title: Obesity-Associated MiR-342-3p Promotes Adipogenesis of Mesenchymal Stem Cells by Suppressing CtBP2 and Releasing C/EBPα from CtBP2 Binding.
abstract: OBJECTIVE
  The elucidation of the molecular mechanism of adipocyte differentiation in mesenchymal stem cells is of essential importance for the development of treatments for metabolic diseases, such as obesity and diabetes.
  
  
  METHODS
  The expression levels of miR-342-3p and carboxy-terminal binding protein 2 (CtBP2) were regulated by oligonucleotide transfection. Adipogenic differentiation was induced by adipogenic medium containing indomethacin, dexamethasone and 3-isobutyl-1-methylxanthine on day 12, as determined by Oil Red O staining and triglyceride concentration assay to assess intracellular lipid accumulation. The induction of adipocyte-specific transcription factors and markers was detected by qRT-PCR and western blot. The regulation of CtBP2 expression by miR-342-3p was determined by western blot, qRT-PCR, luciferase reporter assay, ChIP assay and functional experiments.
  
  
  RESULTS
  We revealed that miR-342-3p was enriched in the adipose tissue of obese mice, and its expression was significantly elevated during adipogenic differentiation in both human mesenchymal stem cells (hMSCs) and 3T3L1 cells. Using gain- and loss-of-function assays, we demonstrated that the overexpression of miR-342-3p markedly promoted the differentiation of hMSCs into an adipogenic lineage. Adipogenesis was significantly blocked by miR-342-3p downregulation. We identified and validated that CtBP2 was a direct target of miR-342-3p in this process. The effects of the inhibition of CtBP2 were similar to those of miR-342-5p overexpression on adipogenic differentiation, promoting the release of C/EBPα from CtBP2 binding.
  
  
  CONCLUSIONS
  miR-342-3p is a powerful enhancer of the adipogenesis of human adipose-derived MSCs that acts by inhibiting CtBP2 and releasing the key adipogenic regulator C/EBPα from CtBP2 binding, subsequently activating the expression of adipogenic transcription factors and markers.
authors.affiliation: Shengli Oilfield Central Hospital, Dongying, Shandong, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Min
authors.initials: M
authors.lastname: Xu
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Xing
authors.forename: Caifeng
authors.initials: C
authors.lastname: Sun
authors.forename: Huifang
authors.initials: H
authors.lastname: Ding
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism; D050156:Adipogenesis / Q000235:genetics*; D000273:Adipose Tissue / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D002478:Cells, Cultured; D056970:Co-Repressor Proteins; D015536:Down-Regulation / Q000235:genetics; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D051379:Mice; D008820:Mice, Obese; D035683:MicroRNAs / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics*
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; C515848:CEBPA protein, human; D056970:Co-Repressor Proteins; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D000429:Alcohol Oxidoreductases; C421248:CTBP2 protein, human