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Yadav R, Patel B. Insights on effects of Wnt pathway modulation on insulin signaling and glucose homeostasis for the treatment of type 2 diabetes mellitus: Wnt activation or Wnt inhibition? Int J Biol Macromol 2024; 261:129634. [PMID: 38272413 DOI: 10.1016/j.ijbiomac.2024.129634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/27/2023] [Accepted: 01/06/2024] [Indexed: 01/27/2024]
Abstract
Type 2 diabetes mellitus (T2DM) is a major worldwide chronic disease and can lead to serious diabetic complications. Despite the availability of many anti-diabetic agents in the market, they are unable to meet the long-term treatment goals. Also, they cause many side effects which justify the need for novel class of anti-diabetic drugs with newer mechanism of action. Wnt signaling is one of such novel target pathways which can be explored for metabolic disorders. Many key components of the Wnt signaling are involved in the regulation of glucose homeostasis. Polymorphism in the Transcription factor 7-like 2 (TCF7L2) gene, and mutations in the LRP5 (LDL Receptor Related Protein 5) gene lead to disturbed glucose metabolism and obesity. Despite of several years of research in this field, there is no concrete proof of concept available on whether Wnt activation or Wnt inhibition is the beneficial approach for the treatment of T2DM. Here, we have summarized the conclusions of relevant published research studies to give structured insights into possibilities to explore Wnt modulation as a novel target pathway for the treatment of T2DM. The review also highlights the present challenges and future opportunities towards the development of anti-diabetic small molecules targeting the Wnt signaling pathway.
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Affiliation(s)
- Ruchi Yadav
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad, Gujarat 382481, India
| | - Bhumika Patel
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad, Gujarat 382481, India.
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2
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Suthon S, Tangjittipokin W. Mechanisms and Physiological Roles of Polymorphisms in Gestational Diabetes Mellitus. Int J Mol Sci 2024; 25:2039. [PMID: 38396716 PMCID: PMC10888615 DOI: 10.3390/ijms25042039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 02/03/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Gestational diabetes mellitus (GDM) is a significant pregnancy complication linked to perinatal complications and an elevated risk of future metabolic disorders for both mothers and their children. GDM is diagnosed when women without prior diabetes develop chronic hyperglycemia due to β-cell dysfunction during gestation. Global research focuses on the association between GDM and single nucleotide polymorphisms (SNPs) and aims to enhance our understanding of GDM's pathogenesis, predict its risk, and guide patient management. This review offers a summary of various SNPs linked to a heightened risk of GDM and explores their biological mechanisms within the tissues implicated in the development of the condition.
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Affiliation(s)
- Sarocha Suthon
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
- Siriraj Center of Research Excellence for Diabetes and Obesity, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Research Excellence Management, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Watip Tangjittipokin
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
- Siriraj Center of Research Excellence for Diabetes and Obesity, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
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3
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G M, Govindarajan S, Veeraraghavan V, Varadarajan S, Balasubramaniam A, R D. Used Toothbrush as a Potential Source of Gene Expression Among Subjects With Systemic Disease and Adverse Habits. Cureus 2022; 14:e31391. [DOI: 10.7759/cureus.31391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2022] [Indexed: 11/15/2022] Open
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4
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Yang Y, Shen M, Li L, Long Y, Wang L, Lang B, Wu R. Olanzapine Promotes the Occurrence of Metabolic Disorders in Conditional TCF7L2-Knockout Mice. Front Cell Dev Biol 2022; 10:890472. [PMID: 35874808 PMCID: PMC9298277 DOI: 10.3389/fcell.2022.890472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/16/2022] [Indexed: 11/29/2022] Open
Abstract
Objectives: Schizophrenia (SCZ) patients display higher incidence of metabolic syndrome (MetS) and comorbidity of type II diabetes. Both atypical antipsychotics and genetic variants are believed to predispose the patients with the risk, but their interplay remains largely unknown. TCF7L2 is one of the most common genes strongly associated with glucose homeostasis which also participates in the pathogenesis of schizophrenia. In this study, we aimed to explore the regulatory roles of TCF7L2 in atypical antipsychotics-induced MetS. Methods: Mice with pancreatic β-cell–specific Tcf7l2 deletion (CKO) were generated. The CKO mice and control littermates were subjected to olanzapine (4 mg/kg/day) or saline gavage for 6 weeks. Metabolic indices, β cell mass, and the expressing levels of TCF7L2 and GLP-1R in the pancreatic tissue were closely monitored. Results: Tcf7l2 CKO mice displayed a spectrum of core features of MetS, which included remarkably increased rate of weight gain, higher fasting insulin, higher values of blood lipids (cholesterol, triglyceride, and low-density lipoprotein), impaired glucose tolerance, and hypertrophy of adipocytes. Notably, these effects could be further exacerbated by olanzapine. In addition, Tcf7l2 CKO mice with the olanzapine group showed significantly decreased expressions of GLP-1R protein and a trend of reduced pancreatic β-cell mass. RT-qPCR revealed that the CKO mice presented a significantly less transcription of Sp5, an important element of the Wnt signaling pathway. Conclusion: Our study illustrates that mice with pancreatic β-cell–targeted Tcf7l2 deletion were more vulnerable to suffer metabolic abnormalities after olanzapine administration. This impairment may be mediated by the reduced expression of GLP-1R.
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Affiliation(s)
- Ye Yang
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Manjun Shen
- Shenzhen Nanshan Center for Chronic Disease Control, Department of Psychiatry, Shenzhen, China
| | - Li Li
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yujun Long
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Lu Wang
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Bing Lang
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Bing Lang, ; Renrong Wu,
| | - Renrong Wu
- National Clinical Research Center for Mental Disorders, Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
- *Correspondence: Bing Lang, ; Renrong Wu,
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5
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Gu J, Shao W, Liu D, Feng JN, Pang J, Jin T. Liraglutide stimulates the β-catenin signaling cascade in mouse epididymal fat tissue. J Mol Endocrinol 2022; 69:343-356. [PMID: 35552259 DOI: 10.1530/jme-22-0026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/12/2022] [Indexed: 11/08/2022]
Abstract
Although canonical Wnt signaling pathway activation was shown to negatively regulate adipogenesis, recent investigations suggest that Wnt pathway effectors TCF7L2 and β-catenin (β-cat) in adipose tissues are also involved in energy homeostasis during adulthood. In assessing the metabolic beneficial effect of GLP-1-based diabetes drugs in high-fat diet (HFD)-challenged mice, we observed that liraglutide treatment affected the expression of a battery of adipose tissue-specific genes, including those that encode adiponectin and leptin, mainly in epididymal white adipose tissue (eWAT). Fourteen-week HFD challenge repressed TCF7L2 and β-cat S675 phosphorylation in eWAT, while such repression was reversed by liraglutide treatment (150 µg/kg body weight daily) during weeks 10-14. In Glp1r-/-mice, liraglutide failed in stimulating TCF7L2 or β-cat in eWAT. We detected Glp1r expression in mouse eWAT and its level is enriched in its stromal vascular fraction (SVF). Mouse eWAT-SVF showed reduced expression of Tcf7l2 and its Tcf7l2 level could not be stimulated by liraglutide treatment; while following adipogenic differentiation, rat eWAT-SVF showed elevated Tcf7l2 expression. Direct in vitro liraglutide treatment in eWAT-SVF stimulated CREB S133, β-cat S675 phosphorylation, and cellular cAMP level. Thus, cAMP/β-cat signaling cascade can be stimulated by liraglutide in eWAT via GLP-1R expressed in eWAT-SVF.
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Affiliation(s)
- Jianqiu Gu
- Department of Endocrinology and Metabolism and the Institute of Endocrinology, The First Hospital of China Medical University, Shenyang, People's Republic of China
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
| | - Weijuan Shao
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
| | - Dinghui Liu
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jia Nuo Feng
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Juan Pang
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Tianru Jin
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Centre, Temerty Faculty of Medicine, University of Toronto, Toronto, Canada
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Bhat N, Esteghamat F, Chaube BK, Gunawardhana K, Mani M, Thames C, Jain D, Ginsberg HN, Fernandes-Hernando C, Mani A. TCF7L2 transcriptionally regulates Fgf15 to maintain bile acid and lipid homeostasis through gut-liver crosstalk. FASEB J 2022; 36:e22185. [PMID: 35133032 PMCID: PMC9624374 DOI: 10.1096/fj.202101607r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/10/2022] [Accepted: 01/18/2022] [Indexed: 12/13/2022]
Abstract
FGF19/FGF15 is an endocrine regulator of hepatic bile salt and lipid metabolism, which has shown promising effects in the treatment of NASH in clinical trials. FGF19/15 is transcribed and released from enterocytes of the small intestine into enterohepatic circulation in response to bile-induced FXR activation. Previously, the TSS of FGF19 was identified to bind Wnt-regulated TCF7L2/encoded transcription factor TCF4 in colorectal cancer cells. Impaired Wnt signaling and specifical loss of function of its coreceptor LRP6 have been associated with NASH. We, therefore, examined if TCF7L2/TCF4 upregulates Fgf19 in the small intestine and restrains NASH through gut-liver crosstalk. We examined the mice globally overexpressing, haploinsufficient, and conditional knockout models of TCF7L2 in the intestinal epithelium. The TCF7L2+/- mice exhibited increased plasma bile salts and lipids and developed diet-induced fatty liver disease while mice globally overexpressing TCF7L2 were protected against these traits. Comprehensive in vivo analysis revealed that TCF7L2 transcriptionally upregulates FGF15 in the gut, leading to reduced bile synthesis and diminished intestinal lipid uptake. Accordingly, VilinCreert2 ; Tcf7L2fl/fl mice showed reduced Fgf19 in the ileum, and increased plasma bile. The global overexpression of TCF7L2 in mice with metabolic syndrome-linked LRP6R611C substitution rescued the fatty liver and fibrosis in the latter. Strikingly, the hepatic levels of TCF4 were reduced and CYP7a1 was increased in human NASH, indicating the relevance of TCF4-dependent regulation of bile synthesis to human disease. These studies identify the critical role of TCF4 as an upstream regulator of the FGF15-mediated gut-liver crosstalk that maintains bile and liver triglyceride homeostasis.
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Affiliation(s)
- Neha Bhat
- Department of Internal Medicine, Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Fatemehsadat Esteghamat
- Department of Internal Medicine, Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Bal Krishna Chaube
- Department of Comparative Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Kushan Gunawardhana
- Department of Internal Medicine, Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Mitra Mani
- New York Medical College, Valhalla, New York, USA,Department of Internal Medicine, Columbia University College of Physicians and Surgeon, New York, New York, USA
| | - Clay Thames
- Department of Internal Medicine, Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dhanpat Jain
- Department of Pathology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Henry N. Ginsberg
- Department of Internal Medicine, Columbia University College of Physicians and Surgeon, New York, New York, USA
| | | | - Arya Mani
- Department of Internal Medicine, Cardiovascular Research Center, Yale University School of Medicine, New Haven, Connecticut, USA,Department of Genetics, Yale School of Medicine, New Haven, Connecticut, USA
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Badakhshi Y, Shao W, Liu D, Tian L, Pang J, Gu J, Hu J, Jin T. Estrogen-Wnt signaling cascade regulates expression of hepatic fibroblast growth factor 21. Am J Physiol Endocrinol Metab 2021; 321:E292-E304. [PMID: 34229476 DOI: 10.1152/ajpendo.00638.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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
We have generated the transgenic mouse line LTCFDN in which dominant negative TCF7L2 (TCF7L2DN) is specifically expressed in the liver during adulthood. Male but not female LTCFDN mice showed elevated hepatic and plasma triglyceride (TG) levels, indicating the existence of estrogen-β-cat/TCF signaling cascade that regulates hepatic lipid homeostasis. We show here that hepatic fibroblast growth factor 21 (FGF21) expression was reduced in male but not in female LTCFDN mice. The reduction was not associated with altered hepatic expression of peroxisome proliferator-activated receptor α (PPARα). In mouse primary hepatocytes (MPH), Wnt-3a treatment increased FGF21 expression in the presence of PPARα inhibitor. Results from our luciferase-reporter assay and chromatin immunoprecipitation suggest that evolutionarily conserved TCF binding motifs (TCFBs) on Fgf21 promoter mediate Wnt-3a-induced Fgf21 transactivation. Female mice showed reduced hepatic FGF21 production and circulating FGF21 level following ovariectomy (OVX), associated with reduced hepatic TCF expression and β-catenin S675 phosphorylation. Finally, in MPH, estradiol (E2) treatment enhanced FGF21 expression, as well as binding of TCF7L2 and ribonucleic acid (RNA) polymerase II to the Fgf21 promoter; and the enhancement can be attenuated by the G-protein-coupled estrogen receptor 1 (GPER) antagonist G15. Our observations hence indicate that hepatic FGF21 is among the effectors of the newly recognized E2-β-cat/TCF signaling cascade.NEW & NOTEWORTHY FGF21 is mainly produced in the liver. Therapeutic effect of FGF21 analogues has been demonstrated in clinical trials on reducing hyperlipidemia. We show here that Fgf21 transcription is positively regulated by Wnt pathway effector β-cat/TCF. Importantly, hepatic β-cat/TCF activity can be regulated by the female hormone estradiol, involving GPER. The investigation enriched our understanding on hepatic FGF21 hormone production, and expanded our view on metabolic functions of the Wnt pathway in the liver.
