Conserved microRNA mediates heating tolerance in germ cells versus surrounding somatic cells.
RNA Biol. 2019 Jul 05;:
Authors: Wu Y, Wang Y, Liu Q, Zhu LJ, Gao H, Cui M, Liu J, Zhao P, Liu J, Chen L, Wang J, Zeng W, Woodruff TK, Zeng S
Mammalian fertility is reduced during heat exposure in summer, but is regained as temperatures decrease in autumn again. However, the mechanism underlying the phenomenon remain unknown. We investigated heat stress tolerance of germ cells and their surrounding somatic cells, and discovered that microRNA ssc-ca-1 was upregulated after heat stress in cultured porcine granulosa cells (GCs), but not in serum-starved GCs. Ssc-ca-1 inhibited heat shock protein 70 (Hsp70) expression through its 3'- and 5'-UTRs. Although Hsp70 mRNA transcription was induced in GCs by in vivo exposure to heat in summer, ssc-ca-1 inhibited Hsp70 expression. In ovarian cultures, heat stress induced Hsp70 expression in primordial but not in growing follicles; ssc-ca-1 expression did not change in primordial follicles, but increased in growing follicles. Consistently, ssc-ca-1 was present in testicular cells and exhibited the same function as in ovarian cells. It modulated the different Hsp70 expression between spermatogonial stem cells and after Sertoli cells scrotal heat stress. This mechanism is of relevance to mammalian fertility in parts of the world dominated by heat stress associated with global climate change.
PMID: 31276432 [PubMed - as supplied by publisher]