Association of the PIK3C2G gene polymorphisms with type 2 DM in a Japanese population

The associations of five SNPs (SNPs1-5: A-5468G, A-3333G, C-1794T, C437T and T9148C) of the class II phosphoinositide 3-kinase γ-subunit (PIK3C2G) gene with type 2 diabetes were examined using a population of the Takahata Study (n (M/W): 2930 (1328/1602); age: 63.3 ± 10.2 years), a Japanese community-based study. Quantitative association study of the SNPs with HbA1c levels showed significant association for SNPs 2 and 4 (p = 0.018 and 0.004, respectively). A case-control association study of SNP 4 with diabetes by multiple logistic regression analysis showed a significant association of the genotype TT of the SNP with an odds ratio of 2.21 (p = 0.001) independently of age, gender and BMI. In the NGT subjects, serum fasting insulin levels in the at-risk genotype group of SNP 4 were significantly lower than those in the others (TT, TC, and CC, 4.9 ± 2.6, 5.4 ± 3.0, and 5.6 ± 3.4 μU/ml, respectively; p = 0.029).     

Association of GNB3 C825T polymorphism with plasma electrolyte balance and susceptibility to hypertension

The role of G-protein activation in cardiovascular disorders is well-known. G-protein β3 subunit (GNB3) C825T polymorphism is associated with increased intracellular signal transduction. We investigated the role of the variant in plasma sodium and potassium concentrations and association with hypertension. 345 healthy controls and 455 patients with essential hypertension were enrolled. Plasma renin activity and aldosterone concentration were measured. The variant, typed by SNaPshot, was analyzed on an ABI Prism 3100 Genetic Analyzer and GeneScan. The TT genotype and T allele were over-represented in the patients (p < 0.001, p < 0.0001). Multiple-logistic regression disclosed that the risk of hypertension was significantly greater for TT (p < 0.0001, OR = 6.1, CI = 2.9-12.7). One-way ANOVA revealed that hypertensive T-allele carriers (CT+TT), compared to non-carriers (CC), had a greater body mass index (BMI), mean arterial pressure (MAP) and PAC (p = 0.01, p = 0.01, p < 0.0001, respectively); while the patients with 825TT risk genotype showed higher plasma sodium and lower potassium (p < 0.0001, each). The results strongly emphasize, not only the role of C825T polymorphism by the induction of increased G-protein activity and enhancement of Na/h exchangers, but also the association with higher plasma sodium and lower potassium levels, high BMI and susceptibility to hypertension.     

Allelic variants interaction of CLOCK gene and G-protein beta3 subunit gene with diurnal preference

The 3111 C/T single nucleotide polymorphism (SNP) in the CLOCK gene and the 825C/T SNP in the G-protein β3 subunit gene (GNB3) have been reported to influence diurnal preference. This study has attempted to characterize the association between the CLOCK gene and GNB3 polymorphisms and diurnal preference in healthy Korean college students. All subjects completed the 13-item Composite Scale for Morningness (CSM). The interaction between the 3111 C/T SNP in the CLOCK gene and the 825 C/T SNP in the GNB3 gene significantly influenced diurnal preference, according to the CSM Performance subscore (F=10.94, p=0.001). However, when the different polymorphisms of the two genes were analyzed independently, no direct correlations with diurnal preference were detected. The CLOCK gene 3111 C/T SNP and GNB3 gene 825 C/T SNP were found to manifest a gene-gene interaction that affects diurnal preference.     

