scholarly journals Metabolomics Based Mechanism Exploration of Pulmonary Arterial Hypertension pathogenesis: Novel Lessons from Explanted Lungs

Author(s):  
Jingjing Ding ◽  
Chunyan Chu ◽  
Zhengsheng Mao ◽  
Jiawen Yang ◽  
Jie Wang ◽  
...  

Abstract Background: Metabolic pathways have been shown to participate in the pathogenesis of pulmonary arterial hypertension (PAH). We investigated the metabolic profile shifts to reveal molecular mechanisms underlying PAH. Methods: Explanted human lung tissues from 18 PAH patients were collected. The lung tissues far from the tumor from 16 lung cancer patients were taken as controls. Lung tissues were analyzed by LC-MS/MS based non-target metabolomics method. Pathway analysis was performed with KEGG database and MetaboAnalyst 5.0. Statistical analysis including partial least squares discriminant analysis (PLS-DA), Student’s t-test, Pearson’s correlation, Chi-square test and Fisher’s exact probability test were used. COX survival analysis model was applied to evaluate the predictive value of metabolites on prognosis. Protein expression levels were detected by Western blotting in human PAH lung tissues, rat monocrotaline-PAH lungs and hypoxia exposed human pulmonary artery smooth muscle cells (HPASMCs) to study the molecular mechanisms.Results: Significant differences in metabolites and metabolic pathways were identified among PAH subgroups and control tissues. Spermine levels were positively correlated with the patients' cardiac outputs (COs). Levels of (2e)-2,5-dichloro-4-oxo-2-hexenedioic acid were positively correlated with the patient's serum creatinine (Scr) levels. Patients with higher levels of thymine had a better prognosis. Moreover, 7 differential metabolites were associated with AKT pathway. AKT pathway inactivation was confirmed in human and rat PAH lungs and hypoxia exposed HPASMCs.Conclusions: Our findings provide the first metabolomics evidence for PAH pathogenesis by human lungs and may contribute to the improvement of therapeutic strategy.

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Maha Abdalla ◽  
Anna Goc ◽  
Lakshman Segar ◽  
Payaningal R Somanath

Objectives Myofibroblast (MF) differentiation is marked by the de novo expression of smooth muscle alpha-actin (αSMA) stress fibers, a function critical for tissue repair both physiologically and pathophysiologically. However, the role of Akt in regulating MFs with implications in pulmonary arterial hypertension (PAH) and fibrosis, and the effect of pharmacological inhibition of Akt pathway on PAH and fibrosis remains poorly defined. Methods We used NIH 3T3 fibroblasts and primary human lung fibroblasts (HLFs) in the current study. Cells were treated with TGFβ, the profibrotic cytokine and the role of Akt, SRF and myocardin in αSMA expression, MF differentiation and collagen gel contraction was studied with the use of various constructs encoding expression of specific genes. Results Here, we show that Akt mediates MF differentiation as evident by a 5-fold increase in αSMA expression and assembly in mouse embryonic fibroblasts (NIH 3T3) over-expressing active Akt1 (myr-Akt). As for the molecular mechanisms governing MFs, we found that αSMA expression was mediated by Akt, independent of mTOR; noteworthy, fibronectin expression, an ECM protein, is Akt-mTOR dependent. Inhibiting Akt activation utilizing triciribine blunted αSMA and its transcriptional activators, myocardin and SRF, inhibiting MF differentiation in NIH 3T3, myr-Akt-NIH 3T3, and human lung fibroblasts. Furthermore, blocking Akt reversed MF differentiation as evident by a blunted gel contraction primed with TGFβ. Conclusions In conclusion, our study clearly demonstrates the crucial role of Akt in mediating TGFβ-induced MF differentiation. We show a previously uncharacterized link between Akt and TGFβ-induced αSMA synthesis through myocardin and SRF, independent of mTOR, in MFs. These data constitute evidence of novel signaling cascade and targeting Akt pathway might be beneficial for the treatment of PAH and fibrosis.


Author(s):  
Peiliang Wu ◽  
Xiaona Xie ◽  
Mayun Chen ◽  
Junwei Sun ◽  
Luqiong Cai ◽  
...  

