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Li H, Yang Q, Huang Z, Liang C, Zhang DH, Shi HT, Du JQ, Du BB, Zhang YZ. Dual-specificity phosphatase 12 attenuates oxidative stress injury and apoptosis in diabetic cardiomyopathy via the ASK1-JNK/p38 signaling pathway. Free Radic Biol Med 2022; 192:13-24. [PMID: 36108935 DOI: 10.1016/j.freeradbiomed.2022.09.004] [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: 06/28/2022] [Revised: 08/27/2022] [Accepted: 09/07/2022] [Indexed: 10/31/2022]
Abstract
Diabetic cardiomyopathy (DCM) is ventricular dysfunction that occurs in patients with diabetes mellitus (DM), independent of recognized risk factors, such as coronary artery disease, hypertension, and valvular heart disease. Dual-specificity phosphatase 12 (DUSP12) is a dual-specificity phosphatase expressed in all tissues. Genome-wide linkage studies have found an association between DUSP12 and type 2 diabetes (T2D). However, the role of DUSP12 in DCM remains largely unknown. Ubiquitously expressed DUSP12 is involved in nonalcoholic fatty liver disease, bacterial infection, and myocardial hypertrophy and plays a critical role in tumorigenesis. Herein, we observed an increased expression of DUSP12 in a hyperglycemia cell model and a high-fat diet (HFD) mouse model. Heart-specific DUSP12-deficient mice showed severe cardiac dysfunction and remodeling induced by an HFD. DUSP12 deficiency exacerbated oxidative stress injury and apoptosis, whereas DUSP12 overexpression had the opposite effect. At the molecular level, DUSP12 physically bound to apoptotic signal-regulated kinase 1 (ASK1), promoted its dephosphorylation, and inhibited its action on c-Jun N-terminal kinase and p38 mitogen-activated protein kinase. Rescue experiments have shown that oxidative stress injury and apoptosis, exacerbated by DUSP12 deficiency, are alleviated by ASK1 inhibition. Therefore, we consider DUSP12 an important signaling pathway in DCM.
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Affiliation(s)
- Huan Li
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Qin Yang
- Department of Cardiology, Huanggang Central Hospital, Huanggang, 438021, China
| | - Zhen Huang
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Cui Liang
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Dian-Hong Zhang
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Hui-Ting Shi
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Jia-Qi Du
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China
| | - Bin-Bin Du
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China.
| | - Yan-Zhou Zhang
- Cardiovascular Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450052, China.
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Enriched Alternative Splicing in Islets of Diabetes-Susceptible Mice. Int J Mol Sci 2021; 22:ijms22168597. [PMID: 34445304 PMCID: PMC8395343 DOI: 10.3390/ijms22168597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 12/30/2022] Open
Abstract
Dysfunctional islets of Langerhans are a hallmark of type 2 diabetes (T2D). We hypothesize that differences in islet gene expression alternative splicing which can contribute to altered protein function also participate in islet dysfunction. RNA sequencing (RNAseq) data from islets of obese diabetes-resistant and diabetes-susceptible mice were analyzed for alternative splicing and its putative genetic and epigenetic modulators. We focused on the expression levels of chromatin modifiers and SNPs in regulatory sequences. We identified alternative splicing events in islets of diabetes-susceptible mice amongst others in genes linked to insulin secretion, endocytosis or ubiquitin-mediated proteolysis pathways. The expression pattern of 54 histones and chromatin modifiers, which may modulate splicing, were markedly downregulated in islets of diabetic animals. Furthermore, diabetes-susceptible mice carry SNPs in RNA-binding protein motifs and in splice sites potentially responsible for alternative splicing events. They also exhibit a larger exon skipping rate, e.g., in the diabetes gene Abcc8, which might affect protein function. Expression of the neuronal splicing factor Srrm4 which mediates inclusion of microexons in mRNA transcripts was markedly lower in islets of diabetes-prone compared to diabetes-resistant mice, correlating with a preferential skipping of SRRM4 target exons. The repression of Srrm4 expression is presumably mediated via a higher expression of miR-326-3p and miR-3547-3p in islets of diabetic mice. Thus, our study suggests that an altered splicing pattern in islets of diabetes-susceptible mice may contribute to an elevated T2D risk.
