The role of genetic polymorphisms of the Renin-Angiotensin System in renal diseases: A meta-analysis

Structural effect of the H992D/H418D mutation of angiotensin-converting enzyme in the Indian population: implications for health and disease

The Non synonymous SNPs (nsSNPs) of the renin-angiotensin-system (RAS) pathway, unique to the Indian population were investigated in view of its importance as an endocrine system. nsSNPs of the RAS pathway genes were mined from the IndiGenome database. Damaging nsSNPs were predicted using SIFT, PredictSNP, SNP and GO, Snap2 and Protein Variation Effect Analyzer. Loss of function was predicted based on protein stability change using I mutant, PremPS and CONSURF. The structural impact of the nsSNPs was predicted using HOPE and Missense3d followed by modeling, refinement, and energy minimization. Molecular Dynamics studies were carried out using Gromacsv2021.1. 23 Indian nsSNPs of the RAS pathway genes were selected for structural analysis and 8 were predicted to be damaging. Further sequence analysis showed that HEMGH zinc binding motif changes to HEMGD in somatic ACE-C domain (sACE-C) H992D and Testis ACE (tACE) H418D resulted in loss of zinc coordination, which is essential for enzymatic activity in this metalloprotease. There was a loss of internal interactions around the zinc coordination residues in the protein structural network. This was also confirmed by Principal Component Analysis, Free Energy Landscape and residue contact maps. Both mutations lead to broadening of the AngI binding cavity. The H992D mutation in sACE-C is likely to be favorable for cardiovascular health, but may lead to renal abnormalities with secondary impact on the heart. H418D in tACE is potentially associated with male infertility.Communicated by Ramaswamy H. Sarma.

Association of the rs5186 polymorphism of the AGTR1 gene with decreased eGFR in patients with type 2 diabetes from Mexico City

BACKGROUND

Early biomarkers search for Diabetic Kidney Disease (DKD) in patients with Type 2 Diabetes Mellitus (T2DM), as genetic markers to identify vulnerable carriers of the disease even before Glomerular Filtration Rate (GFR) decline or microalbuminuria development, has been relevant during the last few years. The rs5186 (A116C) polymorphism of the Angiotensin II Receptor Type I gene (AGTR1), has been associated to multiple effects of renal injury risk, commonly detected in patients with Diabetes Mellitus (DM). It has been described that rs5186 could have an effect in stability proteins that assemble Angiotensin II Receptor Type I (AT1), modifying its action, which is why it should be considered as a risk factor for Chronic Kidney Disease (CKD), characterized by a GFR progressive reduction. Even though, the association between rs5186 AGTR1 gene polymorphism and DKD in patients with T2DM has been controversial, inconclusive, and even absent. This disputable issue might be as a result of association studies in which many and varied clinical phenotypes included are contemplated as CKD inductors and enhancers. Although, the sample sizes studied in patients with T2DM are undersized and did not have a strict inclusion criteria, lacking of biochemical markers or KDOQI classification, which have hindered its examination.

OBJECTIVE

The aim of our study was to establish an association between rs5186 AGTR1 gene polymorphism and GFR depletion, assessed as a risk factor to DKD development in patients with T2DM.

METHODS

We analyzed 297 not related patients with T2DM, divided into 221 controls (KDOQI 1) and 76 cases (KDOQI 2). Arterial pressure, anthropometric and biochemical parameters were measured. rs5186 of AGTR1 genotyping was performed by TaqMan assay real-time PCR method. Allele and genotype frequencies, and Hardy-Weinberg equilibrium were measured. Normality test for data distribution was analyzed by Shapiro-Wilk test, variable comparison by Student's t-test for continuous variables, and Chi-squared test for categorical variables; ANOVA test was used for mean comparison of more than two groups. Effect of rs5186 to DKD was estimated by multiple heritability adjustment models for risk variables of DKD. Statistical significance was indicated by p<0.05. Data was analyzed using Statistical Package STATA v11 software.

