Abstract 16770: The Epigenetic Modifier EP300: A New Corner Stone in the Regulation of Both Vascular Remodeling and Right Ventricle Failure in Pulmonary Arterial Hypertension

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Alice Bourgeois ◽  
Sarah-Eve Lemay ◽  
Yann Grobs ◽  
Charlotte romanet ◽  
Junichi Omura ◽  
...  

Introduction: Pulmonary Arterial Hypertension (PAH) is characterized by excessive proliferation and resistance to apoptosis of pulmonary artery (PA) smooth muscle cells (PASMCs), leading to progressive increases in pulmonary vascular resistance, and ultimately right ventricular (RV) failure and death. Thanks to omics technologies, we made tremendous progress in understanding gene misregulation during disease processes and identified the epigenetic factor EP300 as a critical player in pathological processes like proliferation/apoptosis and hypertrophy/fibrosis all of which are critical features of both PA remodeling and RV failure in PAH. We hypothesized that EP300 is upregulated in PAH and contributes to both PA remodeling and RV failure. Methods and Results: By Western blot (WB) and immunofluorescence (IF), we found that EP300 is up-regulated in isolated PASMCs and distal PAs from PAH patients (n=11-14) compared to controls (n=8-10) (p<0.01). Similar results were observed in 3 PAH animal models, namely the monocrotaline (MCT), the Sugen/Hypoxia (Su/Hx) and the Fawn-Hooded rat (FHR) (p<0.05). In vitro, pharmacological inhibition of EP300 using CCS-1477 reduces PAH-PASMC proliferation (Ki67 labeling & WB PCNA; p<0.05) and resistance to apoptosis (Annexin V assay & WB Survivin; p<0.05). These effects were confirmed at the molecular level by RNA-Seq analysis. In addition, increased EP300 expression was observed in hypertrophied and failed RV from PAH patients, as well as in rats injected with MCT or subjected to pulmonary artery banding (WB, p<0.05). In animal models, EP300 negatively correlates with CO and positively correlates with RVEDP, cardiomyocyte surface area and fibrosis. Finally, we demonstrated that inhibition of EP300 using CCS-1477 or SGC-CBP30 significantly improved established PAH (right heart catheterization) in two animal models (MCT and FHR). Conclusion: EP300 upregulation contributes to both pulmonary vascular remodeling and RV dysfunction seen in PAH and its inhibition represents a promising therapeutic avenue.

2020 ◽  
Vol 10 (4) ◽  
pp. 204589402097491
Author(s):  
Zhenhua Wu ◽  
Jie Geng ◽  
Yujuan Qi ◽  
Jian Li ◽  
Yaobang Bai ◽  
...  

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.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Kazimierczyk ◽  
L A Malek ◽  
P Szumowski ◽  
P Blaszczak ◽  
D Jurgilewicz ◽  
...  

Abstract Background The concept of coupling mainly refers to the relationship between ventricular contractility and afterload. Together, strictly related parameters may provide a more accurate estimation of the RV performance status. Indexing RV function, assessed by CMR feature tracking analysis, with a pulmonary artery systolic pressure (PASP) obtained from right heart catheterization (RHC) allows estimation of ventricular-arterial coupling and could help in prognostic stratification of pulmonary arterial hypertension (PAH) patients. Aim To verify the prognostic value of multimodal approach to estimate RV ventricular-arterial coupling in PAH patients. Methods Twenty-six stable PAH patients (mean age 49.92±15.94 years) and twelve healthy subjects (control group, 44.75±13.51 years) were enrolled into the study. CMR feature tracking analysis of the RV was performed for generation of RV global longitudinal strain (RV GLS); RV ejection fraction was also obtained by CMR. Right heart catheterization was carried out only in the PAH group with a standard technique.RV- arterial coupling was evaluated by the ratio of RV GLS/PASP. Mean follow-up time of this study was 16.6±7.5 months and the clinical end-point (CEP) was defined as death or clinical deterioration. Results In study group, RV GLS significantly correlated with hemodynamic parameters from RHC – mean pulmonary artery pressure, mPAP (r=0.53, p=0.04) and pulmonary vascular resistance, PVR (r=0.57, p=0.002). Mean RV GLS/PASP ratio in PAH group was (−)0.24±0.15%/mmHg. Patients who reached CEP (n=15) had a significantly higher RV GLS and RV GLS/PASP ratio (−13.3±7.9% vs −20.4±6.2%, p=0.01 and −0.15±0.09%/mmHg vs −0.36±0.19%/mmHg, p=0.005, respectively). However, ROC analysis revealed higher area under curve (AUC) of RV GLS/PASP in predicting CEP than of RV GLS alone (0.82 (95% CI 0.64–1) vs 0.77 (95% CI 0.58–0.96), p<0.0001). Interestingly, at univariate analysis only RV GLS/PASP (HR: 0.89; 95% CI: 0.79–1.08; p=0.03), together with mPAP were all significantly associated with CEP. Patients with RV GLS/PASP cut-off value (ROC analysis) higher than (−)0.29%/mmHg had worse prognosis, log-rank test, p=0.01 (Figure 1). Figure 1 Conclusions Combining CMR and hemodynamic measurements via catheterization offers the potential for more comprehensive assessment of pulmonary vascular load and right heart function, as required for evaluation of the hemodynamic state in patients with PAH. Acknowledgement/Funding This work was supported by National Center for Science in Poland [“Preludium” grant 2017/25/N/NZ5/02689 to R.K.]


