Analysis of the characteristics of microRNA expression profiles and reproductive regulation-mediated signalling pathways in testicular sertoli derived sEVs from Leizhou goats.

This study focused on the tropical-adapted Leizhou black goat to analyse the miRNA expression profile characteristics of testicular Sertoli cells (SCs) and SC-derived small extracellular vesicles (SC-sEVs) and the potential signalling pathways involved in reproductive regulation. SCs and SC-sEVs were isolated and purified, and their characteristics were verified through morphology, particle size analysis, and identification of marker proteins. Illumina high-throughput sequencing was used to analyse the miRNA expression profile of SC-sEVs. Target genes of differentially expressed miRNAs were predicted using TargetScan (v7.0) and miRanda (v3.3a) and their biological functions were analysed via GO and KEGG pathway enrichment. The results indicated that the SCs and their sEVs were successfully isolated with high purity. Small RNA sequencing of sEVs (Illumina NovaSeq, n = 3) revealed 387 known miRNAs and 52 novel miRNAs. miRNAs with 19-nt lengths were predominant, and the top 20 most abundant miRNAs accounted for 61% of total reads. A total of 9176 target genes were significantly enriched in the Hippo (p = 1.3 × 10− 4), TGF-β (p = 3.9 × 10− 4), MAPK, JAK-STAT, Wnt, and cAMP signalling pathways. This study comprehensively characterised the miRNA expression profile of goat SC-sEVs and confirmed that the miRNAs enriched in SC-sEVs could regulate reproduction-related pathways through target genes, thereby contributing to the maintenance of the spermatogenic microenvironment.