Expression of type X collagen in young and old C57Bl/6 and Balb/c mice. Relation with articular cartilage degeneration.
OBJECTIVE
To investigate whether the development of osteoarthritic lesions in the knee joints of mice is associated with increased immunostaining of type X collagen.


METHODS
Sections of total knee joints in combination with immunohistochemistry were used to study the distribution of type X collagen in the cartilage of young and old mice of two mouse strains, Balb/c and C57Bl/6, known to develop osteoarthritic lesions at different locations. Expression of type X collagen and PTH/PTHrP-receptor mRNA were studied by RT-PCR.


RESULTS
Young adult Balb/c and C57Bl/6 mice both expressed type X collagen in the non-calcified cartilage of the tibia-femoral joint. Old mice of both strains had a strongly increased deposition of type X collagen in the patella-femoral but not in the tibia-femoral joint. The locations in the murine knee joints prone to develop osteoarthritis (OA) did not preferentially express increased amounts of type X collagen. Thus, whereas increased type X was observed in both strains in the patella-femoral joints, only Balb/c mice preferentially developed osteoarthritic lesions in these joints. Also cartilage degeneration was usually seen only in the lateral compartment of the knee joints of C57Bl/6 mice but this was not accompanied by increased type X collagen immunostaining. Increased deposition of type X collagen was not associated with elevated levels of type X collagen mRNA or with decreased levels of PTH/PTHrP-receptor mRNA.


CONCLUSIONS
Type X collagen expression and spontaneous OA in mice are not necessarily related since OA prone locations in the murine knee joint do not preferentially express type X collagen.
van der Kraan
P M
PM
Department of Rheumatology, University Hospital Nijmegen, Geert Grooteplein 8, Nijmegen, 6525 GA, The Netherlands. P.vanderKraan@reuma.azn.nl
Stoop
R
R
Meijers
T H
TH
Poole
A R
AR
van den Berg
W B
WB
D000367:Age Factors; D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D003094:Collagen / Q000737:chemistry*; D006614:Hindlimb / Q000503:physiopathology; D007596:Joints / Q000503:physiopathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D020370:Osteoarthritis, Knee / Q000503:physiopathology*; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000737:chemistry
D012333:RNA, Messenger; D003094:Collagen