Regulation of PPARγ in the development of early sheep embryos in vitro

Lipid metabolism plays an important role in the regulation of early embryonic development in mammals. However, the effect of lipid metabolism mediated by peroxisome proliferator-activated receptor γ (PPARγ) on the early embryonic development of sheep remains unclear. In this study, rosiglitazone (RSG), a PPARγ activator, was added to the in vitro embryo culture (IVC) medium to regulate the continuous expression of PPARγ. This study aimed to evaluate PPARγ expression during early embryonic development in sheep as well as its effects on lipid deposition, reactive oxygen species (ROS) and glutathione (GSH) levels, apoptosis and lipid metabolism-related gene expression, and embryonic development. PPARγ was not detected at 2-cell, 4-cell, 8-cell, and morula stage, while widely expressed with obvious nuclear expression features in blastocysts. Notably, treatment with 5 μM RSG in sheep parthenogenetic activated (PA) embryos significantly increased the blastocyst rate, lipid content, and GSH levels, while decreasing ROS levels. Further analysis revealed that RSG treatment upregulated the expression levels of antioxidant genes (SOD2 and CAT), anti-apoptotic gene (BCL2), and lipid metabolism-related genes (SCD-1, CD36, PLIN2, FABP3, and FABP4). Taken together, these results suggest that PPARγ plays a vital role in promoting embryonic development by enhancing lipid metabolism and reducing oxidative stress.