Association of two ERCC4 tagSNPs with susceptibility to atrophic gastritis and gastric cancer in Chinese

Genetic polymorphisms in excision repair cross-complementing group 4 (ERCC4) may contribute to the risk of cancer development. However, there are few reports regarding to susceptibility to gastric cancer (GC) or its precursor, atrophic gastritis (AG). Thereby, we investigated the association between two tag single nucleotide polymorphisms (tagSNPs) rs6498486 and rs254942, which represents the majority of common SNPs of ERCC4 gene, and the risks of GC and AG development in a sex- and age-matched case–control designed study. We found that rs6498486 polymorphism was associated with a reduced AG risk in total population (for AC vs. AA: OR = 0.69, 95%CI = 0.52–0.94, P = 0.016; for AC/CC vs. AA: OR = 0.68, 95%CI = 0.51–0.92, P = 0.010) as well as in the subpopulation of youngers (age < 60 years) (for AC/CC vs. AA: OR = 0.67, 95%CI = 0.45–0.99, P = 0.048). For the rs254942 polymorphism, compared with the common TT genotype, the genotypes of CT and CT/CC were only observed to reduce AG risk in the subgroups of males (for CT vs. TT: OR = 0.64, 95%CI = 0.45–0.90, P = 0.012; for CT/CC vs. TT: OR = 0.66, 95%CI = 0.47–0.92, P = 0.016) and youngers (for CT vs. TT: OR = 0.72, 95%CI = 0.53–0.97, P = 0.035; for CT/CC vs. TT: OR = 0.74, 95%CI = 0.55–0.99, P = 0.045). However, no significant statistical association of the two SNPs with GC susceptibility was observed in the total population. Only rs6498486 AC and AC/CC genotypes were found to be marginally associated with a reduced GC risk in the subgroup of males (for AC vs. AA: OR = 0.69, 95%CI = 0.49–0.99, P = 0.043; for AC/CC vs. AA: OR = 0.71, 95%CI = 0.50–0.99, P = 0.046). Our findings suggested that the ERCC4 rs6498486 and rs254942 may be associated with AG risk. Further validation of our results in larger populations and additional studies evaluating their molecular function are required.     

SLC2A9rs1014290位点基因多态性与北方汉族地区男性痛风发病的相关性研究

目的:探讨可溶性载体2家族成员9基因(SLC2A9)rs1014290位点的单核苷酸多态性与北方汉族地区男性原发性痛风的发病的相关性。方法:选取404例原发性痛风男性患者和412名健康体检者,分别检测其血清尿酸、血脂、肾功等生化指标,同时提取外周血DNA,应用连接酶检测反应(LDR)法分析其SLC2A9基因rs1014290位点基因型和等位基因频率。结果:痛风组空腹血糖、尿酸(UA)、甘油三酯(TG)、胆固醇(TC)、收缩压、BMI、肌酐(Cr)水平均显著高于对照组,差异有统计学意义(P0.05)。痛风组SLC2A9基因rs1014290位点各基因型频率(CC:12.8%;CT:53.5%;TT:38.7%)与对照组(CC:16.2%;CT:50.9%;TT:32.9%)相比差异有统计学意义(X2=3.978,P=0.041);两组的等位基因频率相比差异无统计学意义(X2=0.314,P=0.496)。结论:SLC2A9基因rs1014290位点多态性可能与我国北方汉族男性原发性痛风的易感性相关,携带TT基因型的个体更易患痛风。     

Common Variants Related to Serum Uric Acid Concentrations Are Associated with Glucose Metabolism and Insulin Secretion in a Chinese Population

Background

Elevated serum uric acid concentration is an independent risk factor and predictor of type 2 diabetes (T2D). Whether the uric acid-associated genes have an impact on T2D remains unclear. We aimed to investigate the effects of the uric acid-associated genes on the risk of T2D as well as glucose metabolism and insulin secretion.

Method

We recruited 2,199 normal glucose tolerance subjects from the Shanghai Diabetes Study I and II and 2,999 T2D patients from the inpatient database of Shanghai Diabetes Institute. Fifteen single nucleotide polymorphisms (SNPs) mapped in or near 11 loci (PDZK1, GCKR, LRP2, SLC2A9, ABCG2, LRRC16A, SLC17A1, SLC17A3, SLC22A11, SLC22A12 and SF1) were genotyped and serum biochemical parameters related to uric acid and T2D were determined.

