title: MicroRNA-320 regulates matrix metalloproteinase-13 expression in chondrogenesis and interleukin-1β-induced chondrocyte responses.
abstract: OBJECTIVE
  Metalloproteinases (MMPs) are key regulators of osteoarthritis (OA) and collagen degradation and have been shown to participate in endochondral ossification. The aim of this study was to determine whether microRNA-320 (miR-320) regulates the expression of MMP-13 in chondrogenesis and inflammation.
  
  
  METHODS
  miR-320 expression was assessed in vitro, in the ATDC5 cell model of chondrogenesis and in interleukin-1β (IL-1β)-treated primary mouse chondrocytes (PMCs), and in vivo, in normal and OA human cartilage by in situ hybridization. ATDC5 and PMCs were transfected with miR-320 or its antisense inhibitor (anti-miR-320), respectively. The roles of activated MAP kinases (MAPK) and NF-κB were evaluated by using specific inhibitors. Direct interaction between miR-320 and its putative binding site in the 3'-untranslated region (3'-UTR) of Mmp-13 mRNA was confirmed by the luciferase reporter assay.
  
  
  RESULTS
  miR-320 expression was elevated in chondrogenic and hypertrophic ATDC5, while significantly reduced in OA cartilage compared with normal cartilage. Stimulation with IL-1β led to a significant reduction in miR-320 expression in PMCs. Upregulation of MMP-13 expression was correlated with downregulation of miR-320 expression in both PMCs and ATDC5. Overexpression of miR-320 suppressed the activity of a reporter construct containing the 3'-UTR and inhibited MMP-13 expression in both ATDC5 and IL-1β-treated PMCs, while treatment with anti-miR-320 enhanced MMP-13 expression. NF-κB and MAPK activation downregulated miR-320 expression.
  
  
  CONCLUSIONS
  Cartilage development and homeostasis are influenced by miR-320, which directly targets MMP-13 and regulates chondrogenesis and the IL-1β-stimulated catabolic effect in mouse chondrocytes.
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: F
authors.initials: F
authors.lastname: Meng
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: G
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: A
authors.initials: A
authors.lastname: He
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: C
authors.initials: C
authors.lastname: Hou
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Long
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China. Electronic address: zhzhiqi@163.com.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China. Electronic address: liaowmsysu@163.com.
authors.forename: W
authors.initials: W
authors.lastname: Liao
mesh_terms: D000368:Aged; D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism*; D020219:Chondrogenesis / Q000235:genetics* / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism*; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000502:physiology*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D053583:Interleukin-1beta; C572916:MIRN320 microRNA, human; D035683:MicroRNAs; C541056:Mirn320 microRNA, mouse; D012333:RNA, Messenger; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13; C507081:Mmp13 protein, mouse
keywords: Chondrocytes; Chondrogenesis; Metalloproteinase-13; MiRNA-320; Osteoarthritis