Disruption of actin cytoskeleton induces chondrogenesis of mesenchymal cells by activating protein kinase C-alpha signaling

Biochem Biophys Res Commun. 2000 Jul 5;273(2):609-13. doi: 10.1006/bbrc.2000.2987.

Abstract

Disruption of actin cytoskeleton with cytochalasin D has been known to induce chondrogenic differentiation of chick embryo limb bud mesenchymal cells. However, the mechanism(s) for the induction of chondrogenesis by cytochalasin D is not yet clearly known. In the present study, we examined possible involvement of protein kinase C (PKC) and extracellular signal-regulated protein kinase (Erk-1) in chondrogenesis of mesenchymal cells induced by disruption of actin cytoskeleton. Disruption of actin cytoskeleton with cytochalasin D or latrunculin B induced chondrogenesis of mesenchymal cells cultured at subconfluent cell density, as determined by type II collagen expression. Among the expressed PKC isoforms, cytochalasin D dramatically increased expression and activation of PKCalpha in a dose-dependent manner, and inhibition or downregulation of PKCalpha blocked cytochalasin D-induced chondrogenesis. Cytochalasin D also downregulated Erk-1 phosphorylation that is associated with chondrogenesis. Our results, therefore, suggest that disruption of actin cytoskeleton induces chondrogenesis of mesenchymal cells by activating PKCalpha and by inhibiting Erk-1 signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Cells, Cultured
  • Chick Embryo
  • Chondrogenesis / drug effects
  • Chondrogenesis / physiology*
  • Cytochalasin D / pharmacology
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism*
  • Isoenzymes / metabolism*
  • Mesoderm / cytology
  • Mesoderm / drug effects
  • Mesoderm / metabolism
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases / metabolism
  • Protein Kinase C / metabolism*
  • Protein Kinase C-alpha
  • Signal Transduction / drug effects

Substances

  • Actins
  • Isoenzymes
  • Cytochalasin D
  • Protein Kinase C
  • Protein Kinase C-alpha
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases