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Li X, Lu J, Wang Y, Huo X, Li Z, Zhang S, Li C, Guo M, Du X, Chen Z. Establishment and Characterization of a Newly Established Diabetic Gerbil Line. PLoS One 2016; 11:e0159420. [PMID: 27427908 PMCID: PMC4948894 DOI: 10.1371/journal.pone.0159420] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/01/2016] [Indexed: 01/09/2023] Open
Abstract
Objectives We aimed to selectively breed a spontaneous diabetic gerbil when a sub-line of inbred gerbil showed increased blood glucose levels was found recently. Then we investigated the characteristics including the serum insulin, triglyceride, cholesterol, leptin, adiponectin and explored the underlying molecular mechanism for the diabetic phenotype. Methods The spontaneous diabetic line of gerbils was selectively inbreed the sub-line of gerbil by monitoring blood glucose of each animal. The serum insulin, adiponectin, and leptin levels were tested using an ELISA kit. The expression levels of GLUT4, Akt, leptin, adiponectin, and calpain 10 (CAPN10) were tested by western blot and Quantitative Real-time PCR (qPCR) in liver, skeletal muscle, and white adipose. Results Our results show that the percentages of animals with FPG≥5.2 (mmol/l), PG2h≥6.8 (mmol/l) and both FPG≥5.2 and PG2h≥6.8 (mmol/l) were increased with the number of breeding generations from F0 (21.33%) to F6 (38.46%). These diabetic gerbils exhibited insulin resistance and leptin resistance as well as decreased adiponectin level in the serum. We also observed decreased expression of adiponectin and increased expression of leptin in the skeletal muscle, respectively. Conclusions These results indicate that we have primarily established a spontaneous diabetic gerbil line, and the diabetic phenotypes may have been accounted for by altered expression of leptin and adiponectin.
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Affiliation(s)
- Xiaohong Li
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Jing Lu
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Ying Wang
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Xueyun Huo
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Zhenkun Li
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Shuangyue Zhang
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Changlong Li
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Meng Guo
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
| | - Xiaoyan Du
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
- * E-mail: (ZC); (XD)
| | - Zhenwen Chen
- School of Basic Medical Science, Capital Medical University, Beijing Key Laboratory of Cancer Invasion & Metastasis Research, Beijing 100069, China
- * E-mail: (ZC); (XD)
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Pánico P, Salazar AM, Burns AL, Ostrosky-Wegman P. Role of calpain-10 in the development of diabetes mellitus and its complications. Arch Med Res 2014; 45:103-15. [PMID: 24508288 DOI: 10.1016/j.arcmed.2014.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 01/22/2014] [Indexed: 01/28/2023]
Abstract
Calpain activity has been implicated in several cellular processes such as cell signaling, apoptosis, exocytosis, mitochondrial metabolism and cytoskeletal remodeling. Evidence has indicated that the impairment of calpain expression and the activity of different calpain family members are involved in diverse pathologies. Calpain-10 has been implicated in the development of type 2 diabetes, and polymorphisms in the CAPN10 gene have been associated with an increased risk of developing this disease. The present work focused on the molecular biology of calpain-10, supporting its key participation in glucose metabolism. Current knowledge regarding the role of calpain-10 in the development of type 2 diabetes mellitus and diabetes-related diseases is additionally reviewed.
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Affiliation(s)
- Pablo Pánico
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México, D.F. Mexico
| | - Ana María Salazar
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México, D.F. Mexico
| | - Anna L Burns
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México, D.F. Mexico
| | - Patricia Ostrosky-Wegman
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México, D.F. Mexico.
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3
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Mendoza-Lorenzo P, Salazar AM, Cortes-Arenas E, Saucedo R, Taja-Chayeb L, Flores-Dorantes MT, Pánico P, Sordo M, Ostrosky-Wegman P. The reduction of Calpain-10 expression is associated with risk polymorphisms in obese children. Gene 2013; 516:126-31. [DOI: 10.1016/j.gene.2012.12.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 12/03/2012] [Indexed: 11/17/2022]
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Abstract
Type 2 diabetes mellitus is a complex metabolic disease that is caused by insulin resistance and beta-cell dysfunction. Furthermore, type 2 diabetes has an evident genetic component and represents a polygenic disease. During the last decade, considerable progress was made in the identification of type 2 diabetes risk genes. This was crucially influenced by the development of affordable high-density single nucleotide polymorphism (SNP) arrays that prompted several successful genome-wide association scans in large case-control cohorts. Subsequent to the identification of type 2 diabetes risk SNPs, cohorts thoroughly phenotyped for prediabetic traits with elaborate in vivo methods allowed an initial characterization of the pathomechanisms of these SNPs. Although the underlying molecular mechanisms are still incompletely understood, a surprising result of these pathomechanistic investigations was that most of the risk SNPs affect beta-cell function. This favors a beta-cell-centric view on the genetics of type 2 diabetes. The aim of this review is to summarize the current knowledge about the type 2 diabetes risk genes and their variants' pathomechanisms.
