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Hall LG, Thyfault JP, Johnson JD. Exercise and inactivity as modifiers of β cell function and type 2 diabetes risk. J Appl Physiol (1985) 2023; 134:823-839. [PMID: 36759159 PMCID: PMC10042613 DOI: 10.1152/japplphysiol.00472.2022] [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: 08/15/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 02/11/2023] Open
Abstract
Exercise and regular physical activity are beneficial for the prevention and management of metabolic diseases such as obesity and type 2 diabetes, whereas exercise cessation, defined as deconditioning from regular exercise or physical activity that has lasted for a period of months to years, can lead to metabolic derangements that drive disease. Adaptations to the insulin-secreting pancreatic β-cells are an important benefit of exercise, whereas less is known about how exercise cessation affects these cells. Our aim is to review the impact that exercise and exercise cessation have on β-cell function, with a focus on the evidence from studies examining glucose-stimulated insulin secretion (GSIS) using gold-standard techniques. Potential mechanisms by which the β-cell adapts to exercise, including exerkine and incretin signaling, autonomic nervous system signaling, and changes in insulin clearance, will also be explored. We will highlight areas for future research.
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Affiliation(s)
- Liam G Hall
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - John P Thyfault
- Department of Cell Biology and Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States
- KU Diabetes Institute, University of Kansas Medical Center, Kansas City, Kansas, United States
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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2
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Cen HH, Hussein B, Botezelli JD, Wang S, Zhang JA, Noursadeghi N, Jessen N, Rodrigues B, Timmons JA, Johnson JD. Human and mouse muscle transcriptomic analyses identify insulin receptor mRNA downregulation in hyperinsulinemia-associated insulin resistance. FASEB J 2022; 36:e22088. [PMID: 34921686 PMCID: PMC9255858 DOI: 10.1096/fj.202100497rr] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Hyperinsulinemia is commonly viewed as a compensatory response to insulin resistance, yet studies have demonstrated that chronically elevated insulin may also drive insulin resistance. The molecular mechanisms underpinning this potentially cyclic process remain poorly defined, especially on a transcriptome-wide level. Transcriptomic meta-analysis in >450 human samples demonstrated that fasting insulin reliably and negatively correlated with INSR mRNA in skeletal muscle. To establish causality and study the direct effects of prolonged exposure to excess insulin in muscle cells, we incubated C2C12 myotubes with elevated insulin for 16 h, followed by 6 h of serum starvation, and established that acute AKT and ERK signaling were attenuated in this model of in vitro hyperinsulinemia. Global RNA-sequencing of cells both before and after nutrient withdrawal highlighted genes in the insulin receptor (INSR) signaling, FOXO signaling, and glucose metabolism pathways indicative of 'hyperinsulinemia' and 'starvation' programs. Consistently, we observed that hyperinsulinemia led to a substantial reduction in Insr gene expression, and subsequently a reduced surface INSR and total INSR protein, both in vitro and in vivo. Bioinformatic modeling combined with RNAi identified SIN3A as a negative regulator of Insr mRNA (and JUND, MAX, and MXI as positive regulators of Irs2 mRNA). Together, our analysis identifies mechanisms which may explain the cyclic processes underlying hyperinsulinemia-induced insulin resistance in muscle, a process directly relevant to the etiology and disease progression of type 2 diabetes.
