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Moon JH, Choe HJ, Lim S. Pancreatic beta-cell mass and function and therapeutic implications of using antidiabetic medications in type 2 diabetes. J Diabetes Investig 2024; 15:669-683. [PMID: 38676410 PMCID: PMC11143426 DOI: 10.1111/jdi.14221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/23/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Nowadays, the focus of diabetes treatment has switched from lowering the glucose level to preserving glycemic homeostasis and slowing the disease progression. The main pathophysiology of both type 1 diabetes and long-standing type 2 diabetes is pancreatic β-cell mass loss and dysfunction. According to recent research, human pancreatic β-cells possess the ability to proliferate in response to elevated insulin demands. It has been demonstrated that in insulin-resistant conditions in humans, such as obesity or pregnancy, the β-cell mass increases. This ability could be helpful in developing novel treatment approaches to restore a functional β-cell mass. Treatment strategies aimed at boosting β-cell function and mass may be a useful tool for managing diabetes mellitus and stopping its progression. This review outlines the processes of β-cell failure and detail the many β-cell abnormalities that manifest in people with diabetes mellitus. We also go over standard techniques for determining the mass and function of β-cells. Lastly, we provide the therapeutic implications of utilizing antidiabetic drugs in controlling the mass and function of pancreatic β-cells.
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Affiliation(s)
- Joon Ho Moon
- Department of Internal MedicineSeoul National University College of MedicineSeongnamSouth Korea
- Department of Internal MedicineSeoul National University Bundang HospitalSeongnamSouth Korea
| | - Hun Jee Choe
- Department of Internal MedicineHallym University Dongtan Sacred Heart HospitalHwaseongSouth Korea
| | - Soo Lim
- Department of Internal MedicineSeoul National University College of MedicineSeongnamSouth Korea
- Department of Internal MedicineSeoul National University Bundang HospitalSeongnamSouth Korea
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2
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Siwan D, Nandave M, Gilhotra R, Almalki WH, Gupta G, Gautam RK. Unlocking β-cell restoration: The crucial role of PDX1 in diabetes therapy. Pathol Res Pract 2024; 254:155131. [PMID: 38309018 DOI: 10.1016/j.prp.2024.155131] [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: 12/01/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/05/2024]
Abstract
Diabetes has been a significant healthcare problem worldwide for a considerable period. The primary objective of diabetic treatment plans is to control the symptoms associated with the pathology. To effectively combat diabetes, it is crucial to comprehend the disease's etiology, essential factors, and the relevant processes involving β-cells. The development of the pancreas, maturation, and maintenance of β-cells, and their role in regular insulin function are all regulated by PDX1. Therefore, understanding the regulation of PDX1 and its interactions with signaling pathways involved in β-cell differentiation and proliferation are crucial elements of alternative diabetes treatment strategies. The present review aims to explore the protective role of PDX1 in β-cell proliferation through signaling pathways. The main keywords chosen for this review include "PDX1 for β-cell mass," "β-cell proliferation," "β-cell restoration via PDX1," and "mechanism of PDX1 in β-cells." A comprehensive literature search was conducted using various internet search engines, such as PubMed, Science Direct, and other publication databases. We summarize several approaches to generating β-cells from alternative cell sources, employing PDX1 under various modified growth conditions and different transcriptional factors. Our analysis highlights the unique potential of PDX1 as a promising target in molecular and cell-based therapies for diabetes.
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Affiliation(s)
- Deepali Siwan
- Department of Pharmacology, Delhi Pharmaceutical Sciences and Research University (DPSRU), New Delhi 110017, India
| | - Mukesh Nandave
- Department of Pharmacology, Delhi Pharmaceutical Sciences and Research University (DPSRU), New Delhi 110017, India.
| | - Ritu Gilhotra
- School of Pharmacy, Suresh Gyan Vihar University, Mahal Road, Jagatpura, Jaipur, India
| | - Waleed Hassan Almalki
- Department of Pharmacology, College of Pharmacy, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Gaurav Gupta
- Center for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, India; School of Pharmacy, Graphic Era Hill University, Dehradun 248007, India; Centre of Medical and Bio-allied Health Sciences Research, Ajman University, Ajman, Ajman, 346, United Arab Emirates
| | - Rupesh K Gautam
- Department of Pharmacology, Indore Institute of Pharmacy, IIST Campus, Opposite IIM Indore, Rau-Pithampur Road, Indore 453331, Madhya Pradesh, India
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Riaz F, Wei P, Pan F. PPARs at the crossroads of T cell differentiation and type 1 diabetes. Front Immunol 2023; 14:1292238. [PMID: 37928539 PMCID: PMC10623333 DOI: 10.3389/fimmu.2023.1292238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/11/2023] [Indexed: 11/07/2023] Open
Abstract
T-cell-mediated autoimmune type 1 diabetes (T1D) is characterized by the immune-mediated destruction of pancreatic beta cells (β-cells). The increasing prevalence of T1D poses significant challenges to the healthcare system, particularly in countries with struggling economies. This review paper highlights the multifaceted roles of Peroxisome Proliferator-Activated Receptors (PPARs) in the context of T1D, shedding light on their potential as regulators of immune responses and β-cell biology. Recent research has elucidated the intricate interplay between CD4+ T cell subsets, such as Tregs and Th17, in developing autoimmune diseases like T1D. Th17 cells drive inflammation, while Tregs exert immunosuppressive functions, highlighting the delicate balance crucial for immune homeostasis. Immunotherapy has shown promise in reinstating self-tolerance and restricting the destruction of autoimmune responses, but further investigations are required to refine these therapeutic strategies. Intriguingly, PPARs, initially recognized for their role in lipid metabolism, have emerged as potent modulators of inflammation in autoimmune diseases, particularly in T1D. Although evidence suggests that PPARs affect the β-cell function, their influence on T-cell responses and their potential impact on T1D remains largely unexplored. It was noted that PPARα is involved in restricting the transcription of IL17A and enhancing the expression of Foxp3 by minimizing its proteasomal degradation. Thus, antagonizing PPARs may exert beneficial effects in regulating the differentiation of CD4+ T cells and preventing T1D. Therefore, this review advocates for comprehensive investigations to delineate the precise roles of PPARs in T1D pathogenesis, offering innovative therapeutic avenues that target both the immune system and pancreatic function. This review paper seeks to bridge the knowledge gap between PPARs, immune responses, and T1D, providing insights that may revolutionize the treatment landscape for this autoimmune disorder. Moreover, further studies involving PPAR agonists in non-obese diabetic (NOD) mice hold promise for developing novel T1D therapies.
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Affiliation(s)
- Farooq Riaz
- Shenzhen Institute of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, China
| | - Ping Wei
- Department of Otolaryngology, Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders (Chongqing), China International Science and Technology Cooperation base of Child Development and Critical Disorders, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Fan Pan
- Shenzhen Institute of Advanced Technology (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, China
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PDX-1: A Promising Therapeutic Target to Reverse Diabetes. Biomolecules 2022; 12:biom12121785. [PMID: 36551213 PMCID: PMC9775243 DOI: 10.3390/biom12121785] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/18/2022] [Accepted: 11/19/2022] [Indexed: 12/02/2022] Open
Abstract
The pancreatic duodenum homeobox-1 (PDX-1) is a transcription factor encoded by a Hox-like homeodomain gene that plays a crucial role in pancreatic development, β-cell differentiation, and the maintenance of mature β-cell functions. Research on the relationship between PDX-1 and diabetes has gained much attention because of the increasing prevalence of diabetes melitus (DM). Recent studies have shown that the overexpression of PDX-1 regulates pancreatic development and promotes β-cell differentiation and insulin secretion. It also plays a vital role in cell remodeling, gene editing, and drug development. Conversely, the absence of PDX-1 increases susceptibility to DM. Therefore, in this review, we summarized the role of PDX-1 in pancreatic development and the pathogenesis of DM. A better understanding of PDX-1 will deepen our knowledge of the pathophysiology of DM and provide a scientific basis for exploring PDX-1 as a potential target for treating diabetes.
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Molecular dissection of cellular response of pancreatic islet cells to Bisphenol-A (BPA): a comprehensive review. Biochem Pharmacol 2022; 201:115068. [DOI: 10.1016/j.bcp.2022.115068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/11/2022] [Accepted: 04/25/2022] [Indexed: 12/15/2022]
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Jetton TL, Flores-Bringas P, Leahy JL, Gupta D. SetD7 (Set7/9) is a novel target of PPARγ that promotes the adaptive pancreatic β-cell glycemic response. J Biol Chem 2021; 297:101250. [PMID: 34592314 PMCID: PMC8526774 DOI: 10.1016/j.jbc.2021.101250] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/20/2021] [Accepted: 09/24/2021] [Indexed: 11/25/2022] Open
Abstract
Loss of functional pancreatic β-cell mass leads to type 2 diabetes (T2D), attributable to modified β-cell-dependent adaptive gene expression patterns. SetD7 is a histone methyltransferase enriched in pancreatic islets that mono- and dimethylates histone-3-lysine-4 (H3K4), promoting euchromatin modifications, and also maintains the regulation of key β-cell function and survival genes. However, the transcriptional regulation of this important epigenetic modifier is unresolved. Here we identified the nuclear hormone receptor peroxisome proliferator-activated receptor-gamma (PPARγ) as a major transcriptional regulator of SetD7 and provide evidence for direct binding and functionality of PPARγ in the SetD7 promoter region. Furthermore, constitutive shRNA-mediated PPARγ knockdown in INS-1 β-cells or pancreas-specific PPARγ deletion in mice led to downregulation of SetD7 expression as well as its nuclear enrichment. The relevance of the SetD7-PPARγ interaction in β-cell adaptation was tested in normoglycemic 60% partial pancreatectomy (Px) and hyperglycemic 90% Px rat models. Whereas a synergistic increase in islet PPARγ and SetD7 expression was observed upon glycemic adaptation post-60% Px, in hyperglycemic 90% Px rats, islet PPARγ, and PPARγ targets SetD7 and Pdx1 were downregulated. PPARγ agonist pioglitazone treatment in 90% Px rats partially restored glucose homeostasis and β-cell mass and enhanced expression of SetD7 and Pdx1. Collectively, these data provide evidence that the SetD7-PPARγ interaction serves as an important element of the adaptive β-cell response.
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Affiliation(s)
- Thomas L Jetton
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Patricio Flores-Bringas
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - John L Leahy
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Dhananjay Gupta
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Larner College of Medicine, University of Vermont, Burlington, Vermont, USA.
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7
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Jo J, Lee D, Park YH, Choi H, Han J, Park DH, Choi YK, Kwak J, Yang MK, Yoo JW, Moon HR, Geum D, Kang KS, Yun H. Discovery and optimization of novel 3-benzyl-N-phenyl-1H-pyrazole-5-carboxamides as bifunctional antidiabetic agents stimulating both insulin secretion and glucose uptake. Eur J Med Chem 2021; 217:113325. [PMID: 33765605 DOI: 10.1016/j.ejmech.2021.113325] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/08/2021] [Accepted: 02/19/2021] [Indexed: 12/01/2022]
Abstract
A novel series of 3-benzyl-N-phenyl-1H-pyrazole-5-carboxamides was designed, synthesized and evaluated for their biological activities on glucose-stimulated insulin secretion (GSIS). The cytotoxicity of all 41 novel compounds was screened to assess their pharmacological safety in pancreatic β-cells. A two-step optimization process was carried out to establish the structure-activity relationship for this class and subsequently we identified the most active analogue 26. Further modification study of 26 evidenced the necessity of N-hydrogens in the core architecture. Protein expression analysis suggested that 26 increases insulin secretion via the activation of the upstream effector of pancreatic and duodenal homeobox 1 (PDX-1), which is an important factor promoting GSIS. Moreover, the administration of 26 effectively augmented glucose uptake in C2C12 myotube cells via the suppression of Mitsugumin 53 (MG53), an insulin receptor substrate 1 (IRS-1) ubiquitination E3 ligase.
