open
Abstract
Elevated levels of free fatty acids (FFAs) have been related to pancreatic beta-cell failure in type 2 diabetes (T2DM), though the underlying mechanisms are not yet fully understood. FFAs have been shown to dysregulate formation of bioactive sphingolipids, such as ceramides and sphingosine-1 phosphate (S1P) in beta-cells. The aim of this study was to analyze the role of sphingosine-1 phosphate lyase (SPL), a key enzyme of the sphingolipid pathway that catalyzes an irreversible degradation of S1P, in the sensitivity of beta-cells to lipotoxicity. To validate the role of SPL in lipotoxicity, we modulated SPL expression in rat INS1E cells and in human EndoC-βH1 beta-cells. SPL overexpression in INS1E cells (INS1E-SPL), which are characterized by a moderate basal expression level of SPL, resulted in an acceleration of palmitate-mediated cell viability loss, proliferation inhibition and induction of oxidative stress. SPL overexpression affected the mRNA expression of ER stress markers and mitochondrial chaperones. In contrast to control cells, in INS1E-SPL cells no protective effect of oleate was detected. Moreover, Plin2 expression and lipid droplet formation were strongly reduced in OA-treated INS1E-SPL cells. Silencing of SPL in human EndoC-βH1 beta-cells, which are characterized by a significantly higher SPL expression as compared to rodent beta-cells, resulted in prevention of FFA-mediated caspase-3/7 activation. Our findings indicate that an adequate control of S1P degradation by SPL might be crucially involved in the susceptibility of pancreatic beta-cells to lipotoxicity.
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18
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Hampel H, Nisticò R, Seyfried NT, Levey AI, Modeste E, Lemercier P, Baldacci F, Toschi N, Garaci F, Perry G, Emanuele E, Valenzuela PL, Lucia A, Urbani A, Sancesario GM, Mapstone M, Corbo M, Vergallo A, Lista S. Omics sciences for systems biology in Alzheimer's disease: State-of-the-art of the evidence. Ageing Res Rev 2021; 69:101346. [PMID: 33915266 DOI: 10.1016/j.arr.2021.101346] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 04/06/2021] [Accepted: 04/22/2021] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is characterized by non-linear, genetic-driven pathophysiological dynamics with high heterogeneity in biological alterations and disease spatial-temporal progression. Human in-vivo and post-mortem studies point out a failure of multi-level biological networks underlying AD pathophysiology, including proteostasis (amyloid-β and tau), synaptic homeostasis, inflammatory and immune responses, lipid and energy metabolism, oxidative stress. Therefore, a holistic, systems-level approach is needed to fully capture AD multi-faceted pathophysiology. Omics sciences - genomics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics - embedded in the systems biology (SB) theoretical and computational framework can generate explainable readouts describing the entire biological continuum of a disease. Such path in Neurology is encouraged by the promising results of omics sciences and SB approaches in Oncology, where stage-driven pathway-based therapies have been developed in line with the precision medicine paradigm. Multi-omics data integrated in SB network approaches will help detect and chart AD upstream pathomechanistic alterations and downstream molecular effects occurring in preclinical stages. Finally, integrating omics and neuroimaging data - i.e., neuroimaging-omics - will identify multi-dimensional biological signatures essential to track the clinical-biological trajectories, at the subpopulation or even individual level.
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19
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Elumalai S, Karunakaran U, Moon JS, Won KC. NADPH Oxidase (NOX) Targeting in Diabetes: A Special Emphasis on Pancreatic β-Cell Dysfunction. Cells 2021; 10:cells10071573. [PMID: 34206537 PMCID: PMC8307876 DOI: 10.3390/cells10071573] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/12/2021] [Accepted: 06/16/2021] [Indexed: 12/24/2022] Open
Abstract
In type 2 diabetes, metabolic stress has a negative impact on pancreatic β-cell function and survival (T2D). Although the pathogenesis of metabolic stress is complex, an imbalance in redox homeostasis causes abnormal tissue damage and β-cell death due to low endogenous antioxidant expression levels in β-cells. Under diabetogenic conditions, the susceptibility of β-cells to oxidative damage by NADPH oxidase has been related to contributing to β-cell dysfunction. Here, we consider recent insights into how the redox response becomes deregulated under diabetic conditions by NADPH oxidase, as well as the therapeutic benefits of NOX inhibitors, which may provide clues for understanding the pathomechanisms and developing strategies aimed at the treatment or prevention of metabolic stress associated with β-cell failure.
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Affiliation(s)
- Suma Elumalai
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea; (S.E.); (U.K.)
| | - Udayakumar Karunakaran
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea; (S.E.); (U.K.)
| | - Jun-Sung Moon
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea; (S.E.); (U.K.)
- Department of Internal Medicine, Yeungnam Universtiy College of Medicine, Daegu 42415, Korea
- Correspondence: (J.-S.M.); (K.-C.W.); Tel.: +82-53-620-3825 (J.-S.W.); +82-53-620-3846 (K.-C.W.)
| | - Kyu-Chang Won
- Innovative Center for Aging Research, Yeungnam University Medical Center, Daegu 42415, Korea; (S.E.); (U.K.)
- Department of Internal Medicine, Yeungnam Universtiy College of Medicine, Daegu 42415, Korea
- Correspondence: (J.-S.M.); (K.-C.W.); Tel.: +82-53-620-3825 (J.-S.W.); +82-53-620-3846 (K.-C.W.)
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20
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Mehmeti I. Mitochondrien im Mittelpunkt der zytokinvermittelten β-Zellzerstörung – Ernst-Friedrich-Pfeiffer-Preis 2020 – eine Kurzübersicht des Preisträgers Ilir Mehmeti. DIABETOL STOFFWECHS 2020. [DOI: 10.1055/a-1247-1283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Ilir Mehmeti
- Dr., Institut für Klinische Biochemie, Medizinische Hochschule Hannover, Hannover
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21
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Oxidative Stress in Cytokine-Induced Dysfunction of the Pancreatic Beta Cell: Known Knowns and Known Unknowns. Metabolites 2020; 10:metabo10120480. [PMID: 33255484 PMCID: PMC7759861 DOI: 10.3390/metabo10120480] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/18/2020] [Accepted: 11/21/2020] [Indexed: 12/12/2022] Open
Abstract
Compelling evidence from earlier studies suggests that the pancreatic beta cell is inherently weak in its antioxidant defense mechanisms to face the burden of protecting itself against the increased intracellular oxidative stress following exposure to proinflammatory cytokines. Recent evidence implicates novel roles for nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Noxs) as contributors to the excessive intracellular oxidative stress and damage under metabolic stress conditions. This review highlights the existing evidence on the regulatory roles of at least three forms of Noxs, namely Nox1, Nox2, and Nox4, in the cascade of events leading to islet beta cell dysfunction, specifically under the duress of chronic exposure to cytokines. Potential crosstalk between key signaling pathways (e.g., inducible nitric oxide synthase [iNOS] and Noxs) in the generation and propagation of reactive molecules and metabolites leading to mitochondrial damage and cell apoptosis is discussed. Available data accrued in investigations involving small-molecule inhibitors and antioxidant protein expression methods as tools toward the prevention of cytokine-induced oxidative damage are reviewed. Lastly, current knowledge gaps in this field, and possible avenues for future research are highlighted.
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22
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Kowluru A. Roles of GTP and Rho GTPases in pancreatic islet beta cell function and dysfunction. Small GTPases 2020; 12:323-335. [PMID: 32867592 DOI: 10.1080/21541248.2020.1815508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A growing body of evidence implicates requisite roles for GTP and its binding proteins (Rho GTPases) in the cascade of events leading to physiological insulin secretion from the islet beta cell. Interestingly, chronic exposure of these cells to hyperglycaemic conditions appears to result in sustained activation of specific Rho GTPases (e.g. Rac1) leading to significant alterations in cellular functions including defects in mitochondrial function and nuclear collapse culminating in beta cell demise. One of the objectives of this review is to highlight our current understanding of the regulatory roles of GTP and Rho GTPases in normal islet function (e.g. proliferation and insulin secretion) as well potential defects in these signalling molecules and metabolic pathways that could contribute islet beta cell dysfunction and loss of functional beta cell mass leading to the onset of diabetes. Potential knowledge gaps in this field and possible avenues for future research are also highlighted. ABBREVIATIONS ARNO: ADP-ribosylation factor nucleotide binding site opener; CML: carboxyl methylation; Epac: exchange protein directly activated by cAMP; ER stress: endoplasmic reticulum stress; FTase: farnesyltransferase; GAP: GTPase activating protein; GDI: GDP dissociation inhibitor; GEF: guanine nucleotide exchange factor; GGTase: geranylgeranyltransferase; GGpp: geranylgeranylpyrophosphate; GGPPS: geranylgeranyl pyrophosphate synthase; GSIS: glucose-stimulated insulin secretion; HGPRTase: hypoxanthine-guanine phosphoribosyltransferase; IMPDH: inosine monophosphate dehydrogenase; α-KIC: α-ketoisocaproic acid; MPA: mycophenolic acid; MVA: mevalonic acid; NDPK: nucleoside diphosphate kinase; NMPK: nucleoside monophosphate kinase; Nox2: phagocyte-like NADPH oxidase; PAK-I: p21-activated kinase-I; β-PIX: β-Pak-interacting exchange factor; PRMT: protein arginine methyltransferase; Rac1: ras-related C3 botulinum toxin substrate 1; Tiam1: T-cell lymphoma invasion and metastasis-inducing protein 1; Trx-1: thioredoxin-1; Vav2: vav guanine nucleotide exchange factor 2.
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Affiliation(s)
- Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center and Department of Pharmaceutical Sciences and Medicine, Wayne State University, Detroit, MI, USA
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23
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Rizzo G. The Antioxidant Role of Soy and Soy Foods in Human Health. Antioxidants (Basel) 2020; 9:antiox9070635. [PMID: 32708394 PMCID: PMC7402135 DOI: 10.3390/antiox9070635] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/08/2020] [Accepted: 07/16/2020] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress seems to play a role in many chronic diseases, such as cardiovascular diseases, diabetes, and some cancers. Research is always looking for effective approaches in the prevention and treatment of these pathologies with safe strategies. Given the central role of nutrition, the identification of beneficial healthy foods can be the best key to having a safe and at the same time effective approach. Soy has always aroused great scientific interest but often this attention is galvanized by the interaction with estrogen receptors and related consequences on health. However, soy, soy foods, and soy bioactive substances seem to have antioxidant properties, suggesting their role in quenching reactive oxygen species, although it was frequently mentioned but not studied in depth. The purpose of this review is to summarize the scientific evidence of the antioxidant properties of soy by identifying the human clinical trials available in the literature. A total of 58 manuscripts were individuated through the literature search for the final synthesis. Soy bioactive substances involved in redox processes appear to be multiple and their use seems promising. Other larger clinical trials with adequate standardization and adequate choice of biomarkers will fill the gap currently existing on the suggestive role of soy in antioxidant mechanisms.
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Affiliation(s)
- Gianluca Rizzo
- Independent Researcher, Via Venezuela 66, 98121 Messina, Italy
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24
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Leguina-Ruzzi A, Vodičková A, Holendová B, Pavluch V, Tauber J, Engstová H, Dlasková A, Ježek P. Glucose-Induced Expression of DAPIT in Pancreatic β-Cells. Biomolecules 2020; 10:biom10071026. [PMID: 32664368 PMCID: PMC7408392 DOI: 10.3390/biom10071026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 12/14/2022] Open
Abstract
Transcript levels for selected ATP synthase membrane FO-subunits-including DAPIT-in INS-1E cells were found to be sensitive to lowering glucose down from 11 mM, in which these cells are routinely cultured. Depending on conditions, the diminished mRNA levels recovered when glucose was restored to 11 mM; or were elevated during further 120 min incubations with 20-mM glucose. Asking whether DAPIT expression may be elevated by hyperglycemia in vivo, we studied mice with hyaluronic acid implants delivering glucose for up to 14 days. Such continuous two-week glucose stimulations in mice increased DAPIT mRNA by >5-fold in isolated pancreatic islets (ATP synthase F1α mRNA by 1.5-fold). In INS-1E cells, the glucose-induced ATP increment vanished with DAPIT silencing (6% of ATP rise), likewise a portion of the mtDNA-copy number increment. With 20 and 11-mM glucose the phosphorylating/non-phosphorylating respiration rate ratio diminished to ~70% and 96%, respectively, upon DAPIT silencing, whereas net GSIS rates accounted for 80% and 90% in USMG5/DAPIT-deficient cells. Consequently, the sufficient DAPIT expression and complete ATP synthase assembly is required for maximum ATP synthesis and mitochondrial biogenesis, but not for insulin secretion as such. Elevated DAPIT expression at high glucose further increases the ATP synthesis efficiency.
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Plecitá-Hlavatá L, Jabůrek M, Holendová B, Tauber J, Pavluch V, Berková Z, Cahová M, Schröder K, Brandes RP, Siemen D, Ježek P. Glucose-Stimulated Insulin Secretion Fundamentally Requires H 2O 2 Signaling by NADPH Oxidase 4. Diabetes 2020; 69:1341-1354. [PMID: 32245800 DOI: 10.2337/db19-1130] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/30/2020] [Indexed: 11/13/2022]
Abstract
NADPH facilitates glucose-stimulated insulin secretion (GSIS) in pancreatic islets (PIs) of β-cells through an as yet unknown mechanism. We found NADPH oxidase isoform 4 (NOX4) to be the main producer of cytosolic H2O2, which is essential for GSIS; an increase in ATP alone was insufficient for GSIS. The fast GSIS phase was absent from PIs from NOX4-null, β-cell-specific knockout mice (NOX4βKO) (though not from NOX2 knockout mice) and from NOX4-silenced or catalase-overexpressing INS-1E cells. Lentiviral NOX4 overexpression or H2O2 rescued GSIS in PIs from NOX4βKO mice. NOX4 silencing suppressed Ca2+ oscillations, and the patch-clamped KATP channel opened more frequently when glucose was high. Mitochondrial H2O2, decreasing upon GSIS, provided alternative redox signaling when 2-oxo-isocaproate or fatty acid oxidation formed superoxides through electron-transfer flavoprotein:Q-oxidoreductase. Unlike GSIS, such insulin secretion was blocked with mitochondrial antioxidant SkQ1. Both NOX4 knockout and NOX4βKO mice exhibited impaired glucose tolerance and peripheral insulin resistance. Thus, the redox signaling previously suggested to cause β-cells to self-check hypothetically induces insulin resistance when it is absent. In conclusion, increases in ATP and H2O2 constitute an essential signal that switches on insulin exocytosis for glucose and branched-chain oxoacids as secretagogues (it does so partially for fatty acids). Redox signaling could be impaired by cytosolic antioxidants; hence, those targeting mitochondria should be preferred for clinical applications to treat (pre)diabetes at any stage.
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Affiliation(s)
- Lydie Plecitá-Hlavatá
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jabůrek
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Blanka Holendová
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Tauber
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Vojtěch Pavluch
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Berková
- Institute of Clinical and Experimental Medicine, Prague, Czech Republic
| | - Monika Cahová
- Institute of Clinical and Experimental Medicine, Prague, Czech Republic
| | - Katrin Schröder
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, Frankfurt, Germany
| | - Ralf P Brandes
- Institut für Kardiovaskuläre Physiologie, Goethe-Universität, Frankfurt, Germany
| | - Detlef Siemen
- Klinik für Neurologie, Universität Magdeburg, Magdeburg, Germany
| | - Petr Ježek
- Department of Mitochondrial Physiology, No. 75, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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26
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Kim HJ, Kim D, Yoon H, Choi CS, Oh YS, Jun HS. Prevention of Oxidative Stress-Induced Pancreatic Beta Cell Damage by Broussonetia Kazinoki Siebold Fruit Extract Via the ERK-Nox4 Pathway. Antioxidants (Basel) 2020; 9:antiox9050406. [PMID: 32397640 PMCID: PMC7278704 DOI: 10.3390/antiox9050406] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023] Open
Abstract
Pancreatic beta cells are vulnerable to oxidative stress, which causes beta cell death and dysfunction in diabetes mellitus. Broussonetia kazinoki Siebold (BK) is a widely used herbal medicine, but its potential effects against beta cell death-induced diabetes have not been studied. Therefore, we investigated the protective effect of an ethanolic extract of BK fruit (BKFE) against streptozotocin (STZ)-induced toxicity in pancreatic beta cells. Intraperitoneal injection of STZ in mice induced hyperglycemia; however, oral administration of BKFE significantly decreased the blood glucose level as well as HbA1c levels. BKFE treatment improved glucose tolerance and increased body weight in diabetic mice. Moreover, BKFE treatment resulted in increased serum insulin levels and insulin expression in the pancreas as well as decreased 4-hydroxynonenal levels induced by oxidative stress. Treatment with STZ decreased cell viability of mouse insulinoma cells (MIN6), which was blocked by BKFE pretreatment. BKFE significantly inhibited apoptotic cells and decreased the expression levels of cleaved-caspase-3 and cleaved-poly (ADP-ribose) polymerase (PARP) induced by STZ treatment. Production of reactive oxygen species in STZ-treated MIN6 cells was also significantly decreased by treatment with BKFE. Erk phosphorylation and Nox4 levels increased in STZ-treated MIN6 cells and the pancreas of mice injected with STZ and this increase was inhibited by treatment with BKFE. Inhibition of Erk phosphorylation by treatment with the PD98059 inhibitor or siRNA Erk also blocked the expression of Nox4 induced by STZ treatment. In conclusion, BKFE inhibits Erk phosphorylation, which in turn prevents STZ-induced oxidative stress and beta cell apoptosis. These results suggested that BKFE can be used to prevent or treat beta cell damage in diabetes.