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3
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Hui Z, Jie H, Fan GH. Expression of DUSP12 Reduces Lung Vascular Endothelial Cell Damage in a Murine Model of Lipopolysaccharide-Induced Acute Lung Injury via the Apoptosis Signal-Regulating Kinase 1 (ASK1)-Jun N-Terminal Kinase Activation (JNK) Pathway. Med Sci Monit 2021; 27:e930429. [PMID: 33811209 PMCID: PMC8025659 DOI: 10.12659/msm.930429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Acute lung injury (ALI) results from damage to the alveolar capillary endothelial cells and can result in acute respiratory distress syndrome (ARDS). This study aimed to investigate murine lung vascular endothelial cells (MLECs) damage in a murine model of lipopolysaccharide (LPS)-induced ALI. MATERIAL AND METHODS Mice were injected with LPS to induce an acute lung injury model. An adenovirus transfection system was used to overexpress or knockdown DUSP12 in mice. MLECs were isolated, cultured and transfected with DUSP12-overexpressing adenovirus or with DUSP12 siRNA to knockdown DUSP12. LPS was used to establish a cell injury model. ELISA and RT-PCR were used to examine cell inflammation. LPS-induced oxidative stress was also evaluated using commercial kits. RESULTS A decreased level of DUSP12 was observed in MLECs treated with LPS. DUSP12 overexpression in mice attenuated LPS-induced lung inflammation and lung injury, as reflected by reduced levels of proinflammatory cytokines. Mice with DUSP12 knockdown exhibited worsened lung inflammation and injury. In vitro, DUSP12 overexpression in endothelial cells ameliorated LPS-induced inflammation, apoptosis, and oxidative stress. DUSP12 silencing in endothelial cells aggravated LPS-induced inflammation, apoptosis, and oxidative stress. Furthermore, we found that DUSP12 directly bound to apoptosis signal-regulating kinase 1 (ASK1) to inhibit Jun N-terminal kinase activation (JNK). A JNK1/2 inhibitor and ASK1 siRNA ameliorated the exacerbating effects of DUSP12 knockdown in vitro. CONCLUSIONS Our data demonstrated that DUSP12 suppressed MLEC injury in response to LPS insult by regulating the ASK1/JNK pathway.
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Affiliation(s)
- Zhao Hui
- Department of Interventional Radiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, P.R. China
| | - Huang Jie
- Department of Thoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, P.R. China
| | - Guo-Hua Fan
- Department of Thoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, P.R. China
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4
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Cho SSL, Han J, James SJ, Png CW, Weerasooriya M, Alonso S, Zhang Y. Dual-Specificity Phosphatase 12 Targets p38 MAP Kinase to Regulate Macrophage Response to Intracellular Bacterial Infection. Front Immunol 2017; 8:1259. [PMID: 29062315 PMCID: PMC5640881 DOI: 10.3389/fimmu.2017.01259] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/21/2017] [Indexed: 12/24/2022] Open
Abstract
The mitogen-activated protein kinase (MAPK) cascades are activated in innate immune cells such as macrophages upon the detection of microbial infection, critically regulating the expression of proinflammatory cytokines and chemokines such as TNF-α, IL-6, and MCP-1. As a result, activation of MAPKs is tightly regulated to ensure appropriate and adequate immune responses. Dual-specificity phosphatases (DUSPs) are a family of proteins which specifically dephosphorylates threonine and tyrosine residues essential for MAPK activation to negatively regulate their activation. DUSP12 is a member of atypical DUSPs that lack MAPK-binding domain. Its substrate and function in immune cells are unknown. In this study, we demonstrated that DUSP12 is able to interact with all the three groups of MAPKs, including extracellular signal-regulated protein kinase, JNK, and p38. To investigate the function of DUSP12 in macrophages in response to TLR activation and microbial infection, we established RAW264.7 cell lines stably overexpressing DUSP12 and found that overexpression of DUSP12 inhibited proinflammatory cytokine and chemokine production in response to TLR4 activation, heat-inactivated Mycobacterium tuberculosis stimulation as well as infections by intracellular bacteria including Listeria moncytogenesis and Mycobacterium bovis BCG by specifically inhibiting p38 and JNK. In addition, a scaffold protein known as signal transducing adaptor protein 2 (STAP2), was found to mediate the interaction between DUSP12 and p38. Thus, DUSP12 is a bona fide MAPK phosphatase, playing an important role in MAPK-regulated responses to bacterial infection. Our study provides a model where atypical DUSPs regulate MAPKs via scaffold, thereby regulating immune responses to microbial infection.
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Affiliation(s)
- Sharol Su Lei Cho
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Jian Han
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Sharmy J James
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Chin Wen Png
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Madhushanee Weerasooriya
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Sylvie Alonso
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Yongliang Zhang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
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5
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Hatzihristidis T, Desai N, Hutchins AP, Meng TC, Tremblay ML, Miranda-Saavedra D. A Drosophila-centric view of protein tyrosine phosphatases. FEBS Lett 2015; 589:951-66. [PMID: 25771859 DOI: 10.1016/j.febslet.2015.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/30/2022]
Abstract
Most of our knowledge on protein tyrosine phosphatases (PTPs) is derived from human pathologies and mouse knockout models. These models largely correlate well with human disease phenotypes, but can be ambiguous due to compensatory mechanisms introduced by paralogous genes. Here we present the analysis of the PTP complement of the fruit fly and the complementary view that PTP studies in Drosophila will accelerate our understanding of PTPs in physiological and pathological conditions. With only 44 PTP genes, Drosophila represents a streamlined version of the human complement. Our integrated analysis places the Drosophila PTPs into evolutionary and functional contexts, thereby providing a platform for the exploitation of the fly for PTP research and the transfer of knowledge onto other model systems.