Results

SF1 rs606458 showed strong association to T2D in both males and females (p = 0.034 and 0.0008). In the males, LRRC16A was associated with 2-h insulin and insulin secretion (p = 0.009 and 0.009). SLC22A11 was correlated with HOMA-B and insulin secretion (p = 0.048 and 0.029). SLC2A9 rs3775948 was associated with 2-h glucose (p = 0.043). In the females, LRP2 rs2544390 and rs1333049 showed correlations with fasting insulin, HOMA-IR and insulin secretion (p = 0.028, 0.033 and 0.052 and p = 0.034, 0.047 and 0.038, respectively). SLC2A9 rs11722228 was correlated with 2-h glucose, 2-h insulin and insulin secretion (p = 0.024, 0.049 and 0.049, respectively).

Conclusions

Our results indicated that the uric acid-associated genes have an impact on the risk of T2D, glucose metabolism and insulin secretion in a Chinese population.     

Longitudinal association between serum uric acid levels and multiterritorial atherosclerosis

Multiterritorial atherosclerosis has dramatically increased annual risk of adverse cardiovascular events than atherosclerotic disease with single‐artery affected. Serum uric acid (SUA) is an important predictor of stroke and atherosclerosis; however, which is supported by few direct evidence based on cohort studies. A prospective cohort study including 2644 North Chinese adults aged ≥40 years was performed in 2010‐2012 to investigate the association between SUA and multiterritorial vascular stenosis. Hyperuricaemia was defined as SUA levels >6 and >7 mg/dL for males and females, respectively. All participants underwent twice transcranial Doppler (TCD) and bilateral carotid duplex ultrasound to evaluate intracranial artery stenosis (ICAS) and extracranial arterial stenosis (ECAS) and peripheral arterial disease (PAD) was determined by ankle‐brachial index (ABI) on January 2010 and January 2012 based on regular health check‐ups. The cumulative incidence of vascular stenosis was significantly higher in subjects with hyperuricaemia than in those without hyperuricaemia (54.1% vs. 34.7%, P < 0.001). The adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for new on‐set vascular stenosis due to hyperuricaemia and a 1‐mg/dL change in SUA level were 1.75 (1.32‐2.31) and 1.29 (1.21‐1.38), respectively. Furthermore, in the gender‐stratified analysis, the association between SUA levels and ICAS was statistically significant in males (OR: 2.02; 95% CI: 1.18‐3.46), but not females (OR: 0.85, 95% CI: 0.41‐1.76, P for interaction: 0.026).     

Effects of a genetic variant rs13266634 in the zinc transporter 8 gene (SLC30A8) on insulin and lipid levels before and after a high-fat mixed macronutrient tolerance test in U.S. adults

BackgroundThe common C-allele of rs13266634 (c.973C>T or p.Arg325Trp) in SLC30A8 (ZNT8) is associated with increased risk of type 2 diabetes. While previous studies have examined the correlation of the variant with insulin and glucose metabolism, the effects of this variant on insulin and lipid responses after a lipid challenge in humans remain elusive. The goal of this study was to determine whether the C-allele had an impact on an individual’s risk to metabolic syndromes in U.S. adults.MethodWe studied the genotypes of rs13266634 in 349 individuals aged between 18 and 65 y with BMI ranging from 18.5 to 45 kg/m². The subjects were evaluated for insulin, glucose, HbA1c, ghrelin, and lipid profiles before and after a high-fat mixed macronutrient tolerance test (MMTT).ResultsWe found that the effects of variants rs13266634 on glucose and lipid metabolism were sex-dimorphic, greater impact on males than on females. Insulin incremental area under the curve (AUC) after MMTT was significantly decreased in men with the CC genotype (p < 0.05). Men with the CC genotype also had the lowest fasting non-esterified fatty acid (NEFA) concentrations. On the other hand, the TT genotype was associated with a slower triglyceride removal from the circulation in men after MMTT. The reduced triglyceride removal was also observed in subjects with BMI ≥ 30 carrying either the heterozygous or homozygous T-allele. Nevertheless, the SNP had little effect on fasting or postprandial blood glucose and cholesterol concentrations.ConclusionWe conclude that the CC genotype negatively affects insulin response after MMTT while the T-allele may negatively influence lipolysis during fasting and postprandial blood triglyceride removal in men and obese subjects, a novel finding in this study.     