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Affiliation(s)
- Yasaman Badakhshi
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
- Divison of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Banting and Best Diabetes Centre, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Weijuan Shao
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
- Divison of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Banting and Best Diabetes Centre, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Dinghui Liu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Lili Tian
- Divison of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Banting and Best Diabetes Centre, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Juan Pang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Jianqiu Gu
- Divison of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Departmemt of Endocrinology and Metabolism and the Institute of Endocrinology, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Jim Hu
- Hospital for Sick Children, Toronto, Ontario, Canada
| | - Tianru Jin
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Canada
- Divison of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Banting and Best Diabetes Centre, Faculty of Medicine, University of Toronto, Toronto, Canada
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8
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Zhang Z, Xu L, Xu X. The role of transcription factor 7-like 2 in metabolic disorders. Obes Rev 2021; 22:e13166. [PMID: 33615650 DOI: 10.1111/obr.13166] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/08/2020] [Accepted: 10/08/2020] [Indexed: 12/13/2022]
Abstract
Transcription factor 7-like 2 (TCF7L2), a member of the T cell factor/lymphoid enhancer factor family, generally forms a complex with β-catenin to regulate the downstream target genes as an effector of the canonical Wnt signalling pathway. TCF7L2 plays a vital role in various biological processes and functions in many organs and tissues, including the liver, islet and adipose tissues. Further, TCF7L2 down-regulates hepatic gluconeogenesis and promotes lipid accumulation. In islets, TCF7L2 not only affects the insulin secretion of the β-cells but also has an impact on other cells. In addition, TCF7L2 influences adipogenesis in adipose tissues. Thus, an out-of-control TCF7L2 expression can result in metabolic disorders. The TCF7L2 gene is composed of 17 exons, generating 13 different transcripts, and has many single-nucleotide polymorphisms (SNPs). The discovery that these SNPs have an impact on the risk of type 2 diabetes (T2D) has attracted thorough investigations in the study of TCF7L2. Apart from T2D, TCF7L2 SNPs are also associated with type 1, posttransplant and other types of diabetes. Furthermore, TCF7L2 variants affect the progression of other disorders, such as obesity, cancers, metabolic syndrome and heart diseases. Finally, the interaction between TCF7L2 variants and diet also needs to be investigated.
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Affiliation(s)
- Zhensheng Zhang
- Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China.,Zhejiang University School of Medicine, Hangzhou, China
| | - Li Xu
- Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China.,NHC Key Laboratory of Combined Multi-organ Transplantation, Hangzhou, China.,Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Xu
- Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Cancer Center, Hangzhou, China
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Ghiasi SM, Rutter GA. Consequences for Pancreatic β-Cell Identity and Function of Unregulated Transcript Processing. Front Endocrinol (Lausanne) 2021; 12:625235. [PMID: 33763030 PMCID: PMC7984428 DOI: 10.3389/fendo.2021.625235] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/26/2021] [Indexed: 12/25/2022] Open
Abstract
Mounting evidence suggests a role for alternative splicing (AS) of transcripts in the normal physiology and pathophysiology of the pancreatic β-cell. In the apparent absence of RNA repair systems, RNA decay pathways are likely to play an important role in controlling the stability, distribution and diversity of transcript isoforms in these cells. Around 35% of alternatively spliced transcripts in human cells contain premature termination codons (PTCs) and are targeted for degradation via nonsense-mediated decay (NMD), a vital quality control process. Inflammatory cytokines, whose levels are increased in both type 1 (T1D) and type 2 (T2D) diabetes, stimulate alternative splicing events and the expression of NMD components, and may or may not be associated with the activation of the NMD pathway. It is, however, now possible to infer that NMD plays a crucial role in regulating transcript processing in normal and stress conditions in pancreatic β-cells. In this review, we describe the possible role of Regulated Unproductive Splicing and Translation (RUST), a molecular mechanism embracing NMD activity in relationship to AS and translation of damaged transcript isoforms in these cells. This process substantially reduces the abundance of non-functional transcript isoforms, and its dysregulation may be involved in pancreatic β-cell failure in diabetes.
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Affiliation(s)
- Seyed M. Ghiasi
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
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Nguyen-Tu MS, Martinez-Sanchez A, Leclerc I, Rutter GA, da Silva Xavier G. Adipocyte-specific deletion of Tcf7l2 induces dysregulated lipid metabolism and impairs glucose tolerance in mice. Diabetologia 2021; 64:129-141. [PMID: 33068125 PMCID: PMC7567653 DOI: 10.1007/s00125-020-05292-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/07/2020] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Transcription factor 7-like 2 (TCF7L2) is a downstream effector of the Wnt/β-catenin signalling pathway implicated in type 2 diabetes risk through genome-wide association studies. Although its expression is critical for adipocyte development, the potential roles of changes in adipose tissue TCF7L2 levels in diabetes risk are poorly defined. Here, we investigated whether forced changes in Tcf7l2 expression in adipocytes affect whole body glucose or lipid metabolism and crosstalk between disease-relevant tissues. METHODS Tcf7l2 was selectively ablated in mature adipocytes in C57BL/6J mice using Cre recombinase under Adipoq promoter control to recombine Tcf7l2 alleles floxed at exon 1 (referred to as aTCF7L2 mice). aTCF7L2 mice were fed normal chow or a high-fat diet for 12 weeks. Glucose and insulin sensitivity, as well as beta cell function, were assessed in vivo and in vitro. Levels of circulating NEFA, selected hormones and adipokines were measured using standard assays. RESULTS Reduced TCF7L2 expression in adipocytes altered glucose tolerance and insulin secretion in male but not in female mice. Thus, on a normal chow diet, male heterozygote knockout mice (aTCF7L2het) exhibited impaired glucose tolerance at 16 weeks (p = 0.03) and increased fat mass (1.4 ± 0.1-fold, p = 0.007) but no changes in insulin secretion. In contrast, male homozygote knockout (aTCF7L2hom) mice displayed normal body weight but impaired oral glucose tolerance at 16 weeks (p = 0.0001). These changes were mechanistically associated with impaired in vitro glucose-stimulated insulin secretion (decreased 0.5 ± 0.1-fold vs control mice, p = 0.02) and decreased levels of the incretins glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide (0.6 ± 0.1-fold and 0.4 ± 0.1-fold vs control mice, p = 0.04 and p < 0.0001, respectively). Circulating levels of plasma NEFA and fatty acid binding protein 4 were increased by 1.3 ± 0.1-fold and 1.8 ± 0.3-fold vs control mice (p = 0.03 and p = 0.05, respectively). Following exposure to a high-fat diet for 12 weeks, male aTCF7L2hom mice exhibited reduced in vivo glucose-stimulated insulin secretion (0.5 ± 0.1-fold vs control mice, p = 0.02). CONCLUSIONS/INTERPRETATION Loss of Tcf7l2 gene expression selectively in adipocytes leads to a sexually dimorphic phenotype, with impairments not only in adipocytes, but also in pancreatic islet and enteroendocrine cells in male mice only. Our findings suggest novel roles for adipokines and incretins in the effects of diabetes-associated variants in TCF7L2, and further illuminate the roles of TCF7L2 in glucose homeostasis and diabetes risk. Graphical abstract.
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Affiliation(s)
- Marie-Sophie Nguyen-Tu
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Hammersmith Hospital, Imperial College Centre for Translational and Experimental Medicine, London, UK
| | - Aida Martinez-Sanchez
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Hammersmith Hospital, Imperial College Centre for Translational and Experimental Medicine, London, UK
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Hammersmith Hospital, Imperial College Centre for Translational and Experimental Medicine, London, UK
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Hammersmith Hospital, Imperial College Centre for Translational and Experimental Medicine, London, UK.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
| | - Gabriela da Silva Xavier
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Hammersmith Hospital, Imperial College Centre for Translational and Experimental Medicine, London, UK.
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, UK.
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11
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Torres JM, Abdalla M, Payne A, Fernandez-Tajes J, Thurner M, Nylander V, Gloyn AL, Mahajan A, McCarthy MI. A Multi-omic Integrative Scheme Characterizes Tissues of Action at Loci Associated with Type 2 Diabetes. Am J Hum Genet 2020; 107:1011-1028. [PMID: 33186544 PMCID: PMC7820628 DOI: 10.1016/j.ajhg.2020.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/20/2020] [Indexed: 12/30/2022] Open
Abstract
Resolving the molecular processes that mediate genetic risk remains a challenge because most disease-associated variants are non-coding and functional characterization of these signals requires knowledge of the specific tissues and cell-types in which they operate. To address this challenge, we developed a framework for integrating tissue-specific gene expression and epigenomic maps to obtain "tissue-of-action" (TOA) scores for each association signal by systematically partitioning posterior probabilities from Bayesian fine-mapping. We applied this scheme to credible set variants for 380 association signals from a recent GWAS meta-analysis of type 2 diabetes (T2D) in Europeans. The resulting tissue profiles underscored a predominant role for pancreatic islets and, to a lesser extent, adipose and liver, particularly among signals with greater fine-mapping resolution. We incorporated resulting TOA scores into a rule-based classifier and validated the tissue assignments through comparison with data from cis-eQTL enrichment, functional fine-mapping, RNA co-expression, and patterns of physiological association. In addition to implicating signals with a single TOA, we found evidence for signals with shared effects in multiple tissues as well as distinct tissue profiles between independent signals within heterogeneous loci. Lastly, we demonstrated that TOA scores can be directly coupled with eQTL colocalization to further resolve effector transcripts at T2D signals. This framework guides mechanistic inference by directing functional validation studies to the most relevant tissues and can gain power as fine-mapping resolution and cell-specific annotations become richer. This method is generalizable to all complex traits with relevant annotation data and is made available as an R package.
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Affiliation(s)
- Jason M. Torres
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Moustafa Abdalla
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Anthony Payne
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Juan Fernandez-Tajes
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Matthias Thurner
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK,Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK
| | - Vibe Nylander
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK
| | - Anna L. Gloyn
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK,Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK,Division of Endocrinology, Department of Pediatrics, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Anubha Mahajan
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK,Corresponding author
| | - Mark I. McCarthy
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7BN, UK,Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK,Corresponding author
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12
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Hu M, Cherkaoui I, Misra S, Rutter GA. Functional Genomics in Pancreatic β Cells: Recent Advances in Gene Deletion and Genome Editing Technologies for Diabetes Research. Front Endocrinol (Lausanne) 2020; 11:576632. [PMID: 33162936 PMCID: PMC7580382 DOI: 10.3389/fendo.2020.576632] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/17/2020] [Indexed: 12/13/2022] Open
Abstract
The inheritance of variants that lead to coding changes in, or the mis-expression of, genes critical to pancreatic beta cell function can lead to alterations in insulin secretion and increase the risk of both type 1 and type 2 diabetes. Recently developed clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) gene editing tools provide a powerful means of understanding the impact of identified variants on cell function, growth, and survival and might ultimately provide a means, most likely after the transplantation of genetically "corrected" cells, of treating the disease. Here, we review some of the disease-associated genes and variants whose roles have been probed up to now. Next, we survey recent exciting developments in CRISPR/Cas9 technology and their possible exploitation for β cell functional genomics. Finally, we will provide a perspective as to how CRISPR/Cas9 technology may find clinical application in patients with diabetes.
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Affiliation(s)
- Ming Hu
- Section of Cell Biology and Functional Genomics, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Ines Cherkaoui
- Section of Cell Biology and Functional Genomics, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Shivani Misra
- Metabolic Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Faculty of Medicine, Imperial College London, London, United Kingdom
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13
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Hayami T, Yokoi N, Yamaguchi T, Honda K, Murao N, Takahashi H, Wang S, Seino Y, Kamiya H, Yabe D, Sweet IR, Mizoguchi A, Nakamura J, Seino S. Tumor-like features of gene expression and metabolic profiles in enlarged pancreatic islets are associated with impaired incretin-induced insulin secretion in obese diabetes: A study of Zucker fatty diabetes mellitus rat. J Diabetes Investig 2020; 11:1434-1447. [PMID: 32279428 PMCID: PMC7610108 DOI: 10.1111/jdi.13272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/26/2020] [Accepted: 04/05/2020] [Indexed: 12/13/2022] Open
Abstract
AIMS/INTRODUCTION Pancreatic islets are heterogenous. To clarify the relationship between islet heterogeneity and incretin action in the islets, we studied gene expression and metabolic profiles of non-large and enlarged islets of the Zucker fatty diabetes mellitus rat, an obese diabetes model, as well as incretin-induced insulin secretion (IIIS) in these islets. MATERIALS AND METHODS Pancreatic islets of control (fa/+) and fatty (fa/fa) rats at 8 and 12 weeks-of-age were isolated. The islets of fa/fa rats at 12 weeks-of-age were separated into non-large islets (≤200 μm in diameter) and enlarged islets (>300 μm in diameter). Morphological analyses, insulin secretion experiments, transcriptome analysis, metabolome analysis and oxygen consumption analysis were carried out on these islets. RESULTS The number of enlarged islets was increased with age in fatty rats, and IIIS was significantly reduced in the enlarged islets. Markers for β-cell differentiation were markedly decreased in the enlarged islets, but those for cell proliferation were increased. Glycolysis was enhanced in the enlarged islets, whereas the tricarboxylic acid cycle was suppressed. The oxygen consumption rate under glucose stimulation was reduced in the enlarged islets. Production of glutamate, a key signal for IIIS, was decreased in the enlarged islets. CONCLUSIONS The enlarged islets of Zucker fatty diabetes mellitus rats, which are defective for IIIS, show tumor cell-like metabolic features, including a dedifferentiated state, accelerated aerobic glycolysis and impaired mitochondrial function. The age-dependent increase in such islets could contribute to the pathophysiology of obese diabetes.
