scholarly journals Epigenetic Mechanisms as Emerging Therapeutic Targets and Microfluidic Chips Application in Pulmonary Arterial Hypertension

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 170
Author(s):  
Linh Ho ◽  
Nazir Hossen ◽  
Trieu Nguyen ◽  
Au Vo ◽  
Fakhrul Ahsan
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Vascular Remodeling ◽  
Right Heart Failure ◽  
Cell Types ◽  
Epigenetic Mechanisms ◽  
Microfluidic Chips ◽  
Transcriptional Responses ◽  
Pulmonary Arterial ◽  
Epigenetic Regulators

Pulmonary arterial hypertension (PAH) is a disease that progress over time and is defined as an increase in pulmonary arterial pressure and pulmonary vascular resistance that frequently leads to right-ventricular (RV) failure and death. Epigenetic modifications comprising DNA methylation, histone remodeling, and noncoding RNAs (ncRNAs) have been established to govern chromatin structure and transcriptional responses in various cell types during disease development. However, dysregulation of these epigenetic mechanisms has not yet been explored in detail in the pathology of pulmonary arterial hypertension and its progression with vascular remodeling and right-heart failure (RHF). Targeting epigenetic regulators including histone methylation, acetylation, or miRNAs offers many possible candidates for drug discovery and will no doubt be a tempting area to explore for PAH therapies. This review focuses on studies in epigenetic mechanisms including the writers, the readers, and the erasers of epigenetic marks and targeting epigenetic regulators or modifiers for treatment of PAH and its complications described as RHF. Data analyses from experimental cell models and animal induced PAH models have demonstrated that significant changes in the expression levels of multiple epigenetics modifiers such as HDMs, HDACs, sirtuins (Sirt1 and Sirt3), and BRD4 correlate strongly with proliferation, apoptosis, inflammation, and fibrosis linked to the pathological vascular remodeling during PAH development. The reversible characteristics of protein methylation and acetylation can be applied for exploring small-molecule modulators such as valproic acid (HDAC inhibitor) or resveratrol (Sirt1 activator) in different preclinical models for treatment of diseases including PAH and RHF. This review also presents to the readers the application of microfluidic devices to study sex differences in PAH pathophysiology, as well as for epigenetic analysis.

Abstract 14880: Single-cell Transcriptomes Identify Unique Endothelial Subpopulation (FABP4 + TMEM100 - ) With Lipid Metabolism Dysfunction in Pulmonary Arterial Hypertension

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
BIN LIU ◽  
Jingbo Dai ◽  
Li Shuai ◽  
Dan Yi ◽  
Youyang Zhao ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Single Cell ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Premature Death ◽  
Right Heart Failure ◽  
Fatty Acid Binding ◽  
Pulmonary Arterial ◽  
Endothelial Plasticity

Introduction: Pulmonary arterial hypertension (PAH) is a disaster disease characterized by obliterative vascular remodeling and persistent increase of vascular resistance, leading to right heart failure and premature death. Understanding the cellular and molecular mechanisms will help develop novel therapeutic approaches for PAH patients. Hypothesis: We hypothesis that endothelial plasticity or distinct cell populations are critical for obstructive vascular remodeling in the pathogenesis of PAH. Methods: Here we applied single-cell RNA sequencing (ScRNA-seq) to profile the pulmonary cells in a severe mouse model ( Egln1 Tie2Cre mice) of PAH. Human hPAEC from idiopathic PAH patients and healthy donors were used to measure FABP4 and FABP5 expression. siRNA mediated knockdown of FABP4 and FABP5 was performed to study cell proliferation and apoptosis. Mice with Fabp4 and Fabp5 deletion ( Fabp45 -/- ) and wild type (WT) mice were incubated with hypoxia (10% O 2 ) to induced PAH. Egln1 Tie2Cre mice were bred with Fabp45 -/- mice to generate Egln1 Tie2Cre / Fabp45 -/- mice. Results: We identified five distinct EC subpopulations in both WT and Egln1 Tie2Cre mice via scRNA-seq. Unexpectedly, the number of Cluster (EC2, 49.8%) was markedly increased in Egln1 Tie2Cre lung compared with WT lung (2.8%). EC2 cluster (mainly from Egln1 Tie2Cre lung) was characterized by little expression of Tmem100 , Cldn5 , Tspan7 , Calcrl and Foxf1 and high expression of Fabp4, Cdh13, Sparl1 and Fabp5 . Fatty acid-binding protein (FABP) 4 and FABP5 (FABP4-5) were highly induced in PAECs from IPAH patients. Knockdown of FABP4-5 reduced EC proliferation and starvation-induced Caspase 3/7 activity. Fabp45 -/- mice were protected from hypoxia-induced PAH compared to WT mice. Moreover, Egln1 Tie2Cre / Fabp45 -/- mice also exhibited a reduction of RVSP and RV hypertrophy compared to Egln1 Tie2Cre mice. Conclusions: ScRNA-seq analysis identifies a unique endothelial population (FABP4 + TMEM100 - ) highly enriched in the lung of severe PAH mice. Knockdown of FABP4-5 reduces EC proliferation starvation-induced injury. Genetic deletion of FABP4-5 protects from hypoxia and Egln1 deficiency-induced PAH in mice.