Identification of a Hypouricemia Patient with SLC2A9 R380W,A Pathogenic Mutation for Renal Hypouricemia Type 2

Hypouricemia is characterized by low serum uric acid (SUA) levels (≤3.0 mg/dL) with complications such as urolithiasis and exercise-induced acute renal failure. We have previously reported that urate transporter 1 (URAT1/SLC22A12) and glucose transporter 9 (GLUT9/SLC2A9) are causative genes for renal hypouricemia type 1 (RHUC1) and renal hypouricemia type 2 (RHUC2), respectively. In the series of experiments, two families have been revealed to have RHUC2 due to GLUT9 missense mutations R198C or R380W, respectively. Thus far, however, no studies have reported other RHUC2 families or patients with these pathogenic mutations. This study is aimed to find other cases of RHUC2.

We performed mutational analyses of GLUT9 exon 6 (for R198C) and exon 10 (for R380W) in 50 Japanese hypouricemia patients. Patients were analyzed out of a collection of more than 2000 samples from the Japan Multi-Institutional Collaborative Cohort Study (J-MICC Study).

We identified a novel male patient with heterogeneous RHUC2 mutation R380W. The SUA of this hypouricemia patient was 2.6 mg/dL, which is similar to that of our previous report (SUA: 2.7 mg/dL).

This is the second report indicating RHUC2 patient due to GLUT9 mutation R380W. This mutation occurs in highly conserved amino acid motifs and is reported to be an important membrane topology determinant. R380W is a dysfunctional mutation which completely diminishes the urate transport activities of GLUT9. Our study revealed a second hypouricemia patient with GLUT9 R380W, a pathogenic mutation of RHUC2, which may help to expand our understanding of RHUC pathogenesis.     

The effects of interactions between selenium and zinc serum concentration and SEP15 and SLC30A3 gene polymorphisms on memory scores in a population of mature and elderly adults

Memory deficits are common during aging, but little is known about the impact of environmental and genetic variables on memory. The genes SLC30A3 and SEP15 are, respectively, responsible for transporting zinc and selenium, micronutrients that are neuroprotective agents. The aim of this study was to investigate the effect of nutrigenetic interactions on the memory scores of volunteers more than 50 years old. For this cross-sectional study, 240 individuals were enrolled. Micronutrient dosage was determined using atomic absorption spectrophotometry. The SNPs rs5859, rs5854, and rs561104 in SEP15 and rs73924411 and rs11126936 in SLC30A3 were determined by real-time PCR. The evaluations of verbal and visual memory were performed using the Weschler Memory Scale-revised and the Rey’s verbal learning test. A gene versus nutrient interaction was observed for SLC30A3 rs73924411 and zinc concentration. Carriers of the T allele had higher scores for short-term and long-term verbal memories than CC homozygotes only when zinc serum concentration was below the recommended level (p value for the interaction for short-term verbal memory = 0.011, p value for the interaction for long-term verbal memory = 0.039). For SEP15, C carriers of the rs5845 SNP allele had higher verbal learning memory scores than TT homozygotes (0.13 ± 1.13 vs. −1.10 ± 1.20, p = 0.034). Our results suggest the influence of genetic polymorphisms on memory score and identify gene versus nutrient interactions between zinc serum concentration and memory score.     

ABCG2 Dysfunction Increases Serum Uric Acid by Decreased Intestinal Urate Excretion

ATP-binding cassette transporter G2 (ABCG2), also known as breast cancer resistance protein (BCRP), is identified as a high-capacity urate exporter and its dysfunction has an association with serum uric acid (SUA) levels and gout/hyperuricemia risk. However, pathophysiologically important pathway(s) responsible for the ABCG2-mediated urate excretion were unknown. In this study, we investigated how ABCG2 dysfunction affected the urate excretion pathways. First, we revealed that mouse Abcg2 mediates urate transport using the membrane vesicle system. The export process by mouse Abcg2 was ATP-dependent and not saturable under the physiological concentration of urate. Then, we characterized the excretion of urate into urine, bile, and intestinal lumen using in vivo mouse model. SUA of Abcg2-knockout mice was significantly higher than that of control mice. Under this condition, the renal urate excretion was increased in Abcg2-knockout mice, whereas the urate excretion from the intestine was decreased to less than a half. Biliary urate excretion showed no significant difference regardless of Abcg2 genotype. From these results, we estimated the relative contribution of each pathway to total urate excretion; in wild-type mice, the renal excretion pathway contributes approximately two-thirds, the intestinal excretion pathway contributes one-third of the total urate excretion, and the urate excretion into bile is minor. Decreased intestinal excretion could account for the increased SUA of Abcg2-knockout mice. Thus, ABCG2 is suggested to have an important role in extra-renal urate excretion, especially in intestinal excretion. Accordingly, increased SUA in patients with ABCG2 dysfunction could be explained by the decreased excretion of urate from the intestine.     