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Affiliation(s)
- Tomohide Hayami
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan.,Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
| | - Norihide Yokoi
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan
| | - Takuro Yamaguchi
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan
| | - Kohei Honda
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Naoya Murao
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan
| | - Shujie Wang
- Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Japan
| | - Yusuke Seino
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Fujita Health University, Toyoake, Japan
| | - Hideki Kamiya
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
| | - Daisuke Yabe
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan
| | - Ian R Sweet
- Department of Medicine, Division of Metabolism, Endocrinology and Nutrition, University of Washington, Seattle, Washington, USA
| | - Akira Mizoguchi
- Department of Neural Regeneration and Cell Communication, Mie University Graduate School of Medicine, Tsu, Japan
| | - Jiro Nakamura
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe, Japan.,Kansai Electric Power Medical Research Institute, Kobe, Japan
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14
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Davis SPX, Kumar S, Alexandrov Y, Bhargava A, da Silva Xavier G, Rutter GA, Frankel P, Sahai E, Flaxman S, French PMW, McGinty J. Convolutional neural networks for reconstruction of undersampled optical projection tomography data applied to in vivo imaging of zebrafish. JOURNAL OF BIOPHOTONICS 2019; 12:e201900128. [PMID: 31386281 PMCID: PMC7065643 DOI: 10.1002/jbio.201900128] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 06/27/2019] [Accepted: 08/04/2019] [Indexed: 06/10/2023]
Abstract
Optical projection tomography (OPT) is a 3D mesoscopic imaging modality that can utilize absorption or fluorescence contrast. 3D images can be rapidly reconstructed from tomographic data sets sampled with sufficient numbers of projection angles using the Radon transform, as is typically implemented with optically cleared samples of the mm-to-cm scale. For in vivo imaging, considerations of phototoxicity and the need to maintain animals under anesthesia typically preclude the acquisition of OPT data at a sufficient number of angles to avoid artifacts in the reconstructed images. For sparse samples, this can be addressed with iterative algorithms to reconstruct 3D images from undersampled OPT data, but the data processing times present a significant challenge for studies imaging multiple animals. We show here that convolutional neural networks (CNN) can be used in place of iterative algorithms to remove artifacts-reducing processing time for an undersampled in vivo zebrafish dataset from 77 to 15 minutes. We also show that using CNN produces reconstructions of equivalent quality to compressed sensing with 40% fewer projections. We further show that diverse training data classes, for example, ex vivo mouse tissue data, can be used for CNN-based reconstructions of OPT data of other species including live zebrafish.
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Affiliation(s)
| | - Sunil Kumar
- Department of PhysicsImperial College LondonLondonUK
- The Francis Crick InstituteLondonUK
| | - Yuriy Alexandrov
- Department of PhysicsImperial College LondonLondonUK
- The Francis Crick InstituteLondonUK
| | | | - Gabriela da Silva Xavier
- Department of MedicineImperial College LondonLondonUK
- Institute of Metabolism and Systems ResearchUniversity of BirminghamBirminghamUK
| | - Guy A. Rutter
- Department of MedicineImperial College LondonLondonUK
| | - Paul Frankel
- Division of MedicineUniversity College LondonLondonUK
| | | | - Seth Flaxman
- Department of Mathematics and Data Science InstituteImperial College LondonLondonUK
| | - Paul M. W. French
- Department of PhysicsImperial College LondonLondonUK
- The Francis Crick InstituteLondonUK
| | - James McGinty
- Department of PhysicsImperial College LondonLondonUK
- The Francis Crick InstituteLondonUK
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15
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Tian L, Shao W, Ip W, Song Z, Badakhshi Y, Jin T. The developmental Wnt signaling pathway effector β-catenin/TCF mediates hepatic functions of the sex hormone estradiol in regulating lipid metabolism. PLoS Biol 2019; 17:e3000444. [PMID: 31589598 PMCID: PMC6797220 DOI: 10.1371/journal.pbio.3000444] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 10/17/2019] [Accepted: 09/10/2019] [Indexed: 12/11/2022] Open
Abstract
The bipartite transcription factor β-catenin (β-cat)/T cell factor (TCF), formed by free β-cat and a given TCF family member, serves as the effector of the developmental Wnt signaling cascade. β-cat/TCFs also serve as effectors of certain peptide hormones or growth factors during adulthood. We reported that liver-specific expression of dominant-negative Transcription factor 7 like 2 (TCF7L2DN) led to impaired glucose disposal. Here we show that, in this LTCFDN transgenic mouse model, serum and hepatic lipid contents were elevated in male but not in female mice. In hepatocytes, TCF7L2DN adenovirus infection led to stimulated expression of genes that encode lipogenic transcription factors and lipogenic enzymes, while estradiol (E2) treatment attenuated the stimulation, associated with Wnt-target gene activation. Mechanistically, this E2-mediated activation can be attributed to elevated β-cat Ser675 phosphorylation and TCF expression. In wild-type female mice, ovariectomy (OVX) plus high-fat diet (HFD) challenge impaired glucose disposal and insulin tolerance, associated with increased hepatic lipogenic transcription factor sterol regulatory element-binding protein 1-c (SREBP-1c) expression. In wild-type mice with OVX, E2 reconstitution attenuated HFD-induced metabolic defects. Some of the attenuation effects, including insulin intolerance, elevated liver-weight gain, and hepatic SREBP-1c expression, were not affected by E2 reconstitution in HFD-fed LTCFDN mice with OVX. Finally, the effects of E2 in hepatocytes on β-cat/TCF activation can be attenuated by the G-protein-coupled estrogen receptor (GPER) antagonist G15. Our study thus expanded the scope of functions of the Wnt pathway effector β-cat/TCF, as it can also mediate hepatic functions of E2 during adulthood. This study also enriches our mechanistic understanding of gender differences in the risk and pathophysiology of metabolic diseases.
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Affiliation(s)
- Lili Tian
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Center, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Weijuan Shao
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Center, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Wilfred Ip
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
| | - Zhuolun Song
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Center, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Yasaman Badakhshi
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Center, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Tianru Jin
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Center, Faculty of Medicine, University of Toronto, Toronto, Canada
- * E-mail:
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16
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Serotonin is elevated in risk-genotype carriers of TCF7L2 - rs7903146. Sci Rep 2019; 9:12863. [PMID: 31492908 PMCID: PMC6731216 DOI: 10.1038/s41598-019-49347-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 08/12/2019] [Indexed: 01/21/2023] Open
Abstract
The transcription factor 7-like 2 (TCF7L2) polymorphism rs7903146 is known to be tightly associated with an elevated risk for type 2 diabetes, whereas the molecular mechanisms remain elusive. We evaluated the metabolic profile of a total of 394 patients' serum samples with respect to their rs7903146 genotype using targeted metabolomics in a discovery (n = 154) and a validation (n = 240) study. We have identified serotonin as the top metabolite being increased in carriers of the risk allele. Serotonin was significantly associated with the rs7903146 genotype after full adjustment including type 2 diabetes and further top ranked metabolites. Given the role of peripheral serotonin in metabolic homeostasis and type 2 diabetes, this finding provides a first hint that the well-known impact of the TCF7L2 polymorphism on type 2 diabetes risk may involve a serotonin-dependent pathway.
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17
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Chen L, Li G, Tang L, Zhang M, Liu L, Liu A, McGinty J, Ruan S. Hyperspectral scanning laser optical tomography. JOURNAL OF BIOPHOTONICS 2019; 12:e201800221. [PMID: 30187691 DOI: 10.1002/jbio.201800221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
In order to study physical relationships within tissue volumes or even organism-level systems, the spatial distribution of multiple fluorescent markers needs to be resolved efficiently in three dimensions. Here, rather than acquiring discrete spectral images sequentially using multiple emission filters, a hyperspectral scanning laser optical tomography system is developed to obtain hyperspectral volumetric data sets with 2-nm spectral resolution of optically transparent mesoscopic (millimeter-centimeter) specimens. This is achieved by acquiring a series of point-scanning hyperspectral extended depth of field images at different angles and subsequently tomographically reconstructing the 3D intensity distribution for each wavelength. This technique is demonstrated to provide robust measurements via the comparison of spectral and intensity profiles of fluorescent bead phantoms. Due to its enhanced spectral resolving ability, this technique is also demonstrated to resolve largely overlapping fluorophores, as demonstrated by the 3D fluorescence hyperspectral reconstruction of a dual-labeled mouse thymus gland sample and the ability to distinguish tumorous and normal tissues of an unlabeled mouse intestine sample.
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Affiliation(s)
- Lingling Chen
- College of Health Science and Environmental Engineering, Shenzhen Technology University, Shenzhen, China
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
| | - Guiye Li
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
| | - Li Tang
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
- Department of Medicine, Shenzhen University, Shenzhen, China
| | - Meng Zhang
- School of Electronics and information Engineering, Beihang University, Beijing, China
| | - Lina Liu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - Ang Liu
- College of Optoelectronics Engineering, Shenzhen University, Shenzhen, China
| | - James McGinty
- Photonics Group, Department of Physics, Imperial College London, London, UK
| | - Shuangchen Ruan
- Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen, China
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18
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Mechanisms underlying the metabolic beneficial effect of curcumin intervention: Beyond anti-inflammation and anti-oxidative stress. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.obmed.2018.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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19
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Moorer MC, Riddle RC. Regulation of Osteoblast Metabolism by Wnt Signaling. Endocrinol Metab (Seoul) 2018; 33:318-330. [PMID: 30112869 PMCID: PMC6145954 DOI: 10.3803/enm.2018.33.3.318] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 07/01/2018] [Accepted: 07/08/2018] [Indexed: 12/13/2022] Open
Abstract
Wnt/β-catenin signaling plays a critical role in the achievement of peak bone mass, affecting the commitment of mesenchymal progenitors to the osteoblast lineage and the anabolic capacity of osteoblasts depositing bone matrix. Recent studies suggest that this evolutionarily-conserved, developmental pathway exerts its anabolic effects in part by coordinating osteoblast activity with intermediary metabolism. These findings are compatible with the cloning of the gene encoding the low-density lipoprotein related receptor-5 (LRP5) Wnt co-receptor from a diabetes-susceptibility locus and the now well-established linkage between Wnt signaling and metabolism. In this article, we provide an overview of the role of Wnt signaling in whole-body metabolism and review the literature regarding the impact of Wnt signaling on the osteoblast's utilization of three different energy sources: fatty acids, glucose, and glutamine. Special attention is devoted to the net effect of nutrient utilization and the mode of regulation by Wnt signaling. Mechanistic studies indicate that the utilization of each substrate is governed by a unique mechanism of control with β-catenin-dependent signaling regulating fatty acid β-oxidation, while glucose and glutamine utilization are β-catenin-independent and downstream of mammalian target of rapamycin complex 2 (mTORC2) and mammalian target of rapamycin complex 1 (mTORC1) activation, respectively. The emergence of these data has provided a new context for the mechanisms by which Wnt signaling influences bone development.
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Affiliation(s)
- Megan C Moorer
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Baltimore Veterans Administration Medical Center, Baltimore, MD, USA
| | - Ryan C Riddle
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Baltimore Veterans Administration Medical Center, Baltimore, MD, USA.
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20
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Adams JD, Vella A. What Can Diabetes-Associated Genetic Variation in TCF7L2 Teach Us About the Pathogenesis of Type 2 Diabetes? Metab Syndr Relat Disord 2018; 16:383-389. [PMID: 29993315 DOI: 10.1089/met.2018.0024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is a polygenic metabolic disorder characterized by hyperglycemia occurring as a result of impaired insulin secretion and/or insulin resistance. Among the various genetic factors associated with T2DM, a common genetic variant within the transcription factor 7-like 2 locus (TCF7L2) confers the greatest genetic risk for development of the disease. However, the mechanism(s) by which TCF7L2 predisposes to diabetes remain uncertain. Here we review the current literature pertaining to the potential mechanisms by which TCF7L2 confers risk of T2DM, using genetic variation as a probe to understand the pathogenesis of the disease.
