Intercapillary bridging cells: immunocytochemical characteristics of cells that connect blood vessels in the retina

Autor: Andreia Valença, Alfonso Rodríguez-Baeza, Ana Carretero, Marc Navarro, Cristina Llombart, M Lopez-Luppo, Jesús Ruberte, L Mendes-Jorge, Simón Méndez-Ferrer, Víctor Nacher, David Ramos
Rok vydání: 2011
Předmět:
Adult
Pathology
medicine.medical_specialty
Green Fluorescent Proteins
Connexin
Antigens
CD34
Mice
Transgenic
Nerve Tissue Proteins
Cell Communication
Retinal Neovascularization
Filamentous actin
Immunophenotyping
Nestin
Receptor
Platelet-Derived Growth Factor beta
Cellular and Molecular Neuroscience
Immunolabeling
Mice
Intermediate Filament Proteins
Laminin
Polysaccharides
medicine
Animals
Humans
Antigens
skin and connective tissue diseases
Fluorescent Antibody Technique
Indirect
Basement membrane
Aged
80 and over
Retina
biology
Retinal Vessels
Glaucoma
Sensory Systems
Capillaries
Mice
Inbred C57BL
Platelet Endothelial Cell Adhesion Molecule-1
Ophthalmology
Disease Models
Animal
medicine.anatomical_structure
biology.protein
Cytochemistry
Desmin
Proteoglycans
Endothelium
Vascular
Pericytes
Biomarkers
Zdroj: Experimental eye research. 98
ISSN: 1096-0007
Popis: Intervascular bridges are fibrous strands that connect neighboring capillaries. These strands present associated cells, intervascular bridging cells (IBCs), whose nature and functional significance remains controversial. The aim of this study was to characterize the immunophenotype of IBCs, and contribute to understand their mechanical and intercellular communication properties in the retina. Quantification and retinal distribution of IBCs were also determined. For this purpose, C57BL/6N and nestin-GFP transgenic mice, as well as human retinas, were used. Whole-mount retinas were studied by means of immunohistochemistry and cytochemistry, and isolation of retinal vasculature was achieved by trypsin/pepsin digest technique. PAS reaction and the immunolabeling with anti-collagen IV and laminin antibodies revealed that IBCs were completely surrounded by a basement membrane, connecting two or more neighboring capillaries. IBCs were scarce and their number decreased with age. They were preferentially localized in the deep vascular plexus. In a murine model of experimental glaucoma, methylcellulose injected eyes showed retinal neovascularization and increased number of IBCs in the deep vascular plexus. IBCs were marked with anti-NG2, anti-PDGFR-β and anti-CD34 antibodies, and with tomato lectin, and were negative for PECAM-1. IBCs expressed nestin and filamentous actin, but desmin and α-smooth muscle actin were not detected. Moreover, these cells expressed the gap junction protein connexin 43. These results showed that IBCs had a pericytic nature since they expressed NG2 and the receptor for PDGF-B, and they were negative for PECAM-1. However, they were marked with CD34 and the tomato lectin, suggesting that they constitute a special subtype of pericytes, sharing characteristics with endothelial cells. IBCs presumably present mechanical functions due to the presence of filamentous actin. Connexin 43 was found in IBCs, suggesting that these cells allow intercellular communication between adjacent capillaries. This may represent an advantage for vasomotor tone integration and coordination in blood vessels without innervation, such as those of the retina.
Databáze: OpenAIRE
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