scholarly journals Role of nitric oxide in heparin-induced attenuation of hypoxic pulmonary vascular remodeling

2002 ◽  
Vol 92 (5) ◽  
pp. 2012-2018 ◽  
Author(s):  
Damian J. Horstman ◽  
Lars G. Fischer ◽  
Peter C. Kouretas ◽  
Robert L. Hannan ◽  
George F. Rich
Keyword(s):  
Nitric Oxide ◽  
Vascular Remodeling ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Remodeling ◽  
Antiproliferative Effects ◽  
Coculture Model ◽  
Pulmonary Arterial ◽  
Nos Inhibitor

Heparin and nitric oxide (NO) attenuate changes to the pulmonary vasculature caused by prolonged hypoxia. Heparin may increase NO; therefore, we hypothesized that heparin may attenuate hypoxia-induced pulmonary vascular remodeling via a NO-mediated mechanism. In vivo, rats were exposed to normoxia (N) or hypoxia (H; 10% O2) with or without heparin (1,200 U · kg−1 · day−1) and/or the NO synthase (NOS) inhibitor N ω-nitro-l-arginine methyl ester (l-NAME; 20 mg · kg−1 · day−1) for 3 days or 3 wk. Heparin attenuated increases in pulmonary arterial pressure, the percentage of muscular pulmonary vessels, and their medial thickness induced by 3 wk of H. Importantly, althoughl-NAME alone had no effect, it prevented these effects of heparin on vascular remodeling. In H lungs, heparin increased NOS activity and cGMP levels at 3 days and 3 wk and endothelial NOS protein expression at 3 days but not at 3 wk. In vitro, heparin (10 and 100 U · kg−1 · ml−1) increased cGMP levels after 10 min and 24 h in N and anoxic (0% O2) endothelial cell-smooth muscle cell (SMC) coculture. SMC proliferation, assessed by 5-bromo-2′-deoxyuridine incorporation during a 3-h incubation period, was decreased by heparin under N, but not anoxic, conditions. The antiproliferative effects of heparin were not altered byl-NAME. In conclusion, the in vivo results suggest that attenuation of hypoxia-induced pulmonary vascular remodeling by heparin is NO mediated. Heparin increases cGMP in vitro; however, the heparin-induced decrease in SMC proliferation in the coculture model appears to be NO independent.

scholarly journals MiR-193-3p attenuates the vascular remodeling in pulmonary arterial hypertension by targeting PAK4

2020 ◽  
Vol 10 (4) ◽  
pp. 204589402097491
Author(s):  
Zhenhua Wu ◽  
Jie Geng ◽  
Yujuan Qi ◽  
Jian Li ◽  
Yaobang Bai ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Vascular Remodeling ◽  
Luciferase Reporter ◽  
Pulmonary Vascular Remodeling ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease associated with dysfunction of pulmonary artery endothelial cells and pulmonary artery smooth muscle cells (PASMCs). To explore the potential mechanism of miR-193-3p in pulmonary arterial hypertension, human PASMCs and rats were respectively stimulated by hypoxia and monocrotaline to establish PAH model in vivo and in vitro. The expressions of miR-193-3p and p21-activated protein kinase 4 (PAK4) in the lung samples of PAH patients and paired healthy samples from the healthy subjects in PHA cells and rats were detected by quantitative reverse transcriptase-PCR. Morphological changes in lung tissues were determined using hematoxylin and eosin staining. Right ventricular systolic pressure (RVSP) and ratio of right ventricle to left ventricle plus septum (RV/LV p S) were measured. The binding relationship between miR-193-3p and PAK4 was analyzed by TargetScan and verified by luciferase reporter assay. Cell viability, apoptosis, and migration were detected by 3-(4, 5-Dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide (MTT) flow cytometry, and wound-healing assays, respectively. The protein expressions of PAK4, proliferating cell nuclear antigen (PCNA), P21, p-AKT, and AKT in vivo or in vitro were determined by Western blot. In this study, we found that in pulmonary arterial hypertension, miR-193-3p expression was downregulated and PAK4 expression was up-regulated. MiR-193-3p directly targeted PAK4 and negatively regulated its expression. Hypoxia condition promoted cell proliferation, migration, and inhibited apoptosis accompanied with increased expressions of PCNA and p-AKT/AKT and decreased expression of P21 in PASMCs. MiR-193-3p overexpression attenuated the effects of hypoxia on PASMCs via downregulating PAK4. Monocrotaline treatment increased p-AKT/AKT and decreased P21 expression and caused pulmonary vascular remodeling in the model rats. MiR-193-3p overexpression attenuated pulmonary vascular remodeling, decreased p-AKT/AKT, and increased P21 levels via downregulating PAK4 in monocrotaline-induced rats. The results in this study demonstrated that upregulation of miR-193-3p reduced cell proliferation, migration, and apoptosis of PAH in vitro and pulmonary vascular remodeling in PAH in vivo through downregulating PAK4.

