Exploring the Prognostic Significance of IL10 Variants and Their Mechanistic Regulation in Diabetic Nephropathy

Abstract

IL10 is a very effective anti-inflammatory cytokine. IL10 imbalance is linked to type 2 diabetes mellitus (T2DM) and also to renal hypertrophy, glomerular membrane thickening, and onset of diabetic nephropathy (DN). We aimed to investigate the association of IL10 gene polymorphism (rs1800871T/C, rs1800896A/G) with DN and determine the influence of variants on its expression level and interaction with transcription factors. We genotyped 301 study subjects, comprising 75 DN, 126 T2DM patients, and 100 controls. All were analysed for biochemical assays and genotypic analysis by PCR-RFLP and confirmed by Sanger sequencing. The haplotype analysis was calculated by Chi-square test. mRNA expression and its correlation with variants were assessed by using RT-PCR. Statistical analyses were done by using SPSS and GraphPad software. Screening of transcription factors with IL10 gene variants was performed using the TRANSFAC database, and the variants impact on IL10 molecular interactions was analysed. This study revealed that IL10 gene polymorphism rs1800896 was significantly associated with DN. ‘CG’ and ‘TG’ haplotypes were significantly associated with DN. Expression levels of IL10 were upregulated in DN patients. The genetic correlation study shows that IL10 gene expression was downregulated in the rs1800871 alternate variant genotype (CC) while upregulated in the rs1800896 alternate variant genotype (GG). In silico analyses suggest that the binding affinity of transcription factor CEBPA decreases due to the rs1800871 alternate variant, while the affinity of KLF4 increases in the case of the rs1800896 alternate variant. Our in silico results correlated with IL10 expression analysis in respective patient groups. Overall, our findings highlight the role of IL10 gene polymorphism in DN progression in the North Indian population.