RESULTS

Dominant and Over-dominant models showed a likelihood ratio to GFR depletion of 1.89 (1.05-3.39, p=0.031) and 2.01 (1.08-3.73, p=0.023) in patients with T2DM. Risk factor increased to 2.54 (1.10-5.89) in women in Over-dominant model.

CONCLUSION

In clinical practice, most of nephropathies progress at a slow pace into a total breakdown of renal function, even asymptomatic. This is the first study, reporting that rs5186 polymorphism of AGTR1 gene contribution to GFR depletion, and this could be evaluated as a predisposing factor for DKD in patients with T2DM.

Systematic review and meta-analysis of human genetic variants contributing to COVID-19 susceptibility and severity

The COVID-19 pandemic has spawned global health crisis of unprecedented magnitude, claiming millions of lives and pushing healthcare systems in many countries to the brink. Among several factors that contribute to an increased risk of COVID-19 and progression to exacerbated manifestations, host genetic landscape is increasingly being recognized as a critical determinant of susceptibility/resistance to infection and a prognosticator of clinical outcomes in infected individuals. Recently, several case-control association studies investigated the influence of human gene variants on COVID-19 susceptibility and severity to identify the culpable mutations. However, a comprehensive synthesis of the recent advances in COVID-19 host genetics research was lacking, and the inconsistent findings of the association studies required reliable evaluation of the strength of association with greater statistical power. In this study, we embarked on a systematic search of all possible reports of genetic association with COVID-19 till April 07, 2022, and performed meta-analyses of all the genetic polymorphisms that were examined in at least three studies. After identifying a total of 84 studies that investigated the association of 130 polymorphisms in 61 genes, we performed meta-analyses of all the eligible studies. Seven genetic polymorphisms involving 15,550 cases and 444,007 controls were explored for association with COVID-19 susceptibility, of which, ACE1 I/D rs4646994/rs1799752, APOE rs429358, CCR5 rs333, and IFITM3 rs12252 showed increased risk of infection. Meta-analyses of 11 gene variants involving 6702 patients with severe COVID-19 and 8640 infected individuals with non-severe manifestations revealed statistically significant association of ACE2 rs2285666, ACE2 rs2106809, ACE2 rs2074192, AGTR1 rs5186, and TNFA rs1800629 with COVID-19 severity. Overall, our study presents a synthesis of evidence on all the genetic determinants implicated in COVID-19 to date, and provides evidence of correlation between the above polymorphisms with COVID-19 susceptibility and severity.

Association of AGTR1 A1166C and CYP2C9∗3 Gene Polymorphisms with the Antihypertensive Effect of Valsartan

Background

The differences in the antihypertensive treatment with angiotensin type II receptor blockers (ARBs) may be attributed to polymorphisms in genes involving drug-targeted receptor and drug metabolism. The present study aimed to investigate whether the antihypertensive effect of the ARB drug valsartan was associated with angiotensin II type 1 receptor (AGTR1) gene polymorphism (A1166 C) and cytochrome P450 enzyme 2C9 (CYP2C9) gene polymorphism (CYP2C9∗3).

Methods

281 patients with hypertension who received valsartan monotherapy in the past month were included in this retrospective study. Polymerase chain reaction-melting curve analysis was performed to genotype the AGTR1 and CYP2C9 gene polymorphisms. Based on the systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the time of visit, the patients were divided into well-controlled group (n = 144, SBP/DBP <140/90 mmHg) and poorly controlled group (n = 137, SBP/DBP ≥140/90 mmHg).