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Affiliation(s)
- J D Adams
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Adrian Vella
- Endocrine Research Unit, Department of Endocrinology, Diabetes and Nutrition, Mayo Clinic College of Medicine , Rochester, Minnesota
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21
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Nguyen-Tu MS, da Silva Xavier G, Leclerc I, Rutter GA. Transcription factor-7-like 2 ( TCF7L2) gene acts downstream of the Lkb1/ Stk11 kinase to control mTOR signaling, β cell growth, and insulin secretion. J Biol Chem 2018; 293:14178-14189. [PMID: 29967064 PMCID: PMC6130960 DOI: 10.1074/jbc.ra118.003613] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/15/2018] [Indexed: 12/25/2022] Open
Abstract
Variants in the transcription factor-7–like 2 (TCF7L2/TCF4) gene, involved in Wnt signaling, are associated with type 2 diabetes. Loss of Tcf7l2 selectively from the β cell in mice has previously been shown to cause glucose intolerance and to lower β cell mass. Deletion of the tumor suppressor liver kinase B1 (LKB1/STK11) leads to β cell hyperplasia and enhanced glucose-stimulated insulin secretion, providing a convenient genetic model for increased β cell growth and function. The aim of this study was to explore the possibility that Tcf7l2 may be required for the effects of Lkb1 deletion on insulin secretion in the mouse β cell. Mice bearing floxed Lkb1 and/or Tcf7l2 alleles were bred with knockin mice bearing Cre recombinase inserted at the Ins1 locus (Ins1Cre), allowing highly β cell–selective deletion of either or both genes. Oral glucose tolerance was unchanged by the further deletion of a single Tcf7l2 allele in these cells. By contrast, mice lacking both Tcf7l2 alleles on this background showed improved oral glucose tolerance and insulin secretion in vivo and in vitro compared with mice lacking a single Tcf7l2 allele. Biallelic Tcf7l2 deletion also enhanced β cell proliferation, increased β cell mass, and caused changes in polarity as revealed by the “rosette-like” arrangement of β cells. Tcf7l2 deletion also increased signaling by mammalian target of rapamycin (mTOR), augmenting phospho-ribosomal S6 levels. We identified a novel signaling mechanism through which a modifier gene, Tcf7l2, lies on a pathway through which LKB1 acts in the β cell to restrict insulin secretion.
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Affiliation(s)
- Marie-Sophie Nguyen-Tu
- From the Section of Cell Biology and Functional Genomics and Pancreatic Islet and Diabetes Consortium, Division of Diabetes, Endocrinology and Metabolism, Imperial Centre for Translational and Experimental Medicine, Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Gabriela da Silva Xavier
- From the Section of Cell Biology and Functional Genomics and Pancreatic Islet and Diabetes Consortium, Division of Diabetes, Endocrinology and Metabolism, Imperial Centre for Translational and Experimental Medicine, Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Isabelle Leclerc
- From the Section of Cell Biology and Functional Genomics and Pancreatic Islet and Diabetes Consortium, Division of Diabetes, Endocrinology and Metabolism, Imperial Centre for Translational and Experimental Medicine, Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
| | - Guy A Rutter
- From the Section of Cell Biology and Functional Genomics and Pancreatic Islet and Diabetes Consortium, Division of Diabetes, Endocrinology and Metabolism, Imperial Centre for Translational and Experimental Medicine, Department of Medicine, Imperial College London, London W12 0NN, United Kingdom
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22
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Shao W, Szeto V, Song Z, Tian L, Feng ZP, Nostro MC, Jin T. The LIM homeodomain protein ISL1 mediates the function of TCF7L2 in pancreatic beta cells. J Mol Endocrinol 2018; 61:1-12. [PMID: 29678908 DOI: 10.1530/jme-17-0181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 03/29/2018] [Indexed: 11/08/2022]
Abstract
Pancreatic β-cell Tcf7l2 deletion or its functional knockdown suggested the essential role of this Wnt pathway effector in controlling insulin secretion, glucose homeostasis and β-cell gene expression. As the LIM homeodomain protein ISL1 is a suggested Wnt pathway downstream target, we hypothesize that it mediates metabolic functions of TCF7L2. We aimed to determine the role of ISL1 in mediating the function of TCF7L2 and the incretin hormone GLP-1 in pancreatic β-cells. The effect of dominant negative TCF7L2 (TCF7L2DN) mediated Wnt pathway functional knockdown on Isl1 expression was determined in βTCFDN mouse islets and in the rat insulinoma cell line INS-1 832/13. Luciferase reporter assay and chromatin immunoprecipitation were utilized to determine whether Isl1 is a direct downstream target of Tcf7l2 TCF7L2DN adenovirus infection and siRNA-mediated Isl1 knockdown on β-cell gene expression were compared. Furthermore, Isl1 knockdown on GLP-1 stimulated β-catenin S675 phosphorylation and insulin secretion was determined. We found that TCF7L2DN repressed ISL1 levels in βTCFDN islets and the INS-1 832/13 cell line. Wnt stimulators enhanced Isl1 promoter activity and binding of TCF7L2 on Isl1 promoter. TCF7L2DN adenovirus infection and Isl1 knockdown generated similar repression on expression of β-cell genes, including the ones that encode GLUT2 and GLP-1 receptor. Either TCF7L2DN adenovirus infection or Isl1 knockdown attenuated GLP-1-stimulated β-catenin S675 phosphorylation in INS-1 832/13 cells or mouse islets and GLP-1 stimulated insulin secretion in INS-1 832/13 or MIN6 cells. Our observations support the existence of TCF7L2-ISL1 transcriptional network, and we suggest that this network also mediates β-cell function of GLP-1.
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Affiliation(s)
- Weijuan Shao
- Division of Advanced DiagnosticsToronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Vivian Szeto
- Department of PhysiologyUniversity of Toronto, Medical Sciences Building, Toronto, Ontario, Canada
| | - Zhuolun Song
- Department of PhysiologyUniversity of Toronto, Medical Sciences Building, Toronto, Ontario, Canada
| | - Lili Tian
- Division of Advanced DiagnosticsToronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Zhong-Ping Feng
- Department of PhysiologyUniversity of Toronto, Medical Sciences Building, Toronto, Ontario, Canada
| | - M Cristina Nostro
- Department of PhysiologyUniversity of Toronto, Medical Sciences Building, Toronto, Ontario, Canada
- Division of Experimental TherapeuticsToronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- McEwen Centre for Regenerative MedicineUniversity Health Network, Toronto, Ontario, Canada
| | - Tianru Jin
- Division of Advanced DiagnosticsToronto General Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of PhysiologyUniversity of Toronto, Medical Sciences Building, Toronto, Ontario, Canada
- McEwen Centre for Regenerative MedicineUniversity Health Network, Toronto, Ontario, Canada
- Banting and Best Diabetes CenterUniversity of Toronto, Toronto, Ontario, Canada
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23
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Qin Y, Chen M, Yang Y, Zhou XR, Shao SY, Wang DW, Yuan G. Liraglutide improves hepatic insulin resistance via the canonical Wnt signaling pathway. Mol Med Rep 2018; 17:7372-7380. [PMID: 29568881 DOI: 10.3892/mmr.2018.8737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 11/23/2017] [Indexed: 11/06/2022] Open
Abstract
Liraglutide, a modified form of glucagon‑like peptide‑1 (GLP‑1), is used in the treatment of diabetes mellitus. However, the underlying mechanism by which liraglutide improves liver insulin resistance remains to be elucidated. The proto‑oncogene Wnt (Wnt) signaling pathway has been reported to be associated with glucose and lipid metabolism. Using in vivo and in vitro models of diabetes and insulin resistance, it was investigated whether the beneficial effects of liraglutide on liver glucose metabolism are mediated by the Wnt signaling pathway. The results of the present study demonstrate that body weight, fasting blood glucose, insulin levels and the homeostasis model assessment for insulin resistance were markedly decreased in db/db mice treated with liraglutide compared with control mice. Liraglutide also improved liver morphology and reduced the accumulation of lipid droplets. Furthermore, the expression of glucose-6-phosphatase and phosphoenolpyruvate carboxykinase was downregulated, whereas the expression of phosphorylated forkhead box O1, Wnt signaling pathway‑associated molecules, β‑catenin, transcription factor 7‑like 2 and phosphorylated glycogen synthase kinase-3β was upregulated in the liver of mice treated with liraglutide. In the in vitro study, increased gluconeogenesis and decreased glucose uptake rates were observed in insulin resistant hepatocytes; treatment with liraglutide significantly reversed this effect. Furthermore, transfection of insulin resistant hepatocytes with β‑catenin small interfering RNA attenuated the effects of liraglutide, suggesting that liraglutide improves insulin resistance via activating the β‑catenin/Wnt signaling pathway. The results of the present study suggest a novel mechanism underlying liraglutide‑mediated improvements in insulin resistance in the liver. The Wnt signaling pathway may be a potential therapeutic target for the treatment of altered hepatic physiology in insulin resistance.
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Affiliation(s)
- Yu Qin
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Min Chen
- Department of Geriatrics, The First Hospital of Jiangxia, Wuhan, Hubei 430030, P.R. China
| | - Yan Yang
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Xin-Rong Zhou
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Shi-Ying Shao
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Dao-Wen Wang
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
| | - Gang Yuan
- Department of Internal Medicine, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China
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Sakhneny L, Rachi E, Epshtein A, Guez HC, Wald-Altman S, Lisnyansky M, Khalifa-Malka L, Hazan A, Baer D, Priel A, Weil M, Landsman L. Pancreatic Pericytes Support β-Cell Function in a Tcf7l2-Dependent Manner. Diabetes 2018; 67:437-447. [PMID: 29246974 DOI: 10.2337/db17-0697] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 12/06/2017] [Indexed: 01/13/2023]
Abstract
Polymorphism in TCF7L2, a component of the canonical Wnt signaling pathway, has a strong association with β-cell dysfunction and type 2 diabetes through a mechanism that has yet to be defined. β-Cells rely on cells in their microenvironment, including pericytes, for their proper function. Here, we show that Tcf7l2 activity in pancreatic pericytes is required for β-cell function. Transgenic mice in which Tcf7l2 was selectively inactivated in their pancreatic pericytes exhibited impaired glucose tolerance due to compromised β-cell function and glucose-stimulated insulin secretion. Inactivation of pericytic Tcf7l2 was associated with impaired expression of genes required for β-cell function and maturity in isolated islets. In addition, we identified Tcf7l2-dependent pericytic expression of secreted factors shown to promote β-cell function, including bone morphogenetic protein 4 (BMP4). Finally, we show that exogenous BMP4 is sufficient to rescue the impaired glucose-stimulated insulin secretion of transgenic mice, pointing to a potential mechanism through which pericytic Tcf7l2 activity affects β-cells. To conclude, we suggest that pancreatic pericytes produce secreted factors, including BMP4, in a Tcf7l2-dependent manner to support β-cell function. Our findings thus propose a potential cellular mechanism through which abnormal TCF7L2 activity predisposes individuals to diabetes and implicates abnormalities in the islet microenvironment in this disease.
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Affiliation(s)
- Lina Sakhneny
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Eleonor Rachi
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Alona Epshtein
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Helen C Guez
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shane Wald-Altman
- Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences and the Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Michal Lisnyansky
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Laura Khalifa-Malka
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Adina Hazan
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Daria Baer
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Avi Priel
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Miguel Weil
- Department of Cell Research and Immunology, The George S. Wise Faculty of Life Sciences and the Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Limor Landsman
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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25
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Wang X, Sterr M, Burtscher I, Chen S, Hieronimus A, Machicao F, Staiger H, Häring HU, Lederer G, Meitinger T, Cernilogar FM, Schotta G, Irmler M, Beckers J, Hrabě de Angelis M, Ray M, Wright CVE, Bakhti M, Lickert H. Genome-wide analysis of PDX1 target genes in human pancreatic progenitors. Mol Metab 2018; 9:57-68. [PMID: 29396371 PMCID: PMC5870105 DOI: 10.1016/j.molmet.2018.01.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/05/2018] [Accepted: 01/16/2018] [Indexed: 12/14/2022] Open
Abstract
Objective Homozygous loss-of-function mutations in the gene coding for the homeobox transcription factor (TF) PDX1 leads to pancreatic agenesis, whereas heterozygous mutations can cause Maturity-Onset Diabetes of the Young 4 (MODY4). Although the function of Pdx1 is well studied in pre-clinical models during insulin-producing β-cell development and homeostasis, it remains elusive how this TF controls human pancreas development by regulating a downstream transcriptional program. Also, comparative studies of PDX1 binding patterns in pancreatic progenitors and adult β-cells have not been conducted so far. Furthermore, many studies reported the association between single nucleotide polymorphisms (SNPs) and T2DM, and it has been shown that islet enhancers are enriched in T2DM-associated SNPs. Whether regions, harboring T2DM-associated SNPs are PDX1 bound and active at the pancreatic progenitor stage has not been reported so far. Methods In this study, we have generated a novel induced pluripotent stem cell (iPSC) line that efficiently differentiates into human pancreatic progenitors (PPs). Furthermore, PDX1 and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify PDX1 transcriptional targets and active enhancer and promoter regions. To address potential differences in the function of PDX1 during development and adulthood, we compared PDX1 binding profiles from PPs and adult islets. Moreover, combining ChIP-seq and GWAS meta-analysis data we identified T2DM-associated SNPs in PDX1 binding sites and active chromatin regions. Results ChIP-seq for PDX1 revealed a total of 8088 PDX1-bound regions that map to 5664 genes in iPSC-derived PPs. The PDX1 target regions include important pancreatic TFs, such as PDX1 itself, RFX6, HNF1B, and MEIS1, which were activated during the differentiation process as revealed by the active chromatin mark H3K27ac and mRNA expression profiling, suggesting that auto-regulatory feedback regulation maintains PDX1 expression and initiates a pancreatic TF program. Remarkably, we identified several PDX1 target genes that have not been reported in the literature in human so far, including RFX3, required for ciliogenesis and endocrine differentiation in mouse, and the ligand of the Notch receptor DLL1, which is important for endocrine induction and tip-trunk patterning. The comparison of PDX1 profiles from PPs and adult human islets identified sets of stage-specific target genes, associated with early pancreas development and adult β-cell function, respectively. Furthermore, we found an enrichment of T2DM-associated SNPs in active chromatin regions from iPSC-derived PPs. Two of these SNPs fall into PDX1 occupied sites that are located in the intronic regions of TCF7L2 and HNF1B. Both of these genes are key transcriptional regulators of endocrine induction and mutations in cis-regulatory regions predispose to diabetes. Conclusions Our data provide stage-specific target genes of PDX1 during in vitro differentiation of stem cells into pancreatic progenitors that could be useful to identify pathways and molecular targets that predispose for diabetes. In addition, we show that T2DM-associated SNPs are enriched in active chromatin regions at the pancreatic progenitor stage, suggesting that the susceptibility to T2DM might originate from imperfect execution of a β-cell developmental program. PDX1 ChIP-seq analysis revealed 5664 target genes in human pancreatic progenitors, including unreported target genes. Comparison of PDX1 profiles from PPs and adult human islets identified stage-specific PDX1 target gene sets. T2DM-associated SNPs are enriched in active chromatin regions from iPSC-derived PPs. Three SNPs fall into PDX1 occupied sites, located in intronic regions of the developmental regulatory TFs TCF7L2 and HNF1B.
