Wei Y, et al. The Journal of Steroid Biochemistry and Molecular Biology, 2022, 221, 106115.
Buffalo follicular atresia, a process where ovarian follicles degenerate and fail to develop, has significant implications for animal reproduction and agricultural productivity. Recent research reveals a critical role for glycodeoxycholic acid (GDCA), a conjugated bile acid, in this process.
Bile acids, though abundant in mammalian follicular fluid, are not synthesized in the follicles themselves. Instead, they are transported from the bloodstream into the follicular environment, as evidenced by the expression of bile acid transporters in ovarian tissues and the absence of rate-limiting enzymes required for bile acid synthesis. The study compared healthy follicles (HF) and atretic follicles (AF), finding thirteen differential bile acid subspecies between them. Notably, free bile acids were significantly down-regulated, while conjugated forms, such as GDCA, were up-regulated in AF.
The study's targeted analysis identified GDCA as a key mediator in promoting follicular granulosa cell apoptosis and reducing steroid hormone production. This dual action contributes to follicular atresia, suggesting that the accumulation of GDCA in AF is a significant factor in accelerating this degenerative process. The upregulation of conjugated bile acids, particularly GDCA, in atretic conditions implies a potential feedback mechanism where increased GDCA levels exacerbate atresia by fostering cellular apoptosis and hormonal disruption.