PPAR gamma2: The main isoform of PPARγ that positively regulates the expression of the chicken Plin1 gene

Perilipin1 (PLIN1) is a major phosphorylated protein that specifically coats the surface of neutral lipid droplets (LDs) in adipocytes and plays a crucial role in regulating the accumulation and hydrolysis of triacylglycerol (TG). Mammalian studies have shown that Plin1 gene transcription is mainly regulated by peroxisome proliferator-activated receptor-gamma (PPARγ), the master regulator of adipogenesis. However, the regulatory mechanism of the chicken Plin1 (cPlin1) gene is poorly understood. The present study aimed to investigate whether Plin1 is regulated by PPARγ in chickens and identify its exact molecular mechanism. Reporter gene and expression assays showed that PPARγ2, but not PPARγ1, activated (P<0.01) the cPlin1 gene promoter. An electrophoretic mobility shift assay and mutational analysis revealed that PPARγ2 bound to a special site in the cPlin1 gene promoter to enhance its expression. In summary, our results show that PPARγ promotes the expression of the cPlin1 gene and that PPARγ2 is the main regulatory isoform.