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Affiliation(s)
- Xianming Wang
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Michael Sterr
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Ingo Burtscher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Shen Chen
- iPS and Cancer Research Unit, Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Anja Hieronimus
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Fausto Machicao
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Harald Staiger
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Institute of Pharmaceutical Sciences, Department of Pharmacy and Biochemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Gabriele Lederer
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Filippo M Cernilogar
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Gunnar Schotta
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Michael Ray
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Christopher V E Wright
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
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26
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Ferreira MC, da Silva MER, Fukui RT, Arruda-Marques MDC, dos Santos RF. TCF7L2 correlation in both insulin secretion and postprandial insulin sensitivity. Diabetol Metab Syndr 2018; 10:37. [PMID: 29736187 PMCID: PMC5922313 DOI: 10.1186/s13098-018-0338-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/17/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The TCF7L2 rs7903146 variant is strongly associated with type 2 diabetes mellitus (T2DM). However, the mechanisms involved in this association remain unknown and may include extrapancreatic effects. The aim of this study was to perform a metabolic characterization of T2DM patients with and without the TCF7L2 rs7903146 risk T allele and analyze some influences of the TCF7L2 genotype on glucose metabolism. METHODS Patients with T2DM (n = 162) were genotyped for the TCF7L2 rs7903146 single nucleotide polymorphism. Individuals with CT/TT and CC genotypes were compared regarding basal serum levels of glucose, glycosylated hemoglobin A1C, HDL, uric acid, insulin, and C-peptide. A subset of 56 individuals was evaluated during a 500-calorie mixed-meal test with measurements of glucose, insulin, proinsulin, C-peptide and glucagon. Additional secondary assessments included determination of insulinogenic index (IGI30), and insulin sensitivity (%S) and resistance (IR) by Homeostatic model assessment (HOMA). RESULTS Patients with the CT/TT genotype showed lower baseline plasma concentrations of C-peptide when compared with those with the CC genotype. Of the 56 individuals who participated in the mixed-meal test, 26 and 30 had the CC and CT/TT genotypes, respectively. CT/TT subjects, compared with CC individuals, had higher post prandial plasma levels of insulin and C-peptide at 30-120 min (p < 0.05) and proinsulin at 45-240 min (p < 0.05). Interestingly CT/TT individuals presented at baseline higher %S (p = 0.021), and lower IR (p = 0.020) than CC individuals. No significant differences in IGI30 values were observed between groups. CONCLUSIONS The T2DM individuals carrying the rs7903146 T allele of the TCF7L2 gene presented higher IR pattern in response to a mix-meal test, different of beta cell function at baseline assessed by C-peptide levels which was lower, and Homa-IR was lower when comparing with non-carriers.
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Affiliation(s)
- Mari Cassol Ferreira
- Laboratory of Medical Investigation LIM-18, Division of Endocrinology, School of Medicine, University of Sao Paulo, Av Dr Arnaldo, 455 room 3324, Sao Paulo, SP 01246903 Brazil
- School of Medicine of Unochapecó University, Bairro Efapi, Chapecó, SC 89809-900 Brazil
| | - Maria Elizabeth Rossi da Silva
- Laboratory of Medical Investigation LIM-18, Division of Endocrinology, School of Medicine, University of Sao Paulo, Av Dr Arnaldo, 455 room 3324, Sao Paulo, SP 01246903 Brazil
| | - Rosa Tsuneshiro Fukui
- Laboratory of Medical Investigation LIM-18, Division of Endocrinology, School of Medicine, University of Sao Paulo, Av Dr Arnaldo, 455 room 3324, Sao Paulo, SP 01246903 Brazil
| | - Maria do Carmo Arruda-Marques
- Laboratory of Medical Investigation LIM-18, Division of Endocrinology, School of Medicine, University of Sao Paulo, Av Dr Arnaldo, 455 room 3324, Sao Paulo, SP 01246903 Brazil
| | - Rosa Ferreira dos Santos
- Laboratory of Medical Investigation LIM-18, Division of Endocrinology, School of Medicine, University of Sao Paulo, Av Dr Arnaldo, 455 room 3324, Sao Paulo, SP 01246903 Brazil
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Oh YS, Jun HS. Effects of Glucagon-Like Peptide-1 on Oxidative Stress and Nrf2 Signaling. Int J Mol Sci 2017; 19:ijms19010026. [PMID: 29271910 PMCID: PMC5795977 DOI: 10.3390/ijms19010026] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 12/16/2022] Open
Abstract
Oxidative cellular damage caused by free radicals is known to contribute to the pathogenesis of various diseases such as cancer, diabetes, and neurodegenerative diseases, as well as to aging. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein1 (Keap1) signaling pathways play an important role in preventing stresses including oxidative and inflammatory stresses. Nrf2 is a master regulator of cellular stress responses, induces the expression of antioxidant and detoxification enzymes, and protects against oxidative stress-induced cell damage. Glucagon-like peptide-1 (GLP-1) is an incretin hormone, which was originally found to increase insulin synthesis and secretion. It is now widely accepted that GLP-1 has multiple functions beyond glucose control in various tissues and organs including brain, kidney, and heart. GLP-1 and GLP-1 receptor agonists are known to be effective in many chronic diseases, including diabetes, via antioxidative mechanisms. In this review, we summarize the current knowledge regarding the role of GLP-1 in the protection against oxidative damage and the activation of the Nrf2 signaling pathway.
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Affiliation(s)
- Yoon Sin Oh
- Department of Food and Nutrition, Eulji University, Seongnam 13135, Korea.
| | - Hee-Sook Jun
- College of Pharmacy and Gachon Institute of Pharmaceutical Science, Gachon University, Incheon 21936, Korea.
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon 21999, Korea.
- Gachon Medical Research Institute, Gil Hospital, Incheon 21565, Korea.
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Abstract
PURPOSE OF REVIEW Deciphering the mechanisms of type 2 diabetes (T2DM) risk loci can greatly inform on disease pathology. This review discusses current knowledge of mechanisms through which genetic variants influence T2DM risk and considerations for future studies. RECENT FINDINGS Over 100 T2DM risk loci to date have been identified. Candidate causal variants at risk loci map predominantly to non-coding sequence. Physiological, epigenomic and gene expression data suggest that variants at many known T2DM risk loci affect pancreatic islet regulation, although variants at other loci also affect protein function and regulatory processes in adipose, pre-adipose, liver, skeletal muscle and brain. The effects of T2DM variants on regulatory activity in these tissues appear largely, but not exclusively, due to altered transcription factor binding. Putative target genes of T2DM variants have been defined at an increasing number of loci and some, such as FTO, may entail several genes and multiple tissues. Gene networks in islets and adipocytes have been implicated in T2DM risk, although the molecular pathways of risk genes remain largely undefined. Efforts to fully define the mechanisms of T2DM risk loci are just beginning. Continued identification of risk mechanisms will benefit from combining genetic fine-mapping with detailed phenotypic association data, high-throughput epigenomics data from diabetes-relevant tissue, functional screening of candidate genes and genome editing of cellular and animal models.
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Affiliation(s)
- Kyle J Gaulton
- Department of Pediatrics, University of California San Diego, San Diego, CA, 92093, USA.
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29
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Facchinello N, Tarifeño-Saldivia E, Grisan E, Schiavone M, Peron M, Mongera A, Ek O, Schmitner N, Meyer D, Peers B, Tiso N, Argenton F. Tcf7l2 plays pleiotropic roles in the control of glucose homeostasis, pancreas morphology, vascularization and regeneration. Sci Rep 2017; 7:9605. [PMID: 28851992 PMCID: PMC5575064 DOI: 10.1038/s41598-017-09867-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 07/06/2017] [Indexed: 11/10/2022] Open
Abstract
Type 2 diabetes (T2D) is a disease characterized by impaired insulin secretion. The Wnt signaling transcription factor Tcf7l2 is to date the T2D-associated gene with the largest effect on disease susceptibility. However, the mechanisms by which TCF7L2 variants affect insulin release from β-cells are not yet fully understood. By taking advantage of a tcf7l2 zebrafish mutant line, we first show that these animals are characterized by hyperglycemia and impaired islet development. Moreover, we demonstrate that the zebrafish tcf7l2 gene is highly expressed in the exocrine pancreas, suggesting potential bystander effects on β-cell growth, differentiation and regeneration. Finally, we describe a peculiar vascular phenotype in tcf7l2 mutant larvae, characterized by significant reduction in the average number and diameter of pancreatic islet capillaries. Overall, the zebrafish Tcf7l2 mutant, characterized by hyperglycemia, pancreatic and vascular defects, and reduced regeneration proves to be a suitable model to study the mechanism of action and the pleiotropic effects of Tcf7l2, the most relevant T2D GWAS hit in human populations.
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Affiliation(s)
| | - Estefania Tarifeño-Saldivia
- Laboratory of Zebrafish Development and Disease Models, GIGA-R, University of Liege, B-4000, Sart Tilman, Belgium
| | - Enrico Grisan
- Department of Information Engineering, University of Padova, I-35131, Padova, Italy
| | - Marco Schiavone
- Department of Biology, University of Padova, I-35131, Padova, Italy
| | - Margherita Peron
- Department of Biology, University of Padova, I-35131, Padova, Italy
| | | | - Olivier Ek
- Department of Biology, University of Padova, I-35131, Padova, Italy
| | - Nicole Schmitner
- Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, A-6020, Innsbruck, Austria
| | - Dirk Meyer
- Institute of Molecular Biology, CMBI, Leopold-Franzens-University Innsbruck, A-6020, Innsbruck, Austria
| | - Bernard Peers
- Laboratory of Zebrafish Development and Disease Models, GIGA-R, University of Liege, B-4000, Sart Tilman, Belgium
| | - Natascia Tiso
- Department of Biology, University of Padova, I-35131, Padova, Italy.
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Wood AR, Jonsson A, Jackson AU, Wang N, van Leewen N, Palmer ND, Kobes S, Deelen J, Boquete-Vilarino L, Paananen J, Stančáková A, Boomsma DI, de Geus EJC, Eekhoff EMW, Fritsche A, Kramer M, Nijpels G, Simonis-Bik A, van Haeften TW, Mahajan A, Boehnke M, Bergman RN, Tuomilehto J, Collins FS, Mohlke KL, Banasik K, Groves CJ, McCarthy MI, Pearson ER, Natali A, Mari A, Buchanan TA, Taylor KD, Xiang AH, Gjesing AP, Grarup N, Eiberg H, Pedersen O, Chen YD, Laakso M, Norris JM, Smith U, Wagenknecht LE, Baier L, Bowden DW, Hansen T, Walker M, Watanabe RM, 't Hart LM, Hanson RL, Frayling TM. A Genome-Wide Association Study of IVGTT-Based Measures of First-Phase Insulin Secretion Refines the Underlying Physiology of Type 2 Diabetes Variants. Diabetes 2017; 66:2296-2309. [PMID: 28490609 PMCID: PMC5521867 DOI: 10.2337/db16-1452] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 05/02/2017] [Indexed: 01/19/2023]
Abstract
Understanding the physiological mechanisms by which common variants predispose to type 2 diabetes requires large studies with detailed measures of insulin secretion and sensitivity. Here we performed the largest genome-wide association study of first-phase insulin secretion, as measured by intravenous glucose tolerance tests, using up to 5,567 individuals without diabetes from 10 studies. We aimed to refine the mechanisms of 178 known associations between common variants and glycemic traits and identify new loci. Thirty type 2 diabetes or fasting glucose-raising alleles were associated with a measure of first-phase insulin secretion at P < 0.05 and provided new evidence, or the strongest evidence yet, that insulin secretion, intrinsic to the islet cells, is a key mechanism underlying the associations at the HNF1A, IGF2BP2, KCNQ1, HNF1B, VPS13C/C2CD4A, FAF1, PTPRD, AP3S2, KCNK16, MAEA, LPP, WFS1, and TMPRSS6 loci. The fasting glucose-raising allele near PDX1, a known key insulin transcription factor, was strongly associated with lower first-phase insulin secretion but has no evidence for an effect on type 2 diabetes risk. The diabetes risk allele at TCF7L2 was associated with a stronger effect on peak insulin response than on C-peptide-based insulin secretion rate, suggesting a possible additional role in hepatic insulin clearance or insulin processing. In summary, our study provides further insight into the mechanisms by which common genetic variation influences type 2 diabetes risk and glycemic traits.
