title: MicroRNA-21/PTEN/Akt axis in the fibrogenesis of biliary atresia.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are short, noncoding RNA molecules that act as post-transcriptional negative regulators of target mRNAs. Increasing evidence suggests that miRNAs are involved in liver fibrotic processes. Biliary atresia (BA) is characterized by rapid and progressive liver fibrosis. Therefore, we investigated the role of miRNA-21in the pathogenesis of BA.
  
  
  METHODS
  We collected liver samples from patients with BA or liver trauma to examine the role of miRNA-21. We examined RNA expression of miRNA-21, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and α-smooth muscle actin (α-SMA) in liver tissue using real-time fluorescence quantitative PCR. Western blot analyses and immunohistochemical staining were performed to evaluate protein expression of PTEN, α-SMA, and phosphorylated AKT in liver.
  
  
  RESULTS
  We found that miRNA-21was upregulated in liver samples from BA patients, whereas PTEN negatively correlated with suppression of the 3'-untranslated region (3'-UTR). Activation of the downstream AKT pathway provoked liver fibrosis by enhancing α-SMA levels.
  
  
  CONCLUSIONS
  The miRNA-21/PTEN/AKT axis promotes the fibrosis process in BA, which might be a potential therapeutic target to improve the prognosis of patients with BA.
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai 201102, China. Electronic address: doc_albert@126.com.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Shen
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai 201102, China. Electronic address: chengongzlp@hotmail.com.
authors.forename: Gong
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai 201102, China. Electronic address: dongrui_1982@126.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Dong
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai 201102, China. Electronic address: zhao007rui007@sina.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.affiliation: Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai 201102, China. Electronic address: szheng@shmu.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Zheng
mesh_terms: D020413:3' Untranslated Regions; D000199:Actins / Q000378:metabolism; D001656:Biliary Atresia / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; D000199:Actins; D035683:MicroRNAs; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human
keywords: Biliary atresia; Liver fibrosis; MicroRNA