Association of miR-146a rs2910164 and miR-149 rs2292832 Variants with Susceptibility to Type 2 Diabetes.

BACKGROUND: The deregulation of miRNAs has been implicated in the pathogenesis of type 2 diabetes (T2D). Single nucleotide polymorphisms (SNPs) located within the miRNA sequence could alter miRNA maturation and expression or change the binding affinity of miRNAs to their target mRNAs. In the present study we aimed to elucidate the possible association between the miR-146a rs2910164 and miR-149 rs2292832 variants with the susceptibility to T2D and its related metabolic traits in an Iranian population.

METHODS: The study population consisted of 183 type 2 diabetic and 192 non-diabetic subjects. The genotyping of the variants was performed by a PCR-RFLP method.

RESULTS: The frequency of the CC genotype of the miR-146a rs2910164 variant was significantly higher in diabetic patients than in controls (15.85% vs. 7.81%, p = 0.043). The results of binary logistic regression suggested that this genotype was significantly associated with T2D (OR of 2.43 (95% CI 1.17 - 5.02, p = 0.016). Moreover, subjects carrying the CC genotype had significantly higher values for diastolic blood pressure, triglycerides, total cholesterol, fasting blood glucose and HbAlc levels compared to individuals having the GG and GC genotypes. Our bioinformatic analyses also showed that the miR-146a sequence is conserved across primate taxa and substituting G to C causes the structural instability of pre-miR-146a by changing the minimum free energy. For the rs2292832 variant, no statistically significant difference was detected for allele or genotype frequencies between T2D and control groups.

CONCLUSIONS: Our findings suggest that miR-146a rs2910164 polymorphism might be associated with T2D and its cardiovascular risk factors in an Iranian population.