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Roy S, Pokharel P, Piganelli JD. Decoding the immune dance: Unraveling the interplay between beta cells and type 1 diabetes. Mol Metab 2024; 88:101998. [PMID: 39069156 PMCID: PMC11342121 DOI: 10.1016/j.molmet.2024.101998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 07/12/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024] Open
Abstract
BACKGROUND Type 1 diabetes (T1D) is an autoimmune disease characterized by the specific destruction of insulin-producing beta cells in the pancreas by the immune system, including CD4 cells which orchestrate the attack and CD8 cells which directly destroy the beta cells, resulting in the loss of glucose homeostasis. SCOPE OF REVIEW This comprehensive document delves into the complex interplay between the immune system and beta cells, aiming to shed light on the mechanisms driving their destruction in T1D. Insights into the genetic predisposition, environmental triggers, and autoimmune responses provide a foundation for understanding the autoimmune attack on beta cells. From the role of viral infections as potential triggers to the inflammatory response of beta cells, an intricate puzzle starts to unfold. This exploration highlights the importance of beta cells in breaking immune tolerance and the factors contributing to their targeted destruction. Furthermore, it examines the potential role of autophagy and the impact of cytokine signaling on beta cell function and survival. MAJOR CONCLUSIONS This review collectively represents current research findings on T1D which offers valuable perspectives on novel therapeutic approaches for preserving beta cell mass, restoring immune tolerance, and ultimately preventing or halting the progression of T1D. By unraveling the complex dynamics between the immune system and beta cells, we inch closer to a comprehensive understanding of T1D pathogenesis, paving the way for more effective treatments and ultimately a cure.
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Affiliation(s)
- Saptarshi Roy
- Department of Endocrinology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Pravil Pokharel
- Department of Endocrinology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Jon D Piganelli
- Department of Endocrinology, Indiana University School of Medicine, Indianapolis, IN, 46202, United States.
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2
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Zeng S, Wang Y, Ai L, Huang L, Liu Z, He C, Bai Q, Li Y. Chronic intermittent hypoxia-induced oxidative stress activates TRB3 and phosphorylated JNK to mediate insulin resistance and cell apoptosis in the pancreas. Clin Exp Pharmacol Physiol 2024; 51:e13843. [PMID: 38302075 DOI: 10.1111/1440-1681.13843] [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: 08/07/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 02/03/2024]
Abstract
This study explores the potential mechanisms of obstructive sleep apnoea (OSA) complicates type 2 diabetes mellitus (T2DM) by which chronic intermittent hypoxia (CIH) induces insulin resistance and cell apoptosis in the pancreas through oxidative stress. Four- and eight-week CIH rat models were established, and Tempol (100 mg/kg/d), was used as an oxidative stress inhibitor. This study included five groups: 4-week CIH, 4-week CIH-Tempol, 8-week CIH, 8-week CIH-Tempol and normal control (NC) groups. Fasting blood glucose and insulin levels were measured in the serum. The expression levels of 8-hidroxy-2-deoxyguanosine (8-OHdG), tribbles homologue 3 (TRB3), c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), insulin receptor substrate-1 (IRS-1), phosphorylated IRS-1 (Ser307) (p-IRS-1ser307 ), protein kinase B (AKT), phosphorylated AKT (Ser473) (p-AKTser473 ), B cell lymphoma protein-2 (Bcl-2), cleaved-caspase-3 (Cl-caspase-3), and the islet cell apoptosis were detected in the pancreas. CIH induced oxidative stress in the pancreas. Compared with that in the NC group and CIH-Tempol groups individually, the homeostasis model assessment of insulin resistance (HOMA-IR) and apoptosis of islet cells was increased in the CIH groups. CIH-induced oxidative stress increased the expression of p-IRS-1Ser307 and decreased the expression of p-AKTSer473 . The expression levels of TRB3 and p-JNK were higher in the CIH groups than in both the CIH-Tempol and NC groups. Meanwhile, the expressions of Cl-caspase-3 and Bcl-2 were upregulated and downregulated, respectively, in the CIH groups. Hence, the present study demonstrated that CIH-induced oxidative stress might not only induce insulin resistance but also islet cell apoptosis in the pancreas through TRB3 and p-JNK.
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Affiliation(s)
- Shan Zeng
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yeying Wang
- Department of Epidemiology and Biostatistics, School of Public Health, Kunming Medical University, Kunming, China
| | - Li Ai
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Liwei Huang
- Department of Epidemiology and Biostatistics, School of Public Health, Kunming Medical University, Kunming, China
| | - Zhijuan Liu
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Chunxia He
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Qiaohui Bai
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yongxia Li
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
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Yan H, He L, Lv D, Yang J, Yuan Z. The Role of the Dysregulated JNK Signaling Pathway in the Pathogenesis of Human Diseases and Its Potential Therapeutic Strategies: A Comprehensive Review. Biomolecules 2024; 14:243. [PMID: 38397480 PMCID: PMC10887252 DOI: 10.3390/biom14020243] [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: 12/06/2023] [Revised: 02/12/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
JNK is named after c-Jun N-terminal kinase, as it is responsible for phosphorylating c-Jun. As a member of the mitogen-activated protein kinase (MAPK) family, JNK is also known as stress-activated kinase (SAPK) because it can be activated by extracellular stresses including growth factor, UV irradiation, and virus infection. Functionally, JNK regulates various cell behaviors such as cell differentiation, proliferation, survival, and metabolic reprogramming. Dysregulated JNK signaling contributes to several types of human diseases. Although the role of the JNK pathway in a single disease has been summarized in several previous publications, a comprehensive review of its role in multiple kinds of human diseases is missing. In this review, we begin by introducing the landmark discoveries, structures, tissue expression, and activation mechanisms of the JNK pathway. Next, we come to the focus of this work: a comprehensive summary of the role of the deregulated JNK pathway in multiple kinds of diseases. Beyond that, we also discuss the current strategies for targeting the JNK pathway for therapeutic intervention and summarize the application of JNK inhibitors as well as several challenges now faced. We expect that this review can provide a more comprehensive insight into the critical role of the JNK pathway in the pathogenesis of human diseases and hope that it also provides important clues for ameliorating disease conditions.
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Affiliation(s)
- Huaying Yan
- Department of Ultrasound, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China; (H.Y.); (L.H.)
| | - Lanfang He
- Department of Ultrasound, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China; (H.Y.); (L.H.)
| | - De Lv
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu 610075, China
| | - Jun Yang
- Cancer Center and State Key Laboratory of Biotherapy, Department of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China;
| | - Zhu Yuan
- Cancer Center and State Key Laboratory of Biotherapy, Department of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China;
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Aslam B, Hussain A, Faisal MN, Kousar S, Roobi A, Sajid MR, Gul A. Polyherbal extract improves glycometabolic control in alloxan-induced diabetic rats via down-regulating the MAPK/JNK pathway, modulating Nrf-2/Keap-1 expression, and stimulating insulin signaling. IRANIAN JOURNAL OF BASIC MEDICAL SCIENCES 2024; 27:170-179. [PMID: 38234664 PMCID: PMC10790299 DOI: 10.22038/ijbms.2023.72553.15780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 09/26/2023] [Indexed: 01/19/2024]
Abstract
Objectives This study focused on the evaluation of antioxidant and antidiabetic activities of polyherbal extract (PHE), containing Cassia absus (L.), Gymnema sylvestre (R. Br.), Nigella sativa (L.), and Piper nigrum (L.), in alloxan-induced diabetes model. Materials and Methods In vitro, HPLC characterization, DPPH scavenging assay, and α-amylase inhibition test were conducted. In vivo, acute oral toxicity of PHE was assessed. Alloxan-induced diabetic Wistar rats (n=6) were orally treated with PHE (200, 400, and 600 mg/kg/day) and glibenclamide (GLB; 10 mg/kg/day) for six consecutive weeks. Then, biochemical biomarkers, oxidative stress parameters, histopathological examination, and mRNA expression levels (RT-qPCR) were determined. Results The presence of polyphenols in PHE was confirmed in correlation to marked DPPH scavenging (IC50: 1.60 mg/ml) and α-amylase inhibition (IC50: 0.82 mg/ml). PHE demonstrated no toxicity in rats up to a dose of 2000 mg/kg. In diabetic rats, PHE dose-dependently ameliorated the serum levels of glucose, insulin, glycated hemoglobin A1c (HbA1c), leptin, and glucokinase (GCK). Also, PHE substantially alleviated serum inflammatory markers (TNF-α and CRP) and oxidative stress indicators (MDA, SOD, and CAT) in pancreatic tissues. PHE, particularly at 600 mg/kg, attenuated cellular oxidative stress via modulating the mRNA expression levels of genes regulating MAPK/JNK (Mapk-8, Traf-4, and Traf-6) and Nrf-2/Keap-1 pathways and promoted insulin signaling through up-regulating insulin signaling cascade (Pdx-1, Ins-1, and Ins-2), as compared to GLB. Furthermore, histopathological findings supported the aforementioned results. Conclusion Our study suggests that polyherbal extract has promising antioxidant and antidiabetic activities by modulating the MAPK/JNK, Nrf-2/Keap-1, and insulin signaling pathways.
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Affiliation(s)
- Bilal Aslam
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
| | - Asif Hussain
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
- Department of Pharmacy, Riphah International University, Faisalabad-38000, Faisalabad, Punjab, Pakistan
| | - Muhammad Naeem Faisal
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
| | - Shaneel Kousar
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
- Department of Pharmacology, Faculty of Pharmacy, University of Lahore-54590, Lahore, Punjab, Pakistan
| | - Alishbah Roobi
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
| | - Muhammad Rehan Sajid
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
| | - Aneela Gul
- Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad-38040, Faisalabad, Punjab, Pakistan
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(Flintoaca) Alexandru PR, Chiritoiu GN, Lixandru D, Zurac S, Ionescu-Targoviste C, Petrescu SM. EDEM1 regulates the insulin mRNA level by inhibiting the endoplasmic reticulum stress-induced IRE1/JNK/c-Jun pathway. iScience 2023; 26:107956. [PMID: 37822496 PMCID: PMC10562789 DOI: 10.1016/j.isci.2023.107956] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 07/22/2023] [Accepted: 09/14/2023] [Indexed: 10/13/2023] Open
Abstract
Pancreatic beta cells produce and secrete insulin as a response to rises in blood glucose. Despite the advances in understanding glucose-regulated insulin transcription and translation the mechanisms triggering the synthesis of new insulin molecules are still incompletely described. In this report, we identify EDEM1 as a new modulator of insulin synthesis and secretion. In the presence of EDEM1, INS-1E cells secrete significantly more insulin upon glucose stimulation compared to control cells. We found that overexpression of EDEM1 inhibited the IRE1/JNK/c-Jun pathway, leading to an increase in the insulin mRNA level. Similarly, EDEM1 transduced human islets secreted significantly more insulin upon stimulation. Furthermore, EDEM1 improved insulin secretion restoring normoglycemia and glucose tolerance in diabetic rats. We propose EDEM1 as a regulator of the UPR via IRE1/XBP1s and IRE1/JNK/c-Jun signaling cascades and insulin transcription in pancreatic β-cells, supporting EDEM1 as a potential target for the treatment of diabetes.
