Purchase this article with an account.
S. Tamiya, N.A. Delamere; Studies on the Role of Src–family Tyrosine Kinases in the Lens Equatorial Epithelium . Invest. Ophthalmol. Vis. Sci. 2005;46(13):1891.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Our previous study has shown that protein expression and the activity of Src–family kinases (SFKs) is higher at the equatorial region of the porcine lens epithelium compared to the anterior region (ARVO2004 abstract 1713). In this study, porcine lenses were cultured in the presence of a specific inhibitor of the SFKs in order to identify the potential role of these kinases in the equatorial region. Methods: The anterior and equatorial regions of the epithelium were collected separately and homogenized. Lenses were cultured in the presence of PP2, a specific inhibitor of SFKs, or a control compound PP3. For Western blots, homogenates were subjected to SDS–PAGE, transferred to nitrocellulose membranes, and probed for phospho–tyrosine and proliferating cell nuclear antigen (PCNA). Results: Phospho–tyrosine immunoblots revealed a greater abundance of tyrosine phosphorylated protein bands in the equatorial region of the porcine lens epithelium compared to the anterior region. In organ cultured lenses, PP2 reduced the density of multiple phospho–tyrosine protein bands compared to PP3 control. To study the potential influence of SFKs on proliferation, PCNA abundance was examined. PCNA was only detectable in the equatorial epithelium. PCNA abundance was significantly reduced in PP2–treated lenses compared to control. Conclusions: These results suggest that the higher Src–family kinase activity at the equatorial region contributes to the higher degree of protein phosphorylation observed in this region. Although the potential roles of tyrosine phosphorylation in the lens still need to be defined, the ability of PP2 to reduce PCNA abundance suggests that Src–family kinases play a role in control of lens cell proliferation.
This PDF is available to Subscribers Only