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Affiliation(s)
- Teri Hatzihristidis
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Nikita Desai
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Andrew P Hutchins
- Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510530, China
| | - Tzu-Ching Meng
- Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan; Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Michel L Tremblay
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
| | - Diego Miranda-Saavedra
- World Premier International (WPI) Immunology Frontier Research Center (IFReC), Osaka University, 3-1 Yamadaoka, Suita 565-0871, Osaka, Japan; Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain; IE Business School, IE University, María de Molina 31 bis, 28006 Madrid, Spain.
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6
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Gu N, Ma X, Zhang J, Dong A, Jin M, Feng N, Zhang H, Guo X. Obesity has an interactive effect with genetic variation in the activating transcription factor 6 gene on the risk of pre-diabetes in individuals of Chinese Han descent. PLoS One 2014; 9:e109805. [PMID: 25302688 PMCID: PMC4193822 DOI: 10.1371/journal.pone.0109805] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/13/2014] [Indexed: 11/19/2022] Open
Abstract
Endoplasmic reticulum (ER) stress is one of the contributing factors to the development of β-cell failure in type 2 diabetes. ER stress response through ATF6 has been shown to play an important role in insulin resistance and pancreatic β-cell function. We investigated whether genetic polymorphisms in ATF6 were associated with the risk of pre-diabetes in a Chinese Han population, and whether they had a synergistic effect with obesity. Our samples included 828 individuals who were diagnosed as pre-diabetic, and 620 controls. The minor allele A at rs2340721 was associated with increased risk for pre-diabetes(p = 0.013), and this association was still significant after adjusting for gender, age, body mass index (BMI), and waist-hip ratio(p' = 0.011). BMI, treated as a continuous variable, and rs2340721 had an interactive effect on pre-diabetic risk(p for interaction = 0.003, β = 0.106). Carriers of GG at rs7522210 were also at a higher risk compared to non-carriers (OR = 1.390, 95%CI:1.206-1.818, p = 0.013, adjusted OR' = 1.516, 95%CI:1.101-2.006, p' = 0.006). GG homozygotes had increased fasting blood glucose (FBG) levels(GG vs CX: 5.6 ± 0.52 vs 5.5 ± 0.57 mmol/L, p = 0.016), lower insulin levels (0,30,120 minutes after glucose load) (p < 0.05), and reduced areas under the insulin curve than non-carriers(GG vs CX:67.3(44.2-102.3) vs 73.1(49.4-111.4), p = 0.014). rs10918270 was associated with FBG, and rs4657103 with 2 hour glucose levels after a 75 g glucose load. We also identified a haplotype of TTAG composed of rs4657103, rs2134697, rs2340721, and rs12079579, which was associated with pre-diabetes. The genetic variation in ATF6 is associated with pre-diabetes and has interactive effects with BMI on pre-diabetes in the Chinese Han population.
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Affiliation(s)
- Nan Gu
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Xiaowei Ma
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Junqing Zhang
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Aimei Dong
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Mengmeng Jin
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Nan Feng
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Hong Zhang
- Endocrinology Department, First Hospital, Peking University, Beijing, China
| | - Xiaohui Guo
- Endocrinology Department, First Hospital, Peking University, Beijing, China
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7
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Abstract
Few Type 2 diabetes loci are considered confirmed and replicated across multiple populations. Some genes that have become accepted as contributors to diabetes risk include: calpain 10, peroxisome proliferator-activated receptor-gamma, ATP-sensitive inwardly rectifying potassium channel subunit Kir6.2, hepatocyte nuclear factor 4alpha and hepatic transcription factor 1. While numerous reports of new diabetes loci enter the literature on a regular basis, this review focuses on selected novel associations reported within the last 12 months. In particular, we highlight recent reports of associations between Type 2 diabetes and the transcription factor 7-like 2 gene, associations with micro-opioid receptor and supressor of cytokine signaling 2 genes, and expression and functional analyses of adipokines vaspin and retinol binding protein 4. These new results provide insights into possible mechanisms influencing disease susceptibility and thus new diagnostic and therapeutic opportunities for Type 2 diabetes.
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Affiliation(s)
- Michèle M Sale
- Internal Medicine, Wake Forest University School of Medicine, Center for Human Genomics, Medical Center Blvd, Winston-Salem, NC 27157, USA.
