CDX2 alleviates hypoxia‐induced apoptosis and oxidative stress in spermatogenic cells through suppression of reactive oxygen species‐mediated Wnt/β‐catenin pathway

Abstract

AbstractHypoxia‐induced apoptosis and oxidative stress in spermatogenic cells are considered to be important factors leading to male infertility. It was reported that CDX2 expression was downregulated in hypoxia‐stimulated spermatogenic cells. However, the effects of CDX2 on hypoxia‐induced apoptosis and oxidative stress in spermatogenic cells are still unknown. This study aimed to explore the roles of CDX2 in hypoxia‐induced injury of spermatogenic cells, as well as its mechanism of action. Spermatogenic cells were cultured under 1% oxygen for 48 h to established hypoxia damage model. Reactive oxygen species (ROS) generation was determined using 2′,7′‐dichlorofluorescein diacetate assay. Apoptosis was assessed using flow cytometry. Enzyme‐linked immunosorbent assay was used to evaluate oxidative stress markers, including malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidases (GSH‐Px). Protein levels were detected using western blotting. Hypoxia exposure induced increase in ROS generation, apoptosis rate, and oxidative stress in spermatogenic cells. ROS scavenger inhibited hypoxia‐induced apoptosis, oxidative stress, and Wnt/β‐catenin pathway activation. Hypoxia exposure induced CDX2 downregulation. CDX2 overexpression suppressed hypoxia‐induced ROS generation, apoptosis rate, oxidative stress, and Wnt/β‐catenin pathway activation. Moreover, CDX2 knockdown restores the inhibitory effects of si‐β‐catenin or NAC on hypoxia‐induced activation of the Wnt/β‐catenin pathway, apoptosis, and oxidative stress. In conclusion, our study suggests that CDX2 overexpression alleviates hypoxia‐induced apoptosis and oxidative stress by suppression of ROS‐mediated Wnt/β‐catenin pathway in spermatogenic cells.