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Affiliation(s)
- Hyo-Jin Kim
- College of Pharmacy, Gachon University, Incheon 21936, Korea;
| | - Donghee Kim
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea; (D.K.); (H.Y.); (C.S.C.)
| | - Haelim Yoon
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea; (D.K.); (H.Y.); (C.S.C.)
| | - Cheol Soo Choi
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea; (D.K.); (H.Y.); (C.S.C.)
- Department of Medicine, College of Medicine, Gachon University, Incheon 21565, Korea
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea
| | - Yoon Sin Oh
- Department of Food and Nutrition, Eulji University, Seongnam 13135, Korea
- Correspondence: (Y.S.O.); (H.-S.J.); Tel.: +82-31-740-7287 (Y.S.O.); +82-32-899-6056 (H.-S.J.)
| | - Hee-Sook Jun
- College of Pharmacy, Gachon University, Incheon 21936, Korea;
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea; (D.K.); (H.Y.); (C.S.C.)
- Gachon Medical and Convergence Institute, Gachon Gil Medical Center, Incheon 21565, Korea
- Correspondence: (Y.S.O.); (H.-S.J.); Tel.: +82-31-740-7287 (Y.S.O.); +82-32-899-6056 (H.-S.J.)
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Bouzakri K, Veyrat-Durebex C, Holterman C, Arous C, Barbieux C, Bosco D, Altirriba J, Alibashe M, Tournier BB, Gunton JE, Mouche S, Bietiger W, Forterre A, Berney T, Pinget M, Christofori G, Kennedy C, Szanto I. Beta-Cell-Specific Expression of Nicotinamide Adenine Dinucleotide Phosphate Oxidase 5 Aggravates High-Fat Diet-Induced Impairment of Islet Insulin Secretion in Mice. Antioxid Redox Signal 2020; 32:618-635. [PMID: 31931619 DOI: 10.1089/ars.2018.7579] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Aims: Nicotinamide adenine dinucleotide phosphate oxidases (NOX-es) produce reactive oxygen species and modulate β-cell insulin secretion. Islets of type 2 diabetic subjects present elevated expression of NOX5. Here, we sought to characterize regulation of NOX5 expression in human islets in vitro and to uncover the relevance of NOX5 in islet function in vivo using a novel mouse model expressing NOX5 in doxycycline-inducible, β-cell-specific manner (RIP/rtTA/NOX5 mice). Results:In situ hybridization and immunohistochemistry employed on pancreatic sections demonstrated NOX5 messenger ribonucleic acid (mRNA) and protein expressions in human islets. In cultures of dispersed islets, NOX5 protein was observed in somatostatin-positive (δ) cells in basal (2.8 mM glucose) conditions. Small interfering ribonucleic acid (siRNA)-mediated knockdown of NOX5 in human islets cultured in basal glucose concentrations resulted in diminished glucose-induced insulin secretion (GIIS) in vitro. However, when islets were preincubated in high (16.7 mM) glucose media for 12 h, NOX5 appeared also in insulin-positive (β) cells. In vivo, mice with β-cell NOX5 expression developed aggravated impairment of GIIS compared with control mice when challenged with 14 weeks of high-fat diet. Similarly, in vitro palmitate preincubation resulted in more severe reduction of insulin release in islets of RIP/rtTA/NOX5 mice compared with their control littermates. Decreased insulin secretion was most distinct in response to theophylline stimulation, suggesting impaired cyclic adenosine monophosphate (cAMP)-mediated signaling due to increased phosphodiesterase activation. Innovation and Conclusions: Our data provide the first insight into the complex regulation and function of NOX5 in islets implying an important role for NOX5 in δ-cell-mediated intraislet crosstalk in physiological circumstances but also identifying it as an aggravating factor in β-cell failure in diabetic conditions.
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Affiliation(s)
- Karim Bouzakri
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Centre Européen d'Etude du Diabète, Strasbourg, France
| | | | - Chet Holterman
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Caroline Arous
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.,Department of Cellular Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Charlotte Barbieux
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Domenico Bosco
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Jordi Altirriba
- Laboratory of Metabolism, Department of Internal Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Mohamed Alibashe
- Cell Isolation and Transplantation Center, Department of Surgery, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Benjamin B Tournier
- Vulnerability Biomarkers Unit, Division of General Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
| | - Jenny E Gunton
- Centre for Diabetes, Obesity and Endocrinology, Westmead Millennium Institute, The University of Sydney, Sydney, Australia.,Diabetes and Transcription Factors Group, Garvan Institute of Medical Research, Sydney, Australia
| | - Sarah Mouche
- Department of Cellular Physiology and Metabolism, University of Geneva, Geneva, Switzerland.,Department of Internal Medicine, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | | | | | - Thierry Berney
- Division of Transplantation, Department of Surgery, University Hospitals of Geneva, Geneva, Switzerland
| | - Michel Pinget
- Centre Européen d'Etude du Diabète, Strasbourg, France
| | | | - Christopher Kennedy
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Ildiko Szanto
- Department of Internal Medicine, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.,Diabetes Center of the Faculty of Medicine at the University of Geneva, Geneva, Switzerland
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28
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Abstract
Glucose-induced (physiological) insulin secretion from the islet β-cell involves interplay between cationic (i.e., changes in intracellular calcium) and metabolic (i.e., generation of hydrophobic and hydrophilic second messengers) events. A large body of evidence affirms support for novel regulation, by G proteins, of specific intracellular signaling events, including actin cytoskeletal remodeling, transport of insulin-containing granules to the plasma membrane for fusion, and secretion of insulin into the circulation. This article highlights the following aspects of GPCR-G protein biology of the islet. First, it overviews our current understanding of the identity of a wide variety of G protein regulators and their modulatory roles in GPCR-G protein-effector coupling, which is requisite for optimal β-cell function under physiological conditions. Second, it describes evidence in support of novel, noncanonical, GPCR-independent mechanisms of activation of G proteins in the islet. Third, it highlights the evidence indicating that abnormalities in G protein function lead to islet β-cell dysregulation and demise under the duress of metabolic stress and diabetes. Fourth, it summarizes observations of potential beneficial effects of GPCR agonists in preventing/halting metabolic defects in the islet β-cell under various pathological conditions (e.g., metabolic stress and inflammation). Lastly, it identifies knowledge gaps and potential avenues for future research in this evolving field of translational islet biology. Published 2020. Compr Physiol 10:453-490, 2020.
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Affiliation(s)
- Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Center for Translational Research in Diabetes, Biomedical Research Service, John D. Dingell VA Medical Center, Wayne State University, Detroit, Michigan, USA
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29
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Molecular Mechanisms Linking Oxidative Stress and Diabetes Mellitus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8609213. [PMID: 32215179 PMCID: PMC7085395 DOI: 10.1155/2020/8609213] [Citation(s) in RCA: 285] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 12/07/2019] [Accepted: 02/04/2020] [Indexed: 12/15/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disorder characterized by chronic hyperglycemia and an inadequate response to circulatory insulin by peripheral tissues resulting in insulin resistance. Insulin resistance has a complex pathophysiology, and it is contributed to by multiple factors including oxidative stress. Oxidative stress refers to an imbalance between free radical production and the antioxidant system leading to a reduction of peripheral insulin sensitivity and contributing to the development of T2DM via several molecular mechanisms. In this review, we present the molecular mechanisms by which the oxidative milieu contributes to the pathophysiology of insulin resistance and diabetes mellitus.
