Approach For Pulmonary Arterial Hypertension Research Articles

Improved Risk Prediction Using a Refined European Guidelines Instrument in Pulmonary Arterial Hypertension Related to Congenital Heart Disease

European guidelines advocate a goal-oriented treatment approach in pulmonary arterial hypertension (PAH), based on a comprehensive risk assessment instrument, which has been validated in several PAH subgroups. We investigated its discriminatory ability, and explored tricuspid annular plane systolic excursion (TAPSE) and revised thresholds to improve its predictability within the adult congenital heart disease (CHD) population.In total, 223 adults (42±16 years, 66% female, 68% Eisenmenger) were enrolled from five European PAH-CHD expert centers. Patients were classified as ‘Low’, ‘Intermediate’, or ‘High’ risk at baseline visit and at follow-up within 4-18 months. By the general PAH guidelines instrument, survival did not differ between the risk groups (P=n.s.), mostly due to skewed group distribution. Reclassifying patients using revised thresholds for N-terminal pro-brain natriuretic peptide (NT-proBNP) and 6-minute walk distance (6MWD) (i.e., ‘Low’, ‘Intermediate’, ‘High’ as <500, 500-1400, >1400 ng/l and >400, 165-400 and <165 m, respectively) and use of TAPSE (‘Low’, ‘Intermediate’, ‘High’ as >20, 16-20 and <16mm) significantly improved discrimination between the risk groups both at baseline and follow-up (P=0.001, ROC increase from 0.648 to 0.701), reclassifying 64 (29%) patients. Irrespective of follow-up risk group, survival was better for patients with higher proportions of low-risk variables. Improvement to a ‘Low-risk’ profile at a median of 9 months follow-up provided improved survival comparable to survival of patients who remained in the ‘Low risk’ group.In conclusion, the external validity of general risk instrument for PAH appeared to be of limited discriminatory value in PAH-CHD patients. We propose a refined risk instrument with improved discrimination for PAH-CHD.

Connexin43, A Promising Target to Reduce Cardiac Arrhythmia Burden in Pulmonary Arterial Hypertension.

While essential hypertension (HTN) is very prevalent, pulmonary arterial hypertension (PAH) is very rare in the general population. However, due to progressive heart failure, prognoses and survival rates are much worse in PAH. Patients with PAH are at a higher risk of developing supraventricular arrhythmias and malignant ventricular arrhythmias. The latter underlie sudden cardiac death regardless of the mechanical cardiac dysfunction. Systemic chronic inflammation and oxidative stress are causal factors that increase the risk of the occurrence of cardiac arrhythmias in hypertension. These stressful factors contribute to endothelial dysfunction and arterial pressure overload, resulting in the development of cardiac pro-arrhythmic conditions, including myocardial structural, ion channel and connexin43 (Cx43) channel remodeling and their dysfunction. Myocardial fibrosis appears to be a crucial proarrhythmic substrate linked with myocardial electrical instability due to the downregulation and abnormal topology of electrical coupling protein Cx43. Furthermore, these conditions promote ventricular mechanical dysfunction and heart failure. The treatment algorithm in HTN is superior to PAH, likely due to the paucity of comprehensive pathomechanisms and causal factors for a multitargeted approach in PAH. The intention of this review is to provide information regarding the role of Cx43 in the development of cardiac arrhythmias in hypertensive heart disease. Furthermore, information on the progress of therapy in terms of its cardioprotective and potentially antiarrhythmic effects is included. Specifically, the benefits of sodium glucose co-transporter inhibitors (SGLT2i), as well as sotatercept, pirfenidone, ranolazine, nintedanib, mirabegron and melatonin are discussed. Discovering novel therapeutic and antiarrhythmic strategies may be challenging for further research. Undoubtedly, such research should include protection of the heart from inflammation and oxidative stress, as these are primary pro-arrhythmic factors that jeopardize cardiac Cx43 homeostasis, the integrity of intercalated disk and extracellular matrix, and, thereby, heart function.

