Peroxisome proliferator-activated receptors β/δ: emerging roles for a previously neglected third family member

Purpose of review Peroxisome proliferator-activated receptors α, β/δ and γ are members of the nuclear receptor superfamily. They mediate the effects of fatty acids and their derivatives at the transcriptional level, and are considered to be lipid sensors that participate in the regulation of energy homeostasis. Compared with the α and γ peroxisome proliferator-activated receptor isotypes, peroxisome proliferator-activated receptor β functions have long remained an enigma. In this review, we focus on emerging knowledge about peroxisome proliferator-activated receptor β activation and roles. Recent findings We review recent data that suggest key roles in basic cell functions, such as proliferation, differentiation and survival, and in embryonic development and lipid metabolism in peripheral tissues. Summary The newly unveiled roles of peroxisome proliferator-activated receptor β in important basic cell functions certainly justify a further exploration of its potential as a therapeutic target in pathologies such as metabolic syndrome X or skin diseases.