ABCG2 is a High-Capacity Urate Transporter and its Genetic Impairment Increases Serum Uric Acid Levels in Humans

The ATP-binding cassette, subfamily G, member 2 (ABCG2/BCRP) gene encodes a well-known transporter, which exports various substrates including nucleotide analogs such as 3′-azido-3′-deoxythymidine (AZT). ABCG2 is also located in a gout-susceptibility locus (MIM 138900) on chromosome 4q, and has recently been identified by genome-wide association studies to relate to serum uric acid (SUA) and gout. Becuase urate is structurally similar to nucleotide analogs, we hypothesized that ABCG2 might be a urate exporter. To demonstrate our hypothesis, transport assays were performed with membrane vesicles prepared from ABCG2-overexpressing cells. Transport of estrone-3-sulfate (ES), a typical substrate of ABCG2, is inhibited by urate as well as AZT and ES. ATP-dependent transport of urate was then detected in ABCG2-expressing vesicles but not in control vesicles. Kinetic analysis revealed that ABCG2 is a high-capacity urate transporter that maintained its function even under high-urate concentration. The calculated parameters of ABCG2-mediated transport of urate were a Km of 8.24 ± 1.44 mM and a Vmax of 6.96 ± 0.89 nmol/min per mg of protein. Moreover, the quantitative trait locus (QTL) analysis performed in 739 Japanese individuals revealed that a dysfunctional variant of ABCG2 increased SUA as the number of minor alleles of the variant increased (p = 6.60 × 10^?5). Because ABCG2 is expressed on the apical membrane in several tissues, including kidney, intestine, and liver, these findings indicate that ABCG2, a high-capacity urate exporter, has a physiological role of urate homeostasis in the human body through both renal and extrarenal urate excretion.     

Association between MDR1 C3435T polymorphism and risk of breast cancer

The C3435T (rs1045642) polymorphism, located in multi-drug resistance gene 1 (MDR1), has demonstrated its role in decreasing the P-gp activity level which is related to the carcinogenesis. Many published studies have evaluated the association between the MDR1 C3435T polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the association between MDR1 C3435T polymorphism and risk of breast cancer, we performed a meta-analysis comprised of 10 case–control studies, including 5282 breast cancer cases and 7703 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the association. The overall results indicated that the variant genotypes were associated with a significantly increased risk of breast cancer (TT versus CC: OR = 1.45, 95% CI = 1.14–1.30, TT versus CT/CC: OR = 1.13, 95% CI = 1.04–1.23, TT/CT versus CC: OR = 1.22, 95% CI = 1.02–1.46). Our results suggest that the MDR1 C3435T polymorphism may contribute to individual susceptibility to breast cancer.     

Variant rs2237892 of KCNQ1 Is Potentially Associated with Hypertension and Macrovascular Complications in Type 2 Diabetes Mellitus in A Chinese Han Population

KCNQ1 has been identified as a susceptibility gene of type 2 diabetes mellitus(T2DM) in Asian populations through genome-wide association studies. However, studies on the association between gene polymorphism of KCNQ1 and T2 DM complications remain unclear. To further analyze the association between different alleles at the single nucleotide polymorphism(SNP) rs2237892 within KCNQ1 and TD2 M and its complications, we conducted a case-control study in a Chinese Han population. The C allele of rs2237892 variant contributed to susceptibility to T2DM(odds ratio [OR], 1.45; 95% confidence interval [CI], 1.20–1.75). Genotypes CT(OR, 1.97; 95% CI,1.24–3.15) and CC(OR, 2.49; 95% CI, 1.57–3.95) were associated with an increased risk of T2 DM. Multivariate regression analysis was performed with adjustment of age, gender, and body mass index. We found that systolic blood pressure(P = 0.015), prevalence of hypertension(P = 0.037), and risk of macrovascular disease(OR, 2.10; CI, 1.00–4.45) were significantly higher in subjects with the CC genotype than in the combined population with genotype either CT or     

