scholarly journals DNA methyltransferase 3B deficiency unveils a new pathological mechanism of pulmonary hypertension

2020 ◽  
Vol 6 (50) ◽  
pp. eaba2470
Author(s):  
Yi Yan ◽  
Yang-Yang He ◽  
Xin Jiang ◽  
Yong Wang ◽  
Ji-Wang Chen ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Dna Methyltransferase ◽  
Underlying Mechanism ◽  
Vascular Pathology ◽  
Pulmonary Vascular Remodeling ◽  
Hypoxia Exposure ◽  
Dna Methyltransferase 3B ◽  
Pathological Mechanism

DNA methylation plays critical roles in vascular pathology of pulmonary hypertension (PH). The underlying mechanism, however, remains undetermined. Here, we demonstrate that global DNA methylation was elevated in the lungs of PH rat models after monocrotaline administration or hypobaric hypoxia exposure. We showed that DNA methyltransferase 3B (DNMT3B) was up-regulated in both PH patients and rodent models. Furthermore, Dnmt3b−/− rats exhibited more severe pulmonary vascular remodeling. Consistently, inhibition of DNMT3B promoted proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in response to platelet-derived growth factor–BB (PDGF-BB). In contrast, overexpressing DNMT3B in PASMCs attenuated PDGF-BB–induced proliferation/migration and ameliorated hypoxia-mediated PH and right ventricular hypertrophy in mice. We also showed that DNMT3B transcriptionally regulated inflammatory pathways. Our results reveal that DNMT3B is a previously undefined mediator in the pathogenesis of PH, which couples epigenetic regulations with vascular remodeling and represents a therapeutic target to tackle PH.

scholarly journals Resistin-like Molecule β Acts as a Mitogenic Factor in Hypoxic Pulmonary Hypertension via Ca2+ dependent PI3K/Akt/mTOR and PKC/MAPKs Signaling Pathway

2020 ◽  
Author(s):  
Heshen Tian ◽  
Lei Liu ◽  
Wu Yin ◽  
Ruiwen Wang ◽  
Yongliang Jiang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Signaling Pathway ◽  
Expression Pattern ◽  
Vascular Remodeling ◽  
De Novo ◽  
Underlying Mechanism ◽  
Pulmonary Vascular Remodeling ◽  
Mean Pulmonary Arterial Pressure ◽  
Pulmonary Arterial ◽  
Ventricle Hypertrophy

Abstract BACKGROUND: Pulmonary arterial smooth muscle cells(PASMCs) proliferation plays a crucial role in Hypoxia-induced pulmonary hypertension(HPH). Previous studies have found that Resistin-like molecule β(RELM-β) up-regulated de novo in response to hypoxia in cultured primary human PASMCs(HASMCs). RELM-β has been proved to promote PASMCs proliferation and involved in pulmonary vascular remodeling of patients with PAH. However, the expression pattern, the effects, and the mechanisms of RELM-β in HPH keep unknown. METHODS: We assessed the expression pattern, mitogenetic effect, and underlying mechanism of RELM-β in the rat HPH model and HASMCs. RESULTS: Overexpression of RELM-β alone caused the hemodynamic change in the rat model of HPH, similar to that caused by chronic hypoxia, with increased mean pulmonary arterial pressure(mPAP), right ventricle hypertrophy(RVSP), and thickening of small pulmonary arterioles. Knocking down of RELM-β partially blocked the increased mPAP, RVSP, and vascular remodeling induced by hypoxia. Phosphorylated PI3K/Akt/mTOR and PKC/MAPKs proteins were significantly up- or down-regulated by RELM-β gene overexpression or silencing. Recombinant RELM-β protein increase primary cultured human PASMCs intracellular Ca 2+ concentration and promote HASMCs proliferation. The mitogenic effect of RELM-β on HASMCs and phosphorylated PI3K/Akt/mTOR and PKC/MAPKs was suppressed by Ca 2+ inhibitor. CONCLUSIONS: Our findings suggested that RELM-β acts as a cytokine-like growth factor in the development of HPH and that this process is likely mediated by the Ca 2+ dependent PI3K/Akt/mTOR and PKC/MAPKs pathway. Keywords : hypoxic pulmonary arterial hypertension; resistin-like molecule β; Ca 2+ ; pulmonary vascular remodeling; signaling pathway

Inhibition of Tissue Angiotensin-Converting Enzyme With Quinapril Reduces Hypoxic Pulmonary Hypertension and Pulmonary Vascular Remodeling

Circulation ◽  
1996 ◽  
Vol 94 (8) ◽  
pp. 1941-1947 ◽  
Author(s):  
Zengxuan Nong ◽  
Jean-Marie Stassen ◽  
Lieve Moons ◽  
De´sire´ Collen ◽  
Stefan Janssens
Keyword(s):  
Pulmonary Hypertension ◽  
Angiotensin Converting Enzyme ◽  
Vascular Remodeling ◽  
Converting Enzyme ◽  
Pulmonary Vascular Remodeling ◽  
Hypoxic Pulmonary Hypertension ◽  
Tissue Angiotensin

Metalloproteinase inhibition by Batimastat attenuates pulmonary hypertension in chronically hypoxic rats

