GINA THAYER and GREGORY ROTH
Pulmonary hypertension (PHTN) is a major cause of death and disability worldwide, but its total global impact on health has never been estimated. This project will distinguish PHTN it as its own unique cause within the Global Burden of Disease study, producing comparable and consistent estimates of PHTN burden over time, by age and sex, and across all global locations. These burden estimates will capture both fatal and nonfatal disease measures, including incidence, prevalence, years of life lost (YLLs) (due to premature death from a disease), and years lived with disability (YLDs). YLLs and YLDs will then be summed to estimate disability-adjusted life years (DALYs), an overall measure of fatal and nonfatal disease burden. These novel estimates will serve as a guide to better inform PHTN funding, research priorities, health system decisions, and clinical development efforts.
WILLIAM M. OLDHAM
This is a study to characterize the effects of taurine, the most abundant free intracellular amino acid in humans and a key component of a variety of energy drinks, on the development of experimental pulmonary hypertension. In Aim 1, human pulmonary artery endothelial cells will be treated with taurine or inhibitors of taurine uptake. The effects of taurine excess and deficiency on cell phenotype, including proliferation, migration, and tube formation will be assessed. Further, the effects of taurine on gene transcription and intracellular signaling pathways will be measured. In Aim 2, the hemodynamic effects of taurine supplementation on the development of pulmonary hypertension in the Sugen plus hypoxia rat model will be determined by right and left heart catheterization. Histologic assessment of pulmonary and cardiac remodeling will be performed and intracellular signaling pathways will be interrogated. These studies will identify key taurine-mediated signaling pathways that contribute to pulmonary vascular remodeling.
Our study hypothesizes that there are genetic or Omic differences underlying differential responses to treatment with imatinib in PAH and that ultimately these can be used to identify patients likely to benefit most from imatinib treatment. This project proposes to study differences in gene variants, RNA expression and proteomics to determine which marker or markers most closely segregates with clinical treatment responses. Biologic specimens will be obtained from treated patients.
Pulmonary arterial hypertension (PAH) affects three to four times as many women as men, although PAH-afflicted women appear to live longer than PAH-afflicted men. However, the question of sex-based differences in disease prevalence and therapeutic response remains unanswered and perplexing. A primary reason for this standstill is the lack of experimental models that sufficiently and reliably reproduce human PAH. Investigators have traditionally used intact animal and cellular models for studying PAH pathophysiology and its gender disparity. However, these models cannot accurately portray the sex-based differences in PAH. In this study, we propose a novel approach to overcoming the limitations of the existing PAH models, by using bioengineered three-dimensional microfluidic models that mimic the anatomy and physiology of the pulmonary arteries of both women and men afflicted with PAH. As such, here we will test the proof-of-concept concerning seeding and growing cells of the pulmonary arteries (PACs) of PAH-afflicted male and female patients, creating a PAH-afflicted pulmonary artery on a microfluidic chip that can potentially be used for studying sex-based pathogenesis and personalized therapy for men and women affected by this currently incurable disease.
A grant in support of the development of Pulmonary Circulation, the first peer reviewed scientific journal to publish original research articles, review articles, case reports, and guidelines that are related to the pulmonary circulation, pulmonary vascular disease and lung injury. The grant provides scientific and operational support for the journal’s goal of disseminating research globally to improve patient care and research outcomes.
Given that PAH and cancer cells share numerous similarities, this opens the possibility of exploiting therapeutic agents used in cancer to treat PAH. Due to rapid metabolism and growth rate, cancer cells generally exhibit hallmarks of increased cellular stresses. Therefore, cancer cells are often more dependent on the stress support pathways for survival. DNA replication stress (RS) is defined as inefficient DNA replication that cause DNA replication forks to progress slowly or stall, making them susceptible to DNA damage. Compelling evidence indicate that cancer cells rely on an efficient RS response for viability. The ability of cells to cope with RS is largely dependent on the checkpoint kinase 1 (CHK1). The current proposal aims to demonstrate that, as observed in cancer cells, RS is a feature of PAH-PASMCs and that PAH-PASMCs adapt to RS by favoring the maintenance and the recovery of stalled replication forks. Our preliminary data demonstrating that RS markers and CHK1 expression/activation are increased in human PAH-PASMCs provide convincing arguments to the working hypothesis that CHK1 overexpression is essential for proliferation and survival by preventing excessive RS. The central objective of this proposal is to mechanistically investigate in human the role of CHK1 as a central integrator of PASMC proliferation, resistance to apoptosis and uncover a specific and promising avenue to tackle PAH. Specifically, we will pursue the following research objectives: In AIM1, we will determine whether PAH-PASMCs exhibit constitutively elevated levels of RS markers as well as increased expression of genes involved in RS response; in AIM2, we will determine whether molecular and pharmacological inhibition of CHK1 enhances RS, selectively hinders proliferation and promotes apoptotic death in PAH-PASMCs. In AIM3, we will test whether pharmacological CHK1 inhibition reverses PAH in animal models. In conclusion, the accomplishment of the current proposal will demonstrate the importance of RS coping mechanisms in the etiology of PAH.
