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Amaç: Kalpain-10 (CAPN10), Ca+2 bağımlı intrasellüler sistein proteazlar ailesinin atipik bir üyesidir. Birçok dokuda eksprese edilir ve başta insülin sekresyonu ve aktivitesi olmak üzere çok çeşitli hücresel fonksiyonlar için gereklidir. Tanımlanan ilk Tip 2 diyabet (T2D) yatkınlık genidir. Çalışmamızda bir Türk popülasyonunda CAPN10 gen polimorfizmleri (SNP-44, -43 ve -137) ile artmış T2D riski arasındaki ilişkinin analiz edilmesi amaçlandı. Gereç ve Yöntem: Çalışmaya 149 T2D’li hasta ve 48 sağlıklı birey dahil edildi. Genotiplendirme PCR-SSCP tekniği kullanılarak yapıldı, dizi analizi ile doğrulandı. CAPN10 genotiopleri ile T2D gelişimi ve klinik özellikler arasındaki ilişki istatistiksel olarak analiz edildi. Bulgular: Hastalıkla genotip arasındaki ilişkiyi belirlemek için yapılan odds analizi sonuçlarına göre; SNP-44 ile hastalık arasında ilişki gözlenmezken (OR: 1.417 CI:0.452-4.436, P=0.740), SNP-43 ile hastalık arasında anlamlı ilişki bulundu (OR: 0.455 CI:0.235-0.881, P=0.028). SNP-137 genotip dağılımı bakımından tüm hasta ve kontrol bireylerde C/C olarak tespit edildi. Taranan SNP’ler ile klinik parametreler arasında herhangi bir ilişki bulunmadı (P>0.05). Sonuç: Sonuçlarımıza göre; CAPN10 genindeki SNP-43, Türk populasyonunda T2D gelişimi açısından bir risk faktörüdür.

Objective: Calpain-10 (CAPN10) is an atypical member of the Ca2+ dependent intracellular cysteine proteases family. It is expressed in many tissues and is essential for multiple cellular functions such as insulin secretion and activity. It is the first type 2 diabetes susceptibility gene identified. In our study, we aimed to analyze the relationship between CAPN10 gene polymorphisms (SNP-44, -43 and -137) and increased type 2 diabetes risk in a Turkish population. Material and Methods: 149 T2D patients and 48 healthy individuals were included in the study. Genotyping was performed using the PCR-SSCP technique, confirmed by DNA sequence analysis. The association between CAPN10 genotypes and T2D development and clinical features was statistically analyzed. Results: According to the results of the odds analysis, while no correlation was observed between SNP-44 and disease (OR: 1.417 CI: 0.452-4.436, P=0.740), a significant correlation was found between SNP-43 and disease (OR: 0.455 CI: 0.235-0.881, P=0.028). SNP-137 genotype distribution was detected as C/C in all patient and control individuals. No correlation was found between the scanned SNPs and clinical parameters (P>0.05). Conclusion: According to our results; SNP-43 in the CAPN10 gene is a risk factor for the development of T2D in the Turkish population. [ABSTRACT FROM AUTHOR]

The calpain-10 (CAPN10) protease is implicated in the translocation of the glucose transporter 4 (GLUT4), which is retained in the Golgi matrix vi a the Tether containing a UBX domain for GLUT4 (TUG) protein. Insulin stimulation induces the proteolytic processing of TUG, which leads to the translocation of GLUT4 to the cell membrane. We tested whether TUG is a CAPN10 substrate. Proteolysis of TUG by calpains was assessed using a cell-free system containing calpain-1 and TUG. In situ proteolysis of TUG by calpains was demonstrated in 3T3-L1 adipocytes in the presence of insulin or calpain inhibitors to modulate calpain activity. Proteolysis of TUG by CAPN10 was confirmed using transient or stable silencing of CAPN10 in 3T3-L1 adipocytes. Calpains proteolyzed the C-terminus of TUG in vitro. In adipocytes, insulin-induced cleavage of TUG was correlated with the activation of calpains. Treatment with calpain inhibitors reduced TUG cleavage, resulting in impaired GLUT4 translocation without altering Akt phosphorylation. Furthermore, CAPN10 but not calpain-1 or calpain-2 colocalized with GLUT4 in the absence of insulin, and their colocalization was reduced after stimulation with insulin. Finally, we demonstrated that CAPN10 knockdown reduced the proteolysis of TUG without altering the phosphorylation of Akt or the expression of the Usp25m protease. Thus, our results provide evidence that the TUG protein is clea ved by CAPN10 to regulate GLUT4 translocation. [ABSTRACT FROM AUTHOR]

