Otro
Osteoblast Adhesion Dynamics: A Possible Role for ROS and LMW-PTP
Registro en:
Journal Of Cellular Biochemistry. Hoboken: Wiley-blackwell, v. 115, n. 6, p. 1063-1069, 2014.
0730-2312
10.1002/jcb.24691
WOS:000334523300006
Autor
Fernandes, Gustavo V. O.
Cavagis, Alexandre D. M.
Ferreira, Carmen V.
Olej, Beni
Leao, Mauricio de Souza
Yano, Claudia L.
Peppelenbosch, Maikel
Granjeiro, Jose Mauro
Zambuzzi, Willian F.
Resumen
Reactive oxygen species (ROS) modulate a variety of intracellular events, but their role in osteoblast adhesion and spreading remains unclear. ROS is a very-known physiological modulators of Protein Tyrosine Phosphatases activities, mainly to low molecular weight protein tyrosine phosphatase (LMW-PTP) activity. As this biological mechanism is not clear in osteoblast adhesion, we decided to investigate ROS levels and phosphorylations of FAK and Src, identifying these proteins as potential substrates to LMW-PTP activity. Our results showed that during osteoblast adhesion/spreading (30min and 2h of seeding) the intracellular ROS content (hydrogen peroxide) is finely regulated by an effective anti-oxidant system [catalase and Superoxide Dismutase (SOD) activities were evaluated]. During the first 30min of adhesion, there was an increase in ROS production and a concomitant increase in focal adhesion kinase (FAK) activity after its phosphorylation at Tyrosine 397 (Y-397). Moreover, after 2h there was a decrease in ROS content and FAK phosphorylation. There was no significant change in LMW-PTP expression at 30min or 2h. In order to validate our hypothesis that LMW-PTP is able to control FAK activity by modulating its phosphorylation status, we decided to overexpress and silence LMW-PTP in this context. Our results showed that FAK phosphorylation at Y-397 was increased and decreased in osteoblasts with silenced or overexpressed LMW-PTP, respectively. Together, these data show that ROS modulate FAK phosphorylation by an indirect way, suggesting that a LMW-PTP/FAK supra-molecular complex is involved in transient responses during osteoblast adhesion and spreading. J. Cell. Biochem. 115: 1063-1069, 2014. (c) 2013 Wiley Periodicals, Inc. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)