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Query: UMLS:C0406810 (
NAME
)
13,345
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We investigated the effects of
vascular endothelial growth factor
(VEGF(165)) on [Ca(2+)](i)-transient in cultured lymphatic endothelial cells (LEC) and mechanical activity of isolated dog thoracic ducts. VEGF (0.1-10 ng/ml) caused a dose-dependent increase of the [Ca(2+)](i) in LEC. Pretreatment with 10(-5) M genistein or 5x10(-6) M herbimycin A produced a significant reduction of the VEGF-induced [Ca(2+)](i)-transient. In the presence of 10(-6) M thapsigargin, VEGF caused no significant effect on the [Ca(2+)](i)-transient. Pretreatment with Ca(2+)-free solution containing 0.1 mM EGTA produced no significant effect on the peak increase of [Ca(2+)](i) induced by 0.1 or 10 ng/ml VEGF, but significantly depressed the sustained part of [Ca(2+)](i) observed at the higher concentration of VEGF. The VEGF (0.1-10 ng/ml) caused a significant dilation of the isolated lymph vessels with intact endothelium, which were precontracted with U46,619. The 10 ng/ml VEGF-induced dilation was significantly reduced by 3 x 10(-5) M N(omega)-nitro-L-arginine methyl ester (L-
NAME
). The action of L-
NAME
was inhibited by the simultaneous application of 10(-3) M L-arginine. Mechanical rubbing of the endothelium also caused significant inhibition of the VEGF-induced dilation. The findings suggest that VEGF(165) may activate the receptor-related tyrosine kinase and cause the release of Ca(2+) from the inositol 1,4, 5-triphosphate-sensitive intracellular Ca(2+) stores in LEC. VEGF(165) also produces endothelium-dependent nitric oxide-mediated dilation of the precontracted isolated lymph vessels.
...
PMID:Effects of VEGF on Ca(2+)-transient in cultured lymphatic endothelial cells and mechanical activity of isolated lymph vessels. 1101 85
The role of
vascular endothelial growth factor
(
VEGF
), a potent endothelium-specific angiogenic factor, in the regulation of angiotensin-converting enzyme (ACE) in cultured human umbilical vein endothelial cells (HUVECs) was studied.
VEGF
(0.07-1.2 x 10(-6) mmol/l) caused a dose-dependent increase in ACE measured in intact endothelial cells and increased the expression of ACE mRNA. The stimulatory effect of
VEGF
was inhibited by pretreatment of endothelial cells with the tyrosine kinase inhibitor herbimycin (4.35 x 10(-5) mmol/l). The stimulatory effect of
VEGF
was potentiated by the selective cGMP phosphodiesterase inhibitor zaprinast (0.1 mmol/l). The nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-
NAME
; 5.4 mmol/l) suppressed the stimulatory effect of
VEGF
. The nonselective cyclooxygenase (COX) inhibitor indomethacin (5 microM) and the selective COX-2 inhibitor NS-398 (5 microM) potentiated the stimulatory effect of
VEGF
, whereas the selective COX-1 inhibitor resveratrol (5 microM) was without effect. ACE induction by
VEGF
was inhibited by the selective protein kinase C (PKC) inhibitor GF109203X (2.5 x 10(-3) mmol/l) and by downregulating PKC with phorbol 12-myristate 13-acetate. In summary,
VEGF
induced ACE in cultured HUVECs. Intracellular events such as tyrosine kinase activation, PKC activation, and increase of cGMP were probably involved in ACE induction by
VEGF
. Nitric oxide may partially contribute to ACE induction by
VEGF
. The powerful capacity of
VEGF
to increase ACE in endothelial cells shown here suggests a synergistic relation between
VEGF
and the renin-angiotensin system in vascular biology and pathophysiology.
...
