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Introduction: Pulmonary hypertension (PH) is often complicated by chronic lung diseases (CLDs) such as chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Differentiating between PH associated with CLD (group 3 PH) and pulmonary arterial hypertension (PAH) in CLD is often difficult and reporting on the efficacy of PAH-specific therapies is inconsistent as a result of the lack of understanding of the heterogeneity of patients with PH. Methods: A retrospective observational cohort study was conducted to understand the baseline characteristics, comorbidities, and treatment profiles of patients with PH in CLD in a real-world setting using a large-scale claims database (Medical Data Vision). Administrative and clinical data for patients admitted to acute-care hospitals in Japan between April 2008 and January 2021 were analyzed. Results: A total of 115,921 patients with CLD (109,578 with COPD and 6343 with ILD, of whom 569 and 176 had PH, respectively) were analyzed. This study found lower PH diagnosis rates among patients with COPD and patients with ILD than in previous studies. The majority of PH with CLD patients were elderly (mean age 75.7 years) and male (80.81%). Among patients with CLD prescribed PAH-specific therapies (105 patients with COPD; 64 patients with ILD), most received these as monotherapy (COPD, 84.76%; ILD, 75.56%); the most common were phosphodiesterase 5 inhibitors (COPD, 42.70%; ILD, 18.37%), prostacyclins (oral; COPD, 48.31%; ILD, 24.49%), and endothelin receptor antagonists (ERA) (COPD, 8.99%; ILD, 18.37%). Comorbidities (e.g., pulmonary, cardiac, kidney), home oxygen therapy (HOT), and echocardiography (ECHO) were factors associated with the diagnosis of PH. Conclusion: This is the first study using an administrative database that provides real-world data on patients with PH in CLD in Japan. Our results indicate that PH may be misdiagnosed or underdiagnosed in Japan which may lead to suboptimal treatment for patients, and supports the need for further evidence to guide appropriate treatment. Plain Language Summary: Pulmonary hypertension is a disorder affecting the arteries in the lungs and the right heart. It can be associated with a variety of heart and lung conditions, including many chronic lung diseases such as chronic obstructive pulmonary disease and interstitial lung disease. Patients with pulmonary hypertension with chronic lung disease and/or hypoxia can be hard to tell apart from patients with pulmonary arterial hypertension coinciding with chronic lung disease. In Japan, there is not enough data on patient demographics and their disease characteristics for patients with pulmonary hypertension and chronic lung disease, including treatment profiles, and disease management. We identified these patients from a large medical claims database in Japan and analyzed their data. Our study focused on the use of therapies for pulmonary arterial hypertension on patients with pulmonary hypertension and chronic lung disease. The diagnosis rates of pulmonary hypertension for patients with chronic obstructive pulmonary disease and interstitial lung disease were low compared to previous reports, meaning patients with pulmonary hypertension may be misdiagnosed or underdiagnosed which may be resulting in suboptimal treatments. Furthermore, the majority of patients with pulmonary hypertension treated with pulmonary arterial hypertension medication received a single drug as treatment, even though the guidelines recommend the use of combination therapies in certain situations. This study emphasizes the need for further evidence generation for improvements in diagnoses and treatment of patients with pulmonary hypertension in Japan. [ABSTRACT FROM AUTHOR]

Introduction: Real-world data on the comparative effectiveness of endothelin receptor antagonists (ERAs; macitentan, bosentan, ambrisentan) for pulmonary arterial hypertension (PAH), particularly in Asian countries, are scarce. We evaluated the persistence of these ERAs before and after macitentan approval in Japan (2015). Methods: We used real-world data from the Japanese Medical Data Vision administrative claims database between April 2008 and November 2020. Patients with PAH were identified from the dataset. Persistence to ERA treatment before and after approval of macitentan in Japan was defined as the time between start of the index ERA and treatment discontinuation or death. Propensity score adjustment was applied to minimize confounding effects among treatment groups. Results: In the pre-macitentan approval cohort, 153 and 51 patients received bosentan and ambrisentan, respectively. In the post-macitentan approval cohort, 331, 284, and 91 patients received macitentan, bosentan, and ambrisentan, respectively. Unadjusted median persistence for ambrisentan- and bosentan-treated patients was 19 and 10 months, respectively (adjusted HR 0.87 [95% CI 0.61–1.24]; P = 0.434 [bosentan as reference]). In the post-macitentan approval cohort, unadjusted median persistence was 18 months for macitentan-treated patients versus 6 and 8 months for ambrisentan- and bosentan-treated patients, respectively. Adjusted HRs for ambrisentan and bosentan were 1.48 (95% CI 1.12–1.95; P = 0.006) and 1.63 (95% CI 1.30–2.04; P < 0.001 [macitentan as reference]), respectively. Conclusions: Real-world data for Japanese patients with PAH showed that persistence was significantly higher for macitentan, versus ambrisentan and bosentan, since its approval. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Patient and Therapeutic Profiles of Pulmonary Hypertension in Chronic Lung Diseases in Japan: A Cohort Study Using a Claims Database." The original article contained a mistake in the alignment of the heading in Table 3. The corrected table is provided in the correction notice. The article discusses the CCI and NHYA classes of the PAH therapy group and the no treatment group in relation to COPD and ILD. The authors of the article are Kazuki Kitahara, Junichi Omura, Shingo Wada, and Seok-Won Kim. [Extracted from the article]

Background: Right ventricular (RV) function is the major determinant for both functional capacity and survival in patients with pulmonary arterial hypertension (PAH). Despite the recognized clinical importance of preserving RV function, the subcellular mechanisms that govern the transition from a compensated to a decompensated state remain poorly understood and as a consequence there are no clinically established treatments for RV failure and a paucity of clinically useful biomarkers. Accumulating evidence indicates that long noncoding RNAs are powerful regulators of cardiac development and disease. Nonetheless, their implication in adverse RV remodeling in PAH is unknown.Methods: Expression of the long noncoding RNA H19 was assessed by quantitative PCR in plasma and RV from patients categorized as control RV, compensated RV or decompensated RV based on clinical history and cardiac index. The impact of H19 suppression using GapmeR was explored in 2 rat models mimicking RV failure, namely the monocrotaline and pulmonary artery banding. Echocardiographic, hemodynamic, histological, and biochemical analyses were conducted. In vitro gain- and loss-of-function experiments were performed in rat cardiomyocytes.Results: We demonstrated that H19 is upregulated in decompensated RV from PAH patients and correlates with RV hypertrophy and fibrosis. Similar findings were observed in monocrotaline and pulmonary artery banding rats. We found that silencing H19 limits pathological RV hypertrophy, fibrosis and capillary rarefaction, thus preserving RV function in monocrotaline and pulmonary artery banding rats without affecting pulmonary vascular remodeling. This cardioprotective effect was accompanied by E2F transcription factor 1-mediated upregulation of enhancer of zeste homolog 2. In vitro, knockdown of H19 suppressed cardiomyocyte hypertrophy induced by phenylephrine, while its overexpression has the opposite effect. Finally, we demonstrated that circulating H19 levels in plasma discriminate PAH patients from controls, correlate with RV function and predict long-term survival in 2 independent idiopathic PAH cohorts. Moreover, H19 levels delineate subgroups of patients with differentiated prognosis when combined with the NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels or the risk score proposed by both REVEAL (Registry to Evaluate Early and Long-Term PAH Disease Management) and the 2015 European Pulmonary Hypertension Guidelines.Conclusions: Our findings identify H19 as a new therapeutic target to impede the development of maladaptive RV remodeling and a promising biomarker of PAH severity and prognosis. [ABSTRACT FROM AUTHOR]

Abstract Pulmonary arterial hypertension (PAH) encompasses a group of clinical entities characterized by sustained vasoconstriction and progressive vascular remodeling that act in concert to elevate pulmonary vascular resistance. The current treatments for PAH are mainly dedicated to target the process of vasoconstriction and do not offer a cure. There is now accumulating evidence that expansion of pulmonary artery cells due to increased proliferation and apoptotic evasion is a key pathological component of vascular remodeling that occurs in PAH. Thus, vascular lesions seen in advanced PAH patients present some cancer-like characteristics offering important avenues for exploration and expanding treatment options. In this review article, we will discuss recent advances into mechanisms underlying disease progression, with a focus on pulmonary artery smooth muscle cells. [ABSTRACT FROM AUTHOR]

