title: Passaged human chondrocytes accumulate extracellular matrix when induced by bovine chondrocytes.
abstract: A source of sufficient number of cells is a major limiting factor for cartilage tissue engineering. To circumvent this problem, we developed a co-culture method to induce redifferentiation in bovine articular chondrocytes, which had undergone dedifferentiation following serial passage in monolayer culture. In this study we determine whether human osteoarthritic (OA) and non-diseased passaged dedifferentiated chondrocytes will respond similarly. Human passaged chondrocytes were co-cultured for 4 weeks with primary bovine chondrocytes and their redifferentiation status was determined. Afterwards the cells were cultured either independently or in co-culture with cryopreserved passaged cells for functional analysis. The co-culture of passaged cells with primary chondrocytes resulted in reversion of their phenotype towards articular chondrocytes, as shown by increased gene expression of type II collagen and COMP, decreased type I collagen expression and extracellular matrix formation in vitro. Furthermore, this redifferentiation was stable, as those cells not only formed hyaline-like cartilage tissue when grown on their own but also they could induce redifferentiation of passaged chondrocytes in co-culture. These data suggest that it may be possible to use autologous chondrocytes obtained from osteoarthritic cartilage to form tissue suitable to use for cartilage repair.
authors.affiliation: CIHR-BioEngineering of Skeletal Tissues Team, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Nazish
authors.initials: N
authors.lastname: Ahmed
authors.forename: Drew W
authors.initials: DW
authors.lastname: Taylor
authors.forename: Jay
authors.initials: J
authors.lastname: Wunder
authors.forename: Andras
authors.initials: A
authors.lastname: Nagy
authors.forename: Allan E
authors.initials: AE
authors.lastname: Gross
authors.forename: Rita A
authors.initials: RA
authors.lastname: Kandel
mesh_terms: D000818:Animals; D002417:Cattle; D002454:Cell Differentiation; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D018920:Coculture Techniques; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D010003:Osteoarthritis / Q000378:metabolism / Q000473:pathology; D016133:Polymerase Chain Reaction