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Zacarías-Fluck MF, Soucek L, Whitfield JR. MYC: there is more to it than cancer. Front Cell Dev Biol 2024; 12:1342872. [PMID: 38510176 PMCID: PMC10952043 DOI: 10.3389/fcell.2024.1342872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024] Open
Abstract
MYC is a pleiotropic transcription factor involved in multiple cellular processes. While its mechanism of action and targets are not completely elucidated, it has a fundamental role in cellular proliferation, differentiation, metabolism, ribogenesis, and bone and vascular development. Over 4 decades of research and some 10,000 publications linking it to tumorigenesis (by searching PubMed for "MYC oncogene") have led to MYC becoming a most-wanted target for the treatment of cancer, where many of MYC's physiological functions become co-opted for tumour initiation and maintenance. In this context, an abundance of reviews describes strategies for potentially targeting MYC in the oncology field. However, its multiple roles in different aspects of cellular biology suggest that it may also play a role in many additional diseases, and other publications are indeed linking MYC to pathologies beyond cancer. Here, we review these physiological functions and the current literature linking MYC to non-oncological diseases. The intense efforts towards developing MYC inhibitors as a cancer therapy will potentially have huge implications for the treatment of other diseases. In addition, with a complementary approach, we discuss some diseases and conditions where MYC appears to play a protective role and hence its increased expression or activation could be therapeutic.
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Affiliation(s)
- Mariano F. Zacarías-Fluck
- Models of Cancer Therapies Laboratory, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Laura Soucek
- Models of Cancer Therapies Laboratory, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, Barcelona, Spain
- Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Bellaterra, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Peptomyc S.L., Barcelona, Spain
| | - Jonathan R. Whitfield
- Models of Cancer Therapies Laboratory, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, Barcelona, Spain
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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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3
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Song Y, He C, Jiang Y, Yang M, Xu Z, Yuan L, Zhang W, Xu Y. Bulk and single-cell transcriptome analyses of islet tissue unravel gene signatures associated with pyroptosis and immune infiltration in type 2 diabetes. Front Endocrinol (Lausanne) 2023; 14:1132194. [PMID: 36967805 PMCID: PMC10034023 DOI: 10.3389/fendo.2023.1132194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
INTRODUCTION Type 2 diabetes (T2D) is a common chronic heterogeneous metabolic disorder. However, the roles of pyroptosis and infiltrating immune cells in islet dysfunction of patients with T2D have yet to be explored. In this study, we aimed to explore potential crucial genes and pathways associated with pyroptosis and immune infiltration in T2D. METHODS To achieve this, we performed a conjoint analysis of three bulk RNA-seq datasets of islets to identify T2D-related differentially expressed genes (DEGs). After grouping the islet samples according to their ESTIMATE immune scores, we identified immune- and T2D-related DEGs. A clinical prediction model based on pyroptosis-related genes for T2D was constructed. Weighted gene co-expression network analysis was performed to identify genes positively correlated with pyroptosis-related pathways. A protein-protein interaction network was established to identify pyroptosis-related hub genes. We constructed miRNA and transcriptional networks based on the pyroptosis-related hub genes and performed functional analyses. Single-cell RNA-seq (scRNA-seq) was conducted using the GSE153885 dataset. Dimensionality was reduced using principal component analysis and t-distributed statistical neighbor embedding, and cells were clustered using Seurat. Different cell types were subjected to differential gene expression analysis and gene set enrichment analysis (GSEA). Cell-cell communication and pseudotime trajectory analyses were conducted using the samples from patients with T2D. RESULTS We identified 17 pyroptosis-related hub genes. We determined the abundance of 13 immune cell types in the merged matrix and found that these cell types were correlated with the 17 pyroptosis-related hub genes. Analysis of the scRNA-seq dataset of 1892 islet samples from patients with T2D and controls revealed 11 clusters. INS and IAPP were determined to be pyroptosis-related and candidate hub genes among the 11 clusters. GSEA of the 11 clusters demonstrated that the myc, G2M checkpoint, and E2F pathways were significantly upregulated in clusters with several differentially enriched pathways. DISCUSSION This study elucidates the gene signatures associated with pyroptosis and immune infiltration in T2D and provides a critical resource for understanding of islet dysfunction and T2D pathogenesis.
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Affiliation(s)
- Yaxian Song
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Chen He
- Department of Geriatric Medicine, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yan Jiang
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Mengshi Yang
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Zhao Xu
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Lingyan Yuan
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Wenhua Zhang
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yushan Xu
- Department of Endocrinology, Yunnan Province Clinical Medical Center for Endocrine and Metabolic Disease, The First Affiliated Hospital of Kunming Medical University, Kunming, China
- *Correspondence: Yushan Xu,
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4
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Roles and action mechanisms of WNT4 in cell differentiation and human diseases: a review. Cell Death Discov 2021; 7:287. [PMID: 34642299 PMCID: PMC8511224 DOI: 10.1038/s41420-021-00668-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/24/2021] [Accepted: 09/20/2021] [Indexed: 02/07/2023] Open
Abstract
WNT family member 4 (WNT4), which belongs to the conserved WNT protein family, plays an important role in the development and differentiation of many cell types during the embryonic development and adult homeostasis. Increasing evidence has shown that WNT4 is a special ligand that not only activates the β-catenin independent pathway but also acts on β-catenin signaling based on different cellular processes. This article is a summary of the current knowledge about the expression, regulation, and function of WNT4 ligands and their signal pathways in cell differentiation and human disease processes. WNT4 is a promoter in osteogenic differentiation in bone marrow stromal cells (BMSCs) by participating in bone homeostasis regulation in osteoporotic diseases. Non-canonical WNT4 signaling is necessary for metabolic maturation of pancreatic β-cell. WNT4 is also necessary for decidual cell differentiation and decidualization, which plays an important role in preeclampsia. WNT4 promotes neuronal differentiation of neural stem cell and dendritic cell (DC) into conventional type 1 DC (cDC1). Besides, WNT4 mediates myofibroblast differentiation in the skin, kidney, lung, and liver during scarring or fibrosis. On the negative side, WNT4 is highly expressed in cancer tissues, playing a pro-carcinogenic role in many cancer types. This review provides an overview of the progress in elucidating the role of WNT4 signaling pathway components in cell differentiation in adults, which may provide useful clues for the diagnosis, prevention, and therapy of human diseases.
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Chan JY, Bensellam M, Lin RCY, Liang C, Lee K, Jonas JC, Laybutt DR. Transcriptome analysis of islets from diabetes-resistant and diabetes-prone obese mice reveals novel gene regulatory networks involved in beta-cell compensation and failure. FASEB J 2021; 35:e21608. [PMID: 33977593 DOI: 10.1096/fj.202100009r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 03/23/2021] [Accepted: 04/05/2021] [Indexed: 01/02/2023]
Abstract
The mechanisms underpinning beta-cell compensation for obesity-associated insulin resistance and beta-cell failure in type 2 diabetes remain poorly understood. We used a large-scale strategy to determine the time-dependent transcriptomic changes in islets of diabetes-prone db/db and diabetes-resistant ob/ob mice at 6 and 16 weeks of age. Differentially expressed genes were subjected to cluster, gene ontology, pathway and gene set enrichment analyses. A distinctive gene expression pattern was observed in 16 week db/db islets in comparison to the other groups with alterations in transcriptional regulators of islet cell identity, upregulation of glucose/lipid metabolism, and various stress response genes, and downregulation of specific amino acid transport and metabolism genes. In contrast, ob/ob islets displayed a coordinated downregulation of metabolic and stress response genes at 6 weeks of age, suggestive of a preemptive reconfiguration in these islets to lower the threshold of metabolic activation in response to increased insulin demand thereby preserving beta-cell function and preventing cellular stress. In addition, amino acid transport and metabolism genes were upregulated in ob/ob islets, suggesting an important role of glutamate metabolism in beta-cell compensation. Gene set enrichment analysis of differentially expressed genes identified the enrichment of binding motifs for transcription factors, FOXO4, NFATC1, and MAZ. siRNA-mediated knockdown of these genes in MIN6 cells altered cell death, insulin secretion, and stress gene expression. In conclusion, these data revealed novel gene regulatory networks involved in beta-cell compensation and failure. Preemptive metabolic reconfiguration in diabetes-resistant islets may dampen metabolic activation and cellular stress during obesity.
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Affiliation(s)
- Jeng Yie Chan
- Garvan Institute of Medical Research, Sydney, NSW, Australia.,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Mohammed Bensellam
- Garvan Institute of Medical Research, Sydney, NSW, Australia.,Pôle D'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Ruby C Y Lin
- School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Centre for Infectious Diseases and Microbiology, Westmead Institute for Medical Research, Sydney, NSW, Australia.,Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Cassandra Liang
- Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Kailun Lee
- Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Jean-Christophe Jonas
- Pôle D'endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - D Ross Laybutt
- Garvan Institute of Medical Research, Sydney, NSW, Australia.,School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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6
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Nie X, Wei X, Ma H, Fan L, Chen WD. The complex role of Wnt ligands in type 2 diabetes mellitus and related complications. J Cell Mol Med 2021; 25:6479-6495. [PMID: 34042263 PMCID: PMC8278111 DOI: 10.1111/jcmm.16663] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/02/2021] [Accepted: 05/10/2021] [Indexed: 12/15/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is one of the major chronic diseases, whose prevalence is increasing dramatically worldwide and can lead to a range of serious complications. Wnt ligands (Wnts) and their activating Wnt signalling pathways are closely involved in the regulation of various processes that are important for the occurrence and progression of T2DM and related complications. However, our understanding of their roles in these diseases is quite rudimentary due to the numerous family members of Wnts and conflicting effects via activating the canonical and/or non-canonical Wnt signalling pathways. In this review, we summarize the current findings on the expression pattern and exact role of each human Wnt in T2DM and related complications, including Wnt1, Wnt2, Wnt2b, Wnt3, Wnt3a, Wnt4, Wnt5a, Wnt5b, Wnt6, Wnt7a, Wnt7b, Wnt8a, Wnt8b, Wnt9a, Wnt9b, Wnt10a, Wnt10b, Wnt11 and Wnt16. Moreover, the role of main antagonists (sFRPs and WIF-1) and coreceptor (LRP6) of Wnts in T2DM and related complications and main challenges in designing Wnt-based therapeutic approaches for these diseases are discussed. We hope a deep understanding of the mechanistic links between Wnt signalling pathways and diabetic-related diseases will ultimately result in a better management of these diseases.