2016 ◽  
Vol 30 (2) ◽  
pp. 48-52 ◽  
Author(s):  
Abrar Kaiser ◽  
Fazilatunnessa Malik ◽  
Tuhin Haque ◽  
Iftekhar Alam ◽  
Abdullah Al Masud ◽  
...  

Background: Pulmonary arterial hypertension (PAH) is a severe disease characterized by a progressive increase of pulmonary pressure and resistance leading to right heart failure. Pulmonary arterial hypertension is commonly diagnosed at a late stage of the disease and is associated with progressive clinical deterioration and premature death. The assessment of pulmonary artery pressure is important in clinical management and prognostic evaluation of patients with cardiovascular and pulmonary disease. Although PH can be detected invasively by right ventricular (RV) catheterization, accurate non-invasive assessment by echocardiography has many advantages. Reliable non-invasive evaluation of pulmonary pressure at present is still a problem as echocardiographic measurement of pulmonary hypertension relies on the presence of tricuspid regurgitation (TR). Objective: The purpose of this study was to determine whether right ventricular end diastolic diameter can predict the presence of pulmonary hypertension. Methods: Eighty consecutive patients with echo detectable tricuspid regurgitation who underwent right heart catheterization for either diagnostic or therapeutic procedure were recruited. They were divided into two groups on the basis of pulmonary artery systolic pressure (PASP). Group I consists of 40 patients with PASP >35 mm Hg and Group II 40 patients having PASP d• 35 mm Hg. Right ventricular end-diastolic diameter (RVD) was measured in the apical 4 chamber view. PASP was measured from right heart catheterization. Results: The RVD has strong correlation with catheter-derived PASP, at a cutoff value of >3 cm, predicted the presence of PAH with 78% sensitivity and 71% specificity. Conclusion: RVD is a good non-invasive predictor for PAH. RVD can predict the presence of PAH even in absence of TR and correlates well with PASP measured by RV catheterization.Bangladesh Heart Journal 2015; 30(2) : 48-52


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1063.2-1063
Author(s):  
J. Wang ◽  
Y. Feng ◽  
Y. Lei ◽  
X. Zhang

