Hypoxia impairs male reproductive functions via inducing rat Leydig cell ferroptosis under simulated environment at altitude of 5000 m

Aims

Many studies demonstrated reproductive damage in men residing in plains who are exposed to hypoxia at high altitudes. However, little is known about mechanisms between male reproductive impairment and hypobaric hypoxia. Hypoxia is one of the reasons for the imbalance of cellular redox system. Ferroptosis, involved in many pathophysiological progresses, is an oxidative damage-related, iron-dependent regulated cell death, which needs exogenous inducer. In our study, we explored the mechanism between hypoxia and male reproductive dysfunction.

Materials and methods

Here, we established animal model simulating hypobaric hypoxia at an altitude of 5000 m and used ELISA, WB, qPCR, flow cytometry and etc. to obtain different results.

Key findings

The results demonstrated decrease of plasma testosterone (T) and free testosterone (FT) levels under hypoxia, meanwhile there's decline in sperm counts and sperm motility, coupled with increase in sperm malformation rates. Flow cytometry confirmed significant reduction in Leydig cell numbers. Prussian blue staining showed iron depositions in interstitial testis. Features of ferroptosis such as increased MDA (malondialdehyde) levels, reduced solute carrier family 7 member 11 (SLC7A11, xCT) and glutathione peroxidase 4 (GPX4) expression were observed in testis after hypoxic exposure. Further in vitro experiments, we observed that hypoxia suppressed xCT-GPX4 pathway and enhanced cellular ROS accumulation to lead Leydig cell proliferation activity decline.

Significance

Our findings firstly indicated that hypoxia leads to male reproductive dysfunction via inducing Leydig cell ferroptosis. This discovery may offer a potential intervention target for addressing male reproductive injuries under hypoxic conditions.