Fluorofenidone attenuates vascular remodeling in hypoxia-induced pulmonary hypertension of rats

2014 ◽  
Vol 92 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Xian-Wei Li ◽  
Jie Du ◽  
Gao-Yun Hu ◽  
Chang-Ping Hu ◽  
Dai Li ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Brdu Incorporation ◽  
Pulmonary Vascular Remodeling ◽  
Collagen Iii ◽  
Pulmonary Arterial

Fluorofenidone (AKF-PD) is a novel pyridone derivate that targets transforming growth factor-β1 (TGF-β1) signaling. Previous studies have proven that AKF-PD functions as an antifibrotic agent in pulmonary fibrosis and renal fibrosis models. Activated TGF-β1 signaling is thought to be a major feature of pulmonary hypertension (PH). TGF-β1 exerts powerful pro-proliferation effects on pulmonary arterial smooth muscle cells (PASMCs), and hence, prompts vascular remodeling. This study is designed to investigate the effect of AKF-PD on vascular remodeling in a rat model of hypoxia-induced PH. PH was induced in rats by 4 weeks of hypoxia. The expression of TGF-β1, collagen I, and collagen III was analyzed by ELISA, immunohistochemistry, real-time PCR, or Western blot. Proliferation of cultured PASMCs was determined by the BrdU incorporation method and flow cytometry. The results showed that AKF-PD treatment (0.5 or 1.0 g·(kg body mass)·d−1) for 4 weeks attenuated pulmonary vascular remodeling and improved homodynamic parameters. TGF-β1 level was significantly down-regulated by AKF-PD both in vivo and in vitro. Furthermore, hypoxia- and TGF-β1-induced PASMC proliferation and collagen expression were both significantly suppressed by AKF-PD. These results suggest that AKF-PD ameliorates the progression of PH induced by hypoxia in rats through its regulation of TGF-β1 expression, PASMC proliferation, and the extracellular matrix.

Comparison of the hemodynamic effects of nitric oxide and endothelium-dependent vasodilators in intact lungs

1990 ◽  
Vol 68 (2) ◽  
pp. 735-747 ◽  
Author(s):  
S. L. Archer ◽  
K. Rist ◽  
D. P. Nelson ◽  
E. G. DeMaster ◽  
N. Cowan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Methylene Blue ◽  
Pulmonary Hypertension ◽  
Feedback Inhibition ◽  
Pressor Response ◽  
Pulmonary Vasculature ◽  
Hemodynamic Effects ◽  
Isolated Lung

The effects of endothelium-dependent vasodilation on pulmonary vascular hemodynamics were evaluated in a variety of in vivo and in vitro models to determine 1) the comparability of the hemodynamic effects of acetylcholine (ACh), bradykinin (BK), nitric oxide (NO), and 8-bromo-guanosine 3′,5′-cyclic monophosphate (cGMP), 2) whether methylene blue is a useful inhibitor of endothelium-dependent relaxing factor (EDRF) activity in vivo, and 3) the effect of monocrotaline-induced pulmonary hypertension on the responsiveness of the pulmonary vasculature to ACh. In isolated rat lungs, which were preconstricted with hypoxia, ACh, BK, NO, and 8-bromo-cGMP caused pulmonary vasodilation, which was not inhibited by maximum tolerable doses of methylene blue. Methylene blue did not inhibit EDRF activity in any model, despite causing increased pulmonary vascular tone and responsiveness to various constrictor agents. There were significant differences in the hemodynamic characteristics of ACh, BK, and NO. In the isolated lung, BK and NO caused transient decreases of hypoxic vasoconstriction, whereas ACh caused more prolonged vasodilation. Pretreatment of these lungs with NO did not significantly inhibit ACh-induced vasodilation but caused BK to produce vasoconstriction. Tachyphylaxis, which was agonist specific, developed with repeated administration of ACh or BK but not NO. Tachyphylaxis probably resulted from inhibition of the endothelium-dependent vasodilation pathway proximal to NO synthesis, because it could be overcome by exogenous NO. Pretreatment with 8-bromo-cGMP decreased hypoxic pulmonary vasoconstriction and, even when the hypoxic pressor response had largely recovered, subsequent doses of ACh and NO failed to cause vasodilation, although BK produced vasoconstriction. These findings are compatible with the existence of feedback inhibition of the endothelium-dependent relaxation by elevation of cGMP levels. Responsiveness to ACh was retained in lungs with severe monocrotaline-induced pulmonary hypertension. Many of these findings would not have been predicted based on in vitro studies and illustrate the importance for expanding studies of EDRF to in vivo and ex vivo models.