CAPN10 gene is associated with type 2 diabetes (T2D). Specific members of the calpain system (CAPN1, CAPN2 and CAPN10) are implicated in glucose metabolism. The aim of this study was to evaluate the calpain activity in leukocytes of control subjects and patients with T2D and its association with the calpain family members involved in glucose metabolism and with biochemical parameters that are altered in T2D. Calpain activity under extracellular glucose concentrations (70–280 mg/dL) was evaluated in leukocytes from subjects with and without T2D. Protein and mRNA levels of CAPN1, CAPN2 and CAPN10 were evaluated. Calpain inhibitors assays were performed in leukocytes from subjects without T2D to evaluate glucose uptake. Calpain activity at 100 mg/dL glucose was correlated with biochemical parameters by multivariate regression. Calpain activity in control subjects increased with extracellular glucose concentration in a dose-dependent manner, showing a negative association with HbA1c levels and total amount of CAPN10 protein. In contrast, calpain activity is decreased in patients with T2D and do not respond to changes in glucose concentration. A reduction of CAPN1 autolytic fragments were observed in the subjects with diabetes. Calpain inhibitors decreased calpain activity but did not altered glucose uptake in leukocytes. Calpain activity induced by glucose in leukocytes was associated with biochemical markers of glucose metabolism and with CAPN10 protein abundance. Calpain activity is low in subjects with T2D. Thus, calpain activity induced by extracellular glucose in leukocytes could be a potential marker for T2D early risk detection. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the meta-analysis is to evaluate the association between calpain-10 (CANP10) gene polymorphisms and gestational diabetes mellitus (GDM).Methods: A computer-based retrieval was performed in Web of Science, Embase and PubMed databases for eligible studies. The genotype data from four variants in CANP10 [single-nucleotide polymorphisms (SNP) 19, 43, 44, and 63] were collected. The pooled Odds ratios (ORs) with 95 % confidence intervals (CI) were conducted for five genetic models.Results: Five studies containing 1003 GDMs and 1788 controls are included in this meta-analysis. The overall combined odds ratios show that SNP 19 and SNP 43 are not associated with increased risk of GDM in all genetic models. The association between SNP 63 and GDM is only significant in the heterozygous model (OR 2.79, 95 % CI 1.15-6.74). The SNP 44 is associated with increased risk of GDM in the recessive model (OR 1.75, 95 % CI 1.07-2.85), but only two studies are included.Conclusions: This meta-analysis indicates that women carriage of TT genotype in SNP 63 (rs5030952) is associated with increased risk in GDM. [ABSTRACT FROM AUTHOR]

Introduction: Diabetes Mellitus (DM) type 2 is a common pathology with multifactorial etiology, which exact genetic bases remain unknown. Some studies suggest that single nucleotides polymorphisms (SNPs) in the CAPN10 gene (Locus 2q37.3) could be associated with the development of this disease, including the insertion/deletion polymorphism SNP-19 (2R→3R).Objective: The present study determined the association between the SNP-19 and the risk of developing DM type 2 in Ciudad Juarez population. Methodology: For this study 107 participants were selected: 43 diabetics type 2 (cases) and 64 non diabetics with no family history of DM type 2 in first grade (control). Anthropometric studies were realized as well as lipids, lipoproteins and serum glucose biochemical profiles. The genotypification of SNP-19 was performed using peripheral blood lymphocytes DNA, polymerase chain reactions (PCR), and electrophoretic analysis in agarose gels. Once obtained the genotypic and allelic frequencies, the Hardy-Weinberg equilibrium test (GenAlEx 6.4) was also performed. Results: Using the X2 analysis it was identified the genotypic differences between cases and control with higher frequency of the homozygous genotype 3R of SNP-19 in the cases group (0.418) compared to control group (0.265). Also, it was observed an association between genotype 2R/3R with elevated weight, body mass index, and waist and hip circumferences, but only in the diabetic group (P=< 0.05).Conclusion: The findings in this study suggest thatSNP-19 in CAPNIO may participate in the development of DM type 2 in the studied population. [ABSTRACT FROM AUTHOR]

Overexpression of human epithelial growth factor receptor 2 (HER2) is a poor prognostic factor in breast cancer. HER2 is a transmembrane receptor comprising an extracellular domain (ECD), a single transmembrane domain, and an intracellular domain (ICD) with tyrosine-kinase activity. Receptor dimerization triggers pivotal effector pathways in cancer, such as phosphatidylinositol 3-kinase (PI3K) signaling. Currently, screening of HER2 in breast tumors for prognostic and therapeutic purposes involves immunohistochemical (IHC) phenotyping for the ECD, in which tumors with IHC scores below 2+ are reported as HER2-negative. We used a label-free liquid chromatography–mass spectrometry (LC–MS) proteomic approach to compare plasma samples from patients with HER2-positive breast tumors and patients with HER2-negative tumors. Patients with HER2-negative tumors expressed higher circulating levels of calpain-10 than patients with HER2-positive tumors. Calpains cleave HER2, releasing its ECD and transforming phenotypically positive tumors into phenotypically negative tumors. Therefore, we investigated the expression of the ICD in HER2-negative samples that overexpressed calpain-10. We found that 16% of HER2-negative tumors were positive for HER2-ICD, which was associated with circulating HER2-ECD. HER2 gene amplification was also observed in some HER2-negative tumors. Positive staining for the PI3K pathway was observed in the HER2-negative, ICD-positive tumors, similar to the HER2-positive cohort. Microarray analysis revealed that HER2-negative, ICD-positive samples clustered between HER2-positive tumors and triple-negative tumors. Survival analysis revealed that outcome in women with HER2-negative, ICD-positive tumors was better than in women bearing HER2-negative, ICD-negative (triple negative) tumors but was quite similar to HER2-positive tumors and worse than women with luminal A tumors. Moreover, in vitro analyses revealed that MDA-MB 231, a triple negative cell line, possesses calpain-10 and HER2-p-ICD up-regulation and blockage of calpain-10 activity promoted an increase in HER2-p-ICD and p-AKT levels, suggesting an increase in these pathways signaling. These data indicate that HER2-negative tumors with HER2-ICD positivity exhibit clinical behavior closer to that of HER2-positive tumors. This indicates a need for HER2-ICD screening when determining the molecular profile of breast tumors. These findings further indicate that lapatinib should be investigated as a target therapy for HER2-ICD-positive breast tumors. [ABSTRACT FROM AUTHOR]