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Affiliation(s)
- Harald Staiger
- Department of Internal Medicine, Division of Endocrinology, Diabetology, Angiology, Nephrology, and Clinical Chemistry, University Hospital Tübingen, D-72076 Tübingen, Germany
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5
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Norton L, Parr T, Chokkalingam K, Bardsley RG, Ye H, Bell GI, Pelsers MMAL, van Loon LJC, Tsintzas K. Calpain-10 gene and protein expression in human skeletal muscle: effect of acute lipid-induced insulin resistance and type 2 diabetes. J Clin Endocrinol Metab 2008; 93:992-8. [PMID: 18089694 PMCID: PMC2729205 DOI: 10.1210/jc.2007-1981] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Our objective was to investigate the effect of lipid-induced insulin resistance and type 2 diabetes on skeletal muscle calpain-10 mRNA and protein levels. RESEARCH DESIGN AND METHODS In the first part of this study, 10 healthy subjects underwent hyperinsulinemic euglycemic (4.5 mmol/liter) clamps for 6 h with iv infusion of either saline or a 20% Intralipid emulsion (Fresenius Kabi AG, Bad Homburg, Germany). Skeletal muscle biopsies were taken before and after 3- and 6-h insulin infusion and analyzed for calpain-10 mRNA and protein expression. In the second part of the study, muscle samples obtained after an overnight fast in 10 long-standing, sedentary type 2 diabetes patients, 10 sedentary, weight-matched, normoglycemic controls, and 10 age-matched, endurance-trained cyclists were analyzed for calpain-10 mRNA and protein content. RESULTS Intralipid infusion in healthy subjects reduced whole body glucose disposal by approximately 50% (P<0.001). Calpain-10 mRNA (P=0.01) but not protein content was reduced after 6-h insulin infusion in both the saline and Intralipid emulsion trials. Skeletal muscle calpain-10 mRNA and protein content did not differ between the type 2 diabetes patients and normoglycemic controls, but there was a strong trend for total calpain-10 protein to be greater in the endurance-trained athletes (P=0.06). CONCLUSIONS These data indicate that skeletal muscle calpain-10 expression is not modified by insulin resistance per se and suggest that hyperinsulinemia and exercise training may modulate human skeletal muscle calpain-10 expression.
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Affiliation(s)
- L Norton
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Nottingham University, Nottingham, NG7 2UH, United Kingdom
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6
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Turner MD. Coordinated control of both insulin secretion and insulin action through calpain-10-mediated regulation of exocytosis? Mol Genet Metab 2007; 91:305-7. [PMID: 17560157 DOI: 10.1016/j.ymgme.2007.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 04/27/2007] [Indexed: 12/31/2022]
Abstract
Calpain-10 was first identified through a genome scan seeking to identify diabetes predisposition genes. Both genetic and functional data has since indicated that calpain-10 has an important role in insulin resistance and intermediate phenotypes, including those associated with adipocytes and skeletal muscle. Evidence presented in this issue by Brown, Yeaman, and Walker utilizes siRNA technology to specifically knock down calpain-10 expression, and suggests that calpain-10 facilitates GLUT4 translocation through effects on the distal secretory pathway. Calpain-10 is also an important molecule in the pancreatic beta-cell, where it has been shown to regulate exocytosis through partial proteolysis of a member of the secretory granule fusion machinery. In addition, calpain-10 has also been implicated in reorganization of the actin cytoskeleton that accompanies both GLUT4 vesicle translocation and insulin secretion. Taken together, these findings provide fresh hope for the development of novel diabetic treatments, utilizing either pharmacological activators that specifically target calpain-10, or through targeted calpain-10 gene therapy. Therapeutic intervention in this way could simultaneously enhance both insulin secretion and insulin action.
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Affiliation(s)
- Mark D Turner
- Centre for Diabetes and Metabolic Medicine, Institute of Cell and Molecular Science, Barts and The London Queen Mary's School of Medicine and Dentistry, University of London, London E1 2AT, United Kingdom.
