title: [Release of HMGB1 by LPS-treated cardiac fibroblasts and its contribution to the production of collagen type  I   and    III].
abstract: OBJECTIVE
  To investigate whether cardiac fibroblasts (CFs) treated by LPS can actively secrete high-mobility group box protein 1 (HMGB1) and to analyze the correlation between HMGB1 releasing and the accumulation of collagen type  I ,  III .
  
  
  METHODS
  CFs were isolated from the heart of 7-14-day-old BALB/c mice and cultured in DMEM with 10% fetal bovine serum (FBS). We collected the CFs and cell supernatants after treated by LPS for 0, 6, 12, 24, 36, 48 h, respectively. The mRNA and protein expression levels of HMGB1, collagen 1a1 (col1a1) and collagen 3a1 (col3a1) in CFs after LPS stimulation were detected by RT-PCR and Western blotting, respectively. The intracellular localization of HMGB1 in treated CFs was investigated by immunofluorescence.
  
  
  RESULTS
  After 0-6 h of LPS stimulation, the mRNA levels of HMGB1, col1a1, col3a1 had no significant changes; but increased obviously at 12, 24, 36, 48 h. HMGB1 was found in the cell supernatant by Western blotting after 24  h LPS stimulation, and its expression decreased following the first rise in CFs. Meanwhile, immunofluorescence showed HMGB1 translocation from nucleus to cytoplasm. The levels of col1a1 and col3a1 were up-regulated in CFs after stimulation.
  
  
  CONCLUSIONS
  LPS can induce HMGB1 translocation from nucleus to cytoplasm and across cellular membrane to the outside of CFs at a time-dependent manner. Col1a1 and Col3a1, which are closely associated with myocardial fibrosis, were obviously up-regulated by LPS stimulation, which indicates that actively released HMGB1 might contribute to myocardial fibrosis following the endotoxin induced-sepsis.
authors.affiliation: Institute of Immunology, Jiangsu University, Zhenjiang, China. yinjingping1987@163.com
authors.forename: Jing-ping
authors.initials: JP
authors.lastname: Yin
authors.forename: Zhao-liang
authors.initials: ZL
authors.lastname: Su
authors.forename: Ying-mei
authors.initials: YM
authors.lastname: Wang
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Sha-sha
authors.initials: SS
authors.lastname: Tian
authors.forename: Xin-xin
authors.initials: XX
authors.lastname: Xu
authors.forename: Li-dan
authors.initials: LD
authors.lastname: Xing
authors.forename: Pan
authors.initials: P
authors.lastname: Zhang
authors.forename: Ke
authors.initials: K
authors.lastname: Ma
authors.forename: Hua-xi
authors.initials: HX
authors.lastname: Xu
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000096:biosynthesis* / Q000235:genetics; D024061:Collagen Type III / Q000096:biosynthesis* / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D024243:HMGB1 Protein / Q000235:genetics / Q000378:metabolism*; D042541:Intracellular Space / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D058628:Myofibroblasts / Q000187:drug effects / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D024243:HMGB1 Protein; D008070:Lipopolysaccharides