Association of the C825T polymorphism in the GNB3 gene with obesity and metabolic phenotypes in a Taiwanese population

The relationship between obesity and a single nucleotide polymorphism (SNP), rs5443 (C825T), in the guanine nucleotide binding protein beta polypeptide 3 (GNB3) gene is currently inconsistent. In this study, we aimed to reassess whether the GNB3 rs5443 SNP could influence obesity and obesity-related metabolic traits in a Taiwanese population. A total of 983 Taiwanese subjects with general health examinations were genotyped. Based on the criteria defined by the Department of Health in Taiwan, the terms “overweight” and “obesity” are defined as 24 ≦ BMI < 27 and BMI ≧ 27, respectively. Compared to the carrier of the combined CT + TT genotypes of the GNB3 rs5443 polymorphism, triglyceride was significantly higher for the carrier of CC genotype in the complete sample population (128.2 ± 93.2 vs. 114.3 ± 79.1 mg/dl; P = 0.041). In addition, the carriers of CC variant had a higher total cholesterol than those with the combined CT + TT variants (194.5 ± 36.8 vs. 187.9 ± 33.0 mg/dl; P = 0.019) in the complete sample population. In the normal controls, both triglyceride (P = 0.018) and total cholesterol (P = 0.011) were also significantly higher in the CC homozygotes than in the combined CT + TT genotypes. However, the GNB3 rs5443 SNP did not exhibit any significant association with obesity or overweight among the subjects. Our study indicates that the CC genotype of the GNB3 rs5443 SNP may predict higher obesity-related metabolic traits such as triglyceride and total cholesterol in non-obese Taiwanese subjects (but not in obese subjects).     

Association of the Ser326Cys polymorphism in the OGG1 gene with type 2 DM

The association of the Ser326Cys polymorphism of the 8-oxoguanine glycosylase 1 (OGG1) gene with type 2 diabetes was examined using a Japanese population (n (M/W): 4585 (2085/2500); age: 62.6 ± 10.9 years). HbA1c levels and frequency of diabetic subjects were significantly higher in subjects with genotypes with Cys allele than in those without (p = 0.032 and 0.037, respectively). Multiple logistic regression analysis showed that genotypes with Cys allele were significantly associated with diabetes (OR: 1.32, p = 0.0289). In subjects whose glucose tolerance was classified by FPG and 2-h PG (n = 1.634), the association was more substantial (genotypes with Cys allele vs. without, OR: 1.70, p = 0.0059; genotypes Cys/Cys vs. Ser/Ser, OR: 2.19, p = 0.0008). In subjects with genotype Ser/Ser, the insulin secretion index, HOMA-β, increased in the subjects with glucose intolerance and decreased in the subjects with diabetes, while, in subjects with genotypes Ser/Cys + Cys/Cys, HOMA-β decreased as the glucose tolerance progressed (p for trend = 0.010).     

在中国北方汉族人群中血管紧张素转换酶基因I/D多态与G蛋白beta3亚基基因C825T多态对原发性高血压的联合作用

原发性高血压是一种复杂的多基因疾病,被认为是多个变异了的基因遗传交互以及环境因素共同作用的结果.证据表明,血管紧张素转换酶基因和G蛋白beta3亚基基因各自都是重要的原发性高血压的易感基因,并且可能存在共同的通路来导致高血压疾病的发展.为了探索这两个基因在中国北方汉族人群中是否对高血压有影响,挑选血管紧张素转换酶基因I/D多态与G蛋白beta3亚基基因C825T多态,在一个包含502个高血压病例和490个健康对照的样本中做了关联研究.连锁不平衡分析揭示,仅仅在男性中有显著性的非随机性分布,表明血管紧张素转换酶基因与G蛋白beta3亚基基因倾向在男性中造成高血压.调整了的单位点的多变量逐步回归分析展示,在男性显性模型中DD/ID对Ⅱ的比值比达到显著性水平(OR1.57;95%CI,1.09～2.27;P=0.016).在对性别进行分层后的联合分析中,在男性中经过调整后的比值比具有弱显著性水平:在血管紧张素转换酶基因的DD基因型中,TT对CC的比值比是0.11;95%CI,0.01～0.99;P=0.049;在G蛋白beta3亚基基因的CC CT基因型中,DD/ID对Ⅱ的比值比是1.52;95%CI,1.01～2.29;P=0.047.结果暗示,血管紧张素转换酶基因或附近的某个基因是具有男性性别倾向的高血压易感侯选基因,同时,在血管紧张素转换酶基因基因的D等位基因和G蛋白beta3亚基基因的825C等位基因之间,可能存在具有上位效应的基因-基因相互作用.     