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30
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Basmaeil Y, Rashid MA, Khatlani T, AlShabibi M, Bahattab E, Abdullah ML, Abomaray F, Kalionis B, Massoudi S, Abumaree M. Preconditioning of Human Decidua Basalis Mesenchymal Stem/Stromal Cells with Glucose Increased Their Engraftment and Anti-diabetic Properties. Tissue Eng Regen Med 2020; 17:209-222. [PMID: 32077075 PMCID: PMC7105536 DOI: 10.1007/s13770-020-00239-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/10/2019] [Accepted: 01/06/2020] [Indexed: 12/19/2022] Open
Abstract
Background: Mesenchymal stem/stromal cells (MSCs) from the decidua basalis (DBMSCs) of the human placenta have important functions that make them potential candidates for cellular therapy. Previously, we showed that DBMSC functions do not change significantly in a high oxidative stress environment, which was induced by hydrogen peroxide (H2O2) and immune cells. Here, we studied the consequences of glucose, another oxidative stress inducer, on the phenotypic and functional changes in DBMSCs. Methods: DBMSCs were exposed to a high level of glucose, and its effect on DBMSC phenotypic and functional properties was determined. DBMSC expression of oxidative stress and immune molecules after exposure to glucose were also identified. Results: Conditioning of DBMSCs with glucose improved their adhesion and invasion. Glucose also increased DBMSC expression of genes with survival, proliferation, migration, invasion, anti-inflammatory, anti-chemoattractant and antimicrobial properties. In addition, DBMSC expression of B7H4, an inhibitor of T cell proliferation was also enhanced by glucose. Interestingly, glucose modulated DBMSC expression of genes involved in insulin secretion and prevention of diabetes. Conclusion: These data show the potentially beneficial effects of glucose on DBMSC functions. Preconditioning of DBMSCs with glucose may therefore be a rational strategy for increasing their therapeutic potential by enhancing their engraftment efficiency. In addition, glucose may program DBMSCs into insulin producing cells with ability to counteract inflammation and infection associated with diabetes. However, future in vitro and in vivo studies are essential to investigate the findings of this study further. Electronic supplementary material The online version of this article (10.1007/s13770-020-00239-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yasser Basmaeil
- Stem Cells and Regenerative Medicine Department, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Mail Code 1515, P.O. Box 22490, Riyadh, 11426, Kingdom of Saudi Arabia.
| | - Manar Al Rashid
- Stem Cells and Regenerative Medicine Department, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Mail Code 1515, P.O. Box 22490, Riyadh, 11426, Kingdom of Saudi Arabia
| | - Tanvir Khatlani
- Stem Cells and Regenerative Medicine Department, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Mail Code 1515, P.O. Box 22490, Riyadh, 11426, Kingdom of Saudi Arabia
| | - Manal AlShabibi
- National Center for Stem Cell Technology, Life Sciences and Environment Research Institute, King Abdulaziz City for Science and Technology, P.O Box 6086, Riyadh, 11442, Kingdom of Saudi Arabia
| | - Eman Bahattab
- National Center for Stem Cell Technology, Life Sciences and Environment Research Institute, King Abdulaziz City for Science and Technology, P.O Box 6086, Riyadh, 11442, Kingdom of Saudi Arabia
| | - Meshan L Abdullah
- Experimental Medicine, King Abdullah International Medical Research Center MNG-HA, Ali Al Arini, Ar Rimayah, Riyadh, 11481, Kingdom of Saudi Arabia
| | - Fawaz Abomaray
- Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, 14186, Stockholm, Sweden
| | - Bill Kalionis
- Department of Maternal-Fetal Medicine, Pregnancy Research Centre and University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Obstetrics and Gynaecology, Royal Women's Hospital, 20 Flemington Rd, Parkville, VIC, 3052, Australia
| | - Safia Massoudi
- Department of Forensic Biology, College of Forensic Sciences, Naif Arab University for Security Sciences, Khurais Rd, Ar Rimayah, Riyadh, 14812, Kingdom of Saudi Arabia
| | - Mohammad Abumaree
- Stem Cells and Regenerative Medicine Department, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Mail Code 1515, P.O. Box 22490, Riyadh, 11426, Kingdom of Saudi Arabia.,College of Science and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Mail Code 3124, P.O. Box 3660, Riyadh, 11481, Kingdom of Saudi Arabia
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31
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Zhang W, Sakoda H, Nakazato M. Neuromedin U suppresses insulin secretion by triggering mitochondrial dysfunction and endoplasmic reticulum stress in pancreatic β-cells. FASEB J 2019; 34:133-147. [PMID: 31914613 DOI: 10.1096/fj.201901743r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/26/2019] [Accepted: 10/09/2019] [Indexed: 12/15/2022]
Abstract
Neuromedin U (NMU), a highly conserved peptide in mammals, is involved in a wide variety of physiological processes. NMU, which is synthesized in β-cells and co-localizes with insulin, directly acts on β-cells via NMU receptor 1 (NMUR1) to suppress glucose-stimulated insulin secretion (GSIS). The mechanism underlying this insulinostatic effect has yet to be elucidated. We observed that NMU caused mitochondrial dysfunction by impairing mitochondrial biogenesis, respiration, and mitochondrial Ca2+ uptake in β-cell-derived MIN6-K8 cells. NMU administration induced the endoplasmic reticulum (ER) stress, as reflected by the activation of ER stress signaling pathways involving ATF6, XBP-1s, and PERK-ATF4-CHOP. Nmu knockdown in MIN6-K8 cells increased the number of insulin granules and improved mitochondrial biogenesis and function. NMU was upregulated in both the islets of db/db mice and palmitate-treated MIN6-K8 cells. Our results highlight the crucial role of NMU in the maintenance of β-cell function and glucose metabolism through regulation of mitochondria dysfunction and ER stress. In pathological stages that develop into diabetes, upregulation of NMU could suppress the insulin secretion by inducing mitochondrial dysfunction and ER stress, which may contribute to subsequent β-cell dysfunction.
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Affiliation(s)
- Weidong Zhang
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Hideyuki Sakoda
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Masamitsu Nakazato
- Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.,AMED-CREST, Agency for Medical Research and Development, Tokyo, Japan
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32
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Ježek P, Jabůrek M, Plecitá-Hlavatá L. Contribution of Oxidative Stress and Impaired Biogenesis of Pancreatic β-Cells to Type 2 Diabetes. Antioxid Redox Signal 2019; 31:722-751. [PMID: 30450940 PMCID: PMC6708273 DOI: 10.1089/ars.2018.7656] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/05/2018] [Indexed: 12/14/2022]
Abstract
Significance: Type 2 diabetes development involves multiple changes in β-cells, related to the oxidative stress and impaired redox signaling, beginning frequently by sustained overfeeding due to the resulting lipotoxicity and glucotoxicity. Uncovering relationships among the dysregulated metabolism, impaired β-cell "well-being," biogenesis, or cross talk with peripheral insulin resistance is required for elucidation of type 2 diabetes etiology. Recent Advances: It has been recognized that the oxidative stress, lipotoxicity, and glucotoxicity cannot be separated from numerous other cell pathology events, such as the attempted compensation of β-cell for the increased insulin demand and dynamics of β-cell biogenesis and its "reversal" at dedifferentiation, that is, from the concomitantly decreasing islet β-cell mass (also due to transdifferentiation) and low-grade islet or systemic inflammation. Critical Issues: At prediabetes, the compensation responses of β-cells, attempting to delay the pathology progression-when exaggerated-set a new state, in which a self-checking redox signaling related to the expression of Ins gene expression is impaired. The resulting altered redox signaling, diminished insulin secretion responses to various secretagogues including glucose, may lead to excretion of cytokines or chemokines by β-cells or excretion of endosomes. They could substantiate putative stress signals to the periphery. Subsequent changes and lasting glucolipotoxicity promote islet inflammatory responses and further pathology spiral. Future Directions: Should bring an understanding of the β-cell self-checking and related redox signaling, including the putative stress signal to periphery. Strategies to cure or prevent type 2 diabetes could be based on the substitution of the "wrong" signal by the "correct" self-checking signal.
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Affiliation(s)
- Petr Ježek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Jabůrek
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Lydie Plecitá-Hlavatá
- Department of Mitochondrial Physiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
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33
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Damacharla D, Thamilselvan V, Zhang X, Mestareehi A, Yi Z, Kowluru A. Quantitative proteomics reveals novel interaction partners of Rac1 in pancreatic β-cells: Evidence for increased interaction with Rac1 under hyperglycemic conditions. Mol Cell Endocrinol 2019; 494:110489. [PMID: 31202817 PMCID: PMC6686664 DOI: 10.1016/j.mce.2019.110489] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/11/2019] [Accepted: 06/11/2019] [Indexed: 11/19/2022]
Abstract
Rac1, a small G protein, regulates physiological insulin secretion from the pancreatic β-cell. Interestingly, Rac1 has also been implicated in the onset of metabolic dysfunction of the β-cell under the duress of hyperglycemia (HG). This study is aimed at the identification of interaction partners of Rac1 in β-cells under basal and HG conditions. Using co-immunoprecipitation and UPLC-ESI-MS/MS, we identified 324 Rac1 interaction partners in INS-1832/13 cells, which represent the largest Rac1 interactome to date. Furthermore, we identified 27 interaction partners that exhibited increased association with Rac1 in β-cells exposed to HG. Western blotting (INS-1832/13 cells, rat islets and human islets) and co-immunoprecipitation (INS-1832/13 cells) further validated the identity of these Rac1 interaction partners including regulators of GPCR-G protein-effector coupling in the islet. These data form the basis for future investigations on contributory roles of these Rac1-specific signaling pathways in islet β-cell function in health and diabetes.
