| Objectives The aim of this study was to investigate the effects of Mdivi-1,a selective inhibitor of Drp1,on mitochondrial division/fusion,neuronal death,neurological deficits and learning and memory impairment in rats with intracerebral hemorrhage(ICH)secondary to in vitro and in vivo experiments,and to explore the underlying mechanisms with the aim of finding new therapeutic targets.Methods The rat ICH model was established by autologous arterial blood injection in the right basal ganglia region,and Mdivi-1 was injected by intraperitoneal injection at 30 min after ICH as the experimental group,and DMSO salt solution was injected accordingly as the control group.The rats were executed at different postoperative times,among which the brain tissue water content and behavioral treatment rats were executed at 3 d and 21 d postoperatively,respectively.in vitro Hemin induction method was used to construct the ICH cell model of neuronal injury.The changes of Drp1 and p-Drp1(Ser 616,Ser 637)protein content in rats after ICH were first assessed by immunoblotting(Western Blot)to select the peak phase of Drp1 and phosphorylated Drp1 expression as the observation point for subsequent experiments;Western blot and HE staining were applied to study the effect of different dose administration groups to screen the treatment Western blot and HE staining were applied to study the effect of different dose administration groups to screen the treatment dose.On the basis of the above experiments,HE,Nissl staining and brain water content were used to assess the hemorrhagic brain tissue injury in ICH rats.The expression of Drp1,p-Drp1(Ser 616),p-Drp1(Ser 637),Fis1 and Mfn1/2 were detected in the cytoplasm,mitochondria and isolated neuronal cells of rat brain tissue around the hematoma by Western blot.Finally,to assess whether the inhibitor Mdivi-1 improves the prognosis of rats after ICH through the above pathways,neurological function and spatial learning memory of rats after ICH were examined using neurological function score(m NSS)and behavioral assay(Morris water maze experiment).Results(1)Both Drp1 and p-Drp1(Ser 616)protein expression in the ICH group first increased from 1h to 6h and then decreased,and gradually rebounded at 12 h,and peaked at48 h.In contrast,p-Drp1(Ser 637)protein expression started to show a different trend at 24h(P<0.05).(2)Drp1 expression content was significantly reduced in the 3 mg/kg dose group compared with the ICH group,and HE-stained tissues showed reduced edema and fewer degenerated neurons(P<0.05).(3)The brain tissue around the hematoma showed edema,neuronal degeneration and inflammatory infiltration after ICH,and Mdivi-1 treatment significantly improved the extent of ICH-induced brain tissue injury(P<0.05).(4)ICH induced apoptosis of neurons,and Mdivi-1 was able to rescue neuronal death(P<0.05).(5)ICH induced changes in the expression of mitochondria-related proteins Drp1,p-Drp1(Ser616,Ser637),Fis1 and Mfn1/2,and Mdivi-1 treatment reversed these changes,but had no significant effect on Mfn1(P<0.05).(6)ICH caused alterations in neurological function and spatial learning memory dysfunction,and Mdivi-1 treatment reversed these alterations(P<0.05).Conclusions Mdivi-1 can improve neurological deficits and spatial learning memory impairment in ICH rats by specifically inhibiting Drp1 expression;its mechanism may be achieved by regulating the homeostasis of mitochondrial division/fusion homeostasis and inhibiting neuronal apoptosis,which may provide a new experimental basis and therapeutic strategy for the precise targeting of ICH.Figure 41;Table 0;Reference 110... |
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