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Affiliation(s)
- Jeyun Jo
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Dahae Lee
- College of Korean Medicine, Gachon University, Seongnam, 13120, Republic of Korea
| | - Yeong Hye Park
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyeonjin Choi
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Jinhee Han
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Do Hwi Park
- College of Korean Medicine, Gachon University, Seongnam, 13120, Republic of Korea
| | - You-Kyung Choi
- College of Korean Medicine, Gachon University, Seongnam, 13120, Republic of Korea
| | - Jinsook Kwak
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Min-Kyu Yang
- Mother's Pharmaceutical, Seoul, 08506, Republic of Korea
| | - Jin-Wook Yoo
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyung Ryong Moon
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea
| | - Dongho Geum
- Department of Biomedical Sciences, Korea University Medical School, Seoul, 02841, Republic of Korea
| | - Ki Sung Kang
- College of Korean Medicine, Gachon University, Seongnam, 13120, Republic of Korea.
| | - Hwayoung Yun
- College of Pharmacy, Pusan National University, Busan, 46241, Republic of Korea.
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The Chemical Constituents from Fruits of Catalpa bignonioides Walt. and Their α-Glucosidase Inhibitory Activity and Insulin Secretion Effect. Molecules 2021; 26:molecules26020362. [PMID: 33445612 PMCID: PMC7826643 DOI: 10.3390/molecules26020362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 11/24/2022] Open
Abstract
Catalpa pod has been used in traditional medicine for the treatment of diabetes mellitus in South America. Studies on the constituents of Catalpa species have shown that it is rich in iridoids. In the present study, three previously undescribed compounds (2–4), including two secoiridoid derivatives along with twelve known compounds, were isolated from the fruits of Catalpa bignonioides Walt. In addition, fully assigned 13C-NMR of 5,6-dihydroxy-7,4’-dimethoxyflavone-6-O-sophoroside (1) is reported for the first time in the present study. The structures of compounds were determined on the basis of extensive spectroscopic methods, including UV, IR, 1D, and 2D NMR, mass spectroscopy, and CD spectroscopic data. All the isolated compounds were evaluated for α-glucosidase inhibitory activity. Among the tested compounds, compounds 2, 3, and 9 exhibited significant inhibitory activity against α-glucosidase enzyme assay. Meanwhile, the effect of compounds 2, 3, and 9 on glucose-stimulated insulin secretion (GSIS) was measured using pancreatic β-cells. Compounds 2, 3, and 9 exhibited non-cytotoxicity-stimulated insulin secretion in INS-1 cells. The expression levels of proteins associated with β-cell function and insulin secretion such as phosphorylation of total insulin receptor substrate-2 (IRS-2), phosphatidylinositol 3-kinase (PI3K), Akt, activated pancreatic duodenal homeobox-1 (PDX-1), and peroxisome proliferator-activated receptor-γ (PPAR-γ) were increased in INS-1 cells after treatment with compounds 2, 3, and 9. The findings of the present study could provide a scientific warrant for their application as a potential antidiabetic agent.
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Rahmani S, Vakhshiteh F, Hodjat M, Sahranavardfard P, Hassani S, Ghafour Broujerdi E, Rahimifard M, Gholami M, Baeeri M, Abdollahi M. Gene-Environmental Interplay in Bisphenol A Subchronic Animal Exposure: New Insights into the Epigenetic Regulation of Pancreatic Islets. Chem Res Toxicol 2020; 33:2338-2350. [PMID: 32701268 DOI: 10.1021/acs.chemrestox.0c00109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Endocrine-disrupting chemicals (EDCs) such as bisphenol A (BPA), which is widely used in the plastic industry, have recently been considered to be involved in the pathogenesis of metabolic disorders, including obesity and diabetes. The present study aimed to examine the potentially detrimental effects of BPA on glucose and energy metabolism at the epigenetic level. The blood glucose profile of Wistar rats receiving different oral doses of BPA over 28 days was assessed. At the end of the treatment, the islets of Langerhans were isolated and purified, and their RNA content was extracted. MicroRNA (miRNA) profiling was evaluated using the next generation sequencing (NGS) method. After performing bioinformatic analysis of the NGS data, the gene ontology and data enrichment in terms of significantly disturbed miRNAs were evaluated through different databases, including Enrichr and DIANA tools. Additionally, the DNA methylation and the level of expression of two critical genes in glucose metabolism (PPARγ, Pdx1) were assessed. Subchronic BPA exposure (406 mg/kg/day) disturbed the blood glucose profile (fasting blood glucose and oral glucose tolerance) of Wistar rats and resulted in considerable cytotoxicity. NGS data analyses revealed that the expression of some crucial miRNAs involved in β-cell metabolism and diabetes occurrence and development, including miR-375, miR-676, miR-126-a, and miR-340-5p, was significantly disrupted. According to the DNA methylation evaluation, both PPARγ and Pdx1 genes underwent changes in the methylation level at particular loci on the gene's promoter. The expression levels of these genes were upregulated and downregulated, respectively. Overall, subchronic BPA exposure could cause epigenetic dysregulation at the gene level and interfere with the expression of key miRNAs and the methylation process of genes involved in glucose homeostasis. Understanding the exact underlying mechanisms by which BPA and other EDCs induce endocrine disturbance could be of great importance in the way of finding new preventive and therapeutic approaches.
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Affiliation(s)
- Soheila Rahmani
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Faezeh Vakhshiteh
- Nanotechnology Research Centre, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Mahshid Hodjat
- Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Parisa Sahranavardfard
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran 16635-148, Iran
| | - Shokoufeh Hassani
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Elmira Ghafour Broujerdi
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Mahban Rahimifard
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Mahdi Gholami
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Maryam Baeeri
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
| | - Mohammad Abdollahi
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS) and Department of Toxicology and Pharmacology, School of Pharmacy, Tehran University of Medical Sciences, Tehran 1417614411, Iran
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Xiong J, Sun P, Wang Y, Hua X, Song W, Wang Y, Wu J, Yu W, Liu G, Chen L. Heterozygous deletion of Seipin in islet beta cells of male mice has an impact on insulin synthesis and secretion through reduced PPARγ expression. Diabetologia 2020; 63:338-350. [PMID: 31776610 DOI: 10.1007/s00125-019-05038-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/03/2019] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) is an autosomal recessive disorder characterised by lipodystrophy and insulin resistance. BSCL2 is caused by loss-of-function mutations in the Seipin gene (also known as Bscl2). Deletion of this gene in mice induces insulin resistance, glucose intolerance and a loss of adipose tissue. This study evaluated the effects of genetic deletion of Seipin on islet beta cell function. METHODS We examined seipin expression in islet cells and measured glucose profiles, insulin synthesis, glucose-stimulated insulin secretion (GSIS), islet expression of peroxisome proliferator-activated receptor γ (PPARγ), levels of Pdx-1, Nkx6.1, Glut2 (also known as Slc2a2) and proinsulin mRNA, nuclear translocation of pancreatic duodenal homeobox 1 (PDX-1), islet numbers, and beta cell mass and proliferation in male and female Seipin-knockout homozygous (Seipin-/-) and heterozygous (Seipin+/-) mice. RESULTS Male and female Seipin-/- mice displayed glucose intolerance, insulin resistance, hyperinsulinaemia and a lack of adipose tissue. By contrast, male but not female Seipin+/- mice showed glucose intolerance without adipose tissue loss or insulin resistance. Seipin was highly expressed in islet beta cells in wild-type mice. Expression of islet PPARγ was reduced in male Seipin-/- and Seipin+/- mice but not in female Seipin-/- or Seipin+/- mice. Treatment of male Seipin+/- mice with rosiglitazone corrected the glucose intolerance. Male Seipin+/- mice displayed a decrease in islet insulin concentration and GSIS with low expression of Pdx-1, Nkx6.1, Glut2 and proinsulin, and a decline in PDX-1 nuclear translocation; these changes were rescued by rosiglitazone administration. Male Seipin-/- mice showed obvious, but rosiglitazone-sensitive, increases in islet insulin concentration, islet number and beta cell mass and proliferation, with a notable decline in GSIS. Ovariectomised female Seipin+/- mice displayed glucose intolerance and deficits in insulin synthesis and secretion, with a decline in islet PPARγ level; these deleterious effects were reversed by administration of oestradiol or rosiglitazone. CONCLUSIONS/INTERPRETATION Heterozygous deletion of Seipin in islet beta cells impacts on insulin synthesis and secretion through reduced PPARγ expression. This leads to glucose intolerance and is relieved by oestradiol, which rescues PPARγ expression.
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Affiliation(s)
- Jianwei Xiong
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Peng Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Ya Wang
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China
| | - Xu Hua
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China
| | - Wenyu Song
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Yan Wang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Jie Wu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Wenfeng Yu
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, 550004, China.
| | - George Liu
- Institute of Cardiovascular Sciences, Peking University and Key Laboratory of Cardiovascular Sciences, China Administration of Education, Beijing, 100191, China.
| | - Ling Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China.
- Department of Physiology, Nanjing Medical University, Longmian Road 101, Nanjing, 211166, China.
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11
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Rahimi M, Sajadimajd S, Mahdian Z, Hemmati M, Malekkhatabi P, Bahrami G, Mohammadi B, Miraghaee S, Hatami R, Mansouri K, Moahammadi Motlagh HR, Keshavarzi S, Derakhshankhah H. Characterization and anti-diabetic effects of the oligosaccharide fraction isolated from Rosa canina in STZ-Induced diabetic rats. Carbohydr Res 2020; 489:107927. [PMID: 32062396 DOI: 10.1016/j.carres.2020.107927] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 12/19/2022]
Abstract
Diabetes mellitus is the most common metabolic disorder characterized by chronic hyperglycemia. There has been a surge of research studies aiming to use natural products in the management of diabetes. The objective of this study was to isolate and characterize the structure and anti-diabetic mechanisms of the main ingredient from Rosa canina. The oligosaccharide was isolated from Rosa canina fruits and characterized by a combination of FTIR, NMR and Mass spectrometry. Wistar rats were divided into negative control, diabetic (type 2), isolated oligosaccharide (IO)-treated diabetic and positive diabetic controls. Oral glucose tolerance, gluconeogenesis and α-glucosidase inhibitory tests as well as immunohistochemistry and quantitative real time-PCR were performed to elucidate the molecular anti-diabetic mechanisms of IO. Structural analyses confirmed the oligosaccharide structure of isolated fraction. Gluconeogenesis and α-glucosidase activity were inhibited by IO in diabetic rats. The oral glucose tolerance test was improved significantly in the group treated with the IO (P < 0.05). Pancreatic β-cells and tissue pathological examination showed a significant improvement after the treatment period. In addition, the expression of Ngn3, Nkx6.1 and insulin increased in oligosaccharide-treated compared to untreated diabetic rats. Owing to the verified anti-diabetic effects and regenerative potential, isolated oligosaccharide could be considered as the promising drug in the management of diabetes.
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Affiliation(s)
- Mehrali Rahimi
- Department of Internal Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | | | - Zahra Mahdian
- School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Marayam Hemmati
- School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Peyman Malekkhatabi
- School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Gholamreza Bahrami
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran; School of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Bahareh Mohammadi
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Shahram Miraghaee
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Razieh Hatami
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Kamran Mansouri
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Hamid Reza Moahammadi Motlagh
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Samira Keshavarzi
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Hossein Derakhshankhah
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
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12
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Abstract
Peroxisome proliferator-activated receptors (PPARs) are a family of transcription factors with a key role in glucose and lipid metabolism. PPARs are expressed in many cell types including pancreatic beta cells and immune cells, where they regulate insulin secretion and T cell differentiation, respectively. Moreover, various PPAR agonists prevent diabetes in the non-obese diabetic (NOD) mouse model of type 1 diabetes. PPARs are thus of interest in type 1 diabetes (T1D) as they represent a novel approach targeting both the pancreas and the immune system. In this review, we examine the role of PPARs in immune responses and beta cell biology and their potential as targets for treatment of T1D.
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13
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Kwon MJ, Lee YJ, Jung HS, Shin HM, Kim TN, Lee SH, Rhee BD, Kim MK, Park JH. The direct effect of lobeglitazone, a new thiazolidinedione, on pancreatic beta cells: A comparison with other thiazolidinediones. Diabetes Res Clin Pract 2019; 151:209-223. [PMID: 30954516 DOI: 10.1016/j.diabres.2019.04.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/14/2019] [Accepted: 04/01/2019] [Indexed: 12/11/2022]
Abstract
AIMS The direct effects of thiazolidinediones (TZDs) on pancreatic beta cells have been controversial. The aim of this study was to find out whether a novel TZD, lobeglitazone, has beneficial effects on pancreatic beta cells and db/db mice compared to those of other TZDs. METHODS INS-1 cells were incubated at a high-glucose concentration with various concentrations of troglitazone, rosiglitazone, pioglitazone, and lobeglitazone. Apoptosis and proliferation of beta cells, markers for ER stress and glucose-stimulated insulin secretion (GSIS) were assessed. In addition, C57BL/6 db/db mice were treated with pioglitazone or lobeglitazone for 4 weeks, and metabolic parameters and the configuration of pancreatic islets were also examined. RESULTS Lobeglitazone and other TZDs decreased INS-1 cell apoptosis in high-glucose conditions. Lobeglitazone and other TZDs significantly decreased hyperglycemia-induced increases in ER stress markers and increased GSIS. Metabolic parameters showed greater improvement in db/db mice treated with pioglitazone and lobeglitazone than in control mice. Islet size, cell proliferation, and beta cell mass were increased, and collagen surrounding the islets was decreased in treated mice. CONCLUSIONS Lobeglitazone showed beneficial effects on beta cell survival and function against hyperglycemia. The prosurvival and profunction effects of lobeglitazone were comparable to those of other TZDs.
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Affiliation(s)
- Min Jeong Kwon
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea; Paik Institute for Clinical Research, Molecular Therapy Lab, Inje University, Busan, Republic of Korea
| | - Yong Jae Lee
- CKD Research Institute, Yongin, Gyeonggi-do, Republic of Korea
| | - Hye Sook Jung
- Paik Institute for Clinical Research, Molecular Therapy Lab, Inje University, Busan, Republic of Korea
| | - Hyun Mi Shin
- Paik Institute for Clinical Research, Molecular Therapy Lab, Inje University, Busan, Republic of Korea
| | - Tae Nyun Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea
| | - Soon Hee Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea
| | - Byoung Doo Rhee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea
| | - Mi-Kyung Kim
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea; Paik Institute for Clinical Research, Molecular Therapy Lab, Inje University, Busan, Republic of Korea.
| | - Jeong Hyun Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Inje University, Busan, Republic of Korea; Paik Institute for Clinical Research, Molecular Therapy Lab, Inje University, Busan, Republic of Korea.
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14
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Zhu K, Qian L, Lin Y, An L, Mu G, Ma G, Ren L. Pioglitazone Ameliorates Atorvastatin-Induced Islet Cell Dysfunction through Activation of FFA1 in INS-1 Cells. J Diabetes Res 2019; 2019:5245063. [PMID: 30863781 PMCID: PMC6378042 DOI: 10.1155/2019/5245063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/14/2018] [Accepted: 12/31/2018] [Indexed: 11/17/2022] Open
Abstract
Increasing evidence shows that statins increase the risk of new-onset diabetes mellitus, but the exact mechanism is not clearly known. Free fatty acid receptor 1 (FFA1) has been recognized to mediate insulin secretion, and pioglitazone has direct effects on glucose-stimulated insulin secretion in addition to the reversion of insulin resistance. In this study, we found that atorvastatin decreased potassium-stimulated insulin secretion and inhibited the expression of FFA1, PDX-1, and BETA2/NeuroD in INS-1 cells. Further study demonstrated that pioglitazone prevented the impairment of insulin secretion induced by atorvastatin and enhanced the expression of FFA1, PDX-1, and BETA2/NeuroD reduced by atorvastatin in INS-1 cells. In addition, the preventive effect of pioglitazone on atorvastatin-induced impairment of insulin secretion and the enhancement of the expression of PDX-1 and BETA2/NeuroD was abolished by knockdown of FFA1 using siRNA or the PLC inhibitor, U-73122, respectively. Ultimately, FFA1 may mediate the atorvastatin-induced pancreatic β-cell dysfunction and pioglitazone may ameliorate this deleterious effect through the upregulation of FFA1 expression.
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Affiliation(s)
- Kongbo Zhu
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Linglin Qian
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Yanshan Lin
- Department of Geriatrics, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Li An
- Department of Geriatrics, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Guangjian Mu
- Department of Geriatrics, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Genshan Ma
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
| | - Liqun Ren
- Department of Cardiology, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
- Department of Geriatrics, Zhongda Hospital, School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Nanjing 210009, China
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15
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Lee YS, Lee C, Choung JS, Jung HS, Jun HS. Glucagon-Like Peptide 1 Increases β-Cell Regeneration by Promoting α- to β-Cell Transdifferentiation. Diabetes 2018; 67:2601-2614. [PMID: 30257975 DOI: 10.2337/db18-0155] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 09/13/2018] [Indexed: 12/22/2022]
Abstract
Glucagon-like peptide 1 (GLP-1) can increase pancreatic β-cells, and α-cells could be a source for new β-cell generation. We investigated whether GLP-1 increases β-cells through α-cell transdifferentiation. New β-cells originating from non-β-cells were significantly increased in recombinant adenovirus expressing GLP-1 (rAd-GLP-1)-treated RIP-CreER;R26-YFP mice. Proliferating α-cells were increased in islets of rAd-GLP-1-treated mice and αTC1 clone 9 (αTC1-9) cells treated with exendin-4, a GLP-1 receptor agonist. Insulin+glucagon+ cells were significantly increased by rAd-GLP-1 or exendin-4 treatment in vivo and in vitro. Lineage tracing to label the glucagon-producing α-cells showed a higher proportion of regenerated β-cells from α-cells in rAd-GLP-1-treated Glucagon-rtTA;Tet-O-Cre;R26-YFP mice than rAd producing β-galactosidase-treated mice. In addition, exendin-4 increased the expression and secretion of fibroblast growth factor 21 (FGF21) in αTC1-9 cells and β-cell-ablated islets. FGF21 treatment of β-cell-ablated islets increased the expression of pancreatic and duodenal homeobox-1 and neurogenin-3 and significantly increased insulin+glucagon+ cells. Generation of insulin+glucagon+ cells by exendin-4 was significantly reduced in islets transfected with FGF21 small interfering RNA or islets of FGF21 knockout mice. Generation of insulin+ cells by rAd-GLP-1 treatment was significantly reduced in FGF21 knockout mice compared with wild-type mice. We suggest that GLP-1 has an important role in α-cell transdifferentiation to generate new β-cells, which might be mediated, in part, by FGF21 induction.
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Affiliation(s)
- Young-Sun Lee
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
| | - Changmi Lee
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
| | - Jin-Seung Choung
- College of Pharmacy and Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, Korea
| | - Hye-Seung Jung
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hee-Sook Jun
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea
- College of Pharmacy and Gachon Institute of Pharmaceutical Science, Gachon University, Incheon, Korea
- Gachon Medical Research Institute, Gil Hospital, Incheon, Korea
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16
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Gupta D, Jetton TL, LaRock K, Monga N, Satish B, Lausier J, Peshavaria M, Leahy JL. Temporal characterization of β cell-adaptive and -maladaptive mechanisms during chronic high-fat feeding in C57BL/6NTac mice. J Biol Chem 2017; 292:12449-12459. [PMID: 28487366 DOI: 10.1074/jbc.m117.781047] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/29/2017] [Indexed: 12/18/2022] Open
Abstract
The onset of type 2 diabetes is characterized by transition from successful to failed insulin secretory compensation to obesity-related insulin resistance and dysmetabolism. Energy-rich diets in rodents are commonly studied models of compensatory increases in both insulin secretion and β cell mass. However, the mechanisms of these adaptive responses are incompletely understood, and it is also unclear why these responses eventually fail. We measured the temporal trends of glucose homeostasis, insulin secretion, β cell morphometry, and islet gene expression in C57BL/6NTac mice fed a 60% high-fat diet (HFD) or control diet for up to 16 weeks. A 2-fold increased hyperinsulinemia was maintained for the first 4 weeks of HFD feeding and then further increased through 16 weeks. β cell mass increased progressively starting at 4 weeks, principally through nonproliferative growth. Insulin sensitivity was not significantly perturbed until 11 weeks of HFD feeding. Over the first 8 weeks, we observed two distinct waves of increased expression of β cell functional and prodifferentiation genes. This was followed by activation of the unfolded protein response at 8 weeks and overt β cell endoplasmic reticulum stress at 12-16 weeks. In summary, β cell adaptation to an HFD in C57BL/6NTac mice entails early insulin hypersecretion and a robust growth phase along with hyperexpression of related genes that begin well before the onset of observed insulin resistance. However, continued HFD exposure results in cessation of gene hyperexpression, β cell functional failure, and endoplasmic reticulum stress. These data point to a complex but not sustainable integration of β cell-adaptive responses to nutrient overabundance, obesity development, and insulin resistance.
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Affiliation(s)
- Dhananjay Gupta
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Thomas L Jetton
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Kyla LaRock
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Navjot Monga
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Basanthi Satish
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - James Lausier
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Mina Peshavaria
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446
| | - Jack L Leahy
- Division of Endocrinology, Diabetes, and Metabolism, University of Vermont, Burlington, Vermont 05446.
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17
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Yang Y, Gong L. Palmitoleate inhibits insulin transcription by activating the ERK1/2 pathway in rat pancreatic β-cells. Exp Ther Med 2017; 13:2805-2811. [PMID: 28587345 PMCID: PMC5450653 DOI: 10.3892/etm.2017.4344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 11/04/2016] [Indexed: 02/05/2023] Open
Abstract
The aim of the present study was to evaluate the effects of palmitoleate on insulin secretion and insulin mRNA levels, and to investigate the transcriptional regulation of insulin. INS-1 rat insulinoma cells were treated with palmitoleate in the presence of high glucose, and the amount of secreted insulin was measured via radioimmunoassay. Reverse transcription-quantitative polymerase chain reaction was performed to evaluate the mRNA levels of insulin and pancreatic and duodenal homeobox 1 (PDX1) under palmitoleate treatment. The levels of PDX1, peroxisome proliferator-activated receptor gamma (PPARG), extracellular signal-regulated kinase (ERK)1/2 and phosphorylated ERK1/2 were measured using western blot analysis. Low concentrations of palmitoleate significantly induced insulin secretion (P=0.024), whereas the mRNA levels of insulin and PDX1 were markedly reduced. However, the inhibitory effects were reversed with the addition of U0126, suggesting that the ERK1/2-mediated pathway may be the underlying mechanism responsible for palmitoleate-induced downregulation of insulin mRNA. Exposure of INS-1 cells to high glucose significantly increased the phosphorylation of ERK1/2 (P=0.039), which was further enhanced by palmitoleate (P=0.025). Exposure of INS-1 cells to high glucose significantly decreased PPARG (P=0.001), which was further decreased by the addition of palmitoleate. U0126 was able to reverse the palmitoleate-induced effects. In conclusion, the present study suggested that palmitoleate may induce insulin secretion and inhibit insulin mRNA expression in pancreatic β-cells.