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Affiliation(s)
- Xiaobo Nie
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Basic Medical Sciences, People's Hospital of Hebi, Henan University, Kaifeng, China
| | - Xiaoyun Wei
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Basic Medical Sciences, People's Hospital of Hebi, Henan University, Kaifeng, China
| | - Han Ma
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Basic Medical Sciences, People's Hospital of Hebi, Henan University, Kaifeng, China
| | - Lili Fan
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Basic Medical Sciences, People's Hospital of Hebi, Henan University, Kaifeng, China
| | - Wei-Dong Chen
- Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Basic Medical Sciences, People's Hospital of Hebi, Henan University, Kaifeng, China.,Key Laboratory of Molecular Pathology, School of Basic Medical Science, Inner Mongolia Medical University, Hohhot, China
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7
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Zhou AX, Mondal T, Tabish AM, Abadpour S, Ericson E, Smith DM, Knöll R, Scholz H, Kanduri C, Tyrberg B, Althage M. The long noncoding RNA TUNAR modulates Wnt signaling and regulates human β-cell proliferation. Am J Physiol Endocrinol Metab 2021; 320:E846-E857. [PMID: 33682459 DOI: 10.1152/ajpendo.00335.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many long noncoding RNAs (lncRNAs) are enriched in pancreatic islets and several lncRNAs are linked to type 2 diabetes (T2D). Although they have emerged as potential players in β-cell biology and T2D, little is known about their functions and mechanisms in human β-cells. We identified an islet-enriched lncRNA, TUNAR (TCL1 upstream neural differentiation-associated RNA), which was upregulated in β-cells of patients with T2D and promoted human β-cell proliferation via fine-tuning of the Wnt pathway. TUNAR was upregulated following Wnt agonism by a glycogen synthase kinase-3 (GSK3) inhibitor in human β-cells. Reciprocally, TUNAR repressed a Wnt antagonist Dickkopf-related protein 3 (DKK3) and stimulated Wnt pathway signaling. DKK3 was aberrantly expressed in β-cells of patients with T2D and displayed a synchronized regulatory pattern with TUNAR at the single cell level. Mechanistically, DKK3 expression was suppressed by the repressive histone modifier enhancer of zeste homolog 2 (EZH2). TUNAR interacted with EZH2 in β-cells and facilitated EZH2-mediated suppression of DKK3. These findings reveal a novel cell-specific epigenetic mechanism via islet-enriched lncRNA that fine-tunes the Wnt pathway and subsequently human β-cell proliferation.NEW & NOTEWORTHY The discovery that long noncoding RNA TUNAR regulates β-cell proliferation may be important in designing new treatments for diabetes.
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Affiliation(s)
- Alex-Xianghua Zhou
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Tanmoy Mondal
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Ali Mustafa Tabish
- Integrated Cardio Metabolic Centre, Karolinska Institute, Stockholm, Sweden
| | - Shadab Abadpour
- Department of Transplant Medicine, Institute for Surgical Research, Oslo University Hospital, Oslo, Norway
- Hybrid Technology Hub, Centre of Excellence, University of Oslo, Oslo, Norway
| | - Elke Ericson
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - David M Smith
- Emerging Innovations Unit, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Ralph Knöll
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Integrated Cardio Metabolic Centre, Karolinska Institute, Stockholm, Sweden
| | - Hanne Scholz
- Department of Transplant Medicine, Institute for Surgical Research, Oslo University Hospital, Oslo, Norway
| | - Chandrasekhar Kanduri
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Björn Tyrberg
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Magnus Althage
- Research and Early Development Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
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8
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Role of Wnt signaling pathways in type 2 diabetes mellitus. Mol Cell Biochem 2021; 476:2219-2232. [PMID: 33566231 DOI: 10.1007/s11010-021-04086-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/27/2021] [Indexed: 01/03/2023]
Abstract
Type 2 diabetes mellitus (T2DM) has become a major global public health issue in the twenty-first century and its incidence has increased each year. Wnt signaling pathways are a set of multi-downstream signaling pathways activated by the binding of Wnt ligands to membrane protein receptors. Wnt signaling pathways regulate protein expression and play important roles in protecting the body's normal physiological metabolism. This review describes Wnt signaling pathways, and then aims to reveal how Wnt signaling pathways participate in the occurrence and development of T2DM. We found that Wnt/c-Jun N-terminal kinase signaling was closely associated with insulin resistance, inflammatory response, and pancreatic β-cell and endothelial dysfunction. β-catenin/transcription factor 7-like 2 (TCF7L2)-mediated and calcineurin/nuclear factor of activated T cells-mediated target genes were involved in insulin synthesis and secretion, insulin degradation, pancreatic β-cell growth and regeneration, and functional application of pancreatic β-cells. In addition, polymorphisms in the TCF7L2 gene could increase risk of T2DM according to previous and the most current results, and the T allele of its variants was a more adverse factor for abnormal pancreatic β-cell function and impaired glucose tolerance in patients with T2DM. These findings indicate a strong correlation between Wnt signaling pathways and T2DM, particularly in terms of pancreatic islet dysfunction and insulin resistance, and new therapeutic targets for T2DM may be identified.
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9
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Azarova I, Klyosova E, Lazarenko V, Konoplya A, Polonikov A. Genetic variants in glutamate cysteine ligase confer protection against type 2 diabetes. Mol Biol Rep 2020; 47:5793-5805. [PMID: 32715377 DOI: 10.1007/s11033-020-05647-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/08/2020] [Indexed: 12/13/2022]
Abstract
Oxidative stress contributes to the pathogenesis of type 2 diabetes (T2D). This study investigated whether single nucleotide polymorphisms (SNPs) at genes encoding glutamate cysteine ligase catalytic (rs12524494, rs17883901, rs606548, rs636933, rs648595, rs761142 at GCLC) and modifier (rs2301022, rs3827715, rs7517826, rs41303970 at GCLM) subunits are associated with susceptibility to type 2 diabetes. 2096 unrelated Russian subjects were enrolled for the study. Genotyping was done with the use of the MassArray System. Plasma levels of reactive oxygen species (ROS) and glutathione in the study subjects were analyzed by fluorometric and colorimetric assays, respectively.The present study found, for the first time, an association of SNP rs41303970 in the GCLM gene with a decreased risk of T2D (P = 0.034, Q = 0.17). Minor alleles such as rs12524494-G GCLC gene (P = 0.026, Q = 0.17) and rs3827715-C GCLM gene (P = 0.03, Q = 0.17) were also associated with reduced risk for T2D. Protective effects of variant alleles such as rs12524494-G at GCLC (P = 0.02, Q = 0.26) and rs41303970-A GCLM (P = 0.013, Q = 0.25) against the risk of T2D were seen solely in nonsmokers. As compared with healthy controls, diabetic patients had markedly increased levels of ROS and decreased levels of total GSH in plasma. Interestingly, fasting blood glucose level positively correlated with oxidized glutathione concentration (rs = 0.208, P = 0.01). Three SNPs rs17883901, rs636933, rs648595 at GCLC and one rs2301022 at GCLM were associated with decreased levels of ROS, while SNPs rs7517826, rs41303970 at GCLM were associated with increased levels of total GSH in plasma. Single nucleotide polymorphisms in genes encoding glutamate cysteine ligase subunits confer protection against type 2 diabetes and their effects are mediated through increased levels of glutathione.
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Affiliation(s)
- Iuliia Azarova
- Department of Biological Chemistry, Kursk State Medical University, 3 Karl Marx Street, Kursk, Russian Federation, 305041. .,Laboratory of Biochemical Genetics and Metabolomics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya St., Kursk, Russian Federation, 305041.
