Project description:Pulmonary hypertension (PH) is a common complication of systemic sclerosis (SSc) and a leading cause of mortality among patients with this disease. PH can also occur as an idiopathic condition (idiopathic pulmonary arterial hypertension, iPAH). We sought to investigate the transcriptomic alterations in PH vascular populations to understand cellular mechanisms underlying pathobiology of systemic sclerosis associated and idiopathic pulmonary hypertension.
Project description:Despite recent improvements in management of idiopathic pulmonary arterial hypertension, mortality remains high. Understanding the alterations in the transcriptome–phenotype of the key lung cells involved could provide insight into the drivers of pathogenesis. In this study, we examined differential gene expression of cell types implicated in idiopathic pulmonary arterial hypertension from lung explants of patients with idiopathic pulmonary arterial hypertension compared to control lungs. After tissue digestion, we analyzed all cells from three idiopathic pulmonary arterial hypertension and six control lungs using droplet-based single cell RNA-sequencing. After dimensional reduction by t-stochastic neighbor embedding, we compared the transcriptomes of endothelial cells, pericyte/smooth muscle cells, fibroblasts, and macrophage clusters, examining differential gene expression and pathways implicated by analysis of Gene Ontology Enrichment. We found that endothelial cells and pericyte/smooth muscle cells had the most differentially expressed gene profile compared to other cell types. Top differentially upregulated genes in endothelial cells included novel genes: ROBO4, APCDD1, NDST1, MMRN2, NOTCH4, and DOCK6, as well as previously reported genes: ENG, ORAI2, TFDP1, KDR, AMOTL2, PDGFB, FGFR1, EDN1, and NOTCH1. Several transcription factors were also found to be upregulated in idiopathic pulmonary arterial hypertension endothelial cells including SOX18, STRA13, LYL1, and ELK, which have known roles in regulating endothelial cell phenotype. In particular, SOX18 was implicated through bioinformatics analyses in regulating the idiopathic pulmonary arterial hypertension endothelial cell transcriptome. Furthermore, idiopathic pulmonary arterial hypertension endothelial cells upregulated expression of FAM60A and HDAC7, potentially affecting epigenetic changes in idiopathic pulmonary arterial hypertension endothelial cells. Pericyte/smooth muscle cells expressed genes implicated in regulation of cellular apoptosis and extracellular matrix organization, and several ligands for genes showing increased expression in endothelial cells. In conclusion, our study represents the first detailed look at the transcriptomic landscape across idiopathic pulmonary arterial hypertension lung cells and provides robust insight into alterations that occur in vivo in idiopathic pulmonary arterial hypertension lungs.
Project description:Pulmonary endothelial dysfunction plays an integral role in mediating the initiation and progression of pulmonary vascular remodelling, an important feature of pulmonary arterial hypertension (PAH). Our aim was to decipher the gene expression program of endothelial cells derived from circulating endothelial progenitor (EPCs) to gain insight into the pathological process of PAH associated with systemic sclerosis (SSc), which is the most extreme vascular phenotype of this disease. We used microarrays to investigate the gene expression profile in late outgrowth EPC-derived endothelial cells issued from SSc-PAH patients, in comparison with SSc patients without PAH and healthy controls.
Project description:The hypothesis tested in this study was that chronic exposure of PBMCs to a hypertensive environment in remodeled pulmonary vessels would be reflected by specific transcriptional changes in these cells. The transcript profiles of PBMCs from 30 idiopathic pulmonary arterial hypertension patients (IPAH), 19 patients with systemic sclerosis without pulmonary hypertension (SSc), 42 scleroderma-associated PAH patients (SSc-PAH), and 8 patients with SSc complicated by interstitial lung disease and PH (SSC-PH-ILD) were compared to the gene expression profiles of PBMCs from 41 healthy individuals. Gene expression is compared at a global level using total RNA from BPMC for pateints and controls using the Illumina microarray platform.
