Small RNA sequencing reveals placental miRNAs linked to congenital transmission of Trypanosoma cruzi

Methods

Placental samples from T. cruzi-infected mothers were classified according to congenital transmission status and analyzed by small RNA sequencing. Differential expression was assessed using DESeq2 with Benjamini-Hochberg false discovery rate correction. Nine candidate miRNAs were subsequently assessed by RT-qPCR.

Results: Small RNA sequencing was performed in 31 placental samples, including 13 from transmitting mothers and 18 from non-transmitting mothers. hsa-miR-155-5p was the only miRNA significantly upregulated in placentas from transmitting mothers after multiple-testing correction and was selected as a candidate for further validation. Seven additional miRNAs (hsa-miR-193a-5p, hsa-miR-187-3p, hsa-miR-512-5p, hsa-miR-515-5p, hsa-miR-526a-5p, hsa-miR-99b-3p, and hsa-miR-455-5p) were selected based on nominal p-value, expression abundance, and differences in mean normalized counts between groups.

RT-qPCR assessment in 15 placental samples, including 5 from transmitting mothers and 10 from non-transmitting mothers, showed higher normalized expression of hsa-miR-193a-5p and hsa-miR-187-3p in transmitting mothers.Conclusion: Placental miRNA profiling identified hsa-miR-155-5p, hsa-miR-193a-5p, and hsa-miR-187-3p as candidates for further investigation in congenital transmission of T. cruzi. These findings require confirmation in larger cohorts.