Dysregulation of microRNAs and their associations with clinical characteristics in recurrent spontaneous abortion patients

Background The aim is to identify the expression of microRNAs in RSA, and to explore whether the dysregulation is related to clinical characteristics. Methods A total of 51 SA villi samples were obtained, among which 31 cases were from patients with recurrent spontaneous abortion (RSA). Six samples (3 case samples and 3 control samples) were randomly selected for high-throughput sequencing. GO and KEGG analyses were performed to analyze gene function and pathways. The expression levels of specific microRNAs were monitored by RT-qPCR. To exclude chromosome karyotype interference, all samples were subjected to whole genome low-depth sequencing technology. Result Thirty-six significantly differentially expressed microRNAs (16 upregulated and 20 downregulated) were detected. The proportion of abnormal chromosome karyotypes was significantly higher in once spontaneous abortion than two or more spontaneous abortions(p < 0.001). The relative expression of miR-182-5p, miR-2110, and miR-320a-5p was not significantly different between the normal and abnormal karyotype. The expression of miR-182-5p and miR-2110 in the villi of the RSA group was significantly lower (0.736 ± 0.139, P < 0.01; 1.874 ± 0.476, P < 0.05) than that in the villi of the control group (1.830 ± 0.480; 2.493 ± 0.582). However, the expression of miR-320a-5p was not significantly different. Similar results for miR-182-5p, miR-2110, and miR-320a-5p expression were found when the primary RSA group was compared with the control group. The expression of miR-320a-5p was significantly upregulated in the high BMI group compared with the normal BMI (P>0.05). Conclusion There are two major findings from this study. MiR-182-5p and miR-2110 are associated with RSA, especially primary RSA. MiR-320a-3p is indirectly involved in RSA through BMI. MiR-182-5p, miR-2110 and miR-320a-5p are potentially involved in the etiology and pathogenesis of RSA.