In parts of Africa, 57% of HIV patients were coinfected with schistosomiasis. The aim of this study is to assess the inflammatory and immunological profile and to evaluate the pathobiology of co-infection on the remodelling process of the pulmonary vascular system in experimental animals.
PPHNet BOLD is the biorepository program of the Pediatric Pulmonary Hypertension Network (PPHNet), designed to link to PPHNet’s meticulously phenotyped cohort of patients enrolled at the PPHNet Research Centers across North America. PPHNet-BOLD will: (1) serve as a centralized resource of DNA, RNA, plasma, serum, and circulating peripheral blood mononuclear cells for PPHNet; (2) generate sequencing data to determine the frequency of known PH-associated gene mutations in multiple forms of pediatric PH; and, (3) serve as the bioprepository program for future PPHNet Research Projects.
MINGYI YAO and TAMER ELBAYOUMIC
Elevation of extracellular matrix glycoprotein thrombospondin 1 (TSP1) is has been strongly implicated in patients with clinical PAH cases. Beyond being a biomarker, the pathological roles of TSP1 in initiation and/or progression in PAH, and ischemia-reperfusion injury has been revealed and mechanisms of TSP1-initiated tissue and organ damage intensively studied. Our laboratories first identified a peptide that successfully antagonizes TSP1-damaged vaso-relaxation in isolated mouse thoracic aorta in a “proof-of-concept” study. Our extensive pilot ex-vivo data established the identified peptide - via its active TSP1-binding domain - as a candidate therapy to effectively protect and restore TSP1-impaired vasodilation mimicking pathological cardiovascular conditions due to the presence of a high level of TSP1 in patients’ circulation. The present project pursues the development of a prototype pharmaceutical formulation of our drug candidate, coupled to FDA approved nanocarrier (liposomes, Lip), in order to achieve maximal clinical efficacy. Multiple peptide molecules bio-conjugated onto each nano-liposome can bind circulating TSP1, forming complexes between liposomal-peptide and TSP1, which can then be eliminated via the reticulo-endothelial system. Hence, pathologically excessive TSP1 in circulation will be lowered down to normal or even subnormal levels. Essentially, the peptide is “nano-modified” to become the candidate decoy therapy to defuse/neutralize/eliminate elevated TSP1 in PAH.
Caveolin-1 (≈ 22 kD protein), a major constituent of the lipid rafts of plasma membrane known as caveolae, plays a key role in the initiation and the progression of pulmonary arterial hypertension (PAH). It is present on a number of cells including endothelial, epithelial, and smooth muscle cells; and through its scaffolding domain, it maintains the target proteins within caveolae in an inactive state. By this mechanism, caveolin-1 regulates eNOS function, Ca2+ entry, antioxidants, cell cycle, mitochondrial stability, and glucose and lipid metabolism. Based on our studies, we hypothesize that the loss of caveolin-1 in neointimal cells plays a critical role in the irreversibility of PAH. Our main aim is to test the hypothesis that restitution of caveolin-1 function in neointimal cells will halt the progression of PAH. We will evaluate two rodent models of PAH (MCT + hypoxia and Sugen + hypoxia) shown to exhibit neointima formation.
A study to evaluate the therapeutic potential of FDI-6 (a FOXM1 inhibitor) for the treatment of PAH. In AIM1, we will test the hypothesis that FOXM1 contributes to PAH-PASMC proliferation and resistance to apoptosis. Selective pharmacological and molecular loss of function approaches will be used. In AIM2, we will identify the mechanisms by which FOXM1 regulates these processes and investigate the molecular mechanisms accounting for its overexpression in PAH-PASMCs. In AIM3, we will evaluate the therapeutic potential of 2 FOXOM1 inhibitors (FDI-6 and a cell-penetrating ARF peptide inhibitor) on exercise capacity, pulmonary hemodynamic variables and right ventricular function in the Sugen/Hypoxia-induced PAH rat model.
