Schepens Eye Research Institute, Department of Ophthalmology, Medical School, Boston, Massachusetts, USA.
Invest Ophthalmol Vis Sci. 2013 Jan 28;54(1):813-20. doi: 10.1167/iovs.11-8379.
To evaluate the regulatory cross-talk of the vascular and neural networks in the cornea.
b-FGF micropellets (80 ng) were implanted in the temporal side of the cornea of healthy C57Bl/6 mice. On day 7, blood vessels (hemangiogenesis) and nerves were observed by immunofluorescence staining of corneal flat mounts. The next group of mice underwent either trigeminal stereotactic electrolysis (TSE), or sham operation, to ablate the ophthalmic branch of the trigeminal nerve. Blood vessel growth was detected by immunohistochemistry for PECAM-1 (CD31) following surgery. In another set of mice following TSE or sham operation, corneas were harvested for ELISA (VEGFR3 and pigment epithelium-derived factor [PEDF]) and for quantitative RT-PCR (VEGFR3, PEDF, and CD45). PEDF, VEGFR3, beta-3 tubulin, CD45, CD11b, and F4/80 expression in the cornea were evaluated using immunostaining.
No nerves were detected in the areas subject to corneal neovascularization, whereas they persisted in the areas that were neovessel-free. Conversely, 7 days after denervation, significant angiogenesis was detected in the cornea, and this was associated with a significant decrease in VEGFR3 (57.5% reduction, P = 0.001) and PEDF protein expression (64% reduction, P < 0.001). Immunostaining also showed reduced expression of VEGFR3 in the corneal epithelial layer. Finally, an inflammatory cell infiltrate, including macrophages, was observed.
Our data suggest that sensory nerves and neovessels inhibit each other in the cornea. When vessel growth is stimulated, nerves disappear and, conversely, denervation induces angiogenesis. This phenomenon, here described in the eye, may have far-reaching implications in understanding angiogenesis.
评估角膜中血管和神经网络的调节串扰。
将 b-FGF 微球（80ng）植入健康 C57Bl/6 小鼠的角膜颞侧。第 7 天，通过角膜平片的免疫荧光染色观察血管（血管生成）和神经。下一组小鼠接受三叉神经立体定向电解（TSE）或假手术以切除三叉神经眼支。手术后通过 PECAM-1（CD31）的免疫组化检测血管生长。在另一组接受 TSE 或假手术的小鼠中，收获角膜进行 ELISA（VEGFR3 和色素上皮衍生因子[PEDF]）和定量 RT-PCR（VEGFR3、PEDF 和 CD45）。使用免疫染色评估角膜中 PEDF、VEGFR3、β-3 微管蛋白、CD45、CD11b 和 F4/80 的表达。
在受角膜新生血管影响的区域未检测到神经，而在无新生血管的区域仍存在神经。相反，在去神经后 7 天，角膜中检测到明显的血管生成，这与 VEGFR3（减少 57.5%，P=0.001）和 PEDF 蛋白表达（减少 64%，P<0.001）的显著降低相关。免疫染色还显示角膜上皮层中 VEGFR3 的表达减少。最后，观察到包括巨噬细胞在内的炎症细胞浸润。
我们的数据表明，感觉神经和新生血管在角膜中相互抑制。当血管生长受到刺激时，神经消失，相反，去神经会诱导血管生成。这种现象在眼睛中被描述，可能对理解血管生成具有深远的意义。