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Affiliation(s)
- Andrew R Wood
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon and Exeter Hospital, Exeter, U.K
| | - Anna Jonsson
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne U Jackson
- Department of Biostatistics and Center for Statistical Genetics, University of Michigan, Ann Arbor, MI
| | - Nan Wang
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Diabetes & Obesity Research Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Nienke van Leewen
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Nicholette D Palmer
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC
| | - Sayuko Kobes
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
| | - Joris Deelen
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Lorena Boquete-Vilarino
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon and Exeter Hospital, Exeter, U.K
| | - Jussi Paananen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Alena Stančáková
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Dorret I Boomsma
- Department of Biological Psychology, VU University, Amsterdam, the Netherlands
| | - Eco J C de Geus
- Department of Biological Psychology, VU University, Amsterdam, the Netherlands
| | - Elisabeth M W Eekhoff
- Diabetes Center, Internal Medicine Unit, VU University Medical Center, Amsterdam, the Netherlands
| | - Andreas Fritsche
- Division of Endocrinology, Diabetology, Angiology, Nephrology and Clinical Chemistry, Department of Internal Medicine IV, University of Tübingen, Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich, University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany
| | - Mark Kramer
- Diabetes Center, Internal Medicine Unit, VU University Medical Center, Amsterdam, the Netherlands
| | - Giel Nijpels
- EMGO+ Institute for Health and Care Research, VU University Medical Center, Department of General Practice, Amsterdam, the Netherlands
| | - Annemarie Simonis-Bik
- Diabetes Center, Internal Medicine Unit, VU University Medical Center, Amsterdam, the Netherlands
| | - Timon W van Haeften
- Department of Internal Medicine, Utrecht University Medical Center, Utrecht, the Netherlands
| | - Anubha Mahajan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - Michael Boehnke
- Department of Biostatistics and Center for Statistical Genetics, University of Michigan, Ann Arbor, MI
| | - Richard N Bergman
- Diabetes & Obesity Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Jaakko Tuomilehto
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
- Dasman Diabetes Institute, Dasman, Kuwait
- Department of Clinical Neurosciences and Preventive Medicine, Danube University Krems, Krems, Austria
- Saudi Diabetes Research Group, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Francis S Collins
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Karen L Mohlke
- Department of Genetics, University of North Carolina, Chapel Hill, NC
| | - Karina Banasik
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Christopher J Groves
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Oxford, U.K
| | - Mark I McCarthy
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Oxford, U.K
- Oxford Biomedical Research Centre, National Institute for Health Research, Churchill Hospital, Oxford, U.K
| | | | - Andrea Natali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Andrea Mari
- Institute of Neuroscience, National Research Council, Padova, Italy
| | - Thomas A Buchanan
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Diabetes & Obesity Research Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Kent D Taylor
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
- Department of Pediatrics, University of California, Los Angeles, Los Angeles, CA
| | - Anny H Xiang
- Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, CA
| | - Anette P Gjesing
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Grarup
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hans Eiberg
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yii-Derr Chen
- Institute for Translational Genomics and Population Sciences, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA
| | - Markku Laakso
- Department of Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Jill M Norris
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, CO
| | - Ulf Smith
- Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | - Leslie Baier
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
| | - Donald W Bowden
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC
| | - Torben Hansen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mark Walker
- Institute of Cellular Medicine, Newcastle University, Newcastle, U.K.
| | - Richard M Watanabe
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Diabetes & Obesity Research Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, CA
| | - Leen M 't Hart
- Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, the Netherlands
- Section of Molecular Epidemiology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Epidemiology and Biostatistics, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, the Netherlands
| | - Robert L Hanson
- Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, AZ
| | - Timothy M Frayling
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon and Exeter Hospital, Exeter, U.K.
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da Silva Xavier G, Mondragon A, Mourougavelou V, Cruciani-Guglielmacci C, Denom J, Herrera PL, Magnan C, Rutter GA. Pancreatic alpha cell-selective deletion of Tcf7l2 impairs glucagon secretion and counter-regulatory responses to hypoglycaemia in mice. Diabetologia 2017; 60:1043-1050. [PMID: 28343277 PMCID: PMC5423960 DOI: 10.1007/s00125-017-4242-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/15/2017] [Indexed: 01/19/2023]
Abstract
AIMS/HYPOTHESIS Transcription factor 7-like 2 (TCF7L2) is a high mobility group (HMG) box-containing transcription factor and downstream effector of the Wnt signalling pathway. SNPs in the TCF7L2 gene have previously been associated with an increased risk of type 2 diabetes in genome-wide association studies. In animal studies, loss of Tcf7l2 function is associated with defective islet beta cell function and survival. Here, we explore the role of TCF7L2 in the control of the counter-regulatory response to hypoglycaemia by generating mice with selective deletion of the Tcf7l2 gene in pancreatic alpha cells. METHODS Alpha cell-selective deletion of Tcf7l2 was achieved by crossing mice with floxed Tcf7l2 alleles to mice bearing a Cre recombinase transgene driven by the preproglucagon promoter (PPGCre), resulting in Tcf7l2AKO mice. Glucose homeostasis and hormone secretion in vivo and in vitro, and islet cell mass were measured using standard techniques. RESULTS While glucose tolerance was unaffected in Tcf7l2AKO mice, glucose infusion rates were increased (AUC for glucose during the first 60 min period of hyperinsulinaemic-hypoglycaemic clamp test was increased by 1.98 ± 0.26-fold [p < 0.05; n = 6] in Tcf7l2AKO mice vs wild-type mice) and glucagon secretion tended to be lower (plasma glucagon: 0.40 ± 0.03-fold vs wild-type littermate controls [p < 0.01; n = 6]). Tcf7l2AKO mice displayed reduced fasted plasma glucose concentration. Glucagon release at low glucose was impaired in islets isolated from Tcf7l2AKO mice (0.37 ± 0.02-fold vs islets from wild-type littermate control mice [p < 0.01; n = 6). Alpha cell mass was also reduced (72.3 ± 20.3% [p < 0.05; n = 7) in Tcf7l2AKO mice compared with wild-type mice. CONCLUSIONS/INTERPRETATION The present findings demonstrate an alpha cell-autonomous role for Tcf7l2 in the control of pancreatic glucagon secretion and the maintenance of alpha cell mass and function.
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Affiliation(s)
- Gabriela da Silva Xavier
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, W12 0NN, UK.
| | - Angeles Mondragon
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, W12 0NN, UK
| | - Vishnou Mourougavelou
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, W12 0NN, UK
| | | | - Jessica Denom
- Université Paris Diderot Paris 7 - CNRS UMR 8251, Paris, France
| | - Pedro Luis Herrera
- Department of Genetic Medicine & Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | | | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, W12 0NN, UK
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Nagalski A, Kozinski K, Wisniewska MB. Metabolic pathways in the periphery and brain: Contribution to mental disorders? Int J Biochem Cell Biol 2016; 80:19-30. [PMID: 27644152 DOI: 10.1016/j.biocel.2016.09.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 09/14/2016] [Accepted: 09/15/2016] [Indexed: 12/20/2022]
Abstract
The association between mental disorders and diabetes has a long history. Recent large-scale, well-controlled epidemiological studies confirmed a link between diabetes and psychiatric illnesses. The scope of this review is to summarize our current understanding of this relationship from a molecular perspective. We first discuss the potential contribution of diabetes-associated metabolic impairments to the etiology of mental conditions. Then, we focus on possible shared molecular risk factors and mechanisms. Simple comorbidity, shared susceptibility loci, and common pathophysiological processes in diabetes and mental illnesses have changed our traditional way of thinking about mental illness. We conclude that schizophrenia and affective disorders are not limited to an imbalance in dopaminergic and serotoninergic neurotransmission in the brain. They are also systemic disorders that can be considered, to some extent, as metabolic disorders.
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Affiliation(s)
- Andrzej Nagalski
- Laboratory of Molecular Neurobiology, Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland
| | - Kamil Kozinski
- Laboratory of Molecular Neurobiology, Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland
| | - Marta B Wisniewska
- Laboratory of Molecular Neurobiology, Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland.
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33
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Mehta ZB, Fine N, Pullen TJ, Cane MC, Hu M, Chabosseau P, Meur G, Velayos-Baeza A, Monaco AP, Marselli L, Marchetti P, Rutter GA. Changes in the expression of the type 2 diabetes-associated gene VPS13C in the β-cell are associated with glucose intolerance in humans and mice. Am J Physiol Endocrinol Metab 2016; 311:E488-507. [PMID: 27329800 PMCID: PMC5005967 DOI: 10.1152/ajpendo.00074.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 06/20/2016] [Indexed: 12/31/2022]
Abstract
Single nucleotide polymorphisms (SNPs) close to the VPS13C, C2CD4A and C2CD4B genes on chromosome 15q are associated with impaired fasting glucose and increased risk of type 2 diabetes. eQTL analysis revealed an association between possession of risk (C) alleles at a previously implicated causal SNP, rs7163757, and lowered VPS13C and C2CD4A levels in islets from female (n = 40, P < 0.041) but not from male subjects. Explored using promoter-reporter assays in β-cells and other cell lines, the risk variant at rs7163757 lowered enhancer activity. Mice deleted for Vps13c selectively in the β-cell were generated by crossing animals bearing a floxed allele at exon 1 to mice expressing Cre recombinase under Ins1 promoter control (Ins1Cre). Whereas Vps13c(fl/fl):Ins1Cre (βVps13cKO) mice displayed normal weight gain compared with control littermates, deletion of Vps13c had little effect on glucose tolerance. Pancreatic histology revealed no significant change in β-cell mass in KO mice vs. controls, and glucose-stimulated insulin secretion from isolated islets was not altered in vitro between control and βVps13cKO mice. However, a tendency was observed in female null mice for lower insulin levels and β-cell function (HOMA-B) in vivo. Furthermore, glucose-stimulated increases in intracellular free Ca(2+) were significantly increased in islets from female KO mice, suggesting impaired Ca(2+) sensitivity of the secretory machinery. The present data thus provide evidence for a limited role for changes in VPS13C expression in conferring altered disease risk at this locus, particularly in females, and suggest that C2CD4A may also be involved.
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Affiliation(s)
- Zenobia B Mehta
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Nicholas Fine
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Timothy J Pullen
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Matthew C Cane
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Ming Hu
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | - Gargi Meur
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom
| | | | - Anthony P Monaco
- Wellcome Trust Centre for Human Genetics, Oxford, United Kingdom; and
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Imperial College London, London, United Kingdom;
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Zhou Y, Oskolkov N, Shcherbina L, Ratti J, Kock KH, Su J, Martin B, Oskolkova MZ, Göransson O, Bacon J, Li W, Bucciarelli S, Cilio C, Brazma A, Thatcher B, Rung J, Wierup N, Renström E, Groop L, Hansson O. HMGB1 binds to the rs7903146 locus in TCF7L2 in human pancreatic islets. Mol Cell Endocrinol 2016; 430:138-45. [PMID: 26845344 DOI: 10.1016/j.mce.2016.01.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 01/19/2016] [Accepted: 01/28/2016] [Indexed: 02/03/2023]
Abstract
The intronic SNP rs7903146 in the T-cell factor 7-like 2 gene (TCF7L2) is the common genetic variant most highly associated with Type 2 diabetes known to date. The risk T-allele is located in an open chromatin region specific to human pancreatic islets of Langerhans, thereby accessible for binding of regulatory proteins. The risk T-allele locus exhibits stronger enhancer activity compared to the non-risk C-allele. The aim of this study was to identify transcriptional regulators that bind the open chromatin region in the rs7903146 locus and thereby potentially regulate TCF7L2 expression and activity. Using affinity chromatography followed by Edman sequencing, we identified one candidate regulatory protein, i.e. high-mobility group protein B1 (HMGB1). The binding of HMGB1 to the rs7903146 locus was confirmed in pancreatic islets from human deceased donors, in HCT116 and in HEK293 cell lines using: (i) protein purification on affinity columns followed by Western blot, (ii) chromatin immunoprecipitation followed by qPCR and (iii) electrophoretic mobility shift assay. The results also suggested that HMGB1 might have higher binding affinity to the C-allele of rs7903146 compared to the T-allele, which was supported in vitro using Dynamic Light Scattering, possibly in a tissue-specific manner. The functional consequence of HMGB1 depletion in HCT116 and INS1 cells was reduced insulin and TCF7L2 mRNA expression, TCF7L2 transcriptional activity and glucose stimulated insulin secretion. These findings suggest that the rs7903146 locus might exert its enhancer function by interacting with HMGB1 in an allele dependent manner.
