Abstract 18587: Downregulation of Pulmonary Artery Endothelial Catechol-o-methyltransferase Activity by Aldosterone Increases Norepinephrine Levels in Pulmonary Arterial Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Samantha Torquato ◽  
Kiyotake Ishikawa ◽  
Jaume Aguerro ◽  
Bradley A Maron ◽  
Joseph Loscalzo ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Right Heart Failure ◽  
Therapeutic Interventions ◽  
Pulmonary Vasculature ◽  
Methyltransferase Activity ◽  
Comt Activity ◽  
Pulmonary Arterial

Elevated levels of norepinephrine (NE) occur in pulmonary arterial hypertension (PAH) and are determined, in part, by the activity of catechol- O -methyltransferase (COMT). COMT degrades catecholamines, is negatively regulated by calcium, and is expressed by pulmonary artery endothelial cells (PAEC). As hyperaldosteronism occurs in PAH and aldosterone (ALDO) influences calcium levels, we hypothesized that ALDO decreases COMT activity to increase NE levels in PAH. Accordingly, human PAEC were treated with ALDO (10 -7 mol/L), a level that is achieved clinically in PAH, for up to 72 h. Compared to vehicle-treated PAEC, ALDO decreased COMT activity by 59.2 ± 6.2% (p<0.01) to increase NE levels in the medium (122.4 ± 11.8 vs. 210.7 ± 15.5 pg/mL/mg protein, p<0.01). This occurred as a result of an ALDO-mediated decrease in COMT protein expression by 52.6 ± 9.3% (p<0.01) as well as an increase in intracellular calcium levels (102.9 ± 21.0 vs. 167.7 ± 17.8 nmol/L, p<0.05) to inhibit activity. These effects were abrogated by coincubation with spironolactone. To determine the in vivo relevance of these findings, COMT was examined in the rat monocrotaline model of PAH with confirmed hyperALDO. COMT was decreased (47.6 ± 10.2 %control, p<0.05) in remodeled pulmonary arterioles with a concomitant increase in lung NE levels (432.8 ± 44.5 vs. 899.7 ± 34.2 pg/mL, p<0.01) compared to control rats. In the porcine pulmonary vein banding model of pulmonary hypertension (PH-pigs) with elevated mean pulmonary artery pressure (15[13-15] vs. 35[27-43], p<0.01) and pulmonary vascular resistance (PVR) index (1.97[1.74-2.28] vs. 5.78[2.61-8.75], p <0.05), ALDO levels were also increased (27.1 ± 5.1 vs. 60.8 ± 10.6 pg/mL, p<0.03) in advance of right heart failure as compared to sham controls. PH-pigs demonstrated a 48.3 ± 9.9% (p<0.02) decrease in pulmonary vascular COMT expression and an increase in NE levels (114.6 ± 20.2 vs. 1,622.6 ± 489.2 pg/mL, p<0.02) that correlated positively with ALDO levels (R 2 =0.58, p<0.02). These findings were confirmed in patients with PAH. Together, these data indicate that there is crosstalk in the pulmonary vasculature between ALDO and the sympathetic nervous system to regulate NE levels in PAH, and thus, have implications for therapeutic interventions.

scholarly journals Traditional Herbal Medicine Discovery for the Treatment and Prevention of Pulmonary Arterial Hypertension