Serum Uric Acid and Non-Alcoholic Fatty Liver Disease in Non-Diabetic Chinese Men

Increased serum uric acid (SUA) levels may be involved in the development of non-alcoholic fatty liver disease (NAFLD) in men presenting with metabolic syndrome (MetS) and/or insulin resistance. We aimed to determine the independent relationship between SUA and NAFLD in non-diabetic Chinese male population, and to explore the determinants of SUA levels among indexes of adiposity, lipid, and genotypes pertaining to triglycerides metabolism, inflammation, oxidative stress, and SUA concentrations. A total of 1440 men, classified depending on the presence of ultrasonographically detected NAFLD, underwent a complete healthy checkup program. Genotypes were extracted from our previously established genome-wide association study database. After adjusting for age, smoking, drinking, body mass index, homeostasis model assessment of insulin resistance, C-reactive protein, creatinine, alanine aminotransferase (ALT) and components of metabolic syndrome, the odds ratio for NAFLD, comparing the highest with the lowest SUA quartile, was 2.81 (95% confidence interval 1.66–4.76). A stepwise multivariate linear regression analysis (R² = 0.238, P<0.001) retained age, waist circumference, serum creatinine, triglycerides, the Q141K variant in ABCG2 (rs2231142) and NAFLD as significant predictors of SUA levels (all P<0.001). Besides, ALT and Met196Arg variant in TNFRSF1B (rs1061622) additionally associated with SUA among individuls with NAFLD. Our data suggest that in Chinese men, elevated SUA is significantly associated with NAFLD, independent of insulin resistance and other metabolic disorders, such as central obesity or hypertriglyceridemia. Meanwhile, among subjects with NAFLD, index of liver damage, such as elevated ALT combined with genetic susceptibility to inflammation associated with increased SUA levels.     

The alternative serotonin transporter promoter P2 impacts gene function in females with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a gut‐brain disorder in which symptoms are shaped by serotonin acting centrally and peripherally. The serotonin transporter gene SLC6A4 has been implicated in IBS pathophysiology, but the underlying genetic mechanisms remain unclear. We sequenced the alternative P2 promoter driving intestinal SLC6A4 expression and identified single nucleotide polymorphisms (SNPs) that were associated with IBS in a discovery sample. Identified SNPs built different haplotypes, and the tagging SNP rs2020938 seems to associate with constipation‐predominant IBS (IBS‐C) in females. rs2020938 validation was performed in 1978 additional IBS patients and 6,038 controls from eight countries. Meta‐analysis on data from 2,175 IBS patients and 6,128 controls confirmed the association with female IBS‐C. Expression analyses revealed that the P2 promoter drives SLC6A4 expression primarily in the small intestine. Gene reporter assays showed a functional impact of SNPs in the P2 region. In silico analysis of the polymorphic promoter indicated differential expression regulation. Further follow‐up revealed that the major allele of the tagging SNP rs2020938 correlates with differential SLC6A4 expression in the jejunum and with stool consistency, indicating functional relevance. Our data consolidate rs2020938 as a functional SNP associated with IBS‐C risk in females, underlining the relevance of SLC6A4 in IBS pathogenesis.     

Phenotype and genotype relationship of glutathione peroxidase1 (GPx1) and rs 1800668 variant: the homozygote effect on kinetic parameters

GPx1 is one of the most important enzymes involved in oxidative balance so that, we studied the phenotype and genotype relationship of GPx1 activity and rs 1800668 (C/T) site and also evaluated the changes of GPx1 kinetic parameters in the rs 1800668 homozygotes. One hundred fifty eight subjects were recruited after clinical exams. The rs 1800668 (C/T) genotype distribution was identified using RFLP-PCR method. The hemolysate GPx1 activity was spectrophotometrically measured in a reaction coupled with glutathione reductase (GR). The GPx1 enzyme was purified using gel filtration chromatography with Sephacryl S-300 column and, Km(app) was studied in the rs 1800668 TT and CC homozygotes. The results showed that the GPx1 activity is significantly associated to the rs 1800668 (C/T) genotype distribution (P<0.05) so that, the GPx1 activity was high among the CC homozygotes (P<0.03). In addition, Km(app) for TBHP substrate in the TT homozygote (8.48 μM) was higher than the CC homozygote (5.74 μM). We concluded that the C allele within rs 1800668 position is related to the GPx1 activity and may be a potential factor involved in development of inflammatory events.     

