title: Integrin signaling and cell spreading alterations by rottlerin treatment of chick limb bud mesenchymal cells.
abstract: Endochondral skeletal development begins with the formation of a cartilaginous template where mesenchymal cells aggregate and increase in density prior to their overt differentiation into chondrocytes. Prechondrogenic condensation, in which mesenchymal cells aggregate, requires cell migration and proliferation. However, the molecular mechanisms promoting this aggregation remain to be elucidated. Here, we report that rottlerin suppresses migration and cell surface expression of integrin beta1 in chondrogenic progenitors. Perturbation of integrin beta1 function using an anti-integrin beta1 blocking antibody suppressed the migration of wing bud mesenchymal cells. Furthermore, phosphorylation levels of Src and focal adhesion kinase (FAK) were decreased by rottlerin treatment. Cell treatment with PP2, an inhibitor of Src family kinase, or electroporation of FAK specific siRNA, suppressed cell migration in a wound-healing assay. Cells treated with rottlerin showed decreased phosphorylation of Akt, independent of PKCdelta inhibition. In addition, an Akt inhibitor suppressed the migration of chick limb bud mesenchymal cells. Taken together, our results point to the novel finding that rottlerin may act as a negative regulator for cell migration, an essential step for prechondrogenic condensation, by regulating integrin beta1 signaling at focal adhesion complexes via modulation of Akt activity.
authors.affiliation: Department of Biological Sciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Young-Ae
authors.initials: YA
authors.lastname: Choi
authors.forename: Dong-Kyun
authors.initials: DK
authors.lastname: Kim
authors.forename: Shin-Sung
authors.initials: SS
authors.lastname: Kang
authors.forename: Jong-Kyung
authors.initials: JK
authors.lastname: Sonn
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Jin
mesh_terms: D000098:Acetophenones / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001578:Benzopyrans / Q000494:pharmacology*; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D019012:Integrin beta1 / Q000378:metabolism*; D018878:Limb Buds / Q000166:cytology*; D008648:Mesoderm / Q000166:cytology*; D010766:Phosphorylation / Q000187:drug effects; D051745:Protein Kinase C-delta / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000098:Acetophenones; D001578:Benzopyrans; D004791:Enzyme Inhibitors; D019012:Integrin beta1; C085746:rottlerin; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019061:src-Family Kinases; D051057:Proto-Oncogene Proteins c-akt; D051745:Protein Kinase C-delta