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhifeng Xue ◽  
Yixuan Li ◽  
Mengen Zhou ◽  
Zhidong Liu ◽  
Guanwei Fan ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Herbal Medicine ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Premature Death ◽  
Right Heart Failure ◽  
Tanshinone Iia ◽  
Active Components ◽  
Traditional Herbal Medicine ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is characterized by pulmonary artery remodeling that may subsequently culminate in right heart failure and premature death. Although there are currently both non-pharmacological (lung transplantation, etc.) and pharmacological (Sildenafil, Bosentan, and new oral drugs on trial) therapies available, PAH remains a serious and fatal pulmonary disease. As a unique medical treatment, traditional herbal medicine (THM) treatment has gradually exerted its advantages in treating PAH worldwide through a multi-level and multi-target approach. Additionally, the potential mechanisms of THM were deciphered, including suppression of proliferation and apoptosis of pulmonary artery smooth muscle cells, controlling the processes of inflammation and oxidative stress, and regulating vasoconstriction and ion channels. In this review, the effects and mechanisms of the frequently studied compound THM, single herbal preparations, and multiple active components from THM are comprehensively summarized, as well as their related mechanisms on several classical preclinical PAH models. It is worth mentioning that sodium tanshinone IIA sulfonate sodium and tetramethylpyrazine are under clinical trials and are considered the most promoting medicines for PAH treatment. Last, reverse pharmacology, a strategy to discover THM or THM-derived components, has also been proposed here for PAH. This review discusses the current state of THM, their working mechanisms against PAH, and prospects of reverse pharmacology, which are expected to facilitate the natural anti-PAH medicine discovery and development and its bench-to-bedside transformation.

scholarly journals Targeting HIF2α-ARNT hetero-dimerisation as a novel therapeutic strategy for Pulmonary Arterial Hypertension

2020 ◽  
pp. 1902061
Author(s):  
David Macias ◽  
Stephen Moore ◽  
Alexi Crosby ◽  
Mark Southwood ◽  
Xinlin Du ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Target Genes ◽  
Right Heart Failure ◽  
Pulmonary Vasculature ◽  
Pulmonary Arterial ◽  
The Impact

Pulmonary Arterial Hypertension (PAH) is a destructive disease of the pulmonary vasculature often leading to right heart failure and death. Current therapeutic intervention strategies only slow disease progression. The role of aberrant HIF2α stability and function in the initiation and development of pulmonary hypertension (PH) has been an area of intense interest for nearly two decades.Here we determine the effect of a novel HIF2α inhibitor (PT2567) on PH disease initiation and progression, using two pre-clinical models of PH. Haemodynamic measurements were performed followed by collection of heart, lung and blood for pathological, gene expression and biochemical analysis. Blood outgrowth endothelial cells from IPAH patients were used to determine the impact of HIF2α-inhibition on endothelial function.Global inhibition of HIF2a reduced pulmonary vascular haemodynamics and pulmonary vascular remodelling in both su5416/hypoxia prevention and intervention models. PT2567 intervention reduced the expression of PH associated target genes in both lung and cardiac tissues and restored plasma nitrite concentration. Treatment of monocrotaline exposed rodents with PT2567 reduced the impact on cardiovascular haemodynamics and promoted a survival advantage. In vitro, loss of HIF2α signalling in human pulmonary arterial endothelial cells suppresses target genes associated with inflammation, and PT2567 reduced the hyper-proliferative phenotype and over-active arginase activity in blood outgrowth endothelial cells from IPAH patients. These data suggest that targeting HIF2α hetero-dimerisation with an orally bioavailable compound could offer a new therapeutic approach for PAH. Future studies are required to determine the role of HIF in the heterogeneous PAH population.

Percutaneous pulmonary artery denervation completely abolishes experimental pulmonary arterial hypertension in vivo

2013 ◽  
Vol 9 (2) ◽  
pp. 269-276 ◽  
Author(s):  
Shao-Liang Chen ◽  
Yao-Jun Zhang ◽  
Lin Zhou ◽  
Du-Jiang Xie ◽  
Feng-Fu Zhang ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Pulmonary Arterial

scholarly journals Pulmonary Pulse Wave Transit Time is Associated with Right Ventricular–Pulmonary Artery Coupling in Pulmonary Arterial Hypertension

2016 ◽  
Vol 6 (4) ◽  
pp. 576-585 ◽  
Author(s):  
Kurt W. Prins ◽  
E. Kenneth Weir ◽  
Stephen L. Archer ◽  
Jeremy Markowitz ◽  
Lauren Rose ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Right Ventricular ◽  
Transit Time ◽  
Pulse Wave ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Disease ◽  
Pulse Wave Transit Time ◽  
Pulmonary Arterial