Introduction: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018.Study Objective: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018.Methods: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018.Results: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018.Conclusion: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018.Trial Registration: The pathogenesis and clinical profiles of patients with pulmonary hypertension (PH) associated with interstitial lung disease (ILD-PH) are poorly understood. Whether and to what extent pulmonary arterial hypertension (PAH)-specific therapy improves hemodynamic and outcome in ILD-PH are also unknown.This study aims to clarify the characteristics, clinical course and response to PAH-specific therapy of ILD and/or PH by enrolling three unique subsets: PAH, ILD-PH, and ILD.The proposed study is a retrospective and prospective, multi-centre, observational cohort study of patients treated at any of three university hospitals in the Hokkaido region of Japan who have any one of the following: PAH; ILD-PH with or without PAH features; or ILD without PH. We aim to enrol 250 patients in total. For the retrospective observation period, data obtained after 1 January 2010, will be analysed, and the prospective observation period will be 1 year. We will compare the clinical data of patients with ILD-PH with those of patients with PAH and those of patients with ILD without PH in the real-world clinical setting. In addition, within the cohort of patients with ILD-PH, we will explore the subset with “ILD-PH with PAH features” and compare the response to PAH-specific therapy with that of PAH. The primary outcome will be the change in pulmonary vascular resistance from first treatment to follow-up in patients with PAH and ILD-PH with PAH features (excluding ILD-PH without PAH feature and ILD-no-PH for the primary outcome). The exploratory outcomes will include analyses of PH-associated biomarkers, right ventricular function and patient-reported outcomes.This is a protocol article and the results will be presented after data collection is completed.The POPLAR study will provide data that help better understand the pathophysiology of ILD-PH and improve the quality of life and outcome of patients with PH and/or ILD.Japan Registry of Clinical Trials: jRCT1010230018. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by a sustained elevation of pulmonary artery (PA) pressure, right ventricular failure, and premature death. Enhanced proliferation and resistance to apoptosis (as seen in cancer cells) of PA smooth muscle cells (PASMCs) is a major pathological hallmark contributing to pulmonary vascular remodeling in PAH, for which current therapies have only limited effects. Emerging evidence points toward a critical role for Enhancer of Zeste Homolog 2 (EZH2) in cancer cell proliferation and survival. However, its role in PAH remains largely unknown. The aim of this study was to determine whether EZH2 represents a new factor critically involved in the abnormal phenotype of PAH-PASMCs. We found that EZH2 is overexpressed in human lung tissues and isolated PASMCs from PAH patients compared to controls as well as in two animal models mimicking the disease. Through loss- and gain-of-function approaches, we showed that EZH2 promotes PAH-PASMC proliferation and survival. By combining quantitative transcriptomic and proteomic approaches in PAH-PASMCs subjected or not to EZH2 knockdown, we found that inhibition of EZH2 downregulates many factors involved in cell-cycle progression, including E2F targets, and contributes to maintain energy production. Notably, we found that EZH2 promotes expression of several nuclear-encoded components of the mitochondrial translation machinery and tricarboxylic acid cycle genes. Overall, this study provides evidence that, by overexpressing EZH2, PAH-PASMCs remove the physiological breaks that normally restrain their proliferation and susceptibility to apoptosis and suggests that EZH2 or downstream factors may serve as therapeutic targets to combat pulmonary vascular remodeling. [ABSTRACT FROM AUTHOR]

