Enhancing Mitophagy with PEP-1-CAT Attenuates Vascular Inflammation and Atherogenesis in Mice.

Abstract

The gradual decline of endothelial function and the intensification of inflammatory responses form the basis for the occurrence and development of age-related diseases such as atherosclerosis (AS). Mitochondrial dysfunction-manifested by excessive reactive oxygen species (ROS) production, reduced mitochondrial membrane potential, and impaired mitophagic flux-and sterile inflammation are hallmarks of aged vasculature. We investigated whether bolstering mitochondrial quality control via the novel cell-penetrating antioxidant PEP-1-Catalase (CAT) could mitigate these key features of vascular aging. To model age-associated vascular pathology, ApoE⁻/⁻ mice were fed a high-fat diet (HFD) and treated with PEP-1-CAT. Endothelial cell function, plaque burden, and inflammation were analyzed. In vitro, human endothelial cells (HUVECs) were subjected to inflammatory stress and treated with PEP-1-CAT, with or without modulators of mitophagy. We assessed mitochondrial ROS, membrane potential, NOD-like receptor protein 3 (NLRP3) inflammasome activation, and the PINK1-Parkin pathway. PEP-1-CAT treatment significantly ameliorated atherogenesis and improved features of plaque stability in mice. It suppressed vascular oxidative stress, restored mitochondrial membrane potential, enhanced mitophagic flux, and inhibited NLRP3-driven inflammation. In endothelial cells, PEP-1-CAT attenuated mitochondrial oxidative stress and dysfunction. Crucially, it activated the PINK1-Parkin pathway to promote mitophagy, which was essential for its anti-inflammatory effects, as mitophagy inhibition abrogated the suppression of the NLRP3 inflammasome. Our findings demonstrate that targeting mitochondrial health with PEP-1-CAT alleviates hallmarks of atherosclerotic vascular pathology, including endothelial dysfunction and inflammation, by enhancing mitophagy. This strategy of restoring mitochondrial quality control presents a promising therapeutic approach to delay atherosclerotic vascular pathology.