Lin Ying-Yu, Warren Emily, Macklin Bria L, Ramirez Lucas, Gerecht Sharon
Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States.
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, United States.
Invest Ophthalmol Vis Sci. 2025 Sep 2;66(12):45. doi: 10.1167/iovs.66.12.45.
Endothelial-pericyte interaction disruption causes vascular dropout and pathological angiogenesis, severely impacting visual function in ocular microvascular diseases. This study examines VEGF receptor 2 (VEGFR2) signaling in endothelial-pericyte interactions, highlighting VEGFR2 as a potential therapeutic target for promoting pericyte coverage and decreasing vascular leakage in diseased retinas.
Cell-cell interactions with VEGFR2 signaling were assessed using isogenic endothelial cells and pericytes from induced pluripotent stem cells. We investigated changes in VEGFR2 signaling resulting from endothelial-pericyte interactions using quantitative Reverse Transcription PCR, western blot analysis, immunofluorescence staining, migration assays, permeability assays, transendothelial electrical resistance measurements, flow cytometry, and three-dimensional collagen gel vascular networks. We validated VEGFR2 as a therapeutic target via intravitreal injection in the oxygen-induced retinopathy mouse model. Treatment effects were evaluated using western blot analysis, immunofluorescence staining, and an FITC-dextran permeability assay to assess protein expression, pericyte recruitment, and retinal vascular function in response to VEGFR2 modulation.
We demonstrate that direct endothelial-pericyte contact, mediated by N-cadherin, downregulates phosphorylated VEGFR2 in endothelial cells, thereby enhancing pericyte migration and promoting endothelial cell barrier function. Intravitreal injection of a VEGFR2 inhibitor in mouse models of the developing retina and oxygen-induced retinopathy increased pericyte recruitment and decreased vascular leakage. The VEGFR2 inhibitor further rescued ischemic retinopathy by enhancing vascularization and tissue growth.
Our findings uncover a novel mechanism by which VEGFR2 signaling is regulated through endothelial-pericyte interactions, promoting pericyte migration and strengthening endothelial barrier function. These results suggest a pathway that could be harnessed to support the growth of functional and mature microvasculature in ocular microvascular diseases and tissue regeneration overall.
内皮细胞与周细胞相互作用的破坏会导致血管缺失和病理性血管生成，严重影响眼部微血管疾病的视觉功能。本研究检测了内皮细胞与周细胞相互作用中的血管内皮生长因子受体2（VEGFR2）信号传导，强调VEGFR2作为促进周细胞覆盖和减少病变视网膜血管渗漏的潜在治疗靶点。
使用来自诱导多能干细胞的同基因内皮细胞和周细胞评估与VEGFR2信号传导相关的细胞间相互作用。我们通过定量逆转录聚合酶链反应、蛋白质印迹分析、免疫荧光染色、迁移试验、通透性试验、跨内皮电阻测量、流式细胞术和三维胶原凝胶血管网络，研究了内皮细胞与周细胞相互作用引起的VEGFR2信号传导变化。我们通过在氧诱导性视网膜病变小鼠模型中玻璃体注射来验证VEGFR2作为治疗靶点。使用蛋白质印迹分析、免疫荧光染色和异硫氰酸荧光素-葡聚糖通透性试验评估VEGFR2调节对蛋白质表达、周细胞募集和视网膜血管功能的治疗效果。
我们证明，由N-钙黏蛋白介导的内皮细胞与周细胞的直接接触可下调内皮细胞中磷酸化的VEGFR2，从而增强周细胞迁移并促进内皮细胞屏障功能。在发育中的视网膜和氧诱导性视网膜病变小鼠模型中玻璃体注射VEGFR2抑制剂可增加周细胞募集并减少血管渗漏。VEGFR2抑制剂通过增强血管生成和组织生长进一步挽救了缺血性视网膜病变。
我们的研究结果揭示了一种新机制，即通过内皮细胞与周细胞的相互作用来调节VEGFR2信号传导，促进周细胞迁移并增强内皮屏障功能。这些结果提示了一条可用于支持眼部微血管疾病中功能性和成熟微血管生长以及整体组织再生的途径。
