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Background: Several polymorphisms in the angiotensin-converting enzyme (ACE) and ACE2 genes are associated with the development of end-stage renal disease (ESRD). Certain genetic polymorphisms may modify the deleterious effects of environmental factors such as cigarette smoking and may also modify the inherited risk. We investigated the association of six ACE and ACE2 polymorphisms with ESRD to determine whether a relationship exists between gene-smoking interactions and ESRD., Materials and Methods: We performed a case-control association study and genotyped 683 ESRD patients and 653 healthy controls. All subjects were genotyped for ACE (I/D, G2350A and A-240T) and ACE2 (G8790A, A1075G and G16854C) gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis., Results: Significant associations were observed between ACE I/D and G2350A polymorphisms and ESRD. There was no difference in ACE2 genotype distribution between ESRD patients and healthy controls. Haplotype analysis showed that DAA and DAT haplotypes were risk factors for ESRD. Moreover, a gene-environment interaction was observed between ACE I/D polymorphism and cigarette smoking., Conclusion: ACE I/D and ACE G2350A polymorphisms were associated with the development of ESRD. The interaction between ACE I/D polymorphism and smoking is also associated with an enhanced risk of ESRD., (© The Author(s) 2013.)

Background: Knee osteoarthritis (OA) is a complex disease involving both biomechanical and metabolic factors that alter the tissue homeostasis of articular cartilage and subchondral bone. The catabolic activities of extracellular matrix degradation products, especially fibronectin (FN), have been implicated in mediating cartilage degradation. Chondrocytes express several members of the integrin family which can serve as receptors for FN including integrins α5β1, αvβ3, and αvβ5. The purpose of this study was to determine whether polymorphisms in the FN (FN-1) and integrin genes are markers of susceptibility to, or severity of, knee OA in a Han Chinese population., Methods: Two independent case-control studies were conducted on 928 patients with knee OA and 693 healthy controls. Ten single nucleotide polymorphisms (SNPs) of FN-1 and the integrin αV gene (ITGAV) were detected using the ABI 7500 real-time PCR system., Results: The AT heterozygote in FN-1 (rs940739A/T) was found to be significantly associated with knee OA (adjusted OR = 1.44; 95% CI = 1.16-1.80) in both stages of the study. FN-1 rs6725958C/A and ITGAV rs10174098A/G SNPs were only associated with knee OA when both study groups were combined. Stratifying the participants by Kellgren-Lawrence (KL) score identified significant differences in the FN-1 rs6725958C/A and rs940739 A/T genotypes between patients with grade 4 OA and controls. Haplotype analyses revealed that TGA and TAA were associated with a higher risk of OA, and that TAG conferred a lower risk of knee OA in the combined population., Conclusions: Our study suggests that the FN-1 rs940739A/T polymorphism may be an important risk factor of genetic susceptibility to knee OA in the Han Chinese population.

Chronic kidney disease (CKD) is highly prevalent in Taiwan and an increasing number of patients are affected, with a high risk of progression to end-stage renal disease and huge medical expenses. It has been predicted that the presence of hypertension increases with decreasing renal function due to a decrease in sodium excretion and activation of the renin-angiotensin system (RAS). The aim of this study was to investigate the influence of genetic variants of the RAS gene on CKD. We performed a case control association study and genotyped 135 CKD patients and 270 healthy controls among Han Chinese in Taiwan. All subjects were genotyped for angiotensinogen (AGT-M235T, T174M, A-20C), angiotensin-I converting enzyme (ACE-A2350G) and angiotensin II type 1 receptor (AGTR1-A1166C, C573T, C-521T) polymorphisms of RAS genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Significant associations were observed in ACE-A2350G and AGTR1-C573T polymorphism between CKD patients and controls. In regard to ACE-A2350G, compared with the AA genotype the GG genotype protected against CKD (adjusted odds ratio [OR] = 0.34; p = 0.01). In regard to AGTR1-C573T, the CT genotype was a risk for CKD compared with the CC genotype (adjusted OR = 1.82; p = 0.03). We conclude that ACE-A2350G and AGTR1-C573T polymorphisms are likely candidate determinants of CKD.

Chronic kidney disease (CKD) is increasingly recognized as a global public health problem. As inflammatory processes and genetic factors are involved in the pathogenesis of CKD, we have investigated the potential genetic contribution of Toll-like receptor (TLR) gene polymorphisms in CKD. In a case-control association study, 149 CKD patients and 429 healthy controls were genotyped by real-time polymerase chain reaction. CKD patients were defined as kidney damage (albuminuria, proteinuria or hematuria) or glomerular filtration rate < 60 ml/min/1.73 m(2) for 3 months or more. Single nucleotide polymorphisms (SNPs) at TLR-2 G2408A, TLR-4 A12874G and C13174T, and TLR-9 T-1237C, T-1486C, and G1635A were assessed, and linkage disequilibrium calculations and haplotype association analysis were undertaken. The functions of TLR-9 have been documented to recognize the viral and bacterial CpG DNA sequences, whereas detects microbe-derived peptidoglycan and lipopeptides and TLR-4 binds lipopolysaccharides. SNPs within the TLR genes may influence promoter activity, mRNA conformation and subcellular localization, and/or protein structure and function. Our results show that only the TLR-9 T-1237C and G1635A gene polymorphisms demonstrate an association with CKD (p = 0.002 and p = 0.04, respectively). The TLR-9 TCA haplotype at T-1237C, T-1486C, and G1635A was associated with a lower risk of CKD, whereas the TTA haplotype was associated with a higher risk of CKD. In the Han Chinese population, those who carry the C and A alleles at SNPs T-1237C and G1635A in the TLR-9 gene appear to be more susceptible to the development of CKD.