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Affiliation(s)
- Haoning Howard Cen
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bahira Hussein
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - José Diego Botezelli
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Su Wang
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jiashuo Aaron Zhang
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nilou Noursadeghi
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Niels Jessen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Brian Rodrigues
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - James A Timmons
- Augur Precision Medicine LTD, Stirling University Innovation Park, Stirling, Scotland.,William Harvey Research Institute, Queen Mary University of London, London, UK
| | - James D Johnson
- Department of Cellular and Physiological Sciences, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada
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3
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Characteristics of the New Insulin-Resistant Zebrafish Model. Pharmaceuticals (Basel) 2021; 14:ph14070642. [PMID: 34358068 PMCID: PMC8308799 DOI: 10.3390/ph14070642] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 01/09/2023] Open
Abstract
Insulin resistance, which occurs when insulin levels are sufficiently high over a prolonged period, causing the cells to fail to respond normally to the hormone. As a system for insulin resistance and diabetes drug development, insulin-resistant rodent models have been clearly established, but there is a limitation to high-throughput drug screening. Recently, zebrafish have been identified as an excellent system for drug discovery and identification of therapeutic targets, but studies on insulin resistance models have not been extensively performed. Therefore, we aimed to make a rapid insulin-resistant zebrafish model that complements the existing rodent models. To establish this model, zebrafish were treated with 10 μM insulin for 48 h. This model showed characteristics of insulin-resistant disease such as damaged pancreatic islets. Then we confirmed the recovery of the pancreatic islets after pioglitazone treatment. In addition, it was found that insulin-resistant drugs have as significant an effect in zebrafish as in humans, and these results proved the value of the zebrafish insulin resistance model for drug selection. In addition, RNA sequencing was performed to elucidate the mechanism involved. KEGG pathway enrichment analysis of differentially expressed genes showed that insulin resistance altered gene expression due to the MAPK signaling and calcium signaling pathways. This model demonstrates the utility of the zebrafish model for drug testing and drug discovery in insulin resistance and diabetes.
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Abstract
CONTEXT Obesity and type 2 diabetes are associated with chronic hyperinsulinemia, elevated plasma levels of dipeptidyl peptidase-4 (DPP4), and a pro-atherosclerotic milieu. EVIDENCE ACQUISITION PubMed search of the term "insulin and atherosclerosis," "hyperinsulinemia," "atherosclerosis," or "cardiovascular outcomes" cross-referenced with "DPP4." Relevant research and review articles were reviewed. EVIDENCE SYNTHESIS Hyperinsulinemia in the setting of insulin resistance promotes vascular inflammation, vascular smooth muscle cell growth, pathological cholesterol profile, hypertension, and recruitment of immune cells to the endothelium, all contributing to atherosclerosis. DPP4 has pleiotropic functions and its activity is elevated in obese humans. DPP4 mirrors hyperinsulinemia's atherogenic actions in the insulin resistant state, and genetic deletion of DPP4 protects rodents from developing insulin resistance and improves cardiovascular outcomes. DPP4 inhibition in pro-atherosclerotic preclinical models results in reduced inflammation and oxidative stress, improved endothelial function, and decreased atherosclerosis. Increased incretin levels may have contributed to but do not completely account for these benefits. Small clinical studies with DPP4 inhibitors demonstrate reduced carotid intimal thickening, improved endothelial function, and reduced arterial stiffness. To date, this has not been translated to cardiovascular risk reduction for individuals with type 2 diabetes with prior or exaggerated risk of cardiovascular disease. CONCLUSION DPP4 may represent a key link between central obesity, insulin resistance, and atherosclerosis. The gaps in knowledge in DPP4 function and discrepancy in cardiovascular outcomes observed in preclinical and large-scale randomized controlled studies with DPP4 inhibitors warrant additional research.
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Affiliation(s)
- Kaitlin M Love
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
| | - Zhenqi Liu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
- Correspondence: Zhenqi Liu, M.D., University of Virginia Health System, Charlottesville, VA, USA.