2003 ◽  
Vol 285 (1) ◽  
pp. L199-L208 ◽  
Author(s):  
Jan Herget ◽  
Jana Novotná ◽  
Jana Bíbová ◽  
Viera Povýšilová ◽  
Marie Vaňková ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Chronic Hypoxia ◽  
Causative Factor ◽  
Systemic Arterial Pressure ◽  
Collagenolytic Activity ◽  
Pulmonary Vascular Remodeling ◽  
Arterial Blood ◽  
Fraction Of Inspired Oxygen ◽  
Lung Vessels

Chronic hypoxia induces lung vascular remodeling, which results in pulmonary hypertension. We hypothesized that a previously found increase in collagenolytic activity of matrix metalloproteinases during hypoxia promotes pulmonary vascular remodeling and hypertension. To test this hypothesis, we exposed rats to hypoxia (fraction of inspired oxygen = 0.1, 3 wk) and treated them with a metalloproteinase inhibitor, Batimastat (30 mg/kg body wt, daily ip injection). Hypoxia-induced increases in concentration of collagen breakdown products and in collagenolytic activity in pulmonary vessels were inhibited by Batimastat, attesting to the effectiveness of Batimastat administration. Batimastat markedly reduced hypoxic pulmonary hypertension: pulmonary arterial blood pressure was 32 ± 3 mmHg in hypoxic controls, 24 ± 1 mmHg in Batimastat-treated hypoxic rats, and 16 ± 1 mmHg in normoxic controls. Right ventricular hypertrophy and muscularization of peripheral lung vessels were also diminished. Batimastat had no influence on systemic arterial pressure or cardiac output and was without any effect in rats kept in normoxia. We conclude that stimulation of collagenolytic activity in chronic hypoxia is a substantial causative factor in the pathogenesis of pulmonary vascular remodeling and hypertension.

scholarly journals The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes

2015 ◽  
Vol 308 (3) ◽  
pp. L229-L252 ◽  
Author(s):  
Steven C. Pugliese ◽  
Jens M. Poth ◽  
Mehdi A. Fini ◽  
Andrea Olschewski ◽  
Karim C. El Kasmi ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Signaling Pathways ◽  
Vascular Remodeling ◽  
Mesenchymal Cells ◽  
World Health ◽  
Small Subset ◽  
Cellular Interactions ◽  
Pulmonary Vascular Remodeling ◽  
Hypoxic Pulmonary Hypertension ◽  
Group I

Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop “out-of-proportion” severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines (“second hit”) antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.

scholarly journals HIF2α–arginase axis is essential for the development of pulmonary hypertension

2016 ◽  
Vol 113 (31) ◽  
pp. 8801-8806 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Alexi Crosby ◽  
David Macias ◽  
Cristina Branco ◽  
Renato D. D. R. Colaço ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Systolic Pressure ◽  
Hypoxic Exposure ◽  
Pulmonary Vascular Remodeling ◽  
Ventricular Systolic Pressure ◽  
Pulmonary Endothelium ◽  
Arginase 1

Hypoxic pulmonary vasoconstriction is correlated with pulmonary vascular remodeling. The hypoxia-inducible transcription factors (HIFs) HIF-1α and HIF-2α are known to contribute to the process of hypoxic pulmonary vascular remodeling; however, the specific role of pulmonary endothelial HIF expression in this process, and in the physiological process of vasoconstriction in response to hypoxia, remains unclear. Here we show that pulmonary endothelial HIF-2α is a critical regulator of hypoxia-induced pulmonary arterial hypertension. The rise in right ventricular systolic pressure (RVSP) normally observed following chronic hypoxic exposure was absent in mice with pulmonary endothelial HIF-2α deletion. The RVSP of mice lacking HIF-2α in pulmonary endothelium after exposure to hypoxia was not significantly different from normoxic WT mice and much lower than the RVSP values seen in WT littermate controls and mice with pulmonary endothelial deletion of HIF-1α exposed to hypoxia. Endothelial HIF-2α deletion also protected mice from hypoxia remodeling. Pulmonary endothelial deletion of arginase-1, a downstream target of HIF-2α, likewise attenuated many of the pathophysiological symptoms associated with hypoxic pulmonary hypertension. We propose a mechanism whereby chronic hypoxia enhances HIF-2α stability, which causes increased arginase expression and dysregulates normal vascular NO homeostasis. These data offer new insight into the role of pulmonary endothelial HIF-2α in regulating the pulmonary vascular response to hypoxia.

Hypoxia-Induced Changes in the Mechanical Properties of the Mouse Pulmonary Artery

2003 ◽  
Author(s):  
Ryan W. Kobs ◽  
Nidal E. Muvarak ◽  
Naomi C. Chesler
Keyword(s):  
Mechanical Properties ◽  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Hypobaric Hypoxia ◽  
Vessel Wall ◽  
Main Pulmonary Artery ◽  
Collagen Content ◽  
Pulmonary Vascular Remodeling ◽  
Induced Changes

Hypobaric hypoxia produces pulmonary hypertension in mice which causes pulmonary vascular remodeling. To study the biomechanics of this process, mice were exposed to hypoxia for 0-(control), 10-, and 15-days. Using a pressurized arteriograph system, mechanical properties of the main pulmonary artery were measured and compared to the biological changes in the vessel wall measured histologically. 10- and 15-day hypoxic vessels were significantly stiffer when compared to 0-day vessels. This stiffness correlated with greater elastin and collagen content in the vessel wall.

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