scholarly journals Endothelial Nox1 oxidase assembly in human pulmonary arterial hypertension; driver of Gremlin1-mediated proliferation

2017 ◽  
Vol 131 (15) ◽  
pp. 2019-2035 ◽  
Author(s):  
Imad Al Ghouleh ◽  
Sanghamitra Sahoo ◽  
Daniel N. Meijles ◽  
Jefferson H. Amaral ◽  
Daniel S. de Jesus ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Therapeutic Option ◽  
Right Heart Failure ◽  
Pulmonary Vessel ◽  
Amplex Red ◽  
Endothelial Proliferation ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a rapidly degenerating and devastating disease of increased pulmonary vessel resistance leading to right heart failure. Palliative modalities remain limited despite recent endeavors to investigate the mechanisms underlying increased pulmonary vascular resistance (PVR), i.e. aberrant vascular remodeling and occlusion. However, little is known of the molecular mechanisms responsible for endothelial proliferation, a root cause of PAH-associated vascular remodeling. Lung tissue specimens from PAH and non-PAH patients and hypoxia-exposed human pulmonary artery endothelial cells (ECs) (HPAEC) were assessed for mRNA and protein expression. Reactive oxygen species (ROS) were measured using cytochrome c and Amplex Red assays. Findings demonstrate for the first time an up-regulation of NADPH oxidase 1 (Nox1) at the transcript and protein level in resistance vessels from PAH compared with non-PAH patients. This coincided with an increase in ROS production and expression of bone morphogenetic protein (BMP) antagonist Gremlin1 (Grem1). In HPAEC, hypoxia induced Nox1 subunit expression, assembly, and oxidase activity leading to elevation in sonic hedgehog (SHH) and Grem1 expression. Nox1 gene silencing abrogated this cascade. Moreover, loss of either Nox1, SHH or Grem1 attenuated hypoxia-induced EC proliferation. Together, these data support a Nox1-SHH-Grem1 signaling axis in pulmonary vascular endothelium that is likely to contribute to pathophysiological endothelial proliferation and the progression of PAH. These findings also support targeting of Nox1 as a viable therapeutic option to combat PAH.

scholarly journals New mechanisms of pulmonary arterial hypertension: role of Ca2+ signaling

2012 ◽  
Vol 302 (8) ◽  
pp. H1546-H1562 ◽  
Author(s):  
Frank K. Kuhr ◽  
Kimberly A. Smith ◽  
Michael Y. Song ◽  
Irena Levitan ◽  
Jason X-J. Yuan
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Vascular Remodeling ◽  
Right Heart Failure ◽  
Altered Expression ◽  
Pulmonary Vascular Remodeling ◽  
Advanced Stages ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a severe and progressive disease that usually culminates in right heart failure and death if left untreated. Although there have been substantial improvements in our understanding and significant advances in the management of this disease, there is a grim prognosis for patients in the advanced stages of PAH. A major cause of PAH is increased pulmonary vascular resistance, which results from sustained vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness. In addition to other signal transduction pathways, Ca2+ signaling in pulmonary artery smooth muscle cells (PASMCs) plays a central role in the development and progression of PAH because of its involvement in both vasoconstriction, through its pivotal effect of PASMC contraction, and vascular remodeling, through its stimulatory effect on PASMC proliferation. Altered expression, function, and regulation of ion channels and transporters in PASMCs contribute to an increased cytosolic Ca2+ concentration and enhanced Ca2+ signaling in patients with PAH. This review will focus on the potential pathogenic role of Ca2+ mobilization, regulation, and signaling in the development and progression of PAH.

Abstract 17034: The AKT/AMPK/FOXO3 Axis in Pulmonary Arterial Hypertension

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yann Grobs ◽  
Charlotte romanet ◽  
Valerie Nadeau ◽  
Junichi Omura ◽  
Mark Orcholski ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Vascular Remodeling ◽  
Pulmonary Arteries ◽  
Right Heart Failure ◽  
Metabolic Reprogramming ◽  
Nuclear Exclusion ◽  
Pulmonary Arterial