In vitro effect of gliclazide on DNA damage and repair in patients with type 2 diabetes mellitus (T2DM)

Type 2 diabetes mellitus is associated with elevated level of oxidative stress, which is one of the most important factors responsible for the development of chronic complications of this disease. Moreover, it was shown that diabetic patients had increased level of oxidative DNA damage and decreased effectiveness of DNA repair. These changes may be associated with increased risk of cancer in T2DM patients, since DNA damage and DNA repair play a pivotal role in malignant transformation. It was found that gliclazide, an oral hypoglycemic drug with antioxidant properties, diminished DNA damage induced by free radicals. Therefore, the aim of the present study was to evaluate the in vitro impact of gliclazide on: (i) endogenous basal and oxidative DNA damage, (ii) DNA damage induced by hydrogen peroxide and (iii) the efficacy of DNA repair of such damage. DNA damage and DNA repair in peripheral blood lymphocytes of 30 T2DM patients and 30 non-diabetic individuals were evaluated by alkaline single cell electrophoresis (comet) assay. The extent of oxidative DNA damage was assessed by DNA repair enzymes: endonuclease III and formamidopyrimidine-DNA glycosylase. The endogenous basal and oxidative DNA damages were higher in lymphocytes of T2DM patients compared to non-diabetic subjects and gliclazide decreased the level of such damage. The drug significantly decreased the level of DNA damage induced by hydrogen peroxide in both groups. Gliclazide increased the effectiveness of DNA repair in lymphocytes of T2DM patients (93.4% (with gliclazide) vs 79.9% (without gliclazide); P< or =0.001) and non-diabetic subjects (95.1% (with gliclazide) vs 90.5% (without gliclazide); P< or =0.001). These results suggest that gliclazide may protect against the oxidative stress-related chronic diabetes complications, including cancer, by decreasing the level of DNA damage induced by reactive oxygen species.     

Genetic association of adiponectin with type 2 diabetes in Jordanian Arab population

Adiponectin, a protein exclusively secreted by adipose tissue and present at low levels in obese individuals, is now widely recognized as a key determinant of insulin sensitivity and protection against obesity-associated metabolic syndrome. In Jordan, prevalence of diabetes (17.1%) is twice that of the United States (7.8%). In this study, we examined the contribution of the promoter variant rs266729 (− 11377C>G) of the ADIPOQ gene as a risk factor for diabetic patients in Jordan. DNA was extracted from blood samples for patients and controls .Polymerase chain reaction and restriction fragment length polymorphism were used to genotype this variant. A total of 420 type 2 diabetic patients and 230 controls were successfully genotyped. The results showed a significant genotypic (p = 0.00001) and allelic (p = 0.01) association with variant in the diabetic patients as compared to controls. This suggests that the ADIPOQ gene plays a major role in increasing the risk of diabetes, at least in the Jordanian Arab population.     

Association of GNB3 gene C825T polymorphism with coronary heart disease

The C825T polymorphism in the gene encoding the G protein beta 3 subunit (GNB3) causes enhanced G protein activation and the increased in vitro cell proliferation. We investigated the association of gene GNB3 C825T polymorphism with coronary artery disease (CAD) in the Russian population. A total of 313 patients with CAD diagnosed on the basis of clinical studies and coronary angyography were examined. The control group included 132 individuals that lacked clinical CAD symptoms and had matching profile of coronary artery disease risk factors. Blood pressure was measured using standard protocols. Increased levels of diastolic and systolic pressure was observed in both groups. The allele and genotype frequencies of this polimorphic marker were significantly higher in the CAD patients than in control. We found that the frequency of allele C and genotype CC was significantly higher in the CAD patients (OR = 1.55; P = 0.0079; OR = 1.63; P = 0.0215, respectively), which suggests higher risk of this pathology in carriers of allele C and genotype CC. Thus, in the Russian population coronary artery disease is associated with GNB3 allele C and genotype CC.     