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Affiliation(s)
- Divyasri Damacharla
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA
| | - Vijayalakshmi Thamilselvan
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA
| | - Xiangmin Zhang
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA
| | - Aktham Mestareehi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA
| | - Zhengping Yi
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA
| | - Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, USA; Center for Translational Research in Diabetes, Biomedical Research Service, John D. Dingell VA Medical Center, Detroit, MI, 48201, USA.
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34
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Hedgehog Interacting Protein (Hhip) Regulates Insulin Secretion in Mice Fed High Fat Diets. Sci Rep 2019; 9:11183. [PMID: 31371780 PMCID: PMC6673691 DOI: 10.1038/s41598-019-47633-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/15/2019] [Indexed: 12/15/2022] Open
Abstract
Hedgehog interacting protein (Hhip) is essential for islet formation and beta-cell proliferation during pancreatic development; abnormally elevated Hhip expression has been linked to human pancreatitis. Here, we investigate the role of Hhip in modulating insulin secretion in adult Hhip mice (Hhip +/− vs. Hhip+/+) fed high fat diets (HFD). Both sexes of HFD-Hhip +/+ mice developed impaired glucose intolerance, that was only ameliorated in male HFD-Hhip +/− mice that had high levels of circulating plasma insulin, but not in female HFD-Hhip +/− mice. HFD stimulated Hhip gene expression, mainly in beta cells. Male HFD-Hhip +/+ mice had more large islets in which insulin content was reduced; islet architecture was disordered; and markers of oxidative stress (8-OHdG and Nox 2) were increased. In contrast, male HFD-Hhip +/− mice had more small islets with increased beta cell proliferation, enhanced GSIS, less oxidative stress and preserved islet integrity. In vitro, recombinant Hhip increased Nox2 and NADPH activity and decreased insulin-positive beta cells. siRNA-Hhip increased GSIS and abolished the stimulation of sodium palmitate (PA)-BSA on Nox2 gene expression. We conclude that pancreatic Hhip gene inhibits insulin secretion by altering islet integrity and promoting Nox2 gene expression in beta cells in response to HDF-mediated beta cell dysfunction, a novel finding.
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35
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Herrera-Espejo S, Santos-Zorrozua B, Álvarez-González P, Lopez-Lopez E, Garcia-Orad Á. A Systematic Review of MicroRNA Expression as Biomarker of Late-Onset Alzheimer's Disease. Mol Neurobiol 2019; 56:8376-8391. [PMID: 31240600 DOI: 10.1007/s12035-019-01676-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/09/2019] [Indexed: 12/11/2022]
Abstract
Late-onset Alzheimer's disease (LOAD) is a high-occurrence neurological disorder but the difficulty in identifying precise and early biomarkers has complicated the understanding of the disease and the development of new treatments. In this sense, important knowledge is emerging regarding novel molecular and biological candidates with diagnostic potential, including microRNAs (miRNAs), which have a key role in gene repression. The aim of this systematic review was to define the role of miRNAs' expression as biomarkers for LOAD both in brain tissues, which could help understand the biology of the disease, and circulating tissues, which could serve as non-invasive markers of the pathology. A systematic search was performed in Web of Science and PubMed using the keywords ((Alzheimer or Alzheimer's) and (microRNA or microRNAs or miRNA or miRNAs or miR)) until August 2018 to retrieve all articles that presented independent original data evaluating the impact of miRNA expression on the development of LOAD in human population. A total of 90 studies investigating the role of miRNAs' expression in the development of LOAD were identified. While other widely studied miRNAs such as hsa-miR-146a presented contradictory results among studies, deregulation in brain tissue of seven miRNAs, hsa-miR-16-5p, hsa-miR-34a-5p, hsa-miR-107, hsa-miR-125-5p, hsa-miR-132-3p, hsa-miR-181-3p, and hsa-miR-212-3p, was consistently identified in LOAD patients. Their role in the disease could be mediated through the regulation of key pathways, such as axon guidance, longevity, insulin, and MAPK signaling pathway. However, regarding their role as non-invasive biomarkers of LOAD in fluids, although the limited results available are promising, further studies are required.
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Affiliation(s)
- Soraya Herrera-Espejo
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Medicine and Nursing, University of The Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Borja Santos-Zorrozua
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Medicine and Nursing, University of The Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Paula Álvarez-González
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Medicine and Nursing, University of The Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
| | - Elixabet Lopez-Lopez
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Medicine and Nursing, University of The Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain.
- BioCruces Bizkaia Health Research Institute, Barakaldo, Spain.
| | - África Garcia-Orad
- Department of Genetics, Physical Anthropology and Animal Physiology, Faculty of Medicine and Nursing, University of The Basque Country (UPV/EHU), Barrio Sarriena s/n, 48940, Leioa, Spain
- BioCruces Bizkaia Health Research Institute, Barakaldo, Spain
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36
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Newsholme P, Keane KN, Carlessi R, Cruzat V. Oxidative stress pathways in pancreatic β-cells and insulin-sensitive cells and tissues: importance to cell metabolism, function, and dysfunction. Am J Physiol Cell Physiol 2019; 317:C420-C433. [PMID: 31216193 DOI: 10.1152/ajpcell.00141.2019] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
It is now accepted that nutrient abundance in the blood, especially glucose, leads to the generation of reactive oxygen species (ROS), ultimately leading to increased oxidative stress in a variety of tissues. In the absence of an appropriate compensatory response from antioxidant mechanisms, the cell, or indeed the tissue, becomes overwhelmed by oxidative stress, leading to the activation of intracellular stress-associated pathways. Activation of the same or similar pathways also appears to play a role in mediating insulin resistance, impaired insulin secretion, and late diabetic complications. The ability of antioxidants to protect against the oxidative stress induced by hyperglycemia and elevated free fatty acid (FFA) levels in vitro suggests a causative role of oxidative stress in mediating the latter clinical conditions. In this review, we describe common biochemical processes associated with oxidative stress driven by hyperglycemia and/or elevated FFA and the resulting clinical outcomes: β-cell dysfunction and peripheral tissue insulin resistance.
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Affiliation(s)
- Philip Newsholme
- School of Pharmacy and Biomedical Sciences, and Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia
| | - Kevin N Keane
- School of Pharmacy and Biomedical Sciences, and Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia
| | - Rodrigo Carlessi
- School of Pharmacy and Biomedical Sciences, and Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia
| | - Vinicius Cruzat
- Faculty of Health, Torrens University Australia, Melbourne, Victoria, Australia
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37
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Wang X, Gao YT, Jiang D, Wang Y, Du H, Lv J, Li SJ. Hv1-deficiency protects β cells from glucotoxicity through regulation of NOX4 level. Biochem Biophys Res Commun 2019; 513:434-438. [PMID: 30967259 DOI: 10.1016/j.bbrc.2019.03.195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 03/29/2019] [Indexed: 11/27/2022]
Abstract
High glucose (HG)-induced oxidative stress contributes to the dysfunction of pancreatic β cells in diabetes. The voltage-gated proton channel Hv1 has been proposed to support reactive oxygen species (ROS) production during respiratory bursts. However, the effect of Hv1 on glucotoxicity in pancreatic β cells is not clear yet. In this study, we examined the protective effects of Hv1-deficiency in HG cultured β cells. Following 48 h of treatment with 30 mM high glucose, Hv1 KO β cells showed higher cell viability, lower cell apoptosis and a more stable insulin gene expression level compared to WT β cells. In both control and HG cultured β cells, deficiency of Hv1 decreased the glucose- and PMA-induced ROS production. Finally, HG incubation led to NOX4 upregulation in WT β cells, which could be inhibited by HV1 deficiency. In conclusion, Hv1-deficiency prevents the HG treatment-induced NOX4 upregulation and protects β cells from glucotoxicity.