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Affiliation(s)
- Yuedan Zhou
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Nikolay Oskolkov
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Liliya Shcherbina
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Joyce Ratti
- Department of Biochemistry, University of Cambridge, CB2 1GA, Cambridge, UK
| | - Kian-Hong Kock
- Department of Biochemistry, University of Cambridge, CB2 1GA, Cambridge, UK
| | - Jing Su
- European Bioinformatics Institute, Functional Genomics, Hinxton, Cambridge CB10 1SD, UK
| | - Brian Martin
- National Institute of Mental Health NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Olga Göransson
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Julie Bacon
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Weimin Li
- Department of Physical Chemistry, Lund University, Lund, 22100, Sweden
| | | | - Corrado Cilio
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Alvis Brazma
- European Bioinformatics Institute, Functional Genomics, Hinxton, Cambridge CB10 1SD, UK
| | - Bradley Thatcher
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Johan Rung
- European Bioinformatics Institute, Functional Genomics, Hinxton, Cambridge CB10 1SD, UK
| | - Nils Wierup
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Erik Renström
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Leif Groop
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden
| | - Ola Hansson
- Department of Clinical Sciences, CRC, Lund University, Malmö, 20502, Sweden.
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Sekar R, Singh K, Arokiaraj AWR, Chow BKC. Pharmacological Actions of Glucagon-Like Peptide-1, Gastric Inhibitory Polypeptide, and Glucagon. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 326:279-341. [PMID: 27572131 DOI: 10.1016/bs.ircmb.2016.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Glucagon family of peptide hormones is a group of structurally related brain-gut peptides that exert their pleiotropic actions through interactions with unique members of class B1 G protein-coupled receptors (GPCRs). They are key regulators of hormonal homeostasis and are important drug targets for metabolic disorders such as type-2 diabetes mellitus (T2DM), obesity, and dysregulations of the nervous systems such as migraine, anxiety, depression, neurodegeneration, psychiatric disorders, and cardiovascular diseases. The current review aims to provide a detailed overview of the current understanding of the pharmacological actions and therapeutic advances of three members within this family including glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP), and glucagon.
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Affiliation(s)
- R Sekar
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - K Singh
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - A W R Arokiaraj
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - B K C Chow
- School of Biological Sciences, University of Hong Kong, Hong Kong, China.
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36
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Jin T. Current Understanding on Role of the Wnt Signaling Pathway Effector TCF7L2 in Glucose Homeostasis. Endocr Rev 2016; 37:254-77. [PMID: 27159876 DOI: 10.1210/er.2015-1146] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The role of the Wnt signaling pathway in metabolic homeostasis has drawn our intensive attention, especially after the genome-wide association study discovery that certain polymorphisms of its key effector TCF7L2 are strongly associated with the susceptibility to type 2 diabetes. For a decade, great efforts have been made in determining the function of TCF7L2 in various metabolic organs, which have generated both considerable achievements and disputes. In this review, I will briefly introduce the canonical Wnt signaling pathway, focusing on its effector β-catenin/TCF, including emphasizing the bidirectional feature of TCFs and β-catenin post-translational modifications. I will then summarize the observations on the association between TCF7L2 polymorphisms and type 2 diabetes risk. The main content, however, is on the intensive functional exploration of the metabolic role of TCF7L2, including the disputes generated on determining its role in the pancreas and liver with various transgenic mouse lines. Finally, I will discuss those achievements and disputes and present my future perspectives.
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Affiliation(s)
- Tianru Jin
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON M5G 2C4, Canada
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37
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Staiger H, Schaeffeler E, Schwab M, Häring HU. Pharmacogenetics: Implications for Modern Type 2 Diabetes Therapy. Rev Diabet Stud 2016; 12:363-76. [PMID: 27111121 DOI: 10.1900/rds.2015.12.363] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Many clinical treatment studies have reported remarkable interindividual variability in the response to pharmaceutical drugs, and uncovered the existence of inadequate treatment response, non-response, and even adverse drug reactions. Pharmacogenetics addresses the impact of genetic variants on treatment outcome including side-effects. In recent years, it has also entered the field of clinical diabetes research. In modern type 2 diabetes therapy, metformin is established as first-line drug. The latest pharmaceutical developments, including incretin mimetics, dipeptidyl peptidase 4 inhibitors (gliptins), and sodium/glucose cotransporter 2 inhibitors (gliflozins), are currently experiencing a marked increase in clinical use, while the prescriptions of α-glucosidase inhibitors, sulfonylureas, meglitinides (glinides), and thiazolidinediones (glitazones) are declining, predominantly because of reported side-effects. This review summarizes the current knowledge about gene-drug interactions observed in therapy studies with the above drugs. We report drug interactions with candidate genes involved in the pharmacokinetics (e.g., drug transporters) and pharmacodynamics (drug targets and downstream signaling steps) of the drugs, with known type 2 diabetes risk genes and previously unknown genes derived from hypothesis-free approaches such as genome-wide association studies. Moreover, some new and promising candidate genes for future pharmacogenetic assessment are highlighted. Finally, we critically appraise the current state of type 2 diabetes pharmacogenetics in the light of its impact on therapeutic decisions, and we refer to major problems, and make suggestions for future efforts in this field to help improve the clinical relevance of the results, and to establish genetically determined treatment failure.
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Affiliation(s)
- Harald Staiger
- Interfaculty Centre for Pharmacogenomics and Pharma Research at the University of Tübingen, Tübingen, Germany
| | - Elke Schaeffeler
- Interfaculty Centre for Pharmacogenomics and Pharma Research at the University of Tübingen, Tübingen, Germany
| | - Matthias Schwab
- Interfaculty Centre for Pharmacogenomics and Pharma Research at the University of Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- Interfaculty Centre for Pharmacogenomics and Pharma Research at the University of Tübingen, Tübingen, Germany
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Willmann SJ, Mueller NS, Engert S, Sterr M, Burtscher I, Raducanu A, Irmler M, Beckers J, Sass S, Theis FJ, Lickert H. The global gene expression profile of the secondary transition during pancreatic development. Mech Dev 2016; 139:51-64. [DOI: 10.1016/j.mod.2015.11.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 12/20/2022]
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Yang L, Yao D, Yang H, Wei Y, Peng Y, Ding Y, Shu L. Puerarin Protects Pancreatic β-Cells in Obese Diabetic Mice via Activation of GLP-1R Signaling. Mol Endocrinol 2016; 30:361-71. [PMID: 26789107 DOI: 10.1210/me.2015-1213] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Diabetes is characterized by a loss and dysfunction of the β-cell. Glucagon-like peptide 1 receptor (GLP-1R) signaling plays an important role in β-cell survival and function. It is meaningful to identify promising agents from natural products which might activate GLP-1R signaling. In this study, puerarin, a diet isoflavone, was evaluated its beneficial effects on β-cell survival and GLP-1R pathway. We showed that puerarin reduced the body weight gain, normalized blood glucose, and improved glucose tolerance in high-fat diet-induced and db/db diabetic mice. Most importantly, increased β-cell mass and β-cell proliferation but decreased β-cell apoptosis were observed in puerarin-treated diabetic mice as examined by immunostaining of mice pancreatic sections. The protective effect of puerarin on β-cell survival was confirmed in isolated mouse islets treated with high glucose. Further mechanism studies showed that the circulating level of GLP-1 in mice was unaffected by puerarin. However, puerarin enhanced GLP-1R signaling by up-regulating expressions of GLP-1R and pancreatic and duodenal homeobox 1, which subsequently led to protein kinase B (Akt) activation but forkhead box O1 inactivation, and promoted β-cell survival. The protective effect of puerarin was remarkably suppressed by Exendin(9-39), an antagonist of GLP-1R. Our study demonstrated puerarin improved glucose homeostasis in obese diabetic mice and identified a novel role of puerarin in protecting β-cell survival by mechanisms involving activation of GLP-1R signaling and downstream targets.
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Affiliation(s)
- Lei Yang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Dongdong Yao
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Haiyuan Yang
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Yingjie Wei
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Yunru Peng
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Yongfang Ding
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
| | - Luan Shu
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Nanjing University of Chinese Medicine, Nanjing, 210028 China; Key Laboratory of New Drug Delivery System of Chinese Materia Medica (L.Y., D.Y., Y.W., Y.P., Y.D., L.S.), Jiangsu Province Academy of Traditional Chinese Medicine, Nanjing, 210028 China; and Jiangsu Key Laboratory of Xenotransplantation (H.Y.), Nanjing Medical University, Nanjing, 210029 China
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Wnt9a deficiency discloses a repressive role of Tcf7l2 on endocrine differentiation in the embryonic pancreas. Sci Rep 2016; 6:19223. [PMID: 26771085 PMCID: PMC4725895 DOI: 10.1038/srep19223] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/09/2015] [Indexed: 12/16/2022] Open
Abstract
Transcriptional and signaling networks establish complex cross-regulatory interactions that drive cellular differentiation during development. Using microarrays we identified the gene encoding the ligand Wnt9a as a candidate target of Neurogenin3, a basic helix-loop-helix transcription factor that functions as a master regulator of pancreatic endocrine differentiation. Here we show that Wnt9a is expressed in the embryonic pancreas and that its deficiency enhances activation of the endocrine transcriptional program and increases the number of endocrine cells at birth. We identify the gene encoding the endocrine transcription factor Nkx2-2 as one of the most upregulated genes in Wnt9a-ablated pancreases and associate its activation to reduced expression of the Wnt effector Tcf7l2. Accordingly, in vitro studies confirm that Tcf7l2 represses activation of Nkx2-2 by Neurogenin3 and inhibits Nkx2-2 expression in differentiated β-cells. Further, we report that Tcf7l2 protein levels decline upon initiation of endocrine differentiation in vivo, disclosing the downregulation of this factor in the developing endocrine compartment. These findings highlight the notion that modulation of signalling cues by lineage-promoting factors is pivotal for controlling differentiation programs.
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Li Z, Sun F, Zhang Y, Chen H, He N, Chen H, Song P, Wang Y, Yan S, Zheng S. Tacrolimus Induces Insulin Resistance and Increases the Glucose Absorption in the Jejunum: A Potential Mechanism of the Diabetogenic Effects. PLoS One 2015; 10:e0143405. [PMID: 26599323 PMCID: PMC4657894 DOI: 10.1371/journal.pone.0143405] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 10/07/2015] [Indexed: 12/16/2022] Open
Abstract
Background The use of the immunosuppressive drug tacrolimus (TAC) is related to new onset diabetes after transplantation. Herein, we examined the effect of intraperitoneal administered TAC on intestinal glucose absorption in mice. Methods Animals received low, medium, or high dose TAC (0.5, 1, or 5 mg/kg/d, respectively), or 0.9% saline solution (control) for 14 days. Oral glucose tolerance test (OGTT), insulin concentration test, and serum TAC concentration measurements was performed after 14 days of TAC exposure. Plasma insulin was assessed and electrogenic glucose absorption were measured by the sodium-dependent increase of the short-circuit current. Expression levels of the glucose transporters sodium glucose co-transporter (SGLT) 1, glucose transporter (GLUT) 2, and GLUT5 were also determined. Results Oral glucose absorption assessed by OGTT was significantly enhanced in the low, medium, and high groups. Serum insulin was elevated in the medium and high group compared with the control. Moreover, glucose-induced Isc was significantly higher in TAC administrated groups, which indicates that SGLT1 activity increased. Transcription levels and protein abundance of SGLT1 in the experimental groups also increased compared with the control. Conclusions TAC induced insulin resistance and strengthened intestinal glucose absorption by increasing the activity and expression of the glucose transporter, SGLT1.
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Affiliation(s)
- Zhiwei Li
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Fei Sun
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yaohui Zhang
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hao Chen
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ningning He
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hui Chen
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Penghong Song
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yan Wang
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Sheng Yan
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shusen Zheng
- Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
- * E-mail:
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Current understanding and dispute on the function of the Wnt signaling pathway effector TCF7L2 in hepatic gluconeogenesis. Genes Dis 2015; 3:48-55. [PMID: 30258876 PMCID: PMC6147171 DOI: 10.1016/j.gendis.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 10/27/2015] [Indexed: 02/07/2023] Open
Abstract
Approximately 10 years ago, the Wnt signaling pathway effector TCF7L2 (=TCF-4) was recognized as a type 2 diabetes (T2D) risk gene through a genome wide association study (GWAS). As the correlation between TCF7L2 polymorphisms and T2D susceptibility has been reproducibly observed by numerous follow-up investigations among different ethnic groups, great efforts have been made to explore the function of TCF7L2 in metabolic organs including the pancreas, liver and adipose tissues. Although these explorations have enriched our general knowledge on the Wnt signaling cascade in metabolic homeostasis, studies conducted to date have also generated controversial suggestions. Here I will provide a brief review on the Wnt signaling pathway as well as the milestone GWAS discovery and the follow-up studies. I will then discuss the two different opinions on the correlation between TCF7L2 variants and T2D risk, a gain-of-function event versus a loss-of-function event. This will be followed by summarizing the relevant investigations on the metabolic function of hepatic TCF7L2 and presenting our view on the discrepancy and perspectives.