Background:Based on the characteristics of systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH), Sunet alhas put forward a scoring system to distinguish two clinical phenotypes as vasculitic and vasculopathic subtypes[1]. A weighted score ≥2 suggested a vasculitic subtype by combining two factors: The time interval between SLE and PAH diagnosis <2 years and ≥2 years were 1 and 0 point; SLE Disease Activity Index (SLEDAI) >9, 5-9 and <5 were 2, 1, 0 point, respectively. While the vasculitic subtype seemed to have poorer prognosis in Sun’s research, other study has shown controversial result[2].Objectives:To find out the prognosis of two distinct clinical phenotypes of SLE-PAH.Methods:Between 2008 and 2019, a SLE-PAH cohort confirmed by right heart catheterization (RHC) from Guangdong Provincial People’s Hospital was included. Other groups of pulmonary hypertension were excluded. Based on the scoring system, patients were divided into vasculitic (weighted score≥2) and vasculopathic subtypes (weighted score<2). The endpoint was PAH-related mortality. Survival status were confirmed by clinic follow-up data or phone call.Results:A total of 53 SLE-PAH patients were enrolled. The cases of vasculitic and vasculopathic subtype were 14 and 39, respectively. Ten endpoint events occurred. Eight attributed to PAH and the cause could not be traced in two which were still included in study. The pooled 1-, 3-, 5-year survival rates were 85.7%, 78.6%, 65.5% in vasculitic subtype, and 93.9%, 87.5%, 87.5% in vasculopathic subtype, respectively. Kaplan-Meier analysis showed vasculitic subtype tended to have a poorer prognosis than vasculopathic subtype (p=0.16, HR 2.4, 95%CI 0.5-13.8, figure 1).Figure 1.Survival curves for patients with systemic lupus erythematosus-pulmonary arterial hypertension (SLE-PAH) in two distinct subtypes. RHC, Right Heart Catheterization.Conclusion:The prognosis of the two phenotypes of SLE-PAH was statistically indifferent while the vasculitic subtype showed a trend of worse prognosis. Further studies are needed.References:[1]F. Sun, Y. Lei, W. Wu, L. Guo, K. Wang, Z. Chen, W. Xu, X. Wang, T. Li, X. Zhang, S. Ye, Two distinct clinical phenotypes of pulmonary arterial hypertension secondary to systemic lupus erythematosus, Ann Rheum Dis 78(1) (2019) 148-150.[2]J. Qian, M. Li, J. Zhao, Q. Wang, Z. Tian, X. Zeng, Inflammation in SLE-PAH: good news or not?, Ann Rheum Dis (2018).0:1–2. doi:10.1136/annrheumdis-2018-214605Disclosure of Interests:None declared


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Oliver ◽  
S.F Rocha ◽  
M Spaczynska ◽  
D.V Lalama ◽  
M Gomez ◽  
...  

Abstract Background Endothelial dysfunction is one of the most important hallmarks of pulmonary arterial hypertension (PAH). This leads to anomalous production of vasoactive mediators that are responsible for a higher vascular tone and a subsequent increase in pulmonary artery pressure (PAP), and to an increased vascular permeability that favors perivascular inflammation and remodeling, thus worsening the disease. Therefore, preservation of the endothelial barrier could become a relevant therapeutic strategy. Purpose In previous studies, others and we have suggested the pharmacological activation of the β3-adrenergic receptor (AR) as a potential therapeutic strategy for pulmonary hypertension (PH) due to left heart disease. However, its potential use in other forms of PH remain unclear. The aim of the present study was to elucidate whether the β3-AR agonist mirabegron could preserve pulmonary endothelium function and be a potential new therapy in PAH. Methods For this purpose, we have evaluated the effect of mirabegron (2 and 10 mg/kg·day) in different animal models, including the monocrotaline and the hypoxia-induced PAH models in rats and mice, respectively. Additionally, we have used a transgenic mouse model with endothelial overexpression of human β3-AR in a knockout background, and performed in vitro experiments with human pulmonary artery endothelial cells (HPAECs) for mechanistic experiments. Results Our results show a dose dependent effect of mirabegron in reducing mean PAP and Right Ventricular Systolic Pressure in both mice and rats. In addition, the use of transgenic mice has allowed us to determine that pulmonary endothelial cells are key mediators of the beneficial role of β3-AR pathway in ameliorating PAH. Mechanistically, we have shown in vitro that activation of β3-AR with mirabegron protects HPAECs from hypoxia-induced ROS production and mitochondrial fragmentation by restoring mitochondrial fission/fusion dynamics. Conclusions This protective effect of mirabegron would lead to endothelium integrity and preserved pulmonary endothelial function, which are necessary for a correct vasodilation, avoiding increased permeability and remodeling. Altogether, the current study demonstrates a beneficial effect of the β3-AR agonist mirabegron that could open new therapeutic avenues in PAH. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Programa de Atracciόn de Talento, Comunidad de Madrid


2016 ◽  
Vol 64 (4) ◽  
pp. 969.1-969 ◽  
Author(s):  
JR Sysol ◽  
J Chen ◽  
S Singla ◽  
V Natarajan ◽  
RF Machado ◽  
...  