G9a/GLP Targeting Ameliorates Pulmonary Vascular Remodeling in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by progressive vascular remodeling of small pulmonary arteries (PAs) causing sustained elevation of PA pressure, right ventricular failure, and death. Similar to cancer cells, PA smooth muscle cells (PASMCs), which play a key role in pulmonary vascular remodeling, have adopted multiple mechanisms to sustain their survival and proliferation in the presence of stress. The histone methyltransferase G9a and its partner protein GLP (G9a-like protein) have been shown to exert oncogenic effects and to serve as a buffer against an exaggerated transcriptional response. Therefore, we hypothesized that upregulation of G9a and GLP in PAH plays a pivotal role in pulmonary vascular remodeling by maintaining the abnormal phenotype of PAH-PASMCs. We found that G9a is increased in PASMCs from patients with PAH as well as in remodeled PAs from animal models. Pharmacological inhibition of G9a/GLP activity using BIX01294 and UNC0642 significantly reduced the prosurvival and proproliferative potentials of cultured PAH-PASMCs. Using RNA sequencing, further exploration revealed that G9a/GLP promotes extracellular matrix production and affords protection against the negative effects of an overactive stress response. Finally, we found that therapeutic treatment with BIX01294 reduced pulmonary vascular remodeling and lowered mean PA pressure in fawn-hooded rats. Treatment of Sugen/hypoxia-challenged mice with BIX01294 also improved pulmonary hemodynamics and right ventricular function. In conclusion, these findings indicate that G9a/GLP inhibition may represent a new therapeutic approach in PAH.

1,8-Cineole ameliorates right ventricle dysfunction associated with pulmonary arterial hypertension by restoring connexin43 and mitochondrial homeostasis

For the first time, the present study unravels a cardiospecific therapeutic approach for Pulmonary Arterial Hypertension (PAH), a disease with a very poor prognosis and high mortality rates due to right ventricle (RV) dysfunction. We first established a new in vitro model of high-pressure-induced hypertrophy that closely resembles heart defects associated with PAH and validated our in vitro findings on a preclinical in vivo model of monocrotaline (MCT)-induced PAH. Our results showed the in vitro antihypertrophic effect of 1,8-cineole, a monoterpene widely found in several essential oils. Also, a decrease in RV hypertrophy and fibrosis, and an improvement in heart function in vivo was observed, when 1,8-cineole was applied topically. Furthermore, 1,8-cineole restored gap junction protein connexin43 distribution at the intercalated disks and mitochondrial functionality, suggesting it may act by preserving cardiac cell-to-cell communication and bioenergetics. Overall, our results point out a promising therapeutic compound that can be easily applied topically, thus paving the way for the development of effective cardiac-specific therapies to greatly improve PAH outcomes.

Abstract 10248: Regulation of the Methylation and Expression Levels of the Bmpr2 Gene by Sin3a as a Novel Therapeutic Mechanism in Pulmonary Arterial Hypertension

Background: Epigenetic mechanisms are critical in the pathogenesis of pulmonary arterial hypertension (PAH). Previous studies have suggested that hypermethylation of the Bone Morphogenetic Protein Receptor Type 2 (BMPR2) promoter is associated with BMPR2 downregulation and progression of PAH. Here, we investigated for the first time the role of Switch-Independent 3a (SIN3a), a transcriptional regulator, in the epigenetic mechanisms underlying hypermethylation of BMPR2 in the pathogenesis of PAH. Methods: We used lung samples from PAH patients and non-PAH controls, preclinical mouse and rat PAH models, and human pulmonary arterial smooth muscle cells (hPASMC). Expression of SIN3a was modulated using a lentiviral vector or a siRNA in vitro and a specific Adeno-Associated Virus serotype 1 (AAV1) or a lentivirus encoding for human SIN3a in vivo . Results: SIN3a is a known transcriptional regulator; however, its role in cardiovascular diseases, especially PAH, is unknown. Interestingly, we detected a dysregulation of SIN3 expression in patients and in rodent models, which is strongly associated with decreased BMPR2 expression. SIN3a is known to regulate epigenetic changes. Therefore, we tested its role in the regulation of BMPR2 and found that BMPR2 is regulated by SIN3a. Interestingly, SIN3a overexpression inhibited hPASMC proliferation and upregulated BMPR2 expression by preventing the methylation of the BMPR2 promoter region. RNA sequencing analysis suggested that SIN3a downregulated the expression of DNA and histone methyltransferases such as DNMT1 and EZH2 while promoting the expression of the DNA demethylase TET1. Mechanistically, SIN3a promoted BMPR2 expression by decreasing CTCF binding to the BMPR2 promoter. Finally, we identified intratracheal delivery of AAV1.hSIN3a to be a beneficial therapeutic approach in PAH- by attenuating pulmonary vascular and RV remodeling, decreasing RVSP and mPAP pressure, and restoring BMPR2 expression in rodent models of PAH. Conclusions: Altogether, our study unveiled the protective/beneficial role of SIN3a in pulmonary hypertension. We also identified a novel and distinct molecular mechanism by which SIN3a regulates BMPR2 in hPASMC.

