Search results for "vessels"
showing 10 items of 348 documents
Rapid formation of plasma protein corona critically affects nanoparticle pathophysiology
2013
In biological fluids, proteins bind to the surface of nanoparticles to form a coating known as the protein corona, which can critically affect the interaction of the nanoparticles with living systems. As physiological systems are highly dynamic, it is important to obtain a time-resolved knowledge of protein-corona formation, development and biological relevancy. Here we show that label-free snapshot proteomics can be used to obtain quantitative time-resolved profiles of human plasma coronas formed on silica and polystyrene nanoparticles of various size and surface functionalization. Complex time- and nanoparticle-specific coronas, which comprise almost 300 different proteins, were found to …
Macrophage-mediated angiogenic activation of outgrowth endothelial cells in co-culture with primary osteoblasts.
2014
The successful vascularisation of complex tissue engineered constructs for bone regeneration is still a major challenge in the field of tissue engineering. In this context, co-culture systems of endothelial cells and osteoblasts represent a promising approach to advance the formation of a stable vasculature as well as an excellent in vitro model to identify factors that positively influence bone healing processes, including angiogenesis. Under physiological conditions, the activation phase of angiogenesis is mainly induced by hypoxia or inflammation. Inflammatory cells such as macrophages secrete proinflammatory cytokines and proangiogenic growth factors, finally leading to the formation of…
Progressive Development of Renal Vascular Dysfunction in Brain Death Implicates Reversible Alterations of Nitric Oxide Metabolism
2011
Vascular endothelial dysfunction occurs in the kidney graft from marginal brain death (BD) donors and may be responsible for a low success rate after transplantation.BD was induced in 16 dogs for 6 hours. Immediately after the inflation of the intracranial balloon, the treated group (n = 8) received 40 mg/kg bolus followed by 3 mg/kg/min infusion of L-arginine for 30 minutes. Renal vascular function and hemodynamic and biochemical parameters were determined.BD caused vasoconstriction, increase in renal venous nitrite (4.9 ± 0.8 versus 2.6 ± 0.1, P.05) and myeloperoxidase levels (1.43 ± 0.04 versus 2.43 ± 0.23, P.001), and reduced vasodilatation of renal artery to acetylcholine. Larginine di…
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…
Meox2/Tcf15 Heterodimers Program the Heart Capillary Endothelium for Cardiac Fatty Acid Uptake
2015
Background— Microvascular endothelium in different organs is specialized to fulfill the particular needs of parenchymal cells. However, specific information about heart capillary endothelial cells (ECs) is lacking. Methods and Results— Using microarray profiling on freshly isolated ECs from heart, brain, and liver, we revealed a genetic signature for microvascular heart ECs and identified Meox2/Tcf15 heterodimers as novel transcriptional determinants. This signature was largely shared with skeletal muscle and adipose tissue endothelium and was enriched in genes encoding fatty acid (FA) transport–related proteins. Using gain- and loss-of-function approaches, we showed that Meox2/Tcf15 media…
Collagen-embedded hydroxylapatite–beta-tricalcium phosphate–silicon dioxide bone substitute granules assist rapid vascularization and promote cell gr…
2010
In the present study we assessed the biocompatibility in vitro and in vivo of a low-temperature sol-gel-manufactured SiO(2)-based bone graft substitute. Human primary osteoblasts and the osteoblastic cell line, MG63, cultured on the SiO(2) biomatrix in monoculture retained their osteoblastic morphology and cellular functionality in vitro. The effect of the biomaterial in vivo and its vascularization potential was tested subcutaneously in Wistar rats and demonstrated both rapid vascularization and good integration within the peri-implant tissue. Scaffold degradation was progressive during the first month after implantation, with tartrate-resistant acid phosphatase-positive macrophages being …
Intracoronary application of C1 esterase inhibitor improves cardiac function and reduces myocardial necrosis in an experimental model of ischemia and…
1997
Background Myocardial injury from ischemia can be aggravated by reperfusion of the jeopardized area. The precise underlying mechanisms have not been clearly defined, but proinflammatory events, including complement activation, leukocyte adhesion, and infiltration and release of diverse mediators, probably play important roles. The present study addresses the possibility of reducing reperfusion damage by the application of C1 esterase inhibitor (C1-INH). Methods and Results Cardioprotection by C1-INH 20 IU/kg IC was examined in a pig model with 60 minutes of coronary occlusion, followed by 120 minutes of reperfusion. C1-INH was administered during the first 5 minutes of coronary reperfusion…
Ceramide Mediates Acute Oxygen Sensing in Vascular Tissues
2014
AbstractAims: A variety of vessels, such as resistance pulmonary arteries (PA) and fetoplacental arteries and the ductus arteriosus (DA) are specialized in sensing and responding to changes in oxygen tension. Despite opposite stimuli, normoxic DA contraction and hypoxic fetoplacental and PA vasoconstriction share some mechanistic features. Activation of neutral sphingomyelinase (nSMase) and subsequent ceramide production has been involved in hypoxic pulmonary vasoconstriction (HPV). Herein we aimed to study the possible role of nSMase-derived ceramide as a common factor in the acute oxygen-sensing function of specialized vascular tissues. Results: The nSMase inhibitor GW4869 and an anticera…
Reinterpreting the Magnetic Resonance Signs of Hemodynamic Impairment in the Brains of Multiple Sclerosis Patients From the Perspective of a Recent D…
2010
Multiple sclerosis patients examined with perfusion magnetic resonance (MR) imaging techniques have been found to have patterns of abnormal blood flow. These include prolonged mean transit time, a trend toward decreased cerebral blood flow in the area of plaques, and decreased cerebral blood flow and prolonged mean transit time within normal-appearing white matter. In-creased cerebral blood flow and volume and decreased mean transit time (compared with the baseline values before the relapse) were found to precede the development of plaques. In addition, susceptibility-weighted imaging utilizing deoxyhemoglobin as the contrast has revealed that venous blood in cerebral veins of multiple scle…
EphrinB2 controls vessel pruning through STAT1-JNK3 signalling
2014
Angiogenesis produces primitive vascular networks that need pruning to yield hierarchically organized and functional vessels. Despite the critical importance of vessel pruning to vessel patterning and function, the mechanisms regulating this process are not clear. Here we show that EphrinB2, a well-known player in angiogenesis, is an essential regulator of endothelial cell death and vessel pruning. This regulation depends upon phosphotyrosine-EphrinB2 signalling repressing c-jun N-terminal kinase 3 activity via STAT1. JNK3 activation causes endothelial cell death. In the absence of JNK3, hyaloid vessel physiological pruning is impaired, associated with abnormal persistence of hyaloid vessel…