Divergent contractile and structural responses of the murine PKC-ε null pulmonary circulation to chronic hypoxia

2005 ◽  
Vol 289 (6) ◽  
pp. L1083-L1093 ◽  
Author(s):  
C. M. Littler ◽  
C. A. Wehling ◽  
M. J. Wick ◽  
K. A. Fagan ◽  
C. D. Cool ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Circulation ◽  
Vascular Remodeling ◽  
Vascular Tone ◽  
Chronic Hypoxia ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Systolic Pressure ◽  
Structural Response ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Remodeling

Loss of PKC-ε limits the magnitude of acute hypoxic pulmonary vasoconstriction (HPV) in the mouse. Therefore, we hypothesized that loss of PKC-ε would decrease the contractile and/or structural response of the murine pulmonary circulation to chronic hypoxia (Hx). However, the pattern of lung vascular responses to chronic Hx may or may not be predicted by the acute HPV response. Adult PKC-ε wild-type (PKC-ε+/+), heterozygous null, and homozygous null (PKC-ε−/−) mice were exposed to normoxia or Hx for 5 wk. PKC-ε−/− mice actually had a greater increase in right ventricular (RV) systolic pressure, RV mass, and hematocrit in response to chronic Hx than PKC-ε+/+ mice. In contrast to the augmented PA pressure and RV hypertrophy, pulmonary vascular remodeling was increased less than expected (i.e., equal to PKC-ε+/+ mice) in both the proximal and distal PKC-ε−/− pulmonary vasculature. The contribution of increased vascular tone to this pulmonary hypertension (PHTN) was assessed by measuring the acute vasodilator response to nitric oxide (NO). Acute inhalation of NO reversed the increased PA pressure in hypoxic PKC-ε−/− mice, implying that the exaggerated PHTN may be due to a relative deficiency in nitric oxide synthase (NOS). Despite the higher PA pressure, chronic Hx stimulated less of an increase in lung endothelial (e) and inducible (i) NOS expression in PKC-ε−/− than PKC-ε+/+ mice. In contrast, expression of nNOS in PKC-ε+/+ mice decreased in response to chronic Hx, while lung levels in PKC-ε−/− mice remained unchanged. In summary, loss of PKC-ε results in increased vascular tone, but not pulmonary vascular remodeling in response to chronic Hx. Blunting of Hx-induced eNOS and iNOS expression may contribute to the increased vascular tone. PKC-ε appears to be an important signaling intermediate in the hypoxic regulation of each NOS isoform.

scholarly journals LncRNA-SMILR modulates RhoA/ROCK signaling by targeting miR-141 to regulate vascular remodeling in pulmonary arterial hypertension

2020 ◽  
Vol 319 (2) ◽  
pp. H377-H391 ◽  
Author(s):  
Si Lei ◽  
Fei Peng ◽  
Mei-Lei Li ◽  
Wen-Bing Duan ◽  
Cai-Qin Peng ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Long Noncoding Rna ◽  
Vascular Remodeling ◽  
Noncoding Rna ◽  
In Vivo Models ◽  
Pulmonary Arterial

Smooth muscle-enriched long noncoding RNA (SMILR), as a long noncoding RNA (lncRNA), was increased in pulmonary arterial hypertension (PAH) patients and in vitro and in vivo models. SMILR activated RhoA/ROCK signaling by targeting miR-141 to disinhibit its downstream target RhoA. SMILR knockdown or miR-141 overexpression inhibited hypoxia-induced cell proliferation and migration via repressing RhoA/ROCK signaling in pulmonary arterial smooth muscle cells (PASMCs), which was confirmed in vivo experiments that knockdown of SMILR inhibited vascular remodeling and alleviated PAH in rats. SMILR may be a promising and novel therapeutic target for the treatment and drug development of PAH.

