title: Taurine Reduced Epidural Fibrosis in Rat Models after Laminectomy via Downregulating EGR1.
abstract: OBJECTIVE
  Epidural fibrosis, a common complication after laminectomy, has been demonstrated to be closely associated with poor surgical outcomes. Previous studies showed that taurine had remarkable anti-fibrotic effects on lung and liver fibrosis. We performed this study to investigate the effects of taurine in rat models of epidural fibrosis after laminectomy and to explore the potential molecular mechanism.
  
  
  METHODS
  Laminectomy was performed on each rat to establish epidural fibrosis model. After taurine treatment, Masson's trichrome and immunohistochemistry staining were used to examine epidural fibrosis. Cell viability was determined using the Cell Counting Kit-8 assay. Annexin V/Propidium Iodide double staining was performed to detect fibroblasts apoptosis. Microarray was adopted to identify significantly changed mRNAs. mRNA expression was measured by qRT-PCR. Lentivirus infection was performed to establish stable knockdown and overexpression cell lines. The expression of fibrosis-related proteins was determined via Western blot.
  
  
  RESULTS
  Taurine treatment markedly reduced laminectomy-induced epidural fibrosis in rat models. However, this effect of taurine was independent on TGF-β/Smad pathway, evidenced by no change in the expression of TGF-β and its receptors. Besides, taurine had almost no effect on cell apoptosis. Interestingly, taurine treatment significantly decreased expression of EGR1 (Early growth response protein 1), an enhancer of fibrosis, both in vivo and in vitro. Furthermore, overexpression of EGR1 increased activation of fibroblasts, while EGR1 knockdown achieved an opposite effect, indicating that EGR1 plays a key role in the inhibitory effect of taurine on TGF-β-induced fibrosis.
  
  
  CONCLUSIONS
  Reduced epidural fibrosis in vivo and decreased activation of fibroblasts in vitro after taurine treatment was mediated by EGR1. Taurine promises to be a potential prevention for epidural fibrosis after laminectomy.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Tang
authors.forename: Hongtao
authors.initials: H
authors.lastname: Chen
authors.forename: Dawei
authors.initials: D
authors.lastname: Ge
authors.forename: Tao
authors.initials: T
authors.lastname: Sui
authors.forename: Jun
authors.initials: J
authors.lastname: Que
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Cao
authors.forename: Yingbin
authors.initials: Y
authors.lastname: Ge
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D015536:Down-Regulation; D051766:Early Growth Response Protein 1 / Q000235:genetics* / Q000378:metabolism; D004824:Epidural Space / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology*; D005355:Fibrosis; D007796:Laminectomy; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013654:Taurine / Q000627:therapeutic use*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D013654:Taurine