Functional miR29a gene polymorphism enhanced the risk of chronic kidney disease in an Iranian population: A preliminary case-control study and bioinformatics analyses

Association of a single nucleotide polymorphism in SOD2 with susceptibility for the development of diabetic nephropathy in patients with type 2 diabetes: A Saudi population study

INTRODUCTION

One of the complications of diabetes mellitus (DM) is diabetic nephropathy (DN), which plays a significant role in the progression of end-stage renal disease. Oxidative stress is implicated in DN pathogenesis, and genetic variations in antioxidant enzymes such as superoxide dismutase 2 (SOD2) and catalase (CAT) may contribute to the susceptibility. This study aimed to investigate the potential association between single nucleotide polymorphisms (SNPs) in antioxidant enzymes, specifically SOD2 rs4880 and CAT rs769217, and the risk of T2D and susceptibility to DN within the Saudi population.

METHODS

This case-control study included 150 participants, comprising 50 patients with T2D without DN (group 1), 50 patients with T2D with DN (group 2), and 50 healthy participants (group 3). The samples were genotyped using real-time PCR for SOD2 rs4880 and CAT rs769217 SNPs. Sanger sequencing was used for validation. Statistical analyses were performed to explore associations between these SNPs and T2D with or without DN.

RESULTS

No significant difference was observed in CAT rs769217 expression between the groups. However, a significant difference was observed in SOD2 rs4880 expression between the healthy controls and patients with T2D with DN (p = .028). Furthermore, SOD2 rs4880 was associated with approximately threefold increased risk of DN in patients with T2D compared to that in healthy participants (odds ratio [OR] = 2.99 [1.31-6.83]). Validation through Sanger sequencing further confirmed these findings.

CONCLUSIONS

The findings of this study provide evidence that SOD2 rs4880 SNP may contribute to inadequate defence by the antioxidant enzyme, SOD2, against DM-induced oxidative stress and thus cause DN in Saudi patients with T2D. Therefore, SOD2 rs4880 may serve as a predictive marker to prevent the development and progression of DN in patients with T2D.

Coding Variants of the FMO3 Gene Are Associated with the Risk of Chronic Kidney Disease: A Case-Control Study

Background

Chronic kidney disease (CKD) is a global health concern involving roughly one-tenth of developed countries' populations. The flavin-containing dimethylaniline monooxygenase 3 (FMO3) gene encodes an enzyme that catalyzes trimethylamine N-oxide (TMAO), a toxin in CKD sufferers. This preliminary study aims to evaluate the association between coding region variations of FMO3, rs2266782G/A (E158K), rs2266780A/G (E308G), and rs1736557G/A (V257M), and the susceptibility to CKD.

Methods

A total of 356 participants were enrolled, including 157 patients diagnosed with CKD and 199 age-matched healthy individuals. Genotyping of FMO3 gene variations was performed via PCR-RFLP and ARMS-PCR methods.

Results

Our findings revealed a significant association between rs2266780A/G and rs1736557G/A and CKD under different genetic models. Compared to the GGG haplotype of rs2266782/rs1736557/rs2266780, the GAG, GAA, AAG, and AAA haplotype combinations conferred an increased risk of CKD in our population. Interaction analysis revealed that some genotype combinations, including GA/AA/AA, AA/AA/AA, GA/AA/GA, and GG/AG/AA, dramatically increased CKD risk in the Iranian population. No correlation was found between FMO3 polymorphisms and CKD stages.

Discussion

These observations highlight the potential impact of coding variants of the FMO3 gene on the onset of CKD. Further investigations into expanded populations and diverse races are needed to confirm our findings.