Although pulmonary hypertension (PH) and Eisenmenger's syndrome (ES) are common complications in adult congenital heart disease (ACHD), the frequency of diagnostic tests and the incidence of PH/ES in patients with ACHD in Japanese clinical practice are unclear. Therefore, we sought to clarify the frequency of diagnostic tests and incidence of PH/ES in patients with ACHD using the Medical Data Vision (MDV) database, the largest anonymized database of diagnosis procedure combination hospitals in Japan. We conducted a retrospective cohort study using the MDV database (April 2008 to December 2021) of patients with ACHD (International Classificaiton of Diseases, 10th revision codes: Q203-204, Q210-213, Q250) aged ≥15 years. The frequency of laboratory/clinical tests and the incidence of PH/ES were calculated. Subgroup analyses were performed for the periods 2008–2015 and 2016–2021. Overall, 28219 ACHD patients were extracted from the MDV database (females 56.3%, males 43.7%; mean ± standard deviation age 44.7 ± 23.5 years). The mean ± standard deviation follow-up period was 2.5 ± 2.7 years. The frequencies of electrocardiography, ultrasonography, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP), right heart catheterization, and pulmonary function tests (DLCO) were 2149.8, 1054, 1233, 340, 40.0, and 6.0 per 1000 person-years, respectively. The incidence rate of PH/ES was 32.8 per 1000 person-years. The incidence rate of PH/ES increased from 24.6 to 46.7 per 1000 person-years from 2008–2015 to 2016–2021. We have clarified the frequency of diagnostic tests related to PH/ES and the incidence of PH/ES in patients with ACHD in clinical practice in Japan, including non-specialist institutions for PH. [ABSTRACT FROM AUTHOR]

Background: Right ventricular failure (RVF) is the major prognostic factor for both morbidity and mortality in pulmonary hypertension. A better understanding of the molecular mechanisms accounting for the transition from a compensated (preserve cardiac output) RV hypertrophy (CRVH) to a decompensated (decrease cardiac output) DRVH in PAH patients is needed. Recent Omics analyses have demonstrated the deregulation of several long non-coding RNAs (LncRNAs) in heart failure, but their role in RVF remains unknown. The LncRNA H19 and its encoded miR-675 are regulated by the epigenetic repressor EZH2 and have been implicated in both hypertrophy and fibrosis processes, (2 features of RVF) but never been studied in RVF. We hypothesized that H19/miR-675 up-regulation is implicated in the development of DRVH and is driven by EZH2 repression. Methods and Results: By qRT-PCR we showed in human RV biopsies obtained from control donors (n=10), CRVH patients (n=7, Cardiac index > 2.2) and DRVH patients (n=12, PAH patients died from RVF), that H19 and miR-675 were specifically upregulated (p<0.001) in DRVH. Similar findings were found in the monocrotaline rat (n≈50 p<0.05). Interestingly H19/miR-675 up-regulation was RV specific as no change was seen in both LV and lung of DRVH patients and rats. In ≈70 patients, we showed that H19 plasma levels were up-regulated in PAH (p<0.001) and positively correlated with PAH severity (pulmonary vascular resistance, PA pressure, cardiac index and pro-BNP, p<0.05), this was also confirmed in rats. Mechanistically, we demonstrated that the up-regulation of H19/miR-675 is driven by the repression of EZH2 and that enhanced H19 expression is associated with reduced CamKII δ/GSK3/β-catenin signaling (p<0.05) which is implicated in hypertrophy & fibrosis. Therefore, as expected H19/miR-675 expression correlated positively with both RV fibrosis (p<0.01) and cardiomyocytes hypertrophy (p<0.05). Conclusions: We demonstrated for the first time that EZH2/H19/miR-675 axis is implicated in the transition from CRVH to DRVH in RVF by impacting both hypertrophy and fibrosis. Given its RV specificity, circulating H19 represents an attractive biomarker of RV function in PAH patients. The therapeutic value of H19 remains to be established. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Background: Thoracic aortic aneurysm (TAA) and dissection are fatal diseases that cause aortic rupture and sudden death. The small GTP-binding protein GDP dissociation stimulator (SmgGDS) is a crucial mediator of the pleiotropic effects of statins. Previous studies revealed that reduced force generation in aortic smooth muscle cells (AoSMCs) causes TAA and thoracic aortic dissection. Methods: To examine the role of SmgGDS in TAA formation, we used an angiotensin II (1000 ng·min−1·kg−1, 4 weeks)–induced TAA model. Results: We found that 33% of Apoe −/− SmgGDS +/− mice died suddenly as a result of TAA rupture, whereas there was no TAA rupture in Apoe −/− control mice. In contrast, there was no significant difference in the ratio of abdominal aortic aneurysm rupture between the 2 genotypes. We performed ultrasound imaging every week to follow up the serial changes in aortic diameters. The diameter of the ascending aorta progressively increased in Apoe −/− SmgGDS +/− mice compared with Apoe −/− mice, whereas that of the abdominal aorta remained comparable between the 2 genotypes. Histological analysis of Apoe −/− SmgGDS +/− mice showed dissections of major thoracic aorta in the early phase of angiotensin II infusion (day 3 to 5) and more severe elastin degradation compared with Apoe −/− mice. Mechanistically, Apoe −/− SmgGDS +/− mice showed significantly