Project description:Samples surgically extracted from CTEPH pulmonary arteries were compared to post-transplant pulmonary arteries from IPAH and failed donor pulmonary arteries from controls The goal was to determine if altered gene expression in CTEPH associated with development of chronic thrombi
Project description:The hallmark of chronic thromboembolic pulmonary hypertension (CTEPH) is fibrotic transformation of pulmonary arterial thrombus, leading to mechanical obstruction of pulmonary arteries. We report the transcriptome profile of fibroblasts isolated from pairs of CTEPH thrombus and pulmonary artery adventitia of the same patient. Fibroblasts isolated from CTEPH thrombus demonstrated upregulation of genes associated with the TGF-β pathway indicating that TGF-β upregulation is associated with the intravascular remodeling process.
Project description:Idiopathic Pulmonary Arterial Hypertension (IPAH) is a severe human disease, characterized by extensive pulmonary vascular remodeling due to plexiform and obliterative lesions, media hypertrophy, and alterations of adventitia. The objective of the study was to test the hypothesis that microscopic IPAH vascular lesions express unique molecular profiles, which collectively are different from control pulmonary arteries. We used digital spatial transcriptomics to profile the genome-wide differential transcriptomic signature of key pathological lesions (plexiform, obliterative, intima+media hypertrophy, and adventitia) in IPAH lungs (n= 11) and compared these data to the intima+media and adventitia of control pulmonary artery (n=5). The IPAH lesions and pulmonary artery compartments were defined by the analyses of hematoxylin-eosin stained serial section, aided by labeling with CD31 (for endothelial cells), smooth muscle cell actin (SMA), and CD45 for inflammatory mononuclear cells, also in serial sections. Approximately 12 regions of interest (ROI) were sampled from a histological section of a paraffin-embedded block of each lung, which was selected based on the finding of enrichment for IPAH lesions or control pulmonary arteries.
Project description:Pulmonary hypertension worsens outcome in left heart disease. Stiffening of the pulmonary artery may drive this pathology by increasing right ventricular dysfunction and lung vascular remodeling. We showed that pulmonary arteries from patients with left heart disease are characterized by increased stiffness that correlates with impaired pulmonary hemodynamics. Pulmonary arteries in left heart disease patients with pulmonary hypertension were characterized by degradation of elastic fibers paralleled by an accumulation of fibrillar collagens. We utilized RNA sequencing to identify differentially expressed genes regulating extracellular matrix remodeling in pulmonary arteries of left heart disease patients with or without pulmonary hypertension, in comparison to healthy-heart donor controls. As such we identified that transcriptional deregulation of extracellular matrix constituents and their regulators precedes clinical pulmonary hypertension, and therefore might be a pathomechanism that drives pulmonary arterial remodeling and stiffening in left heart disease.
Project description:Our current understanding of CTEPH pathobiology is primarily derived from cell-based studies limited by the use of specific cell markers or phenotypic modulation in cell culture. Therefore, our main objective is to identify the multiple cell types that comprise the CTEPH thrombus and to study their dysfunction. Here we used single cell RNA sequencing (scRNAseq) of tissue removed at the time of pulmonary endarterectomy (PEA) surgery from five patients to identify the multiple cell types. Our scRNAseq identify the multiple cell types including macrophages, T cells, and smooth muscle cells, that comprise CTEPH thrombus. Notably, multiple macrophage subclusters were identified but broadly split into two categories, with the larger group characterized by an upregulation of inflammatory signaling predicted to promote pulmonary vascular remodeling. Both CD4+ and CD8+ T cells were identified and likely contribute to chronic inflammation in CTEPH. Smooth muscle cells were a heterogeneous population, with a cluster of myofibroblasts that express markers of fibrosis and are predicted to arise from other smooth muscle cell clusters based on pseudotime analysis. Lastly, our analysis identified protease-activated receptor 1 (PAR1) as a potential therapeutic target that links thrombosis to chronic PE in CTEPH
Project description:The aim of this study was to determine whether extracellular vesicle (EV)-associated small non-coding RNAs (sncRNAs) have potential as biomarkers for chronic thromboembolic pulmonary hypertension (CTEPH). EVs were isolated using different methods from serum of 23 CTEPH patients and 23 controls. EV-associated RNAs were analysed by next-generation sequencing using the TrueQuant method for molecular barcoding, and differentially expressed sncRNAs were validated by qRT-PCR. We identified 18 miRNAs and 21 piRNAs or piRNA clusters that were differentially expressed in CTEPH patients compared with the control group. Bioinformatic analysis predicted a contribution of these piRNAs to the progression of cardiac and vascular remodelling. Furthermore, the expression levels of DQ593039 correlated with clinically meaningful parameters such as mean pulmonary arterial pressure, pulmonary vascular resistance, right ventricular systolic pressure, and levels of N-terminal pro-brain natriuretic peptide. In summary, EV-associated piRNA DQ593039 shows promise as biomarker and may be a potential therapeutic target for CTEPH.