Abstract 12266: Endothelial Cells Senescence Exacerbates Pulmonary Hypertension Through Notch-Induced Pulmonary Arterial Smooth Muscle Cells Proliferation and Migration

Background: Endothelial cell (EC) dysfunction is critically involved in the pathogenesis of pulmonary arterial hypertension (PAH) by mediating structural changes in vasculatures. Various stress that promotes EC dysfunction also induces premature senescence in EC; however, the role of EC senescence in the development of PAH remains unknown. Hypothesis: We hypothesized that senescent ECs play a significant role in the development of PAH. Methods: We generated EC-specific progeroid mice that overexpress the dominant-negative form of telomere repeat binding factor 2 under the control of the VE-cadherin promoter. Following chronic hypoxia exposure, PH phenotypes were assessed by RVSP and lung histology. Gene expression was assessed by RT-qPCR. The interaction of pulmonary artery ECs (PAECs) and pulmonary artery smooth muscle cells (PASMCs) was analyzed using indirect and direct co-culture systems. In addition, gamma-secretase inhibitor (DAPT) was used to inhibit Notch signaling both in the in-vitro and in-vivo studies. Results: The transgene expression was specifically expressed and fairly distributed in various pulmonary blood vessels in EC-specific progeroid mice. After three weeks of hypoxia exposure, EC-specific progeroid mice exhibited exacerbated pulmonary hypertension (PH) phenotype, accompanied by the prominent medial thickening and enhanced proliferation capacity of SMCs in the distal pulmonary arteries. Interestingly, contact-mediated interaction with senescent ECs increased proliferation and migration capacities in SMCs, while the absence of EC-SMC contact abolished those effects. Mechanistically, senescent ECs expressed higher Notch ligands than in young ECs, leading to the enhanced Notch signaling in PASMCs. Consistently, pharmacological inhibition of Notch signaling attenuated senescent ECs’ effects on SMCs in vitro and the PH phenotype in EC-specific progeroid mice in vivo. Conclusions: These findings established the critical roles of senescent ECs in the PAH pathogenesis, suggesting a novel pathological-targeted therapeutic approach for PAH.

Blueberry extract improves redox balance and functional parameters in the right ventricle from rats with pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a disease characterized by increased pulmonary vascular resistance and right ventricle (RV) failure. In this context, oxidative stress is an essential element contributing to PAH's pathophysiology. Thus, blueberry (BB), which has a high antioxidant capacity, emerges as a natural therapeutic approach in PAH. This work evaluated the effect of BB extract on redox balance in RV in a PAH's animal model. Male Wistar rats (200 ± 20g) (n = 72) were randomized into eight groups: control (CTR); monocrotaline (MCT); CTR and MCT treated at doses of 50, 100, and 200mg/kg BB. PAH was induced by administration of MCT (60mg/kg, intraperitoneal). Rats were treated with BB orally for 5weeks (2weeks before monocrotaline and 3weeks after monocrotaline injection). On day 35, rats were submitted to echocardiography and catheterization, then euthanasia and RV harvesting for biochemical analyses. RV hypertrophy, observed in the MCT groups, was reduced with BB treatment. MCT elevated RV systolic pressure and pressure/time derivatives, while the intervention with BB decreased these parameters. PAH decreased RV output and pulmonary artery outflow acceleration/ejection time ratio, while increased RV diameters, parameters restored by BB treatment. Animals from the MCT group showed elevated lipid peroxidation and NADPH oxidase activity, outcomes attenuated in animals treated with BB, which also led to increased catalase activity. Treatment with BB partially mitigated PAH, which could be associated with improvement of RV redox state. Such findings constitute an advance in the investigation of the role of BB extract in chronic progressive cardiovascular diseases that involve the redox balance, such as PAH.

Regulation of the Methylation and Expression Levels of the BMPR2 Gene by SIN3a as a Novel Therapeutic Mechanism in Pulmonary Arterial Hypertension.