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The osmo-metabolic approach: a novel and tantalizing glucose-sparing strategy in peritoneal dialysis. J Nephrol 2020; 34:503-519. [PMID: 32767274 PMCID: PMC8036224 DOI: 10.1007/s40620-020-00804-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
Abstract
Peritoneal dialysis (PD) is a viable but under-prescribed treatment for uremic patients. Concerns about its use include the bio-incompatibility of PD fluids, due to their potential for altering the functional and anatomical integrity of the peritoneal membrane. Many of these effects are thought to be due to the high glucose content of these solutions, with attendant issues of products generated during heat treatment of glucose-containing solutions. Moreover, excessive intraperitoneal absorption of glucose from the dialysate has many potential systemic metabolic effects. This article reviews the efforts to develop alternative PD solutions that obviate some of these side effects, through the replacement of part of their glucose content with other osmolytes which are at least as efficient in removing fluids as glucose, but less impactful on patient metabolism. In particular, we will summarize clinical studies on the use of alternative osmotic ingredients that are commercially available (icodextrin and amino acids) and preclinical studies on alternative solutions under development (taurine, polyglycerol, carnitine and xylitol). In addition to the expected benefit of a glucose-sparing approach, we describe an ‘osmo-metabolic’ approach in formulating novel PD solutions, in which there is the possibility of exploiting the pharmaco-metabolic properties of some of the osmolytes to attenuate the systemic side effects due to glucose. This approach has the potential to ameliorate pre-existing co-morbidities, including insulin resistance and type-2 diabetes, which have a high prevalence in the dialysis population, including in PD patients.
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Brown RB. Diabetes, Diabetic Complications, and Phosphate Toxicity: A Scoping Review. Curr Diabetes Rev 2020; 16:674-689. [PMID: 31686640 DOI: 10.2174/1573399815666191104113236] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/09/2019] [Accepted: 10/28/2019] [Indexed: 02/06/2023]
Abstract
This article presents a scoping review and synthesis of research findings investigating the toxic cellular accumulation of dysregulated inorganic phosphate-phosphate toxicity-as a pathophysiological determinant of diabetes and diabetic complications. Phosphorus, an essential micronutrient, is closely linked to the cellular metabolism of glucose for energy production, and serum inorganic phosphate is often transported into cells along with glucose during insulin therapy. Mitochondrial dysfunction and apoptosis, endoplasmic reticulum stress, neuronal degeneration, and pancreatic cancer are associated with dysregulated levels of phosphate in diabetes. Ectopic calcification involving deposition of calcium-phosphate crystals is prevalent throughout diabetic complications, including vascular calcification, nephropathy, retinopathy, and bone disorders. A low-glycemic, low-phosphate dietary intervention is proposed for further investigations in the treatment and prevention of diabetes and related diabetic pathologies.
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Affiliation(s)
- Ronald B Brown
- School of Public Health and Health Systems, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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7
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Kumar D, Shankar K, Patel S, Gupta A, Varshney S, Gupta S, Rajan S, Srivastava A, Vishwakarma AL, Gaikwad AN. Chronic hyperinsulinemia promotes meta-inflammation and extracellular matrix deposition in adipose tissue: Implications of nitric oxide. Mol Cell Endocrinol 2018; 477:15-28. [PMID: 29753026 DOI: 10.1016/j.mce.2018.05.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 01/02/2023]
Abstract
Various imperative studies support the notion that hyperinsulinemia (HI) itself serves as the common link between adipose tissue inflammation (ATI) and metabolic syndrome. However, the contribution of HI mediated ATI and its metabolic consequences are yet to be explored. We induced chronic HI per se in mice by administration of exogenous insulin for 8 weeks through mini-osmotic pumps. For the reduction of circulating insulin in response to excess calorie intake, we have partially ablated β-cells by using streptozotocin (STZ) in the diet-induced obesity (DIO) and genetic mice models (db/db). Flow cytometry analysis was performed for the quantification of immune cells in stromal vascular fraction (SVF) isolated from epididymal white adipose tissue (eWAT). Our studies demonstrated that chronic HI augmented ATI in terms of elevated pro-inflammatory cells (M1 macrophages and NK-cells) and suppressed anti-inflammatory cells (M2 macrophages, eosinophils and regulatory T-cells). These results were correlated with altered obesity-associated metabolic phenotype. Partial reduction of circulating insulin level attenuated excess calorie-induced ATI and improved insulin sensitivity. Mechanistically, an imbalance in M1 and M2 macrophage proportions in eWAT promoted iNOS (inducible nitric oxide synthase): arginase-1 imbalance that resulted into extracellular matrix (ECM) deposition and insulin resistance (IR) development. However, iNOS-/- mice were protected from HI-induced M1:M2 macrophage imbalance, ECM deposition and IR in adipose tissue. Overall, we conclude that chronic HI per se contributed in ATI and iNOS corroborated ECM deposition.
