title: Transforming growth factor beta 1 regulates tissue inhibitor of metalloproteinases-1 expression in differentiated human articular chondrocytes.
abstract: OBJECTIVE
  To investigate the role of interleukin-6 (IL-6) and transforming growth factor beta 1 (TGF beta 1) in the regulation of tissue inhibitor of metalloproteinases-1 (TIMP-1) synthesis in human articular chondrocytes.
  
  
  METHODS
  Articular cartilage was obtained from human knee joints 24 hours after death. Chondrocytes were isolated by collagenase digestion and embedded in low-gelling-temperature agarose. After stimulation by cytokines, total RNA was isolated and analyzed by Northern blotting. TIMP-1 protein levels were determined using a competitive enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Human chondrocytes in agarose culture expressed messenger RNA (mRNA) for the IL-6 receptor (gp80) and its signal-transducing subunit gp130. In contrast to the findings in a previous study, IL-6 did not stimulate TIMP-1 expression in these cells, whereas TGF beta 1 was an important inducer of TIMP-1 mRNA and protein synthesis.
  
  
  CONCLUSIONS
  Our findings suggest that TGF beta 1 has a protective effect on the extracellular matrix of human articular chondrocytes.
authors.affiliation: Institut für Biochemie, Rheinisch-Westfälischen Technischen Hochschule (RWTH), Aachen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Günther
authors.forename: H D
authors.initials: HD
authors.lastname: Haubeck
authors.forename: E
authors.initials: E
authors.lastname: van de Leur
authors.forename: J
authors.initials: J
authors.lastname: Bläser
authors.forename: S
authors.initials: S
authors.lastname: Bender
authors.forename: I
authors.initials: I
authors.lastname: Gütgemann
authors.forename: D C
authors.initials: DC
authors.lastname: Fischer
authors.forename: H
authors.initials: H
authors.lastname: Tschesche
authors.forename: H
authors.initials: H
authors.lastname: Greiling
authors.forename: P C
authors.initials: PC
authors.lastname: Heinrich
mesh_terms: D000293:Adolescent; D000328:Adult; D015152:Blotting, Northern; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D015850:Interleukin-6 / Q000502:physiology; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D012333:RNA, Messenger / Q000378:metabolism; D018123:Receptors, Interleukin / Q000378:metabolism; D019947:Receptors, Interleukin-6; D019714:Tissue Inhibitor of Metalloproteinases; D016212:Transforming Growth Factor beta / Q000494:pharmacology / Q000502:physiology*
chemical_list: D006023:Glycoproteins; D015850:Interleukin-6; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D019714:Tissue Inhibitor of Metalloproteinases; D016212:Transforming Growth Factor beta; D008666:Metalloendopeptidases