Like cancer, pulmonary arterial hypertension (PAH) is characterized by exaggerated proliferation and resistance to apoptosis related to metabolic alterations (Warburg effect) of pulmonary smooth muscle cells (PASMCs). These anomalies result in a progressive narrowing of the pulmonary arteries, increasing pulmonary resistance and leading to right heart failure and premature death. In cancer cells, unphosphorylated and nuclear FOXO3 has been extensively studied as a crucial protein that functions as a tumor suppressor by regulating expression of genes involved in apoptosis and cell cycle arrest. These functions combined with other FOXO3 attributes, including its key role in communicating mitochondrial-nuclear signals, make the FOXO3 a suitable candidate for controlling the cancer-like phenotype of PAH-PASMCs. Interestingly, AKT and AMPK known to be implicated in PAH exert antagonistic effects on FOXO3; AKT promoting its nuclear exclusion while AMPK favors its nuclear and mitochondrial accumulation. The thus made the hypothesis that FOXO3’s nuclear exclusion (secondary to AKT/AMPK imbalance) promotes metabolic reprogramming towards glycolysis leading to enhanced proliferation/resistance to apoptosis of PAH-PASMCs and vascular remodeling. Using Western blot and immunofluorescence in isolated PASMCs from both PAH and control patients (n=10), we found that nuclear and mitochondrial exclusion of FOXO3 due to its phosphorylation is a feature of PAH-PASMCs. In vitro, we demonstrated that nuclear localization of FOXO3 using an adenovirus expressing a constitutively active, non-phosphorylable form of FOXO3 or trifluoperazine (TFP) resulted in reduced PAH-PASMC proliferation (Ki67 labeling, p<0,0005) and resistance to apoptosis (Annexin V assay, p<0,05). These effects were accompanied by increased expression of P27 and SOD2 and diminished expression of Survivin (p<0,05). In vivo, we showed that FOXO3 activation using TPF improved established PAH in the monocrotaline rats (reduced RVSP and increased Sv and CO, by right catheterization, p<0,01, n=29) without any sign of toxicity. We showed that FOXO3 is implicated in pulmonary vascular remodeling. Pharmacological activation of FOXO3 may represent a novel avenue to improve PAH.

Endothelial Cells in the Pathogenesis of Pulmonary Arterial Hypertension

2021 ◽  
pp. 2003957
Author(s):  
Colin E. Evans ◽  
Nicholas D. Cober ◽  
Zhiyu Dai ◽  
Duncan J. Stewart ◽  
You-Yang Zhao
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Cell Signalling ◽  
Premature Death ◽  
Right Heart Failure ◽  
Cell Types ◽  
Pulmonary Vasoconstriction ◽  
Nitrative Stress ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is a devastating disease that involves pulmonary vasoconstriction, small vessel obliteration, large vessel thickening and obstruction, and development of plexiform lesions. PAH vasculopathy leads to progressive increases in pulmonary vascular resistance, right heart failure, and ultimately, premature death. Besides other cell types that are known to be involved in PAH pathogenesis (e.g. smooth muscle cells, fibroblasts, and leukocytes), recent studies demonstrate a crucial role of endothelial cells (ECs) in the initiation and progression of PAH. The EC-specific role in PAH is multi-faceted and impacts upon numerous pathophysiological processes including vasoconstriction, inflammation, coagulation, metabolism, and oxidative/nitrative stress, as well as cell viability, growth, and differentiation. In this review, we describe how EC dysfunction and cell signalling regulate the pathogenesis of PAH. We also highlight areas of research that warrant attention in future studies, and discuss potential molecular signalling pathways in ECs that could be targeted therapeutically in the prevention and treatment of PAH.

Model Characterization of Pulmonary Arterial Hypertension: Analysis of Lung Pathology with Respect to Human Disease

2020 ◽  
Author(s):  
◽  
Eptisam lambu
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Human Disease ◽  
Vascular Remodeling ◽  
Vascular Wall ◽  
Lung Pathology ◽  
Pulmonary Arterial ◽  
Lung Pathogenesis ◽  
Arterial Endothelial Cells

Pulmonary arterial hypertension (PAH) is a rare multifactorial disease characterized by abnormal high blood pressure in the pulmonary artery, or increased pulmonary vascular resistance (PVR), caused by obstruction in the small arteries of the lung. Increased PVR is also thought to be caused by abnormal vascular remodeling, due to thickening of the pulmonary vascular wall resulting from significant hypertrophy of pulmonary arterial smooth-muscle cells (PASMCs) and increased proliferation/impaired apoptosis of pulmonary arterial endothelial cells (PAECs). Herein, we investigated the mechanisms and explored molecular pathways mediating the lung pathogenesis in two PAH rat models: Monocrotaline (MCT) and Sugen5416/Hypoxia (SuHx). We analyzed these disease models to determine where the vasculature shows the most severe PAH pathology and which model best recapitulates the human disease. We investigated the role vascular remodeling, hypoxia, cell proliferation, apoptosis, DNA damage and inflammation play in the pathogenesis of PAH. Neither model recapitulated all features of the human disease, however each model presented with some of the pathology seen in PAH patients.

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