Qiliqiangxin Capsule Prevent Cardiac Failure After Myocardial Infarction By Repressing Stress-induced Premature Senescence

Objective We aimed to investigate the effect and mechanism of qiliqiangxin（QLQX）on ventricular remodeling after myocardial infarctionMethods In animal experiments,a mouse myocardial infarction model（MI）was established by ligating the left anterior descending artery（LAD）of 8-10 week-old male FVB/NJ mice,and then the mice were divided into 4 groups randomly:sham operation group;MI+QLQX group（0.25g/Kg/d）;MI+saline group;MI+myocardial cell CYLD protein high expression group.Gastrointestinal administration of medicine was started from the next day of the operation and last for 28 days.Echocardiography was performed to check the cardiac function of each group of mice;the cardiac tissue of the mice was sampled,and H&E and Masson staining were used to observe ventricular remodeling;RT-PCR was performed to access the m RNA profile of senescence associated secretory phenotype（SASP）IL-6,EREG,HGF,IL-1a,CXCL-1,CXCL-2 and MMP3;Western blot and immunohistochemistry were applied to detect the protein expression levels of senescence associated proteins such as p16,p53,PCNA;and m RNA and protein expression of CYLD was determinated using RT-PCR and Western blot individually.In vitro,H9C2 cell line was cultured,and the low and high expression of CYLD strainswas established by si RNA and transient transfection of the CYLD overexpression plasmid,respectively.Cells were treated with 10^-5mol/L H₂O₂for 3h,and then stained byβ-galactosidase to observe cell senescence;H9C2 cells were incubated with QLQX for 24hours and then treated with H₂O₂,Western blot was used to detect the expression of CYLD and p53 protein;RTCA and cell wound scratch test were used to detect the proliferation and migration of H9C2 cells.Results Animal experimental results:（1）The model of MI in mice was successfully established.Cardiac echo in mice showed that the MI+saline group had weakened movement,decreased left ventricular ejection fraction（LVEF）and left ventricular short axis shortening rate（LVFS）than the Sham group;while MI+QLQX group’s LVEF and LVFS were higher than MI+saline group（P<0.05）,and ventricular wall exercise ability were improved,suggesting that QLQX may improve cardiac function in mice.The heart function showed no difference between MI+CYLD^+/+group and MI+saline group;（2）H&E and Masson staining of myocardial tissue demonstrated QLQX improved the rearrangement of myocardium after myocardial infarction,reduced fibrosis（P<0.05）,and improved the ventricle Remodeling of mice,while high expression of CYLD protein can inhibit ventricular remodeling to a certain extent;（3）The m RNA level of SASP in the MI+saline group is increased when compaired with the sham group,while the MI+QLQX group is decreased from MI+saline group（P<0.05）,and Western immunoblotting and immunohistochemistry showed that the expression of p16 increased in MI tissue,and QLQX may attenuate this effect（P<0.05）;（4）MI decreased the expression of CYLD protein in cardiac tissue,while QLQX increase the expression of CYLD protein（P<0.05）.Compared with wild-type FVB MI mice,heart-specific high expression of CYLD in MI mice showed a decrease in SASP secretion and p53 expression,and a increase in PCNA expression,They have differences statistically（P<0.05）,implying that CYLD overexpression may slow down the stress aging process of MI tissue.Cell experiment results:（1）QLQX pretreated H9C2 cells increased CYLD protein expression（P<0.05）;（2）β-galactosidase staining showed there were more positive cells in H₂O₂induced si CYLD cells than in wild strains（P<0.05）,Western blot demonstrated the p53 expression was upregulated in wild-type H9C2 cells after H₂O₂treatment,with the highest expression in si CYLD and the least increase in QLQX pretreatment strain（P<0.05）;（3）RTCA experiment and cell wound scratch experiment showed the proliferation and migration of si CYLD cells slowed down,while CYLD overexpression strains increased.Conclusion（1）QLQX could improve ventricular remodeling after MI,and prevent cardiac dysfunction after MI in mice;（2）QLQX can delay stress aging of infarcted myocardium by increasing CYLD protein expression,Partly inhibit ventricular remodeling after MI and prevent the occurrence and development of heart failure.