Dyslipidemia is a major public health problem, and therefore, it is important to develop dietary strategies to diminish the prevalence of this disorder. It was recently reported that diet may play an important role in triggering insulin resistance by interacting with genetic variants at the CAPN10 gene locus in patients with metabolic syndrome. Nonetheless, it remains unknown whether genetic variants of genes involved in the development of type 2 diabetes are associated with variations in high-density lipoprotein cholesterol (HDL-C). The study used a single-center, prospective, cohort design. Here, we assessed the effect of four variants of the CAPN1O gene on HDL-C levels in response to a soy protein and soluble fiber dietary portfolio in subjects with dyslipidemia. In 31 Mexican dyslipidemic individuals, we analyzed four CAPN10 gene variants (rs5030952, rs2975762, rs3792267, and rs2975760) associated with type 2 diabetes. Subjects with the GG genotype of the rs2975762 variant of the CAPN10 gene were better responders to dietary intervention, showing increased HDL-C concentrations from the first month of treatment. HDL-C concentrations in participants with the wild type genotype increased by 17.0%, whereas the HDL-C concentration in subjects with the variant genotypes increased by only 3.22% (p = 0.03); the low-density lipoprotein cholesterol levels of GG carriers tended to decrease (-12.6%). These results indicate that Mexican dyslipidemic carriers of the rs2975762-GG genotype are better responders to this dietary intervention. [ABSTRACT FROM AUTHOR]

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. [Copyright &y& Elsevier]

Background. In several large studies an association between certain single-nucleotide polymorphisms (SNP) of the calpain-10 gene (CAPN10) with type 2 diabetes mellitus (T2D) has been identified. Since T2D and gestational diabetes mellitus (GDM) seem to be linked pathophysiologically, we examined the frequencies of CAPN10-polymorphisms in women with GDM. Methods. By using real-time PCR assisted melting curve analysis samples of 204 women with GDM and 297 controls were tested for variations of SNP-43, -44, -63 and Indel-19 of CAPN10. Results. Since the genotype frequencies found in SNP-44 among the controls did not meet the Hardy-Weinberg-Equilibrium, the further analysis was performed with SNP-43, -63 and Indel-19 only. Herein, the distribution of neither genotype nor allele nor haplogenotype-combination nor haplotype showed a significant difference between both groups. Conclusions. Variations of SNP-43, -63 and Indel-19 of CAPN10 were not associated with an increased risk of developing GDM. [ABSTRACT FROM AUTHOR]

Aims Calcium dyshomeostasis is implicated in the pathogenesis of several neurodegenerative disorders including Alzheimer's disease. However, much of the previous research has focused on changes in neuronal calcium signalling. In a recent microarray study we identified dysregulation of several key signalling pathways including the Ca2+ signalling pathway in astrocytes as Alzheimer-type pathology developed. In this study we sought to determine the expression of calpain-10 and calcium/calmodulin-dependent kinase alpha ( CamKIIα) in relation to Alzheimer-type pathology in a population-based study. Methods Using post mortem temporal cortex samples derived from the Medical Research Council Cognitive Function and Ageing Study ( MRC- CFAS) ageing brain cohort we examined calpain-10 and CamKIIα gene and protein expression using quantitative polymerase chain reaction and immunohistochemistry. Results We demonstrate that astrocytic expression of calpain-10 is up-regulated, and CamKIIα down-regulated with increasing Braak stage. Using immunohistochemistry we confirm protein expression of calpain-10 in astrocytes throughout the temporal cortex and demonstrate that calpain-10 immunoreactivity is correlated with both local and global measures of Alzheimer-type pathology. In addition, we identify a subpopulation of calpain-10 immunoreactive interlaminar astrocytes that extend processes deep into the cortex. CamKIIα is predominantly neuronal in localization and is associated with the presence of diffuse plaques in the ageing brain. Discussion Dysregulated expression of key calcium signalling molecules occurs with progression of Alzheimer-type pathology in the ageing brain, highlighting the need for further functional studies of astrocytic calcium signalling with respect to disease progression. [ABSTRACT FROM AUTHOR]

Abstract: Recent evidences suggest that common functional polymorphisms in the promoter region of the Calpain-10 gene may have an impact on an individual's susceptibility to polycystic ovary syndrome (PCOS), but individually published results are inconclusive. Our meta-analysis is aimed to provide a more precise estimation of the relationships between Calpain-10 genetic polymorphisms and PCOS risk. An extensive literature search for relevant studies was conducted on PubMed, Embase, Web of Science, Cochrane Library, and CBM databases from inception through April 1st, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratio (OR) with 95% confidence interval (CI) was calculated. Fourteen case–control studies were included with a total of 2123 PCOS patients and 3612 healthy controls. Nine common SNPs in the Calpain-10 gene were addressed. Our meta-analysis indicated that UCSNP-19, UCSNP-63 and UCSNP-45 polymorphisms in the Calpain-10 gene might be associated with increased PCOS risk. However, no statistically significant association was observed in UCSNP-43, UCSNP-22, UCSNP-43, UCSNP-45, UCSNP-56, UCSNP-58, and UCSNP-110 polymorphisms. Further subgroup analysis by ethnicity revealed that UCSNP-19, UCSNP-63 and UCSNP-45 polymorphisms might decrease the risk of PCOS among Asian populations, but not among Caucasian populations. The current meta-analysis indicates that UCSNP-19, UCSNP-63 and UCSNP-45 polymorphisms in the Calpain-10 gene may be risk factors for PCOS, especially among Asian populations. [Copyright &y& Elsevier]

