Search results for "Helium"
showing 10 items of 1689 documents
NOSIP, a novel modulator of endothelial nitric oxide synthase activity.
2001
Production of nitric oxide (NO) in endothelial cells is regulated by direct interactions of endothelial nitric oxide synthase (eNOS) with effector proteins such as Ca2+-calmodulin, by posttranslational modifications such as phosphorylation via protein kinase B, and by translocation of the enzyme from the plasma membrane caveolae to intracellular compartments. Reversible acylation of eNOS is thought to contribute to the intracellular trafficking of the enzyme; however, protein factor(s) that govern the translocation of the enzyme are still unknown. Here we have used the yeast two-hybrid system and identified a novel 34 kDa protein, termed NOSIP (eNOS interacting protein), which avidly binds …
Presbyopia and the aging eye: Existing refractive approaches and their potential impact on dry eye signs and symptoms.
2020
Every part of the human body is subject to aging, including the eye. Increased prevalence of dry eye disease with age is widely acknowledged: aging threatens ocular surface homeostasis, altering the normal functioning of the lacrimal functional unit and potentially leading to signs and symptoms of dry eye. Parallelly, two additional degenerative processes take place within the crystalline lens, leading to presbyopia and cataractogenesis. With continuously increasing life expectancies both conditions are expected to impact society further. Correction strategies for presbyopia and cataracts either directly or indirectly challenge ocular surface additionally. On one hand, contact lens presbyop…
Antioxidant betalains from cactus pear (Opuntia ficus-indica) inhibit endothelial ICAM-1 expression.
2004
It has been suggested that some pigments would have antioxidant properties and that their presence in dietary constituents would contribute to reduce the risk of oxidative stress–correlated diseases. Among others, inflammatory response depends on redox status and may implicate oxidative stress. Vascular endothelial cells are a direct target of oxidative stress in inflammation. We have tested the impact of the free radical scavenger and antioxidant properties of betalains from the prickle pear in an in vitro model of endothelial cells. Here we show the capacity of betalains to protect endothelium from cytokine- induced redox state alteration, through ICAM-1 inhibition. KEYWORDS: endothelial …
Reconstruction of Peritoneal-like Structure in Three-Dimensional Collagen Gel Matrix Culture
1997
The peritoneum is a serous membrane consisting of different kinds of cells and extracellular matrix components (ECM). The aim of the present study was to develop a three-dimensional (3D) in vitro culture system for possible investigation of pathological conditions of the peritoneum. Human omental mesothelial cells (MC) and endothelial cells from the umbilical vein (EC) were cultivated either on (MC) or in (EC) a preformed type I collagen matrix. In 3D culture mesothelial cells showed their phenotypical in vivo characteristics and the synthesis of a new basal membrane (BM). Endothelial cells developed vessel-like structures, produce a BM and express E-selectin after TNF-alpha stimulation. Th…
Inflammation Determines the Pro-Adhesive Properties of High Extracellular D-Glucose in Human Endothelial Cells In Vitro and Rat Microvessels In Vivo
2010
BACKGROUND: Hyperglycemia is acknowledged as an independent risk factor for developing diabetes-associated atherosclerosis. At present, most therapeutic approaches are targeted at a tight glycemic control in diabetic patients, although this fails to prevent macrovascular complications of the disease. Indeed, it remains highly controversial whether or not the mere elevation of extracellular D-glucose can directly promote vascular inflammation, which favors early pro-atherosclerotic events. METHODS AND FINDINGS: In the present work, increasing extracellular D-glucose from 5.5 to 22 mmol/L was neither sufficient to induce intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion mo…
Heparin-binding protein targeted to mitochondrial compartments protects endothelial cells from apoptosis.
1999
Neutrophil-borne heparin-binding protein (HBP) is a multifunctional protein involved in the progression of inflammation. HBP is stored in neutrophil granules and released upon stimulation of the cells in proximity to endothelial cells. HBP affects endothelial cells in multiple ways; however, the molecular and cellular mechanisms underlying the interaction of HBP with these cells are unknown. Affinity isolation and enzymatic degradation demonstrated that HBP released from human neutrophils binds to endothelial cell-surface proteoglycans, such as syndecans and glypican. Flow cytometry indicated that a significant fraction of proteoglycan-bound HBP is taken up by the endothelial cells, and we …
Prostacyclin inhibits adhesion of polymorphonuclear leukocytes to human vascular endothelial cells due to adhesion molecule independent regulatory me…
2002
Prostacyclin is an important endothelial mediator involved in the interaction of neutrophils (PMN) with the vessel wall. Many studies have shown the beneficial effects of prostacyclin in ischemia and reperfusion. However, no previous study has investigated the direct effects of the prostacyclin analogs iloprost (ILO) and alprostadil (PGE(1)) on the endothelial part of the adhesion process. Human umbilical vein endothelial cells (HUVECs) were grown to confluence, stimulated with 300 U/ml TNF-alpha and treated with increasing concentrations of ILO and PGE(1). The cells were washed to remove TNF and the inhibitors and adhesion of fluorescence-green labeled PMN was determined microscopically. I…
Heavy metal ion induction of adhesion molecules and cytokines in human endothelial cells: the role of NF-kappaB, I kappaB-alpha and AP-1.
1997
We analyzed the influence of heavy-metal ions on human umbilical vein endothelial cells (HUVEC) in comparison to proinflammatory cytokines (TNF-alpha, IL-1beta) and lipopolysaccharide (LPS). Adhesion molecule and cytokine expressions are upregulated by heavy-metal exposure. Expression of E-selectin on the cell surface was strongly induced by 1-mM concentrations of NiCl2 and CoCl2, whereas ZnCl2 and CrCl3 had no influence. Furthermore, it is shown that NiCl2 induces mRNA expression of E-selectin, intercellular adhesion molecule-1, IL-6 and IL-8 in a 1-mM concentration. The transcription factor NF-kappaB is known to be involved in the regulation of adhesion molecule expression in endothelial …
Enzymatically modified, nonoxidized LDL induces selective adhesion and transmigration of monocytes and T-lymphocytes through human endothelial cell m…
1999
Abstract —Circulating monocytes and T lymphocytes extravasate through the endothelium at sites of developing atheromatous lesions, where they tend to accumulate and mediate the progression of the disease. We have previously demonstrated the presence of an enzymatically degraded, nonoxidized form of LDL (E-LDL) in early human fatty streaks, which possesses major biological properties of an atherogenic lipoprotein. The effects of E-LDL on human endothelial cells have now been studied with respect to adhesion and transmigration of monocytes and T lymphocytes. E-LDL induced a rapid and dose-dependent selective adhesion of monocytes and T lymphocytes to endothelial cell monolayers within 30 min…
Apigenin‐induced nitric oxide production involves calcium‐activated potassium channels and is responsible for antiangiogenic effects
2007
Summary. Background: The dietary flavonoid apigenin (Api) has been demonstrated to exert multiple beneficial effects upon the vascular endothelium. The aim of this study was to examine whether Ca2+-activated K+ channels (KCa) are involved in endothelial nitric oxide (NO) production and antiangiogenic effects.Methods: Endothelial NO generation was monitored using a cyclic guanosine monophosphate radioimmunoassay. KCa activity and changes of the intracellular Ca2+ concentration [Ca2+]i were analyzed using the fluorescent dyes bis-barbituric acid oxonol, potassium-binding benzofuran isophthalate, and fluo-3. The endothelial angiogenic parameters measured were cell proliferation, [3H]-thymidine…