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Brown AE, Yeaman SJ, Walker M. Targeted suppression of calpain-10 expression impairs insulin-stimulated glucose uptake in cultured primary human skeletal muscle cells. Mol Genet Metab 2007; 91:318-24. [PMID: 17572128 DOI: 10.1016/j.ymgme.2007.05.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 05/01/2007] [Accepted: 05/02/2007] [Indexed: 12/27/2022]
Abstract
Calpain-10 was identified as a novel type 2 diabetes susceptibility gene, although the mechanisms by which it increases susceptibility to type 2 diabetes remain unclear. As skeletal muscle is the principal site of the peripheral insulin resistance for glucose disposal in type 2 diabetes, we investigated whether targeted suppression of calpain-10 expression directly affects insulin action in cultured human skeletal muscle cells. Short interfering RNAs (siRNAs) were employed to specifically suppress CAPN10 gene expression. Suppression was seen at both the transcript and protein level, as assessed by quantitative PCR and Western blotting. Suppression of CAPN10 mRNA expression (75% decrease compared to untransfected myotubes) was associated with a significant decrease (p=0.04) in insulin-stimulated glucose uptake (1.03+/-0.06 [mean+/-SEM]-fold increase over basal) compared to the untransfected myotubes (1.43+/-0.16-fold increase). In contrast, decreased suppression of calpain-10 expression did not affect insulin-stimulated glycogen synthesis nor insulin-stimulated phosphorylation of protein kinase B, a key component of the insulin-signalling pathway. This study confirms that calpain-10 plays a role in insulin-stimulated glucose uptake in human skeletal muscle cells. Suppression of calpain-10 expression did not affect insulin-stimulated glycogen synthesis nor insulin-signalling via PKB, suggesting that calpain-10 may exert a direct regulatory effect upon the glucose uptake mechanism.
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Affiliation(s)
- Audrey E Brown
- School of Clinical Medical Sciences, University of Newcastle upon Tyne, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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8
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López-Orduña E, García-Mena J, García-Macedo R, Stumvoll M, Cruz M. CAPN10 mRNA splicing and decay is not affected by a SNP associated with susceptibility to type 2 diabetes. Biochem Biophys Res Commun 2007; 358:831-6. [PMID: 17511963 DOI: 10.1016/j.bbrc.2007.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Accepted: 05/01/2007] [Indexed: 01/10/2023]
Abstract
The mRNA concentration of CAPN10, a T2D susceptibility gene was measured in white blood cells of T2D and healthy subjects, as well as the transcript half-life in two SNP-43 genotyped human cell lines, to evaluate a possible relationship between this SNP-43 and the transcript half-life. T2D patients with the SNP-43 G-allele had 4.6-fold more CAPN10 transcripts compared to subjects with the A-allele. The mRNA half-life of this transcript in 293T cells (SNP-43 G/G) and Jurkat cells (SNP-43 A/A) was of 8h. We provide evidence that in T2D subjects the G-allele increases the CAPN10 mRNA levels. We propose a defective CAPN10 pre-mRNA processing is responsible for the decreased levels of SNP-43 A-allele transcripts in peripheral white cells of healthy and T2D individuals.
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Affiliation(s)
- Eduardo López-Orduña
- Departamento de Genética y Biología Molecular, Cinvestav-IPN, Apartado Postal 14-740, Mexico DF 07360, Mexico
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Abdollahi MR, Lewis RM, Gaunt TR, Cumming DVE, Rodriguez S, Rose-Zerilli M, Collins AR, Syddall HE, Howell WM, Cooper C, Godfrey KM, Cameron IT, Day INM. Quantitated transcript haplotypes (QTH) of AGTR1, reduced abundance of mRNA haplotypes containing 1166C (rs5186:A>C), and relevance to metabolic syndrome traits. Hum Mutat 2007; 28:365-73. [PMID: 17211857 DOI: 10.1002/humu.20454] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The angiotensin II type 1 receptor (AGTR1) is the main target through which angiotensin II influences cardiovascular tone, cell growth, and fluid and electrolyte balance. AGTR1 polymorphism has been reported to associate with hypertension, myocardial infarction (MI), and metabolic traits. Here we describe a novel approach to quantitation of transcript haplotypes (QTH) of AGTR1. To determine relative allelic expression from haplotypes, within-individual-between-allele ratiometric analyses in placental cDNA were developed for the transcribed SNPs rs5182:C>T (encoding p.L191) and rs5186:A>C (3'-noncoding "A1166C"). Additionally, between-individual comparisons were made using TaqMan assays applied to both homozygous and heterozygous genotypes and haplotypes. In conjunction, linkage disequilibrium (LD) and genomic haplotype associations with metabolic syndrome were examined. There was no significant difference of mRNA level for alleles of rs5182:C>T, but allele and mRNA haplotypes carrying 1166C exhibited reduced abundance. The effect was much greater in CC homozygotes than in heterozygotes. The promoter region was confirmed to be in a separate haplotype block from the AGTR1 3' region containing rs5182:C>T and rs5186:A>C. Metabolic syndrome trait associations were strongest for the 3' block generally and for the C allele of rs5186:A>C specifically. All effects were much more prominent in homozygotes, possibly reflecting interallelic interaction through feedback loops of mRNA regulation. Differential abundance of AGTR1 mRNA haplotypes may mediate clinical phenotypic observations of the AGTR1 genotype.