Epigenetic mechanisms are critical in the pathogenesis of pulmonary arterial hypertension (PAH). Previous studies have suggested that hypermethylation of the BMPR2 (bone morphogenetic protein receptor type 2) promoter is associated with BMPR2 downregulation and progression of PAH. Here, we investigated for the first time the role of SIN3a (switch-independent 3a), a transcriptional regulator, in the epigenetic mechanisms underlying hypermethylation of BMPR2 in the pathogenesis of PAH. We used lung samples from PAH patients and non-PAH controls, preclinical mouse and rat PAH models, and human pulmonary arterial smooth muscle cells. Expression of SIN3a was modulated using a lentiviral vector or a siRNA in vitro and a specific adeno-associated virus serotype 1 or a lentivirus encoding for human SIN3a in vivo. SIN3a is a known transcriptional regulator; however, its role in cardiovascular diseases, especially PAH, is unknown. It is interesting that we detected a dysregulation of SIN3 expression in patients and in rodent models, which is strongly associated with decreased BMPR2 expression. SIN3a is known to regulate epigenetic changes. Therefore, we tested its role in the regulation of BMPR2 and found that BMPR2 is regulated by SIN3a. It is interesting that SIN3a overexpression inhibited human pulmonary arterial smooth muscle cells proliferation and upregulated BMPR2 expression by preventing the methylation of the BMPR2 promoter region. RNA-sequencing analysis suggested that SIN3a downregulated the expression of DNA and histone methyltransferases such as DNMT1 (DNA methyltransferase 1) and EZH2 (enhancer of zeste 2 polycomb repressive complex 2) while promoting the expression of the DNA demethylase TET1 (ten-eleven translocation methylcytosine dioxygenase 1). Mechanistically, SIN3a promoted BMPR2 expression by decreasing CTCF (CCCTC-binding factor) binding to the BMPR2 promoter. Last, we identified intratracheal delivery of adeno-associated virus serotype human SIN3a to be a beneficial therapeutic approach in PAH by attenuating pulmonary vascular and right ventricle remodeling, decreasing right ventricle systolic pressure and mean pulmonary arterial pressure, and restoring BMPR2 expression in rodent models of PAH. All together, our study unveiled the protective and beneficial role of SIN3a in pulmonary hypertension. We also identified a novel and distinct molecular mechanism by which SIN3a regulates BMPR2 in human pulmonary arterial smooth muscle cells. Our study also identified lung-targeted SIN3a gene therapy using adeno-associated virus serotype 1 as a new promising therapeutic strategy for treating patients with PAH.

Therapeutic antibody approach for pulmonary arterial hypertension

Therapeutic antibody approach for pulmonary arterial hypertension

Disease severity-related alterations of cardiac microRNAs in experimental pulmonary hypertension.

Right ventricular (RV) failure is the primary cause of death in pulmonary arterial hypertension (PAH). We hypothesized that heart‐relevant microRNAs, that is myomiRs (miR‐1, miR‐133a, miR‐208, miR‐499) and miR‐214, can have a role in the right ventricle in the development of PAH. To mimic PAH, male Wistar rats were injected with monocrotaline (MCT, 60 mg/kg, s.c.); control group received vehicle. MCT rats were divided into two groups, based on the clinical presentation: MCT group terminated 4 weeks after MCT administration and prematurely terminated group (ptMCT) displaying signs of terminal disease. Myocardial damage genes and candidate microRNAs expressions were determined by RT‐qPCR. Reduced blood oxygen saturation, breathing disturbances, RV enlargement as well as elevated levels of markers of myocardial damage confirmed PH in MCT animals and were more pronounced in ptMCT. MyomiRs (miR‐1/miR‐133a/miR‐208a/miR‐499) were decreased and the expression of miR‐214 was increased only in ptMCT group (P < 0.05). The myomiRs negatively correlated with Fulton index as a measure of RV hypertrophy in MCT group (P < 0.05), whereas miR‐214 showed a positive correlation (P < 0.05). We conclude that the expression of determined microRNAs mirrored the disease severity and targeting their pathways might represent potential future therapeutic approach in PAH.