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Affiliation(s)
- Yumei Yang
- Department of Endocrinology and Metabolism, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang 322000, P.R. China
| | - Liangliang Gong
- Department of Rheumatology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang 322000, P.R. China
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18
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Siglec-7 restores β-cell function and survival and reduces inflammation in pancreatic islets from patients with diabetes. Sci Rep 2017; 7:45319. [PMID: 28378743 PMCID: PMC5381285 DOI: 10.1038/srep45319] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/22/2017] [Indexed: 01/16/2023] Open
Abstract
Chronic inflammation plays a key role in both type 1 and type 2 diabetes. Cytokine and chemokine production within the islets in a diabetic milieu results in β-cell failure and diabetes progression. Identification of targets, which both prevent macrophage activation and infiltration into islets and restore β-cell functionality is essential for effective diabetes therapy. We report that certain Sialic-acid-binding immunoglobulin-like-lectins (siglecs) are expressed in human pancreatic islets in a cell-type specific manner. Siglec-7 was expressed on β-cells and down-regulated in type 1 and type 2 diabetes and in infiltrating activated immune cells. Over-expression of Siglec-7 in diabetic islets reduced cytokines, prevented β-cell dysfunction and apoptosis and reduced recruiting of migrating monocytes. Our data suggest that restoration of human Siglec-7 expression may be a novel therapeutic strategy targeted to both inhibition of immune activation and preservation of β-cell function and survival.
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19
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Insulinotropic effects of GPR120 agonists are altered in obese diabetic and obese non-diabetic states. Clin Sci (Lond) 2016; 131:247-260. [PMID: 27980130 DOI: 10.1042/cs20160545] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/13/2016] [Accepted: 12/15/2016] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptor 120 (GPR120) is a putative target for obesity and diabetes therapies. However, it remains controversial whether resident GPR120 plays a direct regulatory role in islet β-cell insulin secretion. The present study examined this issue in isolated rodent islets and rat β-cell line INS-1E, and assessed the role of GPR120 in islet insulin secretion in obese non-diabetic (OND) and diabetic states. GPR120 expression was detected in rodent islet β-cells. Docosahexaenoic acid (DHA) and synthetic GPR120 agonist GSK137647 (GSK) augmented insulin release from rat/mouse islets and INS-1E; DHA effects were partially mediated by GPR40. GPR120 knockdown and overexpression attenuated and enhanced DHA effects in INS-1E respectively. DHA and GSK improved postprandial hyperglycaemia of diabetic mice. Inhibition of calcium signalling in INS-1E reduced GPR120 activation-induced insulinotropic effects. The insulinotropic effects of DHA/GSK were amplified in OND rat islets, but diminished in diabetic rat islets. GPR120 and peroxisome proliferator-activated receptor γ (PPARγ) expression were elevated in OND islets and palmitic acid (PA)-treated INS-1E, but reduced in diabetic islets and high glucose-treated INS-1E. PPARγ activation increased GPR120 expression in rat islets and INS-1E. DHA and GSK induced protein kinase B (Akt)/extracellular signal-regulated kinase (ERK) phosphorylation in rodent islets and INS-1E, and these effects were altered in OND and diabetic states. Taken together, the present study indicates that (i) GPR120 activation has an insulinotropic influence on β-cells with the involvement of calcium signalling; (ii) GPR120 expression in β-cells and GPR120-mediated insulinotropic effects are altered in OND and diabetic states in distinct ways, and these alterations may be mediated by PPARγ.
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20
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Maganti AV, Tersey SA, Syed F, Nelson JB, Colvin SC, Maier B, Mirmira RG. Peroxisome Proliferator-activated Receptor-γ Activation Augments the β-Cell Unfolded Protein Response and Rescues Early Glycemic Deterioration and β Cell Death in Non-obese Diabetic Mice. J Biol Chem 2016; 291:22524-22533. [PMID: 27613867 DOI: 10.1074/jbc.m116.741694] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/05/2016] [Indexed: 12/11/2022] Open
Abstract
Type 1 diabetes is an autoimmune disorder that is characterized by a failure of the unfolded protein response in islet β cells with subsequent endoplasmic reticulum stress and cellular death. Thiazolidinediones are insulin sensitizers that activate the nuclear receptor PPAR-γ and have been shown to partially ameliorate autoimmune type 1 diabetes in humans and non-obese diabetic (NOD) mice. We hypothesized that thiazolidinediones reduce β cell stress and death independently of insulin sensitivity. To test this hypothesis, female NOD mice were administered pioglitazone during the pre-diabetic phase and assessed for insulin sensitivity and β cell function relative to controls. Pioglitazone-treated mice showed identical weight gain, body fat distribution, and insulin sensitivity compared with controls. However, treated mice showed significantly improved glucose tolerance with enhanced serum insulin levels, reduced β cell death, and increased β cell mass. The effect of pioglitazone was independent of actions on T cells, as pancreatic lymph node T cell populations were unaltered and T cell proliferation was unaffected by pioglitazone. Isolated islets of treated mice showed a more robust unfolded protein response, with increases in Bip and ATF4 and reductions in spliced Xbp1 mRNA. The effect of pioglitazone appears to be a direct action on β cells, as islets from mice treated with pioglitazone showed reductions in PPAR-γ (Ser-273) phosphorylation. Our results demonstrate that PPAR-γ activation directly improves β cell function and survival in NOD mice by enhancing the unfolded protein response and suggest that blockade of PPAR-γ (Ser-273) phosphorylation may prevent type 1 diabetes.
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Affiliation(s)
- Aarthi V Maganti
- From the Department of Cellular and Integrative Physiology.,Center for Diabetes and Metabolic Diseases
| | - Sarah A Tersey
- Center for Diabetes and Metabolic Diseases.,Department of Pediatrics and the Herman B Wells Center
| | - Farooq Syed
- Department of Pediatrics and the Herman B Wells Center
| | | | - Stephanie C Colvin
- Center for Diabetes and Metabolic Diseases.,Department of Pediatrics and the Herman B Wells Center
| | - Bernhard Maier
- Center for Diabetes and Metabolic Diseases.,Department of Pediatrics and the Herman B Wells Center
| | - Raghavendra G Mirmira
- From the Department of Cellular and Integrative Physiology, .,Center for Diabetes and Metabolic Diseases.,Department of Pediatrics and the Herman B Wells Center.,Department of Medicine, and.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202 and.,Indiana Biosciences Research Institute, Indianapolis, Indiana 46202
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21
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Güven C, Dal F, Aydoğan Ahbab M, Taskin E, Ahbab S, Adin Çinar S, Sırma Ekmekçi S, Güleç Ç, Abacı N, Akçakaya H. Low dose monoethyl phthalate (MEP) exposure triggers proliferation by activating PDX-1 at 1.1B4 human pancreatic beta cells. Food Chem Toxicol 2016; 93:41-50. [DOI: 10.1016/j.fct.2016.04.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 04/24/2016] [Accepted: 04/26/2016] [Indexed: 10/21/2022]
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22
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Li L, Li T, Zhang Y, Pan Z, Wu B, Huang X, Zhang Y, Mei Y, Ge L, Shen G, Ge RS, Zhu D, Lou Y. Peroxisome proliferator-activated receptorβ/δ activation is essential for modulating p-Foxo1/Foxo1 status in functional insulin-positive cell differentiation. Cell Death Dis 2015; 6:e1715. [PMID: 25855963 PMCID: PMC4650555 DOI: 10.1038/cddis.2015.88] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 02/26/2015] [Accepted: 03/02/2015] [Indexed: 11/25/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) participate in energy homeostasis and play essential roles in diabetes therapy through their effects on non-pancreas tissues. Pathological microenvironment may influence the metabolic requirements for the maintenance of stem cell differentiation. Accordingly, understanding the mechanisms of PPARs on pancreatic β-cell differentiation may be helpful to find the underlying targets of disrupted energy homeostasis under the pancreatic disease condition. PPARs are involved in stem cell differentiation via mitochondrial oxidative phosphorylation, but the subtype member activation and the downstream regulation in functional insulin-positive (INS+) cell differentiation remain unclear. Here, we show a novel role of PPARβ/δ activation in determining INS+ cell differentiation and functional maturation. We found PPARβ/δ expression selectively upregulated in mouse embryonic pancreases or stem cells-derived INS+ cells at the pancreatic mature stage in vivo and in vitro. Strikingly, given the inefficiency of generating INS+ cells in vitro, PPARβ/δ activation displayed increasing mouse and human ES cell-derived INS+ cell numbers and insulin secretion. This phenomenon was closely associated with the forkhead box protein O1 (Foxo1) nuclear shuttling, which was dependent on PPARβ/δ downstream PI3K/Akt signaling transduction. The present study reveals the essential role of PPARβ/δ activation on p-Foxo1/Foxo1 status, and in turn, determining INS+ cell generation and insulin secretion via affecting pancreatic and duodenal homeobox-1 expression. The results demonstrate the underlying mechanism by which PPARβ/δ activation promotes functional INS+ cell differentiation. It also provides potential targets for anti-diabetes drug discovery and hopeful clinical applications in human cell therapy.
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Affiliation(s)
- L Li
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - T Li
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Y Zhang
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Z Pan
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - B Wu
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - X Huang
- Cardiovascular Key Laboratory of Zhejiang Province, The 2nd Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Y Zhang
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Y Mei
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - L Ge
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - G Shen
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - R-s Ge
- 1] The Population Council at the Rockefeller University, New York, NY 10021, USA [2] Institute of Reproductive Biomedicine, the 2nd Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - D Zhu
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Y Lou
- Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, Key Innovation Team for Stem Cell Translational Medicine of Cardiovascular Disease of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
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23
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Hsu WH, Pan TM. A novel PPARgamma agonist monascin's potential application in diabetes prevention. Food Funct 2015; 5:1334-40. [PMID: 24752777 DOI: 10.1039/c3fo60575b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Edible fungi of the Monascus species have been used as traditional Chinese medicine in eastern Asia for several centuries. Monascus-fermented products possess a number of functional secondary metabolites, including the anti-inflammatory pigments monascin and ankaflavin. Monascin has been shown to prevent or ameliorate several conditions, including hypercholesterolemia, hyperlipidemia, diabetes, and obesity. Recently, monascin has been shown to improve hyperglycemia, attenuate oxidative stress, inhibit insulin resistance, and suppress inflammatory cytokine production. In our recent study, we have found that monascin is a peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist. The PPARgamma agonist activity had been investigated and its exerted benefits are inhibition of inflammation in methylglyoxal (MG)-treated rats, prevention of pancreas impairment causing advanced glycation endproducts (AGEs), promotion of insulin expression in vivo and in vitro, and attenuated carboxymethyllysine (CML)-induced hepatic stellate cell (HSC) activation in the past several years. Moreover, our studies also demonstrated that monascin also activated nuclear factor-erythroid 2-related factor 2 (Nrf2) in pancreatic RIN-m5F cell line thereby invading methylglyoxal induced pancreas dysfunction. In this review, we focus on the chemo-preventive properties of monascin against metabolic syndrome through PPARgamma and Nrf2 pathways.
