Oxidized high‐density lipoprotein enhances endocrine disorders and ovarian damage in rats

Previous findings have highlighted the association between oxidized high‐density lipoprotein (ox‐HDL) and polycystic ovary syndrome (PCOS) development; however, the underlying mechanism remains unclear. Under such context, the present study aimed to investigate the mechanism underlying the involvement of ox‐HDL in PCOS in relation to the p65/micro‐RNA‐34a (miR‐34a)/FOS axis. PCOS rat models were established with the injection of dehydroepiandrosterone (6 mg/100 g body weight). Both PCOS‐modelled rats and granulosa cells (GCs) were received treatment with ox‐HDL in order to identify its role in PCOS. Next, apoptosis and viability of GCs were detected with the application of TdT‐mediated dUTP Nick‐End Labeling and flow cytometry and Cell counting kit‐8, respectively. A series of assays were performed to determine the interaction among ox‐HDL, p65, miR‐34a, FOS and nuclear factor‐κB (NF‐κB). The results revealed high expression of ox‐HDL in PCOS, and enhanced endocrine disorders and ovarian damage in rats. ox‐HDL promoted apoptosis of GCs and decreased its viability. ox‐HDL activated NF‐κB pathway and induced p65 phosphorylation to promote miR‐34a expression. miR‐34a targeted and inhibited FOS expression. In conclusion, our findings suggested that ox‐HDL promoted the activation of p65 and transcription of miR‐34a, which stimulated apoptosis of GCs and inhibited expression of FOS, resulting in the overall acceleration of PCOS development.