Effect of hepatocyte growth factor on the expression of apoptosis-inducing factor in infant rat brain injury induced by lipopolysaccharide

Objective To investigate the effects of hepatocyte growth factor( HGF) on the expression of apoptosis inducing factor(AIF) in infant rat brain injury induced by lipopolysaccharide(LPS) . Methods Two hundred and forty one-month-old healthy Spragne-Dawley(SD) rats were randomly divided into three groups:normal saline(NS) group(n = 80) ,LPS group(n = 80) ,HGF group(n = 80) . LPS(1 mg /kg) was injected via external carotid to establish the brain injury model. In HGF group,after injecting LPS,each rat was immediately treated with HGF(15-20 mg /kg) via common carotid artery. Evans blue(EB) content of brain tissue was meassured by the formamide methods,expression of AIF,neuron specific enolase( NSE) ,and glial fibrillary acidic protein( GFAP) were assessed with immunohistochemistry technology. Meanwhile,pathological changes of brain tissue were examined through light microscope. Results In LPS group,EB content in the brain,and levels of NSE,GFAP protein started to rise 6 h after LPS injection,reaching peak at 24 h. Levels of three indexes were all higher in this group at each time point compared with those in NS groups,the differences were significant(P 0.01) . And the expression of AIF was consistent with the degree of brain injury,increased at 6 h after LPS injection and peaked at 24 h. Positive correlation was found among AIF,and EB content,NSE protein,GFAP. Pathological changes of the brain tissue were notable. In HGF group,levels of AIF,EB content in the brain,NSE,and GFAP were decreased,the differences were significant compared with those in NS group(P 0.01) . The pathological changes of the brain tissue were unremarkable. Conclusions HGF could decrease the expression of AIF in infant rat brain injury induced by LPS,which might be one of the mechanisms of neuroprotection.