P1803Refining the 2015 European guidelines risk assessment tool for pulmonary arterial hypertension in adult congenital heart disease

Abstract Background Current European guidelines advocate a goal-oriented treatment approach in pulmonary arterial hypertension (PAH), based on a comprehensive risk assessment. However, this instrument has been based predominantly on patients with idiopathic PAH and its accuracy has not been well established for PAH associated with congenital heart disease (CHD)–a patient population known to be distinctly different for other PAH aetiologies. Purpose To investigate the discriminatory ability of the guidelines risk assessment tool and explore the benefit of including other cut-offs or variables in PAH-CHD. Methods and results Data from 112 PAH-CHD patients (age 42.1±16 years, 70% Eisenmenger, 38% Down syndrome) seen between 2004 and 2016 at two specialized adult PAH-CHD expert centres were prospectively collected. Patients were classified as “Low”, “Intermediate”, or “High” risk following the strategy proposed by Kylhammar (Eur Heart J, 2017) based on N-terminal pro-brain natriuretic peptide (NT-proBNP), 6-minute walk distance, functional class and imaging parameters and analysed by Kaplan-Meier method, truncated at 5 years. At baseline, 25% (28) of patients were classified as “Low risk”, 69% (77) as “Intermediate risk” and 6% (7) as “High risk”. Although survival was better (P=0.012) for patients with higher proportions of “Low risk” variables, this method did not discriminate well between the three risk groups (Figure 1A, P=0.371). One-year survival estimates corresponded moderately to those proposed by the guidelines, 96.4% in the “Low risk” (vs. &gt;95%), 94.8% in the “Intermediate risk” (vs. 90–95%), and 85.7% in the “High risk” (vs. &lt;90%) baseline cohorts, respectively. Analysis of different cut-off values for NT-proBNP (i.e., “Low”, “Intermediate”, “High” as &lt;500, 500–1440 and &gt;1400 ng/l, respectively) and use of tricuspid annular plane systolic excursion (TAPSE) measurements (“Low”, “Intermediate”, “High” as &lt;1.6, 2.6–2.7 and &gt;2.7 cm, respectively) as imaging parameter instead of right atrial area improved discrimination between the risk groups (Figure 1B). With these adjustments to the risk assessment tool, survival differed between all three risk groups (P&lt;0.001). Figure 1 Conclusion Our preliminary findings suggest that an updated version of the European guidelines risk assessment tool–with different cut-off values for NT-proBNP and use of TAPSE–discriminates more accurately in the PAH-CHD population. Further analysis will be performed to estimate the prognostic benefit of reaching a “Low risk” profile, as this is the recommended treatment goal.

Association of N-Terminal Pro Brain Natriuretic Peptide and Long-Term Outcome in Patients With Pulmonary Arterial Hypertension.

NT-proBNP (N-terminal pro brain natriuretic peptide) levels are included in the multiparametric risk assessment approach for pulmonary arterial hypertension (PAH) outlined in PAH guidelines. However, data supporting the use of NT-proBNP risk thresholds in assessing prognosis in PAH are limited. The GRIPHON trial (Prostacyclin [PGI2] Receptor Agonist In Pulmonary Arterial Hypertension) provides an opportunity to assess the prognostic value of NT-proBNP thresholds in a controlled clinical trial and to evaluate the response to selexipag according to these thresholds. The event-driven GRIPHON trial randomly assigned patients to selexipag or placebo. NT-proBNP was measured at regular intervals in GRIPHON. Here, patients were categorized post hoc into low, medium, and high NT-proBNP subgroups according to 2 independent sets of thresholds: (1) baseline tertiles: <271 ng/L; 271 to 1165 ng/L; >1165 ng/L; and (2) 2015 European Society of Cardiology/European Respiratory Society guidelines cutoffs: <300 ng/L; 300 to 1400 ng/L; >1400 ng/L. Hazard ratios (selexipag versus placebo) with 95% CIs were calculated for the primary end point (composite morbidity/mortality events) by NT-proBNP category at baseline using Cox proportional-hazards models, and at any time during the exposure period using a time-dependent Cox model. With both thresholds, baseline and follow-up NT-proBNP categories were highly prognostic for future morbidity/mortality events during the study ( P<0.0001). In the time-dependent analysis, the risk of experiencing a morbidity/mortality event was 92% and 83% lower in selexipag-treated patients with a low and medium NT-proBNP level, and 90% and 56% lower in placebo-treated patients with a low and medium NT-proBNP level, in comparison with patients with a high NT-proBNP level. Selexipag reduced the risk of morbidity/mortality events across all 3 NT-proBNP categories in both the baseline and time-dependent analyses, with a more pronounced treatment benefit of selexipag seen in the medium and low NT-proBNP subgroups (interaction P values 0.20 and 0.007 in the baseline and time-dependent analyses). These analyses further establish the prognostic relevance of NT-proBNP levels in PAH and provide first evidence for the association of NT-proBNP level and treatment response. Using 2 similar sets of thresholds, these analyses support the relevance of the low, medium, and high NT-proBNP categories as part of the multiparametric risk assessment approach outlined in the European Society of Cardiology/European Respiratory Society guidelines for the management of PAH patients. URL: https://www.clinicaltrials.gov . Unique identifier: NCT01106014.

