OBJECTIVE: The objective of this study was to examine PKC isozyme expression in human articular chondrocytes and assess roles for RACK1, a receptor for activated C kinase in the mechanotransduction process.
METHODS: Primary cultures of human articular chondrocytes and a human chondrocyte cell line were studied for expression of PKC isozymes and RACK1 by western blotting. Following mechanical stimulation of chondrocytes in vitro in the absence or presence of anti-integrin antibodies and RGD containing oligopeptides, subcellular localization of PKCalpha and association of RACK1 with PKCalpha and beta1 integrin was assessed.
RESULTS: Human articular chondrocytes express PKC isozymes alpha, gamma, delta, iota, and lambda. Following mechanical stimulation at 0.33Hz chondrocytes show a rapid, beta1 integrin dependent, translocation of PKCalpha to the cell membrane and increased association of RACK1 with PKCalpha and beta1 integrin.
CONCLUSIONS: RACK1 mediated translocation of activated PKCalpha to the cell membrane and modulation of integrin-associated signaling are likely to be important in regulation of downstream signaling cascades controlling chondrocyte responses to mechanical stimuli.
|Number of pages||8|
|Journal||Osteoarthritis and Cartilage|
|Publication status||Published - Nov 2002|
- Aged, 80 and over
- Cartilage, Articular
- Cell Line
- Integrin beta Chains
- Mechanotransduction, Cellular
- Middle Aged
- Protein Kinase C
- Receptors, Cell Surface