| | - Elena Klyosova
- Laboratory of Biochemical Genetics and Metabolomics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya St., Kursk, Russian Federation, 305041
| | - Victor Lazarenko
- Department of Surgical Diseases of Postgraduate Faculty, Kursk State Medical University, 3 Karl Marx Street, Kursk, Russian Federation, 305041
| | - Alexander Konoplya
- Department of Biological Chemistry, Kursk State Medical University, 3 Karl Marx Street, Kursk, Russian Federation, 305041
| | - Alexey Polonikov
- Department of Biology, Medical Genetics and Ecology, Kursk State Medical University, 3 Karl Marx Street, Kursk, Russian Federation, 305041.,Laboratory of Statistical Genetics and Bioinformatics, Research Institute for Genetic and Molecular Epidemiology, Kursk State Medical University, 18 Yamskaya St., Kursk, Russian Federation, 305041
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10
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Sasidharan Nair V, M Toor S, Z Taha R, Ahmed AA, Kurer MA, Murshed K, Soofi ME, Ouararhni K, M. Alajez N, Abu Nada M, Elkord E. Transcriptomic Profiling of Tumor-Infiltrating CD4 +TIM-3 + T Cells Reveals Their Suppressive, Exhausted, and Metastatic Characteristics in Colorectal Cancer Patients. Vaccines (Basel) 2020; 8:vaccines8010071. [PMID: 32041340 PMCID: PMC7157206 DOI: 10.3390/vaccines8010071] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/04/2020] [Accepted: 02/04/2020] [Indexed: 12/29/2022] Open
Abstract
T cell immunoglobulin mucin-3 (TIM-3) is an immune checkpoint identified as one of the key players in regulating T-cell responses. Studies have shown that TIM-3 is upregulated in the tumor microenvironment (TME). However, the precise role of TIM-3 in colorectal cancer (CRC) TME is yet to be elucidated. We performed phenotypic and molecular characterization of TIM-3+ T cells in the TME and circulation of CRC patients by analyzing tumor tissues (TT, TILs), normal tissues (NT, NILs), and peripheral blood mononuclear cells (PBMC). TIM-3 was upregulated on both CD4+ and CD3+CD4− (CD8+) TILs. CD4+TIM-3+ TILs expressed higher levels of T regulatory cell (Tregs)-signature genes, including FoxP3 and Helios, compared with their TIM-3− counterparts. Transcriptomic and ingenuity pathway analyses showed that TIM-3 potentially activates inflammatory and tumor metastatic pathways. Moreover, NF-κB-mediated transcription factors were upregulated in CD4+TIM-3+ TILs, which could favor proliferation/invasion and induce inflammatory and T-cell exhaustion pathways. In addition, we found that CD4+TIM-3+ TILs potentially support tumor invasion and metastasis, compared with conventional CD4+CD25+ Tregs in the CRC TME. However, functional studies are warranted to support these findings. In conclusion, this study discloses some of the functional pathways of TIM-3+ TILs, which could improve their targeting in more specific therapeutic approaches in CRC patients.
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Affiliation(s)
- Varun Sasidharan Nair
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
| | - Salman M Toor
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
| | - Rowaida Z Taha
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
| | - Ayman A Ahmed
- Department of Surgery, Hamad Medical Corporation, P.O. Box 34110, Doha, Qatar; (A.A.A.); (M.A.K.); (M.A.N.)
| | - Mohamed A Kurer
- Department of Surgery, Hamad Medical Corporation, P.O. Box 34110, Doha, Qatar; (A.A.A.); (M.A.K.); (M.A.N.)
| | - Khaled Murshed
- Department of Pathology, Hamad Medical Corporation, P.O. Box 34110, Doha, Qatar; (K.M.); (M.E.S.)
| | - Madiha E Soofi
- Department of Pathology, Hamad Medical Corporation, P.O. Box 34110, Doha, Qatar; (K.M.); (M.E.S.)
| | - Khalid Ouararhni
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
| | - Nehad M. Alajez
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
| | - Mohamed Abu Nada
- Department of Surgery, Hamad Medical Corporation, P.O. Box 34110, Doha, Qatar; (A.A.A.); (M.A.K.); (M.A.N.)
| | - Eyad Elkord
- Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), P.O. Box 34110, Doha, Qatar; (V.S.N.); (S.M.T.); (R.Z.T.); (K.O.); (N.M.A.)
- Biomedical Research Center, School of Science, Engineering and Environment, University of Salford, Manchester M5 4WT, UK
- Correspondence: or ; Tel.: +974-4454-2367; Fax: +974-4454-1770
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Zhu L, Xiang J, Wang Q, Wang A, Li C, Tian G, Zhang H, Chen S. Revealing the Interactions Between Diabetes, Diabetes-Related Diseases, and Cancers Based on the Network Connectivity of Their Related Genes. Front Genet 2020; 11:617136. [PMID: 33381155 PMCID: PMC7767993 DOI: 10.3389/fgene.2020.617136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/18/2020] [Indexed: 11/25/2022] Open
Abstract
Diabetes-related diseases (DRDs), especially cancers pose a big threat to public health. Although people have explored pathological pathways of a few common DRDs, there is a lack of systematic studies on important biological processes (BPs) connecting diabetes and its related diseases/cancers. We have proposed and compared 10 protein-protein interaction (PPI)-based computational methods to study the connections between diabetes and 254 diseases, among which a method called DIconnectivity_eDMN performs the best in the sense that it infers a disease rank (according to its relation with diabetes) most consistent with that by literature mining. DIconnectivity_eDMN takes diabetes-related genes, other disease-related genes, a PPI network, and genes in BPs as input. It first maps genes in a BP into the PPI network to construct a BP-related subnetwork, which is expanded (in the whole PPI network) by a random walk with restart (RWR) process to generate a so-called expanded modularized network (eMN). Since the numbers of known disease genes are not high, an RWR process is also performed to generate an expanded disease-related gene list. For each eMN and disease, the expanded diabetes-related genes and disease-related genes are mapped onto the eMN. The association between diabetes and the disease is measured by the reachability of their genes on all eMNs, in which the reachability is estimated by a method similar to the Kolmogorov-Smirnov (KS) test. DIconnectivity_eDMN achieves an area under receiver operating characteristic curve (AUC) of 0.71 for predicting both Type 1 DRDs and Type 2 DRDs. In addition, DIconnectivity_eDMN reveals important BPs connecting diabetes and DRDs. For example, "respiratory system development" and "regulation of mRNA metabolic process" are critical in associating Type 1 diabetes (T1D) and many Type 1 DRDs. It is also found that the average proportion of diabetes-related genes interacting with DRDs is higher than that of non-DRDs.
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Affiliation(s)
- Lijuan Zhu
- College of Mathematics and Computer Science, Zhejiang Normal University, Jinhua, China
| | - Ju Xiang
- Neuroscience Research Center, Department of Basic Medical Sciences, Changsha Medical University, Changsha, China
- School of Computer Science and Engineering, Central South University, Changsha, China
| | - Qiuling Wang
- Department of Endocrinology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Ailan Wang
- Geneis Beijing Co., Ltd., Beijing, China
| | - Chao Li
- Geneis Beijing Co., Ltd., Beijing, China
| | - Geng Tian
- Geneis Beijing Co., Ltd., Beijing, China
- Qingdao Geneis Institute of Big Data Mining and Precision Medicine, Qingdao, China
| | - Huajun Zhang
- College of Mathematics and Computer Science, Zhejiang Normal University, Jinhua, China
- *Correspondence: Huajun Zhang,
| | - Size Chen
- Department of Oncology, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangdong Provincial Engineering Research Center for Esophageal Cancer Precision Treatment, Guangzhou, China
- Size Chen,
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12
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Kurita Y, Ohki T, Soejima E, Yuan X, Kakino S, Wada N, Hashinaga T, Nakayama H, Tani J, Tajiri Y, Hiromatsu Y, Yamada K, Nomura M. A High-Fat/High-Sucrose Diet Induces WNT4 Expression in Mouse Pancreatic β-cells. Kurume Med J 2019; 65:55-62. [PMID: 30853690 DOI: 10.2739/kurumemedj.ms652008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Aims/Introduction: Several lines of evidence suggest that dysregulation of the WNT signaling pathway is involved in the pathogenesis of type 2 diabetes. This study was performed to elucidate the effects of a high-fat/high-sucrose (HF/HS) diet on pancreatic islet functions in relation to modulation of WNT ligand expression in β-cells. MATERIALS AND METHODS Mice were fed either standard mouse chow or a HF/HS diet from 8 weeks of age. At 20 weeks of age, intraperitoneal glucose tolerance tests were performed in both groups of mice, followed by euthanasia and isolation of pancreatic islets. WNT-related gene expression in islets and MIN6 cells was measured by quantitative real-time RT-PCR. To explore the direct effects of WNT signals on pancreatic β-cells, MIN6 cells were exposed to recombinant mouse WNT4 protein (rmWNT4) for 48 h, and glucose-induced insulin secretion was measured. Furthermore, Wnt4 siRNAs were transfected into MIN6 cells, and cell viability and insulin secretion were measured in control and Wnt4 siRNA-transfected MIN6 cells. RESULTS Mice fed the HF/HS diet were heavier and their plasma glucose and insulin levels were higher compared with mice fed standard chow. Wnt4, Wnt5b, Ror1, and Ror2 expression was upregulated, while Fzd4, Fzd5, Fzd6, Lrp5, and Lrp6 expression was downregulated in the islets of mice fed the HF/HS diet. Wnt4 was the most abundantly expressed WNT ligand in β-cells, and its expression was increased by the HF/HS diet. Although exposure to recombinant mouse WNT4 protein for 48 h did not alter glucose-induced insulin secretion, it was significantly reduced by knockdown of Wnt4 in MIN6 cells. CONCLUSIONS We demonstrated that the HF/HS diet-induced increase of WNT4 signaling in β-cells is involved in augmentation of glucose-induced insulin secretion and impaired β-cell proliferation. These results strongly indicate an essential role of WNT4 in the regulation of β-cell functions in mouse pancreatic islets.