Background and Objective: Qishen Yiqi formula (QSYQ) is used to treat cardiovascular disease in the clinical practice of traditional Chinese medicine. However, few studies have explored whether QSYQ affects pulmonary arterial hypertension (PAH), and the mechanisms of action and molecular targets of QSYQ for the treatment of PAH are unclear. A bioinformatics/network topology-based strategy was used to identify the bioactive ingredients, putative targets, and molecular mechanisms of QSYQ in PAH. Methods: A network pharmacology-based strategy was employed by integrating active component gathering, target prediction, PAH gene collection, network topology, and gene enrichment analysis to systematically explore the multicomponent synergistic mechanisms. Results: In total, 107 bioactive ingredients of QSYQ and 228 ingredient targets were identified. Moreover, 234 PAH-related differentially expressed genes with a |fold change| >2 and an adjusted P value < 0.005 were identified between the PAH patient and control groups, and 266 therapeutic targets were identified. The pathway enrichment analysis indicated that 85 pathways, including the PI3K-Akt, MAPK, and HIF-1 signaling pathways, were significantly enriched. TP53 was the core target gene, and 7 other top genes (MAPK1, RELA, NFKB1, CDKN1A, AKT1, MYC, and MDM2) were the key genes in the gene-pathway network based on the effects of QSYQ on PAH. Conclusion: An integrative investigation based on network pharmacology may elucidate the multicomponent synergistic mechanisms of QSYQ in PAH and lay a foundation for further animal experiments, human clinical trials and rational clinical applications of QSYQ.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
BIN LIU ◽  
Jingbo Dai ◽  
Li Shuai ◽  
Dan Yi ◽  
Youyang Zhao ◽  
...  

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.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Katie Y Hood ◽  
Augusto C Montezano ◽  
Margaret R MacLean ◽  
Rhian M Touyz

Women develop pulmonary arterial hypertension (PAH) more frequently than men. This may relate, in part, to metabolism of 17β-estradiol (E2), leading to formation of the deleterious metabolite, 16α-hydroxyestrone (16α OHE1), which plays a role in the remodelling of pulmonary arteries. Molecular mechanisms whereby 16αOHE1 influences PASMC remodelling are unclear but ROS may be important, since oxidative stress has been implicated in the pathogenesis of PAH. We hypothesised that E2 and 16αOHE1 leads to Nox-induced ROS production, which promotes PASMC damage. Cultured PASMCs were stimulated with either E2 (1nM) or 16αOHE1 (1nM) in the presence/absence of EHT1864 (100μM, Rac1 inhibitor) or tempol (antioxidant; 10μM). ROS production was assessed by chemiluminescence (O2-) and Amplex Red (H2O2). Antioxidants (thioredoxin, peroxiredoxin 1 and NQ01), regulators of Nrf2 (BACH1, Nrf2) and, marker of cell growth (PCNA) were determined by immunoblotting. E2 increased O2- production at 4h (219 ± 30% vs vehicle; p<0.05), an effect blocked by EHT1864 and tempol. E2 also increased H2O2 generation (152 ± 4%; p<0.05). Thioredoxin, NQ01 and peroxiredoxin1 (71 ± 6%; 78 ± 9%; 69 ± 8%; p<0.05 respectively) levels were decreased by E2 as was PCNA expression (72 ± 2%; p<0.05). 16αOHE1 exhibited a rapid (5 min) and exaggerated increase in ROS production (355 ± 41%; p<0.05), blocked by tempol and EHT1864. This was associated with an increase in Nox4 expression (139 ± 11% vs vehicle, p<0.05). 16αOHE1 increased BACH1, (129 ± 3%; p<0.05), a competitor of Nrf2, which was decreased (92 ± 2%). In contrast, thioredoxin expression was increased by 16aOHE1 (154 ± 22%; p<0.05). PCNA (150 ± 5%) expression was also increased after exposure to 16αOHE1. In conclusion, E2 and 16αOHE1 have differential effects on redox processes associated with PASMC growth. Whereas E2 stimulates ROS production in a slow and sustained manner without effect on cell growth, 16αOHE1 upregulates Nox4 with associated rapid increase in ROS generation and downregulation of antioxidant systems, affecting proliferation. Our findings suggest that E2 -derived metabolites may promote a pro-proliferative PASMC phenotype through Nox4-derived ROS generation. These deleterious effects may impact on vascular remodeling in PAH.


2019 ◽  
Vol 9 (1) ◽  
pp. 204589401983489 ◽  
Author(s):  
Meghan M. Cirulis ◽  
John J. Ryan ◽  
Stephen L. Archer

Arrhythmias are increasingly recognized as serious, end-stage complications of pre-capillary pulmonary hypertension, including pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Although arrhythmias contribute to symptoms, morbidity, in-hospital mortality, and possibly sudden death in PAH/CTEPH, there remains a paucity of epidemiologic, pathophysiologic, and outcome data to guide management of these patients. This review summarizes the most current evidence on the topic: from the molecular mechanisms driving arrhythmia in the hypertrophied or failing right heart, to the clinical aspects of epidemiology, diagnosis, and management.


2010 ◽  
Vol 298 (4) ◽  
pp. L483-L491 ◽  
Author(s):  
Mirjam E. van Albada ◽  
Beatrijs Bartelds ◽  
Hans Wijnberg ◽  
Saffloer Mohaupt ◽  
Michael G. Dickinson ◽  
...  