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8
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Schmidt J, Weijdegard B, Mikkelsen AL, Lindenberg S, Nilsson L, Brannstrom M. Differential expression of inflammation-related genes in the ovarian stroma and granulosa cells of PCOS women. Mol Hum Reprod 2013; 20:49-58. [DOI: 10.1093/molehr/gat051] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Tabassum R, Mahajan A, Dwivedi OP, Chauhan G, Spurgeon CJ, Kumar MVK, Ghosh S, Madhu SV, Mathur SK, Chandak GR, Tandon N, Bharadwaj D. Common variants of SLAMF1 and ITLN1 on 1q21 are associated with type 2 diabetes in Indian population. J Hum Genet 2012; 57:184-90. [DOI: 10.1038/jhg.2011.150] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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10
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Hu C, Zhang R, Wang C, Ma X, Wang J, Bao Y, Xiang K, Jia W. Lack of association between genetic polymorphisms within DUSP12 - ATF6 locus and glucose metabolism related traits in a Chinese population. BMC MEDICAL GENETICS 2011; 12:3. [PMID: 21211013 PMCID: PMC3022799 DOI: 10.1186/1471-2350-12-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 01/06/2011] [Indexed: 11/10/2022]
Abstract
Background Genome-wide linkage studies in multiple ethnic populations found chromosome 1q21-q25 was the strongest and most replicable linkage signal in the human chromosome. Studies in Pima Indian, Caucasians and African Americans identified several SNPs in DUSP12 and ATF6, located in chromosome 1q21-q23, were associated with type 2 diabetes. Methods We selected 19 single nucleotide polymorphisms (SNPs) that could tag 98% of the SNPs with minor allele frequencies over 0.1 within DUSP12-ATF6 region. These SNPs were genotyped in a total of 3,700 Chinese Han subjects comprising 1,892 type 2 diabetes patients and 1,808 controls with normal glucose regulation. Results None of the SNPs and haplotypes showed significant association to type 2 diabetes in our samples. No association between the SNPs and quantitative traits was observed either. Conclusions Our data suggests common SNPs within DUSP12-ATF6 locus may not play a major role in glucose metabolism in the Chinese.
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Affiliation(s)
- Cheng Hu
- Department of Endocrinology and Metabolism, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Clinical Center for Diabetes, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, PR China
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11
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Chen XF, Lin WD, Lu SL, Xie T, Ge K, Shi YQ, Zou JJ, Liu ZM, Liao WQ. Mechanistic study of endogenous skin lesions in diabetic rats. Exp Dermatol 2010; 19:1088-95. [DOI: 10.1111/j.1600-0625.2010.01137.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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12
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Lewis JP, Palmer ND, Ellington JB, Divers J, Ng MCY, Lu L, Langefeld CD, Freedman BI, Bowden DW. Analysis of candidate genes on chromosome 20q12-13.1 reveals evidence for BMI mediated association of PREX1 with type 2 diabetes in European Americans. Genomics 2010; 96:211-9. [PMID: 20650312 DOI: 10.1016/j.ygeno.2010.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 07/16/2010] [Accepted: 07/16/2010] [Indexed: 01/02/2023]
Abstract
Chromosome 20q12-q13.1 has been linked to type 2 diabetes (T2D) in multiple populations. We examined the influence of genes in this region on T2D and BMI in two European American case-control populations. SNPs were genotyped in 300 diabetic patients and 310 controls. A subset of 72 SNPs were further genotyped in 470 cases and 442 controls. All genes examined showed evidence of association with T2D in the initial sample (additive P-value [P(a)]=0.00090-0.045). SNPs near PREX1 were also associated in the second case-control population (P(a)=0.017-0.042). The combined analysis resulted in the same SNPs, among others, associated with T2D (P(a)=0.0013-0.041). Stratification analysis by T2D status showed that association with BMI was observed solely in cases (P(a)=0.0018-0.041). Mediation testing revealed that 30-40% of the effects of these SNPs on T2D were significantly mediated by BMI. SNPs near PREX1 may contribute to T2D susceptibility mediated through effects of adiposity in European Americans.