Hossein Ardeschir Ghofrani and Djuro Kosanovic
We hypothesize that various endothelial and inflammatory cell-derived MPs possess all required properties and characteristics to represent promising future biomarkers for the patients with HAPH. Furthermore, we hypothesize that prominent cold exposure, frequently present “companion” associated with hypoxic condition at high altitude settlements, may have additional detrimental effects on patients with HAPH and may further alter the MPs profile. According to our hypotheses, we will address the following questions:
1) What is the expression level of various endothelial and inflammatory cell-derived MPs in the peripheral blood of Kyrgyz highlanders with or without HAPH compared to the low-land control group? Is there any influence of the cold exposure on MP expression profiles in different patient groups?, and
2) In order to characterize whether MPs are promising biomarkers, is there a correlation between circulating MP levels and clinical parameters measured by echocardiography, such as systolic pulmonary arterial pressure (PAP), mean PAP, pulmonary artery acceleration time (PAAT), cardiac index (CI) and pulmonary vascular resistance (PVR) in different human subject groups?
John H. Newman, M.D. and Stuart Rich, M.D.
An ongoing multifaceted project that will create a template for a precision medicines approach that will be used for new drugs. A workshop including the NHLBI and FDA initiated the process. To follow will be the designation of a task force that will have several working groups develop guidelines for the different facets of clinical trials. Guidelines for phase II clinical trials in this field will be created and disseminated. An initial project that will seek to identify a unique phenotype of patients that may be responsive to a select tyrosine kinase inhibitor will be conducted. This will be followed by a proof-of-concept clinical study using the precision medicine approach.
Eric D. Austin
Aim 1: To establish a biospecimen respository linked to the meticulously phenotyped PPHNet patient and family cohort. The PPHNet BiOspecimen Laboratory Depot (PPHNet-BOLD) will provide a resource of DNA, RNA, plasma, serum, and circulating peripheral blood mononuclear cells for investigators studying pediatric PH. Based upon current PPHNet enrollment numbers, we anticipate over 200 subjects per year including over 50 new PH diagnoses. PPHNet-BOLD will be housed at All Children’s Hospital Johns Hopkins Medicine, and overseen by the PPHNet Steering Committee.
Aim 2: To determine the frequency of known PH-associated gene mutations in pediatric PH. We will use next generation sequencing coupled with MLPA to comprehensively screen for mutations in the BMPR2, SMAD9, CAV1, KCNK3, ALK1, ENG, EIF2AK4 genes. This approach should detect not only point mutations and small insertions/deletions, but also exonic deletions and duplications in the genes of interest and add critical information to frame the detailed clinical outcomes already captured by the PPHNet.
Aim 3: To promote and distribute samples and genotype/sequence data maintained at the PPHNet-BOLD repository. All biological samples, clinical data, as well as the PH-specific sequencing data for these subjects will be made available to the scientific community. A small review committee comprised of investigators from PPHNet contributing centers to the repository will review proposals requesting any samples and/or genotype data. Upon approval and after successful execution of a material transfer agreement (MTA), any requested samples will be supplied to the approved investigators.
The impact of this resource on the study of pediatric PH will be highly significant. We will create a resource of biological samples and data that will benefit every investigator interested in pursuing pediatric PH-related research. The proposed resource has generated tremendous support not only from the PPHNet enrolling centers, but from many centers which hope to join the PPHNet collaborative.
A grant to support the development and implementation of the PHA Patient Registry that will serve as a resource to help find ways to prevent and cure pulmonary hypertension.
SPECIFIC AIM #1: Measure and improve quality of care
SPECIFIC AIM #2: Understand risk factors for outcomes in PAH and CTEPH patients
SPECIFIC AIM #3: Facilitate funded clinical research studies in PAH/CTEPH
Pulmonary Vascular Research Institute
A grant in support of the launch of Pulmonary Circulation, the first peer reviewed scientific journal to publish original research articles, review articles, case report, and guidelines that are related to the pulmonary circulation, pulmonary vascular disease and lung injury.
This conference examined the interaction between the right ventricle and the pulmonary circulation as it occurs during development, in normal physiology and in disease states, notably pulmonary hypertension and congenital heart disease. The goal of this conference is to bring basic and translational scientists and physicians who deal with the pulmonary circulation and the right ventricle together to discuss the normal and disordered mechanisms by which the RV and pulmonary circulation are coupled.
A proposal to undertake a multiple approach in order to unveil actual characteristics of granulomas in the lung to systematically evaluate the number and cross-sectional distribution of inflammatory cells in different sizes of pulmonary arteries from the lungs of mice infected with schistosomiasis after 8 and 12 weeks and developed pulmonary vascular remodeling versus control uninfected healthy lungs.
This project aims to Identify treatment targets to abrogate pulmonary vascular fibrosis.
SA1: Demonstrate that NEDD9 accumulation defines maladaptive fibrosis in PAECs in vitro.
Hypothesis: Increased reactive oxygen species generation stimulated by ALDO occurring in PAECs promotes NEDD9 cysteinyl thiol oxidation and prevents NEDD9 degradation by Smad3 to sustain TGF-ß1-mediated collagen formation, which is a defining molecular mechanism of maladaptive fibrosis.