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Affiliation(s)
- Wei-Hsuan Hsu
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.
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Xia CQ, Zhang P, Li S, Yuan L, Xia T, Xie C, Clare-Salzler MJ. C-Abl inhibitor imatinib enhances insulin production by β cells: c-Abl negatively regulates insulin production via interfering with the expression of NKx2.2 and GLUT-2. PLoS One 2014; 9:e97694. [PMID: 24835010 PMCID: PMC4023982 DOI: 10.1371/journal.pone.0097694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 04/23/2014] [Indexed: 12/16/2022] Open
Abstract
Chronic myelogenous leukemia patients treated with tyrosine kinase inhibitor, Imatinib, were shown to have increased serum levels of C-peptide. Imatinib specifically inhibits the tyrosine kinase, c-Abl. However, the mechanism of how Imatinib treatment can lead to increased insulin level is unclear. Specifically, there is little investigation into whether Imatinib directly affects β cells to promote insulin production. In this study, we showed that Imatinib significantly induced insulin expression in both glucose-stimulated and resting β cells. In line with this finding, c-Abl knockdown by siRNA and overexpression of c-Abl markedly enhanced and inhibited insulin expression in β cells, respectively. Unexpectedly, high concentrations of glucose significantly induced c-Abl expression, suggesting c-Abl may play a role in balancing insulin production during glucose stimulation. Further studies demonstrated that c-Abl inhibition did not affect the major insulin gene transcription factor, pancreatic and duodenal homeobox-1 (PDX-1) expression. Of interest, inhibition of c-Abl enhanced NKx2.2 and overexpression of c-Abl in β cells markedly down-regulated NKx2.2, which is a positive regulator for insulin gene expression. Additionally, we found that c-Abl inhibition significantly enhanced the expression of glucose transporter GLUT2 on β cells. Our study demonstrates a previously unrecognized mechanism that controls insulin expression through c-Abl-regulated NKx2.2 and GLUT2. Therapeutic targeting β cell c-Abl could be employed in the treatment of diabetes or β cell tumor, insulinoma.
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Affiliation(s)
- Chang-Qing Xia
- Department of Hematology, Xuanwu Hospital, Capital Medical University, Bejing, China
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Pengcheng Zhang
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
| | - Shiwu Li
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
| | - Lihui Yuan
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
| | - Tina Xia
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
| | - Chao Xie
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
| | - Michael J. Clare-Salzler
- Department of Pathology, Immunology and Laboratory Medicine, Diabetes Center of Excellence, University of Florida, Gainesville, Florida, United States of America
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Chen M, Hu C, Zhang R, Jiang F, Wang J, Peng D, Tang S, Sun X, Yan J, Luo Y, Bao Y, Jia W. Association of PAX4 genetic variants with oral antidiabetic drugs efficacy in Chinese type 2 diabetes patients. THE PHARMACOGENOMICS JOURNAL 2014; 14:488-92. [PMID: 24752311 DOI: 10.1038/tpj.2014.18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/14/2014] [Accepted: 02/26/2014] [Indexed: 11/09/2022]
Abstract
The aim of this study was to investigate the association of PAX4 variants with therapeutic effect of oral antidiabetic drugs in Chinese type 2 diabtes mellitus (T2DM) patients. A total of 209 newly diagnosed T2DM patients were randomly assigned to treatment with repaglinide or rosiglitazone for 48 weeks, and the therapeutic effects were compared. In the rosiglitazone cohort, rs6467136 GA+AA carriers showed greater decrease in 2-h glucose levels (P=0.0063) and higher cumulative attainment rates of target 2-h glucose levels (Plog rank=0.0093) than GG homozygotes. In the subgroup with defective β-cell function, rs6467136 GA+AA carriers exhibited greater decrements of 2-h glucose level and improvement of homeostasis model assessment of insulin resistance (P=0.0143). Moreover, GA+AA carriers were more likely to attain the target fasting and 2-h glucose level (Plog rank=0.0091 and 0.007, respectively). However, these single-nucleotide polymorphisms showed no effect on repaglinide efficacy. In conclusion, PAX4 variant rs6467136 was associated with the therapeutic effect of rosiglitazone in Chinese T2DM patients.
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Affiliation(s)
- M Chen
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - C Hu
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - R Zhang
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - F Jiang
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - J Wang
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - D Peng
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - S Tang
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - X Sun
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - J Yan
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - Y Luo
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - Y Bao
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
| | - W Jia
- Department of Endocrinology and Metabolism, Shanghai Clinical Center for Diabetes, Shanghai Key Clinical Center for Metabolic Disease, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Diabetes Institute, Shanghai, China
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Hsu WH, Pan TM. Treatment of metabolic syndrome with ankaflavin, a secondary metabolite isolated from the edible fungus Monascus spp. Appl Microbiol Biotechnol 2014; 98:4853-63. [DOI: 10.1007/s00253-014-5716-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 03/19/2014] [Accepted: 03/21/2014] [Indexed: 12/31/2022]
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Cheng AS, Cheng YH, Chang TL. Resveratrol protects RINm5F pancreatic cells from methylglyoxal-induced apoptosis. J Funct Foods 2013. [DOI: 10.1016/j.jff.2013.07.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Lee BH, Lee CC, Cheng YH, Chang WC, Hsu WH, Wu SC. Graptopetalum paraguayense and resveratrol ameliorates carboxymethyllysine (CML)-induced pancreas dysfunction and hyperglycemia. Food Chem Toxicol 2013; 62:492-8. [PMID: 24036142 DOI: 10.1016/j.fct.2013.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 08/27/2013] [Accepted: 09/06/2013] [Indexed: 01/02/2023]
Abstract
Hyperglycemia is associated with advanced glycation end products (AGEs). Recently, AGEs were found to cause pancreatic damage, oxidative stress, and hyperglycemia through the AGE receptor. Carboxymethyllysine (CML) is an AGE but whether it induces pancreatic dysfunction remains unclear. Graptopetalum paraguayense, a vegetable consumed in Taiwan, has been used in folk medicine and is an antioxidant that protects against liver damage. We investigated the protective properties of G. paraguayense 95% ethanol extracts (GPEs) against CML-induced pancreatic damage. The results indicated that resveratrol, GPE, and gallic acid (the active compound of GPE) increased insulin synthesis via upregulation of pancreatic peroxisome proliferator activated-receptor-γ (PPARγ) and pancreatic-duodenal homeobox-1 (PDX-1) but inhibited the expression of CML-mediated CCAAT/enhancer binding protein-β (C/EBPβ), a negative regulator of insulin production. Moreover, resveratrol and GPE also strongly activated nuclear factor-erythroid 2-related factor 2 (Nrf2) to attenuate oxidative stress and improve insulin sensitivity in the liver and muscle of CML-injected C57BL/6 mice and resulted in reduced blood glucose levels. Taken together, these findings suggested that GPE and gallic acid could potentially be used as a food supplement to protect against pancreatic damage and the development of diabetes.
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Affiliation(s)
- Bao-Hong Lee
- Department of Food Science, National Chiayi University, Taiwan, ROC.
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Eldor R, DeFronzo RA, Abdul-Ghani M. In vivo actions of peroxisome proliferator-activated receptors: glycemic control, insulin sensitivity, and insulin secretion. Diabetes Care 2013; 36 Suppl 2:S162-74. [PMID: 23882042 PMCID: PMC3920780 DOI: 10.2337/dcs13-2003] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Roy Eldor
- Diabetes Division, Department of Medicine, University of Texas Health Science Center, San Antonio, Texas, USA
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Hsu WH, Lee BH, Li CH, Hsu YW, Pan TM. Monascin and AITC attenuate methylglyoxal-induced PPARγ phosphorylation and degradation through inhibition of the oxidative stress/PKC pathway depending on Nrf2 activation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:5996-6006. [PMID: 23731245 DOI: 10.1021/jf401197r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Abnormal cellular accumulation of the dicarbonyl metabolite methylglyoxal (MG) results in cell damage, inflammation, and oxidative stress. It is also associated with increased protein linkage to form advanced glycation end products (AGEs) or induce DNA strand breaks. The association between peroxisome proliferator-activated receptor-γ (PPARγ) and nuclear factor-erythroid 2-related factor 2 (Nrf2) is unclear. This study investigated Nrf2 activator protection against PPARγ phosphorylation and degradation to maintain pancreatic function. MG was used at a noncytotoxic concentration (200 μM) to induce protein kinase C (PKC) and PPARγ phosphorylation in pancreatic RINm5F cells. For in vivo studies, MG (60 mg/kg bw) was intraperitoneally (IP) injected into Balb/C mice for 28 d to induce pancreas damage, at which point we investigated the effect of monascin protection (PPARγ and Nrf2 activator), rosiglitazone (PPARγ activator), allyl isothiocyanate (AITC; Nrf2 activator), or N-acetylcysteine (NAC) on pancreatic function. The in vitro and in vivo results indicated that MG leads to marked PPARγ phosphorylation (serine 82); this effect led to reduction in pancreatic and duodenal homeobox-1 (PDX-1), glucokinase (GCK), and insulin expression. However, monascin and rosiglitazone may protect PPARγ degradation by elevating PDX-1, GCK, and as a result, insulin expression. Monascin and AITC can attenuate PKC activation to suppress PPARγ phosphorylation caused by oxidative stress through the Nrf2 pathway. Similarly, the N-acetylcysteine (NAC) antioxidant also improved oxidative stress and pancreatic function. This study examined whether MG caused impairment of PDX-1, GCK, and insulin through PPARγ phosphorylation and degradation. MG and AGE accumulation improved on Nrf2 activation, thereby protecting against pancreas damage. Taken together, PPARγ activation maintained pancreatic PDX-1, GCK, and insulin expression levels to regulate blood glucose levels.
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Affiliation(s)
- Wei-Hsuan Hsu
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University , No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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Gupta D, Leahy AA, Monga N, Peshavaria M, Jetton TL, Leahy JL. Peroxisome proliferator-activated receptor γ (PPARγ) and its target genes are downstream effectors of FoxO1 protein in islet β-cells: mechanism of β-cell compensation and failure. J Biol Chem 2013; 288:25440-25449. [PMID: 23788637 DOI: 10.1074/jbc.m113.486852] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The molecular mechanisms and signaling pathways that drive islet β-cell compensation and failure are not fully resolved. We have used in vitro and in vivo systems to show that FoxO1, an integrator of metabolic stimuli, inhibits PPARγ expression in β-cells, thus transcription of its target genes (Pdx1, glucose-dependent insulinotropic polypeptide (GIP) receptor, and pyruvate carboxylase) that are important regulators of β-cell function, survival, and compensation. FoxO1 inhibition of target gene transcription is normally relieved when upstream activation induces its translocation from the nucleus to the cytoplasm. Attesting to the central importance of this pathway, islet expression of PPARγ and its target genes was enhanced in nondiabetic insulin-resistant rats and markedly reduced with diabetes induction. Insight into the impaired PPARγ signaling with hyperglycemia was obtained with confocal microscopy of pancreas sections that showed an intense nuclear FoxO1 immunostaining pattern in the β-cells of diabetic rats in contrast to the nuclear and cytoplasmic FoxO1 in nondiabetic rats. These findings suggest a FoxO1/PPARγ-mediated network acting as a core component of β-cell adaptation to metabolic stress, with failure of this response from impaired FoxO1 activation causing or exacerbating diabetes.