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Affiliation(s)
- Joshua P Lewis
- Center for Human Genomics, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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13
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Hu C, Wang C, Zhang R, Ng MC, Bao Y, Wang C, So WY, Ma RC, Ma X, Chan JC, Xiang K, Jia W. Association of genetic variants of NOS1AP with type 2 diabetes in a Chinese population. Diabetologia 2010; 53:290-8. [PMID: 19937226 DOI: 10.1007/s00125-009-1594-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 10/20/2009] [Indexed: 10/20/2022]
Abstract
AIMS/HYPOTHESIS Chromosome 1q21-q24 has been shown to be linked to type 2 diabetes. The International Type 2 Diabetes 1q Consortium showed that one of the nominal associations was located in the NOS1AP gene. Although this association was not replicated in additional samples of European descent, it remains unknown whether NOS1AP plays a role in Chinese individuals. METHODS In stage 1 analyses, 79 single nucleotide polymorphisms (SNPs) of the NOS1AP gene were successfully genotyped in a group of Shanghai Chinese individuals, comprising 1,691 type 2 diabetes patients and 1,720 control participants. In stage 2 analyses, the SNP showing the strongest association was genotyped in additional Chinese individuals, including 1,663 type 2 diabetes patients and 1,408 control participants. RESULTS In stage 1 analyses, 20 SNPs were nominally associated with type 2 diabetes (p < 0.05), with SNP rs12742393 showing the strongest association (OR 1.24 [95% CI 1.11-1.38]; p = 0.0002, empirical p = 0.019). Haplotype analysis also confirmed the association between rs12742393 and type 2 diabetes. In stage 2 analyses, the difference in allele frequency distribution of rs12742393 did not reach statistical significance (p = 0.254). However, the meta-analysis showed a significant association between rs12742393 and type 2 diabetes with an OR of 1.17 (95% CI 1.07-1.26; p = 0.0005). CONCLUSIONS/INTERPRETATION Our data suggest that NOS1AP variants may not play a dominant role in susceptibility to type 2 diabetes, but a minor effect cannot be excluded.
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Affiliation(s)
- C Hu
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, People's Republic of China
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14
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Bonham CA, Vacratsis PO. Redox regulation of the human dual specificity phosphatase YVH1 through disulfide bond formation. J Biol Chem 2009; 284:22853-64. [PMID: 19567874 DOI: 10.1074/jbc.m109.038612] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
YVH1 was one of the first eukaryotic dual specificity phosphatases cloned, and orthologues poses a unique C-terminal zinc-coordinating domain in addition to a cysteine-based phosphatase domain. Our recent results revealed that human YVH1 (hYVH1) protects cells from oxidative stress. This function requires phosphatase activity and the zinc binding domain. This current study provides evidence that the thiol-rich zinc-coordinating domain may act as a redox sensor to impede the active site cysteine from inactivating oxidation. Furthermore, using differential thiol labeling and mass spectrometry, it was determined that hYVH1 forms intramolecular disulfide bonds at the catalytic cleft as well as within the zinc binding domain to avoid irreversible inactivation during severe oxidative stress. Importantly, zinc ejection is readily reversible and required for hYVH1 activity upon returning to favorable conditions. This inimitable mechanism provides a means for hYVH1 to remain functionally responsive for protecting cells during oxidative stimuli.
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Affiliation(s)
- Christopher A Bonham
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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15
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Wang H, Hays NP, Das SK, Craig RL, Chu WS, Sharma N, Elbein SC. Phenotypic and molecular evaluation of a chromosome 1q region with linkage and association to type 2 diabetes in humans. J Clin Endocrinol Metab 2009; 94:1401-8. [PMID: 19141583 PMCID: PMC2682467 DOI: 10.1210/jc.2008-2132] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 01/07/2009] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Linkage to type 2 diabetes (T2D) is well replicated on chromosome 1q21-q23. Within this region, T2D was associated with common single nucleotide polymorphisms that marked an extended linkage disequilibrium block, including the liver pyruvate kinase gene (PKLR), in several European-derived populations. In this study we sought to determine the molecular basis for the association and the phenotypic consequences of the risk haplotype. RESEARCH DESIGN AND METHODS Genes surrounding PKLR were resequenced in European-American and African-American cases and controls, and association with T2D was tested. Copy number variants (CNVs) were tested for four regions with real-time PCR. Expression of genes in the region was tested in adipose and muscle from nondiabetic subjects with each genotype. Insulin secretion, insulin sensitivity, and hepatic glucose production were tested in nondiabetic individuals with each haplotype combination. RESULTS No coding variant in the region was associated with T2D. CNVs were rare and not associated with T2D. PKLR was not expressed in available tissues, but expression of genes HCN3, CLK2, SCAMP3, and FDPS was not associated with haplotype combinations in adipose or muscle. Haplotype combinations were not associated with insulin secretion or peripheral insulin sensitivity, but homozygous carriers of the risk haplotype had increased hepatic glucose production during hyperinsulinemia. CONCLUSIONS Noncoding variants in the PKLR region likely alter gene expression of one or more genes. Our extensive physiological and molecular studies suggest increased hepatic glucose production and reduced hepatic insulin sensitivity, thus pointing to PKLR itself as the most likely candidate gene in this population.
