Loss of LRRK2 Protects Against Ox-LDL-Induced Endothelial Oxidative Damage Via NRF2

This study investigated the role of LRRK2, a protein implicated in cancers but poorly understood in atherosclerosis, in oxidized low-density lipoprotein (Ox-LDL)-induced endothelial dysfunction. An in vitro model was established using HUVECs treated with Ox-LDL. Cell viability, apoptosis, reactive oxygen species (ROS) levels, and mitochondrial membrane potential were assessed using standard assays. Results showed that Ox-LDL exposure caused dose- and time-dependent decreases in cell viability and concurrent upregulation of LRRK2 expression. Silencing LRRK2 significantly improved cell survival and suppressed Ox-LDL-induced apoptosis, as evidenced by modulation of key apoptotic proteins (decreased cleaved-caspase-3, cleaved-caspase-9, and Bax; increased Bcl-2). LRRK2 silencing alleviated oxidative stress by elevating antioxidant superoxide dismutase and glutathione levels, reducing malondialdehyde and ROS production, and restoring mitochondrial membrane potential. Mechanistically, si-LRRK2 enhanced NRF2 expression and nuclear translocation, leading to increased levels of its downstream targets heme oxygenase-1 and NAD(P)H quinone dehydrogenase 1. The critical role of this pathway was confirmed, as pharmacological inhibition of NRF2 with ML385 reversed all protective effects of si-LRRK2. LRRK2 is a key mediator of Ox-LDL-induced endothelial damage. Its inhibition protects HUVECs by activating the NRF2 signaling pathway, suggesting LRRK2 as a promising novel therapeutic target for combating endothelial dysfunction in atherosclerosis and related cardiovascular diseases.