title: Impact of the neutrophil response to granulocyte colony-stimulating factor on the risk of hemorrhage when used in combination with tissue plasminogen activator during the acute phase of experimental stroke.
abstract: BACKGROUND
  Granulocyte colony-stimulating factor (G-CSF) is a pharmacologic agent inducing neutrophil mobilization and a new candidate for neuroprotection and neuroregeneration in stroke. Its effects when used in combination with tissue plasminogen activator (tPA) were explored during the acute phase of ischemic stroke.
  
  
  METHODS
  We used a middle cerebral artery occlusion (MCAO) model of cerebral ischemia, associated with treatment with tPA, in male spontaneously hypertensive rats (SHR). Granulocyte colony-stimulating factor (G-CSF; 60 μg/kg) was injected just before tPA. Neutrophil response in peripheral blood and in the infarct area was quantified in parallel to the infarct volume. Protease matrix metallopeptidase 9 (MMP-9) release from circulating neutrophils was analyzed by immunochemistry and zymography. Vascular reactivity and hemorrhagic volume in the infarct area was also assessed.
  
  
  RESULTS
  Twenty four hours after ischemia and tPA, G-CSF administration induced a significant increase of neutrophils in peripheral blood (P <0.05). At 72 hours post-ischemia, G-CSF was significantly associated with an increased risk of hemorrhage in the infarct area (2.5 times more likely; P <0.05) and significant cerebral endothelium-dependent dysfunction. Ex vivo, an increased MMP-9 release from neutrophils after tPA administration correlated to the increased hemorrhagic risk (P <0.05). In parallel, G-CSF administration was associated with a decreased neutrophil infiltration in the infarct area (-50%; P <0.05), with a concomitant significant neuroprotective effect (infarct volume: -40%; P <0.05).
  
  
  CONCLUSIONS
  We demonstrate that G-CSF potentiates the risk of hemorrhage in experimental stroke when used in combination with tPA by inducing neutrophilia. This effect is concomitant to an increased MMP-9 release from peripheral neutrophils induced by the tPA treatment. These results highlight the potential hemorrhagic risk of associating G-CSF to thrombolysis during the acute phase of stroke.
authors.affiliation: EA 1046 - Département de Pharmacologie médicale, Université de Lille 2 - Faculté de Médecine, 1 place de Verdun, Lille cedex F-59037, France. sophie.gautier@chru-lille.fr.
authors.forename: Sophie
authors.initials: S
authors.lastname: Gautier
authors.forename: Thavarak
authors.initials: T
authors.lastname: Ouk
authors.forename: Madjid
authors.initials: M
authors.lastname: Tagzirt
authors.forename: Catherine
authors.initials: C
authors.lastname: Lefebvre
authors.forename: Maud
authors.initials: M
authors.lastname: Laprais
authors.forename: Olivier
authors.initials: O
authors.lastname: Pétrault
authors.forename: Annabelle
authors.initials: A
authors.lastname: Dupont
authors.forename: Didier
authors.initials: D
authors.lastname: Leys
authors.forename: Régis
authors.initials: R
authors.lastname: Bordet
mesh_terms: D000818:Animals; D020520:Brain Infarction / Q000209:etiology; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D004727:Endothelium / Q000187:drug effects; D005343:Fibrinolytic Agents / Q000009:adverse effects*; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage*; D006470:Hemorrhage / Q000139:chemically induced*; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020556:Neutrophil Infiltration / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D015427:Reperfusion Injury / Q000188:drug therapy / Q000209:etiology; D018709:Statistics, Nonparametric; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000009:adverse effects*
chemical_list: D005343:Fibrinolytic Agents; D016179:Granulocyte Colony-Stimulating Factor; D009195:Peroxidase; D010959:Tissue Plasminogen Activator; D020780:Matrix Metalloproteinase 9