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Affiliation(s)
- Yayoi Kurita
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Tsuyoshi Ohki
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Eri Soejima
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Xiaohong Yuan
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Satomi Kakino
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Nobuhiko Wada
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Toshihiko Hashinaga
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Hitomi Nakayama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Junichi Tani
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Yuji Tajiri
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | - Yuji Hiromatsu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
| | | | - Masatoshi Nomura
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine
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13
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Pujar MK, Vastrad B, Vastrad C. Integrative Analyses of Genes Associated with Subcutaneous Insulin Resistance. Biomolecules 2019; 9:biom9020037. [PMID: 30678306 PMCID: PMC6406848 DOI: 10.3390/biom9020037] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/16/2019] [Indexed: 02/07/2023] Open
Abstract
Insulin resistance is present in the majority of patients with non-insulin-dependent diabetes mellitus (NIDDM) and obesity. In this study, we aimed to investigate the key genes and potential molecular mechanism in insulin resistance. Expression profiles of the genes were extracted from the Gene Expression Omnibus (GEO) database. Pathway and Gene Ontology (GO) enrichment analyses were conducted at Enrichr. The protein–protein interaction (PPI) network was settled and analyzed using the Search Tool for the Retrieval of Interacting Genes (STRING) database constructed by Cytoscape software. Modules were extracted and identified by the PEWCC1 plugin. The microRNAs (miRNAs) and transcription factors (TFs) which control the expression of differentially expressed genes (DEGs) were analyzed using the NetworkAnalyst algorithm. A database (GSE73108) was downloaded from the GEO databases. Our results identified 873 DEGs (435 up-regulated and 438 down-regulated) genetically associated with insulin resistance. The pathways which were enriched were pathways in complement and coagulation cascades and complement activation for up-regulated DEGs, while biosynthesis of amino acids and the Notch signaling pathway were among the down-regulated DEGs. Showing GO enrichment were cardiac muscle cell–cardiac muscle cell adhesion and microvillus membrane for up-regulated DEGs and negative regulation of osteoblast differentiation and dendrites for down-regulated DEGs. Subsequently, myosin VB (MYO5B), discs, large homolog 2(DLG2), axin 2 (AXIN2), protein tyrosine kinase 7 (PTK7), Notch homolog 1 (NOTCH1), androgen receptor (AR), cyclin D1 (CCND1) and Rho family GTPase 3 (RND3) were diagnosed as the top hub genes in the up- and down-regulated PPI network and modules. In addition, GATA binding protein 6 (GATA6), ectonucleotide pyrophosphatase/phosphodiesterase 5 (ENPP5), cyclin D1 (CCND1) and tubulin, beta 2A (TUBB2A) were diagnosed as the top hub genes in the up- and down-regulated target gene–miRNA network, while tubulin, beta 2A (TUBB2A), olfactomedin-like 1 (OLFML1), prostate adrogen-regulated mucin-like protein 1 (PARM1) and aldehyde dehydrogenase 4 family, member A1 (ALDH4A1)were diagnosed as the top hub genes in the up- and down-regulated target gene–TF network. The current study based on the GEO database provides a novel understanding regarding the mechanism of insulin resistance and may provide novel therapeutic targets.
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Affiliation(s)
- Manoj Kumar Pujar
- Department of Medicine, Pooja Hospital, Davangere577002, Karnataka, India.
| | - Basavaraj Vastrad
- Department of Pharmaceutics, SET`S College of Pharmacy, Dharwad 580002, Karnataka, India.
| | - Chanabasayya Vastrad
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad 580001, Karanataka, India.
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14
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Huang QY, Lai XN, Qian XL, Lv LC, Li J, Duan J, Xiao XH, Xiong LX. Cdc42: A Novel Regulator of Insulin Secretion and Diabetes-Associated Diseases. Int J Mol Sci 2019; 20:ijms20010179. [PMID: 30621321 PMCID: PMC6337499 DOI: 10.3390/ijms20010179] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 02/07/2023] Open
Abstract
Cdc42, a member of the Rho GTPases family, is involved in the regulation of several cellular functions including cell cycle progression, survival, transcription, actin cytoskeleton organization and membrane trafficking. Diabetes is a chronic and metabolic disease, characterized as glycometabolism disorder induced by insulin deficiency related to β cell dysfunction and peripheral insulin resistance (IR). Diabetes could cause many complications including diabetic nephropathy (DN), diabetic retinopathy and diabetic foot. Furthermore, hyperglycemia can promote tumor progression and increase the risk of malignant cancers. In this review, we summarized the regulation of Cdc42 in insulin secretion and diabetes-associated diseases. Organized researches indicate that Cdc42 is a crucial member during the progression of diabetes, and Cdc42 not only participates in the process of insulin synthesis but also regulates the insulin granule mobilization and cell membrane exocytosis via activating a series of downstream factors. Besides, several studies have demonstrated Cdc42 as participating in the pathogenesis of IR and DN and even contributing to promote cancer cell proliferation, survival, invasion, migration, and metastasis under hyperglycemia. Through the current review, we hope to cast light on the mechanism of Cdc42 in diabetes and associated diseases and provide new ideas for clinical diagnosis, treatment, and prevention.
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Affiliation(s)
- Qi-Yuan Huang
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xing-Ning Lai
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xian-Ling Qian
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Lin-Chen Lv
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Jun Li
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Jing Duan
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xing-Hua Xiao
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Li-Xia Xiong
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
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15
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The role of adherens junction proteins in the regulation of insulin secretion. Biosci Rep 2018; 38:BSR20170989. [PMID: 29459424 PMCID: PMC5861323 DOI: 10.1042/bsr20170989] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/17/2018] [Accepted: 02/19/2018] [Indexed: 12/16/2022] Open
Abstract
In healthy individuals, any rise in blood glucose levels is rapidly countered by the release of insulin from the β-cells of the pancreas which in turn promotes the uptake and storage of the glucose in peripheral tissues. The β-cells possess exquisite mechanisms regulating the secretion of insulin to ensure that the correct amount of insulin is released. These mechanisms involve tight control of the movement of insulin containing secretory vesicles within the β-cells, initially preventing most vesicles being able to move to the plasma membrane. Elevated glucose levels trigger an influx of Ca2+ that allows fusion of the small number of insulin containing vesicles that are pre-docked at the plasma membrane but glucose also stimulates processes that allow other insulin containing vesicles located further in the cell to move to and fuse with the plasma membrane. The mechanisms controlling these processes are complex and not fully understood but it is clear that the interaction of the β-cells with other β-cells in the islets is very important for their ability to develop the appropriate machinery for proper regulation of insulin secretion. Emerging evidence indicates one factor that is key for this is the formation of homotypic cadherin mediated adherens junctions between β-cells. Here, we review the evidence for this and discuss the mechanisms by which these adherens junctions might regulate insulin vesicle trafficking as well as the implications this has for understanding the dysregulation of insulin secretion seen in pathogenic states.
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16
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Li Q, Guo D, Yang H, Ye Z, Huang J, Shu Y. Metabolic Response to Olanzapine in Healthy Chinese Subjects with rs7093146 Polymorphism in Transcription Factor 7-like 2 Gene (TCF7L2): A Prospective Study. Basic Clin Pharmacol Toxicol 2017; 120:601-609. [PMID: 27983772 DOI: 10.1111/bcpt.12727] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/02/2016] [Indexed: 12/20/2022]
Abstract
Olanzapine is a widely used atypical antipsychotic with significant weight gain and other metabolic side effects. The locus of the transcription factor 7-like 2 (TCF7L2) gene is strongly associated with type 2 diabetes (T2D). The goal of this study was to determine whether polymorphic TCF7L2 is involved in the susceptibility to the metabolic changes associated with the atypical antipsychotic agents (AAPs). In this study, a parallel clinical study with 3-day consecutive administration of olanzapine (10 mg/day) was conducted in 17 healthy subjects with a genotype of TCF7L2 rs7903146 CC (N = 10) or CT (N = 7). Olanzapine caused rapid metabolic changes including body-weight gain, increased triglycerides level and reduced HDL-cholesterol level in the healthy subjects. rs7093146 T carriers (CT) were found to have greater AUC0-2 hr of insulin during OGTT compared to those (CC) bearing only reference alleles before and after olanzapine treatment. However, the triglyceride level in the subjects with the CT genotype was found to be significantly lower than that in the subjects with CC genotype. Moreover, a significant interaction between the effect by genotype and that by olanzapine treatment on triglyceride level was identified. Acute olanzapine treatment also significantly caused total protein, albumin and haemoglobin decrease and uric acid increase in the healthy subjects. In conclusion, even acute olanzapine treatment induces significant and rapid metabolic changes, and TCF7L2 polymorphism is a genetic risk factor of olanzapine-associated metabolic side effects.
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Affiliation(s)
- Qing Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Hunan, China
| | - Dong Guo
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Hong Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Zhi Ye
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Hunan, China
| | - Jin Huang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Hunan, China
| | - Yan Shu
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland at Baltimore, Baltimore, MD, USA
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17
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Bowen A, Kos K, Whatmore J, Richardson S, Welters HJ. Wnt4 antagonises Wnt3a mediated increases in growth and glucose stimulated insulin secretion in the pancreatic beta-cell line, INS-1. Biochem Biophys Res Commun 2016; 479:793-799. [PMID: 27687546 DOI: 10.1016/j.bbrc.2016.09.130] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 09/25/2016] [Indexed: 12/18/2022]
Abstract
The Wnt signalling pathway in beta-cells has been linked to the development of type 2 diabetes. Investigating the impact of a non-canonical Wnt ligand, Wnt4, on beta-cell function we found that in INS-1 cells, Wnt4 was able to completely block Wnt3a stimulated cell growth and insulin secretion. However, despite high levels of Wnt4 protein being detected in INS-1 cells, reducing the expression of Wnt4 had no impact on cell growth or Wnt3a signalling. As such, the role of the endogenously expressed Wnt4 in beta-cells is unclear, but the data showing that Wnt4 can act as a negative regulator of canonical Wnt signalling in beta-cells suggests that this pathway could be a potential target for modulating beta-cell function.
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Affiliation(s)
- A Bowen
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, RILD Building, Barrack Road, Exeter EX2 5DW, UK
| | - K Kos
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, RILD Building, Barrack Road, Exeter EX2 5DW, UK
| | - J Whatmore
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, St Luke's Campus, Heavitree Road, Exeter EX1 2LU, UK
| | - S Richardson
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, RILD Building, Barrack Road, Exeter EX2 5DW, UK
| | - H J Welters
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, RILD Building, Barrack Road, Exeter EX2 5DW, UK.