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Affiliation(s)
- Dhananjay Gupta
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Averi A Leahy
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Navjot Monga
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Mina Peshavaria
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Thomas L Jetton
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405
| | - Jack L Leahy
- From the Division of Endocrinology, Diabetes, and Metabolism and the Department of Medicine, University of Vermont, Burlington, Vermont 05405.
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Lee BH, Hsu WH, Hsu YW, Pan TM. Dimerumic acid protects pancreas damage and elevates insulin production in methylglyoxal-treated pancreatic RINm5F cells. J Funct Foods 2013. [DOI: 10.1016/j.jff.2012.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Quercetin Preserves β -Cell Mass and Function in Fructose-Induced Hyperinsulinemia through Modulating Pancreatic Akt/FoxO1 Activation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:303902. [PMID: 23533474 PMCID: PMC3600179 DOI: 10.1155/2013/303902] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 01/26/2013] [Accepted: 01/26/2013] [Indexed: 12/20/2022]
Abstract
Fructose-induced hyperinsulinemia is associated with insulin compensative secretion and predicts the onset of type 2 diabetes. In this study, we investigated the preservation of dietary flavonoid quercetin on pancreatic β-cell mass and function in fructose-treated rats and INS-1 β-cells. Quercetin was confirmed to reduce serum insulin and leptin levels and blockade islet hyperplasia in fructose-fed rats. It also prevented fructose-induced β-cell proliferation and insulin hypersecretion in INS-1 β-cells. High fructose increased forkhead box protein O1 (FoxO1) expressions in vivo and in vitro, which were reversed by quercetin. Quercetin downregulated Akt and FoxO1 phosphorylation in fructose-fed rat islets and increased the nuclear FoxO1 levels in fructose-treated INS-1 β-cells. The elevated Akt phosphorylation in fructose-treated INS-1 β-cells was also restored by quercetin. Additionally, quercetin suppressed the expression of pancreatic and duodenal homeobox 1 (Pdx1) and insulin gene (Ins1 and Ins2) in vivo and in vitro. In fructose-treated INS-1 β-cells, quercetin elevated the reduced janus kinase 2/signal transducers and activators of transcription 3 (Jak2/Stat3) phosphorylation and suppressed the increased suppressor of cytokine signaling 3 (Socs3) expression. These results demonstrate that quercetin protects β-cell mass and function under high-fructose induction through improving leptin signaling and preserving pancreatic Akt/FoxO1 activation.
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PPARγ activation attenuates glycated-serum induced pancreatic beta-cell dysfunction through enhancing Pdx1 and Mafa protein stability. PLoS One 2013; 8:e56386. [PMID: 23424659 PMCID: PMC3570423 DOI: 10.1371/journal.pone.0056386] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 01/10/2013] [Indexed: 12/31/2022] Open
Abstract
Pancreatic-duodenal homeobox-1 (Pdx1) and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (Mafa) play important roles in sustaining the pancreatic beta-cell differentiation phenotype. Peroxisome proliferator-activated receptor-γ (PPARγ) is also a regulator of cell differentiation. Our previous study revealed that glycated serum (GS) causes beta-cell dedifferentiation by down-regulating beta-cell specific genes, such as insulin and Pdx1. Here, we show that GS enhanced the cellular accumulation of ubiquitin-conjugated proteins, including Pdx1 and Mafa, in pancreatic beta-cells. Pharmacologic inhibition of proteolytic activity restored the protein levels of Pdx1 and Mafa, whereas inhibition of de novo protein synthesis accelerated their degradation. These findings suggest that both Pdx1 and Mafa are regulated at the post-transcriptional level. We further show that activation of PPARγ could restore GS-induced reduction of Pdx1 and Mafa protein levels, leading to improved insulin secretion and synthesis. Moreover, ectopic expression of Bcl-xl, a mitochondrial regulator, also restored Pdx1 and Mafa protein levels, linking mitochondrial function to Pdx1 and Mafa stability. Taken together, our results identify a key role of PPARγ in regulating pancreatic beta-cell function by improving the stability of Pdx1 and Mafa proteins.
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Kim HS, Hwang YC, Koo SH, Park KS, Lee MS, Kim KW, Lee MK. PPAR-γ activation increases insulin secretion through the up-regulation of the free fatty acid receptor GPR40 in pancreatic β-cells. PLoS One 2013; 8:e50128. [PMID: 23372643 PMCID: PMC3553172 DOI: 10.1371/journal.pone.0050128] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 10/16/2012] [Indexed: 11/18/2022] Open
Abstract
Background It has been reported that peroxisome proliferator-activated receptor (PPAR)-γ and their synthetic ligands have direct effects on pancreatic β-cells. We investigated whether PPAR-γ activation stimulates insulin secretion through the up-regulation of GPR40 in pancreatic β-cells. Methods Rat insulinoma INS-1 cells and primary rat islets were treated with rosiglitazone (RGZ) and/or adenoviral PPAR-γ overexpression. OLETF rats were treated with RGZ. Results PPAR-γ activation with RGZ and/or adenoviral PPAR-γ overexpression increased free fatty acid (FFA) receptor GPR40 expression, and increased insulin secretion and intracellular calcium mobilization, and was blocked by the PLC inhibitors, GPR40 RNA interference, and GLUT2 RNA interference. As a downstream signaling pathway of intracellular calcium mobilization, the phosphorylated levels of CaMKII and CREB, and the downstream IRS-2 and phospho-Akt were significantly increased. Despite of insulin receptor RNA interference, the levels of IRS-2 and phospho-Akt was still maintained with PPAR-γ activation. In addition, the β-cell specific gene expression, including Pdx-1 and FoxA2, increased in a GPR40- and GLUT2-dependent manner. The levels of GPR40, phosphorylated CaMKII and CREB, and β-cell specific genes induced by RGZ were blocked by GW9662, a PPAR-γ antagonist. Finally, PPAR-γ activation up-regulated β-cell gene expressions through FoxO1 nuclear exclusion, independent of the insulin signaling pathway. Based on immunohistochemical staining, the GLUT2, IRS-2, Pdx-1, and GPR40 were more strongly expressed in islets from RGZ-treated OLETF rats compared to control islets. Conclusion These observations suggest that PPAR-γ activation with RGZ and/or adenoviral overexpression increased intracellular calcium mobilization, insulin secretion, and β-cell gene expression through GPR40 and GLUT2 gene up-regulation.
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Affiliation(s)
- Hyo-Sup Kim
- Division of Endocrinology and Metabolism, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - You-Cheol Hwang
- Division of Endocrinology and Metabolism, Department of Medicine, Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Seoul, Korea
| | - Seung-Hoi Koo
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyong Soo Park
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Myung-Shik Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kwang-Won Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Moon-Kyu Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- * E-mail:
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Hsu WH, Lu SS, Lee BH, Hsu YW, Pan TM. Monacolin K and monascin attenuated pancreas impairment and hyperglycemia induced by advanced glycation endproducts in BALB/c mice. Food Funct 2013; 4:1742. [DOI: 10.1039/c3fo60268k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Lee BH, Hsu WH, Chang YY, Kuo HF, Hsu YW, Pan TM. Ankaflavin: a natural novel PPARγ agonist upregulates Nrf2 to attenuate methylglyoxal-induced diabetes in vivo. Free Radic Biol Med 2012; 53:2008-16. [PMID: 23022408 DOI: 10.1016/j.freeradbiomed.2012.09.025] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 08/04/2012] [Accepted: 09/15/2012] [Indexed: 12/15/2022]
Abstract
Ankaflavin (AK) is an active compound having anti-inflammatory, anti-cancer, antiatherosclerotic, and hypolipidemic effects. We have previously reported that AK acts as an antioxidant and antidiabetic drug; however, the mechanism by which AK prevents diabetes remains unknown. Hyperglycemia is associated with protein glycation, which produces advanced glycation end-products (AGEs). Methylglyoxal (MG)-a metabolite of carbohydrates-is believed to cause insulin resistance by inducing inflammation and pancreas damage. In this work, diabetes was induced in Wistar rats (4 weeks of age) by treating them with MG (600 mg/kg bw) for 4 weeks. We observed that AK (10mg/kg bw) exerted peroxisome proliferator-activated receptor-γ (PPARγ) agonist activity, thereby enhancing insulin sensitivity (as indicated by hepatic GLUT2 translocation, PTP1B suppression, and glucose uptake) by downregulating blood glucose and upregulating pancreatic and duodenal homeobox-1 and Maf-A expression and increasing insulin production in MG-induced rats. However, these effects were abolished by the administration of GW9662 (PPARγ antagonist), but the expression of hepatic heme oxygenase-1 (HO-1) and glutamate-cysteine ligase (GCL) was not suppressed in MG-induced rats. Therefore, the nuclear factor erythroid-related factor-2 (Nrf2) activation was investigated. AK did not affect hepatic Nrf2 mRNA or protein expression but significantly increased Nrf2 phosphorylation (serine 40), which was accompanied by increased transcriptional activation of hepatic HO-1 and GCL. These data indicated that AK protected rats from oxidative stress resulting from MG-induced insulin resistance. In contrast, these effects were not detected when the rats were treated with the antidiabetic drug rosiglitazone (10mg/kg bw). Moreover, we found that AK did not inhibit the generation of AGEs in vitro; however, the glutathione (GSH) levels in liver and pancreas of MG-induced rats were elevated in rats administered AK. Therefore, we believe that GSH may lower the MG level, which attenuates the formation of AGEs in the serum, kidney, liver, and pancreas of MG-induced rats. We also found that AK treatment reduced the production of inflammatory factors, such as tumor necrosis factor-α and interleukin-1β. Taken together, the results of our mechanistic study of MG-induced rats suggest that the protective effects of AK against diabetes are mediated by the upregulation of the signaling pathway of Nrf2, which enhances antioxidant activity and serves as a PPARγ agonist to enhance insulin sensitivity.
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MESH Headings
- Anilides/pharmacology
- Animals
- Anti-Inflammatory Agents/pharmacology
- Anti-Inflammatory Agents/therapeutic use
- Blood Glucose
- Cytokines/metabolism
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/drug therapy
- Flavins/pharmacology
- Flavins/therapeutic use
- Gene Expression/drug effects
- Gene Expression Regulation
- Glycation End Products, Advanced/blood
- Glycation End Products, Advanced/metabolism
- Heme Oxygenase-1/genetics
- Heme Oxygenase-1/metabolism
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Insulin/blood
- Insulin Resistance
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/metabolism
- Liver/drug effects
- Liver/enzymology
- Liver/physiopathology
- Male
- NF-E2-Related Factor 2/genetics
- NF-E2-Related Factor 2/metabolism
- Oxidative Stress/drug effects
- PPAR gamma/agonists
- PPAR gamma/antagonists & inhibitors
- PPAR gamma/metabolism
- Pancreas/drug effects
- Pancreas/metabolism
- Pancreas/physiopathology
- Phosphorylation
- Protein Processing, Post-Translational
- Pyruvaldehyde
- Rats
- Rats, Wistar
- Receptor for Advanced Glycation End Products
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Up-Regulation/drug effects
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Affiliation(s)
- Bao-Hong Lee
- Department of Biochemical Science & Technology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
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Welters HJ, El Ouaamari A, Kawamori D, Meyer J, Hu J, Smith DM, Kulkarni RN. Rosiglitazone promotes PPARγ-dependent and -independent alterations in gene expression in mouse islets. Endocrinology 2012; 153:4593-9. [PMID: 22807489 PMCID: PMC3512010 DOI: 10.1210/en.2012-1243] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The glitazone class of insulin-sensitizing agents act, in part, by the activation of peroxisome proliferator-activated receptor (PPAR)-γ in adipocytes. However, it is unclear whether the expression of PPARγ in the islets is essential for their potential β-cell-sparing properties. To investigate the in vivo effects of rosiglitazone on β-cell biology, we used an inducible, pancreatic and duodenal homeobox-1 enhancer element-driven, Cre recombinase to knockout PPARγ expression specifically in adult β-cells (PPARgKO). Subjecting the PPARgKO mice to a chow diet led to virtually undetectable changes in glucose or insulin sensitivity, which was paralleled by minimal changes in islet gene expression. Similarly, challenging the mutant mice with a high-fat diet and treatment with rosiglitazone did not alter insulin sensitivity, glucose-stimulated insulin secretion, islet size, or proliferation in the knockout mice despite PPARγ-dependent and -independent changes in islet gene expression. These data suggest that PPARγ expression in the β-cells is unlikely to be directly essential for normal β-cell function or the insulin-sensitizing actions of rosiglitazone.