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Affiliation(s)
- Durgesh Kumar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Kripa Shankar
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Saraswati Patel
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Abhishek Gupta
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Salil Varshney
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Sanchita Gupta
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Sujith Rajan
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Ankita Srivastava
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India
| | - Achchhe Lal Vishwakarma
- Sophisticated Analytical Instrument Facility, CSIR-Central Drug Research Institute, Lucknow 226031, India
| | - Anil N Gaikwad
- Division of Pharmacology, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research, CSIR-CDRI, India.
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González-Mariscal I, Montoro RA, Doyle ME, Liu QR, Rouse M, O'Connell JF, Santa-Cruz Calvo S, Krzysik-Walker SM, Ghosh S, Carlson OD, Lehrmann E, Zhang Y, Becker KG, Chia CW, Ghosh P, Egan JM. Absence of cannabinoid 1 receptor in beta cells protects against high-fat/high-sugar diet-induced beta cell dysfunction and inflammation in murine islets. Diabetologia 2018; 61:1470-1483. [PMID: 29497784 PMCID: PMC6201315 DOI: 10.1007/s00125-018-4576-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/25/2018] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS The cannabinoid 1 receptor (CB1R) regulates insulin sensitivity and glucose metabolism in peripheral tissues. CB1R is expressed on pancreatic beta cells and is coupled to the G protein Gαi, suggesting a negative regulation of endogenous signalling in the beta cell. Deciphering the exact function of CB1R in beta cells has been confounded by the expression of this receptor on multiple tissues involved in regulating metabolism. Thus, in models of global genetic or pharmacological CB1R blockade, it is difficult to distinguish the indirect effects of improved insulin sensitivity in peripheral tissues from the direct effects of inhibiting CB1R in beta cells per se. To assess the direct contribution of beta cell CB1R to metabolism, we designed a mouse model that allows us to determine the role of CB1R specifically in beta cells in the context of whole-body metabolism. METHODS We generated a beta cell specific Cnr1 (CB1R) knockout mouse (β-CB1R-/-) to study the long-term consequences of CB1R ablation on beta cell function in adult mice. We measured beta cell function, proliferation and viability in these mice in response to a high-fat/high-sugar diet and induction of acute insulin resistance with the insulin receptor antagonist S961. RESULTS β-CB1R-/- mice had increased fasting (153 ± 23% increase at 10 weeks of age) and stimulated insulin secretion and increased intra-islet cAMP levels (217 ± 33% increase at 10 weeks of age), resulting in primary hyperinsulinaemia, as well as increased beta cell viability, proliferation and islet area (1.9-fold increase at 10 weeks of age). Hyperinsulinaemia led to insulin resistance, which was aggravated by a high-fat/high-sugar diet and weight gain, although beta cells maintained their insulin secretory capacity in response to glucose. Strikingly, islets from β-CB1R-/- mice were protected from diet-induced inflammation. Mechanistically, we show that this is a consequence of curtailment of oxidative stress and reduced activation of the NLRP3 inflammasome in beta cells. CONCLUSIONS/INTERPRETATION Our data demonstrate CB1R to be a negative regulator of beta cell function and a mediator of islet inflammation under conditions of metabolic stress. Our findings point to beta cell CB1R as a therapeutic target, and broaden its potential to include anti-inflammatory effects in both major forms of diabetes. DATA AVAILABILITY Microarray data have been deposited at GEO (GSE102027).