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Affiliation(s)
- Mohammad R Abdollahi
- Human Genetics Division, Southampton General Hospital, University of Southampton, Southampton, United Kingdom
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10
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Harris F, Biswas S, Singh J, Dennison S, Phoenix DA. Calpains and their multiple roles in diabetes mellitus. Ann N Y Acad Sci 2007; 1084:452-80. [PMID: 17151322 DOI: 10.1196/annals.1372.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes mellitus (T2DM) can lead to death without treatment and it has been predicted that the condition will affect 215 million people worldwide by 2010. T2DM is a multifactorial disorder whose precise genetic causes and biochemical defects have not been fully elucidated, but at both levels, calpains appear to play a role. Positional cloning studies mapped T2DM susceptibility to CAPN10, the gene encoding the intracellular cysteine protease, calpain 10. Further studies have shown a number of noncoding polymorphisms in CAPN10 to be functionally associated with T2DM while the identification of coding polymorphisms, suggested that mutant calpain 10 proteins may also contribute to the disease. Here we review recent studies, which in addition to the latter enzyme, have linked calpain 5, calpain 3, and its splice variants, calpain 2 and calpain 1 to T2DM-related metabolic pathways along with T2DM-associated phenotypes, such as obesity and impaired insulin secretion, and T2DM-related complications, such as epithelial dysfunction and diabetic cataract.
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Affiliation(s)
- Frederick Harris
- Department of Forensic and Investigative Science, University of Central Lancashire, Preston, PR1 2HE, United Kingdom
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11
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Norton L, Parr T, Bardsley RG, Ye H, Tsintzas K. Characterization of GLUT4 and calpain expression in healthy human skeletal muscle during fasting and refeeding. Acta Physiol (Oxf) 2007; 189:233-40. [PMID: 17305703 DOI: 10.1111/j.1748-1716.2006.01639.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AIMS Calpain-10 and calpain-3 and the diabetes ankyrin repeat protein (DARP) have all been linked to insulin resistance and type 2 diabetes. We set out to measure the expression of these genes in human skeletal muscle and relate them to functional measurements of insulin action during fasting (which induces insulin resistance) and refeeding (which reverses it). METHODS Ten healthy male volunteers underwent 48 h of starvation followed by 24 h of high carbohydrate refeeding. On three occasions, before and after starvation and after refeeding, subjects underwent a 16 min insulin tolerance test to quantify insulin sensitivity. Muscle biopsies were obtained before and after fasting and after refeeding for the analysis of calpain-10 and calpain-3, GLUT4 and DARP expression by Western blotting and real-time PCR. RESULTS Fasting led to a marked reduction in whole body insulin sensitivity by approx. 45% (P<0.01) and skeletal muscle GLUT4 gene expression by approx. 40% (P<0.05). However, fasting had no effect on calpain-10 and calpain-3 mRNA or protein levels, or DARP mRNA expression. Refeeding only partly restored insulin sensitivity and GLUT4 gene expression to their pre-fast values, but did not effect the expression of calpain-10, calpain-3 or DARP. CONCLUSIONS These findings demonstrate that in healthy non-diabetic humans induction of insulin resistance by fasting and its reversal by refeeding with a high CHO diet is mirrored by changes in skeletal muscle GLUT4 but not calpain-10 and calpain-3 expression.
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Affiliation(s)
- L Norton
- Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Nottingham University Medical School, Queens Medical Centre, Nottingham, UK
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12
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Abstract
Calpain-10 (CAPN10) is the first diabetes gene to be identified through a genome scan. Many investigators, but not all, have subsequently found associations between CAPN10 polymorphism and type 2 diabetes (T2D) as well as insulin action, insulin secretion, aspects of adipocyte biology and microvascular function. However, this has not always been with the same single nucleotide polymorphism (SNP) or haplotype or the same phenotype, suggesting that there might be more than one disease-associated CAPN10 variant and that these might vary between ethnic groups and the phenotype under study. Our understanding of calpain-10 physiological action has also been greatly augmented by our knowledge of the calpain family domain structure and function, and the relationship between calpain-10 and other calpains is discussed here. Both genetic and functional data indicates that calpain-10 has an important role in insulin resistance and intermediate phenotypes, including those associated with the adipocyte. In this regard, emerging evidence would suggest that calpain-10 facilitates GLUT4 translocation and acts in reorganization of the cytoskeleton. Calpain-10 is also an important molecule in the beta-cell. It is likely to be a determinant of fuel sensing and insulin exocytosis, with actions at the mitochondria and plasma membrane respectively. We postulate that the multiple actions of calpain-10 may relate to its different protein isoforms. In conclusion, the discovery of calpain-10 by a genetic approach has identified it as a molecule of importance to insulin signaling and secretion that may have relevance to the future development of novel therapeutic targets for the treatment of T2D.
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Affiliation(s)
- Mark D Turner
- Centre for Diabetes and Metabolic Medicine, Institute of Cell and Molecular Science, Barts and The London Queen Mary's School of Medicine and Dentistry, University of London, London, E1 2AT United Kingdom.
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13
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Logie LJ, Brown AE, Yeaman SJ, Walker M. Calpain inhibition and insulin action in cultured human muscle cells. Mol Genet Metab 2005; 85:54-60. [PMID: 15862281 DOI: 10.1016/j.ymgme.2005.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 01/04/2005] [Accepted: 01/04/2005] [Indexed: 11/26/2022]
Abstract
Variation in the calpain 10 gene has been reported to increase susceptibility to type 2 diabetes. Part of this susceptibility appears to be mediated by a decrease in whole body insulin sensitivity. As skeletal muscle is the primary tissue site of the peripheral insulin resistance in type 2 diabetes, the aim of this study was to use a human skeletal muscle cell culture system to explore the effects of calpain inhibition on insulin action. Calpain 10 mRNA and protein expression was examined in cultured myoblasts, myotubes, and whole skeletal muscle from non-diabetic subjects using RT-PCR and Western blotting. Changes in insulin-stimulated glucose uptake and glycogen synthesis in response to the calpain inhibitors ALLN and ALLM were measured. Calpain 10 expression was confirmed in cultured human myoblasts, myotubes, and native skeletal muscle. Insulin-stimulated glucose uptake was significantly decreased following preincubation with ALLN [404+/-40 vs 505+/-55 (mean+/-SEM)pmol/mg/min; with vs without ALLN: p = 0.04] and ALLM [455+/-38 vs 550+/-50 pmol/mg/min; with vs without ALLM: p = 0.025] in day 7 fused myotubes, but not in myoblasts. Neither ALLN nor ALLM affected insulin-stimulated glycogen synthesis in myoblasts or myotubes. These studies confirm calpain 10 expression in cultured human muscle cells and support a role for calpains in insulin-stimulated glucose uptake in human skeletal muscle cells that may be relevant to the pathogenesis of the peripheral insulin resistance in type 2 diabetes.
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Affiliation(s)
- L J Logie
- School of Clinical Medical Sciences, University of Newcastle upon Tyne, Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
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14
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Hillman RT, Green RE, Brenner SE. An unappreciated role for RNA surveillance. Genome Biol 2004; 5:R8. [PMID: 14759258 PMCID: PMC395752 DOI: 10.1186/gb-2004-5-2-r8] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 12/05/2003] [Accepted: 01/02/2004] [Indexed: 12/27/2022] Open
Abstract
Following the hypothesis that the public databases contain cloned mRNAs that would be degraded in vivo by the nonsense-mediated mRNA decay mechanism, 144 isoform sequences deposited in SWISS-PROT have been identified that derive from mRNAs with premature termination codons
Background Nonsense-mediated mRNA decay (NMD) is a eukaryotic mRNA surveillance mechanism that detects and degrades mRNAs with premature termination codons (PTC+ mRNAs). In mammals, a termination codon is recognized as premature if it lies more than about 50 nucleotides upstream of the final intron position. More than a third of reliably inferred alternative splicing events in humans have been shown to result in PTC+ mRNA isoforms. As the mechanistic details of NMD have only recently been elucidated, we hypothesized that many PTC+ isoforms may have been cloned, characterized and deposited in the public databases, even though they would be targeted for degradation in vivo. Results We analyzed the human alternative protein isoforms described in the SWISS-PROT database and found that 144 (5.8% of 2,483) isoform sequences amenable to analysis, from 107 (7.9% of 1,363) SWISS-PROT entries, derive from PTC+ mRNA. Conclusions For several of the PTC+ isoforms we identified, existing experimental evidence can be reinterpreted and is consistent with the action of NMD to degrade the transcripts. Several genes with mRNA isoforms that we identified as PTC+ - calpain-10, the CDC-like kinases (CLKs) and LARD - show how previous experimental results may be understood in light of NMD.