EXPERIMENTAL RESEARCH OF SIMVASTATIN IN REVERSING PULMONARY VASCULAR REMODELING IN VIVO AND IN VITRO

PEDIATRICS ◽  
2008 ◽  
Vol 121 (Supplement 2) ◽  
pp. S95.2-S95
Author(s):  
Hanmin Liu ◽  
Bin Liu ◽  
Yimin Hua ◽  
Xiaoqin Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Experimental Research ◽  
Vascular Remodeling ◽  
Pulmonary Vascular Remodeling

scholarly journals Islet constitutive nitric oxide synthase and glucose regulation of insulin release in mice

1999 ◽  
Vol 163 (1) ◽  
pp. 39-48 ◽  
Author(s):  
B Akesson ◽  
R Henningsson ◽  
A Salehi ◽  
I Lundquist
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Insulin Release ◽  
Ex Vivo ◽  
Insulin Response ◽  
Glucose Regulation ◽  
Nos Inhibitor ◽  
Oxide Synthase

We have studied, by a combined in vitro and in vivo approach, the relation between the inhibitory action of N(G)-nitro-l-arginine methyl ester (L-NAME), a selective inhibitor of nitric oxide synthase (NOS), on the activity of islet constitutive NOS (cNOS) and glucose regulation of islet hormone release in mice. The cNOS activity in islets incubated in vitro at 20 mM glucose was not appreciably affected by 0.05 or 0.5 mM L-NAME, but was greatly suppressed (-60%) by 5 mM L-NAME. Similarly, glucose-stimulated insulin release was unaffected by the lower concentrations of L-NAME but greatly enhanced in the presence of 5 mM of the NOS inhibitor. In incubated islets inhibition of cNOS activity resulted in a modestly enhanced insulin release in the absence of glucose, did not display any effect at physiological or subphysiological glucose concentrations, but resulted in a markedly potentiated insulin release at hyperglycaemic glucose concentrations. In the absence of glucose, glucagon secretion was suppressed by L-NAME. The dynamics of glucose-induced insulin release and (45)Ca(2+) efflux from perifused islets revealed that L-NAME caused an immediate potentiation of insulin release, and a slight increase in (45)Ca(2+) efflux. In islets depolarized with 30 mM K(+) in the presence of the K(+)(ATP) channel opener, diazoxide, L-NAME still greatly potentiated glucose-induced insulin release. Finally, an i.v. injection of glucose to mice pretreated with L-NAME was followed by a markedly potentiated insulin response, and an improved glucose tolerance. In accordance, islets isolated directly ex vivo after L-NAME injection displayed a markedly reduced cNOS activity. In conclusion, we have shown here, for the first time, that biochemically verified suppression of islet cNOS activity, induced by the NOS inhibitor L-NAME, is accompanied by a marked potentiation of glucose-stimulated insulin release both in vitro and in vivo. The major action of NO to inhibit glucose-induced insulin release is probably not primarily linked to changes in Ca(2+) fluxes and is exerted mainly independently of membrane depolarization events.

scholarly journals Baicalin prevents pulmonary arterial remodeling in vivo via the AKT/ERK/NF-κB signaling pathways

2019 ◽  
Vol 9 (4) ◽  
pp. 204589401987859 ◽  
Author(s):  
Guosen Yan ◽  
Jinxia Wang ◽  
Tao Yi ◽  
Junfen Cheng ◽  
Haixu Guo ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Right Ventricular ◽  
Signaling Pathways ◽  
Vascular Remodeling ◽  
Systolic Pressure ◽  
Pulmonary Vascular Remodeling ◽  
Ventricular Systolic Pressure ◽  
Pulmonary Arterial

Pulmonary arterial hypertension is a rapidly progressive and often fatal disease. As the pathogenesis of pulmonary arterial hypertension remains unclear, there is currently no good drug for pulmonary arterial hypertension and new therapy is desperately needed. This study investigated the effects and mechanism of baicalin on vascular remodeling in rats with pulmonary arterial hypertension. A rat pulmonary arterial hypertension model was constructed using intraperitoneal injection of monocrotaline, and different doses of baicalin were used to treat these rats. The mean pulmonary arterial pressure (mPAP) and right ventricular systolic pressure (RVSP) were measured with a right heart catheter. Moreover, the hearts were dissected to determine the right ventricular hypertrophy index (RVHI). The lung tissues were stained with H&E and Masson's staining to estimate the pulmonary vascular remodeling and collagen fibrosis, and the expression of proteins in the AKT, ERK, and NF-κB p65 phosphorylation (p-AKT, p-ERK, p-p65) was examined by Western blot analysis. We found that compared with untreated pulmonary arterial hypertension rats, baicalin ameliorated pulmonary vascular remodeling and cardiorespiratory injury, inhibited p-p65 and p-ERK expression, and promoted p-AKT and p-eNOS expression. In conclusion, baicalin interfered with pulmonary vascular remodeling and pulmonary arterial hypertension development in rats through the AKT/eNOS, ERK and NF-κB signaling pathways.