Calpain-10 (CAPN10) is a cysteine protease that is activated by intracellular calcium (Ca2+) and known to be involved in diseases such as cancer, heart attack, and stroke. A role for the CAPNI0 gene in diabetes mellitus type II was recently identified. Hyper activation of the enzyme initiates a series of destructive cycles that can cause irreversible damage to cells. The development of inhibitors may be useful as therapeutic agents for a number of calpainopathies. In this paper, we have used the homology modelling technique to determine the 3D structure of calpain-10 from Homo sapiens. The model of calpain-10 obtained by homology modelling suggests that its active site is conserved among family members and the main interactions are similar to those observed for μ-calpain. Structural analysis revealed that there are small differences in the charge distribution and molecular surface of the enzyme. These differences are probably less dependent on calcium for calpain-10 than they are for -calpain. In addition, the ion pair Cys-/His+ formation was observed using of Molecular Dynamics (MD) simulations that were based upon hybrid quantum mechanical/molecular mechanical (QM/MM) approaches. Finally, the binding of the SNJ-1715 inhibitor to calpain-10 was investigated in order to further understand the mechanism of inhibition of calpain-10 by this inhibitor at the molecular level. [ABSTRACT FROM AUTHOR]

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Objective: To examine the role of calpain-10 SNP-44, -43, -63 and del/ins-19 in genetic susceptibility to type 2 diabetes mellitus (T2DM) and associations with triglycerides and total cholesterol in a group of subjects residing in the Gaza Strip. Subjects and Methods: Ninety-six individuals were examined: 48 T2DM patients and 48 controls. The groups were genotyped for calpain-10 SNP-44, -43, -63, and del/ins-19. Mutagenically separated polymerase chain reaction was used to examine SNP-44; del/ins-19 was examined by electrophoresis of the PCR product on agarose gel, while the restriction fragment length polymorphism method was used for SNP-43 and -63. Results: There was evidence that the C allele at SNP-44 played a possible role in susceptibility to T2DM (p = 0.01). T2DM patients with G/A genotype were found to have higher levels of total cholesterol in comparison to those homozygous for allele 1 (G/G) in SNP-43. Total cholesterol levels increased in T2DM patients who are homozygous for del/ins-19 allele 2, in T2DM patients with the 121/221 haplotype combination, and in control subjects with the haplotype combination 111/121. Conclusion: SNP-44 polymorphism of the calpain-10 gene has a significant association with T2DM patients in the Gaza strip. Certain polymorphisms of calpain-10 also have associations with the levels of total cholesterol in both T2DM patients and controls. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to test the association between calpain-10 ( CAPN10), a diabetes susceptibility gene, with risk of pancreatic cancer (PC). Methods: DNA samples from 83 incident exocrine PC cases and 166 controls, all of whom were smokers, were genotyped for four markers of CAPN10 in a nested case-control study based on the Beta-Carotene and Retinol Efficacy Trial (CARET), a randomized chemoprevention trial of subjects at high risk of lung cancer. Controls were matched on sex, race, age, CARET intervention arm, duration of exposure to asbestos, and smoking history. Conditional logistic regression was used for statistical analyses. Results: The minor allele of SNP-43 (rs3792267) in intron 3 was associated with increased risk of PC with an odds ratio of 1.57 (95%CI 1.03-2.38, p = 0.035) per allele. The three markers of the highest risk haplotype had an odds ratio of 1.98 (95%CI 1.12-3.49, p = 0.019) for risk of PC compared to the most common haplotype. There was no evidence of interaction between either of these associations by diabetes status. Conclusion: These results suggest that variation in CAPN10 may be associated with increased risk of PC among smokers. Thus, studies of genes associated with diabetes risk in PC are warranted in a larger population. [ABSTRACT FROM AUTHOR]

Calpain-10 (CAPN10) belongs to the calpain superfamily. Genetic polymorphisms of the CAPN10 gene are associated with susceptibility to develop type 2 diabetes mellitus. Although the role of CAPN10 in the pathophysiology of diabetes has been extensively investigated, its biochemical properties are largely unknown. In this report, we made the surprising discovery that CAPN10 cDNA transcripts are subject to cryptic splicing and unexpected protein products were expressed. The same set of splicing products was reproducibly detected in four types of cultured cells including the primary culture of mouse myoblast. At least, one of the products was identical to a natural splicing variant. Sequence analysis of the splicing potential of CAPN10 cDNA, together with mutagenesis studies, resulted in the identification of a powerful splicing acceptor site at the junction of the sequences encoded by exons 9 and 10. We successfully extended the analysis to create expression construct resistant to splicing for both human and mouse CAPN10. The construct allowed us to analyze two major CAPN10 isoforms and reveal their difference in substrate proteolysis and potential cell functions. These results demonstrate that proteins produced from cDNA do not necessarily reflect the original nucleotide sequence. We provide insight into the property of recombinantly expressed CAPN10 proteins in cultured cells circumventing unexpected protein products. [Display omitted] • Discrepancy between the cDNA sequence of CAPN10 and its protein product is noticed. • The CAPN10 cDNA transcripts are subject to cryptic splicing when expressed in cells. • Splicing-resistant cDNA construct for CAPN10 enables structure-function analysis. • Two splicing isoforms, CAPN10a and CAPN10c, have different cellular targets. • Impact of alternative splicing in regulating CAPN10 functions deserves more studies. [ABSTRACT FROM AUTHOR]