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Affiliation(s)
- Hannah J Welters
- Peninsula College of Medicine and Dentistry, University of Exeter, Exeter EX2 5DW, United Kingdom.
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Liang J, Leung KK, Lam SY, Leung PS. Combined treatment with a dipeptidyl peptidase-IV inhibitor (sitagliptin) and an angiotensin II type 1 receptor blocker (losartan) promotes islet regeneration via enhanced differentiation of pancreatic progenitor cells. Diabetes Obes Metab 2012; 14:842-51. [PMID: 22519909 DOI: 10.1111/j.1463-1326.2012.01612.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM The existence of pancreatic progenitor cells (PPCs) with differentiation capacity in the adult pancreas has rendered that promotion of islet regeneration is feasible. The dipeptidyl peptidase-IV inhibitor sitagliptin and the angiotensin II type 1 receptor (AT(1) receptor) blocker losartan have a common target action in the pancreata. Thus, we evaluated the synergistic/additive effects of these two drugs on the differentiation of islet progenitors. METHODS The acute and chronic effects of sitagliptin and losartan, individually or in combination, on islet regeneration in vivo were investigated by using a streptozotocin-induced type 1 diabetes mouse model. Their effects were also examined on an in vitro PPCs model derived from human foetal pancreas. RESULTS A chronic combination treatment enhanced glucose tolerance in diabetic mice associated with an increased ratio of β cells to islet; an acute combination treatment resulted in a marked increase in the production of neurogenin 3 (NGN3(+)) cells in proximity to CK7(+) ductal cell and an increased presence of insulin(+) /CK7(+) cells. The in vitro study revealed that a combination treatment significantly enhanced mRNA expression of NGN3, NKX6.1 and PDX-1 during PPCs differentiation into human islet-like cell clusters (ICCs). Despite no apparent changes in insulin release, the combined treatment resulted in increasing production of peroxisome proliferator-activated receptor γ (PPARγ) during PPC differentiation. CONCLUSIONS These data indicate that combined sitagliptin-losartan treatment can improve islet function by promoting the differentiation of PPCs into ICCs, perhaps via a mechanism involving PPARγ production, and could thereby, contribute to islet regeneration.
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Affiliation(s)
- J Liang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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40
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Castell-Auví A, Cedó L, Pallarès V, Blay MT, Pinent M, Motilva MJ, Garcia-Vallvé S, Pujadas G, Maechler P, Ardévol A. Procyanidins modify insulinemia by affecting insulin production and degradation. J Nutr Biochem 2012; 23:1565-72. [PMID: 22444499 DOI: 10.1016/j.jnutbio.2011.10.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 09/19/2011] [Accepted: 10/14/2011] [Indexed: 11/30/2022]
Abstract
Previous studies from our research group have suggested that procyanidins modify glycemia and insulinemia. The aim of this work was to evaluate the effects of procyanidins on β-cell functionality in a nonpathological system. Four groups of healthy rats were studied. The animals were given daily acute doses of grape seed procyanidin extract (GSPE) for different time periods and at different daily amounts. A β-cell line (INS-1E) was treated with 25 mg GSPE/L for 24 h to identify possible mechanisms of action for the procyanidins. In vivo experiments showed that different doses of GSPE affected insulinemia in different ways by modifying β-cell functionality and/or insulin degradation. The islets isolated from rats that were treated with 25 mg GSPE/kg of body weight for 45 days exhibited a limited response to glucose stimulation. In addition, insulin gene expression, insulin synthesis and expression of genes related to insulin secretion were all down-regulated. In vitro studies revealed that GSPE decreased the ability of β-cells to secrete insulin in response to glucose. GSPE increased glucose uptake in β-cells under high-glucose conditions but impaired glucose-induced mitochondrial hyperpolarization, decreased adenosine triphosphate (ATP) synthesis and altered cellular membrane potentials. GSPE also modified Glut2, glucokinase and Ucp2 gene expression as well as altered the expression of hepatic insulin-degrading enzyme (Ide), thereby altering insulin degradation. At some doses, procyanidins changed β-cell functionality by modifying insulin synthesis, secretion and degradation under nonpathological conditions. Membrane potentials and Ide provide putative targets for procyanidins to induce these effects.
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Affiliation(s)
- Anna Castell-Auví
- Departament de Bioquímica i Biotecnologia, Universitat Rovira i Virgili, Tarragona, Spain
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Abstract
The aim of the present study was to determine the effects of a cafeteria diet on the function and apoptosis of the pancreas, and the activity and expression of the insulin-degrading enzyme (IDE). Female Wistar rats were fed either with a cafeteria diet or a control diet for 17 weeks, and blood and tissues were then collected for analysis. The cafeteria diet-treated rats had higher plasma insulin and C-peptide levels (P<0·05), showing increased insulin secretion by the pancreas. Insulin protein and gene expression levels were higher in the pancreas of obese rats, as was its transcriptional controller, pancreatic duodenal homeobox 1 (P<0·05). Feeding a cafeteria diet down-regulated the gene expression of the anti-apoptotic marker B-cell/lymphoma 2 (BCL2), and up-regulated the protein levels of BCL2-associated X protein, a pro-apoptotic marker (P<0·05). The cafeteria diet caused lipid accumulation in the pancreas and modified the expression of key genes that control lipid metabolism. To assay whether insulin clearance was also modified, we checked the activity of the IDE, one of the enzymes responsible for insulin clearance. We found increased liver IDE activity (P<0·05) in the cafeteria diet-fed animals, which could, in part, be due to an up-regulation of its gene expression. Conversely, IDE gene expression was unmodified in the kidney and adipose tissue; although when the adipose tissue weight was considered, the insulin clearance potential was higher in the cafeteria diet-treated rats. In conclusion, treatment with a cafeteria diet for 17 weeks in rats mimicked a pre-diabetic state, with ectopic lipid accumulation in the pancreas, and increased the IDE-mediated insulin clearance capability.
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42
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The Roles of PPARs in the Fetal Origins of Metabolic Health and Disease. PPAR Res 2011; 2008:459030. [PMID: 18288289 PMCID: PMC2234254 DOI: 10.1155/2008/459030] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 08/29/2007] [Indexed: 01/01/2023] Open
Abstract
Beyond the short-term effects on fertility, there is increasing evidence that obesity or the consumption of an inappropriate diet by the mother during pregnancy adversely affects the long-term health of her offspring. PPAR and RXR isotypes are widely expressed in reproductive tissues and in the developing fetus. Through their interactions with fatty acids, they may mediate adaptive responses to the changes in the maternal diet. In the maturing follicle, PPAR-γ has an important role in the granulosa cells that surround the maturing oocyte. After fertilisation, PPAR-γ and PPAR-β/δ are essential regulators of placentation and the subsequent development of key metabolic tissues such as skeletal muscle and adipose cells. Activation of PPAR-γ and PPAR-β/δ during fetal development has the potential to modify the growth and development of these tissues. PPAR-α is expressed at low levels in the fetal liver, however, this expression may be important, as changes in the methylation of DNA in its promoter region are reported to take place during this period of development. This epigenetic modification then programmes subsequent expression. These findings suggest that two separate PPAR-dependent mechanisms may be involved in the fetal adaptations to the maternal diet, one, mediated by PPAR-γ and PPAR-β/δ, regulating cell growth and differentiation; and another adapting long-term lipid metabolism via epigenetic changes in PPAR-α to optimise postnatal survival.
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43
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Lin J, Chen A. Curcumin diminishes the impacts of hyperglycemia on the activation of hepatic stellate cells by suppressing membrane translocation and gene expression of glucose transporter-2. Mol Cell Endocrinol 2011; 333:160-71. [PMID: 21195127 PMCID: PMC3039105 DOI: 10.1016/j.mce.2010.12.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 11/22/2010] [Accepted: 12/20/2010] [Indexed: 01/23/2023]
Abstract
Diabetes is featured by elevated levels of blood glucose, i.e. hyperglycemia, which might be a risk factor for hepatic fibrogenesis in patients with non-alcoholic steatohepatitis. Hepatic stellate cells (HSCs) are the major effectors during hepatic fibrogenesis. This study was designed to evaluate impacts of high levels of glucose on HSC activation, assess roles of the phytochemical curcumin in attenuating the glucose impacts, and elucidate underlying mechanisms. In this report, levels of intracellular glucose were measured. Contents and gene expression of glucose transporter-2 (GLUT2) in cell fractions were examined. Levels of cellular glutathione and oxidative stress were analyzed. We observed that high levels of glucose induced cell proliferation, type I collagen production and expression of genes relevant to HSC activation, and elevated intracellular glucose levels in cultured HSCs. Curcumin eliminated the stimulatory impacts. Curcumin abrogated the membrane translocation of GLUT2 by interrupting the p38 MAPK signaling pathway. In addition, curcumin suppressed glut2 expression by stimulating the activity of peroxisome proliferator-activated receptor-gamma (PPARγ) and de novo synthesis of glutathione. In conclusion, hyperglycemia stimulated HSC activation in vitro by increasing intracellular glucose, which was eliminated by curcumin by blocking the membrane translocation of GLUT2 and suppressing glut2 expression. The latter was mediated by activating PPARγ and attenuating oxidative stress. Our results presented evidence to impacts of hyperglycemia on stimulating HSC activation and hepatic fibrogenesis, and provided novel insights into the mechanisms by which curcumin eliminated the hyperglycemia-caused HSC activation and potential therapeutic strategies for treatment of diabetes-associated hepatic fibrogenesis.
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Affiliation(s)
| | - Anping Chen
- Corresponding author: Department of Pathology, School of Medicine, Saint Louis University, 1100 S. Grand Blvd, Edward A. Doisy Research Center, St. Louis, MO, 63104, Tel: 314-977-7832; Fax: 314-977-8499,
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44
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Krishnamurthy M, Li J, Fellows GF, Rosenberg L, Goodyer CG, Wang R. Integrin {alpha}3, but not {beta}1, regulates islet cell survival and function via PI3K/Akt signaling pathways. Endocrinology 2011; 152:424-35. [PMID: 21177833 DOI: 10.1210/en.2010-0877] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
β1-integrin is a well-established regulator of β-cell activities; however, the role of its associated α-subunits is relatively unknown. Previously, we have shown that human fetal islet and INS-1 cells highly express α3β1-integrin and that collagens I and IV significantly enhance their survival and function; in addition, blocking β1 function in the fetal islet cells decreased adhesion on collagen I and increased apoptosis. The present study investigates the effect of blocking α3. Using α3 blocking antibody or small interfering RNA, the effects of α3-integrin blockade were examined in isolated human fetal or adult islet cells or INS-1 cells, cultured on collagens I or IV. In parallel, β1 blockade was analyzed in INS-1 cells. Perturbing α3 function in human islet or INS-1 cells resulted in significant decreases in cell function (adhesion, spreading, proliferation and Pdx1 and insulin expression/secretion), primarily on collagen IV. A significant decrease in focal adhesion kinase and ERK1/2 phosphorylation and increased caspase3 cleavage were observed on both collagens. These effects were similar to changes after β1 blockade. Interestingly, only α3 blockade reduced expression of phospho-Akt and members of its downstream signaling cascades (glycogen synthase kinase β and X-linked inhibitor of apoptosis), demonstrating a specific effect of α3 on the phosphatidylinositol 3-kinase/Akt pathway. These results suggest that α3- as well as β1-integrin-extracellular matrix interactions are critical for modulating β-cell survival and function through specialized signaling cascades and enhance our understanding of how to improve islet microenvironments for cell-based treatments of diabetes.