Project description:Chronic thromboembolic pulmonary hypertension (CTEPH) is a group 4 pulmonary hypertension (PH) characterized by non-resolving thromboembolism in the central pulmonary artery and vascular occlusion in the proximal and distal pulmonary artery. Medical therapy is chosen for patients who are ineligible for pulmonary endarterectomy or balloon pulmonary angioplasty or who have symptomatic residual PH after surgery or intervention. Selexipag, an oral prostacyclin receptor agonist and potent vasodilator, was approved for CTEPH in Japan in 2021. To evaluate the pharmacological effect of selexipag on vascular occlusion in CTEPH, we examined how its active metabolite MRE-269 affects platelet-derived growth factor-stimulated pulmonary arterial smooth muscle cells (PASMCs) from CTEPH patients. MRE-269 showed a more potent anti-proliferative effect on PASMCs from CTEPH patients than on those from normal subjects. DNA-binding protein inhibitor genes ID1 and ID3 were found by RNA sequencing and real-time quantitative polymerase chain reaction to be expressed at lower levels in PASMCs from CTEPH patients than in those from normal subjects and were upregulated by MRE-269 treatment. ID1 and ID3 upregulation by MRE-269 was blocked by co-incubation with a prostacyclin receptor antagonist, and ID1 knockdown by small interfering RNA transfection attenuated the anti-proliferative effect of MRE-269. ID signaling may be involved in the anti-proliferative effect of MRE-269 on PASMCs. This is the first study to demonstrate the pharmacological effects on PASMCs from CTEPH patients of a drug approved for the treatment of CTEPH. Both the vasodilatory and the anti-proliferative effect of MRE-269 may contribute to the efficacy of selexipag in CTEPH.
Project description:Dysfunction of pulmonary arterial endothelial cells (PAECs) is associated with the development and progression of vascular pathology. However, it remains unknown how pulmonary hypertension (PH) affects cellular composition and transcriptomic profile of pulmonary endothelium. Here, we have undertaken a single-cell, compartment specific approach to characterise alterations in PAECs associated with two different types of PH, i.e., pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with pulmonary fibrosis (PHPF). Our unbiased analysis showed that endothelium of medium / small caliber pulmonary arteries is composed of three subsets of endothelial cells (ECs). The analysis of healthy and PH endothelium revealed that the three populations are persistently represented in remodelled arteries. Additionally, an exploratory analysis of human aorta (AO) and coronary arteries (CA) endothelium revealed that, although similar gene expression patterns were noticeable, PAECs subpopulations proportions differs significantly from pulmonary arteries (PA) endothelium. To address whether EC heterogeneity is a prime feature of human endothelium, we also performed a similar analysis in a murine model of hypoxia, revealing that similar EC populations were evident in this animal model. Comparative analysis of EC subpopulations in healthy and PH EC identified a common genetic deregulation accompanying vascular remodelling. Even though murine EC displayed some similarities with human EC subpopulations, the intense re-programming associated with hypoxia associated vascular remodelling displayed significant differences compared to the human disease. Finally, in depth comparative analysis of PAH and PHPF EC highlighted the development of disease-specific transcriptomic alterations in the three populations. Therefore, characterisation of transcriptomic differences in the endothelial bed of PAH and PHPF patients can facilitate identification of novel, disease-specific therapeutic targets.
Project description:Endothelial cells are implicated in delayed thrombus resolution. We use single cell RNA sequencing of CTEPH surgical specimens to assess endothelial cell phenotypes that contribute to delayed thrombus resolution.