title: Heat stress-induced disruption of endothelial barrier function is via PAR1 signaling and suppressed by Xuebijing injection.
abstract: Increased vascular permeability leading to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is central to the pathogenesis of heatstroke. Protease-activated receptor 1 (PAR1), the receptor for thrombin, plays a key role in disruption of endothelial barrier function in response to extracellular stimuli. However, the role of PAR1 in heat stress-induced endothelial hyper-permeability is unknown. In this study, we measured PAR1 protein expression in heat-stressed human umbilical venous endothelial cells (HUVECs), investigated the influences of PAR1 on endothelial permeability, F-actin rearrangement, and moesin phosphorylation by inhibiting PAR1 with its siRNA, neutralizing antibody (anti-PAR1), specific inhibitor(RWJ56110), and Xuebijing injection (XBJ), a traditional Chinese medicine used for sepsis treatment, and evaluated the role of PAR1 in heatstroke-related ALI/ARDS in mice by suppressing PAR1 with RWJ56110, anti-PAR1and XBJ. We found that heat stress induced PAR1 protein expression 2h after heat stress in endothelial cells, caused the release of endothelial matrix metalloprotease 1, an activator of PAR1, after 60 or 120 min of heat stimulation, as well as promoted endothelial hyper-permeability and F-actin rearrangement, which were inhibited by suppressing PAR1 with RWJ56110, anti-PAR1 and siRNA. PAR1 mediated moesin phosphorylation, which caused F-actin rearrangement and disruption of endothelial barrier function. To corroborate findings from in vitro experiments, we found that RWJ56110 and the anti-PAR1 significantly decreased lung edema, pulmonary microvascular permeability, protein exudation, and leukocytes infiltrations in heatstroke mice. Additionally, XBJ was found to suppress PAR1-moesin signal pathway and confer protective effects on maintaining endothelial barrier function both in vitro and in vivo heat-stressed model, similar to those observed above with the inhibition of PAR1. These results suggest that PAR1 is a potential therapeutic target in heatstroke.
authors.affiliation: Department of ICU, General Hospital of Guangzhou Military Command, Key Laboratory of Tropical Zone Trauma Care and Tissue Repair of PLA, Guangzhou, China; Postdoctoral Workstation, Huabo Bio-pharmaceutical Research Institute, Guangzhou, China.
authors.forename: Qiulin
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Southern Medical University, Guangzhou, China.
authors.forename: Jingxian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Zhenglian
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Pathophysiology, Southern Medical University, Guangzhou, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Guo
authors.affiliation: Guangzhou University of Chinese Medicine, Guangzhou, China.
authors.forename: Gengbiao
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Southern Medical University, Guangzhou, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pathophysiology, Southern Medical University, Guangzhou, China.
authors.forename: Qiaobing
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Department of ICU, General Hospital of Guangzhou Military Command, Key Laboratory of Tropical Zone Trauma Care and Tissue Repair of PLA, Guangzhou, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Su
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D055371:Acute Lung Injury / Q000188:drug therapy / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D018893:Bronchoalveolar Lavage; D002199:Capillary Permeability / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000494:pharmacology* / Q000627:therapeutic use*; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism*; D006358:Hot Temperature; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D034741:RNA, Small Interfering; D044463:Receptor, PAR-1 / Q000378:metabolism*; D012128:Respiratory Distress Syndrome / Q000188:drug therapy / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D004365:Drugs, Chinese Herbal; D034741:RNA, Small Interfering; D044463:Receptor, PAR-1; C549376:Xuebijing