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Affiliation(s)
| | - Gabriela N. Chiritoiu
- Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, 060031 Bucharest, Romania
| | - Daniela Lixandru
- Department of Biochemistry, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Sabina Zurac
- Department of Physiology, “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | | | - Stefana M. Petrescu
- Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, 060031 Bucharest, Romania
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Kimani CN, Reuter H, Kotzé SH, Muller CJF. Regeneration of Pancreatic Beta Cells by Modulation of Molecular Targets Using Plant-Derived Compounds: Pharmacological Mechanisms and Clinical Potential. Curr Issues Mol Biol 2023; 45:6216-6245. [PMID: 37623211 PMCID: PMC10453321 DOI: 10.3390/cimb45080392] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/20/2023] [Accepted: 07/22/2023] [Indexed: 08/26/2023] Open
Abstract
Type 2 diabetes (T2D) is characterized by pancreatic beta-cell dysfunction, increased cell death and loss of beta-cell mass despite chronic treatment. Consequently, there has been growing interest in developing beta cell-centered therapies. Beta-cell regeneration is mediated by augmented beta-cell proliferation, transdifferentiation of other islet cell types to functional beta-like cells or the reprograming of beta-cell progenitors into fully differentiated beta cells. This mediation is orchestrated by beta-cell differentiation transcription factors and the regulation of the cell cycle machinery. This review investigates the beta-cell regenerative potential of antidiabetic plant extracts and phytochemicals. Various preclinical studies, including in vitro, in vivo and ex vivo studies, are highlighted. Further, the potential regenerative mechanisms and the intra and extracellular mediators that are of significance are discussed. Also, the potential of phytochemicals to translate into regenerative therapies for T2D patients is highlighted, and some suggestions regarding future perspectives are made.
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Affiliation(s)
- Clare Njoki Kimani
- Biomedical Research and Innovation Platform (BRIP), South African Medical Research Council (SAMRC), Cape Town 7505, South Africa;
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7505, South Africa
| | - Helmuth Reuter
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7505, South Africa
| | - Sanet Henriët Kotzé
- Division of Clinical Anatomy, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town 7505, South Africa
- Division of Anatomy, Department of Biomedical Sciences, School of Veterinary Medicine, Ross University, Basseterre P.O. Box 334, Saint Kitts and Nevis
| | - Christo John Fredrick Muller
- Biomedical Research and Innovation Platform (BRIP), South African Medical Research Council (SAMRC), Cape Town 7505, South Africa;
- Centre for Cardio-Metabolic Research in Africa, Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch 7600, South Africa
- Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa 3886, South Africa
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Aamir K, Sethi G, Afrin MR, Hossain CF, Jusuf PR, Sarker SD, Arya A. Arjunolic acid modulate pancreatic dysfunction by ameliorating pattern recognition receptor and canonical Wnt pathway activation in type 2 diabetic rats. Life Sci 2023:121856. [PMID: 37307966 DOI: 10.1016/j.lfs.2023.121856] [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: 03/30/2023] [Revised: 06/04/2023] [Accepted: 06/09/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND Arjunolic acid (AA) is a potent phytochemical with multiple therapeutics effects. In this study, AA is evaluated on type 2 diabetic (T2DM) rats to understand the mechanism of β-cell linkage with Toll-like receptor 4 (TLR-4) and canonical Wnt signaling. However, its role in modulating TLR-4 and canonical Wnt/β-catenin crosstalk on insulin signaling remains unclear during T2DM. Aim The current study is aimed to examine the potential role of AA on insulin signaling and TLR-4-Wnt crosstalk in the pancreas of type 2 diabetic rats. METHOD Multiple methods were used to determine molecular cognizance of AA in T2DM rats, when treated with different dosage levels. Histopathological and histomorphometry analysis was conducted using masson trichrome and H&E stains. While, protein and mRNA expressions of TLR-4/Wnt and insulin signaling were assessed using automated Western blotting (jess), immunohistochemistry, and RT-PCR. RESULTS Histopathological findings revealed that AA had reversed back the T2DM-induced apoptosis and necrosis caused to rats pancreas. Molecular findings exhibited prominent effects of AA in downregulating the elevated level of TLR-4, MyD88, NF-κB, p-JNK, and Wnt/β-catenin by blocking TLR-4/MyD88 and canonical Wnt signaling in diabetic pancreas, while IRS-1, PI3K, and pAkt were all upregulated by altering the NF-κB and β-catenin crosstalk during T2DM. CONCLUSION Overall results, indicate that AA has potential to develop as an effective therapeutic in the treatment of T2DM associated meta-inflammation. However, future preclinical research at multiple dose level in a long-term chronic T2DM disease model is warranted to understand its clinical relevance in cardiometabolic disease.
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Affiliation(s)
- Khurram Aamir
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia; Akhtar Saeed College of Pharmacy, Canal Campus, Lahore, Pakistan
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mst Rejina Afrin
- Department of Pharmacy, Faculty of Sciences and Engineering, East West University, Dhaka 1212, Bangladesh
| | - Chowdhury Faiz Hossain
- Department of Pharmacy, Faculty of Sciences and Engineering, East West University, Dhaka 1212, Bangladesh
| | - Patricia Regina Jusuf
- School of Biosciences, Faculty of Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Satyajit D Sarker
- Centre for Natural Product Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Aditya Arya
- School of Biosciences, Faculty of Sciences, University of Melbourne, Parkville, VIC, Australia; Centre for Natural Product Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, United Kingdom; Department of Pharmacology & Therapeutics, School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Malaysia.
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Saeed R, Mohammed AK, Saleh SE, Aboshanab KM, Aboulwafa MM, Taneera J. Expression Silencing of Mitogen-Activated Protein Kinase 8 Interacting Protein-1 Conferred Its Role in Pancreatic β-Cell Physiology and Insulin Secretion. Metabolites 2023; 13:metabo13020307. [PMID: 36837926 PMCID: PMC9964862 DOI: 10.3390/metabo13020307] [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: 01/13/2023] [Revised: 02/11/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Mitogen-activated protein kinase 8 interacting protein-1 (MAPK8IP1) gene has been recognized as a susceptibility gene for diabetes. However, its action in the physiology of pancreatic β-cells is not fully understood. Herein, bioinformatics and genetic analyses on the publicly available database were performed to map the expression of the MAPK8IP1 gene in human pancreatic islets and to explore whether this gene contains any genetic variants associated with type 2 diabetes (T2D). Moreover, a series of functional experiments were executed in a rat insulinoma cell line (INS-1 832/13) to investigate the role of the Mapk8ip1 gene in β-cell function. Metabolic engineering using RNA-sequencing (RNA-seq) data confirmed higher expression levels of MAPK8IP1 in human islets compared to other metabolic tissues. Additionally, comparable expression of MAPK8IP1 expression was detected in sorted human endocrine cells. However, β-cells exhibited higher expression of MAPK8IP1 than ductal and PSC cells. Notably, MAPK8IP1 expression was reduced in diabetic islets, and the expression was positively correlated with insulin and the β-cell transcription factor PDX1 and MAFA. Using the TIGER portal, we found that one genetic variant, "rs7115753," in the proximity of MAPK8IP1, passes the genome-wide significance for the association with T2D. Expression silencing of Mapk8ip1 by small interfering RNA (siRNA) in INS-1 cells reduced insulin secretion, glucose uptake rate, and reactive oxygen species (ROS) production. In contrast, insulin content, cell viability, and apoptosis without cytokines were unaffected. However, silencing of Mapk8ip1 reduced cytokines-induced apoptosis and downregulated the expression of several pancreatic β-cell functional markers including, Ins1, Ins2, Pdx1, MafA, Glut2, Gck, Insr, Vamp2, Syt5, and Cacna1a at mRNA and/or protein levels. Finally, we reported that siRNA silencing of Pdx1 resulted in the downregulation of MAPK8IP1 expression in INS-1 cells. In conclusion, our findings confirmed that MAPK8IP1 is an important component of pancreatic β-cell physiology and insulin secretion.
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Affiliation(s)
- Rania Saeed
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Abdul Khader Mohammed
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Sarra E. Saleh
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
| | - Khaled M. Aboshanab
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Correspondence: (K.M.A.); (J.T.); Tel.: +20-10075-82620 (K.M.A.); +971-6505-7743 (J.T.)
| | - Mohammad M. Aboulwafa
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Faculty of Pharmacy, King Salman International University, Ras-Sudr 46612, Egypt
| | - Jalal Taneera
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates
- Department of Basic Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Correspondence: (K.M.A.); (J.T.); Tel.: +20-10075-82620 (K.M.A.); +971-6505-7743 (J.T.)
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9
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Harithpriya K, Jayasuriya R, Adhikari T, Rai A, Ramkumar KM. Modulation of transcription factors by small molecules in β-cell development and differentiation. Eur J Pharmacol 2023; 946:175606. [PMID: 36809813 DOI: 10.1016/j.ejphar.2023.175606] [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: 11/12/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/21/2023]
Abstract
Transcription factors regulate gene expression and play crucial roles in development and differentiation of pancreatic β-cell. The expression and/or activities of these transcription factors are reduced when β-cells are chronically exposed to hyperglycemia, which results in loss of β-cell function. Optimal expression of such transcription factors is required to maintain normal pancreatic development and β-cell function. Over many other methods of regenerating β-cells, using small molecules to activate transcription factors has gained insights, resulting in β-cells regeneration and survival. In this review, we discuss the broad spectrum of transcription factors regulating pancreatic β-cell development, differentiation and regulation of these factors in normal and pathological states. Also, we have presented set of potential pharmacological effects of natural and synthetic compounds on activities of transcription factor involved in pancreatic β-cell regeneration and survival. Exploring these compounds and their action on transcription factors responsible for pancreatic β-cell function and survival could be useful in providing new insights for development of small molecule modulators.
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Affiliation(s)
- Kannan Harithpriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Ravichandran Jayasuriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Trishla Adhikari
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Awantika Rai
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India
| | - Kunka Mohanram Ramkumar
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur, 603 203, Tamil Nadu, India.
