http://repub.eur.nl/res/aut/8143/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/28311/ 2010-01-01T00:00:00Z In a previous study using state-of-the-art proteomic techniques, we identified colligin 2 (HSP47) as a glioma blood vessel-specific protein. In the present study we precisely localized the expression of colligin 2 in the blood vessels of diffusely infiltrating gliomas and relate the expression to the distinct cellular components of the vessels by using multiple immunolabeling and confocal microscopy. We grouped the glioma blood vessels into morphological categories ranging from normal looking capillaries to vessels with hypertrophic and sclerotic changes. The expression patterns of various markers of endothelial and pericytic differentiation were correlated with the position of the cells in the vessels and the expression of colligin 2. We found that colligin 2 is expressed in all categories of glioma blood vessels in cells with endothelial and pericytic lineage. Expression of colligin 2 was also found in cells scattered around blood vessels and in few glial fibrillary acidic protein-positive cells within the blood vessels. There is overlap in the expression of colligin 2 and the collagens type I and IV for which colligin 2 is a chaperon. We conclude that colligin 2 is expressed in all cellular components of glioma blood vessels and may serve as a general marker for active angiogenesis. http://repub.eur.nl/res/pub/27086/ 2009-02-01T00:00:00Z Aims: We explored the in vivo effects of knockdown of caldesmon on vascular development in zebrafish. Methods and results: We investigated the effects of caldesmon knockdown on the vascular development in a zebrafish model with special attention for the trunk and head vessels including the aortic arches. We examined the developing fishes at various time points. The vascular abnormalities observed in the caldesmon morphants were morphologically and functionally characterized in detail in fixed and living embryos. The knockdown of caldesmon caused serious defects in vasculogenesis and angiogenesis in zebrafish morphants, and the vascular integrity and blood circulation were concomitantly impaired. Conclusion: The data provide the first functional assessment of the role of caldesmon in vascular development in vivo, indicating that this molecule plays a crucial role in vasculogenesis and angiogenesis in vivo. Interfering with caldesmon opens new therapeutic avenues for anti-angiogenesis in cancer and ischaemic cardiovascular disease. http://repub.eur.nl/res/pub/10349/ 2004-01-01T00:00:00Z Caldesmon is a cytoskeleton-associated protein which has not yet been related to neoplastic angiogenesis. In this study we investigated the expression of the caldesmon gene (CALD1) splicing variants and the protein expression level in glioma microvessels versus normal brain microvasculature. To exclude sources of splice variant expression from non-vascular components all possible cellular components present in control and glioma samples were pre-screened by laser-capture microdissection followed by RT-PCR before the cohort study. We discovered differential expression of the splicing variants of CALD1 in the tumor microvessels in contrast to normal brain microvasculature. Missplicing of exons 1, 1 + 4, and 1' + 4 of the gene is exclusively found in glioma microvessels. To exclude the possibility that this missplicing results from splice-site mutations, mutation scanning was performed by a coupled in vitro transcription/translation assay (IVTT). No premature stop mutations were traced by the IVTT. The transcriptional changes consequently resulted in up-regulation at the protein expression level. The up-regulated expression of caldesmon was coincident with the down-regulated expression of tight junction proteins (occludin and ZO-1). The results support the notion that missplicing of the CALD1 gene in glioma microvasculature is an independent epigenetic event regulated at the transcriptional level. The event coexists with tight junction (TJ) breakdown of the endothelial cells in glioma microvasculature. The data reveal a novel mechanism contributing to dysfunctionality of glioma neovascularization. http://repub.eur.nl/res/pub/8845/ 1998-01-01T00:00:00Z BACKGROUND/AIMS: Earlier studies on intraocular tissue have demonstrated that T lymphocytes play a major role in the pathogenesis of uveitis. Adhesion molecules are immunoregulatory molecules for the interaction between T lymphocytes and vascular endothelium and they play an important role in the recruitment of specific T lymphocytes from the circulation into inflamed tissue. In uveitis an increased expression of some of these adhesion molecules may be expected. METHODS: The presence of adhesion molecules was investigated in iris biopsy specimens from 11 patients with uveitis and eight controls (patients with primary open angle glaucoma) immunohistochemically with a panel of monoclonal antibodies: LECAM (CD 62L), ICAM-1 (CD 54), LFA-1 (CD 11a/18), VCAM-1 (CD 106), VLA-4 (CD 49d), and HECA-452, a marker for high endothelial venules. RESULTS: Positive staining for ICAM-1, LFA-1 and VCAM-1 was found in the iris in a significantly higher number of uveitis patients than in controls. The remaining adhesion molecules were also found in a higher number of uveitis patients than in controls, but this difference did not reach statistical significance. CONCLUSION: An increased expression of adhesion molecules was found in the iris of patients with uveitis, indicating an immunoregulatory function for adhesion molecules in the pathogenesis of uveitis.