Inhibition of tumor necrosis factor receptor associated factor 6 regulates mTORC1/ULK1 signaling and promotes autophagy to improve myocardial injury in sepsis mice
- VernacularTitle:抑制TRAF6调节mTORC1/ULK1信号通路促进自噬改善脓毒症小鼠的心肌损伤
- Author:
Ying ZHOU
1
;
Yong TIAN
;
Zhimei ZHONG
;
Yongxiang GU
;
Hao FANG
Author Information
- Publication Type:Journal Article
- Keywords: tumor necrosis factor receptor-associated factor 6; autophagy; sepsis; myocardial injury; mammalian target of rapamycin; engineered tissue construction
- From: Chinese Journal of Tissue Engineering Research 2025;29(30):6434-6440
- CountryChina
- Language:Chinese
- Abstract: BACKGROUND:Studies have found that inhibition of tumor necrosis factor receptor-associated factor 6 improves myocardial function and promotes myocardial autophagy in sepsis,but the specific mechanism is not clear.OBJECTIVE:To explore the effect of inhibiting tumor necrosis factor receptor-associated factor 6-regulated mTORC1/ULK1 autophagy signaling pathway on myocardial injury in sepsis mice.METHODS:Thirty male Kunming mice were randomly divided into sham operation group,cecal ligation and puncture group(model group),model+tumor necrosis factor receptor-associated factor 6 specific inhibitor C25-140(model+C)group,model+C25-140+autophagy inhibitor 3-methyladenine(model+C+3-MA)group,and model+C25-140+mTORC1-specific agonist MHY1485(model+C+M)group.The cecum of mice in the sham operation group was not ligated or punctured.The mice in the other groups underwent cecum ligation and puncture to establish the mouse sepsis model.C25-140,3-methyladenine,and MHY1485 were intraperitoneally injected 0.5 hours after surgery according to the grouping.Myocardial tissue was obtained 24 hours after surgery.Hematoxylin-eosin staining was used to evaluate myocardial inflammatory lesions.Transmission electron microscopy was used to observe the changes in the autophagic bodies and mitochondrial microstructures of myocardial cells.TUNEL assay was used to detect myocardial cell apoptosis.PCR was used to detect the relative expression of tumor necrosis factor receptor-associated factor 6 mRNA.Western blot assay was used to detect the expression of related proteins.RESULTS AND CONCLUSION:(1)Compared with sham operation group,myocardial inflammatory cell infiltration and fibrous edema were observed in the model group.The mitochondria of the cells were obviously swollen,and autophagosomes were occasionally seen;cardiomyocyte apoptosis increased significantly;the expression of tumor necrosis factor receptor-associated factor 6,phosphorylated nuclear factor κB P65/P65,p-mTOR/mTOR,p-ULK1/ULK1,P62 and Bax protein increased,and the expression of Bcl2 protein decreased(P＜0.05).(2)Compared with the model group,myocardial inflammation and fibrous edema were alleviated in the model+C group.Myocardial mitochondrial swelling was reduced and autophagosomes increased;cardiomyocyte apoptosis decreased;the expression of phosphorylated nuclear factor κB P65/nuclear factor-κB P65,p-mTOR/mTOR,p-ULK1/ULK1,P62,and Bax protein decreased,while the Beclin-1 and Bcl2 protein increased(P＜0.05).(3)Compared with the model+C group,myocardial autophagosomes decreased and myocardial mitochondrial swelling was more obvious in the model+C+3-MA group.Myocardial inflammation was aggravated;myocardial cell apoptosis increased;the expression of phosphorylated nuclear factor κB P65/nuclear factor κB P65,P62,and Bax protein increased,and the Beclin-1 and Bcl2 protein decreased(P＜0.05).(4)Compared with the model+C group,the expression of p-mTOR/mTOR and p-ULK1/ULK1 in the model+C+M group increased,and the Beclin-1 and microtubule-associated protein 1 light chain 3 Ⅱ/Ⅰ protein expression decreased(P＜0.05).It is concluded that inhibition of tumor necrosis factor receptor-associated factor 6 regulates mTORC1/ULK1 autophagy signal to promote myocardial autophagy and participate in the protection of myocardial injury in sepsis.