RationalePulmonary arterial hypertension (PAH) is a severe, progressive disease characterized by increased pulmonary arterial pressure and resistance due in part to uncontrolled vascular remodeling. The mechanisms contributing to vascular remodeling in PAH are poorly understood and involve rampant pulmonary artery smooth muscle cell (PASMC) proliferation. We recently demonstrated the important role of sphingosine kinase 1 (SphK1), a lipid kinase producing pro-proliferative sphingosine-1-phosphate (S1P), in the development of pulmonary vascular remodeling in PAH. However, the regulatory processes involved in upregulation of SphK1 in this disease are unknown.ObjectiveIn this study, we aimed to identify novel molecular mechanisms governing the regulation of SphK1 expression, with a focus on microRNA (miR). Using both in vitro studies in pulmonary artery smooth muscle cells (PASMCs) and an in vivo mouse model of experimental hypoxia-mediated pulmonary hypertension (HPH), we explored the role of miR in controlling SphK1 expression in the development of pulmonary vascular remodeling.Methods and ResultsIn silico analysis identified hsa-miR-1-3p (miR-1) as a candidate targeting SphK1. We demonstrate miR-1 is down-regulated by hypoxia in human PASMCs and in lung tissues of mice with HPH, coinciding with upregulation of SphK1 expression. PASMCs isolated from patients with PAH had significantly reduced expression of miR-1. Transfection of human PASMCs with miR-1 mimics significantly attenuated activity of a SphK1-3'-UTR luciferase reporter construct and SphK1 protein expression. miR-1 overexpression in human PASMCs also inhibited proliferation and migration under normoxic and hypoxic conditions, both important in pathogenic vascular remodeling in PAH. Finally, we demonstrated that intravenous administration of miR-1 mimics prevents the development of experimental HPH in mice and attenuates induction of SphK1 in PASMCs.ConclusionThese data demonstrate that miR-1 expression in reduced in PASMCs from PAH patients, is modulated by hypoxia, and regulates the expression of SphK1. Key phenotypic aspects of vascular remodeling are influenced by miR-1 and its overexpression can prevent the development of HPH in mice. These studies further our understanding of the mechanisms underlying pathogenic pulmonary vascular remodeling in PAH and could lead to novel therapeutic targets.Supported by grants NIH/NHLBI R01 HL127342 and R01 HL111656 to RFM, NIH/NHLBI P01 HL98050 and R01 HL127342 to VN, American Heart Association Predoctoral Fellowship (15PRE2190004) to JRS, and NIH/NLHBI NRSA F30 Fellowship (FHL128034A) to JRS.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Eileen M Harder ◽  
Pietro Nardelli ◽  
Gonzalo Sanchez-Ferrero ◽  
James Ross ◽  
Sam Y Ash ◽  
...  

Introduction: Increased vascular tortuosity has been proposed as a marker of pulmonary arterial hypertension (PAH). In this analysis, we compared arterial and venous vascular tortuosity between controls and subjects with resting PAH. Furthermore, we examined if abnormalities could be detected in exercise PAH (EPAH), thought to be an early form of PAH. Methods: From an institutional registry, 388 patients with both right heart catheterization and computed tomography angiography (CTA) data were selected. Within this cohort, three distinct groups were identified: 1) controls, who had no cardiopulmonary disease and normal resting and exercise hemodynamics; 2) EPAH, with normal resting hemodynamics but age-adjusted pre-capillary pulmonary hypertension on exertion, and 3) PAH, defined as resting mPAP >20mmHg, pulmonary vascular resistance >3 Wood Units, and pulmonary capillary wedge pressure <15mmHg. Tortuosity was defined as the actual path length of a vessel divided by the linear distance between the two farthest endpoints of the vessel segment on CTA. AV>10% was defined as the number of arterial segments with tortuosity >10% divided by the same venous measure. Analysis was performed with Wilcoxon rank sum tests in R 3.5. Results: There were 99 patients in the final cohort, including 47 (47.4%) with PAH, 12 (12.1%) with EPAH, and 40 (40.4%) without disease. Compared to controls, median arterial tortuosity was increased in PAH (3.3 ± 0.1% vs. 3.4 ± 0.1%, p=0.0009; Figure 1) but not in EPAH (3.3 ± 0.1%, p=0.82). Median venous tortuosity did not differ between groups. AV>10% was increased in EPAH (vs. controls, 1.86 ± 0.38 vs. 1.56 ± 0.44, p=0.03) and resting PAH (2.0 ± 1.2 p=2e-6). Conclusions: Increased arterial tortuosity on CTA is a biomarker of resting PAH. When corrected for venous tortuosity, arterial tortuosity also appears to be abnormal in EPAH. Figure 1 . Arterial vessels in PAH, EPAH, and control subjects. Red segments have tortuosity > 10%.


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