Results

Older age, decreased history of drinking, a higher proportion of mild-to-moderate hypertension, lower alanine aminotransferase levels, and higher high-density lipoprotein cholesterol levels were observed in the well-controlled group than the poorly controlled group. Higher frequencies of the C allele and AC + CC genotype of AGTR1 A1166C were detected in the well-controlled than the poorly controlled patients (P = 0.005 and P = 0.006). After adjustment for demographic and environmental factors, the CC + AC genotype of AGTR1 A1166C was markedly linked to better hypertension control with valsartan treatment compared to the AA genotype (odds ratio: 2.836, 95% confidence interval: 1.199–6.705, P = 0.018). No significant difference was observed in the allele or genotype distribution of CYP2C9∗3 polymorphism between well-controlled and poorly controlled patients.

Conclusions

The current data suggested that the AGTR1 A1166 C polymorphism may be associated with the antihypertensive effect of valsartan, and carriers with AC and CC genotypes may have a better antihypertensive efficacy response to valsartan treatment.

The term CAKUT has outlived its usefulness: the case for the prosecution

CAKUT stands for Congenital Anomalies of the Kidney and Urinary Tract, and the acronym first appeared in a review article published in 1998. Since then, CAKUT has become a familiar term encountered in the medical literature, especially in nephrology journals. I reason that the term CAKUT was conceived as not a simple description of various diseases, but more as shorthand for a bold conceptual package that linked the occurrence of diverse types of anatomical malformations with insights from genetic and developmental biology research. Moreover, the angiotensin II receptor type 2 was seen as a paradigmatic molecule in the pathobiology of CAKUT. I contend that the acronym, while appearing as an intellectually good idea at the time it was conceived, has outlived its usefulness. To reach these conclusions, I focus on the complex of research observations that led to the theory behind CAKUT, and then question whether these scientific foundations still stand firm. In addition, it is noted that not all clinicians have adopted the acronym, and I speculate why this is the case. I proceed to demonstrate that there is an incompatibility between the semantic meaning of CAKUT and the diseases for which the term was originally conceived. Instead, I suggest the acronym UTM, standing for Urinary Tract Malformation, is a simpler and less ambiguous one to use. Finally, I contend that the continued use of the acronym is a regressive step for the disciplines of nephrology and urology, taking us back two centuries when all kidney diseases were simply called Bright's disease.

Role of autophagy and evaluation the effects of microRNAs 214, 132, 34c and prorenin receptor in a rat model of focal segmental glomerulosclerosis

AIMS

Focal segmental glomerulosclerosis (FSGS) is the common cause of chronic renal disease worldwide. Although there are many etiologic factors which have common theme of podocyte injury conclusive etiology is not clearly understood. In this study, we aimed to explore the role of autophagy in the pathogenesis of podocyte injury, which is the key point in disease progression, and the roles of intrarenal microRNAs and the prorenin receptor (PRR) in the 5/6 nephrectomy and adriamycin nephropathy models of FSGS.

MAIN METHODS

For experimental FSGS model, 5/6 nephrectomy and adriamycin nephropathy models were created and characterized in adult Sprague Dawley rats. Microarray analysis was performed on FSGS and control groups that was confirmed by q-RT-PCR. Beclin1, LC3B, PRR, ATG7 and ATG5 expression were evaluated by western blotting and immunohistochemistry. Also, Beclin1 and PRR expression were measured by ELISA. Glomerular podocyte isolation was performed and autophagic activity was evaluated in podocytes before and after transfection with miRNA mimic and antagonists.

KEY FINDINGS

Glomerular expression of Beclin1, LC3B, PRR, ATG7 and ATG5 were significantly lower in the 5/6 nephrectomy than adriamycin nephropathy group and in both groups lower when compared to control groups. Western blot results were consistent with immunohistochemical data. Electron microscopy revealed signs of impaired autophagy in FSGS. Autophagic activity decreased significantly after miR-214, miR-132 and miR-34c mimics and increased after transfection with antagonists.

SIGNIFICANCE

These results showed that the role of autophagic activity and decreased expression of PRR in FSGS pathogenesis and miR-34c, miR-132 and miR-214 could be a potential treatment strategy by regulating autophagy.