Project description:Human herpesvirus-8 (HHV-8) is the causative agent of Kaposiâs sarcoma and is associated with the angioproliferative disorders primary effusion lymphoma (PEL) and multicentric Castlemanâs disease (MCD). We have previously described evidence of HHV-8 infection within the pulmonary vasculature of patients with idiopathic pulmonary arterial hypertension (IPAH). We speculated that viral infection of the pulmonary microvascular endothelial cells could cause the angioproliferative phenotype characteristic of severe pulmonary arterial hypertension (PAH). We now demonstrate the ability of HHV-8 to infect human pulmonary microvascular endothelial cells (HPMVECs) in vitro, confirming both latent and lytic infection. HHV-8 infection of HPMVECs resulted in significant changes of gene expression including alterations of pathways integral to both cellular apoptosis and angiogenesis. This infection also results in alterations of genes integral to the bone morphogenic protein (BMP) pathway, including down regulation of bone morphogenic protein receptor 1a (BMPR1a) and bone morphogenic protein 4 (BMP4). Other genes previously implicated in the development of PAH are also altered in expression by HHV-8 infection. These include increased expression of Interleukin-6 (IL-6) and the matrix metalloproteinases (MMP)-1, MMP-2 and MMP-10. Lastly, cells infected with HHV-8 apoptosis resistant. Infection of pulmonary microvascular endothelial cells with human herepesvirus-8 results in alteration of the BMP pathway as well as an anti-apoptotic phenotype, consistent with the development of plexiform lesions characteristic of pulmonary arterial hypertension. Experiment Overall Design: ⢠Direct comparison of HHV8-infected and mock-infected human pulmonary microvascular endothelial cells. Experiment Overall Design: ⢠Triplicate infection and mock infection samples were prepared. One hybridization per sample, 6 total hybridizations Experiment Overall Design: ⢠Single channel hybridization (no reference).
Project description:Human herpesvirus-8 (HHV-8) is the causative agent of Kaposi’s sarcoma and is associated with the angioproliferative disorders primary effusion lymphoma (PEL) and multicentric Castleman’s disease (MCD). We have previously described evidence of HHV-8 infection within the pulmonary vasculature of patients with idiopathic pulmonary arterial hypertension (IPAH). We speculated that viral infection of the pulmonary microvascular endothelial cells could cause the angioproliferative phenotype characteristic of severe pulmonary arterial hypertension (PAH). We now demonstrate the ability of HHV-8 to infect human pulmonary microvascular endothelial cells (HPMVECs) in vitro, confirming both latent and lytic infection. HHV-8 infection of HPMVECs resulted in significant changes of gene expression including alterations of pathways integral to both cellular apoptosis and angiogenesis. This infection also results in alterations of genes integral to the bone morphogenic protein (BMP) pathway, including down regulation of bone morphogenic protein receptor 1a (BMPR1a) and bone morphogenic protein 4 (BMP4). Other genes previously implicated in the development of PAH are also altered in expression by HHV-8 infection. These include increased expression of Interleukin-6 (IL-6) and the matrix metalloproteinases (MMP)-1, MMP-2 and MMP-10. Lastly, cells infected with HHV-8 apoptosis resistant. Infection of pulmonary microvascular endothelial cells with human herepesvirus-8 results in alteration of the BMP pathway as well as an anti-apoptotic phenotype, consistent with the development of plexiform lesions characteristic of pulmonary arterial hypertension. Keywords: Viral infection of endothelial cells in culture
Project description:The hypothesis tested in this study was that chronic exposure of PBMCs to a hypertensive environment in remodeled pulmonary vessels would be reflected by specific transcriptional changes in these cells. The transcript profiles of PBMCs from 30 idiopathic pulmonary arterial hypertension patients (IPAH), 19 patients with systemic sclerosis without pulmonary hypertension (SSc), 42 scleroderma-associated PAH patients (SSc-PAH), and 8 patients with SSc complicated by interstitial lung disease and PH (SSC-PH-ILD) were compared to the gene expression profiles of PBMCs from 41 healthy individuals.
Project description:Limited systemic sclerosis patients with pulmonary arterial hypertension show biomarkers of inflammation and vascular injury Forty-nine PBMC samples were obtained from 21 lSSc subjects without PAH (lSSc-noPAH), 15 lSSc subjects with PAH (lSSc-PAH), and 10 healthy controls; three subjects provided PBMCs one year later. Genome-wide gene expression was measured for each sample. Gene expression clearly distinguished lSSc samples from healthy controls, and separated lSSc-PAH from lSSc-NoPAH patients. The gene expression and cytokine profiles of lSSc-PAH patients suggest the presence of activated monocytes, and show markers of vascular injury and inflammation. Sample vs reference, total RNA isolated from peripheral blood mononuclear cells (PBMC), 21 lSSc subjects without PAH (lSSc-noPAH), 15 lSSc subjects with PAH (lSSc-PAH), and 10 healthy controls
Project description:Pulmonary arterial hypertension (PAH) is a severe and incurable pulmonary vascular disease. One of the primary origins of PAH is pulmonary endothelial dysfunction leading to vasoconstriction, aberrant angiogenesis and smooth muscle cell proliferation, endothelial-to-mesenchymal transition, thrombosis and inflammation. Our objective was to study the epigenetic variations in pulmonary endothelial cells (PEC) through a specific pattern of DNA methylation. DNA was extracted from cultured PEC from patients with idiopathic PAH (n=11), heritable PAH (n=10) and controls (n=18). ). DNA methylation was assessed using the Illumina HumanMethylation450 Assay. After normalization, samples and probes were clustered according to their methylation profile. Differential clusters were functionally analysed using bioinformatics tools.