caa a22 4500 606176152 CHVBK 20210128100746.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00018-015-1973-4 doi (NATIONALLICENCE)springer-10.1007/s00018-015-1973-4 Rab5-mediated VE-cadherin internalization regulates the barrier function of the lung microvascular endothelium [Elektronische Daten] [Junjun Yang, Wei Yao, Guisheng Qian, Zhenghua Wei, Guangyu Wu, Guansong Wang] The small GTPase Rab5 has been well defined to control the vesicle-mediated plasma membrane protein transport to the endosomal compartment. However, its function in the internalization of vascular endothelial (VE)-cadherin, an important component of adherens junctions, and as a result regulating the endothelial cell polarity and barrier function remain unknown. Here, we demonstrated that lipopolysaccharide (LPS) simulation markedly enhanced the activation and expression of Rab5 in human pulmonary microvascular endothelial cells (HPMECs), which is accompanied by VE-cadherin internalization. In parallel, LPS challenge also induced abnormal cell polarity and dysfunction of the endothelial barrier in HPMECs. LPS stimulation promoted the translocation of VE-cadherin from the plasma membrane to intracellular compartments, and intracellularly expressed VE-cadherin was extensively colocalized with Rab5. Small interfering RNA (siRNA)-mediated depletion of Rab5a expression attenuated the disruption of LPS-induced internalization of VE-cadherin and the disorder of cell polarity. Furthermore, knockdown of Rab5 inhibited the vascular endothelial hyperpermeability and protected endothelial barrier function from LPS injury, both in vitro and in vivo. These results suggest that Rab5 is a critical mediator of LPS-induced endothelial barrier dysfunction, which is likely mediated through regulating VE-cadherin internalization. These findings provide evidence, implicating that Rab5a is a potential therapeutic target for preventing endothelial barrier disruption and vascular inflammation. Springer Basel, 2015 Rab5 GTPase nationallicence VE-cadherin nationallicence Actin cytoskeleton nationallicence Internalization nationallicence Endothelium nationallicence Barrier function nationallicence Acute lung injury nationallicence Endosome nationallicence Adherens junction nationallicence Cell polarity nationallicence HPMECs : Human pulmonary microvascular endothelial cells nationallicence LPS : Lipopolysaccharide nationallicence VE-cadherin : Vascular endothelial-cadherin nationallicence Rab5a WT : Wild-type Rab5a nationallicence siRNA : Small interference RNA nationallicence ALI : Acute lung injury nationallicence ARDS : Acute respiratory distress syndrome nationallicence BSA : Bovine serum albumin nationallicence CI : Cell index nationallicence VEGF : Vascular endothelial growth factor nationallicence JAM-A : Junction adhesion molecule A nationallicence PAR3 : Partitioning defective 3 nationallicence PAR6 : Partitioning defective 6 nationallicence aPKC : Atypical protein kinase C nationallicence PCP : Planar cell polarity nationallicence Podxl : Podocalyxin nationallicence F-actin : Filamentous actin nationallicence EBA : Evans blue albumin nationallicence WB : Western blot nationallicence i.p. : Intraperitoneal nationallicence Yang Junjun Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut Yao Wei Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut Qian Guisheng Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut Wei Zhenghua Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut Wu Guangyu Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., 30912, Augusta, GA, USA aut Wang Guansong Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut Cellular and Molecular Life Sciences Springer International Publishing 72/24(2015-12-01), 4849-4866 1420-682X 72:24<4849 2015 72 18 https://doi.org/10.1007/s00018-015-1973-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00018-015-1973-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yang Junjun Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut NATIONALLICENCE 700 1- Yao Wei Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut NATIONALLICENCE 700 1- Qian Guisheng Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut NATIONALLICENCE 700 1- Wei Zhenghua Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut NATIONALLICENCE 700 1- Wu Guangyu Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., 30912, Augusta, GA, USA aut NATIONALLICENCE 700 1- Wang Guansong Institute of Respiratory Diseases and Critical Care, Xinqiao Hospital, Third Military Medical University, 400037, Chongqing, China aut NATIONALLICENCE 773 0- Cellular and Molecular Life Sciences Springer International Publishing 72/24(2015-12-01), 4849-4866 1420-682X 72:24<4849 2015 72 18