Inhibiting P2Y12 receptor relieves LPS‐induced inflammation and endothelial dysfunction

BACKGROUND: Acute lung injury (ALI) is characterized by abnormal inflammatory response without effective therapies. P2Y12 receptor (P2Y12R) plays a vital role in inflammatory response. This study intends to explore whether P2Y12R antagonists can inhibit LPS-induced inflammatory injury of human pulmonary microvascular endothelial cells (HPMVECs) and endothelial cell dysfunction. METHODS: Using a cell model of ALI, the role of P2Y12R was investigated in LPS-induced HPMVECs. The expression of P2Y12R was detected by RT-qPCR and Western blot analysis assay and TNF-α, IL-1β, and IL-6 levels were analyzed by RT-qPCR. NO levels were also analyzed through NO kit. The levels of NF-κB p65, P-IκB-α, and IκB-α, as well as p-AKT and eNOS levels were detected by Western blot analysis assay. Wound healing assay was performed to evaluate HPMVECs migration. FITC-dextran was used to evaluate endothelial cell permeability, and the analysis of adherens junction protein VE-cadherin and endothelial cell tight junction proteins ZO-1, Claudin 5 and Occludin expression was performed by RT-qPCR and Western blot analysis assay. RESULTS: In vitro, LPS increased the expression levels of P2Y12R and pro-inflammatory mediators (TNF-α, IL-1β, and IL-6), followed by a decrease in HPMVECs migration. In addition, LPS led to an increase in endothelial cell permeability. P2Y12R antagonists Ticagrelor or clopidogrel treatment significantly reversed these effects of LPS. CONCLUSION: The inhibitor of P2Y12R was able to decrease inflammatory response, promote migration and improve endothelial cell function and permeability, suggesting a key role of P2Y12R in ALI.