Phytanic acid-derived peroxisomal lipid metabolism in porcine oocytes

Lipid metabolism plays an important role in oocyte maturation. The peroxisome is the fundamental mediator for this mechanism. In this study, we investigated the peroxisomal lipid metabolism in porcine oocytes. Phytanic acid (PA) was chosen as an activator of alpha-oxidation in peroxisomes. Oocyte maturation, embryo development, immunocytochemistry of peroxisomal lipid activities, and staining of mitochondrial potentials were assessed. We found that 40 μM PA not only increased porcine oocyte maturation and embryonic development, but also upregulated the expression of genes and proteins related to activities of the peroxisomal lipid metabolism (PHYH, PEX19, and PEX subfamilies) and mitochondrial potentials (NRF1 and PGC1α). Moreover, PA upregulated the lipid droplet and fatty acid content in the oocytes. Moreover, mitochondria were activated and the mitochondrial membrane potential was increased after PA treatment, resulting in the production of more ATPs in the oocytes. Our findings suggest that the degradation of PA via alpha-oxidation in the peroxisome may potentiate oocyte maturation processes, peroxisomal lipid oxidation, and mitochondria activities.