title: Disruption of in vitro endothelial barrier integrity by Japanese encephalitis virus-Infected astrocytes.
abstract: Blood-brain barrier (BBB) characteristics are induced and maintained by crosstalk between brain microvascular endothelial cells and neighboring cells. Using in vitro cell models, we previously found that a bystander effect was a cause for Japanese encephalitis-associated endothelial barrier disruption. Brain astrocytes, which neighbor BBB endothelial cells, play roles in the maintenance of BBB integrity. By extending the scope of relevant studies, a potential mechanism has been shown that the activation of neighboring astrocytes could be a cause of disruption of endothelial barrier integrity during the course of Japanese encephalitis viral (JEV) infection. JEV-infected astrocytes were found to release biologically active molecules that activated ubiquitin proteasome, degraded zonula occludens-1 (ZO-1) and claudin-5, and disrupted endothelial barrier integrity in cultured brain microvascular endothelial cells. JEV infection caused astrocytes to release vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and matrix metalloproteinases (MMP-2/MMP-9). Our data demonstrated that VEGF and IL-6 released by JEV-infected astrocytes were critical for the proteasomal degradation of ZO-1 and the accompanying disruption of endothelial barrier integrity through the activation of Janus kinase-2 (Jak2)/signal transducer and activator of transcription-3 (STAT3) signaling as well as the induction of ubiquitin-protein ligase E3 component, n-recognin-1 (Ubr 1) in endothelial cells. MMP-induced endothelial barrier disruption was accompanied by MMP-mediated proteolytic degradation of claudin-5 and ubiquitin proteasome-mediated degradation of ZO-1 via extracellular VEGF release. Collectively, these data suggest that JEV infection could activate astrocytes and cause release of VEGF, IL-6, and MMP-2/MMP-9, thereby contributing, in a concerted action, to the induction of Japanese encephalitis-associated BBB breakdown. GLIA 2015;63:1915-1932.
authors.affiliation: Department of Surgery, Fong-Yuan Hospital, Taichung, Taiwan.
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Division of Urology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Jian-Ri
authors.initials: JR
authors.lastname: Li
authors.affiliation: Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Wen-Ying
authors.initials: WY
authors.lastname: Chen
authors.affiliation: Division of Urology, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Yen-Chuan
authors.initials: YC
authors.lastname: Ou
authors.affiliation: Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.|Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Ching-Yi
authors.initials: CY
authors.lastname: Lai
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.|Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Yu-Hui
authors.initials: YH
authors.lastname: Hu
authors.affiliation: Department of Anesthesiology, Taichung Veterans General Hospital, Taichung, Taiwan.|Department of Financial and Computational Mathematics, Providence University, Taichung, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Wu
authors.affiliation: Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Sciences and Technology, Taichung, Taiwan.
authors.forename: Chen-Jung
authors.initials: CJ
authors.lastname: Chang
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.|Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan.|Center for General Education, Tunghai University, Taichung, Taiwan.|Department of Nursing, HungKuang University, Taichung, Taiwan.
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Chen
keywords: central nervous system; flaviviruses; glia; neurotropism