Abstract 263: Differential Effects of 17ß-Estradiol and 16a-Hydroxyestrone in Oxidative Stress and Proliferative Responses in Human Pulmonary Artery Smooth Muscle Cells - Implications in Pulmonary Arterial Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Katie Y Hood ◽  
Augusto C Montezano ◽  
Margaret R MacLean ◽  
Rhian M Touyz
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Arterial Hypertension ◽  
Cell Growth ◽  
Arterial Hypertension ◽  
Molecular Mechanisms ◽  
Antioxidant Systems ◽  
Ros Generation ◽  
Ros Production ◽  
Differential Effects ◽  
Pulmonary Arterial

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.

scholarly journals Effects of ovariectomy on antioxidant defence systems in the right ventricle of female rats with pulmonary arterial hypertension induced by monocrotaline

2018 ◽  
Vol 96 (3) ◽  
pp. 295-303 ◽  
Author(s):  
Rafaela Siqueira ◽  
Rafael Colombo ◽  
Adriana Conzatti ◽  
Alexandre Luz de Castro ◽  
Cristina Campos Carraro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Arterial Hypertension ◽  
Right Ventricle ◽  
Protein Expression ◽  
Arterial Hypertension ◽  
Female Rats ◽  
Antioxidant Defenses ◽  
Thioredoxin 1 ◽  
Pulmonary Arterial ◽  
The Right

The aim of this study was to evaluate the impact of ovariectomy on oxidative stress in the right ventricle (RV) of female rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). Rats were divided into 4 groups (n = 6 per group): sham (S), sham + MCT (SM), ovariectomized (O), and ovariectomized + MCT (OM). MCT (60 mg·kg−1 i.p.) was injected 1 week after ovariectomy or sham surgery. Three weeks later, echocardiographic analysis and RV catheterisation were performed. RV morphometric, biochemical, and protein expression analysis through Western blotting were done. MCT promoted a slight increase in pulmonary artery pressure, without differences between the SM and OM groups, but did not induce RV hypertrophy. RV hydrogen peroxide increased in the MCT groups, but SOD, CAT, and GPx activities were also enhanced. Non-classical antioxidant defenses diminished in ovariectomized groups, probably due to a decrease in the nuclear factor Nrf2. Hemoxygenase-1 and thioredoxin-1 protein expression was increased in the OM group compared with SM, being accompanied by an elevation in the estrogen receptor β (ER-β). Hemoxygenase-1 and thioredoxin-1 may be involved in the modulation of oxidative stress in the OM group, and this could be responsible for attenuation of PAH and RV remodeling.

scholarly journals Elucidation of the mechanisms and molecular targets of Qishen Yiqi formula for the treatment of pulmonary arterial hypertension using a bioinformatics/network topology-based strategy

2020 ◽  
Vol 23 ◽  
Author(s):  
Peiliang Wu ◽  
Xiaona Xie ◽  
Mayun Chen ◽  
Junwei Sun ◽  
Luqiong Cai ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Network Topology ◽  
Molecular Mechanisms ◽  
Molecular Targets ◽  
Enrichment Analysis ◽  
Network Pharmacology ◽  
Pathway Enrichment Analysis ◽  
Bioactive Ingredients ◽  
Pulmonary Arterial

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.

Abstract 382: Cyclophilin A (CypA) is a Pathogenic Mediator of Pulmonary Arterial Hypertension

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Chao Xue
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Specific Inhibitor ◽  
Cyclophilin A ◽  
Pulmonary Vasculature ◽  
Tunel Staining ◽  
Mesenchymal Transition ◽  
Pulmonary Arterial

