Molybdenum interferes with MMPs/TIMPs expression to reduce the receptivity of porcine endometrial epithelial cells

To investigate the effect of trace element molybdenum (Mo) on the receptivity of porcine endometrial epithelial cells (PEECs) and evaluate Mo toxicity and its potential molecular mechanisms, Mo-treated PEECs models were established by incubating the cells with various concentrations of medium containing Mo (0, 0.005, 0.020, 0.200, and 5 mmol/L MoNa₂O₄·2H₂O). The results showed that Mo disrupted the morphology and ultrastructure of PEECs, triggered blurred cell edges, cell swelling, cell cycle arrest, and increased apoptosis. At the molecular level, Mo treatment activated the TGF-β1/SMAD2 and PI3K/AKT1 pathways, causing a significant increase in matrix metalloproteinase (MMP)-9 and MMP-2 protein expression. Accompanied by markedly increased tissue inhibitors matrix metalloproteinase (TIMP)-2 and decreased TIMP-1, the balance of MMP2/TIMP-2 and MMP-9/TIMP-1 were disrupted. Ultimately, the receptivity of PEECs was destroyed by excessive Mo, which is revealed by the significant decrease of receptive marker molecules, including leukemia inhibitory factor (LIF), integrins β3 (ITGβ3), heparin-binding epidermal growth factor (HB-EGF), and vascular endothelial growth factor (VEGF). To sum up, the current study demonstrated the potential toxicity of Mo to PEECs, indicating reproductive toxicity at high Mo concentrations and suggesting that the content of Mo should be evaluated as a potential risk factor.