Browsing by Subject "Podoplanin"

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    Absence of lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Siggel, Robert; Schroedl, Falk; Dietlein, Thomas; Koch, Konrad R.; Platzl, Christian; Kaser-Eichberger, Alexandra; Cursiefen, Claus; Heindl, Ludwig M.
    Purpose. To evaluate the presence and appearance of blood and lymphatic vessels in nonfunctioning bleb capsules of glaucoma drainage devices (GDD). Materials and methods. Non-functioning (n=14) GDD-bleb capsules of 12 patients were analyzed by immunohistochemistry for blood vessels (CD31, vascular endothelium), lymphatic vessels (lymphatic vessel endothelial hyaluronan receptor-1 [LYVE-1] and podoplanin) and macrophages (CD68). Results. CD31+++ blood vessels and CD68+ macrophages were detected in the outer layer of all specimens. LYVE-1 immunoreactivity was registered in single non-endothelial cells in 8 out of 14 (57%) bleb capsule specimens. Podoplanin-immunoreactivity was detected in all cases, located in cells and profiles of the collagen tissue network of the outer and/or the inner capsule layer. However, a colocalization of LYVE-1 and podoplanin as evidence for lymphatic vessels was not detected. Conclusions. We demonstrate the presence of bloodvessels but absence of lymphatic vessels in nonfunctioning bleb capsules after GDD-implantation. While the absence of lymphatic vessels might indicate a possible reason for drainage device failure, this needs to be confirmed in upcoming studies, including animal experiments.
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    Elevated blood/lymphatic vessel ratio in pterygium and its relationship with vascular endothelial growth factor (VEGF) distribution
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Martín López, Javier; Pérez Rico, Consuelo; García Honduvilla, Natalio; Buján, Julia; Pascual, Gemma
    Introduction. Pterygium is a conjunctival fibrovascular tissue growth on the cornea. The pathogenesis of pterygium involves several factors such as the presence of active angiogenic factors. Expansion of the lymphatic microvasculature has also been hypothesized. This study examines the activity of the angiogenic/lymphangiogenic factor VEGF and the expression of vascular and lymphatic endothelial proteins in pterygia and normal conjunctival tissues. Materials and methods. Primary grade 2 pterygium (n=20) and normal conjunctiva (n=20) biopsies were obtained during surgery after written informed consent. mRNA expression for CD31, podoplanin, and VEGF (isoforms VEGF-A and VEGF-165) were determined by qRT-PCR. Tissue samples were also processed for immunohistochemical techniques to examine the lymphatic and vascular endothelium (anti-D2-40, antiCD31 respectively) and VEGF-A and VEGF-C levels and distribution. Results. VEGF-A gene expression levels failed to differ between the healthy and pterygium tissues. However, expression of its more angiogenic isoform, VEGF-165, was significantly higher in the pterygia. Immunohistochemistry revealed the greater presence of VEGF-A, compared to VEGF-C, in pterygium than conjunctiva, both in blood vessels and extracellular matrix. In addition, pterygia showed higher expression levels of the endothelial junction protein CD31. Lymphatic marker D2-40 expression was slightly augmented in this pathological tissue. The ratio between blood and lymphatic vessel counts was 1.05 in the normal conjunctiva and 3-fold this value in pterygium. Conclusion. In pterygium, while both lymphangiogenesis and angiogenesis take place, the formation of new blood vessels is the most relevant event, correlating with the increased expression of vascular endothelial CD31 and an elevated blood/lymphatic vessel ratio. The presence of high levels of VEGF-A in both vessel networks and extracellular matrix in human pterygium tissue may have a major impact on angiogenesis in this pathological tissue