Search results for "Endothelial stem cell"
showing 10 items of 282 documents
Tailoring Novel PTFE Surface Properties: Promoting Cell Adhesion and Antifouling Properties via a Wet Chemical Approach
2016
Many biomaterials used for tissue engineering applications lack cell-adhesiveness and, in addition, are prone to nonspecific adsorption of proteins. This is especially important for blood-contacting devices such as vascular grafts and valves where appropriate surface properties should inhibit the initial attachment of platelets and promote endothelial cell colonization. As a consequence, the long-term outcome of the implants would be improved and the need for anticoagulation therapy could be reduced or even abolished. Polytetrafluoroethylene (PTFE), a frequently used polymer for various medical applications, was wet-chemically activated and subsequently modified by grafting the endothelial …
Platelet, Not Endothelial, P-Selectin Expression Contributes to Generation of Immunity in Cutaneous Contact Hypersensitivity
2010
Leukocyte extravasation is a prerequisite for host defense and autoimmunity alike. Detailed understanding of the tightly controlled and overlapping sequences of leukocyte extravasation might aid development of novel therapeutic strategies. Leukocyte extravasation is initiated by interaction of selectins with appropriate carbohydrate ligands. Lack of P-selectin expression leads to decreased contact hypersensitivity responses. Yet, it remains unclear if this is due to inhibition of leukocyte extravasation to the skin or due to interference with initial immune activation in lymph nodes. In line with previous data, we here report a decreased contact hypersensitivity response, induced by 2,4,-di…
Platelet-endothelial interaction in tumor angiogenesis and microcirculation
2003
Activated platelets release angiogenic growth factors and have therefore been proposed to contribute to tumor angiogenesis within a potentially prothrombotic tumor microcirculation. The aim of the study was to investigate interactions of platelets with the angiogenic microvascular endothelium of highly vascularized solid tumors during growth and in response to endothelial stimulation in comparison with normal subcutaneous tissue. Experiments were performed in the dorsal skinfold chamber preparation of C57BL/6J mice bearing the Lewis lung carcinoma (LLC-1) or methylcholanthrene-induced fibrosarcoma (BFS-1). Fluorescently labeled rolling and adherent platelets, red blood cell velocity, and ve…
Generation of human pulmonary microvascular endothelial cell lines.
2001
The limited lifespan of human microvascular endothelial cells in cell culture represents a major obstacle for the study of microvascular pathobiology. To date, no endothelial cell line is available that demonstrates all of the fundamental characteristics of microvascular endothelial cells. We have generated endothelial cell lines from human pulmonary microvascular endothelial cells (HPMEC) isolated from adult donors. HPMEC were cotransfected with a plasmid encoding the catalytic component of telomerase (hTERT) and a plasmid encoding the simian virus 40 (SV40) large T antigen. Cells transfected with either plasmid alone had an extended lifespan, but the cultures eventually entered crisis aft…
Tumorigenic conversion of endothelial cells.
2003
Tumors of endothelial origin develop rarely. Until now, only two angiosarcoma (AS)-derived endothelial cell lines have been be isolated, ISO-HAS and AS-M. Both AS-derived endothelial cell lines presented the typical endothelial characteristics, such as the expression of CD31 and von Willebrand factor, but differed from normal endothelial cells in a nuclear expression of p53, in a delayed angiogenic reaction, and a reduced expression of caveolin. In addition, differences in the expression of cytokines and cell adhesion molecules responsive to proinflammatory stimuli were observed. While AS-M showed an expression pattern similar to that of human umbilical vein endothelial cells (HUVEC), ISO-H…
Expression of endothelial cell adhesion molecules on heart valves: up-regulation in degeneration as well as acute endocarditis
2000
Inflammatory cytokines such as interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha), as well as shear stress, cause endothelial cells (ECs), to undergo not only functional alterations but also structural reorganizations, which contribute to vascular leakage. Like ECs of the human aorta, ECs on heart valves are exposed to extreme shear stress. However, while ECs expression of cell adhesion molecules (CAMs) in large vessels has been widely studied, it seems that there are no such studies on ECs of heart valves, although this knowledge might be important for our understanding of the aetiological aspects of local inflammatory responses. Using immunohistochemistry, this study charac…
Endothelial VEGFR-3 expression in colorectal carcinomas is associated with hematogenous metastasis
2009
Vascular endothelial growth factor receptor 3 (VEGFR-3) is a major inducer of lymphangiogenic signalling and seems to be involved also in angiogenesis. Since both processes are closely linked with tumor metastasis this study investigated the expression of VEGFR-3 in tumor-associated vessels in colorectal carcinomas and evaluated its relevance for lymphogenous and hematogenous metastasis. In a comparative study between microvascular endothelial cells isolated from the tumor (HCTEC) and the corresponding non-neoplastic tissue (HCMEC) from five patients with colorectal cancer VEGFR-3 expression was measured using a specific ELISA. The expression pattern was individually different, with cases s…
Heterogeneous expression of cell adhesion molecules by endothelial cells in ARDS
2002
ARDS (acute respiratory distress syndrome) can be associated with septic shock and multiple organ failure caused by an uncontrolled systemic inflammatory response to Gram-negative bacterial infection. While in animal models the key role of the endothelial adhesion molecules ICAM-1, E-selectin, and VCAM in ARDS has been extensively studied, there are scarcely any corresponding pathomorphological studies of human lung tissue. Hence, little is known about whether there is a comparable, or even heterogeneous, expression pattern of these molecules in the human pulmonary vasculature. This study was therefore undertaken to investigate the immunohistochemical expression of the constitutively expres…
Uterine glomeruloid hemangioma in a patient without POEMS syndrome.
2011
Cutaneous glomeruloid hemangioma is a hallmark of POEMS syndrome. These patients have elevated serum levels of vascular endothelial growth factor. The authors report an extracutaneous uterine glomeruloid hemangioma in an 82-year-old woman with a history of breast and endometrial carcinomas. Within the lumen of myometrial vessels, a lobular, glomeruloid proliferation of capillary-like CD31 and vascular endothelial growth factor receptor-1-positive endothelial cells was found. The capillary loops were lined by endothelial cells, most of them containing PAS-positive and immunoglobulin-positive eosinophilic hyaline globules (thanatosomes). This vascular proliferation was consistent with a glom…
The effect of human osteoblasts on proliferation and neo-vessel formation of human umbilical vein endothelial cells in a long-term 3D co-culture on p…
2008
Angiogenesis is a key element in early wound healing and is considered important for tissue regeneration and for directing inflammatory cells to the wound site. The improvement of vascularization by implementation of endothelial cells or angiogenic growth factors may represent a key solution for engineering bone constructs of large size. In this study, we describe a long-term culture environment that supports the survival, proliferation, and in vitro vasculogenesis of human umbilical vein endothelial cells (HUVEC). This condition can be achieved in a co-culture model of HUVEC and primary human osteoblasts (hOB) employing polyurethane scaffolds and platelet-rich plasma in a static microenvir…