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Affiliation(s)
- Mansa Krishnamurthy
- Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, Ontario N6C 2V5, Canada
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45
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Shi J, McLamore ES, Jaroch D, Claussen JC, Mirmira RG, Rickus JL, Porterfield DM. Oscillatory glucose flux in INS 1 pancreatic β cells: a self-referencing microbiosensor study. Anal Biochem 2010; 411:185-93. [PMID: 21167120 DOI: 10.1016/j.ab.2010.12.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 12/08/2010] [Accepted: 12/10/2010] [Indexed: 12/27/2022]
Abstract
Signaling and insulin secretion in β cells have been reported to demonstrate oscillatory modes, with abnormal oscillations associated with type 2 diabetes. We investigated cellular glucose influx in β cells with a self-referencing (SR) microbiosensor based on nanomaterials with enhanced performance. Dose-response analyses with glucose and metabolic inhibition studies were used to study oscillatory patterns and transporter kinetics. For the first time, we report a stable and regular oscillatory uptake of glucose (averaged period 2.9±0.6 min), which corresponds well with an oscillator model. This oscillatory behavior is part of the feedback control pathway involving oxygen, cytosolic Ca(2+)/ATP, and insulin secretion (periodicity approximately 3 min). Glucose stimulation experiments show that the net Michaelis-Menten constant (6.1±1.5 mM) is in between GLUT2 and GLUT9. Phloretin inhibition experiments show an EC(50) value of 28±1.6 μM phloretin for class I GLUT proteins and a concentration of 40±0.6 μM phloretin caused maximum inhibition with residual nonoscillating flux, suggesting that the transporters not inhibited by phloretin are likely responsible for the remaining nonoscillatory uptake, and that impaired uptake via GLUT2 may be the cause of the oscillation loss in type 2 diabetes. Transporter studies using the SR microbiosensor will contribute to diabetes research and therapy development by exploring the nature of oscillatory transport mechanisms.
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Affiliation(s)
- Jin Shi
- Physiological Sensing Facility, 1203 W. State Street, Purdue University, West Lafayette, IN 47907-2057, USA
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46
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Gupta D, Kono T, Evans-Molina C. The role of peroxisome proliferator-activated receptor γ in pancreatic β cell function and survival: therapeutic implications for the treatment of type 2 diabetes mellitus. Diabetes Obes Metab 2010; 12:1036-47. [PMID: 20977574 PMCID: PMC3764483 DOI: 10.1111/j.1463-1326.2010.01299.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The pathogenesis of type 2 diabetes mellitus involves both peripheral insulin resistance and dysfunctional insulin secretion from the pancreatic β cell. Currently, there is intense research focus on delineating the etiologies of pancreatic β cell dysfunction in type 2 diabetes. However, there remains an unmet clinical need to establish therapeutic guidelines and strategies that emphasize the preservation of pancreatic β cell function in at-risk and affected individuals. Thiazolidinediones are orally active agents approved for use in type 2 diabetes and act as agonists of the nuclear hormone receptor PPAR-γ. These drugs improve insulin sensitivity, but there is also a growing appreciation of PPAR-γ actions within the β cell. PPAR-γ has been shown to regulate directly key β cell genes involved in glucose sensing, insulin secretion and insulin gene transcription. Further, pharmacologic PPAR-γ activation has been shown to protect against glucose-, lipid-, cytokine- and islet amyloid polypeptide (IAPP)-induced activation of numerous stress pathways. This article will review the mechanisms by which PPAR-γ activation acts to maintain β cell function and survival in type 2 diabetes mellitus and highlight some of the current controversies in this field.
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Affiliation(s)
- D Gupta
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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47
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Yang J, Chi Y, Burkhardt BR, Guan Y, Wolf BA. Leucine metabolism in regulation of insulin secretion from pancreatic beta cells. Nutr Rev 2010; 68:270-9. [PMID: 20500788 DOI: 10.1111/j.1753-4887.2010.00282.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Leucine, a branched-chain amino acid that must be supplied in the daily diet, plays an important role in controlling protein synthesis and regulating cell metabolism in various cell types. In pancreatic beta cells, leucine acutely stimulates insulin secretion by serving as both metabolic fuel and allosteric activator of glutamate dehydrogenase to enhance glutaminolysis. Leucine has also been shown to regulate gene transcription and protein synthesis in pancreatic islet beta cells via both mTOR-dependent and -independent pathways at physiological concentrations. Long-term treatment with leucine has been shown to improve insulin secretory dysfunction of human diabetic islets via upregulation of certain key metabolic genes. In vivo, leucine administration improves glycemic control in humans and rodents with type 2 diabetes. This review summarizes and discusses the recent findings regarding the effects of leucine metabolism on pancreatic beta-cell function.
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Affiliation(s)
- Jichun Yang
- Department of Physiology and Pathophysiology, Peking University Diabetes Center, Peking University Health Science Center, Beijing, China.
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48
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AMPK enhances the expression of pancreatic duodenal homeobox-1 via PPARalpha, but not PPARgamma, in rat insulinoma cell line INS-1. Acta Pharmacol Sin 2010; 31:963-9. [PMID: 20644547 DOI: 10.1038/aps.2010.78] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
AIM To investigate whether AMP-activated protein kinase (AMPK) regulates the expression of pancreatic duodenal homeobox-1 (PDX-1), a beta-cell-specific transcription factor and whether PPARalpha/gamma is involved in the regulation of pancreatic beta-cell lines after acute stimulation. METHODS Rat insulinoma cell line INS-1 was treated with an activator (AICAR) or inhibitor (Compound C) of AMPK as well as inhibitors of PPARs (MK886 to PPARalpha and BADGE to PPARgamma). The mRNA levels of PDX-1, PPARalpha and PPARgamma were measured using real-time RT-PCR, and Western blotting was used to detect the protein expression of these factors. RESULTS Activation of AMPK by AICAR induced significantly increased the expression of PDX-1, and this increase was abrogated when AMPK was inactivated by Compound C. Similarly, the expression of PPARalpha and PPARgamma was also increased by AICAR or decreased by Compound C. However AMPK activation did not increase nuclear PDX-1 protein levels when PPARalpha was inhibited. In contrast, AMPK activation still up-regulated PDX-1 protein levels during PPARgamma inhibition. Additionally, PPARalpha activation induced by fenofibrate significantly enhanced nuclear PDX-1 protein expression. CONCLUSION AMPK regulates the expression of PDX-1 at both the transcriptional and protein levels, and PPARalpha may be acutely involved in the regulation of INS-1 cells.
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49
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Chen TS, Tan SS, Yeo RWY, Teh BJ, Luo R, Li G, Lim SK. Delineating biological pathways unique to embryonic stem cell-derived insulin-producing cell lines from their noninsulin-producing progenitor cell lines. Endocrinology 2010; 151:3600-10. [PMID: 20501672 DOI: 10.1210/en.2009-1418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To identify unique biochemical pathways in embryonic stem cell-derived insulin-producing cells as potential therapeutic targets to prevent or delay beta-cell dysfunction or death in diabetic patients, comparative genome-wide gene expression studies of recently derived mouse insulin-producing cell lines and their progenitor cell lines were performed using microarray technology. Differentially expressed genes were functionally clustered to identify important biochemical pathways in these insulin-producing cell lines. Biochemical or cellular assays were then performed to assess the relevance of these pathways to the biology of these cells. A total of 185 genes were highly expressed in the insulin-producing cell lines, and computational analysis predicted the pentose phosphate pathway (PPP), clathrin-mediated endocytosis, and the peroxisome proliferator-activated receptor (PPAR) signaling pathway as important pathways in these cell lines. Insulin-producing ERoSHK cells were more resistant to hydrogen peroxide (H(2)O(2))-induced oxidative stress. Inhibition of PPP by dehydroepiandrosterone and 6-aminonicotinamide abrogated this H(2)O(2) resistance with a concomitant decrease in PPP activity as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Clathrin-mediated endocytosis, which is essential in maintaining membrane homeostasis in secreting cells, was up-regulated by glucose in ERoSHK but not in their progenitor ERoSH cells. Its inhibition by chlorpromazine at high glucose concentration was toxic to the cells. Troglitazone, a PPARG agonist, up-regulated expression of Ins1 and Ins2 but not Glut2. Gene expression analysis has identified the PPP, clathrin-mediated endocytosis, and the PPAR signaling pathway as the major delineating pathways in these insulin-producing cell lines, and their biological relevance was confirmed by biochemical and cellular assays.
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Affiliation(s)
- Tian Sheng Chen
- Institute of Medical Biology, Agency for Science, Technology, and Research, Singapore
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50
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DeFronzo RA. Insulin resistance, lipotoxicity, type 2 diabetes and atherosclerosis: the missing links. The Claude Bernard Lecture 2009. Diabetologia 2010; 53:1270-87. [PMID: 20361178 PMCID: PMC2877338 DOI: 10.1007/s00125-010-1684-1] [Citation(s) in RCA: 575] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 12/22/2009] [Indexed: 12/15/2022]
Abstract
Insulin resistance is a hallmark of type 2 diabetes mellitus and is associated with a metabolic and cardiovascular cluster of disorders (dyslipidaemia, hypertension, obesity [especially visceral], glucose intolerance, endothelial dysfunction), each of which is an independent risk factor for cardiovascular disease (CVD). Multiple prospective studies have documented an association between insulin resistance and accelerated CVD in patients with type 2 diabetes, as well as in non-diabetic individuals. The molecular causes of insulin resistance, i.e. impaired insulin signalling through the phosphoinositol-3 kinase pathway with intact signalling through the mitogen-activated protein kinase pathway, are responsible for the impairment in insulin-stimulated glucose metabolism and contribute to the accelerated rate of CVD in type 2 diabetes patients. The current epidemic of diabetes is being driven by the obesity epidemic, which represents a state of tissue fat overload. Accumulation of toxic lipid metabolites (fatty acyl CoA, diacylglycerol, ceramide) in muscle, liver, adipocytes, beta cells and arterial tissues contributes to insulin resistance, beta cell dysfunction and accelerated atherosclerosis, respectively, in type 2 diabetes. Treatment with thiazolidinediones mobilises fat out of tissues, leading to enhanced insulin sensitivity, improved beta cell function and decreased atherogenesis. Insulin resistance and lipotoxicity represent the missing links (beyond the classical cardiovascular risk factors) that help explain the accelerated rate of CVD in type 2 diabetic patients.
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Affiliation(s)
- R A DeFronzo
- Diabetes Division, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive-MSC 7886, San Antonio, TX, 78229, USA.
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