Osteoarthritis: differential expression of matrix metalloproteinase-9 mRNA in nonfibrillated and fibrillated cartilage.
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.
Tsuchiya
K
K
Orthopaedic Research Laboratory, Stanford University School of Medicine, California, USA.
Maloney
W J
WJ
Vu
T
T
Hoffman
A R
AR
Huie
P
P
Sibley
R
R
Schurman
D J
DJ
Smith
R L
RL
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
D012333:RNA, Messenger; D017364:Collagenases; D020780:Matrix Metalloproteinase 9