title: miRNA studies in in vitro and in vivo activated hepatic stellate cells.
abstract: OBJECTIVE
  To understand which and how different miRNAs are implicated in the process of hepatic stellate cell (HSC) activation.
  
  
  METHODS
  We used microarrays to examine the differential expression of miRNAs during in vitro activation of primary HSCs (pHSCs). The transcriptome changes upon stable transfection of rno-miR-146a into an HSC cell line were studied using cDNA microarrays. Selected differentially regulated miRNAs were investigated by quantitative real-time polymerase chain reaction during in vivo HSC activation. The effect of miRNA mimics and inhibitor on the in vitro activation of pHSCs was also evaluated.
  
  
  RESULTS
  We found that 16 miRNAs were upregulated and 26 were downregulated significantly in 10-d in vitro activated pHSCs in comparison to quiescent pHSCs. Overexpression of rno-miR-146a was characterized by marked upregulation of tissue inhibitor of metalloproteinase-3, which is implicated in the regulation of tumor necrosis factor-α activity. Differences in the regulation of selected miRNAs were observed comparing in vitro and in vivo HSC activation. Treatment with miR-26a and 29a mimics, and miR-214 inhibitor during in vitro activation of pHSCs induced significant downregulation of collagen type I transcription.
  
  
  CONCLUSIONS
  Our results emphasize the different regulation of miRNAs in in vitro and in vivo activated pHSCs. We also showed that miR-26a, 29a and 214 are involved in the regulation of collagen type I mRNA.
authors: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos #04-01, Singapore 138669, Singapore.
authors: Gunter
authors: G
authors: Maubach
authors: Michelle Chin Chia
authors: MC
authors: Lim
authors: Jinmiao
authors: J
authors: Chen
authors: Henry
authors: H
authors: Yang
authors: Lang
authors: L
authors: Zhuo
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055166:Hepatic Stellate Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D017208:Rats, Wistar; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D024042:Collagen Type I; D035683:MicroRNAs; D016328:NF-kappa B; D019717:Tissue Inhibitor of Metalloproteinase-3; D014409:Tumor Necrosis Factor-alpha