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18
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sFRP-mediated Wnt sequestration as a potential therapeutic target for Alzheimer’s disease. Int J Biochem Cell Biol 2016; 75:104-11. [DOI: 10.1016/j.biocel.2016.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/06/2016] [Accepted: 04/06/2016] [Indexed: 01/28/2023]
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19
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Zhou JB, Yang JK, Zhang BH, Lu J. Interaction of Wnt pathway related variants with type 2 diabetes in a Chinese Han population. PeerJ 2015; 3:e1304. [PMID: 26509107 PMCID: PMC4621788 DOI: 10.7717/peerj.1304] [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: 06/25/2015] [Accepted: 09/17/2015] [Indexed: 11/20/2022] Open
Abstract
Aims. Epistasis from gene set based on the function-related genes may confer to the susceptibility of type 2 diabetes (T2D). The Wnt pathway has been reported to play an important role in the pathogenesis of T2D. Here we applied tag SNPs to explore the association between epistasis among genes from Wnt and T2D in the Han Chinese population. Methods. Variants of fourteen genes selected from Wnt pathways were performed to analyze epistasis. Gene–gene interactions in case-control samples were identified by generalized multifactor dimensionality reduction (GMDR) method. We performed a case-controlled association analysis on a total of 1,026 individual with T2D and 1,157 controls via tag SNPs in Wnt pathway. Results. In single-locus analysis, SNPs in four genes were significantly associated with T2D adjusted for multiple testing (rs7903146C in TCF7L2, p = 3.21∗10−3, OR = 1.39, 95% CI [1.31–1.47], rs12904944G in SMAD3, p = 2.51∗10−3, OR = 1.39, 95% CI [1.31–1.47], rs2273368C in WNT2B, p = 4.46∗10−3, OR = 1.23, 95% CI [1.11–1.32], rs6902123C in PPARD, p = 1.14∗10−2, OR = 1.40, 95% CI [1.32–1.48]). The haplotype TGC constructed by TCF7L2 (rs7903146), DKK1 (rs2241529) and BTRC (rs4436485) showed a significant association with T2D (OR = 0.750, 95% CI [0.579–0.972], P = 0.03). For epistasis analysis, the optimized combination was the two locus model of WNT2B rs2273368 and TCF7L2rs7903146, which had the maximum cross-validation consistency. This was 9 out of 10 for the sign test at 0.0107 level. The best combination increased the risk of T2D by 1.47 times (95% CI [1.13–1.91], p = 0.0039). Conclusions. Epistasis between TCF7L2 and WNT2B is associated with the susceptibility of T2D in a Han Chinese population. Our results were compatible with the idea of the complex nature of T2D that would have been missed using conventional tools.
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Affiliation(s)
- Jian-Bo Zhou
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University , Beijing , China
| | - Jin-Kui Yang
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University , Beijing , China ; Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University , Beijing , China
| | | | - Jing Lu
- Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University , Beijing , China
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20
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Sárközy M, Szűcs G, Pipicz M, Zvara Á, Éder K, Fekete V, Szűcs C, Bárkányi J, Csonka C, Puskás LG, Kónya C, Ferdinandy P, Csont T. The effect of a preparation of minerals, vitamins and trace elements on the cardiac gene expression pattern in male diabetic rats. Cardiovasc Diabetol 2015; 14:85. [PMID: 26126619 PMCID: PMC4499218 DOI: 10.1186/s12933-015-0248-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/17/2015] [Indexed: 02/06/2023] Open
Abstract
Background Diabetic patients have an increased risk of developing cardiovascular diseases, which are the leading cause of death in developed countries. Although multivitamin products are widely used as dietary supplements, the effects of these products have not been investigated in the diabetic heart yet. Therefore, here we investigated if a preparation of different minerals, vitamins, and trace elements (MVT) affects the cardiac gene expression pattern in experimental diabetes. Methods Two-day old male Wistar rats were injected with streptozotocin (i.p. 100 mg/kg) or citrate buffer to induce diabetes. From weeks 4 to 12, rats were fed with a vehicle or a MVT preparation. Fasting blood glucose measurement and oral glucose tolerance test were performed at week 12, and then total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41012 oligonucleotides. Results Significantly elevated fasting blood glucose concentration and impaired glucose tolerance were markedly improved by MVT-treatment in diabetic rats at week 12. Genes with significantly altered expression due to diabetes include functional clusters related to cardiac hypertrophy (e.g. caspase recruitment domain family, member 9; cytochrome P450, family 26, subfamily B, polypeptide; FXYD domain containing ion transport regulator 3), stress response (e.g. metallothionein 1a; metallothionein 2a; interleukin-6 receptor; heme oxygenase (decycling) 1; and glutathione S-transferase, theta 3), and hormones associated with insulin resistance (e.g. resistin; FK506 binding protein 5; galanin/GMAP prepropeptide). Moreover the expression of some other genes with no definite cardiac function was also changed such as e.g. similar to apolipoprotein L2; brain expressed X-linked 1; prostaglandin b2 synthase (brain). MVT-treatment in diabetic rats showed opposite gene expression changes in the cases of 19 genes associated with diabetic cardiomyopathy. In healthy hearts, MVT-treatment resulted in cardiac gene expression changes mostly related to immune response (e.g. complement factor B; complement component 4a; interferon regulatory factor 7; hepcidin). Conclusions MVT-treatment improved diagnostic markers of diabetes. This is the first demonstration that MVT-treatment significantly alters cardiac gene expression profile in both control and diabetic rats. Our results and further studies exploring the mechanistic role of individual genes may contribute to the prevention or diagnosis of cardiac complications in diabetes. Electronic supplementary material The online version of this article (doi:10.1186/s12933-015-0248-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Márta Sárközy
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | - Gergő Szűcs
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | - Márton Pipicz
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | - Ágnes Zvara
- Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary.
| | - Katalin Éder
- Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, Hungary.
| | - Veronika Fekete
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | | | | | - Csaba Csonka
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
| | - László G Puskás
- Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Szeged, Hungary.
| | - Csaba Kónya
- Béres Pharmaceuticals Ltd, Budapest, Hungary.
| | - Péter Ferdinandy
- Pharmahungary Group, Szeged, Hungary. .,Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary.
| | - Tamás Csont
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary.
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Mei H, Li L, Liu S, Jiang F, Griswold M, Mosley T. The uniform-score gene set analysis for identifying common pathways associated with different diabetes traits. BMC Genomics 2015; 16:336. [PMID: 25898945 PMCID: PMC4415316 DOI: 10.1186/s12864-015-1515-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 04/09/2015] [Indexed: 02/07/2023] Open
Abstract
Background Genetic heritability and expression study have shown that different diabetes traits have common genetic components and pathways. A computationally efficient pathway analysis of GWAS results will benefit post-GWAS study of SNP associations and identification of common genetic pathways from diabetes GWAS can help to improve understanding of the disease pathogenesis. Results We proposed a uniform-score gene-set analysis (USGSA) with implemented package to unify different gene measures by a uniform score for identifying pathways from GWAS data, and use a pre-generated permutation distribution table to quickly obtain multiple-testing adjusted p-value. Simulation studies of uniform score for four gene measures (minP, 2ndP, simP and fishP) have shown that USGSA has strictly controlled family-wise error rate. The power depends on types of gene measure. USGSA with a two-stage study strategy was applied to identify common pathways associated with diabetes traits based on public dbGaP GWAS results. The study identified 7 gene sets that contain binding motifs at promoter region of component genes for 5 transcription factors (TFs) of FOXO4, TCF3, NFAT, VSX1 and POU2F1, and 1 microRNA of mir-218. These gene sets include 25 common genes that are among top 5% of the gene associations over genome for all GWAS. Previous evidences showed that nearly all of these genes are mainly expressed in the brain. Conclusions USGSA is a computationally efficient approach for pathway analysis of GWAS data with promoted interpretability and comparability. The pathway analysis suggested that different diabetes traits share common pathways and component genes are potentially regulated by common TFs and microRNA. The result also indicated that the central nervous system has a critical role in diabetes pathogenesis. The findings will be important in formulating novel hypotheses for guiding follow-up studies. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1515-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hao Mei
- Center of Biostatistics & Bioinformatics, University of Mississippi Medical Center, Jackson, MS, USA. .,Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Lianna Li
- Department of Biology, Tougaloo College, Jackson, MS, USA.
| | - Shijian Liu
- Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Fan Jiang
- Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Michael Griswold
- Center of Biostatistics & Bioinformatics, University of Mississippi Medical Center, Jackson, MS, USA.
| | - Thomas Mosley
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS, USA.
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22
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Piran R, Lee SH, Li CR, Charbono A, Bradley LM, Levine F. Pharmacological induction of pancreatic islet cell transdifferentiation: relevance to type I diabetes. Cell Death Dis 2014; 5:e1357. [PMID: 25077543 PMCID: PMC4123101 DOI: 10.1038/cddis.2014.311] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 05/19/2014] [Accepted: 06/16/2014] [Indexed: 12/22/2022]
Abstract
Type I diabetes (T1D) is an autoimmune disease in which an immune response to pancreatic β-cells results in their loss over time. Although the conventional view is that this loss is due to autoimmune destruction, we present evidence of an additional phenomenon in which autoimmunity promotes islet endocrine cell transdifferentiation. The end result is a large excess of δ-cells, resulting from α- to β- to δ-cell transdifferentiation. Intermediates in the process of transdifferentiation were present in murine and human T1D. Here, we report that the peptide caerulein was sufficient in the context of severe β-cell deficiency to induce efficient induction of α- to β- to δ-cell transdifferentiation in a manner very similar to what occurred in T1D. This was demonstrated by genetic lineage tracing and time course analysis. Islet transdifferentiation proceeded in an islet autonomous manner, indicating the existence of a sensing mechanism that controls the transdifferentiation process within each islet. The finding of evidence for islet cell transdifferentiation in rodent and human T1D and its induction by a single peptide in a model of T1D has important implications for the development of β-cell regeneration therapies for diabetes.