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Affiliation(s)
- Isabel González-Mariscal
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Rodrigo A Montoro
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Máire E Doyle
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Qing-Rong Liu
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Michael Rouse
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Jennifer F O'Connell
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Sara Santa-Cruz Calvo
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Susan M Krzysik-Walker
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Soumita Ghosh
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Olga D Carlson
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Elin Lehrmann
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Yongqing Zhang
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kevin G Becker
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Chee W Chia
- Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Paritosh Ghosh
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA
| | - Josephine M Egan
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD, 21224, USA.
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Zheng X, Niu S. Leptin-induced basal Akt phosphorylation and its implication in exercise-mediated improvement of insulin sensitivity. Biochem Biophys Res Commun 2017; 496:37-43. [PMID: 29294325 DOI: 10.1016/j.bbrc.2017.12.161] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 11/30/2022]
Abstract
Physical exercise is an efficient therapeutical tool in the management of insulin resistance (IR) and related metabolic diseases. Leptin, the well-known obesity hormone and the absence of which leads to IR, showed controversial effects on IR as research continues. Thus, in this study, a detailed investigation of the effect of leptin on exercise-mediated improvement of insulin sensitivity and its underlying mechanism was carried out. Using a rat model of chronic or acute swimming exercise training, we found that serum leptin increased 1 h after either acute exercise or the last session of chronic exercise, when impaired insulin action was observed in previous reports. However, chronic exercise reducd basal serum leptin levels and promoted insulin sensitivity compared with sedentary controls or rats subjected to one bout of aerobic exercise. Our animal results indicated the potential linkage between leptin and insulin sensitivity, which is further investigated in the skeletal muscle L6 cells. Leptin treatment in L6 cells promoted the basal levels of insulin signaling as well as glucose uptake, while blocking JAK2 signaling with either pharmacological intervention (JAK2 inhibitor AG490) or genetic manipulation (siRNA knockdown) decreased the basal levels of insulin signaling. Furthermore, leptin treatment inhibited insulin-stimulated insulin signaling and glucose uptake, while blocking JAK2 signaling restored leptin-attenuated insulin sensitivity. Taken together, our results demonstrated that reduced serum leptin, at least in part, contributes to exercise-mediated improvement of insulin sensitivity, indicating JAK2 as a potent therapeutical target of insulin resistance.
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Affiliation(s)
- Xianjie Zheng
- Foreign Trade and Business College, Chongqing Normal University, Chongqing, China.
| | - Sen Niu
- School of Physical Education, Hebei Normal University, Shijiazhuang, China; School of Physical Education, Shangqiu Normal University, Henan, China
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Russo L, Muturi HT, Ghadieh HE, Ghanem SS, Bowman TA, Noh HL, Dagdeviren S, Dogbey GY, Kim JK, Heinrich G, Najjar SM. Liver-specific reconstitution of CEACAM1 reverses the metabolic abnormalities caused by its global deletion in male mice. Diabetologia 2017; 60:2463-2474. [PMID: 28913658 PMCID: PMC5788286 DOI: 10.1007/s00125-017-4432-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 07/17/2017] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS The carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) promotes insulin clearance. Mice with global null mutation (Cc1 -/-) or with liver-specific inactivation (L-SACC1) of Cc1 (also known as Ceacam1) gene display hyperinsulinaemia resulting from impaired insulin clearance, insulin resistance, steatohepatitis and obesity. Because increased lipolysis contributes to the metabolic phenotype caused by transgenic inactivation of CEACAM1 in the liver, we aimed to further investigate the primary role of hepatic CEACAM1-dependent insulin clearance in insulin and lipid homeostasis. To this end, we examined whether transgenic reconstitution of CEACAM1 in the liver of global Cc1 -/- mutant mice reverses their abnormal metabolic phenotype. METHODS Insulin response was assessed by hyperinsulinaemic-euglycaemic clamp analysis and energy balance was analysed by indirect calorimetry. Mice were overnight-fasted and refed for 7 h to assess fatty acid synthase activity in the liver and the hypothalamus in response to insulin release during refeeding. RESULTS Liver-based rescuing of CEACAM1 restored insulin clearance, plasma insulin level, insulin sensitivity and steatohepatitis caused by global deletion of Cc1. It also reversed the gain in body weight and total fat mass observed with Cc1 deletion, in parallel to normalising energy balance. Mechanistically, reversal of hyperphagia appeared to result from reducing fatty acid synthase activity and restoring insulin signalling in the hypothalamus. CONCLUSIONS/INTERPRETATION Despite the potential confounding effects of deleting Cc1 from extrahepatic tissues, liver-based rescuing of CEACAM1 resulted in full normalisation of the metabolic phenotype, underscoring the key role that CEACAM1-dependent hepatic insulin clearance pathways play in regulating systemic insulin sensitivity, lipid homeostasis and energy balance.
