Exposure to ochratoxin a induces organelle damage during porcine oocyte maturation.

Introduction: Ochratoxin A is a toxic mycotoxin produced by fungi, which is commonly detected in contaminated cereals and animal feeds. It exhibits nephrotoxicity, hepatotoxicity, genotoxicity, immunotoxicity, and reproductive toxicity. Methods: In the present study, we investigated the adverse effects of ochratoxin A on organelle distribution using a porcine oocyte model. Results: We demonstrated that in vitro exposure to ochratoxin A inhibited cumulus cell expansion and polar body extrusion in oocytes. Ochratoxin A reduced cortical endoplasmic reticulum distribution and increased GRP78 expression, indicating the induction of endoplasmic reticulum stress. In contrast, the Golgi apparatus exhibited abnormal accumulation, accompanied by decreased Rab7 expression and aberrant localization, suggesting impaired vesicular transport. Similarly, lysosomes accumulated in the cytoplasm of porcine oocytes following ochratoxin A treatment. We also found that mitochondrial function was disrupted, as evidenced by reduced ATP production and aberrant mitochondrial membrane potential. Conclusion: Taken together, these results indicate that ochratoxin A impairs organelle distribution, induces endoplasmic reticulum stress, and causes vesicular transport defects during porcine oocyte maturation.