ACE gene polymorphism and its association with serum erythropoietin and hemoglobin ‎in Iraqi hemodialysis patients

Purpose

To evaluate the frequencies of angiotensin-converting enzyme gene ‎polymorphism in ‎Iraqi hemodialysis patients and to examine the association ‎between this polymorphism and ‎serum erythropoietin and hemoglobin levels.‎.

Methods

In this study, 70 chronic renal failure Iraqi patients on ‎maintenance ‎hemodialysis (patient group) and 20 healthy subjects (control ‎group) were genotyped for ‎angiotensin-converting enzyme gene polymorphism. The distribution of genotype and allele ‎frequencies of this polymorphism in ‎these subjects were also evaluated.‎.

Results

The distribution of angiotensin-converting enzyme genotypes between ‎groups was ‎similar, and the ID genotype was the most frequent, followed by DD and II ‎genotypes (‎50%‎, ‎37%‎, and ‎13%). The control group ‎had a nonsignificant difference in serum ‎erythropoietin levels among different angiotensin-converting enzyme genotypes, ‎while patients with ID and DD genotypes displayed significant ‎elevation in ‎serum erythropoietin with time. No significant differences in hemoglobin ‎levels ‎were observed in patient and control groups. A significant positive correlation ‎was ‎observed between serum erythropoietin and hemoglobin in the control group ‎with different ‎angiotensin-converting enzyme genotypes, while a nonsignificant ‎negative correlation was ‎observed in the patient group throughout the study. ‎.

Conclusions

Chronic kidney disease did not significantly alter angiotensin-converting enzyme ‎genotypes, and angiotensin-converting enzyme gene ‎polymorphism had a significant effect on ‎serum erythropoietin levels and a non‎significant effect on hemoglobin levels. ‎.

Genetic associations between genes in the renin-angiotensin-aldosterone system and renal disease: a systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is defined by abnormalities in kidney structure and/or function present for more than 3 months. Worldwide, both the incidence and prevalence rates of CKD are increasing. The renin-angiotensin-aldosterone system (RAAS) regulates fluid and electrolyte balance through the kidney. RAAS activation is associated with hypertension, which is directly implicated in causation and progression of CKD. RAAS blockade, using drugs targeting individual RAAS mediators and receptors, has proven to be renoprotective.

OBJECTIVES

To assess genomic variants present within RAAS genes, ACE, ACE2, AGT, AGTR1, AGTR2 and REN, for association with CKD.

DESIGN AND DATA SOURCES

A systematic review and meta-analysis of observational research was performed to evaluate the RAAS gene polymorphisms in CKD using both PubMed and Web of Science databases with publication date between the inception of each database and 31 December 2018. Eligible articles included case-control studies of a defined kidney disease and included genotype counts.

ELIGIBILITY CRITERIA

Any paper was removed from the analysis if it was not written in English or Spanish, was a non-human study, was a paediatric study, was not a case-control study, did not have a renal disease phenotype, did not include data for the genes, was a gene expression-based study or had a pharmaceutical drug focus.

RESULTS

A total of 3531 studies were identified, 114 of which met the inclusion criteria. Genetic variants reported in at least three independent publications for populations with the same ethnicity were determined and quantitative analyses performed. Three variants returned significant results in populations with different ethnicities at p<0.05: ACE insertion, AGT rs699-T allele and AGTR1 rs5186-A allele; each variant was associated with a reduced risk of CKD development.

CONCLUSIONS

Further biological pathway and functional analyses of the RAAS gene polymorphisms will help define how variation in components of the RAAS pathway contributes to CKD.

Renin-Angiotensin-Aldosterone System Gene Polymorphisms and Type 2 Diabetic Nephropathy in Asian Populations: An Updated Meta-analysis

BACKGROUND

The association of polymorphisms in the renin-angiotensin-aldosterone system candidate genes, namely Angiotensin-Converting Enzyme (ACE) Insertion/Deletion (I/D), Angiotensinogen (AGT) M235T and Angiotensin II Receptor Type 1 (AGTR1) A1166C with Diabetic Nephropathy (DN) has been studied for decades.