A comprehensive risk stratification at early follow-up determines prognosis in pulmonary arterial hypertension.

Guidelines recommend a goal-oriented treatment approach in pulmonary arterial hypertension (PAH). The aim is to reach a low-risk profile, as determined by a risk assessment instrument. This strategy is incompletely validated. We aimed to investigate the bearing of such risk assessment and the benefit of reaching a low-risk profile. Five hundred and thirty PAH patients were included. Follow-up assessments performed after a median of 4 (interquartile range 3-5) months were available for 383 subjects. Patients were classified as 'Low', 'Intermediate', or 'High risk' and the benefit of reaching the 'Low risk' group was estimated. Survival differed (P < 0.001) between the risk groups at baseline and at follow-up. Survival was similar for patients who remained in or improved to the 'Low risk' group. Survival was similar for patients who remained in or worsened to the 'Intermediate risk' or 'High risk' groups. Irrespective of follow-up risk group, survival was better (P < 0.001) for patients with a higher proportion of variables at low risk. Results were unchanged after excluding patients with idiopathic PAH >65 years at diagnosis, and when patients with idiopathic or connective tissue disease-associated PAH were analysed separately. Patients in the 'Low risk' group at follow-up exhibited a reduced mortality risk (hazard ratio 0.2, 95% confidence interval 0.1-0.4 in multivariable analysis adjusted for age, sex and PAH subset), as compared to patients in the 'Intermediate risk' or 'High risk' groups. These findings suggest that comprehensive risk assessments and the aim of reaching a low-risk profile are valid in PAH.

A new fast molecular genetic diagnostic approach for pulmonary arterial hypertension

Background: In this study we developed a new specific gene panel for pulmonary arterial hypertension (PAH) including major disease genes and further candidates.

Abstract 382: Cyclophilin A (CypA) is a Pathogenic Mediator of Pulmonary Arterial Hypertension

Rationale: Pulmonary arterial hypertension (PAH) is a devastating disease in which oxidative stress has been proposed to mediate pathological changes to the pulmonary vasculature such as endothelial cell (EC) apoptosis, endothelial to mesenchymal transition (EndMT), vascular smooth muscle cell (VSMC) proliferation, and inflammation. Our previous study showed that cyclophilin A (CypA) was secreted from EC and VSMC in response to oxidative stress, and much of the secreted CypA was acetylated (AcK-CypA). Furthermore, CypA was increased in the plasma of patients with PAH. Objective: To evaluate the cell- s pecific role of CypA in PAH and compare the relative effects of AcK-CypA and CypA on EC apoptosis, development of an inflammatory EC phenotype and EndMT. Methods and Results: Transgenic overexpression of CypA in EC, but not SMC, caused a PAH phenotype including increased pulmonary artery pressure, α-smooth muscle actin expression in small arteries, and CD45 positive cells in the lungs. Mechanistic analysis using cultured mouse lung microvascular EC showed that CypA and AcK-CypA increased apoptosis measured by caspase 3 cleavage and TUNEL staining. MM284, a specific inhibitor of extracellular CypA, prevented EC apoptosis. In addition, CypA and AcK-CypA promoted an EC inflammatory phenotype assessed by increased VCAM1 and ICAM1 expression, phosphorylation of p65, and degradation of IkB. Furthermore, CypA and AcK-CypA promoted EndMT assayed by change in cell morphology, increased mesenchymal markers and EndMT related transcription factors. At all concentrations, AcK-CypA stimulated greater increases in apoptosis, inflammation and EndMT than CypA. Conclusions: EC-derived CypA (especially AcK-CypA) causes PAH by a presumptive mechanism involving increased EC apoptosis, inflammation and EndMT. Our results suggest that inhibiting extracellular secreted CypA is a novel therapeutic approach for PAH.

