Granulocyte colony-stimulating factor protects the brain against experimental stroke via inhibition of apoptosis and inflammation

Abstract

Objectives: The molecular mechanisms of the anti-apoptotic and anti-inflammatory properties of granulocyte-colony stimulating factor (G-CSF) following focal cerebral ischemia in rats were examined in this study. Methods: Sprague-Dawley rats were randomly divided into three groups: sham, middle cerebral artery occlusion (MCAO) non-treatment and MCAO with G-CSF treatment. Focal ischemia was induced with the suture occlusion method for 90 minutes, and treatment was given at the onset of reperfusion. All animals were killed 24 hours after reperfusion. Assessment included neurological scores, infarction volumes, histology, immunofluorescent staining and Western blotting. Results: G-CSF significantly reduced the infarct volume and ameliorated the early neurological outcome scores. Western blot analysis showed that G-CSF treatment significantly elevated the clAP2 levels and decreased the activation of caspase 3 in the ischemic cortex compared with the non-treated rats. Immunofluorescent works also showed that G-CSF treatment inhibited both neuronal and glial tumor necrosis factor aα and interleukin 1β expressions. Discussion: The neuronal anti-apoptotic action of G-CSF may be mediated in part by the antiapoptotic protein clAP2. G-CSF also exerts anti-inflammatory actions after focal cerebral ischemia by preventing both neuronal and glial pro-inflammatory cytokine expressions. © 2009 W. S. Maney & Son Ltd.