higher levels of oxidative stress, matrix metalloproteinases, and inflammatory cell migration in the ascending aorta compared with Apoe −/− mice. For mechanistic analyses, we primary cultured AoSMCs from the 2 genotypes. After angiotensin II (100 nmol/L) treatment for 24 hours, Apoe −/− SmgGDS +/− AoSMCs showed significantly increased matrix metalloproteinase activity and oxidative stress levels compared with Apoe−/− AoSMCs. In addition, SmgGDS deficiency increased cytokines/chemokines and growth factors in AoSMCs. Moreover, expressions of fibrillin-1 (FBN1), α-smooth muscle actin (ACTA2), myosin-11 (MYH11), MYLLK , and PRKG1 , which are force generation genes, were significantly reduced in Apoe −/− SmgGDS +/− AoSMCs compared with Apoe−/− AoSMCs. A similar tendency was noted in AoSMCs from patients with TAA compared with those from control subjects. Finally, local delivery of the SmgGDS gene construct reversed the dilation of the ascending aorta in Apoe −/− SmgGDS +/− mice. Conclusions: These results suggest that SmgGDS is a novel therapeutic target for the prevention and treatment of TAA. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Background: Excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs) are key mechanisms of pulmonary arterial hypertension (PAH). Despite the multiple combination therapy, a considerable number of patients develop severe pulmonary hypertension (PH) because of the lack of diagnostic biomarker and antiproliferative therapies for PASMCs. Methods: Microarray analyses were used to identify a novel therapeutic target for PAH. In vitro experiments, including lung and serum samples from patients with PAH, cultured PAH-PASMCs, and high-throughput screening of 3336 low-molecular-weight compounds, were used for mechanistic study and exploring a novel therapeutic agent. Five genetically modified mouse strains, including PASMC-specific selenoprotein P (SeP) knockout mice and PH model rats, were used to study the role of SeP and therapeutic capacity of the compounds for the development of PH in vivo. Results: Microarray analysis revealed a 32-fold increase in SeP in PAH-PASMCs compared with control PASMCs. SeP is a widely expressed extracellular protein maintaining cellular metabolism. Immunoreactivity of SeP was enhanced in the thickened media of pulmonary arteries in PAH. Serum SeP levels were also elevated in patients with PH compared with controls, and high serum SeP predicted poor outcome. SeP-knockout mice (SeP–/–) exposed to chronic hypoxia showed significantly reduced right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary artery remodeling compared with controls. In contrast, systemic SeP-overexpressing mice showed exacerbation of hypoxia-induced PH. Furthermore, PASMC-specific SeP–/– mice showed reduced hypoxia-induced PH compared with controls, whereas neither liver-specific SeP knockout nor liver-specific SeP-overexpressing mice showed significant differences with controls. Altogether, protein levels of SeP in the lungs were associated with the development of PH. Mechanistic experiments demonstrated that SeP promotes PASMC proliferation and resistance to apoptosis through increased oxidative stress and mitochondrial dysfunction, which were associated with activated hypoxia-inducible factor-1α and dysregulated glutathione metabolism. It is important to note that the high-throughput screening of 3336 compounds identified that sanguinarine, a plant alkaloid with antiproliferative effects, reduced SeP expression and proliferation in PASMCs and ameliorated PH in mice and rats. Conclusions: These results indicate that SeP promotes the development of PH, suggesting that it is a novel biomarker and therapeutic target of the disorder. [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are fatal diseases; however, their pathogenesis still remains to be elucidated. We have recently screened novel pathogenic molecules and have performed drug discovery targeting those molecules. Pulmonary artery smooth muscle cells (PASMCs) in patients with PAH (PAH-PASMCs) have high proliferative properties like cancer cells, which leads to thickening and narrowing of distal pulmonary arteries. Thus, we conducted a comprehensive analysis of PAH-PASMCs and lung tissues to search for novel pathogenic proteins. We validated the pathogenic role of the selected proteins by using tissue-specific knockout mice. To confirm its clinical significance, we used patient-derived blood samples to evaluate the potential as a biomarker for diagnosis and prognosis. Finally, we conducted a high throughput screening and found inhibitors for the pathogenic proteins. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary arterial hypertension (PAH) is characterized by enhanced proliferation and reduced apoptosis of pulmonary artery smooth muscle cells (PASMCs). Hypothesis: To discover a novel compound for PAH patients from the original 5,562 compounds of Tohoku University. Methods: We performed high-throughput screening using PASMCs from PAH patients (PAH-PASMCs). Next, we performed functional tests for emetine in vivo. Results: We found that emetine inhibits PAH-PASMC proliferation. Interestingly, emetine significantly reduced activities of HIF-1α and -2α in PAH-PASMCs (n=3 each, P <0.05). Consistently, emetine reduced secretion of inflammatory cytokines/chemokines and growth factors, and oxidative stress-augmenting proteins such as cyclophilin A and its receptor basigin in PAH-PASMCs (n=3 each, P <0.05). Moreover, emetine significantly suppressed Rho-kinase activity in PAH-PASMCs (n=3 each, P <0.05). Additionally, emetine increased apoptosis, detected by TUNEL assay and reduced the expression of the anti-apoptotic protein Bcl2 in PAH-PASMCs (n=3 each, P <0.05). Next, we performed functional tests for emetine in vivo. Six-week-old male SD rats were used for the two experimental PH models; monocrotaline-induced PH and Sugen/hypoxia-induced PH. In the prevention protocol, after subcutaneous injection of monocrotaline (60 mg/kg), the animals were assigned to the simultaneous oral administration with emetine (0.05 mg/kg/day) or vehicle for 3 weeks. Emetine significantly reduced right ventricular (RV) systolic pressure (57±3 vs. 77±4 mmHg), RV hypertrophy (0.40±0.02 vs. 0.50±0.02), and PA remodeling compared with controls (all P <0.01, n=10~15). In the treatment protocol, after establishment of PH with Sugen (20 mg/kg) and hypoxia (10% O2) for 3 weeks followed by normoxia for 6 weeks, the animals were assigned to the oral administration of emetine (0.05 mg/kg/day) or vehicle for additional 4 weeks. Emetine significantly reduced RV systolic pressure (93±5 vs. 59±5 mmHg), RV hypertrophy (0.52±0.04 vs. 0.35±0.02), and PA remodeling compared with controls (all P <0.01, n=10~12). Importantly, emetine significantly reduced TNF-α and MCP-1 in serum compared with vehicle controls, suggesting its potent anti-inflammatory effects in vivo. Finally, emetine significantly reduced protein levels of cyclophilin A, basigin, and Rho-kinase activities in both models in vivo. Conclusions: We identified emetine as a novel promising drug for the treatment of PAH. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary arterial hypertension (PAH) is a fatal disease characterized by enhanced proliferation of pulmonary artery smooth muscle cells (PASMCs). However, all the drugs in clinical use target pulmonary vascular dilatation, which may not be an effective target for patients with advanced PAH. Celastramycin is a benzoyl pyrrole-type compound originally found in a bacteria extract with anti-inflammatory effects. We aimed to discover a novel drug for PAH that inhibits PASMC proliferation. Methods and Results: We screened 5,562 compounds from original library using high-throughput screening (HTS) system. Among the compounds, we identified that celastramycin (CEL), a benzoyl pyrrole-type compound originally found in a bacteria extract, inhibited the proliferation of PASMCs from patients with PAH (PAH-PASMCs) in a dose-dependent manner with minimal effects on PASMCs from healthy donors (n=8 each, P <0.05). Moreover, cell toxicity assays showed that CEL inhibited cell proliferation without any cell death in PAH-PASMCs (n=8 each, P <0.05). Mechanistic analysis demonstrated that CEL significantly inhibited ERK and NF-κB signaling in PAH-PAMSCs compared with vehicle controls (both P <0.05, n=4 each). Moreover, CEL significantly reduced protein levels of bromodomain-containing protein 4 (BRD4), a member of the BET family with inflammatory property, compared with vehicle controls (both P <0.05, n=6 each). Consistently, CEL treatment reduced reactive oxygen species (ROS) production in PAH-PASMCs with increased protein levels of NF-E2-related factor 2, a master regulator of cellular response against oxidative stress (n=8 each, P <0.05). Furthermore, using a Seahorse apparatus, which provides information on mitochondrial function through real-time measurements of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), we found that CEL recovered mitochondrial function in PAH-PASMCs. Indeed, metabolome analysis showed that CEL increased metabolites in TCA cycle in PAH-PASMCs. Finally, CEL treatment significantly ameliorated hypoxia-induced pulmonary hypertension (PH) in mice, monocrotaline-induced PH in rats, and Sugen/hypoxia-induced PH in rats (all P <0.05), in which we found significantly reduced cytokines/chemokines and growth factors in lung homogenates (e.g. IL-2, IL-6, and M-CSF). Conclusions: CEL is a potential novel drug for the treatment of PAH with anti-proliferative, anti-oxidative, and anti-inflammatory effects. [ABSTRACT FROM AUTHOR]