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Yudaeva AD, Stafeev IS, Michurina SS, Menshikov MY, Shestakova MV, Parfyonova YV. The interactions between inflammation and insulin resistance: molecular mechanisms in insulin-producing and insulin-dependent tissues. DIABETES MELLITUS 2023. [DOI: 10.14341/dm12981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
In the modern world the prevalence of obesity and type 2 diabetes mellitus (T2DM) significantly increases. In this light the risks of obesity-associated complications also grow up. The crucial linkage between obesity and its metabolic and cardiovascular complications is inflammatory process. The mechanism of this linkage is similar in pancreas and insulin-dependent tissues both on cells, cell-to-cell communication and signaling pathway levels: the catalysts are different lipids (cholesterol, free fatty acids, triglycerides), which are able to activate Toll-like receptors of innate immunity and inflammation. Nextly, IKK- and JNK-dependent cascades activate the secretion of inflammatory cytokines TNFa, IL-1b, IL-6 and others, which act by paracrine and autocrine manner and support inflammation both in local and systemic levels. Thus, insulin-producing and insulin-dependent tissues, which are involved in T2DM pathogenesis, through the inflammatory process integrate in pathogenic and self-maintaining cycle, which leads to the suppression of insulin secretion, pancreatic β-cell failure and the development of insulin-dependent tissues insulin resistance.
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Affiliation(s)
- A. D. Yudaeva
- National Medical Research Centre of Cardiology named after academician E.I.Chazov; Pirogov Russian National Research Medical University
| | - I. S. Stafeev
- National Medical Research Centre of Cardiology named after academician E.I.Chazov; Pirogov Russian National Research Medical University
| | - S. S. Michurina
- National Medical Research Centre of Cardiology named after academician E.I.Chazov; Lomonosov Moscow State University
| | - M. Yu. Menshikov
- National Medical Research Centre of Cardiology named after academician E.I.Chazov
| | | | - Y. V. Parfyonova
- National Medical Research Centre of Cardiology named after academician E.I.Chazov; Lomonosov Moscow State University
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11
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Surfactin Mitigates a High-Fat Diet and Streptozotocin-Induced Type 2 Diabetes through Improving Pancreatic Dysfunction and Inhibiting Inflammatory Response. Int J Mol Sci 2022; 23:ijms231911086. [PMID: 36232419 PMCID: PMC9570334 DOI: 10.3390/ijms231911086] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/10/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Surfactin from Bacillus amyloliquefaciens fmb50 was utilized to treat mice with type 2 diabetes (T2DM) induced by a high-fat diet/streptozotocin (HFD/STZ). Our group’s earlier research indicated that surfactin could lower blood glucose and mitigate liver dysfunction to further improve HFD/STZ-induced T2DM through modulating intestinal microbiota. Thus, we further investigated the effects of surfactin on the pancreas and colon in mice with T2DM to elucidate the detailed mechanism. In the present study, mice with HFD/STZ-induced T2DM had their pancreatic and colon inflammation, oxidative stress, and endoplasmic reticulum stress (ERS) reduced when given oral surfactin at a dose of 80 mg/kg body weight. According to further research, surfactin also improved glucose metabolism by activating the phosphatidylinositol kinase (PI3K)/protein kinase B (Akt) signaling pathway, further protecting islets β-cell, promoting insulin secretion, inhibiting glucagon release and mitigating pancreas dysfunction. Additionally, after surfactin treatment, the colon levels of the tight junction proteins Occludin and Claudin-1 of T2DM mice were considerably increased by 130.64% and by 36.40%, respectively. These findings revealed that surfactin not only ameliorated HFD/STZ-induced pancreas inflammation and dysfunction and preserved intestinal barrier dysfunction and gut microbiota homeostasis but also enhanced insulin sensitivity and glucose homeostasis in T2DM mice. Finally, in the further experiment, we were able to demonstrate that early surfactin intervention might delay the development of T2DM caused by HFD/STZ, according to critical biochemical parameters in serum.
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Chekol Abebe E, Tilahun Muche Z, Behaile T/Mariam A, Mengie Ayele T, Mekonnen Agidew M, Teshome Azezew M, Abebe Zewde E, Asmamaw Dejenie T, Asmamaw Mengstie M. The structure, biosynthesis, and biological roles of fetuin-A: A review. Front Cell Dev Biol 2022; 10:945287. [PMID: 35923855 PMCID: PMC9340150 DOI: 10.3389/fcell.2022.945287] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/28/2022] [Indexed: 11/21/2022] Open
Abstract
Fetuin-A is a heterodimeric plasma glycoprotein containing an A-chain of 282 amino acids and a B-chain of 27 amino acid residues linked by a single inter-disulfide bond. It is predominantly expressed in embryonic cells and adult hepatocytes, and to a lesser extent in adipocytes and monocytes. Fetuin-A binds with a plethora of receptors and exhibits multifaceted physiological and pathological functions. It is involved in the regulation of calcium metabolism, osteogenesis, and the insulin signaling pathway. It also acts as an ectopic calcification inhibitor, protease inhibitor, inflammatory mediator, anti-inflammatory partner, atherogenic factor, and adipogenic factor, among other several moonlighting functions. Fetuin-A has also been demonstrated to play a crucial role in the pathogenesis of several disorders. This review mainly focuses on the structure, synthesis, and biological roles of fetuin-A. Information was gathered manually from various journals via electronic searches using PubMed, Google Scholar, HINARI, and Cochrane Library from inception to 2022. Studies written in English and cohort, case-control, cross-sectional, or experimental studies were considered in the review, otherwise excluded.
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Affiliation(s)
- Endeshaw Chekol Abebe
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Zelalem Tilahun Muche
- Department of Physiology, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Awigchew Behaile T/Mariam
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Teklie Mengie Ayele
- Department of Pharmacy, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Melaku Mekonnen Agidew
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Muluken Teshome Azezew
- Department of Physiology, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Edgeit Abebe Zewde
- Department of Physiology, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
| | - Tadesse Asmamaw Dejenie
- Department of Medical Biochemistry, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Misganaw Asmamaw Mengstie
- Department of Medical Biochemistry, College of Health Sciences, Debre Tabor University, Debre Tabor, Ethiopia
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Langlois A, Dumond A, Vion J, Pinget M, Bouzakri K. Crosstalk Communications Between Islets Cells and Insulin Target Tissue: The Hidden Face of Iceberg. Front Endocrinol (Lausanne) 2022; 13:836344. [PMID: 35185804 PMCID: PMC8851682 DOI: 10.3389/fendo.2022.836344] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/06/2022] [Indexed: 12/11/2022] Open
Abstract
The regulation of insulin secretion is under control of a complex inter-organ/cells crosstalk involving various metabolites and/or physical connections. In this review, we try to illustrate with current knowledge how β-cells communicate with other cell types and organs in physiological and pathological contexts. Moreover, this review will provide a better understanding of the microenvironment and of the context in which β-cells exist and how this can influence their survival and function. Recent studies showed that β-cell insulin secretion is regulated also by a direct and indirect inter-organ/inter-cellular communication involving various factors, illustrating the idea of "the hidden face of the iceberg". Moreover, any disruption on the physiological communication between β-cells and other cells or organs can participate on diabetes onset. Therefore, for new anti-diabetic treatments' development, it is necessary to consider the entire network of cells and organs involved in the regulation of β-cellular function and no longer just β-cell or pancreatic islet alone. In this context, we discuss here the intra-islet communication, the β-cell/skeletal muscle, β-cell/adipose tissue and β-cell/liver cross talk.
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Jaikumkao K, Promsan S, Thongnak L, Swe MT, Tapanya M, Htun KT, Kothan S, Intachai N, Lungkaphin A. Dapagliflozin ameliorates pancreatic injury and activates kidney autophagy by modulating the AMPK/mTOR signaling pathway in obese rats. J Cell Physiol 2021; 236:6424-6440. [PMID: 33559163 DOI: 10.1002/jcp.30316] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/30/2020] [Accepted: 01/27/2021] [Indexed: 02/05/2023]
Abstract
Chronic consumption of a high-fat diet induces obesity and impairs the ultra-structure of organs and tissues. We examined the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor-dapagliflozin on renal and pancreatic injuries in obese condition. Rats were fed a high-fat diet for 16 weeks to induce obesity. After that, dapagliflozin or vildagliptin, 1.0 or 3.0 mg/kg/day, respectively, was administered by oral gavage for 4 weeks. The effects of dapagliflozin on insulin resistance, kidney autophagy, pancreatic oxidative stress, endoplasmic reticulum (ER) stress, inflammation, and apoptosis in high-fat diet-induced obese rats were elucidated. High-fat-diet fed rats demonstrated metabolic abnormalities including increased body weight, visceral fat weight, plasma insulin, plasma cholesterol, homeostasis model assessment (HOMA) index, and TAUCg, indicating the obese-insulin resistant and glucose intolerance conditions. Also, high-fat-diet fed rats exhibited significant pancreatic injury accompanied by decreased kidney autophagy. Dapagliflozin or vildagliptin treatment for 4 weeks ameliorated pancreatic oxidative stress, ER stress, inflammation, and apoptosis and restored kidney autophagy in obese rats. Moreover, the morphology changes of the pancreas and kidney were improved in the treated groups. Interestingly, dapagliflozin showed higher efficacy than vildagliptin in improving body weight, visceral fat weight, plasma cholesterol level, and pancreatic oxidative stress in our model. Taken together, the present study demonstrated that the therapeutic effects of dapagliflozin attenuated pancreatic injury, pancreatic oxidative stress, ER stress, inflammation, apoptosis, and exerted renoprotective effects by restoring autophagic signaling in obese rats.
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Affiliation(s)
- Krit Jaikumkao
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Center of Radiation Research and Medical Imaging, Chiang Mai University, Chiang Mai, Thailand
| | - Sasivimon Promsan
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Laongdao Thongnak
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Myat T Swe
- Department of Physiology, University of Medicine 2, Yangon, Yangon, Myanmar
| | - Monruedee Tapanya
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Khin T Htun
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Suchart Kothan
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Center of Radiation Research and Medical Imaging, Chiang Mai University, Chiang Mai, Thailand
| | - Nuttawadee Intachai
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Anusorn Lungkaphin
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
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Backes TM, Langfermann DS, Lesch A, Rössler OG, Laschke MW, Vinson C, Thiel G. Regulation and function of AP-1 in insulinoma cells and pancreatic β-cells. Biochem Pharmacol 2021; 193:114748. [PMID: 34461116 DOI: 10.1016/j.bcp.2021.114748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 12/16/2022]
Abstract
Cav1.2 L-type voltage-gated Ca2+ channels play a central role in pancreatic β-cells by integrating extracellular signals with intracellular signaling events leading to insulin secretion and altered gene transcription. Here, we investigated the intracellular signaling pathway following stimulation of Cav1.2 Ca2+ channels and addressed the function of the transcription factor activator protein-1 (AP-1) in pancreatic β-cells of transgenic mice. Stimulation of Cav1.2 Ca2+ channels activates AP-1 in insulinoma cells. Pharmacological and genetic experiments identified c-Jun N-terminal protein kinase as a signal transducer connecting Cav1.2 Ca2+ channel activation with gene transcription. Moreover, the basic region-leucine zipper proteins ATF2 and c-Jun or c-Jun-related proteins were involved in stimulus-transcription coupling. We addressed the functions of AP-1 in pancreatic β-cells analyzing a newly generated transgenic mouse model. These transgenic mice expressed A-Fos, a mutant of c-Fos that attenuates DNA binding of c-Fos dimerization partners. In insulinoma cells, A-Fos completely blocked AP-1 activation following stimulation of Cav1.2 Ca2+ channels. The analysis of transgenic A-Fos-expressing mice revealed that the animals displayed impaired glucose tolerance. Thus, we show here for the first time that AP-1 controls an important function of pancreatic β-cells in vivo, the regulation of glucose homeostasis.
