The role of Drp1 mediated mitochondrial dynamics balance in sepsis induced cardiomyopathy / 中华急诊医学杂志

ABSTRACT

Objective:To analyze the effect of inhibiting excessive mitochondrial fission mediated by dynamic related protein 1 (Drp1) on the function of injured cells and mitochondria in the septic myocardium, and to explore the protective effect of maintaining mitochondrial dynamic balance in the pathogenesis of sepsis induced cardiomyopathy(SIC).Methods:Rat H9C2 cardiomyocytes were cultured and stimulated with lipopolysaccharide (LPS) to establish a model of SIC. Mitochondrial division inhibitor 1 (Mdivi-1) was given 30 min before LPS stimulation. They were divided into the control group, LPS stimulated group (LPS), Mdivi-1 control group (Mdivi-1), and LPS+Mdivi-1 intervention group (LPS+Mdivi-1). CCK-8 was used to detect the cell viability, and lactate dehydrogenase (LDH) was used to detect cellular damage. A MitoTracker probe was used to observe mitochondrial morphology by laser scanning confocal microscopy, JC-1 staining was used to detect mitochondrial membrane potential level, a DCFH-DA probe was used to detect total ROS level, and an AnnexinV-FITC/PI probe was used to detect the cell apoptosis ratio. The expression levels of mitochondrial fission protein Drp1 and fusion proteins Optic Atrophy 1(Opa1) and Mitofusin2 (Mfn2) were detected by real-time PCR and Western blot. One-way ANOVA was used to compare the differences between groups, and the LSD- t test was used for pairwise comparisons between groups. Results:Compared with the control group, cell viability, the average length of mitochondria and the mitochondrial membrane potential were decreased, and ROS production, the cell apoptosis rate and LDH were increased in the LPS group (all P<0.05). After Mdivi-1 intervention, compared with the LPS-stimulated group, the cell viability was increased, myocardial cell damage was reduced, the average length of mitochondria was prolonged, mitochondrial dysfunction was alleviated, and the cell apoptosis rate was inhibited in the LPS+Mdivi-1 group (all P<0.05). Conclusions:Mdivi-1 might inhibit mitochondrial fission mediated by Drp1, maintain mitochondrial dynamic balance, alleviate mitochondrial dysfunction and protect myocardial cells from LPS-induced injury.