| Stroke is a common disease, and also a leading cause of death and disability worldwide. Effective therapeutics for the rehabilitation of stroke survivors have yet to be developed. In recent years, neural stem cell transplantation ameliorate stroke deficits in experimental animal models, however, it also poses enormous practical and ethical difficulties. In light of the experiences of widely and safely usage of rhG-CSF in peripheral blood stem cell transplantation(PBSCT) for the treatment of hematological diseases and immune disorders, the capability of MSCs to pass through the blood-brain barrier and differentiate into astrocytes and neurons after intravenous infusion, the protective effects of rhG-CSF in splanchnic and cardiac ischemia, and the neuroprotection of other hematopoietic factors such as G-CSF and EPO, we hypothesize that subcutaneous administration of rhG-CSF reduce functional deficits after stroke in rats. To provide proofs for the possibility of rhG-CSF treatment in ischemic stroke, we examined the effects of rhG-CSF on the functional outcome, cell proliferation, neovascularization and expression of proteins associated with neural plasticity after reperfusion of focal ischemia in rat brain.Part I The effect of rhG-CSF on the outcome of cerebral ischemia in ratsFlow cytometry was performed to test the changes in percentage of CD34+ cells in peripheral blood before and after rhG-CSF mobilization. The number of CD34+ cells mobilized to peripheral blood peaked at day 2 and day 7 of rhG-CSF administration. To test the neuroprotection of rhG-CSF, rats (n=72) were subjected to 2 hours of middle cerebral artery occlusion(MCAO). Testgroups consisted of MCAO alone (groupl, 2,3; n=12 each) and subcutaneous injection of 20ug/kg/d rhG-CSF for 5 days began at 24 hours after MCAO(group4, 5, 6; n=12 each). The rats were euthanized at 7 days (groups 1 and 4), 14 days (groups 2 and 5) and 21 days (groups 3 and 6) after MCAO respectively. Mortality, peripheral WBC count, body weight, behavior tests and infarct area were performed after MCAO. Low mortality, normal body weight, and significant recovery of neurological deficiency were found in animals treated with rhG-CSF compared with control animals. But rhG-CSF had no effects on peripheral WBC count and infarct area.Part II The effect of rhG-CSF on the cell proliferation and neovascularization after cerebral ischemia in ratsRats were subjected to 2 hours of MCAO. Immunohistochemical techniques were used to detect the expression of 5-bromodeoxyuridine(BrdtI, for proliferated cells), neuroepithelial stem protein(nestin, for immature cells), factor Vffl(for neovascularization), microtubule associated protein~2(MAP-2, for neurons) and glial fibrilary acidic protein(GFAP, for astrocytes) in the infarct and peri-infarct area of the brain. More BrdU, nestin, factor Vi, MAP-2 positive cells and less GFAP immunoreactivity were found in rhG-CSF-treated animals compared with control animals, suggesting rhG-CSF promoted brain cell proliferation and neovascularization, prevented neural death and held back gliosis after ischemia/reperfusion lesion.Part in The effect of rhG-CSF on the expression of proteins associated with neuronal plasticity after cerebral ischemia in ratsRats were subjected to 2 hours of middle cerebral artery occlusion (MCAO). The mRNA and protein expression of MAP-2 and SYN were assessed by RT-PCR and immunohistochemical techniques respectively. Compared with control animals, the mRNA and protein expression of MAP-2 and SYN was significantly upregulated in animals treated with rhG-CSF, showing that rhG-CSF enhancedthe expression of proteins associated with neuronal plasticity after ischemia/reperfusion lesion.Conclusions1. rhG-CSF treatment reduced mortality after ischemia/reperfusion lesion.2. rhG-CSF treatment enhances functional recovery after experimental ischemia/reperfusion lesion.3. rhG-CSF promoted brain cell proliferation after ischemia/reperfusion lesion.4. rhG-CSF treatment prevented neural death after i... |
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