title: [Myocardial cells and mitochondrial autophagy in sepsis mice induced by lipopolysaccharide].
abstract: OBJECTIVE
  To investigate the alterations in the level of myocardial cells and mitochondrial autophagy during myocardial injury in lipopolysaccharide (LPS)-induced septic animal models.
  
  
  METHODS
  Male C57BL/J mice were randomly divided into negative control group (NC), LPS treatment groups (6, 12, 24, 36 hours). The LPS treatment groups were subjected to LPS (10 mg/kg) injection intraperitoneally, and the NC group was injected intraperitoneally with the same amount of saline. The mice were sacrificed at the above time points to collect blood and heart tissues. Cytoplasmic protein, mitochondria and mitochondrial proteins were extracted from the myocardial tissue, and other myocardial tissue was frozen for next analysis. Cardiac troponin I (cTnI) levels in sera were evaluated by ELISA; mitochondrial membrane potential (MMP) was tested by JC-1 staining and fluorescence cytometry at different time points after LPS intraperitoneal injection. Furthermore, the levels of autophagy-related proteins such as microtubule-associated protein 1 light chain 3 (LC3), PTEN-induced kinase 1 (pink1), E3-ubiquitin ligase parkin were measured by Western blotting and fluorescent immunohistochemistry.
  
  
  RESULTS
  Compared with the control group, the serum levels of cTnI induced by LPS were significantly higher as 6 hours, while the MMP was significantly lower in the LPS treatment groups, and the lowest was in the 12-hour group. The expression of autophagy-related protein LC3-II/LC3-I significantly increased in the LPS 12-hour treatment group, pink1/parkin was significantly elevated in the LPS 6-hour treatment group, and they then gradually decreased.
  
  
  CONCLUSIONS
  The autophagy stress is activated in myocardium during myocardial injury induced by LPS treatment and it probably happens earlier at myocardial mitochondria.
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Pin
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Department of Orthopedics, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Jinjian
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Xijuan
authors.initials: X
authors.lastname: Peng
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Lanlan
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of ICU, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China. *Corresponding author, E-mail: yaolin@fmmu.edu.cn.
authors.forename: Linong
authors.initials: L
authors.lastname: Yao
mesh_terms: D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D007274:Injections, Intraperitoneal; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008869:Microtubule-Associated Proteins; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D011494:Protein Kinases / Q000378:metabolism; D018805:Sepsis / Q000097:blood / Q000139:chemically induced / Q000378:metabolism*; D013997:Time Factors; D019210:Troponin I / Q000097:blood; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism; D000099202:PTEN-Induced Putative Kinase
chemical_list: D008070:Lipopolysaccharides; D008869:Microtubule-Associated Proteins; D011494:Protein Kinases; D019210:Troponin I; D044767:Ubiquitin-Protein Ligases; D000099202:PTEN-Induced Putative Kinase; C480860:Map1lc3b protein, mouse; C111567:parkin protein