title: Activation of brain endothelial cells by interleukin-1 is regulated by the extracellular matrix after acute brain injury.
abstract: The extracellular matrix (ECM) of the central nervous system (CNS) is essential for normal brain function, whilst ECM remodelling is associated with cerebrovascular inflammation driven by the cytokine interleukin-1 (IL-1) after acute brain injury. The effect of ECM remodelling on endothelial activation during neuroinflammation remains unknown. Here we report that ECM remodelling in the cerebrovasculature critically regulates IL-1-induced endothelial cell activation after cerebral ischaemia; Expression levels of ECM molecules associated with the cerebrovasculature, namely fibronectin (FN) and collagen IV (Col IV), strongly increased in brain blood vessels after middle cerebral artery occlusion (MCAo) in a time-dependent manner, reaching a peak of vascular expression 48 h after MCAo. In cultures, FN and Col IV (but also laminin-1 and fibrillin-1) promoted strong attachment of the GPNT endothelial cell line and primary rat brain endothelial cells, which was markedly inhibited by RGD (Arg-Gly-Asp) peptide, or specific integrin β1, α4, α5 and αv blockade. IL-1β-induced activation of extracellular-regulated kinase 1/2 (ERK1/2) and nuclear factor κB (NFκB), and synthesis of cytokine-induced neutrophil chemoattractant (CINC-1) were enhanced in cells plated onto ECM molecules, and these responses were inhibited by selective integrin blockade. Finally, increased ECM expression in vessels after MCAo was found associated with vinculin clustering, increased integrin β1 expression, and increased IL-1 receptor associated kinase-1 (IRAK-1) activity in endothelial cells and perivascular astrocytes. Therefore, our data indicate a novel function for the ECM in the regulation of cerebrovascular inflammation triggered by IL-1 during acute brain injury.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK.
authors.forename: Lauren
authors.initials: L
authors.lastname: Summers
authors.forename: Korakoch
authors.initials: K
authors.lastname: Kangwantas
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rodriguez-Grande
authors.forename: Adam
authors.initials: A
authors.lastname: Denes
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Penny
authors.forename: Cay
authors.initials: C
authors.lastname: Kielty
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Pinteaux
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002460:Cell Line; D002478:Cells, Cultured; D054360:Chemokine CXCL1 / Q000235:genetics / Q000378:metabolism; D003094:Collagen / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism* / Q000473:pathology; D016023:Integrins / Q000235:genetics / Q000378:metabolism; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism*; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D008810:Mice, Inbred C57BL; D051381:Rats; D017208:Rats, Wistar
chemical_list: D054360:Chemokine CXCL1; D005353:Fibronectins; D016023:Integrins; D007375:Interleukin-1; D003094:Collagen; D053592:Interleukin-1 Receptor-Associated Kinases
keywords: Brain injury; CINC-1; Cerebrovasculature; ECM; ERK1/2; Endothelia; Extracellular matrix; GFAP; IL-1; IRAK-1; Inflammation; Integrin; Interleukin; MCAo; NFκB; cytokine-induced neutrophil chemoattractant; extracellular matrix; extracellular-regulated kinase 1/2; glial fibrillary acidic protein; interleukin-1; interleukin-1 receptor associated kinase-1; middle cerebral artery occlusion; nuclear factor κB