Morphometrics of Globodera tabacum tabacum,G. t. virginiae,and G. t. solanacearum (Nemata: Heteroderinae)

A morphometric evaluation of second-stage juveniles (J2), males, females, cysts, and eggs of several isolates of the tobacco cyst nematode (TCN) complex, Globodera tabacum tabacum (GTT), G. t. virginiae (GTV), and G. t. solanacearum (GTS) is presented. Morphometrics of eggs, J2, and males are considerably less variable than of females and cysts. No measurements of eggs and J2 are useful for identification of the three subspecies. Distance from the median bulb and excretory pore to the head end in J2 and males is quite stable. Stylet knob width of males is useful for identifying GTV isolates and tail length in separating males of GTT isolates from GTV and GTS. Body length/width (L/W) ratio of females and cysts discriminates GTT from GTV and GTS; stylet knob width is an auxiliary character for identifying GTV. This subspecies complex has a continuum of values for the other characters. Data suggest a close relationship between GTV and GTS, which also occur in close proximity in Virginia.     

CTLA4CT60 gene polymorphism is not associated with differential susceptibility to pemphigus foliaceus

Pemphigus foliaceus is an organ-specific autoimmune disease characterized by autoantibodies against the extracellular region of desmoglein 1, a protein that mediates intercellular adhesion in desmosomes. Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) is a key negative regulator of the T cell immune response, playing an important role in T cell homeostasis and maintenance of peripheral tolerance. Polymorphisms in the CTLA4 gene have been associated with autoimmune diseases and the functional CT60 single nucleotide polymorphism (rs3087243, also named 6230G > A) has been proposed to be a casual variant in several of these diseases. The aim of this study was to ascertain whether this polymorphism is associated with inter-individual variation in susceptibility to pemphigus foliaceus. The population sample in this case-control association study comprised 248 patient and 367 controls. We did not found a significant association of pemphigus foliaceus with the CT60 variants. We conclude that the CTLA4CT60 polymorphism is not an important factor for pemphigus foliaceus pathogenesis in the population analyzed.     

The effect of folate-related SNPs on clinicopathological features,response to neoadjuvant treatment and survival in pre- and postmenopausal breast cancer patients

This study aimed to investigate the relationship of ten single nucleotide polymorphisms (SNPs) in the MTHFR, MTR, MTRR, DHFR, MTHFD1, TS, RFC1 and DNMT3b genes with cancer survival, therapeutic response to neoadjuvant chemotherapy and clinicopathological characteristics in 300 pre- and postmenopausal breast cancer patients of a Russian Western Siberian population. We found that the MTHFR 677CT genotype as well as combination of MTHFR 677CT and 677TT genotype was related to tumor size and estrogen-positive status in postmenopausal group. The RFC1 80А allele was associated with an increased risk of lymph node metastases among postmenopausal women. The MTHFR 677TT genotype was significantly correlated with a better progression-free survival in premenopausal patients. In contrast, a worse outcome was observed in this group patient with MTHFD1 1958AA genotype. In the multivariate analysis, the MTHFD1 1958AA genotype was identified as an independent prognostic factor for premenopausal breast cancer survival. Our findings provide evidence for associations of breast cancer survival with folate-related SNPs in a population of Western Siberian region of Russia and the MTHFD1 (1958G>A) may have additional prognostic value especially among premenopausal patients.     