Rationale: Pulmonary arterial hypertension (PAH) is a devastating disease in which oxidative stress has been proposed to mediate pathological changes to the pulmonary vasculature such as endothelial cell (EC) apoptosis, endothelial to mesenchymal transition (EndMT), vascular smooth muscle cell (VSMC) proliferation, and inflammation. Our previous study showed that cyclophilin A (CypA) was secreted from EC and VSMC in response to oxidative stress, and much of the secreted CypA was acetylated (AcK-CypA). Furthermore, CypA was increased in the plasma of patients with PAH. Objective: To evaluate the cell- s pecific role of CypA in PAH and compare the relative effects of AcK-CypA and CypA on EC apoptosis, development of an inflammatory EC phenotype and EndMT. Methods and Results: Transgenic overexpression of CypA in EC, but not SMC, caused a PAH phenotype including increased pulmonary artery pressure, α-smooth muscle actin expression in small arteries, and CD45 positive cells in the lungs. Mechanistic analysis using cultured mouse lung microvascular EC showed that CypA and AcK-CypA increased apoptosis measured by caspase 3 cleavage and TUNEL staining. MM284, a specific inhibitor of extracellular CypA, prevented EC apoptosis. In addition, CypA and AcK-CypA promoted an EC inflammatory phenotype assessed by increased VCAM1 and ICAM1 expression, phosphorylation of p65, and degradation of IkB. Furthermore, CypA and AcK-CypA promoted EndMT assayed by change in cell morphology, increased mesenchymal markers and EndMT related transcription factors. At all concentrations, AcK-CypA stimulated greater increases in apoptosis, inflammation and EndMT than CypA. Conclusions: EC-derived CypA (especially AcK-CypA) causes PAH by a presumptive mechanism involving increased EC apoptosis, inflammation and EndMT. Our results suggest that inhibiting extracellular secreted CypA is a novel therapeutic approach for PAH.

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 Pathophysiology, incidence, management, and consequences of cardiac arrhythmia in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

2019 ◽  
Vol 9 (1) ◽  
pp. 204589401983489 ◽  
Author(s):  
Meghan M. Cirulis ◽  
John J. Ryan ◽  
Stephen L. Archer
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Molecular Mechanisms ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Outcome Data ◽  
Current Evidence ◽  
Clinical Aspects ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Arterial

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.

scholarly journals Obesity alters oestrogen metabolism and contributes to pulmonary arterial hypertension

2019 ◽  
Vol 53 (6) ◽  
pp. 1801524 ◽  
Author(s):  
Kirsty M. Mair ◽  
Katie Y. Harvey ◽  
Alasdair D. Henry ◽  
Dianne Z. Hillyard ◽  
Margaret Nilsen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Cytochrome P450 1B1 ◽  
Stress Effects ◽  
Endogenous Oestrogen ◽  
Pulmonary Arterial ◽  
Induced Changes ◽  
Species Production

Obesity is a common comorbidity for pulmonary arterial hypertension (PAH). Additionally, oestrogen and its metabolites are risk factors for the development of PAH. Visceral adipose tissue (VAT) is a major site of oestrogen production; however, the influence of obesity-induced changes in oestrogen synthesis and metabolism on the development of PAH is unclear. To address this we investigated the effects of inhibiting oestrogen synthesis and metabolism on the development of pulmonary hypertension in male and female obese mice.We depleted endogenous oestrogen in leptin-deficient (ob/ob) mice with the oestrogen inhibitor anastrozole (ANA) and determined the effects on the development of pulmonary hypertension, plasma oestradiol and urinary 16α-hydroxyestrone (16αOHE1). Oestrogen metabolism through cytochrome P450 1B1 (CYP1B1) was inhibited with 2,2′,4,6′-tetramethoxystilbene (TMS).ob/ob mice spontaneously develop pulmonary hypertension, pulmonary vascular remodelling and increased reactive oxygen species production in the lung; these effects were attenuated by ANA. Oestradiol levels were decreased in obese male mice; however, VAT CYP1B1 and 16αOHE1 levels were increased. TMS also attenuated pulmonary hypertension in male ob/ob mice. Intra-thoracic fat from ob/ob mice and VAT conditioned media produce 16αOHE1 and can contribute to oxidative stress, effects that are attenuated by both ANA and TMS.Obesity can induce pulmonary hypertension and changes in oestrogen metabolism, resulting in increased production of 16αOHE1 from VAT that contributes to oxidative stress. Oestrogen inhibitors are now in clinical trials for PAH. This study has translational consequences as it suggests that oestrogen inhibitors may be especially beneficial in treating obese individuals with PAH.

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