G-csf Reduces The Expressionlevels Of Inos And Cox2 In Rat Cerebral Hemorrhage

Objective:To investigate the effect of granulocyte colony-stimulating factor(G-CSF)on the expression of inducible nitric oxide synthase(iNOS)and cyclooxygenase-2(COX2)in the brain tissues of cerebral hemorrhage in rats.Methods:Thirty-six healthy male SD rats(8-week-old,body weigh 250?300g)were randomly divided into 7 groups:0 hour(h)group,1h group,6h group,12h group,24h group,3 day(d)group and 7d group.Each group was given 6 rats.The intracerebral hemorrhage model was made by the brain injection of autologous blood(right outer capsule,50ul).On operative times(0h,1h,6h,12h,24h,3d and 7d),the rats were killed by the dislocated cervical vertebra,and then the cerebral hemorrhage was quickly extracted.The brain tissues were kept at-80?.In addition,sixty healthy male SD rats(8 weeks old,weighing 250?300g)underwent cerebral hemorrhage operation were randomly divided into 5 groups:negative control group(saline),positive control group(Hb),G-CSF treatment groups(low dose 25,middle dose 50,high dose 75 g/kg;subcutaneous injection at 2h and 14h after operation).At 24h and 7d after the operation,the rats were killed by dislocated cervical vertebra,and the brain tissues of cerebral hemorrhage were quickly sampled and kept at-70?.Total protein was extracted from the brain tissues using RIPA lysate buffer on ice and were subjected to Western blotting assay for the evaluation of the contents of INOS and COX2 proteins as well as ?-action.Results:In rat cerebral hemorrhage model,the changes in the iNOS protein levels of the hemorrhaged brain tissues increased at 12h and reached a peak at 24h and decreased after the hemorrhagic injury;the COX2 protein levels appeared as early as 6h and reached a peak at 24h and almost disappeared at 3d and 7d after the brain injury.Namely,COX2 protein levels increased rapidly and decreased significantly after the brain injury for 24h:iNOS protein levels significantly increased in the rat hemorrhaged brain tissues at 12h after the injury and still kept high levels at day 7 after the brain injury as compared with the control rats.Although G-CSF treatment with lose-dose did not significantly affect on COX2 and INOS protein expressions in the hemorrhaged brain tissues at 24h after the hemorrhagic injury,middle and high doses of G-CSF significantly suppressed both targeted protein expressions.Similarly,on the operative day 7,both treatments improved iNOS protein levels.However,the levels of COX2 protein was improved in all intervention groups at day 7 after the injury.Conclusion:These finding suggests that G-CSF may improve inflammation-related iNOS and COX2 protein expressions in the peripheral tissue of the cerebral hemorrhage.