Cellular and Transcriptional Adaptation of Bovine Granulosa Cells Under Ethanol-Induced Stress In Vitro.

Abstract

Granulosa cells (GCs) are the major cellular component in a follicular microenvironment and play an indispensable role in ovarian function. This study was conducted to investigate the effects of ethanol exposure on the cellular and transcriptional changes of ovarian GCs. For this purpose, bovine GCs were exposed to different concentrations of ethanol (0, 50, 100, 200, 500 and 1000) to mimic the effects of alcohol in in vitro. Subsequently, 100 and 1000mM concentrations were discarded from further experiments, as 100mM was not different from 50mM, and 1000mM was supertoxic to the cells. The results showed that there was a gradual loss of cell viability with the increase of the ethanol concentration, i.e. lowest viability was observed at the highest concentration (1000mM), which is further supported by cell proliferation assay. Mitochondrial activity decreased significantly at higher concentrations. The expression of NRF2 decreased significantly (P<0.05) in ethanol-exposed cells compared with the cells in the control group at the 6-h time point, whereas the expression was increased in 500mM concentration at the 24-h time point. The expression of antioxidant genes, downstream to Nrf2-pathway activation, showed that overall expression pattern similar to NRF2. The result of this study prompted us to postulate that ethanol exposure decreases the ability of GCs to handle stress by downregulating the expression of genes involved in Nrf2-pathway.