(1) Characterize the oxidant stress and NEDD9 expression profile differences in [ALDO-treated PAECs and dermal microvascular endothelial cells (DMVECs) in vitro, which are cell types associated with pathogenic and physiologic fibrosis, respectively.
(2) Use proteomics and Raman spectroscopy to characterize NEDD9 cysteinyl thiol oxidation states in PAECs and DMVECs, and the derivative consequences on NEDD9-Smad3 binding.
(3) Demonstrate that by inhibiting TGF-ß1 signaling through NEDD9 antagonism with NEDD9-siRNA, fibrillar collagen synthesis is attenuated in ALDO-treated PAECs.
SA2: Establish that NEDD9 contributes to pulmonary vascular fibrosis and PAH in vivo.
Hypothesis: Upregulation of pulmonary endothelial NEDD9 functions as a critical molecular lynchpin regulating pulmonary vascular fibrosis in vivo, which in PAH promotes cardiopulmonary dysfunction.
(1) Treat Sugen-5416/hypoxia-PAH rats, which express hyperALDO, with aerosolized NEDD9-siRNA or vehicle to demonstrate that molecular inhibition of NEDD9 attenuates maladaptive pulmonary vascular fibrosis to maintain/restore normal right ventricular (RV)-pulmonary arterial physiology (i.e., RV-pulmonary arterial coupling) and improve exercise capacity in PAH in vivo.
(2) Demonstrate definitively NEDD9 involvement in the development of pulmonary hypertension and pulmonary vascular fibrosis by analyzing pulmonary vascular histopathological changes and cardiopulmonary hemodynamics in transgenic NEDD9-/- mice exposed to hypoxia.
This will be a data repository and sharing platform for clinical trials in pulmonary hypertension, both previous and future. The long-term goal of this initiative is to accelerate the development of more effective treatments for PH by collecting and curating data from prior (and future) clinical trials of drugs, medical devices, management strategies, and biologics performed by academic investigators and industry. The deliverables of this initiative would include the:
1) Deep phenotyping of clinical trial participants to determine a more personalized approach to treatment, which could target certain treatments to patients with a higher chance of response (or avoid such treatments in patients with a greater risk of adverse events)
2) Ability to identify important and novel factors of disease progression and survival
3) Leveraging of biomarkers collected in the setting of the parent studies to guide treatment and to validate novel end points for future clinical trials
4) Creation of a “master” data infrastructure which could expedite future clinical trials in PH and facilitate harmonization
A symposium to discuss recent trends of integrating all branches of research on high-altitude and bring them to a common global platform for long term future perspectives.
Pulmonary Vascular Research Institute
The goal of these symposiums is to bring together the essential stakeholders (academia, industry, and regulatory) to present and critique the latest discoveries of treatments for pulmonary vascular diseases.
This project showed that the entropy of the first sinusoid formant at the 2nd LICS was significantly lower in subjects with PAH, yielding a classification into PAH and normal with a sensitivity of 93% and specificity of 92%. The reduced entropy of the first sinusoid formant of the heart sounds in subjects with PAH reveals an organized pattern in heart sounds. The analysis of this pattern revealed a unique sound signature produced by the hypertensive pulmonary artery and right ventricle, which can be captured and used to diagnose PAH
This study is designed to serve the objectives of (i) finding the association of HIF1AN and EGLN1 variants with HA adaptation and maladaptation, (ii) to find interactions between them and (iii) the various correlations between these two hydroxylases and other biomarkers like NO and ROS. Further, (iv) the methylation study will add to understanding the epigenetic role.
This project studied how the RV fails both by imaging it with radioactive glucose and fat metabolites, by cell studies and by a small trial of a drug called ranolazine that may have some benefit in oxygen starved muscle. New areas of interest in PH were pursued including a new class of RNA modulating nucleotides called microRNA, and stem cells were cultured from patients to get a better idea of basic cellular metabolic behavior.
Research includes mutational analysis of the genes BMPR2, ALK1, ENG and SMAD9, including sequencing of all coding regions and intron-exon boundaries, together with dosage analysis to detect larger genomic rearrangements.
Research on modifying the existing design of the partial support LVAD as an RVAD for refractory heart failure in advanced pulmonary hypertension.
Pulmonary Hypertension Association
Creation of a pediatric medical education of enduring value for pulmonary hypertension to honor Dr. Robyn Barst. Included in the project are CME accredited courses, case studies, the development of a pediatric resource center, an oral history of development of the field and a webinar series. All programs were integrated into PHA’s new Online University website, www.phaonlineuniv.org.
A 5 year unrestricted grant to support the mission of this unique professional organization as it expands its educational, scientific, and global outreach in pulmonary vascular diseases.