title: Decrease of intracellular chloride concentration promotes endothelial cell inflammation by activating nuclear factor-κB pathway.
abstract: Recent evidence suggested that ClC-3 channel/antiporter is involved in regulation of nuclear factor (NF)-κB activation. However, the mechanism explaining how ClC-3 modulates NF-κB signaling is not well understood. We hypothesized that ClC-3-dependent alteration of intracellular chloride concentration ([Cl(-)](i)) underlies the effect of ClC-3 on NF-κB activity in endothelial cells. Here, we found that reduction of [Cl(-)](i) increased tumor necrosis factor-α (TNFα)-induced expression of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 and adhesion of monocytes to endothelial cells (P<0.05; n=6). In Cl(-) reduced solutions, TNFα-evoked IκB kinase complex β and inhibitors of κBα phosphorylation, inhibitors of κBα degradation, and NF-κB nuclear translocation were enhanced. In addition, TNFα and interleukin 1β could activate an outward rectifying Cl(-) current in human umbilical vein endothelial cells and mouse aortic endothelial cells. Knockdown or genetic deletion of ClC-3 inhibited or abolished this Cl(-) conductance. Moreover, Cl(-) channel blockers, ClC-3 knockdown or knockout remarkably reduced TNFα-induced intercellular adhesion molecule 1 and vascular cell adhesion molecule 1expression, monocytes to endothelial cell adhesion, and NF-κB activation (P<0.01; n=6). Furthermore, TNFα-induced vascular inflammation and neutrophil infiltration into the lung and liver were obviously attenuated in ClC-3 knockout mice (P<0.01; n=7). Our results demonstrated that decrease of [Cl(-)](i) induced by ClC-3-dependent Cl(-) efflux promotes NF-κB activation and thus potentiates TNFα-induced vascular inflammation, suggesting that inhibition of ClC-3-dependent Cl(-) current or modification of intracellular Cl(-) content may be a novel therapeutic approach for inflammatory diseases.
authors.affiliation: Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2 Rd, Guangzhou 510080, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
authors.forename: Lin-Yan
authors.initials: LY
authors.lastname: Huang
authors.forename: De-Yi
authors.initials: DY
authors.lastname: Zeng
authors.forename: Er-Wen
authors.initials: EW
authors.lastname: Huang
authors.forename: Si-Jia
authors.initials: SJ
authors.lastname: Liang
authors.forename: Yong-Bo
authors.initials: YB
authors.lastname: Tang
authors.forename: Ying-Xue
authors.initials: YX
authors.lastname: Su
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.forename: Fei
authors.initials: F
authors.lastname: Shang
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Wu
authors.forename: Li-Xiong
authors.initials: LX
authors.lastname: Xiong
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Lv
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Yong-Yuan
authors.initials: YY
authors.lastname: Guan
authors.forename: Jia-Guo
authors.initials: JG
authors.lastname: Zhou
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D018118:Chloride Channels / Q000235:genetics / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005260:Female; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D053583:Interleukin-1beta / Q000494:pharmacology; D042541:Intracellular Space / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D020556:Neutrophil Infiltration / Q000187:drug effects; D034622:RNA Interference; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D018118:Chloride Channels; D002712:Chlorides; C115376:ClC-3 channel; D053583:Interleukin-1beta; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1