Abstract
Abstract: :
Purpose:Previous work from our laboratory has shown that activation of Phospholipase Cγ1 (PLCγ1) activation is required for tubulogenesis of endothelial cells and disruption of PLCγ1 binding with VEGFR–2/FLK–1 impairs the ability of VEGFR–2 to promote tubulogenesis in cell culture system. The present study is designed to evaluate the role of PLCγ1 in angiogenesis in vivo using chorioallantoic membrane (CAM) model. Methods:9 days old fertilized chicken eggs were used in the CAM assay. Baseline vessel formation was photographed in 45 CAMs by using S6D microscope with Leica DC 300F camera, and IM50 system. U–73122 (40 µM) a potent PLCγ1 inhibitor was placed on 26 CAMs and control (DMSO with DMEM ) was placed on 19 CAMs. These CAM were photographed 24 hours after incubation. The vascular patterns and density were analyzed using the digital Kodak ID 3.5 image analysis system. The difference (delta) between the baseline and the 24 hours after treatment or control was measured for each CAM. The difference (delta) between the baselines in the treatment group and control group was also measured for each CAM. The statistical significance between two groups was evaluated using t–test for independent samples on the two sample calculator Results:The mean of the change in measurement 24 hours after incubation in the control group was 43, and mean of the change in measurement 24 hours after incubation in the treatment group was –17, this was statistically significant with a p value of 0.00039. The mean of the baseline measurements in the treatment group was 94 and the mean of the baseline measurements in the control group was 64, these two groups were not statistically significant (p–value of 0.122). This data shows that the vascular density was significantly higher in the control group as compared to the treated group. Conclusions: The data shows that inhibition of PLCγ1 reduces the growth of blood vessel in an in vivo model of angiogenesis, corraborating the previous results on cell culture system. Thus targeting PLCγ1 offers a novel therapeutic venue for treatment of ocular neovascularization. Based on these results we plan to develop reagents and test their efficacy to inhibit angiogenesis.
Keywords: retinal neovascularization • proliferation