OBJECTIVE

This meta-analysis aimed to assess the updated pooled effects of these polymorphisms with DN among Asian populations with type 2 diabetes mellitus.

METHODS

The PubMed electronic database was searched without duration filter until August 2017 and the reference list of eligible studies was screened. The association of each polymorphism with DN was examined using odds ratio and its 95% confidence interval based on dominant, recessive and allele models. Subgroup analyses were conducted based on region, DN definition and DM duration.

RESULTS

In the main analysis, the ACE I/D (all models) and AGTR1 A1166C (dominant model) showed a significant association with DN. The main analysis of the AGT M235T polymorphism did not yield significant findings. There were significant subgroup differences and indication of significantly higher odds for DN in terms of DM duration (≥10 years) for ACE I/D (all models), AGT M235T (recessive and allele models) and AGTR1 A1166C (recessive model). Significant subgroup differences were also observed for DN definition (advanced DN group) and region (South Asia) for AGTR1 A1166C (recessive model).

CONCLUSION

In the Asian populations, ACE I/D and AGTR1 A1166C may contribute to DN susceptibility in patients with T2DM by different genetic models. However, the role of AGT M235T needs to be further evaluated.

Association between AGTR1 A1166C polymorphism and the susceptibility to diabetic nephropathy: Evidence from a meta-analysis

BACKGROUND

Diabetic nephropathy (DN) is a common complication in patients with diabetic mellitus (DM). Growing evidences have demonstrated that the polymorphisms of angiotensin II receptor type 1 (AGTR1) showed significant association with DN onset, but no consensus has been achieved yet. Therefore, we performed this meta-analysis to combine the findings of previous researches for a more comprehensive conclusion.

METHODS

Eligible publications were identified through electronic databases. The intensity of the correlation between AGTR1 A1166C polymorphism and DN susceptibility was evaluated through calculating pooled odds ratios (ORs) with their 95% confidence intervals (95% CIs). Heterogeneity among included studies was examined with Q test. When P-value less than .05, significant heterogeneity presented, random-effects model was used to calculate the pooled ORs, otherwise, the fixed-effects model was used. Stratification analyses were also performed based on ethnicity and the type of DM.

RESULTS

Seventeen eligible articles were finally included in the present meta-analysis. The analysis results showed that AGTR1 A1166C polymorphism was significantly related to increased risk of DN under CC versus AA (OR = 1.723, 95% CI = 1.123-2.644), CC + AC versus AA (OR = 1.179, 95% CI = 1.004-1.383), CC versus AA + AC (OR = 1.662, 95% CI = 1.112-2.486), and C versus A (OR = 1.208, 95% CI = 1.044-1.397) genetic models. Additionally, a similar result was also found in Asian and T2DM (type 2 diabetic mellitus) groups after subgroup analyses of ethnicity and DM type.

CONCLUSION

AGTR1 A1166C polymorphism may increase the susceptibility to DN, especially in Asians and T2DM population.

Association between angiotensin II receptor type 1 A1166C polymorphism and chronic kidney disease

Studies of the association between angiotensin II receptor type 1 A1166C (AGTR1 A1166C) polymorphism and chronic kidney disease (CKD) risk have yielded conflicting results. We conducted a combined case-control study and meta-analysis to better define this association. The case-control study included 634 end-stage renal disease (ESRD) patients and 739 healthy controls. AGTR1 A1166C genotype was determined using polymerase chain reaction and iPLEX Gold SNP genotyping methods. The meta-analysis included 24 studies found in the PubMed and Cochrane Library databases. Together, the case-control study and meta-analysis included 36 populations (7,918 cases and 6,905 controls). We found no association between the C allele and ESRD (case-control study: OR: 1.02, 95% CI: 0.77–1.37; meta-analysis: OR: 1.07; 95% CI: 0.97–1.18). Co-dominant, dominant, and recessive model results were also not significant. No known environmental factors moderated the effect of AGTR1 A1166C on CKD in our gene-environment interaction analysis. Sensitivity analysis showed an AGTR1 A1166C-CKD association in Indian populations (OR: 1.46, 95% CI: 1.26–1.69), but not in East Asian or Caucasian populations. Additional South Asian studies will be required to confirm the potential role of this polymorphism in CKD.