PMID:Upregulation of angiotensin-converting enzyme by vascular endothelial growth factor. 1115 90
The angiogenic proteins basic fibroblast growth factor (bFGF; FGF-2) and
vascular endothelial growth factor
121 (VEGF(121)) are each able to enhance the collateral-dependent blood flow after bilateral femoral artery ligation in rats. To study the effect of nitric oxide (NO) synthase (NOS) inhibition on bFGF- or VEGF(121)-induced blood flow expansion, the femoral arteries of male Sprague-Dawley rats were ligated bilaterally, and the animals were given tap water [non-N(G)-nitro-L-arginine methyl ester (L-
NAME
) group; n = 36] or water that contained L-
NAME
(L-
NAME
group; 2 mg/ml, n = 36). Animals from each group were further divided into three subgroups: vehicle (n = 12), bFGF (5 microg x kg(-1) x day(-1), n = 12), or VEGF(121) (10 microg x kg(-1) x day(-1), n = 12). Growth factors were delivered via intra-arterial infusion with osmotic pumps over days 1-14. On day 16, after a 2-day delay to permit clearance of bFGF and VEGF from the circulation, maximal collateral blood flow was determined by (85)Sr- and (141)Ce-labeled microspheres during treadmill running. L-
NAME
(approximately 137 mg x kg(-1) x day(-1)) for 18 days increased systemic blood pressure (approximately 26%, P<0.001). In the absence of L-
NAME
, collateral-dependent blood flows to the calf muscles were greater in the VEGF(121)- and bFGF-treated subgroups (85 +/- 4.5 and 80 +/- 2.9 ml x min(-1) x 100 g(-1), respectively) than in the vehicle subgroup (49 +/- 3.0 ml x min(-1) x 100 g(-1), P<0.001). In the presence of NOS inhibition by L-
NAME
, blood flows to the calf muscles were essentially equivalent among the three subgroups (54 +/- 3.0, 56 +/- 5.1, and 47 +/- 2.0 ml x min(-1) x 100 g(-1) in the bFGF-, VEGF(121)-, and vehicle-treated subgroups, respectively) and were not different from the blood flow in the non-L-
NAME
vehicle subgroup. Our results therefore indicate that normal NO production is essential for the enhanced vascular remodeling induced by exogenous bFGF or VEGF(121) in this rat model of experimental peripheral arterial insufficiency. These results imply that a blunted endothelial NO production could temper vascular remodeling in response to these angiogenic growth factors.
...
PMID:VEGF(121)- and bFGF-induced increase in collateral blood flow requires normal nitric oxide production. 1117 52
Adenovirus is a widely used vector for cancer gene therapy because of its high infection efficiency and capacity for transgene expression in both dividing and nondividing cells. However, neutralisation of adenovirus by pre-existing antibodies can lead to inefficient delivery, and the wide tissue distribution of the coxsackie and adenovirus receptor (
CAR
, the primary receptor for adenovirus type 5) precludes target selectivity. These limitations have largely restricted therapeutic use of adenovirus to local or direct administration. A successful viral gene therapy vector would be protected from neutralising antibodies and exhibit a preferential tropism for target cells. We report here the development of a covalent coating and retargeting strategy using a multivalent hydrophilic polymer based on poly-[N-(2-hydroxypropyl)methacrylamide] (pHPMA). Incorporation of targeting ligands such as basic fibroblast growth factor and
vascular endothelial growth factor
on to the polymer-coated virus produces ligand-mediated,
CAR
-independent binding and uptake into cells bearing appropriate receptors. Retargeted virus is resistant to antibody neutralisation and can infect receptor-positive target cells selectively in mixed culture, and also in xenografts in vivo. Multivalent polymeric modification of adenovirus is an effective way of changing its tropism and interaction with the immune system. As a non-genetic one-step process, the technology is simple, versatile and should yield vectors with an improved safety profile.
...
PMID:Polymer-coated adenovirus permits efficient retargeting and evades neutralising antibodies. 1131 9
The trophoblast-like choriocarcinoma cell line BeWo expresses a receptor for
vascular endothelial growth factor
(
VEGF
) and proliferates in response to
VEGF
. Nitric oxide (NO) seems to play a key role in the
VEGF
-induced proliferation of endothelial cells but the NO mechanistic regulation of
VEGF
-stimulated trophoblast proliferation is presently unclear. We assessed the effect of exogenous
VEGF
on BeWo cell proliferation by [3H]thymidine incorporation. The
VEGF
-induced proliferation of BeWo cells was significantly increased by the NO synthase (NOS) inhibitor, N(omega)-nitro-l-arginine methyl ester (L-
NAME
), but was inhibited by the NO donor, sodium nitroprusside. Treatment of the cells with 10 ng/ml of
VEGF
increased not only eNOS expression but also NO production. The extracellular signal-regulated kinase (Erk) of the mitogen-activated protein kinase (MAPK) family was activated by
VEGF
as demonstrated by the phosphorylation of Erk in Western blots. The effects of
VEGF
on NO production and the expression of endothelial NOS (eNOS) were attenuated by treating BeWo cells with the selective inhibitor of MAPK kinase, PD98059.
