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Oteng AB, Liu L. GPCR-mediated effects of fatty acids and bile acids on glucose homeostasis. Front Endocrinol (Lausanne) 2023; 14:1206063. [PMID: 37484954 PMCID: PMC10360933 DOI: 10.3389/fendo.2023.1206063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 06/20/2023] [Indexed: 07/25/2023] Open
Abstract
Fatty acids and glucose are key biomolecules that share several commonalities including serving as energy substrates and as signaling molecules. Fatty acids can be synthesized endogenously from intermediates of glucose catabolism via de-novo lipogenesis. Bile acids are synthesized endogenously in the liver from the biologically important lipid molecule, cholesterol. Evidence abounds that fatty acids and bile acids play direct and indirect roles in systemic glucose homeostasis. The tight control of plasma glucose levels during postprandial and fasted states is principally mediated by two pancreatic hormones, insulin and glucagon. Here, we summarize experimental studies on the endocrine effects of fatty acids and bile acids, with emphasis on their ability to regulate the release of key hormones that regulate glucose metabolism. We categorize the heterogenous family of fatty acids into short chain fatty acids (SCFAs), unsaturated, and saturated fatty acids, and highlight that along with bile acids, these biomolecules regulate glucose homeostasis by serving as endogenous ligands for specific G-protein coupled receptors (GPCRs). Activation of these GPCRs affects the release of incretin hormones by enteroendocrine cells and/or the secretion of insulin, glucagon, and somatostatin by pancreatic islets, all of which regulate systemic glucose homeostasis. We deduce that signaling induced by fatty acids and bile acids is necessary to maintain euglycemia to prevent metabolic diseases such as type-2 diabetes and related metabolic disorders.
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Zhu J, Han J, Liu L, Liu Y, Xu W, Li X, Yang L, Gu Y, Tang W, Shi Y, Ye S, Hua F, Xiang G, Liu M, Sun Z, Su Q, Li X, Li Y, Li Y, Li H, Li Y, Yang T, Yang J, Shi L, Yu X, Chen L, Shao J, Liang J, Han X, Xue Y, Ma J, Zhu D, Mu Y. Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus. Diabetes Res Clin Pract 2023; 197:110568. [PMID: 36738836 DOI: 10.1016/j.diabres.2023.110568] [Citation(s) in RCA: 3] [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: 09/08/2022] [Revised: 01/08/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
Islet β-cell dysfunction is a basic pathophysiological characteristic of type 2 diabetes mellitus (T2DM). Appropriate assessment of islet β-cell function is beneficial to better management of T2DM. Protecting islet β-cell function is vital to delay the progress of type 2 diabetes mellitus. Therefore, the Pancreatic Islet β-cell Expert Panel of the Chinese Diabetes Society and Endocrinology Society of Jiangsu Medical Association organized experts to draft the "Clinical expert consensus on the assessment and protection of pancreatic islet β-cell function in type 2 diabetes mellitus." This consensus suggests that β-cell function can be clinically assessed using blood glucose-based methods or methods that combine blood glucose and endogenous insulin or C-peptide levels. Some measures, including weight loss and early and sustained euglycemia control, could effectively protect islet β-cell function, and some newly developed drugs, such as Sodium-glucose cotransporter-2 inhibitor and Glucagon-like peptide-1 receptor agonists, could improve islet β-cell function, independent of glycemic control.