Association of GNB3 gene C825T polymorphism with coronary heart disease

The C825T polymorphism in the gene encoding the G protein beta 3 subunit (GNB3) causes enhanced G protein activation and the increased in vitro cell proliferation. We investigated the association of gene GNB3 C825T polymorphism with coronary artery disease (CAD) in the Russian population. A total of 313 patients with CAD diagnosed on the basis of clinical studies and coronary angyography were examined. The control group included 132 individuals that lacked clinical CAD symptoms and had matching profile of coronary artery disease risk factors. Blood pressure was measured using standard protocols. Increased levels of diastolic and systolic pressure was observed in both groups. The allele and genotype frequencies of this polimorphic marker were significantly higher in the CAD patients than in control. We found that the frequency of allele C and gen-. otype CC was significantly higher in the CAD patients (OR = 1.55; P = 0.0079; OR = 1.63; P = 0.0215, respectively), which suggests higher risk of this pathology in carriers of allele C and genotype CC. Thus, in the Russian population coronary artery disease is associated with GNB3 allele C and genotype CC.     

自发性与膳食诱发性食蟹猴2型糖尿病其相关基因的表达比较

采用荧光定量PCR技术对自发性和膳食诱发性T2DM食蟹猴外周血白细胞中36个糖尿病相关基因的表达水平进行分析。在36个基因中,糖尿病组的G6PC、CCR2B、CTLA4等19个基因的表达量与对照组相比存在显著差异(P<0.05),且这些基因在诱发组和自发组中的表达模式基本一致。36个基因中,诱发组基因的表达量普遍高于自发组,但大部分基因表达量在两组中差异不显著,表明诱发性和自发性食蟹猴T2DM模型均可作为糖尿病研究较理想的动物模型。因此,通过高能量膳食诱导的食蟹猴糖尿病模型可以替代自发的糖尿病猴,且基因表达量的变化可为疾病的诊断和治疗提供帮助。     

Significant association of interleukin-4 gene intron 3 VNTR polymorphism with susceptibility to knee osteoarthritis

Objective

Interleukin-4 (IL-4) is a strong chondroprotective cytokine and polymorphisms within this gene may be a risk factor for osteoarthritis (OA). We aimed to investigate genotype and allele frequencies of IL-4 gene intron 3 variable number of tandem repeats (VNTR) polymorphism in patients with knee OA in a Turkish population.

Methods

The study included 202 patients with knee OA and 180 healthy controls. Genomic DNA was isolated and IL-4 gene 70 bp VNTR polymorphism determined by using polymerase chain reaction (PCR) with specific primers followed by restriction fragment length polymorphism (RFLP) analysis.

Results

Our result show that there was statistically significant difference between knee OA patients and control group with respect to IL-4 genotype distribution and allele frequencies (p = 0.000, OR: 0.20, 95% CI: 0.10–0.41, OR: 0.22, 95% CI: 0.12–0.42, respectively).

Conclusions

Our findings suggest that there is an association of IL-4 gene intron 3 VNTR polymorphism with susceptibility of a person for development of knee OA. As a result, IL-4 gene intron 3 VNTR polymorphism could be a genetic marker in OA in a Turkish study population. This is the first association study that evaluates the associations between IL-4 gene VNTR polymorphism and knee OA.     