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Affiliation(s)
- Hua Wang
- Department of Internal Medicine, Division of Endocrinology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
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16
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Abstract
DUSPs (dual-specificity phosphatases) are a heterogeneous group of protein phosphatases that can dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within the one substrate. DUSPs have been implicated as major modulators of critical signalling pathways that are dysregulated in various diseases. DUSPs can be divided into six subgroups on the basis of sequence similarity that include slingshots, PRLs (phosphatases of regenerating liver), Cdc14 phosphatases (Cdc is cell division cycle), PTENs (phosphatase and tensin homologues deleted on chromosome 10), myotubularins, MKPs (mitogen-activated protein kinase phosphatases) and atypical DUSPs. Of these subgroups, a great deal of research has focused on the characterization of the MKPs. As their name suggests, MKPs dephosphorylate MAPK (mitogen-activated protein kinase) proteins ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase) and p38 with specificity distinct from that of individual MKP proteins. Atypical DUSPs are mostly of low-molecular-mass and lack the N-terminal CH2 (Cdc25 homology 2) domain common to MKPs. The discovery of most atypical DUSPs has occurred in the last 6 years, which has initiated a large amount of interest in their role and regulation. In the past, atypical DUSPs have generally been grouped together with the MKPs and characterized for their role in MAPK signalling cascades. Indeed, some have been shown to dephosphorylate MAPKs. The current literature hints at the potential of the atypical DUSPs as important signalling regulators, but is crowded with conflicting reports. The present review provides an overview of the DUSP family before focusing on atypical DUSPs, emerging as a group of proteins with vastly diverse substrate specificity and function.
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The dual-specificity phosphatase hYVH1 interacts with Hsp70 and prevents heat-shock-induced cell death. Biochem J 2009; 418:391-401. [PMID: 18973475 DOI: 10.1042/bj20081484] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
hYVH1 [human orthologue of YVH1 (yeast VH1-related phosphatase)] is an atypical dual-specificity phosphatase that is widely conserved throughout evolution. Deletion studies in yeast have suggested a role for this phosphatase in regulating cell growth. However, the role of the human orthologue is unknown. The present study used MS to identify Hsp70 (heat-shock protein 70) as a novel hYVH1-binding partner. The interaction was confirmed using endogenous co-immunoprecipitation experiments and direct binding of purified proteins. Endogenous Hsp70 and hYVH1 proteins were also found to co-localize specifically to the perinuclear region in response to heat stress. Domain deletion studies revealed that the ATPase effector domain of Hsp70 and the zinc-binding domain of hYVH1 are required for the interaction, indicating that this association is not simply a chaperone-substrate complex. Thermal phosphatase assays revealed hYVH1 activity to be unaffected by heat and only marginally affected by non-reducing conditions, in contrast with the archetypical dual-specificity phosphatase VHR (VH1-related protein). In addition, Hsp70 is capable of increasing the phosphatase activity of hYVH1 towards an exogenous substrate under non-reducing conditions. Furthermore, the expression of hYVH1 repressed cell death induced by heat shock, H2O2 and Fas receptor activation but not cisplatin. Co-expression of hYVH1 with Hsp70 further enhanced cell survival. Meanwhile, expression of a catalytically inactive hYVH1 or a hYVH1 variant that is unable to interact with Hsp70 failed to protect cells from the various stress conditions. The results suggest that hYVH1 is a novel cell survival phosphatase that co-operates with Hsp70 to positively affect cell viability in response to cellular insults.
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Sale MM, Lu L, Spruill IJ, Fernandes JK, Lok KH, Divers J, Langefeld CD, Garvey WT. Genome-wide linkage scan in Gullah-speaking African American families with type 2 diabetes: the Sea Islands Genetic African American Registry (Project SuGAR). Diabetes 2009; 58:260-7. [PMID: 18835935 PMCID: PMC2606883 DOI: 10.2337/db08-0198] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
OBJECTIVE The Gullah-speaking African American population from the Sea Islands of South Carolina is characterized by a low degree of European admixture and high rates of type 2 diabetes and diabetic complications. Affected relative pairs with type 2 diabetes were recruited through the Sea Islands Genetic African American Registry (Project SuGAR). RESEARCH DESIGN AND METHODS We conducted a genome-wide linkage scan, genotyping 5,974 single nucleotide polymorphisms in 471 affected subjects and 50 unaffected relatives from 197 pedigrees. Data were analyzed using a multipoint engine for rapid likelihood inference and ordered subsets analyses (OSAs) for age at type 2 diabetes diagnosis, waist circumference, waist-to-hip ratio, and BMI. We searched for heterogeneity and interactions using a conditional logistic regression likelihood approach. RESULTS Linkage peaks on chromosome 14 at 123-124 cM were detected for type 2 diabetes (logarithm of odds [LOD] 2.10) and for the subset with later age at type 2 diabetes diagnosis (maximum LOD 4.05). Two linkage peaks on chromosome 7 were detected at 44-45 cM for type 2 diabetes (LOD 1.18) and at 78 cM for type 2 diabetes (LOD 1.64) and the subset with earlier age at type 2 diabetes diagnosis (maximum LOD 3.93). The chromosome 14 locus and a peak on 7p at 29.5 cM were identified as important in the multilocus model. Other regions that provided modest evidence for linkage included chromosome 1 at 167.5 cM (LOD 1.51) and chromosome 3 at 121.0 cM (LOD 1.61). CONCLUSIONS This study revealed a novel type 2 diabetes locus in an African American population on 14q that appears to reduce age of disease onset and confirmed two loci on chromosome 7.
