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J. Cui, X.F. Wang, J.A. Matsubara; Increased Expression of VEGF and Other Angiogenic Factors Induced by Calcium–Mediated Dissociation of Retinal Pigment Epithelial Cells . Invest. Ophthalmol. Vis. Sci. 2004;45(13):1819.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: To determine the effects of calcium–mediated dissociation of retinal pigment epithelial (RPE) cells on gene expression of the angiogenesis–associated factors. Methods: Cultured human fetal RPE cells were used. Calcium–dependant cell–cell adhesions were disrupted by EGTA (4 mM) and low calcium medium (10 µM) respectively. Blocking antibodies of anti–E–cadherin (Clone 78–7) and N–cadherin (Clone GC–4) were also tested. Gene expression levels of VEGF and other angiogenic factors were quantified by real–time PCR. Results: Cellular adhesions of cultured RPE cells can be disrupted by EGTA and low calcium medium, but not by anti–E– and N–cadherin antibodies. The expression levels of VEGF substantially increased in the RPE cells treated with EGTA during 24 hrs, with a peak at 6 hr (7.7–fold). Low calcium medium induced a similar increase of VEGF expression (6.3–fold up at 6 hr). There are no obvious changes for the treatment of anti–cadherins’ antibodies. The changes of different splicing variants of VEGF were measured. VEGF121 and 165 increased obviously in the treatment of EGTA and low calcium medium, while VEGF145 and 189 were unchanged. VEGF206 was not detected in cultured RPE cells. Gene expression changes of some other angiogenic factors were also examined upon calcium–mediated cell dissociations. It has shown that the gene expression levels of bFGF, MMP–1, PDGF, PlGF increased, while that of aFGF and PEDF decreased in calcium–dependant dissociation of RPE cells. Conclusions: These findings show that calcium–mediated cell dissociation substantially affects the gene expression of VEGF and other angiogenic factors. It suggests that loss of cell–cell adhesions for RPE cells stimulates their production of angiogenic factors, and may contribute to the formation of choroidal neovascularization.
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