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Affiliation(s)
- Jian Zhu
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Junfeng Han
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Disease, Shanghai, China
| | - Liehua Liu
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yu Liu
- Endocrinology Department, Sir Run Run Hospital of Nanjing Medical University, Nanjing, China
| | - Wen Xu
- Department of Endocrinology and Metabolism, Guangdong Provincial Key Laboratory of Diabetology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaomu Li
- Department of Endocrine and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lin Yang
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology, Ministry of Education, Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yong Gu
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Tang
- Department of Endocrinology, Geriatric Hospital of Nanjing Medical University, Nanjing, China
| | - Yongquan Shi
- Department of Endocrinology, Changzheng Hospital, The Navy Military Medical University, Shanghai, China
| | - Shandong Ye
- Department of Endocrinology, Anhui Provincial Hospital, Hefei, China
| | - Fei Hua
- Department of Endocrinology, The First People's Hospital of Changzhou, Changzhou, China
| | - Guangda Xiang
- Department of Endocrinology, General Hospital of Central Theater Command of Chinese People' s Liberation Army, Wuhan, China
| | - Ming Liu
- Department of Endocrinology, General Hospital, Tianjin Medical University, Tianjin, China
| | - Zilin Sun
- Department of Endocrinology, Zhongda Hospital, Institute of Diabetes, School of Medicine, Southeast University, Nanjing, China
| | - Qing Su
- Department of Endocrinology, Xinhua Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Xiaoying Li
- Department of Endocrine and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuxiu Li
- Department of Endocrinology, Peking Union Medical College Hospital, Beijing, China
| | - Yanbing Li
- Department of Endocrinology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Hong Li
- Department of Endocrinology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yiming Li
- Department of Endocrinology, Huashan Hospital, Fudan University, Shanghai, China
| | - Tao Yang
- Department of Endocrinology and Metabolism, First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jing Yang
- Department of Endocrinology, First Hospital of Shanxi Medical University, Taiyuan, China
| | - Lixin Shi
- Department of Endocrinology, Guiqian International General Hospital, Guiyang 550018, China
| | - Xuefeng Yu
- Department of Endocrinology, Tongji Hospital, Tongji Medical College of Huazhong University of Science & Technology, Wuhan, China
| | - Li Chen
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, China
| | - Jiaqing Shao
- Department of Endocrinology, the Affiliated Jinling Hospital of Nanjing Medical University, General Hospital of Eastern Theater Command, Nanjing, China
| | - Jun Liang
- Department of Endocrinology, Xuzhou Central Hospital, Xuzhou, China
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Yaomin Xue
- The First Clinical Medical Institute, Southern Medical University, Guangzhou, China
| | - Jianhua Ma
- Department of Endocrinology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.
| | - Dalong Zhu
- Department of Endocrinology, Drum Tower Hospital Affiliated to Nanjing University Medical School, Nanjing, China.
| | - Yiming Mu
- Department of Endocrinology, Chinese PLA General Hospital, Beijing, China.
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Henquin JC. Non-glucose modulators of insulin secretion in healthy humans: (dis)similarities between islet and in vivo studies. Metabolism 2021; 122:154821. [PMID: 34174327 DOI: 10.1016/j.metabol.2021.154821] [Citation(s) in RCA: 4] [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: 04/16/2021] [Revised: 06/10/2021] [Accepted: 06/18/2021] [Indexed: 12/17/2022]
Abstract
Optimal metabolic homeostasis requires precise temporal and quantitative control of insulin secretion. Both in vivo and in vitro studies have often focused on the regulation by glucose although many additional factors including other nutrients, neurotransmitters, hormones and drugs, modulate the secretory function of pancreatic β-cells. This review is based on the analysis of clinical investigations characterizing the effects of non-glucose modulators of insulin secretion in healthy subjects, and of experimental studies testing the same modulators in islets isolated from normal human donors. The aim was to determine whether the information gathered in vitro can reliably be translated to the in vivo situation. The comparison evidenced both convincing similarities and areas of discordance. The lack of coherence generally stems from the use of exceedingly high concentrations of test agents at too high or too low glucose concentrations in vitro, which casts doubts on the physiological relevance of a number of observations made in isolated islets. Future projects resorting to human islets should avoid extreme experimental conditions, such as oversized stimulations or inhibitions of β-cells, which are unlikely to throw light on normal insulin secretion and contribute to the elucidation of its defects.
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Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium.
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Sarsenbayeva A, Jui BN, Fanni G, Barbosa P, Ahmed F, Kristófi R, Cen J, Chowdhury A, Skrtic S, Bergsten P, Fall T, Eriksson JW, Pereira MJ. Impaired HMG-CoA Reductase Activity Caused by Genetic Variants or Statin Exposure: Impact on Human Adipose Tissue, β-Cells and Metabolome. Metabolites 2021; 11:574. [PMID: 34564389 PMCID: PMC8468287 DOI: 10.3390/metabo11090574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 11/20/2022] Open
Abstract
Inhibition of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase is associated with an increased risk of new-onset type 2 diabetes. We studied the association of genetic or pharmacological HMG-CoA reductase inhibition with plasma and adipose tissue (AT) metabolome and AT metabolic pathways. We also investigated the effects of statin-mediated pharmacological inhibition of HMG-CoA reductase on systemic insulin sensitivity by measuring the HOMA-IR index in subjects with or without statin therapy. The direct effects of simvastatin (20-250 nM) or its active metabolite simvastatin hydroxy acid (SA) (8-30 nM) were investigated on human adipocyte glucose uptake, lipolysis, and differentiation and pancreatic insulin secretion. We observed that the LDL-lowering HMGCR rs12916-T allele was negatively associated with plasma phosphatidylcholines and sphingomyelins, and HMGCR expression in AT was correlated with various metabolic and mitochondrial pathways. Clinical data showed that statin treatment was associated with HOMA-IR index after adjustment for age, sex, BMI, HbA1c, LDL-c levels, and diabetes status in the subjects. Supra-therapeutic concentrations of simvastatin reduced glucose uptake in adipocytes and normalized fatty acid-induced insulin hypersecretion from β-cells. Our data suggest that inhibition of HMG-CoA reductase is associated with insulin resistance. However, statins have a very mild direct effect on AT and pancreas, hence, other tissues as the liver or muscle appear to be of greater importance.
