On the road to understanding of the osteoblast adhesion: cytoskeleton organization is rearranged by distinct signaling pathways.
Pre-osteoblast adhesion attracts increasing interest in both medicine and dentistry. However, how this physiological event alters osteoblast phenotype is poorly understood. We therefore attempted to address this question by investigating key biochemical mechanism that governs pre-osteoblast adhesion on polystyrene surface. Importantly, we found that cofilin activity was strongly modulated by PP2A (Ser/Thr phosphatase), while cell-cycle was arrested. Accordingly, we observed that the profile of cofilin phosphorylation (at Ser03) was similar to phospho-PP2A (at Tyr307). Also, it is plausible to suggest during pre-osteoblast adhesion that PP2A phosphorylation at Y307 was executed by phospho-Src (Y416). In addition, it was observed that MAPKp38, but not MAPK-erk, played a key role on pre-osteoblast adhesion by phosphorylating MAPKAPK-2 and ATF-2 (also called CRE-BP1). Also, the up-modulation of RhoA reported here suggests its involvement at the beginning of osteoblast attachment, while Akt remained active during all periods. Altogether, our results clearly showed that osteoblast adhesion is under an intricate network of signaling molecules, which are responsible to guide their interaction with substrate mainly via cytoskeleton rearrangement.
Zambuzzi
Willian Fernando
WF
Department of Biochemistry, Biology Institute, University of Campinas, Campinas, São Paulo, Brazil. wzamba@unicamp.br
Bruni-Cardoso
Alexandre
A
Granjeiro
José Mauro
JM
Peppelenbosch
Maikel Petrus
MP
de Carvalho
Hernandes Faustino
HF
Aoyama
Hiroshi
H
Ferreira
Carmen Veríssima
CV
D000818:Animals; D002448:Cell Adhesion; D002453:Cell Cycle; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D015398:Signal Transduction; D013912:Threonine / Q000235:genetics / Q000378:metabolism; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism; D000099190:MAP-Kinase-Activated Kinase 2
D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D013912:Threonine; D014443:Tyrosine; D000099190:MAP-Kinase-Activated Kinase 2