VEGF
-stimulated proliferation of BeWo cells was inhibited by the tyrosine kinase inhibitor genistein but increased by PD98059. Other kinase inhibitors, including LY294002 (phosphoinositide 3-kinase inhibitor) and SB203580 (P38 MAPK inhibitor), had no effect on the proliferation of the cells and NO production. These results indicate that endogenous NO production down-regulates the
VEGF
-stimulated proliferation of BeWo cells and that the activation of Erk plays an important role in this mechanism.
...
PMID:Endogenous production of nitric oxide by vascular endothelial growth factor down-regulates proliferation of choriocarcinoma cells. 1135 60
Although accumulating lines of evidence indicate the proangiogenic role of angiotensin II (Ang II), little is known about the molecular mechanisms associated with such an effect. This study aimed to identify molecular events involved in Ang II-induced angiogenesis in the Matrigel model in mice. C57Bl/6 female mice received a subcutaneous injection of either Matrigel or Matrigel with Ang II (10(-7) M) alone, with Ang II and an AT1 receptor antagonist (candesartan, 10(-6) M), or with Ang II and AT2 receptor antagonist (PD123319, 10(-6) M). After 14 days, angiogenesis was assessed in the Matrigel-plug by histological evaluation and cellular counting. Ang II increased by 1.9-fold the number of cells within the Matrigel (p < 0.01 versus control). Immunohistological analysis revealed the presence of macrophages, endothelial and smooth muscle cells, and the development of vascular-like structure. Such an angiogenic effect was associated with an increase in
vascular endothelial growth factor
(
VEGF
) (1.5-fold, p < 0.01), endothelial nitric oxide (eNOS) (1.7-fold, p < 0.01), and cyclooxygenase-2 (1.4-fold, p < 0.05) protein levels measured by Western blotting. Conversely, Ang II treatment did not affect MMP-9 and MMP-2 activity, assessed by zymography. Blockade of AT1 receptor completely prevented the Ang II-induced angiogenesis and protein regulations, whereas that of AT2 was ineffective. Administration of
VEGF
neutralizing antibody (2.5 microg ip twice a week) and cyclooxygenase-2 selective inhibitor (nimesulide, 30 mg/L) also hampered Ang II proangiogenic effect. In addition, Ang II-induced cell ingrowth was impaired by treatment with nitric oxide synthase inhibitor (L-
NAME
, 10 mg/kg/day) and in eNOS-deficient mice. Therefore, in an in vivo model, Ang II induced angiogenesis through AT1 receptor, which involved activation of
VEGF
/eNOS-related pathway and of the inflammatory process.
...
PMID:Angiotensin II angiogenic effect in vivo involves vascular endothelial growth factor- and inflammation-related pathways. 1206 85
A loss of the microvascular endothelium occurs in the remnant kidney model of renal disease and may play an important role in progression (Kang et al, J Am Soc Nephrol, 12:1434, 2001). Given that nitric oxide (NO) is a potent endothelial cell survival factor, we hypothesized that stimulating (with L-arginine) or blocking (with nitro-L-arginine methyl ester, (L-
NAME
)) NO synthesis could modulate the integrity of the microvasculature and hence affect progression of renal disease. Rats underwent 5/6 nephrectomy (RK) and then were randomized at 4 weeks to receive vehicle, L-
NAME
, or L-arginine for 4 weeks. Systolic blood pressure and renal function was measured, and tissues were collected at 8 weeks for histological and molecular analyses. The effect of modulation of NO on
vascular endothelial growth factor
(
VEGF
) expression in rat aortic vascular smooth muscle cells (SMC) and mouse medullary thick ascending limb tubular epithelial cells (mTAL) was also studied. Inhibition of NO with L-
NAME
was associated with more rapid progression compared to RK alone, with worse blood pressure, proteinuria, renal function, glomerulosclerosis, and tubulointerstitial fibrosis. The injury was also associated with more glomerular and peritubular capillary endothelial cell loss in association with an impaired endothelial proliferative response. Interestingly, the preglomerular endothelium remained intact or was occasionally hyperplastic, and this was associated with a pronounced proliferation of the vascular SMCs with de novo expression of
VEGF
. Cell culture studies confirmed a divergent effect of NO inhibition on
VEGF
expression, with inhibition of
VEGF
synthesis in mTAL cells and stimulation of
VEGF
in vascular SMC. In contrast to the effects of NO inhibition, stimulation of NO with L-arginine had minimal effects in this rat model of progressive renal disease. These studies confirm that blockade of NO synthesis accelerates progression of renal disease in the remnant kidney model, and support the hypothesis that one of the pathogenic mechanisms may involve accelerated capillary loss and impaired angiogenesis of the renal microvasculature. Interestingly, inhibition of NO synthesis did not lead to a loss of the preglomerular endothelium, which may relate to the effect of NO blockade to stimulate
VEGF
synthesis in the adjacent vascular smooth muscle cell.