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Affiliation(s)
- Tobias M Backes
- Saarland University Medical Faculty, Department of Medical Biochemistry and Molecular Biology, D-66421 Homburg, Germany
| | - Daniel S Langfermann
- Saarland University Medical Faculty, Department of Medical Biochemistry and Molecular Biology, D-66421 Homburg, Germany
| | - Andrea Lesch
- Saarland University Medical Faculty, Department of Medical Biochemistry and Molecular Biology, D-66421 Homburg, Germany
| | - Oliver G Rössler
- Saarland University Medical Faculty, Department of Medical Biochemistry and Molecular Biology, D-66421 Homburg, Germany
| | - Matthias W Laschke
- Saarland University Medical Faculty, Institute for Clinical and Experimental Surgery, D-66421 Homburg, Germany
| | | | - Gerald Thiel
- Saarland University Medical Faculty, Department of Medical Biochemistry and Molecular Biology, D-66421 Homburg, Germany.
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Šrámek J, Němcová-Fürstová V, Kovář J. Molecular Mechanisms of Apoptosis Induction and Its Regulation by Fatty Acids in Pancreatic β-Cells. Int J Mol Sci 2021; 22:4285. [PMID: 33924206 PMCID: PMC8074590 DOI: 10.3390/ijms22084285] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/09/2021] [Accepted: 04/16/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cell failure and death contribute significantly to the pathogenesis of type 2 diabetes. One of the main factors responsible for β-cell dysfunction and subsequent cell death is chronic exposure to increased concentrations of FAs (fatty acids). The effect of FAs seems to depend particularly on the degree of their saturation. Saturated FAs induce apoptosis in pancreatic β-cells, whereas unsaturated FAs are well tolerated and are even capable of inhibiting the pro-apoptotic effect of saturated FAs. Molecular mechanisms of apoptosis induction by saturated FAs in β-cells are not completely elucidated. Saturated FAs induce ER stress, which in turn leads to activation of all ER stress pathways. When ER stress is severe or prolonged, apoptosis is induced. The main mediator seems to be the CHOP transcription factor. Via regulation of expression/activity of pro- and anti-apoptotic Bcl-2 family members, and potentially also through the increase in ROS production, CHOP switches on the mitochondrial pathway of apoptosis induction. ER stress signalling also possibly leads to autophagy signalling, which may activate caspase-8. Saturated FAs activate or inhibit various signalling pathways, i.e., p38 MAPK signalling, ERK signalling, ceramide signalling, Akt signalling and PKCδ signalling. This may lead to the activation of the mitochondrial pathway of apoptosis, as well. Particularly, the inhibition of the pro-survival Akt signalling seems to play an important role. This inhibition may be mediated by multiple pathways (e.g., ER stress signalling, PKCδ and ceramide) and could also consequence in autophagy signalling. Experimental evidence indicates the involvement of certain miRNAs in mechanisms of FA-induced β-cell apoptosis, as well. In the rather rare situations when unsaturated FAs are also shown to be pro-apoptotic, the mechanisms mediating this effect in β-cells seem to be the same as for saturated FAs. To conclude, FA-induced apoptosis rather appears to be preceded by complex cross talks of multiple signalling pathways. Some of these pathways may be regulated by decreased membrane fluidity due to saturated FA incorporation. Few data are available concerning molecular mechanisms mediating the protective effect of unsaturated FAs on the effect of saturated FAs. It seems that the main possible mechanism represents a rather inhibitory intervention into saturated FA-induced pro-apoptotic signalling than activation of some pro-survival signalling pathway(s) or metabolic interference in β-cells. This inhibitory intervention may be due to an increase of membrane fluidity.
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Affiliation(s)
- Jan Šrámek
- Department of Biochemistry, Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague, Czech Republic;
| | - Vlasta Němcová-Fürstová
- Department of Biochemistry, Cell and Molecular Biology & Center for Research of Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University, Ruská 87, 100 00 Prague, Czech Republic;
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Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling. Int J Mol Sci 2021; 22:ijms22073351. [PMID: 33805912 PMCID: PMC8037903 DOI: 10.3390/ijms22073351] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 12/21/2022] Open
Abstract
The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.
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Mazzoli A, Sardi C, Breasson L, Theilig F, Becattini B, Solinas G. JNK1 ablation improves pancreatic β-cell mass and function in db/db diabetic mice without affecting insulin sensitivity and adipose tissue inflammation. FASEB Bioadv 2021; 3:94-107. [PMID: 33615154 PMCID: PMC7876705 DOI: 10.1096/fba.2020-00081] [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: 08/27/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 12/15/2022] Open
Abstract
The cJun N‐terminal Kinases (JNK) emerged as a major link between obesity and insulin resistance, but their role in the loss of pancreatic β‐cell mass and function driving the progression from insulin resistance to type‐2 diabetes and in the complications of diabetes was not investigated to the same extent. Furthermore, it was shown that pan‐JNK inhibition exacerbates kidney damage in the db/db model of obesity‐driven diabetes. Here we investigate the role of JNK1 in the db/db model of obesity‐driven type‐2 diabetes. Mice with systemic ablation of JNK1 (JNK1−/−) were backcrossed for more than 10 generations in db/+ C57BL/KS mice to generate db/db‐JNK1−/− mice and db/db control mice. To define the role of JNK1 in the loss of β‐cell mass and function occurring during obesity‐driven diabetes we performed comprehensive metabolic phenotyping, evaluated steatosis and metabolic inflammation, performed morphometric and cellular composition analysis of pancreatic islets, and evaluated kidney function in db/db‐JNK1−/− mice and db/db controls. db/db‐JNK1−/− mice and db/db control mice developed insulin resistance, fatty liver, and metabolic inflammation to a similar extent. However, db/db‐JNK1−/− mice displayed better glucose tolerance and improved insulin levels during glucose tolerance test, higher pancreatic insulin content, and larger pancreatic islets with more β‐cells than db/db mice. Finally, albuminuria, kidney histopathology, kidney inflammation and oxidative stress in db/db‐JNK1−/− mice and in db/db mice were similar. Our data indicate that selective JNK1 ablation improves glucose tolerance in db/db mice by reducing the loss of functional β‐cells occurring in the db/db mouse model of obesity‐driven diabetes, without significantly affecting metabolic inflammation, steatosis, and insulin sensitivity. Furthermore, we have found that, differently from what previously reported for pan‐JNK inhibitors, selective JNK1 ablation does not exacerbate kidney dysfunction in db/db mice. We conclude that selective JNK1 inactivation may have a superior therapeutic index than pan‐JNK inhibition in obesity‐driven diabetes.
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Affiliation(s)
- Arianna Mazzoli
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Claudia Sardi
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Ludovic Breasson
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Franziska Theilig
- Institute of Anatomy Christian Albrechts-University Kiel Kiel Germany
| | - Barbara Becattini
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
| | - Giovanni Solinas
- The Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research Department of Molecular and Clinical Medicine Institute of Medicine University of Gothenburg Gothenburg Sweden
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Eguchi N, Vaziri ND, Dafoe DC, Ichii H. The Role of Oxidative Stress in Pancreatic β Cell Dysfunction in Diabetes. Int J Mol Sci 2021; 22:ijms22041509. [PMID: 33546200 PMCID: PMC7913369 DOI: 10.3390/ijms22041509] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 02/07/2023] Open
Abstract
Diabetes is a chronic metabolic disorder characterized by inappropriately elevated glucose levels as a result of impaired pancreatic β cell function and insulin resistance. Extensive studies have been conducted to elucidate the mechanism involved in the development of β cell failure and death under diabetic conditions such as hyperglycemia, hyperlipidemia, and inflammation. Of the plethora of proposed mechanisms, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and oxidative stress have been shown to play a central role in promoting β cell dysfunction. It has become more evident in recent years that these 3 factors are closely interrelated and importantly aggravate each other. Oxidative stress in particular is of great interest to β cell health and survival as it has been shown that β cells exhibit lower antioxidative capacity. Therefore, this review will focus on discussing factors that contribute to the development of oxidative stress in pancreatic β cells and explore the downstream effects of oxidative stress on β cell function and health. Furthermore, antioxidative capacity of β cells to counteract these effects will be discussed along with new approaches focused on preserving β cells under oxidative conditions.
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Affiliation(s)
- Natsuki Eguchi
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
| | | | - Donald C. Dafoe
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
| | - Hirohito Ichii
- Department of Surgery, University of California, Irvine, CA 92697, USA; (N.E.); (D.C.D.)
- Correspondence: ; Tel.: +1-714-456-8590
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Engin AB, Engin A. Protein Kinases Signaling in Pancreatic Beta-cells Death and Type 2 Diabetes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:195-227. [PMID: 33539017 DOI: 10.1007/978-3-030-49844-3_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Type 2 diabetes (T2D) is a worldwide serious public health problem. Insulin resistance and β-cell failure are the two major components of T2D pathology. In addition to defective endoplasmic reticulum (ER) stress signaling due to glucolipotoxicity, β-cell dysfunction or β-cell death initiates the deleterious vicious cycle observed in T2D. Although the primary cause is still unknown, overnutrition that contributes to the induction of the state of low-grade inflammation, and the activation of various protein kinases-related metabolic pathways are main factors leading to T2D. In this chapter following subjects, which have critical checkpoints regarding β-cell fate and protein kinases pathways are discussed; hyperglycemia-induced β-cell failure, chronic accumulation of unfolded protein in β-cells, the effect of intracellular reactive oxygen species (ROS) signaling to insulin secretion, excessive saturated free fatty acid-induced β-cell apoptosis, mitophagy dysfunction, proinflammatory responses and insulin resistance, and the reprogramming of β-cell for differentiation or dedifferentiation in T2D. There is much debate about selecting proposed therapeutic strategies to maintain or enhance optimal β-cell viability for adequate insulin secretion in T2D. However, in order to achieve an effective solution in the treatment of T2D, more intensive clinical trials are required on newer therapeutic options based on protein kinases signaling pathways.
