Sex Differences in Right Ventricular-Vascular Coupling and Pulmonary Artery Impedance in Response to Chronic Hypoxia and Recovery

2012 ◽  
Author(s):  
Aiping Liu ◽  
Lian Tian ◽  
Diana M. Tabima ◽  
Naomi C. Chesler
Keyword(s):  
Pulmonary Artery ◽  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Pulmonary Artery Hypertension ◽  
Vascular Impedance ◽  
Female Predominance ◽  
Collagen Accumulation ◽  
Dominant Disease ◽  
Pulmonary Arterial

Pulmonary artery hypertension (PAH) is a female dominant disease (the female-to-male ratio is 4:1), characterized by small distal pulmonary arterial narrowing and large proximal arterial stiffening, which increase right ventricle (RV) afterload and ultimately lead to RV failure [1,2]. Our recent studies have shown that collagen accumulation induced by chronic hypoxia increases the stiffness of the large extralobar pulmonary arteries (PAs) [3], and affects pulmonary vascular impedance (PVZ) [4]. The role of collagen in the female predominance in developing PAH has not been explored to date.

Effects of Estrogen on Pulmonary Vascular Remodeling in Pulmonary Artery Hypertension

2013 ◽  
Author(s):  
Aiping Liu ◽  
Naomi Chesler
Keyword(s):  
Pulmonary Artery ◽  
Progressive Increase ◽  
Pulmonary Artery Hypertension ◽  
Pulmonary Vascular Remodeling ◽  
Vegf Inhibitor ◽  
Vascular Impedance ◽  
Pulmonary Arterial ◽  
The Relationship

Pulmonary artery hypertension (PAH) is a female dominant, fatal disease characterized by progressive increase of pulmonary vascular resistance and loss of compliance. The role of estrogen in these pulmonary vascular changes with PAH progression remains unclear. Our objective was to study the effects of estrogen on pulmonary arterial (PA) remodeling in a mouse model of progressive PAH, created via a combination of a VEGF inhibitor Sugen and chronic hypoxia (SuHx). To quantify PA hemodynamics, we measured in vivo pressure and flow simultaneously in live mice in order to obtain pulmonary vascular impedance, a comprehensive measure of RV afterload. Our results demonstrate that estrogen modifies the relationship between PA resistance and compliance by attenuating PA stiffening, which provides insight into sex differences in PAH progression.

scholarly journals Pathobiology of pulmonary artery hypertension: role of long non-coding RNAs

2020 ◽  
Vol 116 (12) ◽  
pp. 1937-1947 ◽  
Author(s):  
Kashif Rafiq Zahid ◽  
Umar Raza ◽  
Jidong Chen ◽  
Usha J Raj ◽  
Deming Gou
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular Dysfunction ◽  
Pulmonary Artery Hypertension ◽  
Endothelial Cell Proliferation ◽  
Vascular Remodelling ◽  
Mesenchymal Transition ◽  
Pulmonary Arterial ◽  
Non Coding Rnas

Abstract Pulmonary arterial hypertension (PAH) is a disease with complex pathobiology, significant morbidity and mortality, and remains without a cure. It is characterized by vascular remodelling associated with uncontrolled proliferation of pulmonary artery smooth muscle cells, endothelial cell proliferation and dysfunction, and endothelial-to-mesenchymal transition, leading to narrowing of the vascular lumen, increased vascular resistance and pulmonary arterial pressure, which inevitably results in right heart failure and death. There are multiple molecules and signalling pathways that are involved in the vascular remodelling, including non-coding RNAs, i.e. microRNAs and long non-coding RNAs (lncRNAs). It is only in recent years that the role of lncRNAs in the pathobiology of pulmonary vascular remodelling and right ventricular dysfunction is being vigorously investigated. In this review, we have summarized the current state of knowledge about the role of lncRNAs as key drivers and gatekeepers in regulating major cellular and molecular trafficking involved in the pathogenesis of PAH. In addition, we have discussed the limitations and challenges in translating lncRNA research in vivo and in therapeutic applications of lncRNAs in PAH.