Epigenetic modulation as a therapeutic approach for pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a rare but progressive and currently incurable disease, which is characterized by vascular remodeling in association with muscularization of the arterioles, medial thickening and plexiform lesion formation. Despite our advanced understanding of the pathogenesis of PAH and the recent therapeutic advances, PAH still remains a fatal disease. In addition, the susceptibility to PAH has not yet been adequately explained. Much evidence points to the involvement of epigenetic changes in the pathogenesis of a number of human diseases including cancer, peripheral hypertension and asthma. The knowledge gained from the epigenetic study of various human diseases can also be applied to PAH. Thus, the pursuit of novel therapeutic targets via understanding the epigenetic alterations involved in the pathogenesis of PAH, such as DNA methylation, histone modification and microRNA, might be an attractive therapeutic avenue for the development of a novel and more effective treatment. This review provides a general overview of the current advances in epigenetics associated with PAH, and discusses the potential for improved treatment through understanding the role of epigenetics in the development of PAH.

Monitoring and Diagnostic Approaches for Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis.

Pulmonary arterial hypertension (PAH) is one of the leading causes of death in patients with systemic sclerosis (SSc). Given the high prevalence and poor survival of SSc-PAH, and that aggressive management of mild disease may be associated with better outcomes, screening is critical. Right heart catheterization (RHC) is the gold standard for the definitive diagnosis of PAH, and should be performed in those patients in whom this diagnosis is suspected. Once a diagnosis of PAH is confirmed by RHC, treatment with PAH-specific therapies should be initiated as soon as possible.

A novel therapeutic approach in pulmonary arterial hypertension as a complication of adult‐onset Still's disease: targeting IL‐6

Adult-onset Still's Disease (AOSD), often though as the adult variant of systemic juvenile idiopathic arthritis (JIA), has an incidence of 1-3 cases per 1 million. Cardinal manifestations include fever, arthritis, skin rash, sore throat, hepatosplenomegaly and lymphadenopathy. Prolongation in diagnosing this disease results from its similarity to infectious, malignant and rheumatic diseases and lack of biomarkers. Pulmonary arterial hypertension (PAH) is a rare pulmonary complication of AOSD, and we are aware of only six cases reported in literature to date. Here we present a patient with AOSD who has developed pulmonary hypertension as a complication. We report a case of AOSD complicated by PAH treated successfully with tocilizumab, a humanized monoclonal antibody to human interleukin (IL)-6 receptor. A Pubmed and Medline search for evidence of pulmonary hypertension in AOSD and use of IL-6 inhibition in management was performed. Data for this study was collected from the patient's chart records. No infectious or neoplastic cause of her disease was identified and after extensive diagnostic workup, the patient was diagnosed with AOSD fulfilling Yamaguchi criteria. After initiation of IL-6 therapy the patient was followed over time to monitor the hemodynamic changes in pulmonary vasculature. Following treatment with Tocilizumab, the patient showed dramatic improvement in her clinical symptoms and remains in remission, through combination of tocilizumab (8 mg/kg), methotrexate and prednisone. Improvement of systemic symptoms, right heart catheterization (RHC) findings and the VECTRA-DA score served as a measure of treatment response. Tocilizumab has been effective in demonstrating marked improvement in both the clinical and laboratory parameters. Tocilizumab is an effective novel treatment for AOSD with PAH. This is the first documented report of successful use of tocilizumab in AOSD patients presenting with PAH. Prospective comparative studies could help validate its efficacy and safety.

T4 Mutations in BMPR-II Promote Inflammation Via Altered Superoxide Signalling: Insights into the Mechanisms Underlying Pulmonary Arterial Hypertension

IntroductionAlthough the presence of inflammation is well recognised in pulmonary arterial hypertension (PAH), the underlying mechanisms remain poorly understood. Mutations in the bone morphogenetic protein type II receptor gene, BMPR2,...

498 Targeting the Receptor of Advanced Glycation End Products: A New Therapeutic Approach in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a vasculopathy characterized by enhanced pulmonary artery smooth muscle cells (PASMC) proliferation and suppressed apoptosis. This results in both increase in pulmonary arterial pressure and pulmonary vascular remodeling. Recent studies have shown the implication of different transcription factors and proteins such as signal of transducer and activator of transcription 3 (STAT3), bone morphogenetic protein receptor 2 (BMPR2) and peroxisome proliferator-activated receptor gamma (PPARã) in the etiology of PAH.