Background: Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by persistent elevation of pulmonary vascular resistance, which results in a striking increase in right ventricular (RV) afterload and subsequent failure. Pulmonary artery (PA) smooth muscle cells (PASMCs) from PAH patients exhibit a cancer-like phenotype with increased glycolysis (Hexokinase 2 activity) and reduced glucose oxidation (inhibition of pyruvate dehydrogenase (PDH)) promoting cell proliferation and apoptosis-resistant contributing to obliteration of the PA lumen. Emerging evidence have demonstrated a critical role for the histone methyltransferase EZH2 in cancer cell survival and several EZH2 inhibitors are now clinically investigated. However, its role in PAH remains unknown. We hypothesized that EZH2 expression is upregulated in PAH-PASMCs leading to PA remodeling. Methods and Results: Using Western blot (WB), we showed that EZH2 is upregulated in lungs, distal PAs and isolated PASMCs from PAH patients (p<0.01, n=10) compared to controls. Consistently, increased EZH2 expression was found in distal PAs from animal models mimicking PAH (monocrotaline and Sugen/Hypoxia). Using proteomic LC-MSMS approach followed by Maxquant/Andromeda analysis in PASMCs isolated from 4 PAH patients, we identified 139 proteins differentially expressed (27 up-regulated ≥ 1.2 or and 112 down-regulated ≤ 0.84; p ≤ 0.05) following EZH2 knockdown. Results of KEGG pathway analysis revealed that the tricarboxylic acid (TCA) cycle, carbon metabolism and metabolic pathways were the top significant pathways (FDR p-value <10-4). This suggests that EZH2 is important for regulating bioenergetic metabolism in PAH-PASMCs. In agreement with this, pharmacological (GSK126 or EPZ-6438) or molecular (siEZH2) inhibition of EZH2 leads to reduced expression (WB) of Hexokinase 2, pPDH and PDH. This was associated with a significant reduction in PAH-PASMC proliferation (Ki67 labeling and EdU assay, p<0.001) and resistance to apoptosis (Annexin V assay p<0.001). Conclusion: We provide evidence that EZH2 is overexpressed in human PAH and implicated in the pro-proliferative and anti-apoptotic phenotype of PAH-PASMCs. [ABSTRACT FROM AUTHOR]

Background: Thoracic aortic aneurysm (TAA) and dissection (TAD) are fatal diseases, which cause aortic rupture and sudden death. The small GTP-binding protein GDP dissociation stimulator (SmgGDS) is a crucial mediator of the pleiotropic effects of statins. Previous studies revealed that reduced force generation in AoSMCs causes TAA and TAD. Methods and Results: To examine the role of SmgGDS in TAA formation, we employed an angiotensin II (AngII, 1,000 ng/min/kg, 4weeks)-induced TAA model in Apoe-/-SmgGDS+/- (DKO)mice, in which 33% died suddenly due to TAA rupture, whereas there was no TAA rupture in Apoe-/- control mice. In contrast, there was no significant difference in the ratio of AAA rupture between the two genotypes. We performed ultrasound imaging every week to follow the serial changes in aortic diameters. The diameter of the ascending aorta progressively increased in DKO mice compared with Apoe-/- mice, whereas that of the abdominal aorta remained comparable between the two genotypes. Histological analysis of DKO mice showed dissections of major thoracic aorta in the early phase of AngII infusion (day 3~5) and more severe elastin degradation compared with Apoe -/- mice. Mechanistically, DKO mice showed significantly higher levels of oxidative stress, matrix metalloproteinases, and inflammatory cell migration in the ascending aorta compared with Apoe-/- mice. For mechanistic analyses, we primary cultured AoSMCs from the 2 genotypes. After AngII (100 nM) treatment for 24 hours, DKO AoSMCs showed significantly increased MMP activity and oxidative stress levels compared with Apoe-/- AoSMCs. In addition, SmgGDS deficiency increased cytokines/chemokines and growth factors in AoSMCs. Moreover, force generation genes were significantly reduced in DKO AoSMCs compared with Apoe-/- AoSMCs. Importantly, RhoA and RhoC activities were significantly decreased in DKO AoSMCs compared with Apoe-/- AoSMCs. Similar tendency was noted in AoSMCs from TAA patients compared with those from controls. Finally, local delivery of the SmgGDS gene construct reversed the dilation of the ascending aorta and prevented TAA rupture in DKO mice. Conclusions: These results suggest that SmgGDS is a novel therapeutic target for the prevention and treatment of TAA. [ABSTRACT FROM AUTHOR]

