Tissue and cellular characterisation of nucleolin in a murine model of corneal angiogenesis.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: NCL mobilisation outside the nucleus during angiogenesis could have a possible role as a proangiogenic molecule in the corneal tissue.

Inmunolocalización del complejo polisacárido-proteína en ultraestructuras de la fase micelial y levaduriforme de Histoplasma capsulatum / Immunolocalization of the polysaccharide-protein complex (PPCD-Histo) in the Histoplasma capsulatum mycelium and yeast phase ultrastructures

Introducción: El empleo de un antígeno parcialmente purificado denominado complejo polisacárido-proteína desproinizado de Histoplasma capsulatum (CPPD-Histo), utilizado para discriminar la histoplasmosis de diversas micosis pulmonares y otras enfermedades respiratorias en métodos inmunodiagnósticos de alta sensibilidad, ha sido motivo de estudio desde hace años por nuestro grupo de investigación: Objetivo: En este trabajo se planteó conocer la ubicación celular preferencial del antígeno CPPD-Histo, en las diferentes formas y estructuras de las fases micelial y levaduriforme del hongo. Material y métodos: El estudio se desarrolló mediante inmunolocalización con marcaje de oro coloidal para microscopia electrónica, usando anticuerpos primarios CPPD-Histo específicos. Resultados y discusión: La localización en microscopia electrónica mostró mayor concentración del CPPD-Histo en las zonas de mayor grosor de la capa externa de la pared celular de las proyecciones digitiformes de macroconidios, poco marcaje en pared celular de hifas, y una distribución dispersa de la marca en las levaduras. Conclusión: La pared celular de los macroconidios de la fase micelial del hongo es la estructura fúngica con mayor concentración del antígeno CPPD-Histo