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Affiliation(s)
- Lucia Russo
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Harrison T Muturi
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
| | - Hilda E Ghadieh
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Simona S Ghanem
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Thomas A Bowman
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Hye Lim Noh
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sezin Dagdeviren
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Godwin Y Dogbey
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
| | - Jason K Kim
- Division of Endocrinology, Metabolism and Diabetes, University of Massachusetts Medical School, Worcester, MA, USA
| | - Garrett Heinrich
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Sonia M Najjar
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Irvine Hall 229, 1 Ohio University, Athens, OH, 45701-2979, USA.
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA.
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11
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Morita I, Tanimoto K, Akiyama N, Naya N, Fujieda K, Iwasaki T, Yukioka H. Chronic hyperinsulinemia contributes to insulin resistance under dietary restriction in association with altered lipid metabolism in Zucker diabetic fatty rats. Am J Physiol Endocrinol Metab 2017; 312:E264-E272. [PMID: 28143857 DOI: 10.1152/ajpendo.00342.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/06/2017] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
Abstract
Hyperinsulinemia is widely thought to be a compensatory response to insulin resistance, whereas its potentially causal role in the progression of insulin resistance remains to be established. Here, we aimed to examine whether hyperinsulinemia could affect the progression of insulin resistance in Zucker fatty diabetic (ZDF) rats. Male ZDF rats at 8 wk of age were fed a diet ad libitum (AL) or dietary restriction (DR) of either 15 or 30% from AL feeding over 6 wk. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. ZDF rats in the AL group progressively developed hyperglycemia and hyperinsulinemia by 10 wk of age, and then plasma insulin rapidly declined to nearly normal levels by 12 wk of age. Compared with AL group, DR groups showed delayed onset of hyperglycemia and persistent hyperinsulinemia, leading to weight gain and raised plasma triglycerides and free fatty acids by 14 wk of age. Notably, insulin sensitivity was significantly reduced in the DR group rather than the AL group and inversely correlated with plasma levels of insulin and triglyceride but not glucose. Moreover, enhanced lipid deposition and upregulation of genes involved in lipogenesis were detected in liver, skeletal muscle, and adipose tissues of the DR group rather than the AL group. Alternatively, continuous hyperinsulinemia induced by insulin pellet implantation produced a decrease in insulin sensitivity in ZDF rats. These results suggest that chronic hyperinsulinemia may lead to the progression of insulin resistance under DR conditions in association with altered lipid metabolism in peripheral tissues in ZDF rats.