Pulmonary pulse wave transit time (pPTT), defined as the time for the systolic pressure pulse wave to travel from the pulmonary valve to the pulmonary veins, has been reported to be reduced in pulmonary arterial hypertension (PAH); however, the underlying mechanism of reduced pPTT is unknown. Here, we investigate the hypothesis that abbreviated pPTT in PAH results from impaired right ventricular–pulmonary artery (RV-PA) coupling. We quantified pPTT using pulsed-wave Doppler ultrasound from 10 healthy age- and sex-matched controls and 36 patients with PAH. pPTT was reduced in patients with PAH compared with controls. Univariate analysis revealed the following significant predictors of reduced pPTT: age, right ventricular fractional area change (RV FAC), tricuspid annular plane excursion (TAPSE), pulmonary arterial pressures (PAP), diastolic pulmonary gradient, transpulmonary gradient, pulmonary vascular resistance, and RV-PA coupling (defined as RV FAC/mean PAP or TAPSE/mean PAP). Although the correlations between pPTT and invasive markers of pulmonary vascular disease were modest, RV FAC ( r = 0.64, P < 0.0001), TAPSE ( r = 0.67, P < 0.0001), and RV-PA coupling (RV FAC/mean PAP: r = 0.72, P < 0.0001; TAPSE/mean PAP: r = 0.74, P < 0.0001) had the strongest relationships with pPTT. On multivariable analysis, only RV FAC, TAPSE, and RV-PA coupling were independent predictors of pPTT. We conclude that shortening of pPTT in patients with PAH results from altered RV-PA coupling, probably occurring as a result of reduced pulmonary arterial compliance. Thus, pPTT allows noninvasive determination of the status of both the pulmonary vasculature and the response of the RV in patients with PAH, thereby allowing monitoring of disease progression and regression.

scholarly journals Chronic thromboembolic pulmonary hypertension: a distinct disease entity

2015 ◽  
Vol 24 (136) ◽  
pp. 246-252 ◽  
Author(s):  
Irene Lang
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Right Heart Failure ◽  
Pulmonary Vasculature ◽  
Distinct Disease ◽  
Thromboembolic Pulmonary Hypertension ◽  
Perfusion Scan ◽  
Pulmonary Arterial

Chronic thromboembolic pulmonary hypertension (CTEPH) is a distinct subtype of pulmonary hypertension (PH). One disease hypothesis is that CTEPH results from the non-resolution of venous thromboembolism. CTEPH is characterised by the presence of obstructive fibrotic thromboembolic material in the major pulmonary vessels, with concomitant microvascular arteriopathy, resulting in progressive PH. The clinical presentation of CTEPH is similar to pulmonary arterial hypertension with nonspecific symptoms, but it is distinguished from pulmonary arterial hypertension by the presence of mismatched segmental defects on the ventilation/perfusion scan. The exact prevalence and incidence of CTEPH are unknown, but are thought to have been underestimated in the past. CTEPH is unique among the subgroups of PH in that it is potentially curable with pulmonary endarterectomy, a surgical intervention intended to remove the occlusive material from the pulmonary vasculature. However, in some patients the obstructions are technically inaccessible or the risk/benefit ratios are unfavourable, making the condition inoperable. It is thought that the involvement of the smaller, more distal vessels is a target for medical treatment. Untreated, CTEPH may result in right heart failure and death. The pathophysiological mechanisms which cause CTEPH are complex and have not yet been fully elucidated.

scholarly journals Abnormal Pulmonary Artery Stiffness in Pulmonary Arterial Hypertension: In Vivo Study with Intravascular Ultrasound

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33331 ◽  
Author(s):  
Edmund M. T. Lau ◽  
Nithin Iyer ◽  
Rahn Ilsar ◽  
Brian P. Bailey ◽  
Mark R. Adams ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Intravascular Ultrasound ◽  
In Vivo Study ◽  
Artery Stiffness ◽  
Pulmonary Arterial

scholarly journals EXPRESS: Platelets, extracellular vesicles & coagulation in pulmonary arterial hypertension

