title: MicroRNA-30a promotes chondrogenic differentiation of mesenchymal stem cells through inhibiting Delta-like 4 expression.
abstract: OBJECTIVE
  MicroRNAs (miRNAs) play important roles in chondrogenic differentiation of mesenchymal stem cells (MSCs). However, the regulation of miR-30a during such process has not yet been well understood. The aim of the study was to investigate the effects of miR-30a on chondrogenic differentiation of MSCs and explore the underlying mechanisms.
  
  
  METHODS
  MSCs were isolated from rat bone marrow, and their immunophenotypes and multilineage differentiation potentials were identified. MiR-30a mimics or inhibitor were transfected into rat MSCs and SW1353 cells, respectively, and then the effects of miR-30a on chondrogenic differentiation were detected. The predicted target gene Delta-like 4 (DLL4, a ligand of the Notch signaling family) was verified by luciferase reporter assay, quantitative real time PCR and western blot.
  
  
  RESULTS
  MiR-30a was significantly up-regulated during chondrogenic differentiation of rat MSCs. Additionally, transfection of miR-30a mimics remarkably promoted the differentiation of rat MSCs into chondrocytes as evidence by the notably increased mRNA and protein expression levels of chondrogenic markers Collagen II and aggrecan as well as the enhanced alcian blue staining intensity, whereas inhibition of miR-30a obviously suppressed such process. Furthermore, during chondrogenesis, DLL4 expression was found to significantly decrease at both mRNA and protein levels, which was negatively regulated by miR-30a through directly targeting the 3'UTR of DLL4.
  
  
  CONCLUSIONS
  Our results indicate that miR-30a acts as a key promoter for chondrogenic differentiation of MSCs by down-regulating DLL4 expression, and provide a novel insight on miRNA-mediated MSC therapy for cartilage-related disorders including osteoarthritis.
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China. Electronic address: tianyecmusjh@sina.com.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Ran
authors.initials: R
authors.lastname: Guo
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Shi
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Longgang
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Liqing
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Fu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis*; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D035683:MicroRNAs / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; D036341:Intercellular Signaling Peptides and Proteins; C546086:MIRN30b microRNA, human; D035683:MicroRNAs
keywords: Chondrogenesis; Delta-like 4 (DLL4); Mesenchymal stem cell (MSC); MiR-30a; MicroRNA