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Affiliation(s)
- Ayse Basak Engin
- Department of Toxicology, Faculty of Pharmacy, Gazi University, Ankara, Turkey.
| | - Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey
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Abstract
Obesity is a health condition that has reached pandemic levels and is implicated in the development and progression of type 2 diabetes mellitus, cancer and heart failure. A key characteristic of obesity is the activation of stress-activated protein kinases (SAPKs), such as the p38 and JNK stress kinases, in several organs, including adipose tissue, liver, skeletal muscle, immune organs and the central nervous system. The correct timing, intensity and duration of SAPK activation contributes to cellular metabolic adaptation. By contrast, uncontrolled SAPK activation has been proposed to contribute to the complications of obesity. The stress kinase signalling pathways have therefore been identified as potential targets for the development of novel therapeutic approaches for metabolic syndrome. The past few decades have seen intense research efforts to determine how these kinases are regulated in a cell-specific manner and to define their contribution to the development of obesity and insulin resistance. Several studies have uncovered new and unexpected functions of the non-classical members of both pathways. Here, we provide an overview of the role of SAPKs in metabolic control and highlight important discoveries in the field.
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Affiliation(s)
- Ivana Nikolic
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Magdalena Leiva
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Guadalupe Sabio
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain.
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Hoevenaar M, Goossens D, Roorda J. Angiotensin-converting enzyme 2, the complement system, the kallikrein-kinin system, type-2 diabetes, interleukin-6, and their interactions regarding the complex COVID-19 pathophysiological crossroads. J Renin Angiotensin Aldosterone Syst 2020; 21:1470320320979097. [PMID: 33283602 PMCID: PMC7724427 DOI: 10.1177/1470320320979097] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022] Open
Abstract
Because of the current COVID-19-pandemic, the world is currently being held hostage in various lockdowns. ACE2 facilitates SARS-CoV-2 cell-entry, and is at the very center of several pathophysiological pathways regarding the RAAS, CS, KKS, T2DM, and IL-6. Their interactions with severe COVID-19 complications (e.g. ARDS and thrombosis), and potential therapeutic targets for pharmacological intervention, will be reviewed.
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Affiliation(s)
| | | | - Janne Roorda
- Medical Doctor, General Practice
van Dijk, Oisterwijk, The Netherlands
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β-Cell specific transcription factors in the context of diabetes mellitus and β-cell regeneration. Mech Dev 2020; 163:103634. [PMID: 32711047 DOI: 10.1016/j.mod.2020.103634] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/15/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023]
Abstract
All pancreatic cell populations arise from the standard gut endoderm layer in developing embryos, requiring a regulatory gene network to originate and maintain endocrine lineages and endocrine function. The pancreatic organogenesis is regulated by the temporal expression of transcription factors and plays a diverse role in the specification, development, differentiation, maturation, and functional maintenance. Altered expression and activity of these transcription factors are often associated with diabetes mellitus. Recent advancements in the stem cells and invitro derived islets to treat diabetes mellitus has attracted a great deal of interest in the understanding of factors regulating the development, differentiation, and functions of islets including transcription factors. This review discusses the myriad of transcription factors regulating the development of the pancreas, differentiation of β-islets, and how these factors regulated in normal and disease states. Exploring these factors in such critical context and exogenous or endogenous expression of development and differentiation-specific transcription factors with improved epigenetic plasticity/signaling axis in diabetic milieu would useful for the development of β-cells from other cell sources.
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Evans LW, Stratton MS, Ferguson BS. Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease. Nat Prod Rep 2020; 37:653-676. [PMID: 31993614 PMCID: PMC7577396 DOI: 10.1039/c9np00057g] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.
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Affiliation(s)
- Levi W Evans
- Department of Nutrition, University of Nevada, Reno, NV 89557, USA.
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Role of c-Jun N-terminal Kinase (JNK) in Obesity and Type 2 Diabetes. Cells 2020; 9:cells9030706. [PMID: 32183037 PMCID: PMC7140703 DOI: 10.3390/cells9030706] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/16/2020] [Accepted: 03/11/2020] [Indexed: 12/13/2022] Open
Abstract
Obesity has been described as a global epidemic and is a low-grade chronic inflammatory disease that arises as a consequence of energy imbalance. Obesity increases the risk of type 2 diabetes (T2D), by mechanisms that are not entirely clarified. Elevated circulating pro-inflammatory cytokines and free fatty acids (FFA) during obesity cause insulin resistance and ß-cell dysfunction, the two main features of T2D, which are both aggravated with the progressive development of hyperglycemia. The inflammatory kinase c-jun N-terminal kinase (JNK) responds to various cellular stress signals activated by cytokines, free fatty acids and hyperglycemia, and is a key mediator in the transition between obesity and T2D. Specifically, JNK mediates both insulin resistance and ß-cell dysfunction, and is therefore a potential target for T2D therapy.
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Obesity: Pathophysiology, monosodium glutamate-induced model and anti-obesity medicinal plants. Biomed Pharmacother 2019; 111:503-516. [DOI: 10.1016/j.biopha.2018.12.108] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 12/13/2018] [Accepted: 12/23/2018] [Indexed: 02/08/2023] Open
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Kim TH, Yang YM, Han CY, Koo JH, Oh H, Kim SS, You BH, Choi YH, Park TS, Lee CH, Kurose H, Noureddin M, Seki E, Wan YJY, Choi CS, Kim SG. Gα12 ablation exacerbates liver steatosis and obesity by suppressing USP22/SIRT1-regulated mitochondrial respiration. J Clin Invest 2018; 128:5587-5602. [PMID: 30300140 DOI: 10.1172/jci97831] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/02/2018] [Indexed: 12/20/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) arises from mitochondrial dysfunction under sustained imbalance between energy intake and expenditure, but the underlying mechanisms controlling mitochondrial respiration have not been entirely understood. Heterotrimeric G proteins converge with activated GPCRs to modulate cell-signaling pathways to maintain metabolic homeostasis. Here, we investigated the regulatory role of G protein α12 (Gα12) on hepatic lipid metabolism and whole-body energy expenditure in mice. Fasting increased Gα12 levels in mouse liver. Gα12 ablation markedly augmented fasting-induced hepatic fat accumulation. cDNA microarray analysis from Gna12-KO liver revealed that the Gα12-signaling pathway regulated sirtuin 1 (SIRT1) and PPARα, which are responsible for mitochondrial respiration. Defective induction of SIRT1 upon fasting was observed in the liver of Gna12-KO mice, which was reversed by lentivirus-mediated Gα12 overexpression in hepatocytes. Mechanistically, Gα12 stabilized SIRT1 protein through transcriptional induction of ubiquitin-specific peptidase 22 (USP22) via HIF-1α increase. Gα12 levels were markedly diminished in liver biopsies from NAFLD patients. Consistently, Gna12-KO mice fed a high-fat diet displayed greater susceptibility to diet-induced liver steatosis and obesity due to decrease in energy expenditure. Our results demonstrate that Gα12 regulates SIRT1-dependent mitochondrial respiration through HIF-1α-dependent USP22 induction, identifying Gα12 as an upstream molecule that contributes to the regulation of mitochondrial energy expenditure.
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Affiliation(s)
- Tae Hyun Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
| | - Yoon Mee Yang
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea.,Division of Digestive and Liver Diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Chang Yeob Han
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea.,Department of Pharmacology, School of Medicine, Wonkwang University, Iksan, Jeonbuk, South Korea
| | - Ja Hyun Koo
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
| | - Hyunhee Oh
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, South Korea
| | - Su Sung Kim
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, South Korea
| | - Byoung Hoon You
- College of Pharmacy, Dongguk University, Ilsan Dong-Gu, Goyang, Gyeoggi-Do, South Korea
| | - Young Hee Choi
- College of Pharmacy, Dongguk University, Ilsan Dong-Gu, Goyang, Gyeoggi-Do, South Korea
| | - Tae-Sik Park
- Department of Life Science, Gachon University, Seongnam, Gyeonggi-Do, South Korea
| | - Chang Ho Lee
- College of Medicine, Hanyang University, Seoul, South Korea
| | - Hitoshi Kurose
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Mazen Noureddin
- Fatty Liver Disease Program, Division of Digestive and Liver Diseases, Department of Medicine, Comprehensive Transplant Center, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Ekihiro Seki
- Division of Digestive and Liver Diseases, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Yu-Jui Yvonne Wan
- Department of Medical Pathology and Laboratory Medicine, UCD, Sacramento, California, USA
| | - Cheol Soo Choi
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, Incheon, South Korea.,Endocrinology, Internal Medicine, Gachon University Gil Medical Center, Incheon, South Korea
| | - Sang Geon Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
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Langfermann DS, Rössler OG, Thiel G. Stimulation of B-Raf increases c-Jun and c-Fos expression and upregulates AP-1-regulated gene transcription in insulinoma cells. Mol Cell Endocrinol 2018; 472:126-139. [PMID: 29225069 DOI: 10.1016/j.mce.2017.12.003] [Citation(s) in RCA: 12] [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: 07/08/2017] [Revised: 12/05/2017] [Accepted: 12/07/2017] [Indexed: 01/15/2023]
Abstract
Stimulation of pancreatic β-cells with glucose activates the protein kinases B-Raf and extracellular signal-regulated protein kinase that participate in glucose sensing. Inhibition of both kinases results in impairment of glucose-regulated gene transcription. To analyze the signaling pathway controlled by B-Raf, we expressed a conditionally active form of B-Raf in INS-1 insulinoma cells. Here, we show that stimulation of B-Raf strongly activated the transcription factor AP-1 which is accompanied by increased c-Jun and c-Fos promoter activities, an upregulation of c-Jun and c-Fos biosynthesis, and elevated transcriptional activation potentials of c-Jun and c-Fos. Mutational analysis identified the AP-1 sites within the c-Jun promoter and the serum response element (SRE) within the c-Fos promoter as the essential genetic elements connecting B-Raf stimulation with AP-1 activation. In line with this, the transcriptional activation potential of the SRE-binding protein Elk-1 was increased following B-Raf activation. The signal pathway from B-Raf to AP-1 required the activation of c-Jun. We identified the cyclin D1 gene as a delayed response gene for AP-1 following stimulation of B-Raf in insulinoma cells. Moreover, MAP kinase phosphatase-1 and the Ca2+/calmodulin-dependent protein phosphatase calcineurin were identified to function as shut-off-devices for the signaling cascade connecting B-Raf stimulation with the activation of AP-1. The fact that stimulation with glucose, activation of L-type voltage-gated Ca2+ channels, and stimulation of B-Raf all trigger an activation of AP-1 indicates that AP-1 is a point of convergence of signaling pathways in β-cell.
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Affiliation(s)
- Daniel S Langfermann
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany
| | - Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Saarland University Medical Faculty, D-66421 Homburg, Germany.