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Affiliation(s)
- Xudong Wang
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Ying-Tang Gao
- Key Laboratory of Artificial Cell, Third Central Clinical College of Tianjin Medical University, Tianjin, 300170, PR China
| | - Dan Jiang
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Yuzhou Wang
- Laboratory Animal Center, College of Life Sciences, Nankai University, Tianjin, 300071, PR China
| | - Hongyan Du
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Jili Lv
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Shu Jie Li
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China.
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Tang R, Liu H. Identification of Temporal Characteristic Networks of Peripheral Blood Changes in Alzheimer's Disease Based on Weighted Gene Co-expression Network Analysis. Front Aging Neurosci 2019; 11:83. [PMID: 31178714 PMCID: PMC6537635 DOI: 10.3389/fnagi.2019.00083] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/25/2019] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disease. The study of blood-based biomarkers has lasted for a long time in AD, because it supports the concept that peripheral changes are involved in AD pathology. But it is still unclear how peripheral blood is involved in the temporal characteristic molecular mechanisms of AD from aging to mild cognitive impairment (MCI) and which cells are responsible for the molecular mechanisms. The main purpose of our study is to gain a systematic and comprehensive understanding of temporal characteristic networks of peripheral blood in AD using whole blood samples with 329 case-control samples, including 104 normal elderly control subjects (CTL), 80 MCI who are susceptible to AD, and 145 AD, by the weighted gene co-expression network analysis (WGCNA). The module-trait relationships were constructed and module preservation was validated with independent datasets GSE63061, GSE97760, GSE18309, GSE29378, GSE28146, and GSE29652. Our results indicate that the down-regulated protein modification and ubiquitin degradation systems, and the up-regulated insulin resistance both play a major role in MCI, while the up-regulated inflammatory cascade dominates in AD, which is mainly mediated by monocytes, macrophages. Although there is mixed activation of M1 and M2 macrophages in all stages of AD, the immune neutral state or M2 polarization may predominate in MCI, and M1 polarization may predominate in AD. Moreover, we found that TRPV2, NDUFV1, ATF4, HSPA8, STAT3 and LUC7L3 may mediate the pathological changes in MCI, while SIRPA, LAMP-2, NDUFB5, HSPA8, STAT3 and FPR2 may mediate the conversion from MCI-AD or the pathological changes in AD, which provide a basis for the treatment based on the peripheral blood system. In addition, we also found that the combined diagnosis based on a panel of genes from the red, blue, and brown modules have a moderate diagnostic effect on distinguishing MCI and AD from CTL, suggesting that those panels of genes may be used for detection of MCI and prediction of this conversion from MCI to AD. Our research emphasizes that pathological changes, based on temporal characteristics of peripheral blood, provide a theoretical basis for targeted peripheral treatment based on appropriate times and identified several diagnostic markers.
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Affiliation(s)
- Runhong Tang
- Department of Neurology, First Affiliated Hospital, China Medical University, Shenyang, China
| | - Huayan Liu
- Department of Neurology, First Affiliated Hospital, China Medical University, Shenyang, China
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Ding M, Fang QH, Cui YT, Shen QL, Liu Q, Wang PH, Yu DM, Li CJ. Liraglutide prevents β-cell apoptosis via inactivation of NOX2 and its related signaling pathway. J Diabetes Complications 2019; 33:267-277. [PMID: 30772113 DOI: 10.1016/j.jdiacomp.2018.12.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 11/20/2018] [Accepted: 12/26/2018] [Indexed: 01/01/2023]
Abstract
AIMS High glucose (HG)-induced pancreatic β-cell apoptosis may be a major contributor to the progression of diabetes mellitus (DM). NADPH oxidase (NOX2) has been considered a crucial regulator in β-cell apoptosis. This study was designed to evaluate the impact of GLP-1 receptor agonist (GLP-1Ra) liraglutide on pancreatic β-cell apoptosis in diabetes and the underlying mechanisms involved. METHODS The diabetic rat models induced by streptozotocin (STZ) and a high fat diet (HFD) received 12 weeks of liraglutide treatment. Hyperglycemic clamp test was carried out to evaluate β-cell function in vivo. Flow cytometry analysis was used to measure apoptosis rates in vitro. DCFH-DA method was used to detected ROS level in vivo and in vitro. RESULTS Liraglutide significantly improved islet function and morphology in diabetic rats and decreased cell apoptosis rates. Thr183/Thr185 p-JNK1/2 and NOX2 levels reduced in diabetic rats and HG-induced INS-1 cell following liraglutide treatment. In addition, liraglutide upregulated the phosphorylation of AMPKα (p-AMPKα), which prevented NOX2 activation and alleviated HG-induced β-cell apoptosis. CONCLUSION The p-AMPKα/NOX2/JNK1/2 pathway is essential for liraglutide to attenuate HG-induced β-cell apoptosis, which further proves that GLP-1Ras may become promising therapeutics for diabetes mellitus.
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Affiliation(s)
- Min Ding
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qian-Hua Fang
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Yuan-Tao Cui
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qi-Ling Shen
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Qian Liu
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - Peng-Hua Wang
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China
| | - De-Min Yu
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China.
| | - Chun-Jun Li
- NHC Key Laboratory of Hormones and Development (Tianjin Medical University), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin 300070, PR China.
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Previte DM, Piganelli JD. Reactive Oxygen Species and Their Implications on CD4 + T Cells in Type 1 Diabetes. Antioxid Redox Signal 2018; 29:1399-1414. [PMID: 28990401 DOI: 10.1089/ars.2017.7357] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Previous work has indicated that type 1 diabetes (T1D) pathology is highly driven by reactive oxygen species (ROS). One way in which ROS shape the autoimmune response demonstrated in T1D is by promoting CD4+ T cell activation and differentiation. As CD4+ T cells are a significant contributor to pancreatic β cell destruction in T1D, understanding how ROS impact their development, activation, and differentiation is critical. Recent Advances: CD4+ T cells themselves generate ROS via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression and electron transport chain activity. Moreover, T cells can also be exposed to exogenous ROS generated by other immune cells (e.g., macrophages and dendritic cells) and β cells. Genetically modified animals and ROS inhibitors have demonstrated that ROS blockade during activation results in CD4+ T cell hyporesponsiveness and reduced diabetes incidence. Critical Issues and Future Directions: Although the majority of studies with regard to T1D and CD4+ T cells have been done to examine the influence of redox on CD4+ T cell activation, this is not the only circumstance in which a T cell can be impacted by redox. ROS and redox have also been shown to play roles in CD4+ T cell-related tolerogenic mechanisms, including thymic selection and regulatory T cell-mediated suppression. However, the effect of these mechanisms with respect to T1D pathogenesis remains elusive. Therefore, pursuing these avenues may provide valuable insight into the global role of ROS and redox in autoreactive CD4+ T cell formation and function.
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Affiliation(s)
- Dana M Previte
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center , Pittsburgh, Pennsylvania
| | - Jon D Piganelli
- Department of Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center , Pittsburgh, Pennsylvania
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Jeong JH, Koo JH, Cho JY, Kang EB. Neuroprotective effect of treadmill exercise against blunted brain insulin signaling, NADPH oxidase, and Tau hyperphosphorylation in rats fed a high-fat diet. Brain Res Bull 2018; 142:374-383. [DOI: 10.1016/j.brainresbull.2018.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/08/2018] [Accepted: 08/01/2018] [Indexed: 11/24/2022]
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Barlow J, Solomon TPJ, Affourtit C. Pro-inflammatory cytokines attenuate glucose-stimulated insulin secretion from INS-1E insulinoma cells by restricting mitochondrial pyruvate oxidation capacity - Novel mechanistic insight from real-time analysis of oxidative phosphorylation. PLoS One 2018; 13:e0199505. [PMID: 29953508 PMCID: PMC6023166 DOI: 10.1371/journal.pone.0199505] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/10/2018] [Indexed: 11/30/2022] Open
Abstract
Pro-inflammatory cytokines cause pancreatic beta cell failure during the development of type 2 diabetes. This beta cell failure associates with mitochondrial dysfunction, but the precise effects of cytokines on mitochondrial respiration remain unclear. To test the hypothesis that pro-inflammatory cytokines impair glucose-stimulated insulin secretion (GSIS) by inhibiting oxidative ATP synthesis, we probed insulin release and real-time mitochondrial respiration in rat INS-1E insulinoma cells that were exposed to a combination of 2 ng/mL interleukin-1-beta and 50 ng/mL interferon-gamma. We show that 24-h exposure to these cytokines dampens both glucose- and pyruvate-stimulated insulin secretion (P < 0.0001 and P < 0.05, respectively), but does not affect KCl-induced insulin release. Mirroring secretory defects, glucose- and pyruvate-stimulated mitochondrial respiration are lowered after cytokine exposure (P < 0.01). Further analysis confirms that cytokine-induced mitochondrial respiratory defects occur irrespective of whether fuel oxidation is coupled to, or uncoupled from, ATP synthesis. These observations demonstrate that pro-inflammatory cytokines attenuate GSIS by restricting mitochondrial pyruvate oxidation capacity. Interleukin-1-beta and interferon-gamma also increase mitochondrial superoxide levels (P < 0.05), which may reinforce the inhibition of pyruvate oxidation, and cause a modest (20%) but significant (P < 0.01) loss of INS-1E cells. Cytokine-induced INS-1E cell failure is insensitive to palmitoleate and linoleate, which is at odds with the cytoprotection offered by unsaturated fatty acids against harm caused by nutrient excess. Our data disclose a mitochondrial mechanism for cytokine-impaired GSIS in INS-1E cells, and suggest that inflammatory and nutrient-related beta cell failure emerge, at least partly, through distinct paths.