...
PMID:Nitric oxide modulates vascular disease in the remnant kidney model. 1210 8
A novel murine model of aging (kl/kl mice) has been developed by in vivo mutagenesis. We analyzed endothelial function in this strain. Ring preparations of the thoracic aorta were obtained from 6- to 9-week old wild-type (+/+) and heterozygous (kl/+) klotho mice. The aortas of kl/+ mice showed an exaggerated contractile response to norepinephrine and attenuated vasodilator responses to acetylcholine and lecithinized superoxide dismutase (SOD) compared to +/+ mice. The response to sodium nitroprusside was unaltered in kl/+ mice. The contraction in response to norepinephrine was augmented by treatment with N(G)-nitro-L-arginine methyl ester (L-
NAME
, 10(-5) M) to a greater extent in +/+ mice than in kl/+ mice. Treatment with L-
NAME
abolished the vasodilator responses to both acetylcholine and lecithinized SOD. NO metabolites (NO2- and NO3-) and cGMP concentrations in the urine were significantly reduced in kl/+ mice compared to +/+ mice. However, the urinary excretion of 6-keto-prostaglandin F1alpha was unaltered. There was little immunostaining for NO synthase and
vascular endothelial growth factor
(
VEGF
) in the aorta of kl/+ mice. No immunostaining for NO synthase was noted in the aorta of kl/kl mice. The expression of the klotho gene product may have a role in the regulation of
VEGF
expression and is tightly linked to endothelial release of NO.
...
PMID:Production of nitric oxide, but not prostacyclin, is reduced in klotho mice. 1212 Jul 57
Chronic inhibition of nitric oxide (NO) synthesis by oral administration of N(G)-nitro-L-arginine methyl ester (L-
NAME
) causes hypertension and produces arteriosclerosis in rats. Balloon injury induces upregulation of
vascular endothelial growth factor
(
VEGF
) in medial smooth muscle cells of the rat arterial wall, and NO secreted by a restored endothelium acts as the negative feedback mechanism that downregulates
VEGF
expression to basal levels. In this study, we tested the hypothesis that a reciprocal relation between
VEGF
and NO would be established in a rat model of chronic NO blockade. Male Wister rats received plain drinking water (n = 10) or L-
NAME
(0.5 mg/ml) in the drinking water (n = 11) for 6 weeks. After 6 weeks, the wall-to-lumen ratios and perivascular fibrosis in the coronary arteries were greater in the L-
NAME
group than in the control group. NO synthase-positive cells in the intima were abundantly observed in the control group, whereas no such cells were seen in the L-
NAME
group. In contrast, the number of
VEGF
-positive smooth muscle cells in the media was greater in the L-
NAME
group than in the control group. These findings strongly suggest a reciprocal relation between
VEGF
and NO even in a rat model of chronic NO blockade.
...
PMID:Reciprocal expression of vascular endothelial growth factor and nitric oxide synthase by coronary arterial wall cells during chronic inhibition of nitric oxide synthesis in rats. 1221 34
The present study was designed to evaluate the role of nitric oxide (NO) for angiogenesis. Angiogenesis was elicited upon mouse cornea by chemical cautery with silver nitrate. Angiogenic activity was evaluated by measuring the length of vascular sprout with or without administration of NO synthase (NOS) inhibitor, N((G))-nitro-L-arginine-methyl ester (L-
NAME
). In the pericorneal plexus, a circulatory loop situated in the same topological situation for all individuals was selected to observe vascular sprouting. At 72 h after cauterization, the length of the longest vascular sprout was measured using the perfused whole-mount cornea. The length of nontreated mice (83 +/- 83 microm) was significantly longer than that of L-
NAME
treated mice (33 +/- 24.6 microm). To address the possible contribution of production of
vascular endothelial growth factor
(
VEGF
) and NO, we measured mRNAs of
VEGF
and inducible NOS. The mRNA level of
VEGF
increased to 170% of the nontreated level at 12 h after cauterization and returned to the nontreated level by 24 h after cauterization. mRNA of inducible NOS remained elevated 24 h after cauterization. These results suggest that the response of preexisting vessels to angiogenic stimulus via NO is of importance in the process of angiogenesis, i.e., vascular sprouting is promoted by NO production. This might be attributable to enhancement of an increase in vascular permeability and /or vasodilation via NO.
...
PMID:Nitric oxide synthase inhibition by N(G)-nitro-L-arginine methyl ester retards vascular sprouting in angiogenesis. 1253 65
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