title: The role of tetraspanin CD9 in osteoarthritis using three different mouse models.
abstract: Although osteoarthritis (OA) is the most prevalent aging-related joint disease, the understanding of mechanisms of OA pathogenesis remains limited. Key features include the progressive degradation of articular cartilage, synovial hyperplasia, and angiogenesis in joint tissues. CD9, a member of the tetraspanin family, is localized in the cell membranes and partly in the endosomes of all mammalian cell types. CD9 is associated with inflammation and angiogenesis through cell adhesion, migration, and signal transduction. This study examined the role of CD9 in OA development in three different mouse models: an aging model, a surgical model and antigen-induced arthritis (AIA) model, using CD9 deficient mice. Our study showed that CD9 deficiency reduced the severity of hallmarks of OA including cartilage degradation and soft tissue inflammation in aged mice. In the AIA model, cartilage damage and inflammation were also reduced in CD9-/-mice. This was in contrast to the surgical OA model where disease severity was similar in wild-type and CD9-/-mice. Col2a1 and Aggrecan expression was increased in chondrocytes of CD9-/-mice compared with those of wild-type mice. Our results indicate that the suppression of cartilage degradation in CD9-/-could be in part related to an increase in the expression of the two main cartilage extracellular matrix proteins aggrecan and type II collagen.
authors: Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University.
authors: Norihiko
authors: N
authors: Sumiyoshi
authors: Hiroyuki
authors: H
authors: Ishitobi
authors: Shigeru
authors: S
authors: Miyaki
authors: Kenji
authors: K
authors: Miyado
authors: Nobuo
authors: N
authors: Adachi
authors: Mitsuo
authors: M
authors: Ochi
mesh_terms: D000367:Age Factors; D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D019902:Chondrocytes / Q000378:metabolism; D024043:Collagen Type II / Q000378:metabolism; D004195:Disease Models, Animal; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007719:Knee Joint / Q000378:metabolism / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D010003:Osteoarthritis / Q000209:etiology / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D011509:Proteoglycans / Q000378:metabolism; D060245:Tetraspanin 29 / Q000235:genetics* / Q000378:metabolism*
chemical_list: D024043:Collagen Type II; D016326:Extracellular Matrix Proteins; D018836:Inflammation Mediators; D011509:Proteoglycans; D060245:Tetraspanin 29