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Affiliation(s)
- Ippei Morita
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Keiichi Tanimoto
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Nobuteru Akiyama
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Noriyuki Naya
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Kumiko Fujieda
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Takanori Iwasaki
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
| | - Hideo Yukioka
- Drug Discovery and Disease Research Laboratory, Shionogi and Company, Ltd., Osaka, Japan
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12
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Minard AY, Wong MKL, Chaudhuri R, Tan SX, Humphrey SJ, Parker BL, Yang JY, Laybutt DR, Cooney GJ, Coster ACF, Stöckli J, James DE. Hyperactivation of the Insulin Signaling Pathway Improves Intracellular Proteostasis by Coordinately Up-regulating the Proteostatic Machinery in Adipocytes. J Biol Chem 2016; 291:25629-25640. [PMID: 27738101 DOI: 10.1074/jbc.m116.741140] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/11/2016] [Indexed: 01/25/2023] Open
Abstract
Hyperinsulinemia, which is associated with aging and metabolic disease, may lead to defective protein homeostasis (proteostasis) due to hyperactivation of insulin-sensitive pathways such as protein synthesis. We investigated the effect of chronic hyperinsulinemia on proteostasis by generating a time-resolved map of insulin-regulated protein turnover in adipocytes using metabolic pulse-chase labeling and high resolution mass spectrometry. Hyperinsulinemia increased the synthesis of nearly half of all detected proteins and did not affect protein degradation despite suppressing autophagy. Unexpectedly, this marked elevation in protein synthesis was accompanied by enhanced protein stability and folding and not by markers of proteostasis stress such as protein carbonylation and aggregation. The improvement in proteostasis was attributed to a coordinate up-regulation of proteins in the global proteostasis network, including ribosomal, proteasomal, chaperone, and endoplasmic reticulum/mitochondrial unfolded protein response proteins. We conclude that defects associated with hyperactivation of the insulin signaling pathway are unlikely attributed to defective proteostasis because up-regulation of protein synthesis by insulin is accompanied by up-regulation of proteostatic machinery.
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Affiliation(s)
- Annabel Y Minard
- From The Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia.,Charles Perkins Centre, School of Life Environmental Sciences
| | - Martin K L Wong
- From The Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia.,Charles Perkins Centre, School of Life Environmental Sciences.,School of Physics
| | - Rima Chaudhuri
- Charles Perkins Centre, School of Life Environmental Sciences
| | - Shi-Xiong Tan
- From The Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
| | - Sean J Humphrey
- Charles Perkins Centre, School of Life Environmental Sciences
| | | | | | - D Ross Laybutt
- From The Garvan Institute of Medical Research, Sydney, New South Wales 2010, Australia
| | | | - Adelle C F Coster
- Department of Applied Mathematics, School of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales 2052, Australia
| | | | - David E James
- Charles Perkins Centre, School of Life Environmental Sciences, .,School of Medicine, University of Sydney, Sydney, New South Wales 2006, Australia, and
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13
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Rajan S, Shankar K, Beg M, Varshney S, Gupta A, Srivastava A, Kumar D, Mishra RK, Hussain Z, Gayen JR, Gaikwad AN. Chronic hyperinsulinemia reduces insulin sensitivity and metabolic functions of brown adipocyte. J Endocrinol 2016; 230:275-90. [PMID: 27340034 DOI: 10.1530/joe-16-0099] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 06/22/2016] [Indexed: 01/02/2023]
Abstract
The growing pandemics of diabetes have become a real threat to world economy. Hyperinsulinemia and insulin resistance are closely associated with the pathophysiology of type 2 diabetes. In pretext of brown adipocytes being considered as the therapeutic strategy for the treatment of obesity and insulin resistance, we have tried to understand the effect of hyperinsulinemia on brown adipocyte function. We here with for the first time report that hyperinsulinemia-induced insulin resistance in brown adipocyte is also accompanied with reduced insulin sensitivity and brown adipocyte characteristics. CI treatment decreased expression of brown adipocyte-specific markers (such as PRDM16, PGC1α, and UCP1) and mitochondrial content as well as activity. CI-treated brown adipocytes showed drastic decrease in oxygen consumption rate (OCR) and spare respiratory capacity. Morphological study indicates increased accumulation of lipid droplets in CI-treated brown adipocytes. We have further validated these findings in vivo in C57BL/6 mice implanted with mini-osmotic insulin pump for 8weeks. CI treatment in mice leads to increased body weight gain, fat mass and impaired glucose intolerance with reduced energy expenditure and insulin sensitivity. CI-treated mice showed decreased BAT characteristics and function. We also observed increased inflammation and ER stress markers in BAT of CI-treated animals. The above results conclude that hyperinsulinemia has deleterious effect on brown adipocyte function, making it susceptible to insulin resistance. Thus, the above findings have greater implication in designing approaches for the treatment of insulin resistance and diabetes via recruitment of brown adipocytes.
