Association between genetic variants of microRNA-21 and microRNA-155 and systemic lupus erythematosus: A case-control study from a Chinese population.

Background: Systemic lupus erythematosus (SLE) is a common autoimmune disease, and its pathogenesis remains unclear. The alteration of genetic materials is believed to play a role in SLE development. This study evaluated the association between the genetic variants of microRNA-21 (miR-21) and microRNA-155 (miR-155) and SLE.

Methods: The SNaPshot genotyping method was used to detect the genotypes of selected SNPs in patients and controls. The expression of miR-21 and miR-155 was analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The functional annotation and the biological effects of SNPs were assessed by HaploReg V4.1 and Regulome DB V2.0 software. The Hardy-Weinberg equilibrium test was used to gather statistics, and odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated by logistic regression.

Results: The distribution difference of TA genotype in rs767649 was observed (TA vs. T/T: OR = 0.68, 95%CI, 0.48-0.95, p = 0.026). There was a significant difference in the T/A + A/A (T/A + A/A vs. T/T: OR = 0.68, 95%CI, 0.49-0.94, p = 0.020). A significant difference in T allele distribution was found in the depressed complement of SLE (T vs. A: OR = 0.67, 95%CI, 0.47-0.95, p = 0.026). There were significant differences in genetic variants of rs13137 between the positive and the negative SSB antibodies (Anti-SSB) (T vs. A: OR = 0.67, 95%CI, 0.47-0.95, p = 0.026; T/A + T/T vs. AA: OR = 2.23, 1.18-4.49, p = 0.013). The expression levels of miR-21 and miR-155 were significantly higher in patients than in controls (p < 0.001).

Conclusions: This study provides novel insight that genetic variants of rs767649 and rs13137 are associated with susceptibility to SLE.