A meta-analysis of association of vitamin D receptor BsmI gene polymorphism with the risk of type 1 diabetes mellitus

Abstract

Association between vitamin D receptor (VDR) BsmI (rs1544410) gene polymorphism and the risk of type 1 diabetes mellitus (T1DM) from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR BsmI gene polymorphism and the risk of T1DM using meta-analysis method. The association studies were identified from PubMed, and Cochrane Library on 1 December 2013, and eligible investigations were included and synthesized using meta-analysis method. Twenty-three reports were recruited into this meta-analysis for the association of VDR BsmI gene polymorphism with T1DM susceptibility. In overall populations, bb genotype was associated with T1DM, but the B allele and BB genotype were not. In Asians and Latino population, B allele and bb genotype were associated with TIDM risk, but BB genotype was not. In Caucasians, VDR BsmI gene polymorphism was not associated with the T1DM risk. In Africans, B allele and BB genotype were associated with T1DM risk, but the bb genotype was not. However, the sample size for Latino population and Africans was small. In conclusion, VDR BsmI B allele, bb genotype was associated with T1DM risk in Asians, and bb genotype was associated with T1DM risk in overall populations. However, more studies should be conducted to confirm it.     

Multivariate meta-analysis of the association of G-protein beta 3 gene (GNB3) haplotypes with cardiovascular phenotypes

The objective of the present study was to review previous investigations on the association of haplotypes in the G-protein β3 subunit (GNB3) gene with representative cardiovascular risk factors/phenotypes: hypertension, overweight, and variation in the systolic and diastolic blood pressures (SBP and DBP, respectively) and as well as body mass index (BMI). A comprehensive literature search was undertaken in Pubmed, Web of Science, EMBASE, Biological Abstracts, LILACS and Google Scholar to identify potentially relevant articles published up to April 2011. Six genetic association studies encompassing 16,068 participants were identified. Individual participant data were obtained for all studies. The three most investigated GNB3 polymorphisms (G-350A, C825T and C1429T) were considered. Expectation–maximization and generalized linear models were employed to estimate haplotypic effects from data with uncertain phase while adjusting for covariates. Study-specific results were combined through a random-effects multivariate meta-analysis. After carefully adjustments for relevant confounding factors, our analysis failed to support a role for GNB3 haplotypes in any of the investigated phenotypes. Sensitivity analyses excluding studies violating Hardy–Weinberg expectations, considering gender-specific effects or more extreme phenotypes (e.g. obesity only) as well as a fixed-effects “pooled” analysis also did not disclose a significant influence of GNB3 haplotypes on cardiovascular phenotypes. We conclude that the previous cumulative evidence does not support the proposal that haplotypes formed by common GNB3 polymorphisms might contribute either to the development of hypertension and obesity, or to the variation in the SBP, DBP and BMI.     

Proteolytic modification of membrane-associated phospholipase C-β by μ-calpain enhances its activation by G-protein βγ subunits in human platelets

Membrane-associated phosphoinositide-phospholipase C (PI-PLC)-β (150 kDa) and its truncated forms (100 kDa and 45 kDa) were purified from human platelets. The 100 kDa PI-PLC-β was found to be activated to a greater extent by brain G-protein βγ subunits compared to the intact 150 kDa enzyme. Furthermore, treatment with μ-calpain of the intact PI-PLC-β (150 kDa) caused a marked augmentation of its activation by βγ subunits. This enhanced PLC activation by βγ subunits was due to truncation by μ-calpain, producing a 100 kDa PI-PLC, but not by another protease,thrombin.     

Association of vitamin D receptor BsmI gene polymorphism with the risk of type 2 diabetes mellitus

Abstract

Relationship between vitamin D receptor (VDR) BsmI (rs1544410) gene polymorphism and the type 2 diabetes mellitus (T2DM) susceptibility is still conflicting at present. This meta-analysis was conducted to assess the association between VDR BsmI gene polymorphism and the risk of T2DM. The association studies were identified from PubMed, and Cochrane Library on 1 January 2014, and eligible investigations were included and synthesized using meta-analysis method. Eleven reports were recruited into this meta-analysis for the association of VDR BsmI gene polymorphism with T2DM susceptibility. In overall populations, B allele, BB genotype and bb genotype were not associated with T2DM risk. VDR BsmI gene polymorphism was also not associated with the T2DM risk in Asians and Caucasians. In conclusion, VDR BsmI gene polymorphism was also not associated with T2DM risk in overall populations, Asians and Caucasians. However, more studies should be conducted to confirm it.