Differential expression of microRNAs in TM3 Leydig cells of mice treated with brain-derived neurotrophic factor

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that can promote the development and proliferation of neurons. BDNF has been found to be involved in male reproduction. Leydig cells in testicular interstitial tissues can secrete testosterone in a luteinizing hormone-dependent manner. We showed that BDNF and its receptor TrkB were expressed in mice TM3 Leydig cells in the present study. Furthermore, BDNF can promote proliferation of mouse TM3 Leydig cells in vitro. Results of microRNA (miRNA) deep sequencing showed that BDNF can alter the expression profile of miRNAs in TM3 Leydig cells. Eighty-three miRNAs were significantly different in the BDNF-treated and control groups (fold change of >2.0 or <0.5, P < 0.05) wherein 40 were upregulated and 43 were downregulated. The expression levels of miR-125a-5p, miR-22-5p, miR-342-59, miR-451a, miR-148a-5p, miR-29b-3p, miR-199b-5p, and miR-145a-5p were further confirmed by quantitative real-time polymerase chain reaction. Bioinformatic analysis revealed that miRNAs regulated a large number of genes with different functions. Pathway analysis indicated that miRNAs participate in the pathways involved in signal transduction, cancer, metabolism, endocrine system, immune system, and nerve system. This study indicated that miRNAs might be involved in the BDNF-regulated cellular functions of Leydig cells.