title: The extracellular matrix protein laminin-10 promotes blood-brain barrier repair after hypoxia and inflammation in vitro.
abstract: BACKGROUND
  The blood-brain barrier (BBB) of the central nervous system (CNS) is essential for normal brain function. However, the loss of BBB integrity that occurs after ischaemic injury is associated with extracellular matrix (ECM) remodelling and inflammation, and contributes to poor outcome. ECM remodelling also contributes to BBB repair after injury, but the precise mechanisms and contribution of specific ECM molecules involved are unknown. Here, we investigated the mechanisms by which hypoxia and inflammation trigger loss of BBB integrity and tested the hypothesis ECM changes could contribute to BBB repair in vitro.
  
  
  METHODS
  We used an in vitro model of the BBB, composed of primary rat brain endothelial cells grown on collagen (Col) I-, Col IV-, fibronectin (FN)-, laminin (LM) 8-, or LM10-coated tissue culture plates, either as a single monolayer culture or on Transwell® inserts above mixed glial cell cultures. Cultures were exposed to oxygen-glucose deprivation (OGD) and/or reoxygenation, in the absence or the presence of recombinant interleukin-1β (IL-1β). Cell adhesion to ECM molecules was assessed by cell attachment and cell spreading assays. BBB dysfunction was assessed by immunocytochemistry for tight junction proteins occludin and zona occludens-1 (ZO-1) and measurement of trans-endothelial electrical resistance (TEER). Change in endothelial expression of ECM molecules was assessed by semi-quantitative RT-PCR.
  
  
  RESULTS
  OGD and/or IL-1 induce dramatic changes associated with loss of BBB integrity, including cytoplasmic relocalisation of membrane-associated tight junction proteins occludin and ZO-1, cell swelling, and decreased TEER. OGD and IL-1 also induced gene expression of key ECM molecules associated with the BBB, including FN, Col IV, LM 8, and LM10. Importantly, we found that LM10, but not FN, Col IV, nor LM8, plays a key role in maintenance of BBB integrity and reversed most of the key hallmarks of BBB dysfunction induced by IL-1.
  
  
  CONCLUSIONS
  Our data unravel new mechanisms of BBB dysfunction induced by hypoxia and inflammation and identify LM10 as a key ECM molecule involved in BBB repair after hypoxic injury and inflammation.
authors.affiliation: Manchester Pharmacy School, University of Manchester, Manchester, M13 9PT, UK. kasabay@hotmail.com.
authors.forename: Korakoch
authors.initials: K
authors.lastname: Kangwantas
authors.affiliation: Faculty of Life Sciences, University of Manchester, A.V. Hill Building, Oxford Road, Manchester, M13 9PT, UK. emmanuel.pinteaux@manchester.ac.uk.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Pinteaux
authors.affiliation: Manchester Pharmacy School, University of Manchester, Manchester, M13 9PT, UK. Jeff.Penny@manchester.ac.uk.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Penny
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D001921:Brain / Q000166:cytology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D018920:Coculture Techniques; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000172:deficiency; D000860:Hypoxia; D053583:Interleukin-1beta / Q000494:pharmacology; D007797:Laminin / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D062793:Occludin / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D053583:Interleukin-1beta; D007797:Laminin; D062793:Occludin; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; C119013:laminin 10; D005947:Glucose
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