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Affiliation(s)
- Michèle M Sale
- Center for Public Health Genomics, University of Virginia, Charlottesville, Virginia, USA.
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Hasstedt SJ, Chu WS, Das SK, Wang H, Elbein SC. Type 2 diabetes susceptibility genes on chromosome 1q21-24. Ann Hum Genet 2008; 72:163-9. [PMID: 18269685 DOI: 10.1111/j.1469-1809.2007.00416.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Type 2 diabetes (T2D) has been linked to chromosome 1q21-24 in multiple samples, including a Utah family sample. Variants in 13 of the numerous candidate genes in the 1q region were tested for association with T2D in a Utah case-control sample. The most promising, 19 variants in 6 candidates, were genotyped on the Utah family sample. Herein, we tested the 19 variants individually and in pairs for an effect on T2D risk in family members using a logistic regression model that accounted for gender, age, and BMI and attributed residual genetic effects to a polygenic component. Seven variants increased risk significantly through 5 pairs of interactions. The significant variant pairs were apolipoprotein A-II (APOA2) rs6413453 interacting with calsequestrin 1 (CASQ1) rs617698, dual specificity phosphatase 12 (DUSP12) rs1503814, and retinoid X receptor gamma (RXRG) rs10918169, a poly-T insertion-deletion polymorphism in liver pyruvate kinase (PKLR) interacting with APOA2 rs12143180, and DUSP12 rs1027702 interacting with RXRG rs10918169. Genotypes of these 5 variant pairs accounted for 25.8% of the genetic variance in T2D in these pedigrees.
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Affiliation(s)
- S J Hasstedt
- Department of Human Genetics, University of Utah, 15 N. 2030 E., Salt Lake City, UT 84112, USA.
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Abstract
Accumulating evidence suggests that endoplasmic reticulum (ER) stress plays a role in the pathogenesis of diabetes, contributing to pancreatic beta-cell loss and insulin resistance. Components of the unfolded protein response (UPR) play a dual role in beta-cells, acting as beneficial regulators under physiological conditions or as triggers of beta-cell dysfunction and apoptosis under situations of chronic stress. Novel findings suggest that "what makes a beta-cell a beta-cell", i.e., its enormous capacity to synthesize and secrete insulin, is also its Achilles heel, rendering it vulnerable to chronic high glucose and fatty acid exposure, agents that contribute to beta-cell failure in type 2 diabetes. In this review, we address the transition from physiology to pathology, namely how and why the physiological UPR evolves to a proapoptotic ER stress response and which defenses are triggered by beta-cells against these challenges. ER stress may also link obesity and insulin resistance in type 2 diabetes. High fat feeding and obesity induce ER stress in liver, which suppresses insulin signaling via c-Jun N-terminal kinase activation. In vitro data suggest that ER stress may also contribute to cytokine-induced beta-cell death. Thus, the cytokines IL-1beta and interferon-gamma, putative mediators of beta-cell loss in type 1 diabetes, induce severe ER stress through, respectively, NO-mediated depletion of ER calcium and inhibition of ER chaperones, thus hampering beta-cell defenses and amplifying the proapoptotic pathways. A better understanding of the pathways regulating ER stress in beta-cells may be instrumental for the design of novel therapies to prevent beta-cell loss in diabetes.
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Affiliation(s)
- Décio L Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Route de Lennik, 808-CP-618, 1070 Brussels, Belgium.
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Elbein SC. Evaluation of polymorphisms known to contribute to risk for diabetes in African and African-American populations. Curr Opin Clin Nutr Metab Care 2007; 10:415-9. [PMID: 17563458 DOI: 10.1097/mco.0b013e3281e2c99a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Populations of direct African ancestry have much greater genetic diversity than do other populations. African-American populations exhibit twice the prevalence of type 2 diabetes as compared with their Caucasian counterparts. African-American populations are likely to have unique genetic susceptibility to type 2 diabetes. This review addresses current knowledge of susceptibility genes that are shared with other groups and those that are unique to populations of African descent. RECENT FINDINGS When compared with the plethora of Caucasian studies, relatively few studies have been conducted in African or African-American populations. The most exciting findings have been family-based linkage studies, which point to multiple regions that may harbor susceptibility genes. Recent work suggests that the major Caucasian locus, TCF7L2, plays a role in some African-based populations, whereas unique factors remain to be confirmed. SUMMARY Although progress has been made in finding the genetic cause of type 2 diabetes in African and African-American populations, at this time no variant can be considered unequivocally confirmed as a diabetes susceptibility locus.
