The repertoire of testicular extracellular vesicles cargoes and their involvement in inter-compartmental communication required for spermatogenesis

Abstract

Extracellular vesicles (EVs) secreted by the epididymis and prostate are involved in sperm functions and epigenetic inheritance. However, the EVs in the testis remains unexplored. Here, we have established a testis dissociation protocol that allows the isolation of testicular EVs by minimizing the disruption of fragile sperm cells. We showed that testicular EVs were specifically and efficiently uptaken by somatic cells and germ cells in both interstitial space and seminiferous tubules compartments, including the spermatozoa. We profiled the proteome of testicular EVs and probed the cell types that release them. Moreover, we sequenced the small RNAs cargos of testicular EVs and identified sets of small non-coding RNAs that were overlooked in the testis transcriptome. Selected miRNA candidates in testicular EVs were found in sperm RNA payload and demonstrated specific resistance towards ribonuclease A independent of the vesicle membrane. Small molecule inhibition of EVs secretion increased the apoptosis of germ cells via inter-compartmental communication. Together, our study has provided valuable resources on the cargoes of testicular EVs and revealed the inter-compartmental communication that regulates spermatogenesis and may implicate in paternal inheritance.