Purpose

Mast cells, historically known for their effector function in the induction of allergic diseases, reside in all vascularized tissues of the body in particular proximity to blood and lymphatic vessels. As neighboring sentinel cells to blood vessels, mast cells have been associated with angiogenesis. Here we assess the direct contribution of mast cells to neovascularization at the ocular surface.

Methods

Corneal neovascularization was induced by placing a single figure-of-eight intrastromal suture 1 mm from the limbus in mast cell-deficient (cKit^W-sh), C57BL/6, and Balb/c mice. Corneas were harvested at 6 h post-suture to quantify cKit⁺FcεR1⁺ mast cells using flow cytometry and tear wash was collected within 6 h to measure β-hexosaminidase and tryptase. Neovascularization was assessed using slit-lamp biomicroscope and immunohistochemistry analysis of corneas harvested on day 4 post-suture. To investigate the effects of mast cells on blood vessel growth, mast cells were co-cultured with vascular endothelial cells (VECs), and tube formation and proliferation of VECs were measured. 2% cromolyn was administered locally to inhibit mast cell activation in vivo.

Results

Placement of corneal suture activates ocular surface mast cells, which infiltrate into the cornea adjacent to new vessels. Mast cell-deficient mice develop significantly fewer new vessels following suture placement. Mast cells directly promote VEC proliferation and tube formation, partly through secreting high levels of VEGF-A. Pharmacological inhibition of mast cell activation results in significantly less corneal neovascularization.

Conclusion

Our data demonstrate that ocular surface mast cells are critical to corneal neovascularization, suggesting mast cells as a potential therapeutic target in the treatment of corneal neovascularization.

中文翻译：

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眼表肥大细胞的激活促进角膜新生血管形成。

目的

肥大细胞，历史上以其在过敏性疾病诱导中的效应功能而闻名，存在于身体的所有血管化组织中，特别是靠近血液和淋巴管的组织中。作为血管的邻近前哨细胞，肥大细胞与血管生成有关。在这里，我们评估了肥大细胞对眼表新血管形成的直接贡献。

方法

通过在肥大细胞缺陷型 (cKit ^W-sh )、C57BL/6 和 Balb/c 小鼠的角膜缘 1 mm 处放置一条 8 字形基质内缝合线来诱导角膜新生血管形成。在缝合后 6 小时收获角膜以使用流式细胞术定量 cKit ⁺ FcεR1 ⁺肥大细胞，并在 6 小时内收集泪液以测量 β-氨基己糖苷酶和类胰蛋白酶。使用裂隙灯生物显微镜和缝合后第 4 天收获的角膜的免疫组织化学分析评估新生血管形成。为了研究肥大细胞对血管生长的影响，肥大细胞与血管内皮细胞 (VECs) 共培养，并测量了血管内皮细胞的管形成和增殖。局部施用2%色甘酸以抑制肥大细胞活化体内。

结果

角膜缝合线的放置激活了眼表肥大细胞，这些细胞浸润到与新血管相邻的角膜中。肥大细胞缺陷小鼠在缝合后形成的新血管明显减少。肥大细胞直接促进 VEC 增殖和管形成，部分是通过分泌高水平的 VEGF-A。肥大细胞活化的药理学抑制导致角膜新生血管形成显着减少。

结论

我们的数据表明，眼表肥大细胞对角膜新生血管形成至关重要，这表明肥大细胞是治疗角膜新生血管的潜在治疗靶点。