2021 ◽  
pp. 204589402110210
Author(s):  
Sarah Cullivan ◽  
Claire A Murphy ◽  
Luisa Weiss ◽  
Shane P Comer ◽  
Barry Kevane ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Therapeutic Interventions ◽  
Pulmonary Vasculature ◽  
Future Research ◽  
Regulatory Pathways ◽  
Paracrine Signalling ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a rare disease of the pulmonary vasculature, characterised pathologically by proliferation, remodelling and thrombosis in situ. Unfortunately, existing therapeutic interventions do not reverse these findings and the disease continues to result in significant morbidity and premature mortality. A number of haematological derangements have been described in PAH which may provide insights into the pathobiology of the disease and also provide opportunities to target new therapeutic pathways. These include quantitative and qualitative platelet abnormalities, such as thrombocytopaenia, increased mean platelet volume (MPV) and altered platelet bioenergetics. Furthermore, a hypercoagulable state and aberrant negative regulatory pathways can be observed, which could contribute to thrombosis in situ in distal pulmonary arteries and arterioles. Finally, there is increasing interest in the role of extracellular vesicle (EV) autocrine and paracrine signalling in PAH, and their potential utility as biomarkers and novel therapeutic targets. This review focuses on the potential role of platelets, EVs and coagulation pathways in the pathobiology of PAH. We highlight important unanswered clinical questions and the implications of these observations for future research and PAH directed therapies.

scholarly journals Echocardiography in Pulmonary Arterial Hypertension: Is It Time to Reconsider Its Prognostic Utility?

2021 ◽  
Vol 10 (13) ◽  
pp. 2826
Author(s):  
Ioannis T. Farmakis ◽  
Eftychia Demerouti ◽  
Panagiotis Karyofyllis ◽  
George Karatasakis ◽  
Maria Stratinaki ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Right Heart Failure ◽  
Pulmonary Vasculature ◽  
Right Heart ◽  
Prognostic Utility ◽  
Pulmonary Arterial ◽  
Prognostic Implications ◽  
The Right

Pulmonary arterial hypertension (PAH) is characterized by an insult in the pulmonary vasculature, with subsequent right ventricular (RV) adaptation to the increased afterload that ultimately leads to RV failure. The awareness of the importance of RV function in PAH has increased considerably because right heart failure is the predominant cause of death in PAH patients. Given its wide availability and reduced cost, echocardiography is of paramount importance in the evaluation of the right heart in PAH. Several echocardiographic parameters have been shown to have prognostic implications in PAH; however, the role of echocardiography in the risk assessment of the PAH patient is limited under the current guidelines. This review discusses the echocardiographic evaluation of the RV in PAH and during therapy, and its prognostic implications, as well as the potential significant role of repeated echocardiographic assessment in the follow-up of patients with PAH.

scholarly journals Pulmonary Arterial Hypertension: Molecular Genetic Basis and Emerging Treatments

2012 ◽  
Vol 3 (2) ◽  
pp. 30-33
Author(s):  
MA Siddiqui ◽  
Takeshi Ogo ◽  
MT Nasim
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Genetic Basis ◽  
Molecular Genetic ◽  
Right Heart Failure ◽  
Cardiovascular Disorder ◽  
Therapeutic Interventions ◽  
Genetic Components ◽  
Molecular Genetic Basis ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a rare cardiovascular disorder caused by narrowing of blood vessels in the lung and in the absence of therapy leads to right heart failure and death. No cure for this devastating disorder is known. The major objective of the current treatments is to improve symptoms and these therapies were developed prior to the discovery that this disease has substantial genetic components. In this review, we discuss molecular      genetic basis of PAH together with pathobiology, current and future therapeutic interventions.   DOI: http://dx.doi.org/10.3329/akmmcj.v3i2.11691   AKMMC J 2012; 3(2): 30-33  

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.

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