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Affiliation(s)
- R Piran
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - S-H Lee
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - C-R Li
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - A Charbono
- Animal Facility, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - L M Bradley
- Infectious and Inflammatory Disease Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - F Levine
- Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
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Bergmann K, Sypniewska G. Secreted frizzled-related protein 4 (SFRP4) and fractalkine (CX3CL1) — Potential new biomarkers for β-cell dysfunction and diabetes. Clin Biochem 2014; 47:529-32. [DOI: 10.1016/j.clinbiochem.2014.03.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 03/03/2014] [Accepted: 03/06/2014] [Indexed: 10/25/2022]
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Taneera J, Fadista J, Ahlqvist E, Zhang M, Wierup N, Renström E, Groop L. Expression profiling of cell cycle genes in human pancreatic islets with and without type 2 diabetes. Mol Cell Endocrinol 2013; 375:35-42. [PMID: 23707792 DOI: 10.1016/j.mce.2013.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 04/30/2013] [Accepted: 05/01/2013] [Indexed: 02/07/2023]
Abstract
Microarray gene expression data were used to analyze the expression pattern of cyclin, cyclin-dependent kinase (CDKs) and cyclin-dependent kinase inhibitor (CDKIs) genes from human pancreatic islets with and without type 2 diabetes (T2D). Of the cyclin genes, CCNI was the most expressed. Data obtained from microarray and qRT-PCR showed higher expression of CCND1 in diabetic islets. Among the CDKs, CDK4, CDK8 and CDK9 were highly expressed, while CDK1 was expressed at low level. High expression of CDK18 was observed in diabetic islets. Of the CDKIs, CDKN1A expression was higher in diabetic islets in both microarray and qRT-PCR. Expression of CDKN1A, CDKN2A, CCNI2, CDK3 and CDK16 was correlated with age. Finally, eight SNPs in these genes were associated with T2D in the DIAGRAM database. Our data provide a comprehensive expression pattern of cell cycle genes in human islets. More human studies are required to confirm and reproduce animal studies.
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Affiliation(s)
- Jalal Taneera
- Lund University Diabetes Center, Department of Clinical Sciences, Diabetes & Endocrinology, Skåne University Hospital, Lund University, Malmö 20502, Sweden.
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25
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Mahdi T, Hänzelmann S, Salehi A, Muhammed SJ, Reinbothe TM, Tang Y, Axelsson AS, Zhou Y, Jing X, Almgren P, Krus U, Taneera J, Blom AM, Lyssenko V, Esguerra JLS, Hansson O, Eliasson L, Derry J, Zhang E, Wollheim CB, Groop L, Renström E, Rosengren AH. Secreted frizzled-related protein 4 reduces insulin secretion and is overexpressed in type 2 diabetes. Cell Metab 2012; 16:625-33. [PMID: 23140642 DOI: 10.1016/j.cmet.2012.10.009] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Revised: 09/10/2012] [Accepted: 10/22/2012] [Indexed: 12/12/2022]
Abstract
A plethora of candidate genes have been identified for complex polygenic disorders, but the underlying disease mechanisms remain largely unknown. We explored the pathophysiology of type 2 diabetes (T2D) by analyzing global gene expression in human pancreatic islets. A group of coexpressed genes (module), enriched for interleukin-1-related genes, was associated with T2D and reduced insulin secretion. One of the module genes that was highly overexpressed in islets from T2D patients is SFRP4, which encodes secreted frizzled-related protein 4. SFRP4 expression correlated with inflammatory markers, and its release from islets was stimulated by interleukin-1β. Elevated systemic SFRP4 caused reduced glucose tolerance through decreased islet expression of Ca(2+) channels and suppressed insulin exocytosis. SFRP4 thus provides a link between islet inflammation and impaired insulin secretion. Moreover, the protein was increased in serum from T2D patients several years before the diagnosis, suggesting that SFRP4 could be a potential biomarker for islet dysfunction in T2D.
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Affiliation(s)
- Taman Mahdi
- Lund University Diabetes Centre, Lund University, 20502 Malmö, Sweden
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26
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Yang H, Li Q, Lee JH, Shu Y. Reduction in Tcf7l2 expression decreases diabetic susceptibility in mice. Int J Biol Sci 2012; 8:791-801. [PMID: 22719219 PMCID: PMC3372883 DOI: 10.7150/ijbs.4568] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 05/29/2012] [Indexed: 02/02/2023] Open
Abstract
Objective: The WNT signaling pathway effector gene TCF7L2 has been associated with an increased risk of type 2 diabetes. However, it remains unclear how this gene affects diabetic pathogenesis. The goal of this study was to investigate the effects of Tcf7l2 haploinsufficiency on metabolic phenotypes in mice. Experimental Design:Tcf7l2 knockout (Tcf7l-/-) mice were generated. Because of the early mortality of Tcf7l2-/- mice, we characterized the metabolic phenotypes of heterozygous Tcf7l2+/- mice in comparison to the wild-type controls. The mice were fed a normal chow diet or a high fat diet (HFD) for 9 weeks. Results: The Tcf7l2+/- mice showed significant differences from the wild-type mice with regards to body weight, fasting glucose and insulin levels. Tcf7l2+/- mice displayed improved glucose tolerance. In the liver of Tcf7l2+/- mice fed on the HFD, reduced lipogenesis and hepatic triglyceride levels were observed when compared with those of wild-type mice. Furthermore, the Tcf7l2+/- mice fed on the HFD exhibited decreased peripheral fat deposition. Immunohistochemistry in mouse pancreatic islets showed that endogenous expression of Tcf7l2 was upregulated in the wild-type mice, but not in the Tcf7l2+/- mice, after feeding with the HFD. However, the haploinsufficiency of Tcf7l2 in mouse pancreatic islets resulted in little changes in glucose-stimulated insulin secretion. Conclusion: These results suggest that decreased expression of Tcf7l2 confers reduction of diabetic susceptibility in mice via regulation on the metabolism of glucose and lipid.
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Affiliation(s)
- Hyekyung Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, USA
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Včelák J, Vejražková D, Vaňková M, Lukášová P, Bradnová O, Hálková T, Bešťák J, Andělová K, Kvasničková H, Hoskovcová P, Vondra K, Vrbíková J, Bendlová B. T2D risk haplotypes of the TCF7L2 gene in the Czech population sample: the association with free fatty acids composition. Physiol Res 2012; 61:229-40. [PMID: 22480428 DOI: 10.33549/physiolres.932272] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The association of transcription factor 7-like 2 (TCF7L2) gene variants with the pathogenesis of T2D, gestational diabetes and polycystic ovary syndrome (PCOS) was examined. The study involved 1460 individuals: 347 T2D patients (D); 261 gestational diabetics (G); 147 offspring of T2D (O); 329 women with PCOS, and 376 controls (C). The SNPs: rs7901695; rs7903146; rs12255372 in the TCF7L2 gene were genotyped. Anthropometric and biochemical parameters, oGTT derived indices were assessed. In addition, free fatty acids (FFAs) were evaluated in 183 non-diabetic women. The CTT haplotype showed the strongest association with T2D with OR 1.57, p=0.0003. The frequency of the CTT/CTT haplotype was decreasing in following order: D 10.6, O 9.5, G 6.1, C 5.3 and PCOS 4.9 [%]. Among CTT carriers, significantly decreased levels of oGTT-stimulated insulin and C-peptide as well as proportions of fasting PUFAs were observed. The carriership of CTG/TCG was associated with gestational diabetes, OR 2.59, p=0.036. The association of TCF7L2 haplotypes with T2D and gestational diabetes but not with PCOS was confirmed. Novel association of TCF7L2 with FFAs composition was found.
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Affiliation(s)
- J Včelák
- Department of Molecular Endocrinology, Institute of Endocrinology, Prague, Czech Republic.
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Palsgaard J, Emanuelli B, Winnay JN, Sumara G, Karsenty G, Kahn CR. Cross-talk between insulin and Wnt signaling in preadipocytes: role of Wnt co-receptor low density lipoprotein receptor-related protein-5 (LRP5). J Biol Chem 2012; 287:12016-26. [PMID: 22337886 DOI: 10.1074/jbc.m111.337048] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Disturbed Wnt signaling has been implicated in numerous diseases, including type 2 diabetes and the metabolic syndrome. In the present study, we have investigated cross-talk between insulin and Wnt signaling pathways using preadipocytes with and without knockdown of the Wnt co-receptors LRP5 and LRP6 and with and without knock-out of insulin and IGF-1 receptors. We find that Wnt stimulation leads to phosphorylation of insulin signaling key mediators, including Akt, GSK3β, and ERK1/2, although with a lower fold stimulation and slower time course than observed for insulin. These Wnt effects are insulin/IGF-1 receptor-dependent and are lost in insulin/IGF-1 receptor double knock-out cells. Conversely, in LRP5 knockdown preadipocytes, insulin-induced phosphorylation of IRS1, Akt, GSK3β, and ERK1/2 is highly reduced. This effect is specific to insulin, as compared with IGF-1, stimulation and appears to be due to an inducible interaction between LRP5 and the insulin receptor as demonstrated by co-immunoprecipitation. These data demonstrate that Wnt and insulin signaling pathways exhibit cross-talk at multiple levels. Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent on insulin/IGF-1 receptors. Insulin signaling also involves the Wnt co-receptor LRP5, which has a positive effect on insulin signaling. Thus, altered Wnt and LRP5 activity can serve as modifiers of insulin action and insulin resistance in the pathophysiology of diabetes and metabolic syndrome.
