To investigate the mechanisms of enhancing effect by cAMP and staurosporine on chondrogenesis, cultures of HH-stage 23/24 chick embryo limb bud mesenchymal cells were treated with cAMP, staurosporine or PMA on different culture days and quantitative a...
To investigate the mechanisms of enhancing effect by cAMP and staurosporine on chondrogenesis, cultures of HH-stage 23/24 chick embryo limb bud mesenchymal cells were treated with cAMP, staurosporine or PMA on different culture days and quantitative analysis of chondrogenesis and morphological study were employed. Staurosporine showed chondrogenic effect in any time during the culture. In the cross section of staurosporine treated micromass cultures, larger and denserly Alcine blue stained nodules were observed. Several other inhibitors of PKC or protein tyrosine kinase did not show any significant effect on chondrogenesis. Chondrogenesis was promoted when cAMP was added to the cultures after 1 day of culture but there was no clear nodule in cAMP treated cultures. These data indicate that staurosporine promoted chondrogenesis by inducing cell condensation during the early stage of differentiation and cAMP affects chondrogenesis after cell condensation possibly by modulating gap junctional communication.