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Affiliation(s)
- R Tyler Hillman
- Department of Bioengineering, University of California, Berkeley, CA 94720-3102, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Richard E Green
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Steven E Brenner
- Department of Bioengineering, University of California, Berkeley, CA 94720-3102, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3102, USA
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Ilian MA, Bekhit AEDA, Bickerstaffe R. Does the newly discovered calpain 10 play a role in meat tenderization during post-mortem storage? Meat Sci 2004; 66:317-27. [DOI: 10.1016/s0309-1740(03)00106-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2002] [Revised: 04/22/2003] [Accepted: 04/22/2003] [Indexed: 11/16/2022]
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16
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Paul DS, Harmon AW, Winston CP, Patel YM. Calpain facilitates GLUT4 vesicle translocation during insulin-stimulated glucose uptake in adipocytes. Biochem J 2003; 376:625-32. [PMID: 12974673 PMCID: PMC1223814 DOI: 10.1042/bj20030681] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2003] [Revised: 09/08/2003] [Accepted: 09/16/2003] [Indexed: 12/16/2022]
Abstract
Calpains are a family of non-lysosomal cysteine proteases. Recent studies have identified a member of the calpain family of proteases, calpain 10, as a putative diabetes-susceptibility gene that may be involved in the development of type 2 diabetes. Inhibition of calpain activity has been shown to reduce insulin-stimulated glucose uptake in isolated rat-muscle strips and adipocytes. In this report, we examine the mechanism by which calpain affects insulin-stimulated glucose uptake in 3T3-L1 adipocytes. Inhibition of calpain activity resulted in approx. a 60% decrease in insulin-stimulated glucose uptake. Furthermore, inhibition of calpain activity prevented the translocation of insulin-responsive glucose transporter 4 (GLUT4) vesicles to the plasma membrane, as demonstrated by fluorescent microscopy of whole cells and isolated plasma membranes; it did not, however, alter the total GLUT4 protein content. While inhibition of calpain did not affect the insulin-mediated proximal steps of the phosphoinositide 3-kinase pathway, it did prevent the insulin-stimulated cortical actin reorganization required for GLUT4 translocation. Specific inhibition of calpain 10 by antisense expression reduced insulin-stimulated GLUT4 translocation and actin reorganization. Based on these findings, we propose a role for calpain in the actin reorganization required for insulin-stimulated GLUT4 translocation to the plasma membrane in 3T3-L1 adipocytes. These studies identify calpain as a novel factor involved in GLUT4 vesicle trafficking and suggest a link between calpain activity and the development of type 2 diabetes.
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Affiliation(s)
- David S Paul
- Department of Nutrition, University of North Carolina School of Public Health, 2216A McGavran-Greenberg, Chapel Hill, NC 27599, USA
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Abstract
The calpain system originally comprised three molecules: two Ca2+-dependent proteases, mu-calpain and m-calpain, and a third polypeptide, calpastatin, whose only known function is to inhibit the two calpains. Both mu- and m-calpain are heterodimers containing an identical 28-kDa subunit and an 80-kDa subunit that shares 55-65% sequence homology between the two proteases. The crystallographic structure of m-calpain reveals six "domains" in the 80-kDa subunit: 1). a 19-amino acid NH2-terminal sequence; 2). and 3). two domains that constitute the active site, IIa and IIb; 4). domain III; 5). an 18-amino acid extended sequence linking domain III to domain IV; and 6). domain IV, which resembles the penta EF-hand family of polypeptides. The single calpastatin gene can produce eight or more calpastatin polypeptides ranging from 17 to 85 kDa by use of different promoters and alternative splicing events. The physiological significance of these different calpastatins is unclear, although all bind to three different places on the calpain molecule; binding to at least two of the sites is Ca2+ dependent. Since 1989, cDNA cloning has identified 12 additional mRNAs in mammals that encode polypeptides homologous to domains IIa and IIb of the 80-kDa subunit of mu- and m-calpain, and calpain-like mRNAs have been identified in other organisms. The molecules encoded by these mRNAs have not been isolated, so little is known about their properties. How calpain activity is regulated in cells is still unclear, but the calpains ostensibly participate in a variety of cellular processes including remodeling of cytoskeletal/membrane attachments, different signal transduction pathways, and apoptosis. Deregulated calpain activity following loss of Ca2+ homeostasis results in tissue damage in response to events such as myocardial infarcts, stroke, and brain trauma.
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Affiliation(s)
- Darrell E Goll
- Muscle Biology Group, University of Arizona, Tucson, AZ 85721, USA.
