Molecular mechanisms of mitochondrial uncoupling: focus on 2,4-dinitrophenol.

2,4-Dinitrophenol (DNP) is an artificial mitochondrial uncoupler that was used as an anti-obesity treatment until it was withdrawn due to high toxicity, a narrow therapeutic window, and a lack of an antidote. Despite these concerns, DNP’s efficacy surpasses that of many contemporary anti-obesity drugs, sparking renewed interest in its potential use under controlled conditions. However, the development of antidotes for their toxicity and advancement as therapeutic agents has been impeded by a critical gap in our understanding of the precise molecular mechanisms by which DNP and similar uncouplers operate within mitochondria. This review provides a brief historical overview of DNP use and explores various proposed molecular mechanisms of DNP action. It also summarizes recent results obtained using conductance measurements of artificial bilayer membranes, patch clamp of mitoplasts, in silico analysis, and cryo-electron microscopy. Continued integration of the electrophysiological, structural, and computational approaches is expected to clarify the molecular basis of DNP-mediated uncoupling, enabling the rational development of safer uncouplers and mechanism-based antidotes.