线粒体自噬-NLRP3炎症小体通路在新生大鼠缺血性 脑损伤中的作用研究.

Objective To investigate the effect of mitophagy-NOD-like receptor heat protein domain associated protein 3 (NLRP3) inflammasome pathway on cerebral ischemic injury in neonatal rats. Methods Forty-two 7-day SD rats were divided into the sham group, the cerebral ischemia-reperfusion injury (CIRI) group, the CIRI+dimethyl sulfoxide (DMSO) group, the CIRI+Mdivi-1 group, the CIRI+MCC950 group and the CIRI+Ac-YVAD-CMK group (7 rats in each group). Except for the sham group, the neonatal rat model of hypoxic-ischemic brain injury was established by unilateral common carotid artery occlusion. Neurological symptom score was performed by Londa method. Cell morphology in CA1 region of hippocampus was observed by hematoxylin-eosin (HE) staining. Ultrastructure of hippocampal neurons was observed by transmission electron microscopy, and related proteins of mitochondrial autophagy and NLRP3 inflammasome pathway were detected by Western blot assay. Results Compared with the CIRI+DMSO group, the CIRI+Mdivi-1 group had higher scores of neurobehavioral disorders, fewer synapses and more swollen mitochondria (all P＜0.05). Compared with the CIRI+Mdivi-1 group, the neurobehavioral disorder score and the number of synapses increased, and the number of swollen mitochondria decreased in the CIRI+MCC950 group and the CIRI+Ac-YVAD-cmk group (all P＜0.05). Compared with the CIRI+DMSO group, the protein expressions of PINK1, Parkin and LC3 Ⅱ/Ⅰ were down-regulated in the CIRI+ Mdivi-1 group, and the protein expressions of TOMM20, P62, NLRP3, caspase-1 and caspase-8 were up-regulated (P＜ 0.05). Compared with the CIRI+Mdivi-1 group, the protein expressions of PINK1, Parkin, LC3 Ⅱ/Ⅰ were up-regulated in the CIRI+MCC950 group and the CIRI+Ac-YVAD-cmk group (P＜0.05). The expression levels of NLRP3, caspase-1 and caspase-8 proteins were down-regulated in the CIRI+MCC950 group, and caspase-1 and caspase-8 proteins decreased in the CIRI+Ac-YVAD-cmk group (P＜0.05). Conclusion Activation of mitochondrial autophagy or inhibition of NLRP3 inflammasome activation have protective effects on cerebral ischemic injury in neonatal rats. [ABSTRACT FROM AUTHOR]