The Effect Of Exogenous Cytochrome C Upon The TGF-β1 And SMAD1/5/8 Of Mice Myocardium In The Sepsis

ObjectiveTo explore the effect of exogenous Cytochrome c upon septic myocardial damage, cardiac function and myocardial TGF-βsignaling pathway.Methods78 male kunming mice were randomly divided into sham group(Sham=25), sepsis group(CLP=25) and exogenous cytochrome c treatment group(T=25). Cecal ligationand puncture was used to reproduce mice sepsis model on the CLP group and group T,Sham group was opened obdomen and flipped appendix. 24 hours after operation, group T and Sham group and CLP group were respectively injected exogenous cyt c(20mg/kg) and 150μl saline via tail vein. 30min after injection,all mice were evaluated at 0, 6, 12 hour. Each time point five mice, myocardium was done histopathological examination, RT-PCR and Western-Blot experiments, detected the content of TGF-β1 and Smad1/5/8 protein. At 24h time point, heart tissues each group were detected by transmission electron microscope. Rest mice were observed the survival rate.Results(1) The general situation and the survival rates after operationThree groups of mice were awakened in postoperative 2h.Sham group of mice were the same as the normal mice and all survived in 72h. In postoperative 2h, CLP group of mice began to exhibit depressed, drowsiness, unresponsive, unactivated, afraid of the cold, vertical hair, anorexia, canthus secretion and diarrhea symptoms and so on, when 24h were more severe.24h and 72h mice survival rate was respective 78% and 44%. The experiment was in line animal model with sepsis. The symptoms of group T was better than CLP group. 24h and 72h mice survival rate was respective 89% and 67%.(2) Pathological changesOptical microscope: The myocardial tissue of sham group was tissue without obvious pathological changes. It was clear that the myocardial tissue of CLP group appear multifocal myocardial fiber fracture, acidophilic dgeneration, focal myocardial necrosis; Group T could see that the above changes was significantly lighter.Transmission electron microscope: The myocardial tissue of sham group could be a large number of rows of mitochondria, mitochondrial cristae were smooth and complete. The myocardial tissue of CLP group significantly increased mitochondria, disordered, some mitochondria cristae broken, dissolved, myocardial interstitial mononuclear cell infiltration could be seen. Group T was also partially visible above changes, hut lighter.(3) Hemodynamic changesAt different time points, LVSP, LVEDP, and LV±dp / dt-max of Sham group had no significant change (P >0.05). LVSP, LVEDP, and LV±dp / dt-max of CLP group gradually decreased at different time points, lower than all of Sham group (P <0.05). At all time points, the indicators of group T were on the rise, higher than CLP group (P <0.05).(4) Changes of TGF-β1 and Smad1/5/8 levelsRT-PCR and Western-Blot Detected that TGF-β1 and Smad1/5/8 protein of the myocardial tissue were expressed。protein expression of CLP group significantly increased。T group intervened by exogenous cytochrome c protein expression decreased。Compared with the other groups,the difference was statistically significant (P <0.05).ConclusionExogenous Cyt c can effectively reduce myocardial damage and improve cardiac function on the SIMD, this effect can be reduced myocardial expression of TGF-β1 to achieve by Smad1/5/8 pathway.