Familial Analysis of Epistatic and Sex-Dependent Association of Genes of the Renin-Angiotensin-Aldosterone System and Blood Pressure

BACKGROUND

Renin-angiotensin-aldosterone system genes have been inconsistently associated with blood pressure, possibly because of unrecognized influences of sex-dependent genetic effects or gene-gene interactions (epistasis).

METHODS AND RESULTS

We tested association of systolic blood pressure with single-nucleotide polymorphisms (SNPs) at renin (REN), angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin II type 1 receptor (AGTR1), and aldosterone synthase (CYP11B2), including sex-SNP or SNP-SNP interactions. Eighty-eight tagSNPs were tested in 2872 white individuals in 809 pedigrees from the Victorian Family Heart Study using variance components models. Three SNPs (rs8075924 and rs4277404 at ACE and rs12721297 at AGTR1) were individually associated with lower systolic blood pressure with significant (P<0.00076) effect sizes ≈1.7 to 2.5 mm Hg. Sex-specific associations were seen for 3 SNPs in men (rs2468523 and rs2478544 at AGT and rs11658531 at ACE) and 1 SNP in women (rs12451328 at ACE). SNP-SNP interaction was suggested (P<0.005) for 14 SNP pairs, none of which had shown individual association with systolic blood pressure. Four SNP pairs were at the same gene (2 for REN, 1 for AGT, and 1 for AGTR1). The SNP rs3097 at CYP11B2 was represented in 5 separate pairs.

CONCLUSIONS

SNPs at key renin-angiotensin-aldosterone system genes associate with systolic blood pressure individually in both sexes, individually in one sex only and only when combined with another SNP. Analyses that incorporate sex-dependent and epistatic effects could reconcile past inconsistencies and account for some of the missing heritability of blood pressure and are generally relevant to SNP association studies for any phenotype.

Angiotensin II receptor type 1 A1166C modifies the association between angiotensinogen M235T and chronic kidney disease

Single nucleotide polymorphisms (SNPs) in renin-angiotensin system (RAS) genes are associated with RAS imbalance and chronic kidney disease (CKD). We performed a case-control study and meta-analysis to investigate the association between angiotensinogen (AGT) M235T polymorphism and CKD. A total of 634 patients with end-stage renal disease and 739 healthy controls were studied. We also searched PubMed and the Cochrane Library to identify prospective observational studies published before December 2015. We found that the TT and MT genotypes were associated with a higher risk of CKD than the MM genotype (odds ratio [OR]: 3.56; 95% confidence interval [CI]: 1.14-11.16 and OR: 2.93; 95% CI: 0.91-9.46, respectively). Thirty-eight study populations were included in the meta-analysis. The T allele was associated with a higher risk of CKD than the M allele in all populations (OR: 1.19; 95% CI: 1.08-1.32). The OR was 1.33 in Asians (95% CI: 1.06-1.67) and 1.10 in Caucasians (95% CI: 1.02-1.18). Evaluation of gene-gene and gene-environment interactions using epistasis analysis revealed an interaction between AGT M235T and angiotensin II receptor type 1 A1166C in CKD (OR: 0.767; 95% CI: 0.609-0.965). Genetic testing for CKD in high-risk individuals may be an effective strategy for CKD prevention.