Abstract: Background: Studies have suggested that the Calpain-10 gene polymorphisms may play a role in polycystic ovary syndrome (PCOS) susceptibility. Thus, the aim of the present study was to evaluate the possible association between three single nucleotide polymorphisms (SNPs) in the calpain-10 gene (UCSNPs -43, -19, and -63) and polycystic ovary syndrome (PCOS) in Chilean women. Methods: Fifty women with PCOS (28.8±8.2 y) and 70 healthy women (28.6±8.6 y) were included in this study. Serum lipids, hormonal status, fasting glucose, oral glucose tolerance test (OGTT), insulin, HOMAIR, and uric acid levels were determined by conventional methods. The calpain-10 gene variants were detected by PCR and PCR-RFLP, respectively. Results: The presence of uncommon allele (A) for the UCSNP-43 was associated with increased risk of PCOS (odds ratio=1.93, 95% CI: 1.11–3.34). The UCSNP-63 (OR=1.11, 95% CI: 0.59–2.11) and UCSNP-19 (OR=0.93, 95% CI: 0.55–1.57) were not associated to PCOS. However, the PCOS women carrying the CC genotype for UCSNP-63 exhibited higher values of total cholesterol and LDL-C (P <0.05). Similarly, control women carrying the CC genotype showed higher serum levels of triglycerides, HDL-C and uric acid (P <0.05). Conclusion: Our data suggest the contribution of CAPN10 UCSNP-43 gene polymorphism to PCOS in Chilean women. However, further studies with larger samples are necessary to confirm this observation. [Copyright &y& Elsevier]

Abstract: Calpain-10 is a novel ubiquitous calpain family member that has been implicated as a susceptibility gene for type 2 diabetes. One of the major challenges is that the function of calpain-10 is not yet known. To address this problem, we purified human calpain-10 from different sources, including the endogenous and the recombinant calpain-10 from HeLa S3 and 293F cells, respectively. Both endogenous and recombinant calpain-10 were present as two major forms with different origins. Interestingly, radiolabeled calpain-10 was found to be efficiently cleaved at the N-terminal region by calpain-2, but not by other proteases. None of these calpain-10 proteins have putative proteolytic activity under in vitro conditions when examined using different peptide substrates, including more than 70 in vitro translated, radiolabeled oligopeptides. Our results raise the possibility that calpain-10 may require a special intracellular localization or interacting partner(s) to acquire proteolytic activity, or it functions by interacting with other proteins rather than through its proteolytic activity. [Copyright &y& Elsevier]

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. [Copyright &y& Elsevier]

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder with individual susceptibility determined by genetic and environmental risk factors. Recently, studies have evaluated the CAPN10 gene in PCOS patients, suggesting that different alleles may play a role in PCOS susceptibility. We performed a cross-sectional study with 88 southern Brazilian hirsute patients with PCOS or idiopathic hirsutism (IH) to assess the influence of CAPN10 genetic variants on clinical and biochemical features of metabolic syndrome. PCOS patients were defined by oligo/amenorrheic cycles (<9 cycles/year), increased levels of serum testosterone and/or free androgen index, and exclusion of other disorders associated with hyperandrogenism. IH was diagnosed in hirsute patients with regular ovulatory cycles (luteal-phase progesterone levels >3.8 ng/ml), normal androgen levels, and without any known underlying disease (n = 29). Metabolic syndrome was defined according to the 2001 criteria of the National Cholesterol Education Program, Adult Treatment Panel III. UCSNP-43 polymorphism of CAPN10 was related to metabolic syndrome (p = 0.047) in PCOS; UCSNP-19 and UCSNP-63 were not associated with phenotypic traits in PCOS. These results provide evidence that CAPN10 gene UCSNP-43 polymorphisms may influence the PCOS metabolic phenotype. This should be further confirmed in large population-based studies. [ABSTRACT FROM AUTHOR]

Abstract: We conducted pooled and meta-analyses of the association of the calpain-10 gene (CAPN10) polymorphisms SNP-43, Indel-19 and SNP-63 individually and as haplotypes with type 2 diabetes (T2D) in 3237 patients and 2935 controls of European ancestry. In the pooled analyses, the common SNP-43*G allele was associated with modest but statistically significant increased risk of T2D (odds ratio (OR)=1.11 (95% confidence interval (CI), 1.02–1.20), P =0.01). Two haplotype combinations were associated with increased risk of T2D (1-2-1/1-2-1, OR=1.20 (1.03–1.41), P =0.02; and 1-1-2/1-2-1, OR=1.26 (1.01–1.59), P =0.04) and one with decreased risk (1-1-1/2-2-1, OR=0.86 (0.75–0.99), P =0.03). The meta-analysis also showed a significant effect of the 1-2-1/1-2-1 haplogenotype on risk (OR=1.25 (1.05–1.50), P =0.01). However, there was evidence for heterogeneity with respect to this effect (P =0.06). The heterogeneity appeared to be due to data sets in which the cases were selected from samples used in linkage studies of T2D. Using only the population-based case-control samples removed the heterogeneity (P =0.89) and strengthened the evidence for association with T2D in both the pooled (SNP-43*G, OR=1.19 (1.07–1.32), P =0.001; 1-2-1/1-2-1 haplogenotype, OR=1.46 (1.19–1.78), P =0.0003; 1-1-2/1-2-1 haplogenotype, OR=1.52 (1.12–2.06), P =0.007; and 1-1-1/2-2-1 haplogenotype, OR=0.83 (0.70–0.99), P =0.03) and the meta-analysis (SNP-43*G, OR=1.18 (1.05–1.32), P =0.005; 1-2-1/1-2-1 haplogenotype, OR=1.68 (1.33–2.11), P =0.00001). The pooled and meta-analyses as well as the linkage disequilibrium and haplotype diversity studies suggest a role for genetic variation in CAPN10 affecting risk of T2D in Europeans. [Copyright &y& Elsevier]

