The influence of menadione-induced oxidative stress on progestagen production and transcriptome of in vitro luteinized follicular cells of domestic cats.

Menadione is a naphthoquinone compound that can trigger oxidative stress in cells by superoxide anion generation. The effects of menadione-induced oxidative stress were investigated in a 3D luteal-like cell culture model of domestic cats. Spheroids of luteinized follicular cells were incubated for 24 h with 0 (control, C), 1 (M-1), or 5 (M-5) μM menadione. Menadione at 1 μM did not significantly alter progestagen secretion; however a concentration of 5 μM decreased secretion compared with the control. RNA sequencing revealed 6 upregulated and 49 downregulated genes in M-1 compared with C, whereas 29 genes were upregulated and 25 were downregulated in M-5 compared with C. No clear transcriptional evidence of an oxidative stress response was observed in M-1, with the upregulated genes primarily associated with signalling-related processes. In contrast, 5 μM menadione induced a transcriptional response consistent with oxidative stress, including increased expression of NQO1, TXNRD1, and SRXN1. All three genes encode antioxidant enzymes known to be regulated by the cytoprotective transcription factor NRF2. NQO1 may contribute directly to menadione detoxification, whereas the interaction of menadione with TXNRD1 can result in ROS generation. Overall, these findings demonstrate a concentration-dependent response of a domestic cat luteal-like model to menadione, affecting both progestagen secretion and gene expression, and provide new insights into the effects of oxidative stress on luteal function in the domestic cat.