Identification of novel molecular signatures of IgA nephropathy through an integrative -omics analysis

IgA nephropathy (IgAN) is the most prevalent among primary glomerular diseases worldwide. Although our understanding of IgAN has advanced significantly, its underlying biology and potential drug targets are still unexplored. We investigated a combinatorial approach for the analysis of IgAN-relevant -omics data, aiming at identification of novel molecular signatures of the disease. Nine published urinary proteomics datasets were collected and the reported differentially expressed proteins in IgAN vs. healthy controls were integrated into known biological pathways. Proteins participating in these pathways were subjected to multi-step assessment, including investigation of IgAN transcriptomics datasets (Nephroseq database), their reported protein-protein interactions (STRING database), kidney tissue expression (Human Protein Atlas) and literature mining. Through this process, from an initial dataset of 232 proteins significantly associated with IgAN, 20 pathways were predicted, yielding 657 proteins for further analysis. Step-wise evaluation highlighted 20 proteins of possibly high relevance to IgAN and/or kidney disease. Experimental validation of 3 predicted relevant proteins, adenylyl cyclase-associated protein 1 (CAP1), SHC-transforming protein 1 (SHC1) and prolylcarboxypeptidase (PRCP) was performed by immunostaining of human kidney sections. Collectively, this study presents an integrative procedure for -omics data exploitation, giving rise to biologically relevant results.

Estimation of the relationship between the polymorphisms of selected genes: ACE, AGTR1, TGFβ1 and GNB3 with the occurrence of primary vesicoureteral reflux

PURPOSE

Etiopathogenesis of VUR is composite and not fully understood. Many data indicate the importance of genetic predisposition. The aim of this study was to establish the relationship of selected polymorphisms: 14094 polymorphism of the ACE, polymorphism rs1800469 of TGFβ-1, rs5443 gene polymorphism of the GNB3 and receptor gene polymorphism rs5186 type 1 AGTR1 with the occurrence of the primary vesicoureteral reflux.

MATERIAL

The study included 190 children: 90 with the primary VUR confirmed with the voiding cystourethrogram and excluded secondary VUR and a control group of 100 children without a history of the diseases of the genitourinary tract.

METHODS

The study was planned in the scheme: "tested case versus control." Genomic DNA was isolated from the leukocytes of peripheral blood samples. The results were statistically analyzed in the Statistica 10 using χ ² test and analysis of the variance Anova.

RESULTS

Any of the four studied polymorphisms showed no difference in the distribution of genotypes between patients with primary vesicoureteral reflux and the control group. In patients with VUR and TT genotype polymorphism rs5443 GNB3 gene, the glomerular filtration rate was significantly higher than in patients with genotype CC or CT.

CONCLUSIONS

(1) No relationship was found between the studied polymorphisms (14094 ACE gene, rs1800469 gene TGFβ1, GNB3 gene rs5443, rs5186 AGTR1 gene) and the occurrence of primary vesicoureteral reflux. (2) TT genotype polymorphism rs5443 GNB3 gene may be a protective factor for the improved renal function in patients with primary vesicoureteral reflux in patients with genotype CC or CT.

Genetic Considerations in Pediatric Chronic Kidney Disease

Chronic kidney disease (CKD) in children is an irreversible process that, in some cases, may lead to end-stage renal disease. The majority of children with CKD have a congenital disorder of the kidney or urological tract arising from birth. There is strong evidence for both a genetic and epigenetic component to progression of CKD. Utilization of gene-mapping strategies, ranging from genome-wide association studies to single-nucleotide polymorphism analysis, serves to identify potential genetic variants that may lend to disease variation. Genome-wide association studies evaluating population-based data have identified different loci associated with CKD progression. Analysis of single-nucleotide polymorphisms on an individual level suggests that secondary systemic sequelae of CKD are closely related to dysfunction of the cardiovascular-inflammatory axis and may lead to advanced cardiovascular disease through abnormal vascular calcification and activation of the renin-angiotensin system. Similarly, genetic variants affecting cytokine control, fibrosis, and parenchymal development may modulate CKD through development and acceleration of renal interstitial fibrosis. Epigenetic studies evaluate modification of the genome through DNA methylation, histone modification, or RNA interference, which may be directly influenced by external or environmental factors directing genomic expression. Lastly, improved understanding of the genetic and epigenetic contribution to CKD progression may allow providers to identify a population at accelerated risk for disease progression and apply novel therapies targeted at the genetic mechanism of disease.