Abstract: Patients with metabolic syndrome are at increased risk of developing cardiovascular disease. The combinations of the haplotype created by the alleles of three single nucleotide polymorphisms (SNPs): SNP-43, -19, and -63 of the Calpain-10 gene (CAPN10), have been reported to be associated with the risk of type 2 diabetes in many populations. The aim of this study was to examine the association of the CAPN10 polymorphism with metabolic syndrome in patients with type 2 diabetes in Korea. Overall, 382 patients with type 2 diabetes were enrolled in this study. All the subjects were genotyped according to CAPN10 SNP-43, -19, and -63. The restriction fragment length polymorphism method was used for the three SNPs. The baseline presence of components of metabolic syndrome was determined. Two hundred and sixty-five (69.4%) patients had metabolic syndrome. Patients with the 111/121 haplotype combination showed a higher risk of hypertension than the other haplotype combinations (odd ratio (OR)=2.334, P =0.010). Patients with the 111/121 haplotype combination had a significantly high risk of metabolic syndrome (OR=1.927, P =0.042). The results of this study suggest that a novel 111/121 haplotype combination created by the CAPN10 SNP-43, -19, and -63 increases the susceptibility to the metabolic syndrome in patients with type 2 diabetes. [Copyright &y& Elsevier]

Genetic variations in the Calpain-10 gene, CAPN10, have been reported to be associated with the risk of type 2 diabetes mellitus (T2DM) in Mexican-Americans and Northern Europeans whereas these variations are not associated with T2DM in other populations. The aim of this study was to determine whether there is an association between specific CAPN10 diplotype (SNP-43, -19, and -63) and T2DM in the Korean population. Overall, 454 Korean patients with T2DM (male 230, female 224) and 236 non-diabetic controls (male 124, female 112) with no family history of diabetes were enrolled in this study. All the subjects were genotyped according to CAPN10 SNP-43, -19, and -63. The restriction fragment length polymorphism method was used for the three SNPs. There were eight estimated haplotype allelic variations. After adjusting for gender and age, the 111 haplotype was associated with a high risk of T2DM ( P <0.0001). The 111/121 diplotype was associated with a high risk of T2DM (odds ratio =2.580, 95% confidence interval =1.602–4.155, P =0.001). The high-risk haplotype (112/121) in Mexican-Americans was not significant in our study population. In conclusion, we found that a novel 111/121 diplotype in Calpain-10 gene is associated with T2DM in the Korean population. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: The mechanisms by which the calpain-10 gene (CAPN10) affects the risk of type 2 diabetes are unclear. Therefore, we investigated the effects of four polymorphisms in CAPN10 (single nucleotide polymorphism [SNP]-43, SNP-44, Insertion/Deletion [Indel]-19 and SNP-63) on insulin secretion, insulin action and abdominal fat distribution in offspring of patients with type 2 diabetes. Subjects and methods: Insulin secretion was determined by an IVGTT, insulin action by the hyperinsulinaemic-euglycaemic clamp and abdominal fat distribution by computed tomography in 158 non-diabetic offspring (age 34.9±6.3 years [mean±SD], BMI 26.2± 4.9 kg/m²) of type 2 diabetic patients. Results: SNP-43 (p=0.009 over the three genotypes, adjusted for age, sex, BMI and family relationship) and haplotypes carrying the A allele of SNP-43 were associated with intra-abdominal fat area. The A allele of SNP-43 was associated with intraabdominal fat area in men (p=0.014) but not in women. SNP-44, InDel-19, and SNP-63 were not associated with intra-abdominal fat area or insulin action. Furthermore, we demonstrated in a separate sample of middle-aged men (n=234) who had a history of type 2 diabetes in first-degree relatives that the A allele of SNP-43 was associated with a large waist circumference, and high insulin levels in an OGTT. Conclusions/interpretation: SNP-43 of CAPN10 may contribute to the risk of diabetes by regulating abdominal obesity in subjects with high risk of type 2 diabetes. [ABSTRACT FROM AUTHOR]

Linkage- and association-based approaches have been applied to attempt to unravel the genetic predisposition for complex diseases. However, studies often report contradictory results even when similar population backgrounds are investigated. Unrecognized population substructures could possibly explain these inconsistencies. In an apparently homogeneous German sample of 612 patients with type 2 diabetic and end-stage diabetic nephropathy and 214 healthy controls, we tested for hidden population substructures and their possible effects on association. Using a genetic vector space analysis of genotypes of 20 microsatellite markers, we identified four distinct subsets of cases and controls. The significance of these substructures was demonstrated by subsequent association analyses, using three genetic markers (UCSNP-43,-19,-63; intron 3 of the calpain-10 gene). In the undivided sample, we found no association between individual SNPs or any haplogenotypes (ie the genotype combination of two multilocus haplotypes) and type 2 diabetes. In contrast, when analyzing the four groups separately, we found that there was evidence for association of the common C allele of UCSNP-63 with the trait in the largest group (n=547 cases/101 controls; P=0.002). In this subset haplotype 112 was more frequent in controls than in cases (P=0.006; haplogenotype 112/121: odds ratio (OR)=0.27, 95% confidence intervals (CI)=0.13–0.57), indicating a protective effect against the development of type 2 diabetes. Our study demonstrates that unconsidered population substructures (ethnicity-dependent factors) can severely bias association studies.European Journal of Human Genetics (2006) 14, 236–244. doi:10.1038/sj.ejhg.5201546; published online 7 December 2005 [ABSTRACT FROM AUTHOR]