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Affiliation(s)
- Sujith Rajan
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India Academy of Scientific and Innovative ResearchCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Kripa Shankar
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Muheeb Beg
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Salil Varshney
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Abhishek Gupta
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Ankita Srivastava
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India Academy of Scientific and Innovative ResearchCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Durgesh Kumar
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India Academy of Scientific and Innovative ResearchCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Raj K Mishra
- SIPS Superspeciality HospitalLucknow, Uttar Pradesh, India
| | - Zakir Hussain
- Division of PharmacokineticsCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Jiaur R Gayen
- Division of PharmacokineticsCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Anil N Gaikwad
- Division of PharmacologyCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India Academy of Scientific and Innovative ResearchCSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
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14
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Sah SP, Singh B, Choudhary S, Kumar A. Animal models of insulin resistance: A review. Pharmacol Rep 2016; 68:1165-1177. [PMID: 27639595 DOI: 10.1016/j.pharep.2016.07.010] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 12/22/2022]
Abstract
Insulin resistance can be seen as a molecular and genetic mystery, with a role in the pathophysiology of type 2 diabetes mellitus. It is a basis for a number of chronic diseases like hypertension, dyslipidemia, glucose intolerance, coronary heart disease, cerebral vascular disease along with T2DM, thus the key is to cure and prevent insulin resistance. Critical perspicacity into the etiology of insulin resistance have been gained by the use of animal models where insulin action has been modulated by various transgenic and non-transgenic models which is not possible in human studies. The following review comprises the pathophysiology involved in insulin resistance, various factors causing insulin resistance, their screening and various genetic and non-genetic animal models highlighting the pathological and metabolic characteristics of each.
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Affiliation(s)
- Sangeeta Pilkhwal Sah
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India.
| | - Barinder Singh
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
| | - Supriti Choudhary
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
| | - Anil Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, 160014, India
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15
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Schwartz SS, Jellinger PS, Herman ME. Obviating much of the need for insulin therapy in type 2 diabetes mellitus: A re-assessment of insulin therapy’s safety profile. Postgrad Med 2016; 128:609-19. [DOI: 10.1080/00325481.2016.1191955] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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16
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Hasson BR, Apovian C, Istfan N. Racial/Ethnic Differences in Insulin Resistance and Beta Cell Function: Relationship to Racial Disparities in Type 2 Diabetes among African Americans versus Caucasians. Curr Obes Rep 2015; 4:241-9. [PMID: 26627219 DOI: 10.1007/s13679-015-0150-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Both biological and sociocultural factors have been implicated in the well-documented racial disparity in incidence and prevalence of type 2 diabetes (T2D) between African Americans (AA) and non-Hispanic whites (NHW). This review examines the extent to which biological differences in glucose metabolism, specifically insulin resistance and beta cell function (BCF), contribute to this disparity. The majority of available data suggests that AA are more insulin resistant and have upregulated BCF compared to NHW. Increasing evidence implicates high insulin secretion as a cause rather than consequence of T2D; therefore, upregulated BCF in AA may specifically confer increased risk of T2D in this cohort. Racial disparities in the metabolic characteristics of T2D have direct implications for the treatment and health consequences of this disease; therefore, future research is needed to determine whether strategies to reduce insulin secretion in AA may prevent or delay T2D and lessen racial health disparities.
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Affiliation(s)
- Brooke R Hasson
- Division of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, 88 East Newton Street, Boston, MA, 02118, USA.
| | - Caroline Apovian
- Division of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, 88 East Newton Street, Boston, MA, 02118, USA.
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