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King A, Bowe J. Animal models for diabetes: Understanding the pathogenesis and finding new treatments. Biochem Pharmacol 2015; 99:1-10. [PMID: 26432954 DOI: 10.1016/j.bcp.2015.08.108] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/26/2015] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus is a lifelong, metabolic disease that is characterised by an inability to maintain normal glucose homeostasis. There are several different forms of diabetes, however the two most common are Type 1 and Type 2 diabetes. Type 1 diabetes is caused by the autoimmune destruction of pancreatic beta cells and a subsequent lack of insulin production, whilst Type 2 diabetes is due to a combination of both insulin resistance and an inability of the beta cells to compensate adequately with increased insulin release. Animal models are increasingly being used to elucidate the mechanisms underlying both Type 1 and Type 2 diabetes as well as to identify and refine novel treatments. However, a wide range of different animal models are currently in use. The majority of these models are suited to addressing certain specific aspects of diabetes research, but may be of little use in other studies. All have pros and cons, and selecting an appropriate model for addressing a specific question is not always a trivial task and will influence the study results and their interpretation. Thus, as the number of available animal models increases it is important to consider the potential roles of these models in the many different aspects of diabetes research. This review gathers information on the currently used experimental animal models of both Type 1 and Type 2 diabetes and evaluates their advantages and disadvantages for research purposes and details the factors that should be taken into account in their use.
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Affiliation(s)
- Aileen King
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Hodgkin Building 2nd Floor, Guy's Campus, King's College London, London SE1 1UL, United Kingdom.
| | - James Bowe
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Hodgkin Building 2nd Floor, Guy's Campus, King's College London, London SE1 1UL, United Kingdom
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Sandoval DA, D'Alessio DA. Physiology of proglucagon peptides: role of glucagon and GLP-1 in health and disease. Physiol Rev 2015; 95:513-48. [PMID: 25834231 DOI: 10.1152/physrev.00013.2014] [Citation(s) in RCA: 286] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The preproglucagon gene (Gcg) is expressed by specific enteroendocrine cells (L-cells) of the intestinal mucosa, pancreatic islet α-cells, and a discrete set of neurons within the nucleus of the solitary tract. Gcg encodes multiple peptides including glucagon, glucagon-like peptide-1, glucagon-like peptide-2, oxyntomodulin, and glicentin. Of these, glucagon and GLP-1 have received the most attention because of important roles in glucose metabolism, involvement in diabetes and other disorders, and application to therapeutics. The generally accepted model is that GLP-1 improves glucose homeostasis indirectly via stimulation of nutrient-induced insulin release and by reducing glucagon secretion. Yet the body of literature surrounding GLP-1 physiology reveals an incompletely understood and complex system that includes peripheral and central GLP-1 actions to regulate energy and glucose homeostasis. On the other hand, glucagon is established principally as a counterregulatory hormone, increasing in response to physiological challenges that threaten adequate blood glucose levels and driving glucose production to restore euglycemia. However, there also exists a potential role for glucagon in regulating energy expenditure that has recently been suggested in pharmacological studies. It is also becoming apparent that there is cross-talk between the proglucagon derived-peptides, e.g., GLP-1 inhibits glucagon secretion, and some additive or synergistic pharmacological interaction between GLP-1 and glucagon, e.g., dual glucagon/GLP-1 agonists cause more weight loss than single agonists. In this review, we discuss the physiological functions of both glucagon and GLP-1 by comparing and contrasting how these peptides function, variably in concert and opposition, to regulate glucose and energy homeostasis.
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Affiliation(s)
- Darleen A Sandoval
- Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - David A D'Alessio
- Division of Endocrinology and Metabolism, University of Cincinnati College of Medicine, Cincinnati, Ohio
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Ip W, Shao W, Song Z, Chen Z, Wheeler MB, Jin T. Liver-specific expression of dominant-negative transcription factor 7-like 2 causes progressive impairment in glucose homeostasis. Diabetes 2015; 64:1923-32. [PMID: 25576056 DOI: 10.2337/db14-1329] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/01/2015] [Indexed: 11/13/2022]
Abstract
Investigations on the metabolic role of the Wnt signaling pathway and hepatic transcription factor 7-like 2 (TCF7L2) have generated opposing views. While some studies demonstrated a repressive effect of TCF7L2 on hepatic gluconeogenesis, a recent study using liver-specific Tcf7l2(-/-) mice suggested the opposite. As a consequence of redundant and bidirectional actions of transcription factor (TCF) molecules and other complexities of the Wnt pathway, knockout of a single Wnt pathway component may not effectively reveal a complete metabolic picture of this pathway. To address this, we generated the liver-specific dominant-negative (DN) TCF7L2 (TCF7L2DN) transgenic mouse model LTCFDN. These mice exhibited progressive impairment in response to pyruvate challenge. Importantly, LTCFDN hepatocytes displayed elevated gluconeogenic gene expression, gluconeogenesis, and loss of Wnt-3a-mediated repression of gluconeogenesis. In C57BL/6 hepatocytes, adenovirus-mediated expression of TCF7L2DN, but not wild-type TCF7L2, increased gluconeogenesis and gluconeogenic gene expression. Our further mechanistic exploration suggests that TCF7L2DN-mediated inhibition of Wnt signaling causes preferential interaction of β-catenin (β-cat) with FoxO1 and increased binding of β-cat/FoxO1 to the Pck1 FoxO binding site, resulting in the stimulation of Pck1 expression and increased gluconeogenesis. Together, our results using TCF7L2DN as a unique tool revealed that the Wnt signaling pathway and its effector β-cat/TCF serve a beneficial role in suppressing hepatic gluconeogenesis.
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Affiliation(s)
- Wilfred Ip
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Weijuan Shao
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Zhuolun Song
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Zonglan Chen
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Michael B Wheeler
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Tianru Jin
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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Yao DD, Yang L, Wang Y, Liu C, Wei YJ, Jia XB, Yin W, Shu L. Geniposide promotes beta-cell regeneration and survival through regulating β-catenin/TCF7L2 pathway. Cell Death Dis 2015; 6:e1746. [PMID: 25950476 PMCID: PMC4669687 DOI: 10.1038/cddis.2015.107] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 01/09/2023]
Abstract
T-cell factor 7-like 2 (TCF7L2) is an important transcription factor of Wnt/β-catenin signaling, which has critical roles in β-cell survival and regeneration. In preliminary screening assay, we found geniposide, a naturally occurring compound, was able to increase TCF7L2 mRNA level in Min6 cells. Here we aimed to investigate the role of geniposide in β-cell and underlying mechanism involved. Geniposide was found to promote β-cell survival by increasing β-cell proliferation and decreasing β-cell apoptosis in cultured mouse islets after challenge with diabetic stimuli. Geniposide protected β-cell through activating Wnt signaling, enhanced expressions of TCF7L2 and GLP-1R, activated AKT, inhibited GSK3β activity, and promoted β-catenin nuclear translocation. The protective effect of geniposide was remarkably suppressed by siRNAs against β-catenin, or by ICG001 (β-catenin/TCF-mediated transcription inhibitor). Moreover, geniposide promoted β-cell regeneration in vivo to normalize blood glucose in high-fat diet and db/db mice. Increased β-cell proliferation was observed in pancreatic sections of geniposide-treated diabetic mice. Most importantly, geniposide triggered small islet-like cell clusters formation as a result of β-cell neogenesis from ductal epithelium, which was well correlated with the increase in TCF7L2 expression. In exocrine cells isolated from mouse pancreas, geniposide could induce duct cell differentiation through upregulating TCF7L2 expression and activating JAK2/STAT3 pathway. Taken together, we identified a novel role of geniposide in promoting β-cell survival and regeneration by mechanisms involving the activation of β-catenin/TCF7L2 signaling. Our finding highlights the potential value of geniposide as a possible treatment for type 2 diabetes.
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Affiliation(s)
- D D Yao
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Province Academy of Chinese Medicine, Nanjing, China
| | - L Yang
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Province Academy of Chinese Medicine, Nanjing, China
| | - Y Wang
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - C Liu
- Department of Endocrinology, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Y J Wei
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Province Academy of Chinese Medicine, Nanjing, China
| | - X B Jia
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Province Academy of Chinese Medicine, Nanjing, China
| | - W Yin
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China
| | - L Shu
- Key Laboratory of New Drug Delivery System of Chinese Materia Medica, Jiangsu Province Academy of Chinese Medicine, Nanjing, China
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Migliorini A, Lickert H. Beyond association: A functional role for Tcf7l2 in β-cell development. Mol Metab 2015; 4:365-6. [PMID: 25973384 PMCID: PMC4421078 DOI: 10.1016/j.molmet.2015.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 03/07/2015] [Indexed: 01/24/2023] Open
Affiliation(s)
- Adriana Migliorini
- Institute of Stem Cell Research (ISF), Helmholtz Center, Munich, Germany ; Institute of Diabetes and Regeneration (IDR), Helmholtz Center, Munich, Germany
| | - Heiko Lickert
- Institute of Stem Cell Research (ISF), Helmholtz Center, Munich, Germany ; Institute of Diabetes and Regeneration (IDR), Helmholtz Center, Munich, Germany ; Technical University Munich (TUM), Germany ; German Center for Diabetes Research (DZD), Germany ; Helmholtz Alliance ICEMED - Imaging and Curing Environmental Metabolic Diseases.(ICEMED), Helmholtz Zentrum München, Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
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Acute Wnt pathway activation positively regulates leptin gene expression in mature adipocytes. Cell Signal 2015; 27:587-97. [DOI: 10.1016/j.cellsig.2014.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 12/22/2014] [Indexed: 01/11/2023]
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Shao W, Xiong X, Ip W, Xu F, Song Z, Zeng K, Hernandez M, Liang T, Weng J, Gaisano H, Nostro MC, Jin T. The expression of dominant negative TCF7L2 in pancreatic beta cells during the embryonic stage causes impaired glucose homeostasis. Mol Metab 2015; 4:344-52. [PMID: 25830097 PMCID: PMC4354927 DOI: 10.1016/j.molmet.2015.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 01/21/2015] [Accepted: 01/24/2015] [Indexed: 12/13/2022] Open
Abstract
Objective Disruption of TCF7L2 in mouse pancreatic β-cells has generated different outcomes in several investigations. Here we aim to clarify role of β-cell TCF7L2 and Wnt signaling using a functional-knockdown approach. Methods Adenovirus-mediated dominant negative TCF7L2 (TCF7L2DN) expression was conducted in Ins-1 cells. The fusion gene in which TCF7L2DN expression is driven by PTRE3G was utilized to generate the transgenic mouse line TCF7L2DNTet. The double transgenic line was created by mating TCF7L2DNTet with Ins2-rtTA, designated as βTCFDN. β-cell specific TCF7L2DN expression was induced in βTCFDN by doxycycline feeding. Results TCF7L2DN expression in Ins-1 cells reduced GSIS, cell proliferation and expression of a battery of genes including incretin receptors and β-cell transcription factors. Inducing TCF7L2DN expression in βTCFDN during adulthood or immediately after weaning generated no or very modest metabolic defect, while its expression during embryonic development by doxycycline feeding in pregnant mothers resulted in significant glucose intolerance associated with altered β-cell gene expression and reduced β-cell mass. Conclusions Our observations support a cell autonomous role for TCF7L2 in pancreatic β-cells suggested by most, though not all, investigations. βTCFDN is a novel model for further exploring the role of TCF7L2 in β-cell genesis and metabolic homeostasis.
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Affiliation(s)
- Weijuan Shao
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
| | - Xiaoquan Xiong
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
| | - Wilfred Ip
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 2J7, Canada
| | - Fenghao Xu
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
| | - Zhuolun Song
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
| | - Kejing Zeng
- Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Marcela Hernandez
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, ON, M5G 2C4, Canada
| | - Tao Liang
- Department of Physiology, University of Toronto, Medical Sciences Building, Room 7368, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Jianping Weng
- Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Herbert Gaisano
- Department of Physiology, University of Toronto, Medical Sciences Building, Room 7368, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - M. Cristina Nostro
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, ON, M5G 2C4, Canada
- Department of Physiology, University of Toronto, Medical Sciences Building, Room 7368, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Tianru Jin
- Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 2J7, Canada
- McEwen Centre for Regenerative Medicine, University Health Network, Toronto, ON, M5G 2C4, Canada
- Corresponding author. Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, M5G 2C4, Canada.
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Rutter GA, Hodson DJ. Beta cell connectivity in pancreatic islets: a type 2 diabetes target? Cell Mol Life Sci 2015; 72:453-467. [PMID: 25323131 PMCID: PMC11113448 DOI: 10.1007/s00018-014-1755-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/30/2014] [Accepted: 10/01/2014] [Indexed: 12/12/2022]
Abstract
Beta cell connectivity describes the phenomenon whereby the islet context improves insulin secretion by providing a three-dimensional platform for intercellular signaling processes. Thus, the precise flow of information through homotypically interconnected beta cells leads to the large-scale organization of hormone release activities, influencing cell responses to glucose and other secretagogues. Although a phenomenon whose importance has arguably been underappreciated in islet biology until recently, a growing number of studies suggest that such cell-cell communication is a fundamental property of this micro-organ. Hence, connectivity may plausibly be targeted by both environmental and genetic factors in type 2 diabetes mellitus (T2DM) to perturb normal beta cell function and insulin release. Here, we review the mechanisms that contribute to beta cell connectivity, discuss how these may fail during T2DM, and examine approaches to restore insulin secretion by boosting cell communication.
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Affiliation(s)
- Guy A Rutter
- Section of Cell Biology, Department of Medicine, Imperial College London, Imperial Centre for Translational and Experimental Medicine, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
| | - David J Hodson
- Section of Cell Biology, Department of Medicine, Imperial College London, Imperial Centre for Translational and Experimental Medicine, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
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