Prophylactic supplementation of 20-HETE ameliorates hypoxia/reoxygenation injury in pulmonary vascular endothelial cells by inhibiting apoptosis

Abstract Hypoxia reoxygenation (HR) injury perturbs structural and functional syncytium in lung tissues. It is commonly implicated in conditions such as stroke, lung transplant or severe pneumonia. In the present study, we investigated the cytoprotective action of 20-hydroxyeicosatetraenoic acid (20-HETE) on pulmonary vascular endothelial cells (PMVECs) under normoxic and hypoxic niche followed by HR. 20-HETE pretreatment showed a protective effect at a concentration of 1μM as there was a marked increase (20%) in the cell viability compared to control and HR groups. Pretreatment of 20-HETE in HR induced injury decreased ROS production dictated its antioxidant property. Similarly, SOD and ATP levels were also downregulated by 20-HETE pretreatment. Cell apoptosis was detected by TUNEL assay, Acridine orange, and procaspase-3 cleavage, caspase-3 activity assay, respectively. JC-1 mitochondrial membrane potential assay and protein expression pattern of BCL-2, and BAD phosphorylation status were examined. The results showed that HR induced significant increase of apoptotic PMVECs, while 20-HETE pretreatment attenuated the effects. Further, 20-HETE pretreatment activated PI3K/Akt and HIF-1α signaling pathway to exhibit its protective effects against HR-induced oxidative stress and apoptosis. Overall, the results concluded the potent antioxidant role of 20-HETE in aiding cytoprotection upon HR injury.