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Affiliation(s)
- Jane Palsgaard
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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29
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Baquié M, St-Onge L, Kerr-Conte J, Cobo-Vuilleumier N, Lorenzo PI, Jimenez Moreno CM, Cederroth CR, Nef S, Borot S, Bosco D, Wang H, Marchetti P, Pattou F, Wollheim CB, Gauthier BR. The liver receptor homolog-1 (LRH-1) is expressed in human islets and protects {beta}-cells against stress-induced apoptosis. Hum Mol Genet 2011; 20:2823-33. [PMID: 21536586 DOI: 10.1093/hmg/ddr193] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Liver receptor homolog (LRH-1) is an orphan nuclear receptor (NR5A2) that regulates cholesterol homeostasis and cell plasticity in endodermal-derived tissues. Estrogen increases LRH-1 expression conveying cell protection and proliferation. Independently, estrogen also protects isolated human islets against cytokine-induced apoptosis. Herein, we demonstrate that LRH-1 is expressed in islets, including β-cells, and that transcript levels are modulated by 17β-estradiol through the estrogen receptor (ER)α but not ERβ signaling pathway. Repression of LRH-1 by siRNA abrogated the protective effect conveyed by estrogen on rat islets against cytokines. Adenoviral-mediated overexpression of LRH-1 in human islets did not alter proliferation but conferred protection against cytokines and streptozotocin-induced apoptosis. Expression levels of the cell cycle genes cyclin D1 and cyclin E1 as well as the antiapoptotic gene bcl-xl were unaltered in LRH-1 expressing islets. In contrast, the steroidogenic enzymes CYP11A1 and CYP11B1 involved in glucocorticoid biosynthesis were both stimulated in transduced islets. In parallel, graded overexpression of LRH-1 dose-dependently impaired glucose-induced insulin secretion. Our results demonstrate the crucial role of the estrogen target gene nr5a2 in protecting human islets against-stressed-induced apoptosis. We postulate that this effect is mediated through increased glucocorticoid production that blunts the pro-inflammatory response of islets.
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Affiliation(s)
- Mathurin Baquié
- Department of Sensory Neuroscience, The Rockefeller University, New York, NY, USA
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30
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Gjesing AP, Kjems LL, Vestmar MA, Grarup N, Linneberg A, Deacon CF, Holst JJ, Pedersen O, Hansen T. Carriers of the TCF7L2 rs7903146 TT genotype have elevated levels of plasma glucose, serum proinsulin and plasma gastric inhibitory polypeptide (GIP) during a meal test. Diabetologia 2011; 54:103-10. [PMID: 20957343 DOI: 10.1007/s00125-010-1940-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 08/19/2010] [Indexed: 12/21/2022]
Abstract
AIMS/HYPOTHESIS The transcription factor 7-like 2 (TCF7L2) rs7903146 T allele associates with type 2 diabetes in several populations, possibly mediated via decreased incretin secretion and/or action and altered beta and alpha cell function. We aimed to study circulating levels of glucose, proinsulin, insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2) and gastric inhibitory polypeptide (GIP) among individuals carrying the high-risk rs7903146 TT genotype and low-risk CC genotype following a meal test. METHODS A meal challenge was performed in 31 glucose-tolerant men (age 54 ± 7 years and BMI 26 ± 3 kg/m²) with rs7903146 TT genotype and 31 glucose-tolerant age- and BMI-matched men with CC genotype (age 53 ± 6 years and BMI 26 ± 3 kg/m²). Serum proinsulin, insulin, C-peptide and plasma glucose, glucagon, GLP-1, GLP-2 and GIP were obtained 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 180, 210, and 240 min after ingestion of a standardised breakfast meal. RESULTS An elevated incremental AUC for plasma glucose was observed among TT genotype carriers (CC carriers 21.8 ± 101.9 mmol/l × min vs TT carriers 97.9 ± 89.2 mmol/l × min, p = 0.001). TT carriers also had increased AUCs for proinsulin (CC carriers 6,030 ± 3,001 pmol/l × min vs TT carriers 6,917 ± 4,820 pmol/l × min, p = 0.03), C-peptide (CC carriers 397.6 ± 131.9 nmol/l × min vs TT carriers 417.1 ± 109.3 nmol/l × min, p = 0.04) and GIP (CC carriers 12,310 ± 3,840 pmol/l × min vs TT carriers 14,590 ± 5,910 pmol/l × min, p = 0.004). CONCLUSIONS/INTERPRETATION Middle-aged normoglycaemic individuals carrying the rs7903146 TCF7L2 risk TT genotype show early signs of dysregulated glucose metabolism, decreased processing of proinsulin and elevated GIP secretion following a meal challenge.
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Affiliation(s)
- A P Gjesing
- Steno Diabetes Center, Hagedorn Research Institute, Gentofte, Denmark.
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31
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Marselli L, Thorne J, Dahiya S, Sgroi DC, Sharma A, Bonner-Weir S, Marchetti P, Weir GC. Gene expression profiles of Beta-cell enriched tissue obtained by laser capture microdissection from subjects with type 2 diabetes. PLoS One 2010; 5:e11499. [PMID: 20644627 PMCID: PMC2903480 DOI: 10.1371/journal.pone.0011499] [Citation(s) in RCA: 215] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Accepted: 06/06/2010] [Indexed: 12/26/2022] Open
Abstract
Background Changes in gene expression in pancreatic beta-cells from type 2 diabetes (T2D) should provide insights into their abnormal insulin secretion and turnover. Methodology/Principal Findings Frozen sections were obtained from cadaver pancreases of 10 control and 10 T2D human subjects. Beta-cell enriched samples were obtained by laser capture microdissection (LCM). RNA was extracted, amplified and subjected to microarray analysis. Further analysis was performed with DNA-Chip Analyzer (dChip) and Gene Set Enrichment Analysis (GSEA) software. There were changes in expression of genes linked to glucotoxicity. Evidence of oxidative stress was provided by upregulation of several metallothionein genes. There were few changes in the major genes associated with cell cycle, apoptosis or endoplasmic reticulum stress. There was differential expression of genes associated with pancreatic regeneration, most notably upregulation of members of the regenerating islet gene (REG) family and metalloproteinase 7 (MMP7). Some of the genes found in GWAS studies to be related to T2D were also found to be differentially expressed. IGF2BP2, TSPAN8, and HNF1B (TCF2) were upregulated while JAZF1 and SLC30A8 were downregulated. Conclusions/Significance This study made possible by LCM has identified many novel changes in gene expression that enhance understanding of the pathogenesis of T2D.
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Affiliation(s)
- Lorella Marselli
- Section on Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jeffrey Thorne
- Section on Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sonika Dahiya
- Molecular Pathology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Dennis C. Sgroi
- Molecular Pathology Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Arun Sharma
- Section on Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Susan Bonner-Weir
- Section on Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Piero Marchetti
- Section of Endocrinology and Metabolism of Organ Transplantation, Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - Gordon C. Weir
- Section on Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center and the Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Wong VSC, Yeung A, Schultz W, Brubaker PL. R-spondin-1 is a novel beta-cell growth factor and insulin secretagogue. J Biol Chem 2010; 285:21292-302. [PMID: 20442404 PMCID: PMC2898385 DOI: 10.1074/jbc.m110.129874] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Indexed: 12/13/2022] Open
Abstract
R-spondin-1 (Rspo1) is an intestinal growth factor known to exert its effects through activation of the canonical Wnt (cWnt) signaling pathway and subsequent expression of cWnt target genes. We have detected Rspo1 mRNA in murine islets and the murine MIN6 and betaTC beta-cell lines, and Rspo1 protein in MIN6 beta-cells. Rspo1 activated cWnt signaling in MIN6 beta-cells by increasing nuclear beta-catenin and c-myc, a cWnt target gene. Rspo1 also induced insulin mRNA expression in MIN6 cells. Analysis of MIN6 and mouse beta-cell proliferation by [(3)H]thymidine and BrdU incorporation, respectively, revealed that Rspo1 stimulated cell growth. Incubation of MIN6 and mouse beta-cells with cytokines (IL1beta/TNFalpha/interferon-gamma) significantly increased cellular apoptosis; this increase was abolished by pretreatment with Rspo1. Rspo1 also stimulated insulin secretion in a glucose-independent fashion. We further demonstrated that the glucagon-like peptide-1 receptor agonist, exendin4 (EX4), stimulated Rspo1 mRNA transcript levels in MIN6 cells in a glucose-, time-, dose-, and PI3-kinase-dependent fashion. This effect was not limited to this beta-cell line, as similar time-dependent increases in Rspo1 were also observed in the betaTC beta-cell line and mouse islets in response to EX4 treatment. Together, these studies demonstrate that Rspo1 is a novel beta-cell growth factor and insulin secretagogue that is regulated by EX4. These findings suggest that Rspo1 and the cWnt signaling pathway may serve as a novel target to enhance beta-cell growth and function in patients with type 2 diabetes.
