Effect of Transforming Growth Factor Beta (TGF Beta) and Vitamin D3 Metaboliteson Protein Kinase C Mediated Signal Transduction in Rat Costochondral Chondrocyte Cultures

摘要

It is Imown that vitamin D3 metabolites and transforming growth factor % (TOF-J3)regulate proliferation and differentiation of chondrocytes isolated from the growth zone or resting zone of rat costochondral cartilage. It was hypothesized that both TGF-% and the vitamin D metabolites play a role in signal transduction in the rat costochondral chondrocyte model and that the regulation of protein kinase C by these metabolites would be cell maturation-dependent. Confluent, fourth passage cultures of growth zone and resting zone chondrocytes were treated with vitamin D3 metabolites for up to 24 hours, lysed, and the cell extracts assayed for protein kinase C (PKC) specific activity using a specific peptide substrate. The addition of i,25-(OH)2D3 to growth zone chondrocyte cultures resulted in a rapid, dose dependent stimulation of PKC specific activity.