Study About Expression Of HSP70 After Acute Spinal Cord Injury And Repair Of Acute Spinal Cord Injury By Geranylgeranylacetone

Objective To observe the expression of heat shock prtein 70(HSP70) after acute spinal cord injury(ASCI);and also observe the effect of a HSP70 inducer -Geranylgeranylacetone(GGA) on repairing of ASCI through up-regulation HSP70 expression in the earlier period after ASCI.Evaluation the functional recovery objectively in many ways to find an new effective way,which can be used in clinical practice easily,for providing an experimental evidence to clinical treatment of ASCI.Methods 1.The expression of HSP70 after acute spinal cord injury.50 healthy female Wistar rats were separated into two groups randomly(25 rats in each group ):Ⅰcontrol group,rats were exposed T10 spinal cord,but not injured by the impactor;Ⅱstudy group,rats were exposed T10 spinal cord,which were then injured by the impactor(10g×25mm).Rats were sacrificed 6,12,24,48,72 hours after the operation separativly,and the injured spinal cord were taken out for fix,slice,and Immunohistochemistry staining was used to determin HSP70 expression.2.The effect of GGA on expression of HSP70,apoptosis of neural cells and functional recovery after ASCI.75 healthy female Wistar rats were separated into three groups randomly(25 rats in each group):Ⅰcontrol group,Ⅱpost injury GGA administration group andⅢahead and post injury combined GGA administration group.Rats in groupⅠwere administrated equal saline by oral tube 24h ahead of injury,0.5h after injury and every 24h after injury until 1 week later;rats in groupⅡwere administrated equal saline 24h ahead of injury and GGA(600 mg/kg) 0.5h after injury and every 24h after injury until 1 week later;rats in groupⅢwere administrated GGA(600 mg/kg) on all the time points.Immunohistochemistry staining was used to determin HSP70 expression,TUNEL staining was used to detect the apoptosis level,HE staining and optics microscope was used to observe the histomorphology change of the spinal cord and the BBB(Basso,Beattie and Bresnahan) scales were used to evaluate hindlimb neurological function.Results 1.The expression level of HSP70 were upgraded rapidly after ASCI,the peak value were presented at 24h after injury,then the value decreased,and to be rare 72h after injury.In the control group,the expression of HSP70 was in a lower lever, and for a shorter period.2.The expression level of HSP70 among groups were statistically significance 12,24,48,72h after injury(ANOVA,P＜0.05),groupⅢandⅡexceed groupⅠ; the apoptosis level among groups were statistically significance 12,24,48,72h after injury(ANOVA,P＜0.05) too,groupⅢandⅡwere lower than groupⅠ.All the rats were inferior paraplegia after injury.The BBB score among groups were statistically significance since 7 days after injury(ANOVA,P＜0.05),groupⅢandⅡexceed groupⅠ.Conclusions The expression level of HSP70 was upgraded spontaneously.But the degree of it was limited,and the period of upregulation is deficient.GGA can increase the level of HSP70 expression,reduce the apoptosis of neural cells and promote the functional recovery after acute spinal cord injury.