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Affiliation(s)
- Assel Sarsenbayeva
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Bipasha Nandi Jui
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Giovanni Fanni
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Pedro Barbosa
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal;
- Institute for Interdisciplinary Research, University of Coimbra, 3030-789 Coimbra, Portugal
| | - Fozia Ahmed
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Robin Kristófi
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Jing Cen
- Department of Medical Cell Biology, Uppsala University, 751 85 Uppsala, Sweden; (J.C.); (A.C.); (P.B.)
| | - Azazul Chowdhury
- Department of Medical Cell Biology, Uppsala University, 751 85 Uppsala, Sweden; (J.C.); (A.C.); (P.B.)
| | - Stanko Skrtic
- Innovation Strategies & External Liaison, Pharmaceutical Technologies & Development, AstraZeneca, 431 83 Gothenburg, Sweden;
- Institute of Medicine at Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Peter Bergsten
- Department of Medical Cell Biology, Uppsala University, 751 85 Uppsala, Sweden; (J.C.); (A.C.); (P.B.)
| | - Tove Fall
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Jan W. Eriksson
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
| | - Maria J. Pereira
- Department of Medical Sciences, Clinical Diabetology and Metabolism, Uppsala University, 751 85 Uppsala, Sweden; (A.S.); (B.N.J.); (G.F.); (F.A.); (R.K.); (T.F.); (J.W.E.)
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Marrano N, Biondi G, Cignarelli A, Perrini S, Laviola L, Giorgino F, Natalicchio A. Functional loss of pancreatic islets in type 2 diabetes: How can we halt it? Metabolism 2020; 110:154304. [PMID: 32599081 DOI: 10.1016/j.metabol.2020.154304] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 06/14/2020] [Accepted: 06/25/2020] [Indexed: 02/08/2023]
Abstract
The loss of beta-cell functional mass is a necessary and early condition in the development of type 2 diabetes (T2D). In T2D patients, beta-cell function is already reduced by about 50% at diagnosis and further declines thereafter. Beta-cell mass is also reduced in subjects with T2D, and islets from diabetic donors are smaller compared to non-diabetic donors. Thus, beta-cell regeneration and/or preservation of the functional islet integrity should be highly considered for T2D treatment and possibly cure. To date, the available anti-diabetes drugs have been developed as "symptomatic" medications since they act to primarily reduce elevated blood glucose levels. However, a truly efficient anti-diabetes medication, capable to prevent the onset and progression of T2D, should stop beta-cell loss and/or promote the restoration of fully functional beta-cell mass, independently of reducing hyperglycemia and ameliorating glucotoxicity on the pancreatic islets. This review provides a view of the experimental and clinical evidence on the ability of available anti-diabetes drugs to exert protective effects on beta-cells, with a specific focus on human pancreatic islets and clinical trials. Potential explanations for the lack of concordance between evidence of beta-cell protection in vitro and of persistent amelioration of beta-cell function in vivo are also discussed.
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Affiliation(s)
- Nicola Marrano
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Giuseppina Biondi
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Angelo Cignarelli
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy
| | - Sebastio Perrini
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Luigi Laviola
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Francesco Giorgino
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
| | - Annalisa Natalicchio
- Department of Emergency and Organ Transplantation, Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, University of Bari Aldo Moro, Bari, Italy.