Systematic Review by Multivariate Meta-analyses on the Possible Role of Tumor Necrosis Factor-α Gene Polymorphisms in Association with Ischemic Stroke

A number of studies have investigated the association between tumor necrosis factor (TNF)-α gene polymorphisms and ischemic stroke susceptibility. However, results of different individual studies are often inconsistent. To provide a more robust evaluation of the association between polymorphisms of the TNF-α gene and ischemic stroke risk, we performed a systematic review with multivariate meta-analyses. PubMed, Embase, CNKI, and WanFang databases were searched up to December 20, 2014. Two reviewers independently extracted information and assessed quality of included studies after all the eligible studies were identified. Afterward, multivariate meta-analyses were performed using Stata 13. The estimation of polymorphisms and disease risk was presented by odds ratios (ORs) and corresponding 95 % confidence intervals (CIs). Forty-nine eligible case-control studies from 25 articles that explored the association between 10 TNF-α polymorphisms and ischemic stroke were indentified from aforementioned databases. The results of multivariate meta-analysis showed a significant association between -238G/A polymorphism (4760 patients and 4389 controls) and ischemic stroke risk in heterozygotes compared with wild genotype (AG vs. GG: OR 1.44, 95 % CI 1.11-1.87; AA vs. GG: OR 1.98, 95 % CI 0.73-5.40). No significant association of -308G/A, -857C/T, and -1031T/C polymorphisms was observed. The results of stratification analyses of -238G/A polymorphism showed that the AG genotype only increased the risk of ischemic stroke in Asians compared to GG genotype. No additional significant association was observed in this study. In conclusion, the present systematic review and meta-analysis support a prominent role of the TNF-α -238G/A polymorphism in the risk of ischemic stroke in Asian adults only, but do not support the role of -308G/A, -857C/T, -1031T/C, -244G/A, -367G/A, -646G/A, -806C/T, -863C/A, and +448G/A in the risk of ischemic stroke. The current evidence warrants further studies with high quality and large sample size to confirm.

Association of atrial fibrillation with gene polymorphisms of connexin 40 and angiotensin II receptor type 1 in Chongming adults of Shanghai

OBJECTIVE

To characterized the gene polymorphisms of connexin 40 (cx40) and angiotensin II receptor type 1 (AT1R) in Chongming adults with atrial fibrillation (AF) and to explore their relationships with AF.

METHODS

82 patients with AF, and 82 subjects without AF were enrolled. Polymorphisms of cx40 G-44A and AT1 A1166C were detected. Moreover, several samples were randomly selected to validate the gene polymorphisms of cx40 and AT1.

RESULTS

Genotypes AA, AG and GG of cx40 G-44A were found in both AF patients and controls. The frequencies of genotypes AA, AG and GG were 39%, 29% and 32%, respectively, in AF patients and 31%, 35% and 34%, respectively in controls. The frequencies of alleles A and G were 54% and 46%, respectively in AF patients and 48% and 52%, respectively, in controls (P < 0.05). The risk for AF in patients with allele A increased 1.31 times (OR = 1.31, P < 0.05). The frequencies of genotypes AA, AC and CC were 88%, 8% and 4%, respectively in AF patients and 93%, 6% and 1%, respectively in controls. The frequencies of alleles A and C were 92% and 8%, respectively in AF patients and 96% and 4%, respectively in controls (P < 0.05). More AF patients had allele C as compared to controls. The risk for AF increased by 1.43 times in patients with allele C (OR = 1.43, P < 0.05).

CONCLUSION

There were relationships between gene polymorphisms of cx40 and AT1 and AF in Chongming adults. Allele A of cx40 G-44A and allele C of AT1 A1166C significantly increase the risk for AF.