Quiroz-Mercado Joaquín, Ramírez-Velázquez Norma, Partido Graciela, Zenteno Edgar, Chávez Raúl, Agundis-Mata Concepción, Jiménez-Martínez Maria Carmen, Garfias Yonathan
Research Unit, Institute of Ophthalmology Conde de Valenciana Foundation, Chimalpopoca 14, 06800, Mexico City, Mexico.
Faculty of Veterinary Medicine and Animal Husbandry, Universidad Nacional Autónoma de México, Avenida Universidad 3000, 04510, Mexico City, Mexico.
Graefes Arch Clin Exp Ophthalmol. 2016 Sep;254(9):1753-63. doi: 10.1007/s00417-016-3409-8. Epub 2016 Jun 16.
Corneal neovascularisation (CNV), with consequent loss of transparency, is due to an imbalance of proangiogenic factors. Cell-surface nucleolin (NCL) has been associated with neo-angiogenesis. There are studies identifying NCL translocation from nucleus to the cell surface, which is essential for endothelial cell proliferation. To find the possible role of NCL in the generation of corneal neovessels, the aim of this study is to characterise the NCL presence and cell-localisation in non-injured corneas, as well as to describe the changes in NCL cell and tissue localisation in CNV, and to analyse the effect of bevacizumab on NCL cellular and tissular distribution.
Suture-induced CNV was performed in mice. The corneal tissues were obtained and the histological and co-immunofluorescence assays were performed using different proteins, such as CD31, cadherin and isolectin B4. To determine the possible role of VEGF in NCL presence and localisation in our CNV model, bevacizumab was concomitantly used.
Nucleolin was principally observed in the nucleus of the basal epithelial cells of normal corneas. Interestingly, angiogenesis-induced changes were observed in the localisation of NCL, not only in tissue but also at the cellular level where NCL was extranuclear in epithelial cells, stromal cells and neovessels. In contrast, these changes were reverted when bevacizumab was used. Besides, NCL was able to stain only aberrant corneal neovessels in comparison with retinal vessels.
NCL mobilisation outside the nucleus during angiogenesis could have a possible role as a proangiogenic molecule in the corneal tissue.
角膜新生血管形成（CNV）会导致透明度丧失，这是由促血管生成因子失衡所致。细胞表面核仁素（NCL）与新生血管形成有关。有研究发现NCL从细胞核易位至细胞表面，这对内皮细胞增殖至关重要。为探究NCL在角膜新生血管生成中的可能作用，本研究旨在明确NCL在未受损角膜中的存在情况和细胞定位，描述NCL在CNV中的细胞及组织定位变化，并分析贝伐单抗对NCL细胞和组织分布的影响。
在小鼠中进行缝线诱导的CNV。获取角膜组织，并使用不同蛋白质（如CD31、钙黏蛋白和异凝集素B4）进行组织学和共免疫荧光检测。为确定VEGF在我们的CNV模型中对NCL存在和定位的可能作用，同时使用了贝伐单抗。
核仁素主要在正常角膜基底上皮细胞的细胞核中观察到。有趣的是，不仅在组织水平，而且在细胞水平均观察到NCL定位发生了血管生成诱导的变化，其中上皮细胞、基质细胞和新生血管中的NCL位于细胞核外。相比之下，使用贝伐单抗后这些变化得以逆转。此外，与视网膜血管相比，NCL仅能使异常的角膜新生血管染色。
血管生成过程中NCL在细胞核外的移动可能在角膜组织中作为促血管生成分子发挥作用。