SNP exploring in the middle and terminal regions of the IGF-1 gene and association with production and reproduction traits in Holstein cattle

Five primer sets were designed in order to identify single nucleotide polymorphisms (SNPs) in middle and terminal exons (2 to 6) and in some flanking intronic regions of the bovine insulin-like growth factor 1 (IGF-1) gene. Sequencing results of PCR products for 10% of animals showed no variant in exons but a SNP at intron 4 was occurred. Both polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and high resolution melting (HRM) methods were developed to genotype samples. The PCR–RFLP results showed the presence of three fragments on agarose gel for the C allele due to two cleavage sites while two fragments for the T allele were observed. Melting curves of 123 bp fragments in HRM analysis showed a difference between temperature melting (T_m) of two homozygous genotypes as the CC genotypes had higher T_m than the TT genotypes. Melting curve of the CT genotype was different and crossed two parallel patterns of homozygous genotypes. The frequencies of the CC, CT and TT genotypes were 0.6, 0.37 and 0.03, respectively. Also, the estimated allele frequencies were 0.785 and 0.215 for the C and T alleles, respectively. Results showed higher accuracy of the HRM analysis compared to the PCR–RFLP method. Least square means (LSMs) comparison of the different genotypes in the SNP showed significant association with milk fat yield trait in the first lactation and open days after the second calving. The polymorphism did not have a significant effect on other milk production or reproduction traits. It seems that other variants or QTLs known in this region underlie genetic variation in the production and reproduction of dairy cattle.     

Quantitative evaluation of common polymorphism (rs1801282) in the PPARγ2 gene and hypertension susceptibility

The peroxisome proliferator-activated receptor-γ2 (PPARγ2) gene has been implicated in the etiology of hypertension. However, the results have been inconsistent. In this study, a meta-analysis was performed to assess the association of PPARγ2 rs1801282 polymorphism with hypertension risk. Published literature from PubMed, Embase databases, CNKI and Wanfang Data were retrieved. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model. Eight studies (1865 cases and 1416 controls) for rs1801282 polymorphism were identified. The results suggested that rs1801282 polymorphism Ala allele might be protective for hypertension among East Asians (Ala/Ala+Pro/Ala vs. Pro/Pro: OR=0.63, 95%CI 0.46-0.86) but not among Caucasians (Ala/Ala+Pro/Ala vs. Pro/Pro: OR=0.72, 95%CI 0.38-1.38). The results indicated the significant association of PPARγ2 rs1801282 polymorphism with hypertension susceptibility among East Asians.     

Association of MTHFR and PPARγ2 gene polymorphisms in relation to type 2 diabetes mellitus cases among north Indian population

Background

Type 2 diabetes mellitus is a multifactorial and polygenic disease, which is considered as a major life threatening problem all over the world. There has been a worldwide effort in the identification of susceptibility genes for type 2 diabetes mellitus and its complications. At present, adequate data is not available dealing with MTHFR (rs1801133) and PPARγ2 (rs1801282) gene polymorphisms and its association with type 2 diabetes mellitus cases among north Indian populations. Thus, we conceived the need for further studies to investigate MTHFR and PPARγ2 gene polymorphisms and their susceptibility to type 2 diabetes mellitus in north Indian population.

Materials and methods

In this study, a total 175 subjects including 87 type 2 diabetes mellitus cases and 88 controls were enrolled. MTHFR and PPARγ2 gene polymorphisms in the cases and controls were evaluated by polymerase chain reaction and restriction fragment length polymorphism (PCR–RFLP).

Results

The MTHFR gene CC, CT, TT genotype frequencies obtained were 40%, 43%, and 17% in type 2 diabetes mellitus cases and 56%, 29%, and 15% in healthy controls respectively. The OR for CC was 0.54 (95%CI 0.29–0.98, P = 0.041, χ2 = 4.18, power = 0.98), for CT 1.76 (95%CI 0.94–3.30, P = 0.07, χ2 = 3.2, power = 0.96), and for TT 1.2 (95%CI 0.53–2.70, P = 0.66, χ2 = 0.198, power = 0.76). The PPARγ2 gene GG CG, CC genotype frequencies obtained were 28%, 41%, and 31% in cases and 40%, 39%, and 21% in healthy controls respectively. OR for GG was 0.58 (95%CI 0.30–1.09, P = 0.08, χ2 = 2.9, power = 0.96), for CG 1.12 (95%CI 0.61–2.05, P = 0.71, χ2 = 0.137, power = 0.778), and for CC 1.63 (95%CI 0.82–3.23, P = 0.156, χ2 = 2.01, power = 0.92).

Conclusion

It might be recommended that MTHFR CC genotype seems to be a good marker for the early identification of population at risk of type 2 diabetes mellitus. While we have detected significant difference in allelic frequencies of PPARγ2 C (Proline) and G (Alanine), but at genotypic level significant difference was not detected in this case–control study. Further study with larger groups may be required to validate the study.