title: Regulator of calcineurin 1 (Rcan1) has a protective role in brain ischemia/reperfusion injury.
abstract: BACKGROUND
  An increase in intracellular calcium concentration [Ca2+]i is one of the first events to take place after brain ischemia. A key [Ca2+]i-regulated signaling molecule is the phosphatase calcineurin (CN), which plays important roles in the modulation of inflammatory cascades. Here, we have analyzed the role of endogenous regulator of CN 1 (Rcan1) in response to experimental ischemic stroke induced by middle cerebral artery occlusion.
  
  
  METHODS
  Animals were subjected to focal cerebral ischemia with reperfusion. To assess the role of Rcan1 after stroke, we measured infarct volume after 48 h of reperfusion in Rcan1 knockout (KO) and wild-type (WT) mice. In vitro studies were performed in astrocyte-enriched cortical primary cultures subjected to 3% oxygen (hypoxia) and glucose deprivation (HGD). Adenoviral vectors were used to analyze the effect of overexpression of Rcan1-4 protein. Protein expression was examined by immunohistochemistry and immunoblotting and expression of mRNA by quantitative real-time Reverse-Transcription Polymerase Chain Reaction (real time qRT-PCR).
  
  
  RESULTS
  Brain ischemia/reperfusion (I/R) injury in vivo increased mRNA and protein expression of the calcium-inducible Rcan1 isoform (Rcan1-4). I/R-inducible expression of Rcan1 protein occurred mainly in astroglial cells, and in an in vitro model of ischemia, HGD treatment of primary murine astrocyte cultures induced Rcan1-4 mRNA and protein expression. Exogenous Rcan1-4 overexpression inhibited production of the inflammatory marker cyclo-oxygenase 2. Mice lacking Rcan1 had higher expression of inflammation associated genes, resulting in larger infarct volumes.
  
  
  CONCLUSIONS
  Our results support a protective role for Rcan1 during the inflammatory response to stroke, and underline the importance of the glial compartment in the inflammatory reaction that takes place after ischemia. Improved understanding of non-neuronal mechanisms in ischemic injury promises novel approaches to the treatment of acute ischemic stroke.
authors.affiliation: Unidad de Investigación Neurovascular, Departamento de Farmacología, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Sobrado
authors.forename: Belén G
authors.initials: BG
authors.lastname: Ramirez
authors.forename: Fernando
authors.initials: F
authors.lastname: Neria
authors.forename: Ignacio
authors.initials: I
authors.lastname: Lizasoain
authors.forename: Maria Lourdes
authors.initials: ML
authors.lastname: Arbones
authors.forename: Takashi
authors.initials: T
authors.lastname: Minami
authors.forename: Juan Miguel
authors.initials: JM
authors.lastname: Redondo
authors.forename: María Angeles
authors.initials: MA
authors.lastname: Moro
authors.forename: Eva
authors.initials: E
authors.lastname: Cano
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000473:pathology; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D020520:Brain Infarction / Q000209:etiology / Q000473:pathology; D002135:Calcium-Binding Proteins; D015687:Cell Hypoxia / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005947:Glucose / Q000172:deficiency; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009124:Muscle Proteins / Q000172:deficiency; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D015427:Reperfusion Injury / Q000378:metabolism*; D014162:Transfection
chemical_list: D002135:Calcium-Binding Proteins; D016207:Cytokines; C511512:DSCR1 protein, mouse; D005904:Glial Fibrillary Acidic Protein; D047908:Intracellular Signaling Peptides and Proteins; D009124:Muscle Proteins; C548050:RCAN1 protein, rat; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; C120817:calcineurin phosphatase; D010744:Phosphoric Monoester Hydrolases; D005947:Glucose