Search results for "blas"
showing 10 items of 2217 documents
Hypoxia-stimulated expression of angiogenic growth factors in cervical cancer cells and cervical cancer-derived fibroblasts
2001
It is generally accepted that local growth of solid tumors and their ability to establish distant metastases are dependent on the formation of new blood vessels arising from preexisting ones (angiogenesis). The angiogenic response of the host is mediated by angiogenic molecules that are released from cancer and normal stroma cells, especially fibroblasts. The goal of the present study was to quantitatively compare the expression of the two most important angiogenic growth factors (VEGF, angiogenin) of cervical cancer cells (HeLa and Me-180) with that of cervical cancer-derived fibroblasts (from one tumor/patient) under defined normoxic and hypoxic conditions in vitro. The growth kinetics of…
High levels of HIF-2α highlight an immature neural crest-like neuroblastoma cell cohort located in a perivascular niche
2007
High HIF-2alpha protein levels in the sympathetic nervous system-derived childhood tumour neuroblastoma as well as immature phenotype correlate to unfavourable outcome. Here we show that a small subset of perivascularly located, strongly HIF-2alpha-positive tumour cells (MYCN amplified) lacks expression of differentiation markers, but expresses neural crest and early sympathetic progenitor marker genes such as Notch-1, HES-1, c-Kit, dHAND, and vimentin. HIF-2alpha- and CD68-positive tumour-associated macrophages were frequently found close to the immature and HIF-2alpha-positive neuroblastoma cells and as VEGF levels are high in the perivascular niche, we hypothesize that neuroblastoma neur…
Scaffold vascularization in vivo driven by primary human osteoblasts in concert with host inflammatory cells.
2011
Successful cell-based tissue engineering requires a rapid and thorough vascularization in order to ensure long-term implant survival and tissue integration. The vascularization of a scaffold is a complex process, and is modulated by the presence of transplanted cells, exogenous and endogenous signaling proteins, and the host tissue reaction, among other influencing factors. This paper presents evidence for the significance of pre-seeded osteoblasts for the in vivo vascularization of a biodegradable scaffold. Human osteoblasts, cultured on silk fibroin micronets in vitro, migrated throughout the interconnected pores of the scaffold and produced extensive bone matrix. When these constructs we…
Comparative study assessing effects of sonic hedgehog and VEGF in a human co-culture model for bone vascularisation strategies.
2011
The morphogen sonic hedgehog (Shh) seems to mediate adult repair processes in bone regeneration and vascularisation. In this study we investigated the effects of Shh on co-cultures consisting of human primary osteoblasts and outgrowth endothelial cells in terms of angiogenic activation and vessel maturation in comparison to the treatment with the commonly used proangiogenic factor, VEGF. Both, stimulation with VEGF or Shh, leads to an increase in the formation of microvessel-like structures compared to untreated controls. In contrast to VEGF, proangiogenic effects by Shh could already be observed after 24 h of treatment. Nevertheless, after 14 days the angiogenic activity of OEC was compara…
Sonic hedgehog promotes angiogenesis and osteogenesis in a coculture system consisting of primary osteoblasts and outgrowth endothelial cells.
2009
A number of previous studies documented the angiogenic potential of outgrowth endothelial cells in vitro and in vivo and provided evidence that therapeutic success could depend on coculture or coimplantation strategies. Thus, deeper insight into the molecular mechanisms underlying this pro-angiogenic effect of cocultures might provide new translational options for tissue engineering and regenerative medicine. One promising signaling pathway in bone repair involved in neoangiogenesis and bone formation is the sonic hedgehog (Shh) pathway. In this article, we focus on the effect of Shh on the formation of microvessel-like structures and osteoblastic differentiation in cocultures of primary os…
Priming with a combination of proangiogenic growth factors improves wound healing in normoglycemic mice
2011
Growth factors and/or angiogenic factors are supposed to improve wound healing. The aim of our study was to evaluate the effects of subcutaneous pretreatment with combinatory proangiogenic factors on wound closure, mechan - ical properties, vessel density and morphology. Twenty-eight Balb/c mice were divided equally into two groups. A mixture of VEGF (35.0 µg), bFGF (2.5 µg) and P dGF (3.5 µg) was administered subcutaneously 3, 5 and 7 days to 14 mice before full thickness skin punch biopsy wounding, whereas 14 control animals received three injections of 0.2 ml saline solution. Wound sizes were assessed daily and the repaired tissues were harvested 7 days after complete wound closure. Comp…
Protein kinase C promotes angiogenic activity of human endothelial cells via induction of vascular endothelial growth factor
2008
Aims Protein kinase C (PKC) plays an important role in the regulation of angiogenesis. However, downstream targets of PKC in endothelial cells are poorly defined. Methods and results mRNA expression of vascular endothelial growth factor (VEGF) was analysed by quantitative real-time RT-PCR in human umbilical vein endothelial cells (HUVEC) and HUVEC-derived EA.hy 926 cells. siRNA was used to knockdown PKC isoforms and VEGF. Matrigel tube formation assay was used to analyse the angiogenic activity of endothelial cells. Phorbol-12-myristate-13-acetate (PMA) enhanced the ability of HUVEC to organize into tubular networks when plated on Matrigel, a phenomenon that could be prevented by PKC inhibi…
Priming with a Combination of Proangiogenic Growth Factors Enhances Wound Healing in Streptozotocin-Induced Diabetes in Mice
2010
<i>Background:</i> Numerous proangiogenic growth factors have been shown to improve impaired wound healing. This study evaluated the effects of subcutaneous pretreatment with a combination of proangiogenic growth factors on wound closure, mechanical properties, vessel density, and morphology. <i>Methods:</i> Thirty-six Balb/c mice with streptozotocin-induced diabetes were divided into 3 groups. A mixture of VEGF (35.0 µg), bFGF (2.5 µg), and PDGF (3.5 µg) was administered subcutaneously 3, 5, and 7 days prior to wounding in the first group, whereas the second group received three doses of 3.5 µg PDGF. Wound sizes were assessed daily and the repaired tissues were harv…
Heart infarct in NOD-SCID mice: therapeutic vasculogenesis by transplantation of human CD34+ cells and low dose CD34+KDR+ cells
2004
Hematopoietic (Hem) and endothelial (End) lineages derive from a common progenitor cell, the hemangioblast: specifically, the human cord blood (CB) CD34+KDR+ cell fraction comprises primitive Hem and End cells, as well as hemangioblasts. In humans, the potential therapeutic role of Hem and End progenitors in ischemic heart disease is subject to intense investigation. Particularly, the contribution of these cells to angiogenesis and cardiomyogenesis in myocardial ischemia is not well established. In our studies, we induced myocardial infarct (MI) in the immunocompromised NOD-SCID mouse model, and monitored the effects of myocardial transplantation of human CB CD34+ cells on cardiac function.…
Anti‐laminin auto antibodies in ANCA‐associated vasculitis
2000
Background. Endothelial cell damage occurs during vasculitic processes in vivo. With the alteration of the endothelium, exposure to basement membrane components may occur with induction of humoral immunity. Methods. In the present study, we evaluated the prevalence of antibodies against the basement membrane antigen laminin (LMN) in patients with ANCA-associated systemic vasculitis (AASV), pathologic controls (systemic lupus erythematosus, mixed cryoglobulinaemia, Henoch Schonlein purpura, primary glomerulonephritis) and normal individuals. Results. By ELISA, 21.6% of AASV (16/74) and 10% of pathologic controls (3/30), but only one of the normal controls (2.8%) had these antibodies (P = 0.0…