Protective Effect Of Drp1 And BAX Colocalization In Mitochondria In Cortical Neurons

Objective:To investigate the protective effects of Drp1 and BAX colocalization in mitochondria in apoptotic cortical neurons.Materials and Methods:In vitro,cortex neurons of newborn SD rat within 24 h cultivated were divided into blank group(group A),DMSO group(group B),sodium glutamate group(group C),Mdivi-1 pretreatment + sodium glutamate group(group D).Beta III tubulin and MAP2 fluorescence were used for identification test of neurons.JC-1 fluorescent probe was used to detecting mitochondrial membrane potential.Whole-cell extract,cytoplasm and the mitochondrial cytochrome C,Casapse-3,Drp1,p-Drp1 were detected by Western Blot.The expression of BAX and Drp1 and the distribution relationship among BAX,Drp1 and mitochondria were detected by immunofluorescence staining.Results:The fluorescence results of Beta III tubulin and MAP2 clearly showed the specific morphology of neurons.The results of JC-1 probe showed that there was no significant difference in mitochondrial membrane potential between group A and group B,and the mitochondrial membrane potential in group C and D were decreased,especially in group C.The conclusion of Western blot is that: in group C and D BAX,Drp1 and Caspase-3 in the total cell extractions,especially in group C,while the variation tendency of p-Drp1 and Drp1 was reversed.In the cytoplasm,BAX,Drp1,and Cyto-C were significantly increased in group C and D,especially in group C.Results of extract of mitochondrial showed tha BAX,Drp1 were obviously increased while Cyto-C was reduced in group C,and p-Drp1 expression was very low in each group.The results of fluorescence and Westen blot showed sametendency of Drp1 and BAX.With the increase of Drp1 and BAX expression,both of them located in the mitochondria and the trend become more obvious.Conclusion:Mitochondria,as one of the important organelles in cells,provided energy for cells,and the integrity of Mitochondrial membrane,a dynamic structure,was essential to the maintenance of cell homeostasis.During the process of neuron apoptosis,expression of BAX and phosphorylation of p-Drp1 increased.BAX and Drp1 gathered together in the mitochondria,increased the permeability of mitochondrial membrane,promoted mitochondrial division,reduced the mitochondrial membrane potential,promoted Cyto-C released from mitochondria and activated Caspase-3 which mediated apoptosis.Mdivi-1 inhibited phosphorylation of p-Drp1,decreased the colocalization of Drp1 and BAX in mitochondrial,stabilized mitochondrial membrane potential,inhibited the release of Cyto-C and activation of Caspase-3,protected cells from apoptosis induced by glutamate.