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Affiliation(s)
| | | | | | - Patricia L. Brubaker
- From the Departments of Physiology and
- Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Liu Z, Habener JF. Wnt signaling in pancreatic islets. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:391-419. [PMID: 20217507 DOI: 10.1007/978-90-481-3271-3_17] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The Wnt signaling pathway is critically important not only for stem cell amplification, differentiation, and migration, but also is important for organogenesis and the development of the body plan. Beta-catenin/TCF7L2-dependent Wnt signaling (the canonical pathway) is involved in pancreas development, islet function, and insulin production and secretion. The glucoincretin hormone glucagon-like peptide-1 and the chemokine stromal cell-derived factor-1 modulate canonical Wnt signaling in beta-cells which is obligatory for their mitogenic and cytoprotective actions. Genome-wide association studies have uncovered 19 gene loci that confer susceptibility for the development of type 2 diabetes. At least 14 of these diabetes risk alleles encode proteins that are implicated in islet growth and functioning. Seven of them are either components of, or known target genes for, Wnt signaling. The transcription factor TCF7L2 is particularly strongly associated with risk for diabetes and appears to be fundamentally important in both canonical Wnt signaling and beta-cell functioning. Experimental loss of TCF7L2 function in islets and polymorphisms in TCF7L2 alleles in humans impair glucose-stimulated insulin secretion, suggesting that perturbations in the Wnt signaling pathway may contribute substantially to the susceptibility for, and pathogenesis of, type 2 diabetes. This review focuses on considerations of the hormonal regulation of Wnt signaling in islets and implications for mutations in components of the Wnt signaling pathway as a source for risk-associated alleles for type 2 diabetes.
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Affiliation(s)
- Zhengyu Liu
- Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Boston, MA 02114, USA.
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Abstract
At the cellular level, the biological processes of cell proliferation, growth arrest, differentiation and apoptosis are all tightly coupled to appropriate alterations in metabolic status. In the case of cell proliferation, this requires redirecting metabolic pathways to provide the fuel and basic components for new cells. Ultimately, the successful co-ordination of cell-specific biology with cellular metabolism underscores multicellular processes as diverse as embryonic development, adult tissue remodelling and cancer cell biology. The Wnt signalling network has been implicated in all of these areas. While each of the Wnt-dependent signalling pathways are being individually delineated in a range of experimental systems, our understanding of how they integrate and regulate cellular metabolism is still in its infancy. In the present review we reassess the roles of Wnt signalling in functionally linking cellular metabolism to tissue development and function.
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Affiliation(s)
- Jaswinder K Sethi
- Department of Clinical Biochemistry, University of Cambridge Metabolic Research Laboratories, Level 4, Institute of Metabolic Science, Box 289, Addenbrooke's Hospital, Cambridge CB20QQ, U.K.
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Figeac F, Uzan B, Faro M, Chelali N, Portha B, Movassat J. Neonatal growth and regeneration of beta-cells are regulated by the Wnt/beta-catenin signaling in normal and diabetic rats. Am J Physiol Endocrinol Metab 2010; 298:E245-56. [PMID: 19920216 DOI: 10.1152/ajpendo.00538.2009] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Wnt/beta-catenin signaling is critical for a variety of fundamental cellular processes. Here, we investigated the implication of the Wnt/beta-catenin signaling in the in vivo regulation of beta-cell growth and regeneration in normal and diabetic rats. To this aim, TCF7L2, the distal effector of the canonical Wnt pathway, was knocked down in groups of normal and diabetic rats by the use of specific antisense morpholino-oligonucleotides. In other groups of diabetic rats, the Wnt/beta-catenin pathway was activated by the inhibition of its negative regulator GSK-3beta. GSK-3beta was inactivated by either LiCl or anti-GSK-3beta oligonucleotides. The beta-cell mass was evaluated by morphometry. beta-cell proliferation was assessed in vivo and in vitro by BrdU incorporation method. In vivo beta-cell neogenesis was estimated by the evaluation of PDX1-positive ductal cells and GLUT2-positive ductal cells and the number of beta cells budding from the ducts. We showed that the in vivo disruption of the canonical Wnt pathway resulted in the alteration of normal and compensatory growth of beta-cells mainly through the inhibition of beta-cell proliferation. Conversely, activation of the Wnt pathway through the inhibition of GSK-3beta had a significant stimulatory effect on beta-cell regeneration in diabetic rats. In vitro, GSK-3beta inactivation resulted in the stimulation of beta-cell proliferation. This was mediated by the stabilization of beta-catenin and the induction of cyclin D. Taken together, our results demonstrate the involvement of the canonical Wnt signaling in the neonatal regulation of normal and regenerative growth of pancreatic beta-cells. Moreover, we provide evidence that activation of this pathway by pharmacological maneuvers can efficiently improve beta-cell regeneration in diabetic rats. These findings might have potential clinical applications in the regenerative therapy of diabetes.
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Affiliation(s)
- Florence Figeac
- University Paris Diderot-Centre National de la Recherche Scientifique Equipe d'Accueil Conventionnée 4413, Laboratory of Biology and Pathology of the Endocrine Pancreas, Paris, France
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Sun J, Wang D, Jin T. Insulin alters the expression of components of the Wnt signaling pathway including TCF-4 in the intestinal cells. Biochim Biophys Acta Gen Subj 2010; 1800:344-51. [PMID: 20056134 DOI: 10.1016/j.bbagen.2009.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Revised: 12/17/2009] [Accepted: 12/24/2009] [Indexed: 01/27/2023]
Abstract
BACKGROUND Epidemiological and experimental evidence that support the correlation between Type 2 diabetes mellitus (T2D) and increased risks of colorectal cancer formation have led us to hypothesize the existence of molecular crosstalk between insulin and canonical Wnt signaling pathways. Insulin was shown to stimulate Wnt target gene expression, utilizing the effector of the Wnt signaling pathway. Whether insulin affects expression of components of Wnt pathway has not been extensively examined. METHODS cDNA microarray was utilized to assess the effect of insulin on gene expression profile in the rat intestinal non-cancer IEC-6 cell line, followed by real-time RT-PCR, Western blotting and reporter gene analyses in intestinal cancer and non-cancer cells. RESULTS Insulin was shown to alter the expression of a dozen of Wnt pathway related genes including TCF-4 (=TCF7L2) and frizzled- (Fzd-4). The stimulatory effect of insulin on TCF-4 expression was then confirmed by real-time RT-PCR, Western blotting and luciferase reporter analyses, while the activation on Fzd-4 was confirmed by real-time PCR. GENERAL SIGNIFICANCE Our observations suggest that insulin may crosstalk with the Wnt signaling pathway in a multi-level fashion, involving insulin regulation of the expression of Wnt target genes, a Wnt receptor, as well as mediators of the Wnt signaling pathway.
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Affiliation(s)
- Jane Sun
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada; Division of Cell and Molecular Biology, University Health Network, Canada
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Portha B, Lacraz G, Chavey A, Figeac F, Fradet M, Tourrel-Cuzin C, Homo-Delarche F, Giroix MH, Bailbé D, Gangnerau MN, Movassat J. Islet structure and function in the GK rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 654:479-500. [PMID: 20217511 DOI: 10.1007/978-90-481-3271-3_21] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Type 2 diabetes mellitus (T2D) arises when the endocrine pancreas fails to secrete sufficient insulin to cope with the metabolic demand because of beta-cell secretory dysfunction and/or decreased beta-cell mass. Defining the nature of the pancreatic islet defects present in T2D has been difficult, in part because human islets are inaccessible for direct study. This review is aimed to illustrate to what extent the Goto-Kakizaki rat, one of the best characterized animal models of spontaneous T2D, has proved to be a valuable tool offering sufficient commonalities to study this aspect. A comprehensive compendium of the multiple functional GK islet abnormalities so far identified is proposed in this perspective. The pathogenesis of defective beta-cell number and function in the GK model is also discussed. It is proposed that the development of T2D in the GK model results from the complex interaction of multiple events: (i) several susceptibility loci containing genes responsible for some diabetic traits (distinct loci encoding impairment of beta-cell metabolism and insulin exocytosis, but no quantitative trait locus for decreased beta-cell mass); (ii) gestational metabolic impairment inducing an epigenetic programming of the offspring pancreas (decreased beta-cell neogenesis and proliferation) transmitted over generations; and (iii) loss of beta-cell differentiation related to chronic exposure to hyperglycaemia/hyperlipidaemia, islet inflammation, islet oxidative stress, islet fibrosis and perturbed islet vasculature.
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Affiliation(s)
- Bernard Portha
- Laboratoire B2PE, Unité BFA, Université Paris-Diderot et CNRS EAC4413, F - 75205 Paris Cedex13, France.
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Abstract
Prospects for inducing endogenous beta-cell regeneration in the pancreas, one of the most attractive approaches to reverse type 1 and type 2 diabetes, have gained substantially from recent evidence that cells in the adult pancreas exhibit more plasticity than previously recognized. There are two major pathways to beta-cell regeneration, beta-cell replication and beta-cell neogenesis. Substantial evidence for a role for both processes exists in different models. While beta-cell replication clearly occurs during development and early in life, the potential for replication appears to decline substantially with age. In contrast, we have demonstrated that the exocrine compartment of the adult human pancreas contains a facultative stem cell that can differentiate into beta-cells under specific circumstances. We have favoured the idea that, similar to models described in liver regeneration, beta-cell mass can be increased either by neogenesis or replication, depending on the intensity of different stimuli or stressors. Understanding the nature of endocrine stem/progenitor cells and the mechanism by which external stimuli mobilize them to exhibit endocrine differentiation is central for success in therapeutic approaches to induce meaningful endogenous beta-cell neogenesis.
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Affiliation(s)
- C Demeterco
- Department of Pediatrics, University of California San Diego, Rady Children's Hospital, La Jolla, USA
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Affiliation(s)
- E R Pearson
- Biomedical Research Institute, University of Dundee, Dundee, UK.
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