Bile Acid Glycochenodeoxycholic Acid (GCDCA) Might Induce the Loss of Plasma Membrane Integrity and the Release of LDH From Ovarian Granulosa Cells, With Implications in PCOS

Altered bile acid profiles in the follicular fluid have been implicated in the pathogenesis of PCOS. Whether certain bile acids modulate the lytic death of ovarian granulosa cells following regulated cell death mechanisms such as pyroptosis and necroptosis in the context of PCOS is unknown. We here treated ovarian granulosa cells (KGN cell line) with different concentrations of three bile acids (GCDCA, TCA, and GCA) in vitro, and then comparatively analyzed the levels of IL-18, LDH, and PGE2 released from these cells by performing ELISA experiments, in order to determine if these bile acids lead to the loss of plasma membrane integrity in granulosa cells. We found that GCDCA (glycochenodeoxycholic acid) at a concentration of 2500 nmol/L significantly increases the release of LDH from KGN cells in vitro. At this concentration, GCDCA treatment resulted in higher than 30% increased release of LDH from granulosa cells. This bile acid-induced increases in LDH release from granulosa cells were specific to GCDCA, because two other bile acids (TCA (taurocholic acid) and GCA (glycocholic acid)) failed to significantly induce the release of LDH from KGN cells. Further mechanistic studies are needed to determine which plasma membrane rupture mechanisms are mostly involved in LDH release from granulosa cells upon GCDCA treatment. For instance, NINJ1-KO and SIGLEC12-KO KGN cells should be used to see in which case GCDCA fails to induce the release of LDH from granulosa cells, and to identify molecular players involved in bile acid-induced lytic cell death-associated membrane rupture in granulosa cells in the context of PCOS.