E3 Ligase Fbw7 Participates In Oxidative Stress Induced Myocardial Cell Injury Via Interacting With Mcl-1

Background:Oxidative stress participates in several heart diseases and it is known as an important mechanism of pathological changes of myocardial cell injury.Ubiquitylation,a significant biochemical reaction,is discovered as an apoptosis associated process in recent years.We discover that E3 ligase Fbw7 can facilitate apoptosis via Mcl-1-Bax pathway in oxidative stress induced myocardial cell?H9c2 cell?injury.Mcl-1 inhibits functions of other members in Bcl-2 family to maintain cell viability,but Fbw7 degrades Mcl-1 and impairs this process.Thus,we suppose that Fbw-7 co?Ld be a factor that promotes myocardial cell injury.Materials and Methods:We performed the study based on H9c2 rat myocardial cell line,and established oxidative stress model with H₂O₂.We tested viability,apoptosis rate,Fbw7/Mcl-1/Bax exprssion,and ROS accumulation of H9c2 cell with CCK-8,flow cytometry,Western Blot and ROS test respectively.Furtherly,we investigated the same indicators above after knocking down Fbw7,and tested molecular combination of Fbw7and Mcl-1 both under physical and oxidative stress injury state with co-immunoprecipitation.Images of Western Blot,FCM,ROS were processed by Photoshop 2017.Column graphs were disposed by Graphpad Prism?Ver 7.0.4?.Gray value analysis of Western Blot,ROS fluorescence were performed by ImageJ?Ver 1.8.0?.The statistical analysis was processed by SPSS?Ver 19.0?,the data were presented as M±SD,and independent-samples T test was applied to analyze significance,P<0.05indicated that the differences were settled as significant?*P<0.05;**P<0.01?.Results:Along with oxidative stress rises,H9c2 cell viability gets lower,and apoptosis rate elevates,expression of Fbw7 and Bax increase,whereas Mcl-1 decreases,intracellular ROS quantity accumulates gradually rises.After knocking down Fbw7,within the same oxidative stress state,H9c2 viability and apoptosis rate are alleviated,Fbw7 and Bax protein expression slide down,however,Mcl-1 expression bounces back,ROS accumulation is relatively inhibited in cells.Endogenous and exogenous co-immunoprecipitation indicate the Fbw7 and Mcl-1 combination under physical state,and the combination is enhanced while oxidative stress injury occurs.Conclusions:E3 ligase Fbw7 participates oxidative stress induced myocardial cell injury via interacting with Mcl-1.