title: Osteoarthritis: differential expression of matrix metalloproteinase-9 mRNA in nonfibrillated and fibrillated cartilage.
abstract: Expression of matrix metalloproteinase-9 mRNA in osteoarthritic and normal cartilage was analyzed using reverse transcription-polymerase chain reaction and in situ hybridization. Fifty-four osteoarthritic cartilage samples were obtained from 24 patients undergoing total knee arthroplasty. Sixteen normal cartilage samples were obtained from non-osteoarthritic knees of four autopsy cases. With normal cartilage, reverse transcription-polymerase chain reaction analysis for matrix metalloproteinase-9 mRNA showed that chondrocytes exhibited only a trace signal. In analysis of osteoarthritic cartilage, chondrocytes of moderately and severely fibrillated cartilage exhibited a 73-fold and 110-fold increase in matrix metalloproteinase-9 mRNA signal, respectively, relative to normal cartilage. Chondrocytes of nonfibrillated osteoarthritic cartilage exhibited a 6-fold increase (p < 0.02) in matrix metalloproteinase-9 mRNA signal relative to normal cartilage. Analysis of matrix metalloproteinase-9 mRNA expression in fresh-frozen sections of normal and osteoarthritic cartilage by in situ hybridization confirmed these results. This study showed that reverse transcription-polymerase chain reaction provides a sensitive index of mRNA levels in normal and osteoarthritic cartilage samples and suggests that increased expression of matrix metalloproteinase-9 precedes fibrillation of cartilage in the development of osteoarthritis.
authors.affiliation: Orthopaedic Research Laboratory, Stanford University School of Medicine, California, USA.
authors.forename: K
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: W J
authors.initials: WJ
authors.lastname: Maloney
authors.forename: T
authors.initials: T
authors.lastname: Vu
authors.forename: A R
authors.initials: AR
authors.lastname: Hoffman
authors.forename: P
authors.initials: P
authors.lastname: Huie
authors.forename: R
authors.initials: R
authors.lastname: Sibley
authors.forename: D J
authors.initials: DJ
authors.lastname: Schurman
authors.forename: R L
authors.initials: RL
authors.lastname: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D017364:Collagenases / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D020780:Matrix Metalloproteinase 9; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017364:Collagenases; D020780:Matrix Metalloproteinase 9