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Affiliation(s)
- Jonathan Barlow
- School of Biomedical and Healthcare Sciences, University of Plymouth, Plymouth, United Kingdom
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Thomas P. J. Solomon
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
- Institute for Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, United Kingdom
| | - Charles Affourtit
- School of Biomedical and Healthcare Sciences, University of Plymouth, Plymouth, United Kingdom
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Alshehri AM, Mendis T, Jackson MW. A cell-based assay for the detection of pathogenic anti-voltage-gated calcium channel autoantibodies in immunoglobulin G from patients with type 1 diabetes. J Immunol Methods 2018; 460:79-86. [PMID: 29940155 DOI: 10.1016/j.jim.2018.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/30/2018] [Accepted: 06/19/2018] [Indexed: 10/28/2022]
Abstract
Recent studies have postulated the presence of functional autoantibodies (Abs) against L-type voltage gated calcium channels (VGCCs) in the serum of patients with type 1 diabetes, with various proposed physiological consequences, both islet cell associated and extra-glandular. Arguably, the most potentially damaging effect reported for these Abs is induction of apoptosis in pancreatic beta (β) cells, yet a convincing pathogenic mechanism remains to be demonstrated. In the current study, we report an assay of reactive oxygen species (ROS) stress induction in the rat insulinoma cell line Rin A12, as determined by 2', 7'-Dichlorofluorescein diacetate (DCF-DA) fluorescence detection by flow cytometry. We demonstrate that incubation of Rin A12 cells with immunoglobulin G (IgG) containing anti-VGCC activity from patients with T1D mediates a significant increase in ROS, with subsequent induction of apoptosis, as determined by positivity for annexin V expression. Neither T1D patient-derived IgG lacking anti-VGCC activity or IgG from healthy donors altered ROS or annexin V expression, indicating the new assay is specific for the detection of functional anti-VGCC Abs. Subsequent screening of IgG samples derived from individual patients indicated a prevalence of approximately 75% in a cohort of 20 patients with T1D. The new cell-based assay provides, for the first time, experimental evidence supporting a plausible pathophysiological mechanism underlying anti-VGCC Ab-mediated apoptosis induction in β cells. Additionally, the assay is a considerable advance on previously published methods for detecting and characterising the functional activity of anti-VGCC Abs in patient-derived samples.
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Affiliation(s)
- Ahmed M Alshehri
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia
| | - Thilini Mendis
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia
| | - Michael W Jackson
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia.
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Baidwan S, Chekuri A, Hynds DL, Kowluru A. Glucotoxicity promotes aberrant activation and mislocalization of Ras-related C3 botulinum toxin substrate 1 [Rac1] and metabolic dysfunction in pancreatic islet β-cells: reversal of such metabolic defects by metformin. Apoptosis 2018; 22:1380-1393. [PMID: 28828705 DOI: 10.1007/s10495-017-1409-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence suggests that long-term exposure of insulin-secreting pancreatic β-cells to hyperglycemic (HG; glucotoxic) conditions promotes oxidative stress, which, in turn, leads to stress kinase activation, mitochondrial dysfunction, loss of nuclear structure and integrity and cell apoptosis. Original observations from our laboratory have proposed that Rac1 plays a key regulatory role in the generation of oxidative stress and downstream signaling events culminating in the onset of dysfunction of pancreatic β-cells under the duress of metabolic stress. However, precise molecular and cellular mechanisms underlying the metabolic roles of hyperactive Rac1 remain less understood. Using pharmacological and molecular biological approaches, we now report mistargetting of biologically-active Rac1 [GTP-bound conformation] to the nuclear compartment in clonal INS-1 cells, normal rat islets and human islets under HG conditions. Our findings also suggest that such a signaling step is independent of post-translational prenylation of Rac1. Evidence is also presented to highlight novel roles for sustained activation of Rac1 in HG-induced expression of Cluster of Differentiation 36 [CD36], a fatty acid transporter protein, which is implicated in cell apoptosis. Finally, our findings suggest that metformin, a biguanide anti-diabetic drug, at a clinically relevant concentration, prevents β-cell defects [Rac1 activation, nuclear association, CD36 expression, stress kinase and caspase-3 activation, and loss in metabolic viability] under the duress of glucotoxicity. Potential implications of these findings in the context of novel and direct regulation of islet β-cell function by metformin are discussed.
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Affiliation(s)
- Sartaj Baidwan
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, Detroit, MI, USA.,Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA
| | - Anil Chekuri
- Shiley Eye Institute, University of California, La Jolla, CA, 92093, USA
| | - DiAnna L Hynds
- Department of Biology, Texas Woman's University, Denton, TX, 76204, USA
| | - Anjaneyulu Kowluru
- β-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, Detroit, MI, USA. .,Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA. .,B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R Street, Detroit, MI, 48201, USA.
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Lee J, Ma K, Moulik M, Yechoor V. Untimely oxidative stress in β-cells leads to diabetes - Role of circadian clock in β-cell function. Free Radic Biol Med 2018; 119:69-74. [PMID: 29458148 PMCID: PMC5910243 DOI: 10.1016/j.freeradbiomed.2018.02.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 02/12/2018] [Accepted: 02/14/2018] [Indexed: 12/31/2022]
Abstract
Diabetes results from a loss of β-cell function. With the number of people with diabetes reaching epidemic proportions globally, understanding mechanisms that are contributing to this increasing prevalence is critical. One such factor has been circadian disruption, with shift-work, light pollution, jet-lag, increased screen time, all acting as potential contributory factors. Though circadian disruption has been epidemiologically associated with diabetes and other metabolic disorders for many decades, it is only recently that there has been a better understanding of the underlying molecular mechanisms. Experimental circadian disruption, via manipulation of environmental or genetic factors using gene-deletion mouse models, has demonstrated the importance of circadian rhythms in whole body metabolism. Genetic disruption of core clock genes, specifically in the β-cells in mice, have, now demonstrated the importance of the intrinsic β-cell clock in regulating function. Recent work has also shown the interaction of the circadian clock and enhancers in β-cells, indicating a highly integrated regulation of transcription and cellular function by the circadian clock. Disruption of either the whole body or only the β-cell clock leads to significant impairment of mitochondrial function, uncoupling, impaired vesicular transport, oxidative stress in β-cells and finally impaired glucose-stimulated insulin secretion and diabetes. In this review, we explore the role of the circadian clock in mitigating oxidative stress and preserving β-cell function.
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Affiliation(s)
- J Lee
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, University of Pittsburgh, 200 Lothrop, BST-1058W, Pittsburgh, PA 15261, United States
| | - K Ma
- Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, United States
| | - M Moulik
- Division of Cardiology, Department of Pediatrics, Children's Hospital of Pittsburgh and University of Pittsburgh, Pittsburgh, PA, United States
| | - V Yechoor
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes & Metabolism, Department of Medicine, University of Pittsburgh, 200 Lothrop, BST-1058W, Pittsburgh, PA 15261, United States.
