PloS one, 2012-09, Vol.7 (9), p.e43291
2012
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- Autor(en) / Beteiligte
- Titel
- Focal adhesion kinase plays a role in osteoblast mechanotransduction in vitro but does not affect load-induced bone formation in vivo
- Ist Teil von
- PloS one, 2012-09, Vol.7 (9), p.e43291
- Ort / Verlag
- United States: Public Library of Science
- Erscheinungsjahr
- 2012
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- A healthy skeleton relies on bone's ability to respond to external mechanical forces. The molecular mechanisms by which bone cells sense and convert mechanical stimuli into biochemical signals, a process known as mechanotransduction, are unclear. Focal adhesions play a critical role in cell survival, migration and sensing physical force. Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that controls focal adhesion dynamics and can mediate reparative bone formation in vivo and osteoblast mechanotransduction in vitro. Based on these data, we hypothesized that FAK plays a role in load-induced bone formation. To test this hypothesis, we performed in vitro fluid flow experiments and in vivo bone loading studies in FAK-/- clonal lines and conditional FAK knockout mice, respectively. FAK-/- osteoblasts showed an ablated prostaglandin E(2) (PGE(2)) response to fluid flow shear. This effect was reversed with the re-expression of wild-type FAK. Re-expression of FAK containing site-specific mutations at Tyr-397 and Tyr-925 phosphorylation sites did not rescue the phenotype, suggesting that these sites are important in osteoblast mechanotransduction. Interestingly, mice in which FAK was conditionally deleted in osteoblasts and osteocytes did not exhibit altered load-induced periosteal bone formation. Together these data suggest that although FAK is important in mechanically-induced signaling in osteoblasts in vitro, it is not required for an adaptive response in vivo, possibly due to a compensatory mechanism that does not exist in the cell culture system.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 1932-6203eISSN: 1932-6203DOI: 10.1371/journal.pone.0043291Titel-ID: cdi_plos_journals_1326551031
- Format
- –
- Schlagworte
- Adaptation, Biological - genetics, Adhesion, Animals, Binding sites, Biocompatibility, Biology, Biomedical engineering, Biomedical materials, Body Weight - genetics, Bone and Bones - metabolism, Bone growth, Cell adhesion & migration, Cell culture, Cell Line, Cell survival, Dinoprostone - metabolism, Engineering, Female, Fluid dynamics, Fluid flow, Focal adhesion kinase, Focal Adhesion Kinase 2 - metabolism, Focal Adhesion Protein-Tyrosine Kinases - genetics, Focal Adhesion Protein-Tyrosine Kinases - metabolism, Focal Adhesions - genetics, Gene Deletion, Gene Expression, In vivo methods and tests, Kinases, Loading, Male, Mechanical engineering, Mechanical loading, Mechanical stimuli, Mechanotransduction, Mechanotransduction, Cellular - genetics, Mice, Mice, Knockout, Molecular modelling, Motility, Mutation, Osteoblasts, Osteoblasts - metabolism, Osteocytes, Osteogenesis, Osteogenesis - genetics, Phosphorylation, Prostaglandin E2, Protein Transport, Protein-tyrosine kinase, Proteins, R&D, Rehabilitation, Research & development, Rodents, Signal transduction, Signaling, Skeleton, Tissue engineering, Tyrosine, Ulna - anatomy & histology, Ulna - metabolism, Veterans