Abstract: Variants of calpain-10 gene (CAPN 10) have recently been reported to be associated with type 2 diabetes (T2DM). Haplotype combination 112/121 defined by three single nucleotide polymorphisms (SNPs) (UCSNP-43, -19 and -63) of CAPN 10 conferred the highest risk for T2DM in Mexican-Americans. In this study, we aim to examine whether these genetic variants contribute to the susceptibility for T2DM in a Chinese population. The frequencies of these three SNPs were determined in 168 patients with T2DM and 104 controls. Distribution of alleles, genotypes and haplotypes at three loci were not significantly different between the two groups. No difference was observed in the 112/121 haplotype combination distribution. However, haplotype combination 112/221 was more prevalent in the control group than in T2DM group (16.35% versus 7.14%, p =0.025). Control subjects with haplotype combination 112/121 had higher serum cholesterol level than others without haplotype combination 112/121 (5.7±1.4 versus 5.2±0.7, p =0.011). Our results suggest that haplotype combination 112/221 associated with reduced risk for T2DM and haplotype combination 112/121 might be a risk factor for increased serum cholesterol in Chinese population. [Copyright &y& Elsevier]

Variation in the gene encoding the cysteine protease calpain-10 has been linked and associated with risk of type 2 diabetes. We have examined the effect of three polymorphisms in the calpain-10 gene (SNP-43, Indel-19, and SNP-63) on the development of type 2 diabetes in the Japanese population in a pooled analysis of 927 patients and 929 controls. We observed that SNP-43, Indel-19, and SNP-63 either individually or as a haplotype were not associated with altered risk of type 2 diabetes with the exception of the rare 111/221 haplogenotype (odds ratio (OR) =3.53,P=0.02). However, stratification based on the median age-at-diagnosis in the pooled study population (<50 and =50 years) revealed that allele 2 of Indel-19 and the 121 haplotype were associated with reduced risk in patients with later age-at-diagnosis (age-at-diagnosis =50 years OR=0.82 and 0.80, respectively;P=0.04 and 0.02). Thus, variation in the calpain-10 gene may affect risk of type 2 diabetes in Japanese, especially in older individuals. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether the three single nucleotide polymorphisms (SNPs), SNP-43, -56, and -63 of CAPN10 were associated with type 2 diabetes in a West African cohort. Methods: A total of 347 diabetic subjects and 148 unaffected controls from four ethnic groups in two West African countries were enrolled in this study. After genotyping three SNPs of CAPN10 and one SNP from CYP19, the allele, genotype, and haplotype frequencies as well as the odds ratios were calculated to test their association with type 2 diabetes. Results: None of the alleles or genotypes was associated with type 2 diabetes. Although statistical analysis indicated that haplotype 221 was associated with type 2 diabetes (OR, 3.765; 95% CI, 1.577–8.989) in the two ethnic groups of Nigeria, the same haplotype did not show any association with type 2 diabetes in the two ethnic groups in Ghana (OR, 0.906; 95% CI, 0.322–2.552). Conclusion: Considering the relatively low frequency of haplotype 221 and that none of the haplotypes including 221 was associated with any of the diabetes-related quantitative traits tested, it is concluded that SNP-43, -56, and -63 of the CAPN10 gene variants may play a limited role in the risk of type 2 diabetes risks in this cohort of West Africans. [Copyright &y& Elsevier]

In order to determine whether the variations in the calpain-10 gene constitutes risk of type 2 diabetes (T2DM) in Chinese, the frequency of UCSNP-43, 44 in 268 adults newly diagnosed with T2DM (according to the 1999 ADA criteria) and 153 non-diabetic control subjects was investigated. For all subjects, the height, weight, waist-to-hip ratio (W/H) and blood pressure, as well as following parameters were measured: (1) 75-g oral glucose tolerance test with insulin, C-peptide, HbAlc and blood lipid profiles; (2) Genomic DNA extracted from peripheral blood lymphocytes was genotyped for UCSNP-43 (calpain-10-g. 4852 G/A) and UCSNP-44 (calpain-10-g. 4841 T/C by sequencing a polymerase chain reaction (PCR)-amplified fragment. PCR product was selected by single strand conformation polymorphism (SSCP) and then sequenced. The results showed that there was significant difference between T2DM group and normal control group in allele frequencies, haplotype frequencies, or haplotype combinations of UCSNP-43 and-44 either. But in newly diagnosed T2DM group, it was found that the individuals with the genotype UCSNP-44 T/C+C/C had significantly increased fasting and post-challenge insulin levels (FIns and P2hIns), consistent with reduced insulin sensitivity. In the BMI>25 subgroup, the differences were even more significant. It was demonstrated that the Calpain-10 gene polymorphism UCSNP-44 was associated with insulin sensitivity and FIns and P2hIns in newly diagnosed T2DM, although Calpain-10 doesn't appear as a major diabetes susceptible gene in this population. [ABSTRACT FROM AUTHOR]

Background: An association of variations in the calpain-10 gene (CAPN10) with type 2 diabetes was originally reported in Mexican Americans. However, some studies in other racial groups were contradictory. Methods: We studied the influence of genotypes and haplotype combinations (haplogenotypes) of CAPN10 on the metabolic traits in 286 Japanese subjects who visited a General Health Check-up Center. Results: As for single nucleotide polymorphism (SNP)-19, subjects with genotype 22 had higher body mass index (BMI) and hemoglobin A1c (HbA1c) levels than those with genotypes 11 and 12 (p=0.003 and p=0.024, respectively). In SNP-63, subjects with genotype 11 had higher BMI and HbA1c levels than those with genotypes 12 and 22 (p=0.003 and p=0.045, respectively). Subjects who had genotype 22 at SNP-19 always had genotype 11 at SNP-63. Subjects with haplogenotype 121/121 had higher BMI levels (p=0.021) and tended to have higher HbA1c levels (p=0.08) than those with other haplogenotypes. All things considered, SNP-19 genotype 22, which was composed of haplogenotype 121/121 and 121/221, had highest significance level of association with elevated HbA1c levels. SNP-43 did not affect metabolic traits in our subjects. Subjects with haplogenotype 112/121 rather showed lower BMI and HbA1c levels (p=0.016 and p=0.008) than those with all other haplogenotypes. Conclusions: These results indicate the contribution of SNP-19 in CAPN10 to mild obesity and glucose intolerance in Japanese. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Diabetes and atherosclerosis may share common genetic determinants. A prior study in Hispanics found association of haplotypes in the diabetes gene calpain-10 (CAPN10) with carotid artery intima-media thickness (CIMT). This study sought to replicate this association in an independent cohort. Methods: Four CAPN10 SNPs were genotyped and haplotypes determined in 487 Hispanic Americans from 143 families ascertained via an index case with hypertension. CIMT was measured from B-mode ultrasound, and glycemic traits quantified from euglycemic clamps. Association of SNPs and haplotypes with CIMT was determined. Results: The minor alleles of SNP-56 and SNP-63 were associated with increased CIMT in dominant and additive models. The association of haplotype 1112 with increased CIMT was replicated. No associations with fasting insulin, insulin secretion, or insulin sensitivity were observed. Conclusions: CAPN10 association with CIMT was replicated, further supporting its role as a common genetic determinant of diabetes and atherosclerosis in Hispanics. [Copyright &y& Elsevier]

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 β-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. [Copyright &y& Elsevier]

Human epidermal growth factor receptor 2 (HER2) is composed of an extracellular domain (ECD), a lipophilic transmembrane region and an intracellular domain (ICD). The most commonly used method to determine the status of HER2 is immunohistochemistry. However, false‑negative results are sometimes given, which causes some patients to lose the opportunity for anti‑HER2 therapy. We found that calpain‑10 may prohibit HER2‑ECD into peripheral blood resulting in a HER2‑negative result by the immunohistochemical method. We enrolled 289 patients into our experiment to assess the relationship between sHER2‑ECD and calpain‑10. The results showed that there was a positive correlation between sHER2‑ECD and calpain‑10. Moreover, we also investigated the prognostic values of sHER2‑ECD and calpain‑10 in breast cancer patients. According to the follow‑up results, positive sHER2‑ECD and tissue calpain‑10 were indicative of a poor prognosis in breast cancer patients. Subsequently, we further validated the relationship between the two molecules in in vitro experiments. In the in vitro experiments, the level of HER2‑ECD in the culture medium was increased or decreased with a decrease or increase in calpain‑10 by transfection technology, showing an inverse association. The results indicated that sHER2‑ECD and tissue calpain‑10 levels were powerful factors to assess the status of HER2. In combination with tissue HER2 detection, the occurrence of false‑negative HER2 was reduced, providing patients with additional treatment opportunities. In conclusion, sHER2‑ECD and tissue calpain‑10 may be used as new prognostic indices for breast cancer.

• An updated meta-analysis on CAPN10 polymorphism associations with PCOS is require.d • Deviation from Hardy-Weinberg Equilibrium in control groups should be highlighted. • Essential statistical methods are often overlooked when conducting a meta-analysis. • Genotype models should be properly investigated in meta-analysis studies. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM) accounts for the majority of diabetes cases and affects a significant proportion of the adult population worldwide. Calpain-10 has been implicated in the development of type 2 diabetes, and some polymorphisms in the CAPN10 gene have been associated with an increased risk of developing this disease. Several molecular epidemiological studies were conducted in recent years to evaluate the association between the CAPN10 rs2975760 polymorphism and T2DM risk in diverse populations. However, the results remain conflicting rather than conclusive. We performed a meta-analysis of 8 case-control studies that included 2758 T2DM cases and 2762 case-free controls. We assessed the strength of the association, using odds ratios (ORs) with 95% confi dence intervals (CIs). Overall, this meta-analysis showed that the CAPN10 rs2975760 polymorphism was not associated with a significantly type 2 diabetes risk in three genetic models. However, after excluding two study for its heterogeneity, a significantly increased risk was found in all comparisons (for C vs T: OR=1.14, 95% CI=1.03-1.27, I (2)=0, P heterpgeneity=0.420, P b=0.012; for TC vs TT: OR=1.15, 95% CI=1.01-1.30, I (2)=3.8%, P heterpgeneity=0.392, P b=0.030; for CC+TC vs TT: OR=1.16, 95% CI=1.03-1.31, I (2)=3.7%, P heterpgeneity=0.393, P b=0.015). No publication bias was found in the present study. This meta-analysis suggests that the C allele of the CAPN10 rs2975760 polymorphism is associated with an increased T2DM risk. Further large and well-designed studies are needed to confi rm this association.