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Kowluru A, Kowluru RA. RACking up ceramide-induced islet β-cell dysfunction. Biochem Pharmacol 2018; 154:161-169. [PMID: 29715450 DOI: 10.1016/j.bcp.2018.04.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Abstract
The International Diabetes Federation predicts that by 2045 the number of individuals afflicted with diabetes will increase to 629 million. Furthermore, ∼352 million individuals with impaired glucose tolerance are at increased risk for developing diabetes. Several mechanisms have been proposed for the onset of metabolic dysfunction and demise of the islet β-cell leading to the pathogenesis of diabetes. It is widely accepted that the onset of type 2 diabetes is due to an intricate interplay between genetic expression of the disease and a multitude of factors including increased oxidative and endoplasmic reticulum stress consequential to glucolipotoxicity and inflammation. Compelling experimental evidence from in vitro and in vivo studies implicates intracellular generation of ceramide (CER), a biologically-active sphingolipid, as a trigger in the onset of β-cell demise under above pathological conditions. Recent pharmacological and molecular biological evidence affirms regulatory roles for Ras-related C3 botulinum toxin substrate 1 (Rac1), a small G protein, in the islet β-cell function in health and diabetes. In this Commentary, we overviewed the emerging evidence implicating potential cross-talk between Rac1 and ceramide signaling pathways in the onset of metabolic dysregulation of the islet β-cell culminating in impaired physiological insulin secretion, loss of β-cell mass and the onset of diabetes. Further, we propose a model depicting contributory roles of defective protein lipidation (prenylation) pathway in the induction of metabolic defects in the β-cell under metabolic stress conditions. Potential avenues for the identification of novel therapeutic targets for the prevention/treatment of diabetes and its associated complications are highlighted.
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Affiliation(s)
- Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center, Wayne State University, Detroit, MI 48201, USA; Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201, USA.
| | - Renu A Kowluru
- Department of Ophthalmology and Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, USA
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Singh S, Bhowmick DC, Pany S, Joe M, Zaghlula N, Jeremic AM. Apoptosis signal regulating kinase-1 and NADPH oxidase mediate human amylin evoked redox stress and apoptosis in pancreatic beta-cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1721-1733. [PMID: 29627323 DOI: 10.1016/j.bbamem.2018.03.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 01/20/2023]
Abstract
Misfolded toxic human islet amyloid polypeptide or amylin (hA) and plasma membrane-associated redox complex, NADPH oxidase (NOX), have been implicated in the islet β-cell demise associated with type-2 diabetes mellitus (T2DM). Studies show that hA accumulation is stressful to β-cells and that misfolding of human amylin evokes redox stress and activates mitogen activated protein (MAP) kinases, p38 MAPK and c-Jun N-terminal (JNK) kinase. However, the molecular link and causality between hA-evoked redox stress, NOX activity and MAP kinases signaling in pancreatic β-cells is incompletely understood. Here, we show that in the process of activating JNK, aggregation prone hA also activates an upstream apoptosis signal regulating kinase-1 (ASK1) with concomitant decrease in intracellular levels of reduced glutathione. Inhibition of ASK1 kinase activity, either by specific ASK1 inhibitor, NQDI1 or by thiol antioxidants reduces human amylin-evoked ASK1 and JNK activation and consequently human amylin toxicity in rat insulinoma Rin-m5F cells and human islets. β-cell specific overexpression of human amylin in mouse islets elicited ASK1 phosphorylation and activation in β-cells but not in other rodent's islet or exocrine cells. This ASK1 activation strongly correlated with islet amyloidosis and diabetes progression. Cytotoxic human amylin additionally stimulated pro-oxidative activity and expressions of plasma membrane bound NADPH oxidase (NOX) and its regulatory subunits. siRNA mediated NOX1 knockdown and selective NOX inhibitors, ML171 and apocynin, significantly reduced hA-induced mitochondrial stress in insulinoma beta-cells. However, NOX inhibitors were largely ineffective against hA-evoked redox stress and activation of cytotoxic ASK1/JNK signaling complex. Thus, our studies suggest that NOX1 and ASK1 autonomously mediate human amylin-evoked redox and mitochondrial stress in pancreatic β-cells.
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Affiliation(s)
- Sanghamitra Singh
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | | | - Satyabrata Pany
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Myungkuk Joe
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Noor Zaghlula
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Aleksandar M Jeremic
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA.
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Wang X, Xi W, Qin J, Lv J, Wang Y, Zhang T, Li SJ. Deficiency of voltage-gated proton channel Hv1 attenuates streptozotocin-induced β-cell damage. Biochem Biophys Res Commun 2018; 498:975-980. [DOI: 10.1016/j.bbrc.2018.03.092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 03/13/2018] [Indexed: 10/17/2022]
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49
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Sidarala V, Kowluru A. Exposure to chronic hyperglycemic conditions results in Ras-related C3 botulinum toxin substrate 1 (Rac1)-mediated activation of p53 and ATM kinase in pancreatic β-cells. Apoptosis 2018; 22:597-607. [PMID: 28220272 DOI: 10.1007/s10495-017-1354-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Chronic hyperglycemia (HG) promotes pancreatic islet dysfunction which leads to the onset of T2DM. This study is aimed at defining regulatory roles of Rac1, a small G-protein, in the activation of p53 and ATM kinase in pancreatic β-cells, under the duress of HG conditions. We report significant stimulatory effects of HG (20 mM; 24 h) on p53 activation in INS-1 832/13 cells, normal rodent and human islets. Pharmacological inhibition of Rac1 (EHT1864 or NSC23766) significantly suppressed HG-induced p53 activation in INS-1 832/13 cells and rat islets, suggesting novel roles for this small G-protein in the activation of p53. Inhibition of Rac1 geranylgeranylation with simvastatin or GGTI-2147, significantly attenuated HG-induced p53 activation, suggesting requisite roles for this signaling step in HG-mediated effects on β-cells. HG-induced p53 activation was also suppressed by SB203580, a known inhibitor of p38MAPK. Additionally, we observed increased activation of ATM kinase under HG conditions, which was blocked in presence of EHT1864. Furthermore, pharmacological inhibition of ATM kinase (KU55933) reduced activation of ATM kinase, but not p53, suggesting that HG-mediated activation of p53 and ATM could represent independent pro-apoptotic events. In conclusion, these data indicate that sustained activation of Rac1-p38MAPK signaling axis leads to activation of p53 leading to β-cell dysfunction under the duress of chronic hyperglycemic conditions.
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Affiliation(s)
- Vaibhav Sidarala
- Beta-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, B-4237 Research Service, 4646 John R, Detroit, MI, 48201, USA.,Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA.,Division of Metabolism, Endocrinology and Diabetes (MEND), Department of Internal Medicine, Brehm Diabetes Research Center, University of Michigan Medical School, Ann Arbor, MI, 48105-1912, USA
| | - Anjaneyulu Kowluru
- Beta-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, B-4237 Research Service, 4646 John R, Detroit, MI, 48201, USA. .,Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI, 48201, USA.
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50
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Sidarala V, Kowluru A. The Regulatory Roles of Mitogen-Activated Protein Kinase (MAPK) Pathways in Health and Diabetes: Lessons Learned from the Pancreatic β-Cell. ACTA ACUST UNITED AC 2017; 10:76-84. [PMID: 27779078 DOI: 10.2174/1872214810666161020154905] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/17/2016] [Accepted: 10/17/2016] [Indexed: 01/14/2023]
Abstract
BACKGROUND Glucose-stimulated insulin secretion (GSIS) from the pancreatic β-cell involves several intracellular metabolic events which lead to the translocation of insulin granules towards the membrane for fusion and release. It is well established that loss of β-cell function and decreased GSIS underlie the pathogenesis of diabetes. Evidence from several laboratories, including our own, demonstrated requisite roles of Rac1 and phagocyte-like NADPH oxidase (Nox2)-derived reactive oxygen species (ROS) in optimal function of the pancreatic β-cell, including GSIS. However, it is becoming increasingly clear that prolonged exposure of β-cells to hyperglycemic conditions, leads to sustained activation of Rac1-Nox2 signaling axis culminating in excessive generation of intracellular ROS (oxidative stress) and β-cell dysregulation and demise. Such "cytotoxic" effects of ROS appear to be mediated via the stress-activated protein kinases/mitogen-activated protein kinases (SAPK/MAPK) signaling pathways. OBJECTIVE This review discusses our current understanding of regulation and functions of the conventional MAPKs, namely, ERK1/2, JNK1/2 and p38MAPK. CONCLUSION The MAPK pathways are activated in the presence of various stress stimuli including intracellular ROS, via distinct signaling cascades. Once activated, MAPKs participate in specific intracellular signaling processes via interaction with several downstream kinases including the MAPKactivated protein kinases (MAPKAPKs) and transcription factors including c-jun and p53. We have provided an overview of existing evidence in the islet β-cell on the regulatory roles of these MAPKs in mediating cellular responses to alterations in intracellularly generated ROS, which is mediated by the Rac1-Nox2 signaling module. Additionally, we enlisted recent patents developed to improve β-cell function in diabetes and novel pharmacological agents that target oxidative stress and MAPK pathways.
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Affiliation(s)
- Vaibhav Sidarala
- Beta-Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48201. United States
| | - Anjaneyulu Kowluru
- B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI 48201. United States
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