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19
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Hoffstedt J, Näslund E, Arner P. Calpain-10 gene polymorphism is associated with reduced beta(3)-adrenoceptor function in human fat cells. J Clin Endocrinol Metab 2002; 87:3362-7. [PMID: 12107250 DOI: 10.1210/jcem.87.7.8680] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Polymorphism in the calpain-10 gene is linked to type 2 diabetes, insulin resistance, and decreased thermogenesis. In view of the role of beta-adrenoceptors in thermogenesis we investigated the relationship between beta(1)-, beta(2)-, and beta(3)-adrenoceptor-stimulated lipolysis in abdominal sc fat cells and 3 different previously described single nucleotide polymorphisms (SNPs) in the calpain-10 gene (SNP-19, SNP-43, and SNP-63). The study sample comprised 240 healthy subjects. A strong association between lipolytic beta(3)-receptor function in adipocytes and the SNP-19, which is a deletion/insertion (1/2) was observed in overweight subjects (body mass index, >25 kg/m(2)), but not in lean ones. No association was found between any of the polymorphisms and lipolytic function of either beta(1)- or beta(2)-receptors. Carriers of 1/1 in SNP-19 had 30-fold decreased lipolytic sensitivity of beta(3)-adrenoceptors in comparison to 1/2 or 2/2 carriers (P = 0.0019, by ANOVA). This was found in both genders and was not influenced by SNP-43 or SNP-63 in the calpain-10 gene or by the Trp(64)Arg polymorphism in the beta(3)-adrenoceptor gene. In conclusion, a deletion/insertion polymorphism in the calpain-10 gene (SNP-19) is associated with reduced beta(3)-adrenoceptor function in obesity. This could be of importance for regulating thermogenesis in overweight subjects.
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Affiliation(s)
- Johan Hoffstedt
- Department of Medicine, Huddinge University Hospital, Karolinska Institute, SE-141 86 Stockholm, Sweden
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Abstract
Positional cloning studies conducted on a region of chromosome 2q providing evidence for linkage to type 2 diabetes implicated genetic variation at the calpain-10 gene (CAPN10) in susceptibility to type 2 diabetes. The variants identified in these studies are located in introns, rather than in coding sequence. It was proposed that the cumulative effects of a combination of variants, rather than variation at a single site, increase the risk of type 2 diabetes. Confirmation of the hypothesis that non-coding sequence variation in CAPN10 affects susceptibility to type 2 diabetes has implications for how we search for susceptibility variants and interpret results of positional cloning studies for complex disorders, and suggests a new pathway in glucose homeostasis. We review the results of follow-up studies on the CAPN10 finding, and consider the issues inherent in conclusively establishing that particular genetic variation affects a complex phenotype.
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Affiliation(s)
- Nancy J Cox
- University of Chicago, Department of Human Genetics, 507H CLSC, 920 E. 58th Street, Chicago, IL 60637, USA.
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Ehrmann DA, Schwarz PEH, Hara M, Tang X, Horikawa Y, Imperial J, Bell GI, Cox NJ. Relationship of calpain-10 genotype to phenotypic features of polycystic ovary syndrome. J Clin Endocrinol Metab 2002; 87:1669-73. [PMID: 11932299 DOI: 10.1210/jcem.87.4.8385] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Polycystic ovary syndrome (PCOS) is associated with an increased risk of impaired glucose tolerance and type 2 diabetes. Recent evidence suggests that variation in the gene encoding the cysteine protease calpain-10 influences susceptibility to type 2 diabetes. The present study was undertaken to determine whether variation in this gene is associated with quantitative traits pertinent to the pathogenesis of PCOS and diabetes. We studied 212 women with PCOS (124 white of European ancestry, 57 African-American, 13 Hispanic, 13 Asian-American, and 5 Middle-Eastern). Each subject was genotyped for 3 DNA polymorphisms in the calpain-10 gene associated with type 2 diabetes (SNP-43, -19, and -63). The white and African-American subjects were examined for association of these polymorphisms with phenotypic features of PCOS and type 2 diabetes. There were not enough individuals in the other groups for similar genotype/phenotype analyses. Nineteen (9%) of the 212 women with PCOS were diabetic and were not included in the genotype/phenotype analyses. Twelve (63%) of these subjects were African-American. Phenotypic traits in nondiabetic white probands did not differ whether analyzed for each individual SNP (SNP-43, -19, -63) or haplotype combination. Nor was there association of SNP-43, -19, or -63 with any of the phenotypic features of type 2 diabetes or PCOS in nondiabetic African-Americans. However, nondiabetic African-Americans with the 112/121-haplotype combination had significantly higher insulin levels, in response to an oral glucose challenge, as reflected in the area under the insulin curve (257,021 +/- 95,384 vs. 136,240 +/- 11,468 pmol/min; P = 0.03), compared with those with other haplotypes. This finding was particularly notable because the 112/121 subjects were less obese. The difference between groups in area under the insulin response curve remained significant (P = 0.002 by analysis of covariance) after adjustment for body mass index. In addition to its association with insulin levels in African-Americans, the 112/121-haplotype combination was associated with an approximate 2-fold increase in risk of PCOS in both African-Americans and whites.
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Affiliation(s)
- David A Ehrmann
- Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA.