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Lytrivi M, Castell AL, Poitout V, Cnop M. Recent Insights Into Mechanisms of β-Cell Lipo- and Glucolipotoxicity in Type 2 Diabetes. J Mol Biol 2019; 432:1514-1534. [PMID: 31628942 DOI: 10.1016/j.jmb.2019.09.016] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/15/2019] [Accepted: 09/16/2019] [Indexed: 12/24/2022]
Abstract
The deleterious effects of chronically elevated free fatty acid (FFA) levels on glucose homeostasis are referred to as lipotoxicity, and the concurrent exposure to high glucose may cause synergistic glucolipotoxicity. Lipo- and glucolipotoxicity have been studied for over 25 years. Here, we review the current evidence supporting the role of pancreatic β-cell lipo- and glucolipotoxicity in type 2 diabetes (T2D), including lipid-based interventions in humans, prospective epidemiological studies, and human genetic findings. In addition to total FFA quantity, the quality of FFAs (saturation and chain length) is a key determinant of lipotoxicity. We discuss in vitro and in vivo experimental models to investigate lipo- and glucolipotoxicity in β-cells and describe experimental pitfalls. Lipo- and glucolipotoxicity adversely affect many steps of the insulin production and secretion process. The molecular mechanisms underpinning lipo- and glucolipotoxic β-cell dysfunction and death comprise endoplasmic reticulum stress, oxidative stress and mitochondrial dysfunction, impaired autophagy, and inflammation. Crosstalk between these stress pathways exists at multiple levels and may aggravate β-cell lipo- and glucolipotoxicity. Lipo- and glucolipotoxicity are therapeutic targets as several drugs impact the underlying stress responses in β-cells, potentially contributing to their glucose-lowering effects in T2D.
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Affiliation(s)
- Maria Lytrivi
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Anne-Laure Castell
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Vincent Poitout
- CRCHUM, Montréal, QC, Canada; Department of Medicine, Université de Montréal, Montréal, QC, Canada.
| | - Miriam Cnop
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium; Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium.
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Son DO, Liu W, Li X, Prud'homme GJ, Wang Q. Combined effect of GABA and glucagon-like peptide-1 receptor agonist on cytokine-induced apoptosis in pancreatic β-cell line and isolated human islets. J Diabetes 2019; 11:563-572. [PMID: 30520247 DOI: 10.1111/1753-0407.12881] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/19/2018] [Accepted: 11/23/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Treatment with GABA or glucagon-like peptide-1 (GLP-1) can preserve pancreatic β-cell mass and prevent diabetes. Recently, we reported that the combination of GABA and sitagliptin (a dipeptidyl peptidase-4 inhibitor that increases endogenous GLP-1) was more effective than either agent alone in reducing drug-induced β-cell damage and promoting β-cell regeneration in mice. However, in human islets, it remains unclear whether GABA and GLP-1 exert similar effects. METHODS To investigate GABA and GLP-1 interactions, human islets or INS-1 cells were treated with GABA and/or exendin-4, a GLP-1 receptor agonist (GLP-1RA) in clinical use, and incubated with a cytokine mixture for 24 hours. Cleaved caspase-3 and annexin V binding were measured by western blot and flow cytometry analysis, respectively, to investigate effects on cytokine-induced apoptosis. RESULTS Cytokine-induced apoptosis was reduced by either GABA or exendin-4 alone. This was markedly improved by combining GABA and exendin-4, resulting in a reversal of apoptosis. The combination notably increased Akt pathway signaling. Furthermore, sirtuin-1 (SIRT1) and α-Klotho, both reported to have protective effects on β-cells, were increased. Importantly, the combination ameliorated insulin secretion by human β-cells. CONCLUSIONS The combination of GABA and a GLP-1RA exerted additive effects on β-cell survival and function, suggesting that this combination may be superior to either drug alone in the treatment of diabetes.
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Affiliation(s)
- Dong Ok Son
- Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Canada
- Laboratory of Tissue Repair and Regeneration, Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Wenjuan Liu
- Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Canada
- Department of Endocrinology, Huashan Hospital, Medical School, Fudan University, Shanghai, China
| | - Xiaoming Li
- Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Canada
| | - Gerald J Prud'homme
- Department of Laboratory Medicine, St. Michael's Hospital, Toronto
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Qinghua Wang
- Division of Endocrinology and Metabolism, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Canada
- Department of Endocrinology, Huashan Hospital, Medical School, Fudan University, Shanghai, China
- Department of Physiology, University of Toronto, Toronto, Canada
- Department of Medicine, University of Toronto, Toronto, Canada
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Lu L, Ye X, Yao Q, Lu A, Zhao Z, Ding Y, Meng C, Yu W, Du Y, Cheng J. Egr2 enhances insulin resistance via JAK2/STAT3/SOCS-1 pathway in HepG2 cells treated with palmitate. Gen Comp Endocrinol 2018; 260:25-31. [PMID: 28842216 DOI: 10.1016/j.ygcen.2017.08.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 08/05/2017] [Accepted: 08/21/2017] [Indexed: 01/21/2023]
Abstract
Insulin resistance is generally responsible for the pathogenesis of type 2 diabetes mellitus (T2DM). Early growth response proteins-2 (Egr2) has been reported to be able to increase the expression of the suppressors of cytokine signaling-1 (SOCS-1), and impair insulin signaling pathway through suppression of insulin receptor substrates (IRS), including IRS-1 and IRS-2. However, whether Egr2 is directly involved in the development of insulin resistance, and how its potential contributions to insulin resistance still remain unknown. Here, our present investigation found that the expression levels of Egr2 were up-regulated when insulin resistance occurs, and knockdown of Egr2 abolished the effect of insulin resistance in HepG2 cells induced with palmitate (PA). Importantly, inhibition of Egr2 decreased the expression of SOCS-1 as well as reduced phosphorylation of JAK2 and STAT3. And, our data indicated that silencing of Egr2 accelerated hepatic glucose uptake and reversed the impaired lipid metabolism upon insulin resistance. In summary, the present study confirms that Egr2 could deteriorate insulin resistance via the pathway of JAK2/STAT3/SOCS-1 and may shed light on resolving insulin resistance and further the pathogenesis of T2DM.
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Affiliation(s)
- Lin Lu
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Xinhua Ye
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Qing Yao
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Aijiao Lu
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Zhen Zhao
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Yang Ding
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Chuchen Meng
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Wenlong Yu
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - Yunfeng Du
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China
| | - JinLuo Cheng
- Department of Endocrinology, Changzhou Second People's Hospital Affiliated Nanjing Medical University, No.29 Xinglong Road, 213003 Changzhou, Jiangsu, People's Republic of China.
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9
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Sun X, Li S, Xu L, Wang H, Ma Z, Fu Q, Qu R, Ma S. Paeoniflorin ameliorates cognitive dysfunction via regulating SOCS2/IRS-1 pathway in diabetic rats. Physiol Behav 2017; 174:162-169. [PMID: 28322909 DOI: 10.1016/j.physbeh.2017.03.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/27/2017] [Accepted: 03/15/2017] [Indexed: 01/04/2023]
Abstract
Paeoniflorin is a natural monoterpene glycoside in Paeonia lactiflora pall with various biological properties including promising anti-inflammatory activity. Current evidences support that inflammatory reaction, oxidative stress, as well as abnormal insulin signaling in the hippocampus are potential causes of tau hyperphosphorylation and finally induce cognitive dysfunction. The present study aims to explore the effects of paeoniflorin on the cognitive deficits and investigate the underlying mechanisms in diabetic rats induced by a high-sucrose, high-fat diet and low dose of streptozotocin (STZ). Paeoniflorin treatment effectively improved the performance of diabetic rats in the Morris water maze test via decreasing escape latency and increasing the spent time in the target quadrant. Immunohistochemistry staining also had shown that tau hyperphosphorylation in the hippocampus was prevented after paeoniflorin administration. This function was correlated with its abilities of reducing the brain inflammatory cytokines (IL-1β and TNF-α), decreasing suppressor of cytokine signaling 2 (SOCS2) expressions and promoting insulin receptor substrate-1 (IRS-1) activity. Additionally, we also found paeoniflorin administration significantly promoted the phosphorylation levels of protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β). Together, these results showed that paeoniflorin had beneficial effects on relieving diabetes-associated cognitive deficits via regulating SOCS2/IRS-1 pathway and might provide a feasible method for the treatment of diabetes-associated cognitive dysfunction.
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Affiliation(s)
- Xiaoxu Sun
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Shanshan Li
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Lixing Xu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Hao Wang
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Zhanqiang Ma
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Qiang Fu
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China
| | - Rong Qu
- Department of Pharmacology of Traditional Chinese Medical Formulae, Nanjing University of Traditional Chinese Medicine, 138, Xianlin Road, Nanjing 210029, China
| | - Shiping Ma
- Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, 639, Longmian Road, Nanjing 211198, China.
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