Non-overlapping functions for Pyk2 and FAK in osteoblasts during fluid shear stress-induced mechanotransduction
| Autor: | Fredrick M. Pavalko, Suzanne R.L. Young, Charles H. Turner, Eric J. Rodenberg, Julia M. Hum |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: |
Integrins
Anatomy and Physiology lcsh:Medicine Mechanotransduction Cellular Focal adhesion Extracellular matrix 03 medical and health sciences Mice 0302 clinical medicine Bone cell Molecular Cell Biology medicine Cell Adhesion Animals Membrane Receptor Signaling Biomechanics Osteopontin Mechanotransduction lcsh:Science Biology Musculoskeletal System Cells Cultured 030304 developmental biology 0303 health sciences Multidisciplinary Osteoblasts biology Chemistry Skull Bone and Joint Mechanics lcsh:R Osteoblast Adhesion Focal Adhesion Kinase 2 Cell biology Extracellular Matrix medicine.anatomical_structure Biochemistry 030220 oncology & carcinogenesis Focal Adhesion Kinase 1 biology.protein Medicine lcsh:Q Stress Mechanical Rheology Research Article Signal Transduction |
| Zdroj: | PLoS ONE, Vol 6, Iss 1, p e16026 (2011) PLoS ONE |
| ISSN: | 1932-6203 |
| Popis: | Mechanotransduction, the process by which cells convert external mechanical stimuli such as fluid shear stress (FSS) into biochemical changes, plays a critical role in maintenance of the skeleton. We have proposed that mechanical stimulation by FSS across the surfaces of bone cells results in formation of unique signaling complexes called mechanosomes that are launched from sites of adhesion with the extracellular matrix and with other bone cells [1]. Deformation of adhesion complexes at the cell membrane ultimately results in alteration of target gene expression. Recently, we reported that focal adhesion kinase (FAK) functions as a part of a mechanosome complex that is required for FSS-induced mechanotransduction in bone cells. This study extends this work to examine the role of a second member of the FAK family of non-receptor protein tyrosine kinases, proline-rich tyrosine kinase 2 (Pyk2), and determine its role during osteoblast mechanotransduction. We use osteoblasts harvested from mice as our model system in this study and compared the contributions of Pyk2 and FAK during FSS induced mechanotransduction in osteoblasts. We exposed Pyk2(+/+) and Pyk2(-/-) primary calvarial osteoblasts to short period of oscillatory fluid flow and analyzed downstream activation of ERK1/2, and expression of c-fos, cyclooxygenase-2 and osteopontin. Unlike FAK, Pyk2 was not required for fluid flow-induced mechanotransduction as there was no significant difference in the response of Pyk2(+/+) and Pyk2(-/-) osteoblasts to short periods of fluid flow (FF). In contrast, and as predicted, FAK(-/-) osteoblasts were unable to respond to FF. These data indicate that FAK and Pyk2 have distinct, non-redundant functions in launching mechanical signals during osteoblast mechanotransduction. Additionally, we compared two methods of generating FF in both cell types, oscillatory pump method and another orbital platform method. We determined that both methods of generating FF induced similar responses in both primary calvarial osteoblasts and immortalized calvarial osteoblasts. |
| Databáze: | OpenAIRE |
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