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Gerst F, Wagner R, Kaiser G, Panse M, Heni M, Machann J, Bongers MN, Sartorius T, Sipos B, Fend F, Thiel C, Nadalin S, Königsrainer A, Stefan N, Fritsche A, Häring HU, Ullrich S, Siegel-Axel D. Metabolic crosstalk between fatty pancreas and fatty liver: effects on local inflammation and insulin secretion. Diabetologia 2017; 60:2240-2251. [PMID: 28791439 DOI: 10.1007/s00125-017-4385-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 06/15/2017] [Indexed: 01/29/2023]
Abstract
AIMS/HYPOTHESIS Obesity-linked ectopic fat accumulation is associated with the development of type 2 diabetes. Whether pancreatic and liver steatosis impairs insulin secretion is controversial. We examined the crosstalk of human pancreatic fat cells with islets and the role of diabetogenic factors, i.e. palmitate and fetuin-A, a hepatokine released from fatty liver. METHODS Human pancreatic resections were immunohistochemically stained for insulin, glucagon, somatostatin and the macrophage/monocyte marker CD68. Pancreatic adipocytes were identified by Oil Red O and adiponectin staining. Primary pancreatic pre-adipocytes and differentiated adipocytes were co-cultured with human islets isolated from organ donors and the metabolic crosstalk between fatty liver and fatty pancreas was mimicked by the addition of palmitate and fetuin-A. Insulin secretion was evaluated by ELISA and RIA. Cytokine expression and secretion were assessed by RT-PCR and multiplex assay, respectively. Subcellular distribution of proteins was examined by confocal microscopy and protein phosphorylation by western blotting. RESULTS In human pancreatic parenchyma, highly differentiated adipocytes were detected in the proximity of islets with normal architecture and hormone distribution. Infiltration of adipocytes was associated with an increased number of CD68-positive cells within islets. In isolated primary pancreatic pre-adipocytes and differentiated adipocytes, palmitate and fetuin-A induced IL6, CXCL8 and CCL2 mRNA expression. Cytokine production was toll-like receptor 4 (TLR4)-dependent and further accentuated in pre-adipocytes when co-cultured with islets. In islets, IL6 and CXCL8 mRNA levels were also increased by fetuin-A and palmitate. Only in macrophages within the isolated islets, palmitate and fetuin-A stimulated the production of the cytotoxic cytokine IL-1β. Palmitate, but not fetuin-A, exerted pro-apoptotic effects in islet cells. Instead, fetuin-A impaired glucose-induced insulin secretion in a TLR4-independent, but c-Jun N-terminal kinase- and Ca2+-dependent, manner. CONCLUSIONS/INTERPRETATION These results provide the first evidence that fetuin-A-mediated metabolic crosstalk of fatty liver with islets may contribute to obesity-linked glucose blindness of beta cells, while fatty pancreas may exacerbate local inflammation.
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Affiliation(s)
- Felicia Gerst
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany.
- German Center for Diabetes Research (DZD), Tuebingen, Germany.
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany.
| | - Robert Wagner
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Gabriele Kaiser
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Madhura Panse
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Martin Heni
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Jürgen Machann
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Tuebingen, Germany
| | - Malte N Bongers
- Section of Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital Tuebingen, Tuebingen, Germany
| | - Tina Sartorius
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Bence Sipos
- Department of General Pathology and Pathological Anatomy, University Hospital Tuebingen, Tuebingen, Germany
| | - Falko Fend
- Department of General Pathology and Pathological Anatomy, University Hospital Tuebingen, Tuebingen, Germany
| | - Christian Thiel
- Department of General, Visceral and Transplant Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Silvio Nadalin
- Department of General, Visceral and Transplant Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Alfred Königsrainer
- Department of General, Visceral and Transplant Surgery, University Hospital Tuebingen, Tuebingen, Germany
| | - Norbert Stefan
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Andreas Fritsche
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Susanne Ullrich
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
| | - Dorothea Siegel-Axel
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the Eberhard Karls University of Tuebingen (IDM), Tuebingen, Germany
- German Center for Diabetes Research (DZD), Tuebingen, Germany
- Department of Internal Medicine IV, University Hospital Tuebingen, Otfried-Mueller Street 10, 72076, Tuebingen, Germany
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Chen Z, Yu R, Xiong Y, Du F, Zhu S. A vicious circle between insulin resistance and inflammation in nonalcoholic fatty liver disease. Lipids Health Dis 2017; 16:203. [PMID: 29037210 PMCID: PMC5644081 DOI: 10.1186/s12944-017-0572-9] [Citation(s) in RCA: 188] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/20/2017] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of diseases, including simple steatosis, nonalcoholic steatohepatitis (NASH), liver cirrhosis and hepatocellular carcinoma. Lipotoxicity, insulin resistance (IR) and inflammation are involved in the disease process. Lipotoxicity promotes inflammation and IR, which in turn, increase adipocyte lipolysis and exacerbates lipotoxicity. Furthermore, IR and inflammation form a vicious circle, with each condition promoting the other and accelerating the development of NAFLD in the presence of lipotoxicity. As an integrator of inflammatory pathway networks, nuclear factor-kappa B (NF-κB) regulates expression of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and anti-inflammatory cytokines, such as adiponectin in NAFLD. In this review, the relationships between lipotoxicity, IR and inflammation in NAFLD are discussed, with particular emphasis on the inflammatory pathways.
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Affiliation(s)
- Zhonge Chen
- Medical Center of The Graduate School, Nanchang University, Nanchang, China
| | - Rong Yu
- Department of Endocrinology, Second Affliated Hospital, Nanchang University, Nanchang, China
| | - Ying Xiong
- Department of Gastroenterology, Second Affliated Hospital, Nanchang University, No. 1, Minde Road, Nanchang, 330006, China
| | - Fangteng Du
- Department of Gastroenterology, Second Affliated Hospital, Nanchang University, No. 1, Minde Road, Nanchang, 330006, China.
| | - Shuishan Zhu
- Department of Gastroenterology, Second Affliated Hospital, Nanchang University, No. 1, Minde Road, Nanchang, 330006, China.
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Breasson L, Sardi C, Becattini B, Zani F, Solinas G. PI3Kγ ablation does not promote diabetes in db/db mice, but improves insulin sensitivity and reduces pancreatic β-cell apoptosis. FASEB J 2017; 32:319-329. [PMID: 28904022 DOI: 10.1096/fj.201700372rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 08/28/2017] [Indexed: 11/11/2022]
Abstract
PI3Kγ has emerged as a promising target for the treatment of obesity and insulin resistance; however, previous studies have indicated that PI3Kγ activity in pancreatic β cells is required for normal insulin secretion in response to glucose. Hence, a possible deterioration of insulin secretion capacity in patients who are predisposed to the failure of pancreatic β-cell function is a major concern for the pharmacologic inhibition of PI3Kγ. To address this issue, we investigated the effects of PI3Kγ ablation in db/db diabetic mice, a genetic model of obesity-driven β-cell failure and diabetes. Mice that lacked PI3Kγ were backcrossed into db/+ mice C57BL/KS (>10 generations) to obtain db/db-PI3Kγ-/- mice. db/db-PI3Kγ-/- mice and control db/db mice were phenotyped for glucose homeostasis, insulin sensitivity, insulin secretion, steatosis, metabolic inflammation, pancreatic islet morphometry, islet cellular composition, and inflammation. Pancreatic β-cell apoptosis and proliferation were also evaluated. db/db-PI3Kγ -/- mice and control db/db mice developed similar body weight, steatosis, glycemia, and insulin levels after a glucose load; however, db/db-PI3Kγ-/- mice displayed improved insulin tolerance, higher levels of fasting serum insulin, and lower pancreatic insulin content. In db/db-PI3Kγ-/- mice, the number of adipose tissue macrophages was similar to control, but displayed reduced adipose tissue neutrophils and M2-polarized adipose tissue gene expression. Finally, db/db-PI3Kγ-/- mice have more pancreatic β cells and larger islets than db/db mice, despite displaying similar islet inflammation. This phenotype could be explained by reduced β-cell apoptosis in db/db-PI3Kγ-/- mice compared with control db/db mice. Our results are consistent with the concept that the beneficial action of PI3Kγ ablation in obesity-driven glucose intolerance is largely a result of its leptin-dependent effects on adiposity and, to a lesser extent, the promotion of adipose tissue neutrophil recruitment and M1 polarization of gene expression. Of importance, our data challenge the concept that PI3Kγ is required for insulin secretion in response to glucose in vivo, and indicate that PI3Kγ ablation protects db/db mice from β-cell apoptosis and improves fasting insulin levels. We conclude that PI3Kγ inhibition in obese patients who are predisposed to β-cell failure is not expected to produce adverse effects on insulin secretion.-Breasson, L., Sardi, C., Becattini, B., Zani, F., Solinas, G. PI3Kγ ablation does not promote diabetes in db/db mice, but improves insulin sensitivity and reduces pancreatic β-cell apoptosis.
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Affiliation(s)
- Ludovic Breasson
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Claudia Sardi
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Barbara Becattini
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden
| | - Fabio Zani
- Cancer Research UK Beatson Institute, Glasgow, United Kingdom
| | - Giovanni Solinas
- Department of Molecular and Clinical Medicine, The Wallenberg Laboratory, University of Gothenburg, Gothenburg, Sweden;
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Solinas G, Becattini B. JNK at the crossroad of obesity, insulin resistance, and cell stress response. Mol Metab 2016; 6:174-184. [PMID: 28180059 PMCID: PMC5279903 DOI: 10.1016/j.molmet.2016.12.001] [Citation(s) in RCA: 268] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 11/28/2016] [Accepted: 12/02/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The cJun-N-terminal-kinase (JNK) plays a central role in the cell stress response, with outcomes ranging from cell death to cell proliferation and survival, depending on the specific context. JNK is also one of the most investigated signal transducers in obesity and insulin resistance, and studies have identified new molecular mechanisms linking obesity and insulin resistance. Emerging evidence indicates that whereas JNK1 and JNK2 isoforms promote the development of obesity and insulin resistance, JNK3 activity protects from excessive adiposity. Furthermore, current evidence indicates that JNK activity within specific cell types may, in specific stages of disease progression, promote cell tolerance to the stress associated with obesity and type-2 diabetes. SCOPE OF REVIEW This review provides an overview of the current literature on the role of JNK in the progression from obesity to insulin resistance, NAFLD, type-2 diabetes, and diabetes complications. MAJOR CONCLUSION Whereas current evidence indicates that JNK1/2 inhibition may improve insulin sensitivity in obesity, the role of JNK in the progression from insulin resistance to diabetes, and its complications is largely unresolved. A better understanding of the role of JNK in the stress response to obesity and type-2 diabetes, and the development of isoform-specific inhibitors with specific tissue distribution will be necessary to exploit JNK as possible drug target for the treatment of type-2 diabetes.
