PI3Kδ介导Akt磷酸化促进PDR患者视网膜新生血管生成的机制研究

The main pathology of proliferative diabetic retinopathy is retina angiogenesis, and the PI3K play an important role in the process of VEGF induced neovascularization. Our previous data show that the expression of PI3Kδ in retina endothelial cells is higher than other cells. A small molecular compounds, Idelalisib, specific PI3Kδ inhibitor prevent VEGF induced Akt phosphorylation, and it also block the ability of choroid explant and choroid angiogenesis, however it is unclear that the effect and mechanism of Idelalisib in blocking retinal angiogenesis. This project study the role of PI3Kδ in human retina endothelial cells, which can prevent retina angiogenesis using pharmacology and molecular approach, some technology will engage such as co-precipitation and base editing. We will prove that PI3Kδ can direct binding to VEGFR2, and it can inhibit the proliferation of endothelial cell though some specific domain. These results will reveal the mechanism of PI3Kδ in anti-angiogenesis and provide the strong foundation of the factor that Idelalisib become one alternative therapy in retina angiogenesis.

视网膜新生血管是增殖性糖尿病视网膜病的主要病理改变，PI3K介导的VEGF在新生血管的形成过程中起重要作用。我们前期研究发现：视网膜血管内皮细胞中PI3Kδ表达较其他细胞多。小分子化合物Idelalisib能通过特异性抑制PI3Kδ降低VEGF诱导p-Akt增加，并且Idelalisib能够抑制脉络膜细胞出芽与脉络膜新生血管，然而是否能抑制视网膜新生血管的形成以及其机制不清。为此，本课题拟通过药物学及分子生物学手段分析敲除视网膜血管内皮细胞PI3Kδ在视网膜新生血管发生中的作用。进一步用免疫共沉淀和Base editing等技术，来证明PI3Kδ是否能够与VEGFR2结合，以及结合VEGFR2哪个区域来影响血管内皮细胞增殖的机制。研究结果不仅有助于揭示Idelalisib抗新生血管的机制，并将为Idelalisib成为抑制视网膜新生血管的治疗药物提供理论基础和实验依据。

视网膜新生血管是增殖性糖尿病视网膜病的主要病理改变，PI3K介导的VEGF在新生血管的 形成过程中起重要作用。我们发现视网膜血管内皮细胞在低氧高糖环境下，诱导细胞内脂质磷酸酶PI3Kd增高。PI3Ka与PI3Kb广泛表达各组织细胞中，而PI3Kd仅在白细胞中高表达，我们首次发现视网膜血管内皮细胞中PI3Kd表达相比于其他组织内皮细胞表达高，特别是在低氧高糖环境下表达显著增多。用药物抑制HRECs中PI3Kd的活性能明显抑制VEGF，bFGF, EGF以及玻璃体诱导的增殖和迁移能力，体内实验也进一步证明特异性小分子抑制剂idelalisib通过PI3Kd降低氧诱导的视网膜新生血管 (oxygen induced retinopathy, OIR)模型中玻璃体的VEGFA及视网膜病理新新生血管。通过单细胞测序发现在OIR模型中视网膜中小胶质细胞细胞群增多我们进一步探讨小胶质细胞增加如何参与视网膜新生血管形成的机制。