The Research Of How HO-1Regulate Nrf2-ARE Signaling Pathways Take Neuroprotection On Exprimental Intracerebral Hemorrhage

Objective and background:The secondary damage of intracerebral hemorrhage in perihematoma tissue isthe key factor for the outcome, the waterfall of inflammatory factors,free radical arecrucial factors to the secondary brain injure after intracerebral hemorrhage.Studiesshow that heme oxygenase1(HO-1) is widely expressed in the central nervecells(neurons and glial cells),which is an important downstream anti-oxidant anddetoxication protein of Nrf2-ARE signaling pathway,and has neuroprotection ofanti-inflammatory, anti-oxidant and anti-apoptosis.This study use zinc rotoporphyrin–IX,which is a selective inhibitor of HO-1,to inhibit the expression of HO-1,toobserve the expression of Nrf2-ARE pathway upstream and downstream protein suchas Nrf2,NF-κB， combined with neurological score.To explore the mechanism ofHO-1neuroprotection on peri-hematoma after ZPP-IX treatment,for providing a newexperimental basis for the treatment of intacerebral hemorrhage.Methods:Use auto-arteria cruralisblood injections to establish rat intracerebralhemorrhage model in basal ganglia,and divided into four groups： normal group,simple intracerebral hemorrhage group, ZPP-IX+ICH group, DMSO+ICH group.Toobserve the level of binding-nrf2(Nrf2-Keap1),Nrf2,HO-1,NF-κBp65,TNF-α proteinand mRNA around perihematoma,combined with neurological score,statistics andanalysis the data(ANOVA,t-test).Results:The expression of Nrf2,HO-1,NF-κB p65and TNF-α in the ICH groupupregulated at6h and reached its peak at48-72h compared to the normal group, andthe differences persist to7days.But the expression of binding-nrf2began to reduce at12h after ICH compared to normal group,and reduced obviously at48h(P<0.05).ZPP-IX aggravated neural dysfunction,and upregulated binding-Nrf2, NF-κBp65,TNF-α,downregulated Nrf2,HO-1,the difference is most obvious at48-72h.,and the differences persist to7days.The neurological score and earch protein expression ofDMSO+ICH group are no significant difference compared to ICH group.Conclusion:(1) HO-1shown a neuroprotective effect in the early stage after intrcerebralhemorrhage;(2) Nrf2-ARE signaling pathway began activate at6h after intracerebralhemorrhage, show in upregulate Nrf2and its downstream protein HO-1,this change isaccording with the rush hour of brain edema after ICH,raise the hypothesis thatNrf2-ARE signaling pathway has the neuroprotective effect on the secondary braindamage through against brain edema around the perihematoma,and is likely throughthe key protein of HO-1;(3) HO-1can inhibit inflammatory reaction by promotingthe upstream protein Nrf2dissociation and tansfer to the nucleus(that is activatedNrf2),and downregulated NF-κB p65and downstream factors after intracerebralhemorrhage.