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Affiliation(s)
- Giovanni Solinas
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden.
| | - Barbara Becattini
- The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden
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Balakumar M, Raji L, Prabhu D, Sathishkumar C, Prabu P, Mohan V, Balasubramanyam M. High-fructose diet is as detrimental as high-fat diet in the induction of insulin resistance and diabetes mediated by hepatic/pancreatic endoplasmic reticulum (ER) stress. Mol Cell Biochem 2016; 423:93-104. [PMID: 27699590 DOI: 10.1007/s11010-016-2828-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 09/22/2016] [Indexed: 01/05/2023]
Abstract
In the context of high human consumption of fructose diets, there is an imperative need to understand how dietary fructose intake influence cellular and molecular mechanisms and thereby affect β-cell dysfunction and insulin resistance. While evidence exists for a relationship between high-fat-induced insulin resistance and metabolic disorders, there is lack of studies in relation to high-fructose diet. Therefore, we attempted to study the effect of different diets viz., high-fat diet (HFD), high-fructose diet (HFS), and a combination (HFS + HFD) diet on glucose homeostasis and insulin sensitivity in male Wistar rats compared to control animals fed with normal pellet diet. Investigations include oral glucose tolerance test, insulin tolerance test, histopathology by H&E and Masson's trichrome staining, mRNA expression by real-time PCR, protein expression by Western blot, and caspase-3 activity by colorimetry. Rats subjected to high-fat/fructose diets became glucose intolerant, insulin-resistant, and dyslipidemic. Compared to control animals, rats subjected to different combination of fat/fructose diets showed increased mRNA and protein expression of a battery of ER stress markers both in pancreas and liver. Transcription factors of β-cell function (INSIG1, SREBP1c and PDX1) as well as hepatic gluconeogenesis (FOXO1 and PEPCK) were adversely affected in diet-induced insulin-resistant rats. The convergence of chronic ER stress towards apoptosis in pancreas/liver was also indicated by increased levels of CHOP mRNA & increased activity of both JNK and Caspase-3 in rats subjected to high-fat/fructose diets. Our study exposes the experimental support in that high-fructose diet is equally detrimental in causing metabolic disorders.
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Affiliation(s)
- M Balakumar
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - L Raji
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - D Prabhu
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - C Sathishkumar
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - P Prabu
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - V Mohan
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India
| | - M Balasubramanyam
- Department of Cell and Molecular Biology and Dr. Rema Mohan High-Throughput Screening (HTS) Lab, Madras Diabetes Research Foundation & Dr. Mohan's Diabetes Specialties Centre, WHO Collaborating Centre for Non-Communicable Diseases Prevention & Control, Gopalapuram, Chennai, 600086, India.
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TAK1 inhibition prevents the development of autoimmune diabetes in NOD mice. Sci Rep 2015; 5:14593. [PMID: 26459028 PMCID: PMC4602205 DOI: 10.1038/srep14593] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 09/02/2015] [Indexed: 01/29/2023] Open
Abstract
Transforming growth factor-β activated kinase-1 (TAK1, Map3k7), a member of the mitogen-activated protein kinase kinase kinase (MAP3K) family, is essential in innate and adaptive immune responses. We postulated that blockade of TAK1 would affect autoimmune diabetes in non-obese diabetic (NOD) mice. Administration of 5Z-7-oxozeaenol (OZ), a TAK1 inhibitor, decreased the incidence and delayed the onset of autoimmune diabetes in both spontaneous and accelerated (cyclophosphamide-induced) experimental NOD mice. OZ also reduced insulitis, preserved islet function, increased the expression of α1- antitrypsin (AAT), and severely inhibited NF-κB and JNK/AP-1 signaling pathways in immune organs and pancreatic tissues. Importantly, TAK1 inhibition by OZ elicited a Th1 to Th2 cytokine shift, and increased TGF-β1 production in cultured T lymphocytes supernatants. Systemic TAK1 inhibition induced immature DCs with lower expressions of MHC-II and CD86, attenuated DC-mediated T cell proliferation in allogeneic MLR, and production of cytokine IL-12p70 in DCs suspensions. The results indicate that TAK1 inhibition with OZ was associated with a lower frequency of autoimmune diabetes in NOD mice. The net effect of TAK1 inhibition in NOD mice therefore appears to be protective rather than disease-enhancing. Strategies targeting TAK1 specifically in NOD mice might prove useful for the treatment of autoimmune diabetes in general.
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Abstract
Obesity is a new global pandemic, with growing incidence and prevalence. This disease is associated with increased risk of several pathologies, including diabetes, cardiovascular diseases, and cancer. The mechanisms underlying obesity-associated metabolic changes are the focus of efforts to identify new therapies. Stress-activated protein kinases (SAPK), including cJun N-terminal kinases (JNKs) and p38, are required for cellular responses to metabolic stress and therefore might contribute to the pathogenesis of obesity. Tissue-specific knockout models support a cell-type-specific role for JNK isoforms, in particular JNK1, highlighting its importance in cell homeostasis and organ crosstalk. However, more efforts are needed to elucidate the specific roles of other JNK isoforms and p38 family members in metabolism and obesity. This review provides an overview of the role of SAPKs in the regulation of metabolism.
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Affiliation(s)
- Elisa Manieri
- Myocardial Pathophysiology AreaFundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, CNIC, C/Melchor Fernandez Almagro, 2, 28029 Madrid, SpainDepartment of Immunology and OncologyCentro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, Madrid, Spain Myocardial Pathophysiology AreaFundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, CNIC, C/Melchor Fernandez Almagro, 2, 28029 Madrid, SpainDepartment of Immunology and OncologyCentro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, Madrid, Spain
| | - Guadalupe Sabio
- Myocardial Pathophysiology AreaFundación Centro Nacional de Investigaciones Cardiovasculares Carlos III, CNIC, C/Melchor Fernandez Almagro, 2, 28029 Madrid, SpainDepartment of Immunology and OncologyCentro Nacional de Biotecnología/CSIC, Campus de Cantoblanco, Madrid, Spain
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Hameed I, Masoodi SR, Mir SA, Nabi M, Ghazanfar K, Ganai BA. Type 2 diabetes mellitus: From a metabolic disorder to an inflammatory condition. World J Diabetes 2015; 6:598-612. [PMID: 25987957 PMCID: PMC4434080 DOI: 10.4239/wjd.v6.i4.598] [Citation(s) in RCA: 255] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/14/2014] [Accepted: 12/31/2014] [Indexed: 02/05/2023] Open
Abstract
Diabetes mellitus is increasing at an alarming rate and has become a global challenge. Insulin resistance in target tissues and a relative deficiency of insulin secretion from pancreatic β-cells are the major features of type 2 diabetes (T2D). Chronic low-grade inflammation in T2D has given an impetus to the field of immuno-metabolism linking inflammation to insulin resistance and β-cell dysfunction. Many factors advocate a causal link between metabolic stress and inflammation. Numerous cellular factors trigger inflammatory signalling cascades, and as a result T2D is at the moment considered an inflammatory disorder triggered by disordered metabolism. Cellular mechanisms like activation of Toll-like receptors, Endoplasmic Reticulum stress, and inflammasome activation are related to the nutrient excess linking pathogenesis and progression of T2D with inflammation. This paper aims to systematically review the metabolic profile and role of various inflammatory pathways in T2D by capturing relevant evidence from various sources. The perspectives include suggestions for the development of therapies involving the shift from metabolic stress to homeostasis that would favour insulin sensitivity and survival of pancreatic β-cells in T2D.
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Japtok L, Schmitz EI, Fayyaz S, Krämer S, Hsu LJ, Kleuser B. Sphingosine 1-phosphate counteracts insulin signaling in pancreatic β-cells via the sphingosine 1-phosphate receptor subtype 2. FASEB J 2015; 29:3357-69. [PMID: 25911610 DOI: 10.1096/fj.14-263194] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 04/16/2015] [Indexed: 01/04/2023]
Abstract
Glucolipotoxic stress has been identified as a key player in the progression of pancreatic β-cell dysfunction contributing to insulin resistance and the development of type 2 diabetes mellitus (T2D). It has been suggested that bioactive lipid intermediates, formed under lipotoxic conditions, are involved in these processes. Here, we show that sphingosine 1-phosphate (S1P) levels are not only increased in palmitate-stimulated pancreatic β-cells but also regulate β-cell homeostasis in a divergent manner. Although S1P possesses a prosurvival effect in β-cells, an enhanced level of the sphingolipid antagonizes insulin-mediated cell growth and survival via the sphingosine 1-phosphate receptor subtype 2 (S1P2) followed by an inhibition of Akt-signaling. In an attempt to investigate the role of the S1P/S1P2 axis in vivo, the New Zealand obese (NZO) diabetic mouse model, characterized by β-cell loss under high-fat diet (HFD) conditions, was used. The occurrence of T2D was accompanied by an increase of plasma S1P levels. To examine whether S1P contributes to the morphologic changes of islets via S1P2, the receptor antagonist JTE-013 was administered. Most interestingly, JTE-013 rescued β-cell damage clearly indicating an important role of the S1P2 in β-cell homeostasis. Therefore, the present study provides a new therapeutic strategy to diminish β-cell dysfunction and the development of T2D.
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Affiliation(s)
- Lukasz Japtok
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
| | - Elisabeth I Schmitz
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
| | - Susann Fayyaz
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
| | - Stephanie Krämer
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
| | - Leigh J Hsu
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
| | - Burkhard Kleuser
- *Faculty of Mathematics and Natural Science, Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Potsdam, Germany; German Institute of Human Nutrition, Max Rubner Laboratory, Nuthetal, Germany; and Lpath Incorporated, San Diego, California, USA
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Singh VP, Gurunathan C, Singh S, Singh B, Lakshmi BJ, Mishra AP, Kumar S. Genetic deletion of Wdr13 improves the metabolic phenotype of Lepr (db/db) mice by modulating AP1 and PPARγ target genes. Diabetologia 2015; 58:384-92. [PMID: 25417213 DOI: 10.1007/s00125-014-3438-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 10/15/2014] [Indexed: 01/09/2023]
Abstract
AIM/HYPOTHESIS Type 2 diabetes is a complex disease characterised by hyperglycaemia, hyperinsulinaemia, dyslipidaemia and insulin resistance accompanied by inflammation. Previously, we showed that mice lacking the Wdr13 gene had increased islet mass due to enhanced beta cell proliferation. We hypothesised that introgression of a Wdr13-null mutation, a beta cell-proliferative phenotype, into Lepr(db/db) mice, a beta cell-destructive phenotype, might rescue the diabetic phenotype of the latter. METHODS Wdr13-deficient mice were crossed with Lepr(db/db) mice to generate mice with the double mutation. We measured various serum metabolic variables of Wdr13(+/0)Lepr(db/db) and Wdr13(-/0) Lepr(db/db) mice. Further, we analysed the histopathology and gene expression of peroxisome proliferator-activated receptor (PPAR)γ and, activator protein (AP)1 targets in various metabolic tissues. RESULTS Lepr(db/db) mice with the Wdr13 deletion had a massively increased islet mass, hyperinsulinaemia and adipocyte hypertrophy. The increase in beta cell mass in Wdr13(-/0)Lepr(db/db) mice was due to an increase in beta cell proliferation. Hypertrophy of adipocytes may be the result of increase in transcription of Pparg and its target genes, leading in turn to increased expression of several lipogenic genes. We also observed a significant decrease in the expression of AP1 and nuclear factor κ light chain enhancer of activated B cells (NFκB) target genes involved in inflammation. CONCLUSIONS/INTERPRETATION This study provides evidence that loss of WD repeat domain 13 (WDR13) protein in the Lepr (db/db) mouse model of diabetes is beneficial. Based on these findings, we suggest that WDR13 may be a potential drug target for ameliorating hyperglycaemia and inflammation in diabetic conditions.
