PPARβ/δ

PPARβ/δ (peroxisome proliferator-activated receptor β/δ) is a ligand-activated nuclear receptor that functions as a transcription factor through heterodimerization with retinoid X receptor (RXR), thereby regulating gene networks involved in cellular differentiation, survival, and energy metabolism^[1]. Mechanistically, PPARβ/δ controls lipid utilization, fatty acid β-oxidation, glucose metabolism, mitochondrial function, and fuel switching, linking nutrient-derived lipid signals to transcriptional programs that maintain metabolic homeostasis^[1][2][3]. Through both ligand-dependent and ligand-independent modes of transcriptional regulation, PPARβ/δ can activate, derepress, or repress target genes, highlighting its complex role in cellular adaptation and metabolic regulation^[4][5]. In disease-related contexts, PPARβ/δ has been implicated in metabolic syndrome, cardiovascular disease, liver metabolic disorders, neuroinflammation, and neurodegeneration, where its regulatory effects on lipid metabolism and inflammatory pathways are considered biologically important^[1][2][6]. Compared with related isoforms, PPARα predominantly regulates fatty acid oxidation in liver and other oxidative tissues, whereas PPARγ primarily controls adipogenesis and insulin sensitivity; in contrast, PPARβ/δ exhibits broader tissue distribution and plays a distinctive role in fuel utilization, mitochondrial biogenesis, and cardiac lipid metabolism^[3][7][1]. For experimental applications, selective agonists such as GW0742 and GW501516 have been widely used to investigate PPARβ/δ-dependent metabolic and inflammatory responses, and PPARβ/δ agonism has been associated with enhanced fatty acid metabolism and altered substrate preference toward lipid utilization in preclinical models^[6][8].