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Escobar-Morreale HF, Peral B, Villuendas G, Calvo RM, Sancho J, San Millán JL. Common single nucleotide polymorphisms in intron 3 of the calpain-10 gene influence hirsutism. Fertil Steril 2002; 77:581-7. [PMID: 11872216 DOI: 10.1016/s0015-0282(01)03206-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To study three common polymorphisms in intron 3 of the calpain-10 gene (CAPN10) in hyperandrogenic patients. DESIGN Case-control study. SETTING Academic hospital. PATIENT(S) Ninety-seven hyperandrogenic patients and 37 healthy controls. INTERVENTION(S) Basal and adrenocorticotropin-stimulated serum samples and genomic DNA samples were obtained during the follicular phase of the menstrual cycle. MAIN OUTCOME MEASURE(S) Genotyping of the UCSNP43, UCSNP44, and UCSNP45 polymorphisms in CAPN10 and serum androgen levels. RESULT(S) Sixteen patients had idiopathic hirsutism, defined as normal serum androgen levels and regular menstrual cycles. Eighty-one hyperandrogenic patients (those presenting with hyperandrogenemic hirsutism or the polycystic ovary syndrome) were analyzed further. UCSNP45 alleles were distributed differently among the study groups. Heterozygosity for the uncommon C allele was increased in patients with idiopathic hirsutism (31.3%) and reduced in hyperandrogenic patients (7.4%) compared with controls (16.2%). The UCSNP44 and UCSNP43 alleles were in linkage disequilibrium, and were distributed equally among patients with idiopathic hirsutism, hyperandrogenism, and controls. However, the uncommon A allele at UCSNP43 was associated with higher hirsutism score (mean [+/- SD], 9.9 +/- 6.8, 12.7 +/- 7.7, and 14.6 +/- 8.2 in GG, GA, and AA participants, respectively). No other differences were observed in clinical and biochemical characteristics, including insulin sensitivity, by CAPN10 variant. CONCLUSION(S) The C allele at the UCSNP45 locus in CAPN10 is associated with idiopathic hirsutism, and UCSNP43 influences the hirsutism score.
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Sun L, Cox NJ, McPeek MS. A statistical method for identification of polymorphisms that explain a linkage result. Am J Hum Genet 2002; 70:399-411. [PMID: 11791210 PMCID: PMC526471 DOI: 10.1086/338660] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Accepted: 11/13/2001] [Indexed: 01/16/2023] Open
Abstract
Suppose that many polymorphic sites have been identified and genotyped in a region showing strong linkage with a trait. A key question of interest is which site (or combination of sites) in the region influences susceptibility to the trait. We have developed a novel statistical approach to this problem, in the context of qualitative-trait mapping, in which we use linkage data to identify the polymorphic sites whose genotypes could fully explain the observed linkage to the region. The information provided by this analysis is different from that provided by tests of either linkage or association. Our approach is based on the observation that if a particular site is the only site in the region that influences the trait, then-conditional on the genotypes at that site for the affected relatives-there should be no unexplained oversharing in the region among affected individuals. We focus on the affected sib-pair study design and develop test statistics that are variations on the usual allele-sharing methods used in linkage studies. We perform hypothesis tests and derive a confidence set for the true causal polymorphic site, under the assumption that there is only one site in the region influencing the trait. Our method is appropriate under a very general model for how the site influences the trait, including epistasis with unlinked loci, correlated environmental effects within families, and gene-environment interaction. We extend our method to larger sibships and apply it to an NIDDM1 data set.
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Affiliation(s)
- Lei Sun
- Departments of Statistics, Human Genetics, and Medicine, University of Chicago, Chicago
| | - Nancy J. Cox
- Departments of Statistics, Human Genetics, and Medicine, University of Chicago, Chicago
| | - Mary Sara McPeek
- Departments of Statistics, Human Genetics, and Medicine, University of Chicago, Chicago
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Abstract
Type 2 diabetes refers to a group of disparate metabolic diseases, which are typically characterized by insulin resistance in peripheral tissues, together with impaired insulin secretion from pancreatic beta-cells. The complexity of type 2 diabetes is related to factors such as genetic heterogeneity, interactions between genes, and the modulating role played by the environment. Recent progress has included defining the molecular basis of monogenic forms of type 2 diabetes, such as familial partial lipodystrophy and the subtypes of maturity-onset diabetes of the young (MODY), and also the identification of chromosomal regions that may harbor type 2 diabetes susceptibility genes. Many common variants in functional and positional candidate genes, including ADRB3, PPARG, ENPP1, and CAPN10, have also been studied for their possible role as determinants of type 2 diabetes, with varying levels of agreement between studies. The availability of a relatively complete sequence of the human genome will increase the amount of genetic information that can be used to evaluate hypotheses for the genetic basis of type 2 diabetes. To make sense of human type 2 diabetes in the post-genomic era, it is essential to have well-defined phenotypes in addition to sufficient numbers of individuals with the appropriate pedigree structure from families and/or communities.
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Affiliation(s)
- C P Busch
- John P. Robarts Research Institute, London, Ontario, Canada N6A 5K8
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