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Affiliation(s)
- Vijay P Singh
- National Facility for Transgenic and Gene Knockout Mice, Council of Scientific and Industrial Research-Centre for Cellular and Molecular Biology, Habsiguda, Hyderabad, India
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Chen L, Chen R, Wang H, Liang F. Mechanisms Linking Inflammation to Insulin Resistance. Int J Endocrinol 2015; 2015:508409. [PMID: 26136779 PMCID: PMC4468292 DOI: 10.1155/2015/508409] [Citation(s) in RCA: 312] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/04/2015] [Indexed: 12/14/2022] Open
Abstract
Obesity is now widespread around the world. Obesity-associated chronic low-grade inflammation is responsible for the decrease of insulin sensitivity, which makes obesity a major risk factor for insulin resistance and related diseases such as type 2 diabetes mellitus and metabolic syndromes. The state of low-grade inflammation is caused by overnutrition which leads to lipid accumulation in adipocytes. Obesity might increase the expression of some inflammatory cytokines and activate several signaling pathways, both of which are involved in the pathogenesis of insulin resistance by interfering with insulin signaling and action. It has been suggested that specific factors and signaling pathways are often correlated with each other; therefore, both of the fluctuation of cytokines and the status of relevant signaling pathways should be considered during studies analyzing inflammation-related insulin resistance. In this paper, we discuss how these factors and signaling pathways contribute to insulin resistance and the therapeutic promise targeting inflammation in insulin resistance based on the latest experimental studies.
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Affiliation(s)
- Li Chen
- Hubei University of Chinese Medicine, Wuhan 430061, China
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan 430061, China
| | - Rui Chen
- Integrated TCM and Western Medicine Department, Union Hospital, Tongji Medical College of Huazhong Science and Technology University, Wuhan 430022, China
| | - Hua Wang
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan 430061, China
- Acupuncture and Moxibustion College, Hubei University of Chinese Medicine, Wuhan 430061, China
| | - Fengxia Liang
- Hubei Provincial Collaborative Innovation Center of Preventive Treatment by Acupuncture and Moxibustion, Wuhan 430061, China
- Acupuncture and Moxibustion College, Hubei University of Chinese Medicine, Wuhan 430061, China
- *Fengxia Liang:
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40
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Hernandez ED, Lee SJ, Kim JY, Duran A, Linares JF, Yajima T, Müller TD, Tschöp MH, Smith SR, Diaz-Meco MT, Moscat J. A macrophage NBR1-MEKK3 complex triggers JNK-mediated adipose tissue inflammation in obesity. Cell Metab 2014; 20:499-511. [PMID: 25043814 PMCID: PMC4156534 DOI: 10.1016/j.cmet.2014.06.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/18/2014] [Accepted: 05/19/2014] [Indexed: 12/21/2022]
Abstract
The c-Jun NH(2)-terminal kinase (JNK) is a critical determinant of obesity-associated inflammation and glucose intolerance. The upstream mechanisms controlling this pathway are still unknown. Here we report that the levels of the PB1 domain-containing adaptor NBR1 correlated with the expression of proinflammatory molecules in adipose tissue from human patients with metabolic syndrome, suggesting that NBR1 plays a key role in adipose-tissue inflammation. We also show that NBR1 inactivation in the myeloid compartment impairs the function, M1 polarization, and chemotactic activity of macrophages; prevents inflammation of adipose tissue; and improves glucose tolerance in obese mice. Furthermore, we demonstrate that an interaction between the PB1 domains of NBR1 and the mitogen-activated kinase kinase 3 (MEKK3) enables the formation of a signaling complex required for the activation of JNK. Together, these discoveries identify an NBR1-MEKK3 complex as a key regulator of JNK signaling and adipose tissue inflammation in obesity.
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Affiliation(s)
- Eloy D Hernandez
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Sang Jun Lee
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Ji Young Kim
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Angeles Duran
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Juan F Linares
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Tomoko Yajima
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München & Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 85764 Munich, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München & Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 85764 Munich, Germany
| | - Steven R Smith
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Sanford-Burnham Medical Research Institute, FL 32789, USA
| | | | - Jorge Moscat
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
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Balakrishnan S, Sadasivam M, Kannan A, Panneerselvam A, Prahalathan C. Glucose modulates Pax6 expression through the JNK/p38 MAP kinase pathway in pancreatic beta-cells. Life Sci 2014; 109:1-7. [PMID: 24953606 DOI: 10.1016/j.lfs.2014.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 06/04/2014] [Accepted: 06/07/2014] [Indexed: 02/08/2023]
Abstract
AIM The paired and homeodomain-containing transcription factor, paired box 6 (Pax6), has shown to play pivotal roles in beta-cell function, including cell survival, insulin biosynthesis and secretion. The present study investigates the signaling events that regulate the modulation of Pax6 expression by glucose and the role of this modulation in cell survival in rat insulinoma-1E (INS-1E) cells. MAIN METHODS INS-1E cells were incubated on 1mM (low) or 25 mM (high) glucose overnight. To elucidate the signaling pathways that regulate Pax6 expression, we utilized specific inhibitors. The siRNA transfection of Pax6 into INS-1E cells was performed by electroporation. The mRNA and protein levels were determined by real-time PCR and Western blotting, respectively. KEY FINDINGS We found that the mRNA and protein levels of Pax6 were reduced by approximately 4-fold in high, compared to low, glucose-treated cells. Staurosporine, the c-Jun N-terminal kinase (JNK) inhibitor SP600125 and the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580 significantly increased Pax6 levels in high glucose-treated INS-1E cells compared to their respective controls. However, neither calcium ionophore nor the extracellular signal-regulated kinase (ERK) inhibitor U0126 resulted in any alteration in Pax6 protein expression. Further, a siRNA-mediated knockdown of Pax6 significantly decreased the expression of tumor-suppressor phosphatase with tensin homology (PTEN) while increasing cell viability in low glucose-treated INS-1E cells. SIGNIFICANCE This study addresses the signaling events that regulate the glucose-dependent expression of Pax6 and the role of these events in cell survival in pancreatic beta cells.
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Affiliation(s)
| | - Mohanraj Sadasivam
- Department of Biochemistry, Bharathidasan University, Tiruchirappalli 620 024, India
| | - Arun Kannan
- Department of Biochemistry, Bharathidasan University, Tiruchirappalli 620 024, India
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Merry TL, Tran M, Stathopoulos M, Wiede F, Fam BC, Dodd GT, Clarke I, Watt MJ, Andrikopoulos S, Tiganis T. High-fat-fed obese glutathione peroxidase 1-deficient mice exhibit defective insulin secretion but protection from hepatic steatosis and liver damage. Antioxid Redox Signal 2014; 20:2114-29. [PMID: 24252128 DOI: 10.1089/ars.2013.5428] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AIMS Reactive oxygen species (ROS) such as H2O2 can promote signaling through the inactivation of protein tyrosine phosphatases (PTPs). However, in obesity, the generation of ROS exceeds the antioxidant reserve and can contribute to the promotion of insulin resistance. Glutathione peroxidase 1 (Gpx1) is an antioxidant enzyme that eliminates H2O2. Here, we have used Gpx1(-/-) mice to assess the impact of oxidative stress on glucose homeostasis in the context of obesity. RESULTS Gpx1(-/-) mice fed an obesogenic high-fat diet for 12 weeks exhibited systemic oxidative stress and hyperglycemia, but had unaltered whole-body insulin sensitivity, improved hepatic insulin signaling, and decreased whole-body glucose production. High-fat-fed Gpx1(-/-) mice also exhibited decreased hepatic steatosis and liver damage accompanied by decreased plasma insulin and decreased glucose-induced insulin secretion. The decreased insulin secretion was associated with reduced islet β cell pancreatic and duodenal homeobox-1 (Pdx1) and insulin content, elevated pancreatic PTP oxidation (including PTPN2 oxidation), and elevated signal transducer and activator of transcription 1 (STAT1) Y701 phosphorylation. INNOVATION AND CONCLUSION Taken together, these results are consistent with H2O2 inactivating pancreatic PTPs (such as the STAT1 phosphatase PTPN2) for the promotion of STAT-1 signaling to suppress Pdx1 expression and differentiation and, consequently, reduce β cell insulin secretion. We propose that the decreased insulin secretion, in turn, results in decreased hepatic lipogenesis and steatosis, attenuates liver damage, and improves hepatic insulin signaling to suppress hepatic glucose production. Limiting insulin secretion may help combat the development of hepatic steatosis and liver damage in diet-induced obesity.
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Affiliation(s)
- Troy L Merry
- 1 Department of Biochemistry and Molecular Biology, Monash University , Victoria, Australia
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Montane J, Cadavez L, Novials A. Stress and the inflammatory process: a major cause of pancreatic cell death in type 2 diabetes. Diabetes Metab Syndr Obes 2014; 7:25-34. [PMID: 24520198 PMCID: PMC3917922 DOI: 10.2147/dmso.s37649] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Type 2 diabetes (T2D) is a complex metabolic disorder characterized by hyperglycemia in the context of insulin resistance, which precedes insulin deficiency as a result of β-cell failure. Accumulating evidence indicates that β-cell loss in T2D results as a response to the combination of oxidative stress and endoplasmic reticulum (ER) stress. Failure of the ER's adaptive capacity and further activation of the unfolded protein response may trigger macroautophagy (hereafter referred as autophagy) as a process of self-protection and inflammation. Many studies have shown that inflammation plays a very important role in the pathogenesis of T2D. Inflammatory mechanisms and cytokine production activated by stress via the inflammasome may further alter the normal structure of β-cells by inducing pancreatic islet cell apoptosis. Thus, the combination of oxidative and ER stress, together with autophagy insufficiency and inflammation, may contribute to β-cell death or dysfunction in T2D. Therapeutic approaches aimed at ameliorating stress and inflammation may therefore prove to be promising targets for the development of new diabetes treatment methods. Here, we discuss different mechanisms involved in stress and inflammation, and the role of antioxidants, endogenous and chemical chaperones, and autophagic pathways, which may shift the tendency from ER stress and apoptosis toward cell survival. Strategies targeting cell survival can be essential for relieving ER stress and reestablishing homeostasis, which may diminish inflammation and prevent pancreatic β-cell death associated with T2D.
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Affiliation(s)
- Joel Montane
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Lisa Cadavez
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Anna Novials
- Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
- Correspondence: Anna Novials, Diabetes and Obesity Research Laboratory, Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic de Barcelona, c/Rosello, 149-153 08036, Barcelona, Spain, Tel +34 93 227 5400, Fax +34 93 312 9403, Email
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