eNOS expression is not altered in pulmonary vascular remodeling due to increased pulmonary blood flow

1998 ◽  
Vol 274 (6) ◽  
pp. L1058-L1065 ◽  
Author(s):  
Allen D. Everett ◽  
Timothy D. Le Cras ◽  
Chun Xue ◽  
Roger A. Johns
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Smooth Muscle ◽  
Vascular Remodeling ◽  
Pulmonary Blood Flow ◽  
Nuclear Antigen ◽  
Mrna Levels ◽  
Altered Expression ◽  
Pulmonary Vascular Remodeling ◽  
Pulmonary Arterial

Congenital heart lesions resulting in increased pulmonary blood flow are common and if unrepaired often lead to pulmonary hypertension and heart failure. Therefore, we hypothesized that increased pulmonary blood flow without changes in pressure would result in remodeling of the pulmonary arterial wall. Furthermore, because the vasodilator nitric oxide is produced by the lung, is regulated by flow in the systemic circulation, and has been associated with the regulation of smooth muscle cell proliferation, we hypothesized that increased pulmonary blood flow would result in altered expression of endothelial nitric oxide synthase (eNOS). To study this hypothesis, 42-day-old Sprague-Dawley rats had creation of an aortocaval shunt to increase pulmonary blood flow for 6 wk. The shunt resulted in a significant increase in the heart- and lung-to-body weight ratios (>2-fold; P < 0.05) without significant alteration of pulmonary or systemic blood pressures. Significant thickening of the pulmonary arterial medial wall developed, with increased muscularization of small (50–100 μm)- and medium (101–200 μm)-sized arteries as evidenced by α-actin smooth muscle staining. Proliferating cell nuclear antigen staining and bromodeoxyuridine labeling did not detect proliferating smooth muscle cells in the vascular wall. eNOS Western and Northern blot analyses and immunohistochemical staining demonstrated that eNOS protein and mRNA levels were not altered in the shunt lungs compared with sham controls. Therefore, increased pulmonary flow without increased pressure resulted in pulmonary artery medial thickening, without ongoing proliferation. Unlike chronic hypoxia-induced vascular remodeling, the pulmonary vascular remodeling resulting from increased pulmonary blood flow is not associated with changes in eNOS.

Inhibition of nitric oxide synthase augments myocardial contractile responses to beta-adrenergic stimulation

1996 ◽  
Vol 271 (6) ◽  
pp. H2646-H2652 ◽  
Author(s):  
J. F. Keaney ◽  
J. M. Hare ◽  
J. L. Balligand ◽  
J. Loscalzo ◽  
T. W. Smith ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Myocardial Contractility ◽  
Adrenergic Stimulation ◽  
Maximum Increase ◽  
Beta Adrenergic ◽  
Before And After ◽  
Nos Inhibitor ◽  
Oxide Synthase

Recent in vitro evidence suggests a role for nitric oxide (NO) in the modulation of myocardial contractility. The specific role of NO in the control of cardiac function in vivo, however, remains unclear. We investigated the effect of NO synthase (NOS) inhibition on myocardial contractility in response to beta-adrenergic stimulation in autonomically blocked dogs. Intracoronary infusions of dobutamine (1-50 micrograms/min) and isoproterenol (0.1 and 0.5 microgram/min) were performed before and after the intracoronary administration of the specific NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Intracoronary dobutamine resulted in a dose-dependent increase in peak first derivative of pressure (dP/dtmax) to a maximum of 195 +/- 10% (P < 0.001). After inhibition of NOS with intracoronary L-NAME at rates of 0.1 and 1 mg/min, the response to dobutamine was significantly enhanced with dP/dtmax, increasing 276 +/- 17 and 317 +/- 26%, respectively (P < 0.001). Intracoronary isoproterenol resulted in a maximum increase in dP/dtmax of 116 +/- 15% (P < 0.001) that further increased to 154 +/- 17 and 157 +/- 18% after NOS inhibition with 0.1 and 1 mg/min L-NAME, respectively (both P < 0.002). L-NAME had no effect on baseline dP/dtmax but did produce a reduction in myocardial guanosine 3',5'-cyclic monophosphate content. These results suggest a role for NO in the control of myocardial contractility in response to beta-adrenergic stimulation in vivo.

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