Background: Thoracic aortic aneurysm (TAA) and dissection are fatal diseases that cause aortic rupture and sudden death. The small GTP-binding protein GDP dissociation stimulator (SmgGDS) is a crucial mediator of the pleiotropic effects of statins. Previous studies revealed that reduced force generation in aortic smooth muscle cells (AoSMCs) causes TAA and thoracic aortic dissection.Methods: To examine the role of SmgGDS in TAA formation, we used an angiotensin II (1000 ng·min-1·kg-1, 4 weeks)-induced TAA model.Results: We found that 33% of Apoe-/- SmgGDS+/- mice died suddenly as a result of TAA rupture, whereas there was no TAA rupture in Apoe-/- control mice. In contrast, there was no significant difference in the ratio of abdominal aortic aneurysm rupture between the 2 genotypes. We performed ultrasound imaging every week to follow up the serial changes in aortic diameters. The diameter of the ascending aorta progressively increased in Apoe-/- SmgGDS+/- mice compared with Apoe-/- mice, whereas that of the abdominal aorta remained comparable between the 2 genotypes. Histological analysis of Apoe-/- SmgGDS+/- mice showed dissections of major thoracic aorta in the early phase of angiotensin II infusion (day 3 to 5) and more severe elastin degradation compared with Apoe-/- mice. Mechanistically, Apoe-/- SmgGDS+/- mice showed significantly higher levels of oxidative stress, matrix metalloproteinases, and inflammatory cell migration in the ascending aorta compared with Apoe-/- mice. For mechanistic analyses, we primary cultured AoSMCs from the 2 genotypes. After angiotensin II (100 nmol/L) treatment for 24 hours, Apoe-/- SmgGDS+/- AoSMCs showed significantly increased matrix metalloproteinase activity and oxidative stress levels compared with Apoe-/- AoSMCs. In addition, SmgGDS deficiency increased cytokines/chemokines and growth factors in AoSMCs. Moreover, expressions of fibrillin-1 ( FBN1), α-smooth muscle actin ( ACTA2), myosin-11 ( MYH11), MYLLK, and PRKG1, which are force generation genes, were significantly reduced in Apoe-/- SmgGDS+/- AoSMCs compared with Apoe-/- AoSMCs. A similar tendency was noted in AoSMCs from patients with TAA compared with those from control subjects. Finally, local delivery of the SmgGDS gene construct reversed the dilation of the ascending aorta in Apoe-/- SmgGDS+/- mice.Conclusions: These results suggest that SmgGDS is a novel therapeutic target for the prevention and treatment of TAA. [ABSTRACT FROM AUTHOR]

Background: Excessive proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs) are key mechanisms of pulmonary arterial hypertension (PAH). Despite the multiple combination therapy, a considerable number of patients develop severe pulmonary hypertension (PH) because of the lack of diagnostic biomarker and antiproliferative therapies for PASMCs.Methods: Microarray analyses were used to identify a novel therapeutic target for PAH. In vitro experiments, including lung and serum samples from patients with PAH, cultured PAH-PASMCs, and high-throughput screening of 3336 low-molecular-weight compounds, were used for mechanistic study and exploring a novel therapeutic agent. Five genetically modified mouse strains, including PASMC-specific selenoprotein P (SeP) knockout mice and PH model rats, were used to study the role of SeP and therapeutic capacity of the compounds for the development of PH in vivo.Results: Microarray analysis revealed a 32-fold increase in SeP in PAH-PASMCs compared with control PASMCs. SeP is a widely expressed extracellular protein maintaining cellular metabolism. Immunoreactivity of SeP was enhanced in the thickened media of pulmonary arteries in PAH. Serum SeP levels were also elevated in patients with PH compared with controls, and high serum SeP predicted poor outcome. SeP-knockout mice ( SeP-/-) exposed to chronic hypoxia showed significantly reduced right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary artery remodeling compared with controls. In contrast, systemic SeP-overexpressing mice showed exacerbation of hypoxia-induced PH. Furthermore, PASMC-specific SeP-/- mice showed reduced hypoxia-induced PH compared with controls, whereas neither liver-specific SeP knockout nor liver-specific SeP-overexpressing mice showed significant differences with controls. Altogether, protein levels of SeP in the lungs were associated with the development of PH. Mechanistic experiments demonstrated that SeP promotes PASMC proliferation and resistance to apoptosis through increased oxidative stress and mitochondrial dysfunction, which were associated with activated hypoxia-inducible factor-1α and dysregulated glutathione metabolism. It is important to note that the high-throughput screening of 3336 compounds identified that sanguinarine, a plant alkaloid with antiproliferative effects, reduced SeP expression and proliferation in PASMCs and ameliorated PH in mice and rats.Conclusions: These results indicate that SeP promotes the development of PH, suggesting that it is a novel biomarker and therapeutic target of the disorder. [ABSTRACT FROM AUTHOR]