Pulmonary arterial hypertension (PAH) is a pulmonary angioproliferative disease with high morbidity and mortality, characterized by a typical pattern of pulmonary vascular remodeling including neointimal lesions. In congenital heart disease, increased pulmonary blood flow has appeared to be a key mediator in the development of these characteristic lesions, but the molecular mechanisms underlying the pulmonary vascular lesions are largely unknown. We employed a rat model of flow-associated PAH, which induced specific pulmonary neointimal lesions. We identified gene expression profiles in rats specifically related to the addition of increased pulmonary blood flow to monocrotaline and the associated occurrence of neointimal lesions. Increased pulmonary blood flow induced the expression of the transcription factors activating transcription factor-3 (ATF3) and early growth response factor-1 (EGR-1), for which presence was confirmed in neointimal lesions. Monocrotaline alone induced increased numbers of activated mast cells and their products. We further identified molecular pathways that may be involved in treatment with the prostacyclin analog iloprost, a vasoactive compound with clinically beneficial effects in patients with PAH, which were similar to pathways described in samples from patient studies. These pathways, associated with the development of angioproliferative lesions as well as with the response to therapy in PAH, may provide new therapeutic targets.


2021 ◽  
Vol 12 ◽  
pp. 204062232110473
Author(s):  
Xiaohan Qin ◽  
Tianhao Li ◽  
Wei Sun ◽  
Xiaoxiao Guo ◽  
Quan Fang

Pulmonary arterial hypertension (PAH) is a rare but fatal cardiovascular disorder with high morbidity and mortality. Diagnosis and treatment of this disease at an early stage would greatly improve outcomes. The molecular indicators of PAH are mostly nonspecific, and diagnostic and prognostic biomarkers are urgently needed. A more comprehensive understanding of the molecular mechanisms underlying this complex disease is crucial for the development of new and more effective therapeutics to improve patient outcomes. In this article, we review published literature on proteomic biomarkers and underlying molecular mechanisms in PAH and their value for disease management, aiming to deepen our understanding of the disease and, ultimately, pave the way for clinical application.


Author(s):  
Thibault R. H. Jouen-Tachoire ◽  
Stephen J. Tucker ◽  
Paolo Tammaro

Pulmonary arterial hypertension (PAH) is a fatal disease of the cardiopulmonary system that lacks curative treatments. The main pathological event in PAH is elevated vascular resistance in the pulmonary circulation, caused by abnormal vasoconstriction and vascular remodelling. Ion channels are key determinants of vascular smooth muscle tone and homeostasis, and four PAH channelopathies (KCNK3, ABCC8, KCNA5, TRPC6) have been identified so far. However, the contribution of ion channels in other forms of PAH, which account for the majority of PAH patients, has been less well characterised. Here we reason that a variety of triggers of PAH (e.g. BMPR2 mutations, hypoxia, anorectic drugs) that impact channel function may contribute to the onset of the disease. We review the molecular mechanisms by which these ‘extrinsic’ factors converge on ion channels and provoke their dysregulation to promote the development of PAH. Ion channels of the pulmonary vasculature are therefore promising therapeutic targets because of the modulation they provide to both vasomotor tone and proliferation of arterial smooth muscle cells.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Zhiyu Dai ◽  
Dan Yi ◽  
BIN LIU ◽  
Shuai Li

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: Human genome-wide association studies identified that SOX17 locus variants are associated with PAH. SOX17 mutation is also found in patients with PAH. We hypothesis that endothelial SOX17 deficiency contributes to the pathogenesis of PAH. Methods: Mice with EndoSCL-CreERT mediated deletion of Sox17 ( Sox17 iCKO ) were generated. Sox17 iCKO and Sox17 f/f mice after tamoxifen injection were incubated with hypoxia (10% O 2 ) for 3 weeks to induced PAH. Hemodynamics and histological examination were measured to determine the PAH phenotypes and vascular remodeling. EC proliferation and apoptosis were assessed in SiRNA-mediated SOX17 knockdown in human lung microvascular endothelial cells (hLMVECs). The RNA-sequencing analysis was performed to understand the molecular mechanisms of SOX17 deficiency in ECs. Results: Sox17 iCKO mice exhibited exaggerative PAH evident by the increase of RVSP and RV hypertrophy after hypoxia treatment compared to Sox17 f/f WT mice. SOX17 knockdown in hLMVECs induced cell proliferation and reduced starvation-induced apoptosis. RNA-seq analysis and DAVID pathway analysis demonstrated that there was dysregulation of cell proliferation-related genes, which are enriched in the pathways related to cell cycle, cell division, and mitotic cell cycle. Transcriptional factor, target, and motif discovery analysis of the dysregulated gene set revealed the involvement of transcriptional factors FOXM1 and E2F1. siRNA mediated knockdown of E2F1 but not FOXM1 normalized SOX17 deficiency-induced hLMVECs proliferation and anti-apoptosis. Conclusions: Our study demonstrated that endothelial SOX17 deficiency exaggerates hypoxia-induced PAH. Loss of SOX17 promotes EC proliferation and anti-apoptosis via the upregulation of transcription factor E2F1.


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