Taurine improves bovine oocyte maturation through recovering mitochondrial dysfunction and oxidative stress-induced apoptosis after microplastics exposure

ABSTRACT: Plastic is widespread in our lives, releasing various microplastics (MP) with toxicity. In recent years, the potential threat of MP on the reproductive system has aroused public concern. Numerous reports have focused on its damage to spermatogenesis. Nevertheless, the toxicity of MP on female reproduction is unclear. Here, we explored this question using bovine oocyte. Through immunofluorescence staining, the results revealed that MP disrupts spindle organization, chromosome alignment, and actin assembly, leading to failed maturation of bovine oocytes. Concurrently, abnormal expression and localization of cortical granules suggest a failure of cytoplasmic maturation. Therefore, embryonic development is affected. Utilizing single-cell transcriptome sequencing technology, we found that MP induced changes in the expression of mitochondrial-related genes, reflecting the damage of MP are mediated by mitochondrial functions. The MP indeed causes oxidative stress, DNA damage, and apoptosis. Taurine is capable of stabilizing cellular antioxidant levels. Our results suggest that taurine can inhibit mitochondrial dysfunction, reversing the failure of oocyte maturation and embryo development following MP exposure. Collectively, we reveal the reproduction toxicity of MP on bovine oocytes and demonstrate the restorative effect of taurine against MP.