Peroxisome proliferator-activated receptor gamma (PPARG) (PPARG)

Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated nuclear receptor that serves as a master regulator of adipogenesis and a key modulator of lipid and glucose metabolism [UniProt: P37231]. Upon activation by lipophilic ligands, PPARγ forms a heterodimer with the Retinoid X Receptor (RXR) and binds to specific DNA sequences to regulate the transcription of genes involved in insulin sensitivity and fatty acid storage. It is primarily expressed in adipose tissue but also plays significant roles in immune cells and various epithelial tissues. In the context of iodine metabolism, molecular iodine (I₂) reacts with arachidonic acid to form 6-iodolactone (6-IL), a potent endogenous ligand that activates PPARγ to exert anti-proliferative and pro-apoptotic effects in breast and thyroid cancer cells [PubMed: 17603020, PubMed: 23513013]. Clinically, PPARγ is the primary target for thiazolidinedione drugs, such as pioglitazone, which are used to treat type 2 diabetes by enhancing peripheral insulin sensitivity [StatPearls: NBK551656]. However, therapeutic activation of PPARγ is associated with side effects like weight gain, edema, and increased fracture risk, which limits its broader clinical application [PubMed: 28541544].

Other names

PPAR-gammaPPARGNR1C3Nuclear receptor subfamily 1 group C member 3Glitazone receptor6-iodolactone-activated PPAR-gamma

PPARγ acts as a ligand-activated transcription factor. Upon binding ligands such as 6-iodolactone or thiazolidinediones, it heterodimerizes with the Retinoid X Receptor (RXR) and binds to Peroxisome Proliferator Response Elements (PPREs) in target gene promoters, recruiting coactivators to regulate genes involved in lipid metabolism, glucose homeostasis, and cell differentiation [UniProt: P37231, PubMed: 17603020].