Low Doses of G-CSF Prevent Cerebral Infarction and Maintain Muscle Strength in an Experimental Model of Global Ischemic Stroke

Background: Stroke is a major cause of severe and long-term disability in adult individuals. Treatment of this disease is limited by the narrow therapeutic window in which intervention is crucial. An alternative therapy for stroke could be cellular growth factors, which participate in several pathways that mediate neuronal cell death. Methods: We evaluated the neuroprotective ability of different doses of granulocyte colonystimulating factor (G-CSF; 5, 50 and 100 μg/kg/day) in the mouse model of global cerebral ischemia induced by bilateral occlusion of the common carotid arteries for 80 minutes. The control group received vehicle (5% glucose solution) and the treated group was administered with G-CSF at two postsurgery time-points: immediately after and 24 hours after. Subsequently, muscle strength, leukocyte count, infarcted cortical area, and apoptosis/TUNEL were evaluated. Results: The global ischemia promoted an impairment of the strength (16%) and a cerebral infarction (0.437±0.08 cm2) which were accompanied by apoptosis evaluated by TUNEL in control mice. In mice treated with G-CSF the strength function was maintained, the infarcted area (~70%) and apoptosis were decreased in a similar magnitude in all treated groups. Accordingly, the cytokine activities were confirmed by blood leukocyte count that was increased approximately 2-fold than that observed in the control group. Conclusion: The results indicate a neuroprotective effect of G-CSF, even in small doses, in mice subjected to global cerebral ischemia, thereby reducing the neurofunctional impairment caused by stroke, when considering the maintenance of muscle strength in the treated animals.