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Affiliation(s)
- Steven C Elbein
- Medicine and Research Services, Central Arkansas Veterans Affairs Healthcare System, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Abstract
The unbiased approach of genome-wide linkage analysis has shown evidence for linkage of type 2 diabetes mellitus to the chromosome 1q21-25 region in at least eight independent studies. More than 26 candidate genes have already been evaluated, but to date none explain the evidence for linkage in this gene-dense region. Considerable data suggest that multiple genes account for this linkage result. The search for these genes is now the focus of an international consortium of groups reporting linkage of type 2 diabetes to this region of chromosome 1q21-q25.
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Affiliation(s)
- Swapan Kumar Das
- John L. McClellan Veterans Hospital, Endocrinology 111J-1/LR, 4301 West 7th Street, Little Rock, AR 72205, USA
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Bibliography. Current world literature. Diabetes and the endocrine pancreas. Curr Opin Endocrinol Diabetes Obes 2007; 14:170-96. [PMID: 17940437 DOI: 10.1097/med.0b013e3280d5f7e9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chu WS, Das SK, Wang H, Chan JC, Deloukas P, Froguel P, Baier LJ, Jia W, McCarthy MI, Ng MC, Damcott C, Shuldiner AR, Zeggini E, Elbein SC. Activating transcription factor 6 (ATF6) sequence polymorphisms in type 2 diabetes and pre-diabetic traits. Diabetes 2007; 56:856-62. [PMID: 17327457 PMCID: PMC2672156 DOI: 10.2337/db06-1305] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Activating transcription factor 6 (ATF6) is located within the region of linkage to type 2 diabetes on chromosome 1q21-q23 and is a key activator of the endoplasmic reticulum stress response. We evaluated 78 single nucleotide polymorphisms (SNPs) spanning >213 kb in 95 people, from which we selected 64 SNPs for evaluation in 191 Caucasian case subjects from Utah and between 165 and 188 control subjects. Six SNPs showed nominal associations with type 2 diabetes (P = 0.001-0.04), including the nonsynonymous SNP rs1058405 (M67V) in exon 3 and rs11579627 in the 3' flanking region. Only rs1159627 remained significant on permutation testing. The associations were not replicated in 353 African-American case subjects and 182 control subjects, nor were ATF6 SNPs associated with altered insulin secretion or insulin sensitivity in nondiabetic Caucasian individuals. No association with type 2 diabetes was found in a subset of 44 SNPs in Caucasian (n = 2,099), Pima Indian (n = 293), and Chinese (n = 287) samples. Allelic expression imbalance was found in transformed lymphocyte cDNA for 3' untranslated region variants, thus suggesting cis-acting regulatory variants. ATF6 does not appear to play a major role in type 2 diabetes, but further work is required to identify the cause of the allelic expression imbalance.
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Affiliation(s)
- Winston S. Chu
- Division of Endocrinology, Department of Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Swapan Kumar Das
- Division of Endocrinology, Department of Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Hua Wang
- Division of Endocrinology, Department of Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
| | - Juliana C. Chan
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Shatin, Hong Kong, Special Administrative Region (SAR), China
| | | | - Philippe Froguel
- Institut de Biologie de Lille, Lille, France
- Faculty of Life Sciences, Imperial College, London, U.K
| | - Leslie J. Baier
- Phoenix Epidemiology and Clinical Research Section, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Arizona
| | - Weiping Jia
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiaotong University No. 6 People’s Hospital, Shanghai, China
| | - Mark I. McCarthy
- Oxford Centre for Diabetes, Endocrinology and Metabolism and Wellcome Trust Centre for Human Genetics, University of Oxford, U.K
| | - Maggie C.Y. Ng
- Department of Medicine and Therapeutics, Chinese University of Hong Kong, Shatin, Hong Kong, Special Administrative Region (SAR), China
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Coleen Damcott
- Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, Maryland
| | - Alan R. Shuldiner
- Division of Endocrinology, Diabetes and Nutrition, University of Maryland School of Medicine, Baltimore, Maryland
| | - Eleftheria Zeggini
- Oxford Centre for Diabetes, Endocrinology and Metabolism and Wellcome Trust Centre for Human Genetics, University of Oxford, U.K
| | - Steven C. Elbein
- Division of Endocrinology, Department of Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
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