Mechanisms of retinal angiogenesis

以前我们已经证明Src-PLD 1-PKCγ-cPLA 2信号通路参与视网膜神经元的调节， 新生血管形成我们的研究还表明，Pak 1-cofilin信号轴的激活是 视网膜新生血管形成所必需的。此外，我们已经表明，除了VEGFA，VEGFC通过CREB- DLL 4-NOTCH 1信号通路介导的激活在HRMVEC的增强中起重要作用 在体外细胞培养模型和视网膜中的迁移、增殖、发芽和管形成 OIR模型中的体内新血管形成。在这些研究过程中，我们发现VEGFA和 低氧刺激PKCθ非常强烈，其水平的耗尽完全阻断了迁移和发芽 HRMVEC响应VEGFA的能力。我们还观察到VEGFA和缺氧都诱导了 Flt 4的表达非常强烈，这种反应需要PKCθ介导的JunB诱导。此外，双方 VEGFA和缺氧触发了CDC 6表达的诱导，CDC 6是复制前的调节成分。 复合物（前RC）并参与将迷你染色体维持蛋白（MCM 2 -7）加载到 DNA，它在复制中起着限速作用。此外，下调CDC 6水平完全 消除VEGF诱导的DNA合成。基于这些新发现，我们提出PKCθ通过 增强EC迁移和出芽以及CDC 6通过增强EC增殖在 调节视网膜新生血管。为了验证这一核心假设，我们将讨论以下四个具体问题。 目标。目标1。探讨PKCθ介导缺氧诱导的视网膜新生血管形成。目标二。到 检验JunB介导缺氧诱导的视网膜新生血管形成的假设。目标3。测试 假设PKCθ-JunB信号轴靶向Flt 4诱导介导视网膜新生血管形成。目标4。 为了验证CDC 6在视网膜新生血管形成中起重要作用的假设。的结果 提出的实验可能提供新的信息方面的分子机制， 病理性视网膜新生血管形成，这可能导致新的治疗化合物的开发 对抗这种眼病

Previously we have demonstrated that Src-PLD1-PKCγ-cPLA2 signaling is involved in the modulation of retinal neovascularization. Our studies have also demonstrated that activation of Pak1-cofilin signaling axis is required for retinal neovascularization. Furthermore, we have shown that besides VEGFA, VEGFC via CREB- mediated activation of DLL4-NOTCH1 signaling plays an important role in the enhancement of HRMVEC migration, proliferation, sprouting and tube formation in vitro in a cell culture model and retinal neovascularization in vivo in an OIR model. During the course of these studies, we found that both VEGFA and hypoxia stimulate PKCθ very robustly and depletion of its levels completely blocks the migrating and sprouting capacity of HRMVECs in response to VEGFA. We have also observed that both VEGFA and hypoxia induce Flt4 expression profoundly and this response requires PKCθ-mediated JunB induction. Furthermore, both VEGFA and hypoxia triggered the induction of expression of CDC6, a regulatory component of pre-replication complex (pre-RC) and involved in loading the mini chromosome maintenance proteins (MCM2-7) onto the DNA, which plays a rate-limiting step in replication. In addition, down regulation of CDC6 levels completely abolished VEGFA-induced DNA synthesis. Based on these novel discoveries, we propose that PKCθ via enhancing EC migration and sprouting and CDC6 via enhancing EC proliferation play an integral role in the modulation retinal neovascularization. To test this central hypothesis, we will address the following four specific aims. Aim 1. To test the hypothesis that PKCθ mediates hypoxia-induced retinal neovascularization. Aim 2. To test the hypothesis that JunB mediates hypoxia-induced retinal neovascularization. Aim 3. To test the hypothesis that PKCθ-JunB signaling axis targets Flt4 induction in mediating retinal neovascularization. Aim 4. To test the hypothesis that CDC6 plays an essential role in retinal neovascularization. The results of the proposed experiments may provide novel information in regard to the molecular mechanisms underling pathological retinal neovascularization, which could lead to the development of new therapeutic compounds against this ocular disease.