scholarly journals Membrane depolarization is required for pressure-dependent pulmonary arterial tone but not enhanced vasoconstriction to endothelin-1 following chronic hypoxia

2020 ◽  
Vol 10 (4) ◽  
pp. 204589402097355
Author(s):  
Charles E Norton ◽  
Nikki L Jernigan ◽  
Benjimen R Walker ◽  
Thomas C Resta
Keyword(s):  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Rho Kinase ◽  
Membrane Depolarization ◽  
Src Kinases ◽  
Endothelin 1 ◽  
Receptor Inhibition ◽  
Pulmonary Arterial ◽  
Arterial Tone

Enhanced vasoconstriction is increasingly identified as an important contributor to the development of pulmonary hypertension. Chronic hypoxia results in enhanced Rho kinase mediated Ca2+ sensitization contributing to pressure-dependent pulmonary arterial tone as well as augmented vasoconstriction to endothelin-1 and depolarizing stimuli. We sought to investigate the interaction between these vasoconstrictor stimuli in isolated, pressurized, pulmonary arteries. We used the K+ ionophore, valinomycin, to clamp membrane potential (Vm) to investigate the role of membrane depolarization in endothelin-1 and pressure-dependent constriction, and endothelin-1 receptor inhibitors to determine whether membrane depolarization or stretch signal through endothelin-1 receptors. Clamping Vm prevented pressure-dependent tone, but not enhanced vasoconstriction to endothelin-1 following chronic hypoxia. Furthermore, endothelin-1 receptor inhibition had no effect on either pressure-dependent tone or vasoconstriction to KCl. As Src kinases contribute to both pressure-dependent tone and enhanced endothelin-1 vasoconstriction following chronic hypoxia, we further investigated their role in depolarization-induced vasoconstriction. Inhibition of Src kinases attenuated enhanced vasoconstriction to KCl. We conclude that membrane depolarization contributes to pressure-dependent tone but not enhanced vasoconstriction to ET-1, and that Src kinases serve as upstream mediators facilitating enhanced Rho kinase-dependent vasoconstriction following chronic hypoxia.

Chronic hypoxia inhibits Kv channel gene expression in rat distal pulmonary artery

2005 ◽  
Vol 288 (6) ◽  
pp. L1049-L1058 ◽  
Author(s):  
Jian Wang ◽  
Letitia Weigand ◽  
Wenqian Wang ◽  
J. T. Sylvester ◽  
Larissa A. Shimoda
Keyword(s):  
Gene Expression ◽  
Pulmonary Artery ◽  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Mrna Levels ◽  
Protein Levels ◽  
Kv Channel ◽  
Channel Gene ◽  
Pulmonary Arterial ◽  
Α Subunits

In pulmonary arterial smooth muscle cells (PASMCs), voltage-gated K+ (Kv) channels play an important role in regulating membrane potential, cytoplasmic free Ca2+ concentration, and pulmonary vasomotor tone. Previous studies demonstrated that exposure of rats to chronic hypoxia decreased Kv channel function in PASMCs from distal pulmonary arteries (dPA). To determine whether this decrease in function was due to decreased expression of Kv channel proteins and which Kv proteins might be involved, we analyzed Kv channel gene expression in intact, endothelium-denuded dPAs obtained from rats exposed to 10% O2 for 3 wk. Kv1.1, Kv1.2, Kv1.4, Kv1.5, Kv1.6, Kv2.1, Kv3.1, Kv4.3, and Kv9.3 channel α-subunits and Kv1, Kv2, and Kv3 β-subunits were expressed in rat dPAs. Exposure to chronic hypoxia decreased mRNA and protein levels of Kv1.1, Kv1.5, Kv1.6, Kv2.1, and Kv4.3 α-subunits in dPAs but did not alter gene or protein expression of these channels in aorta. Furthermore, chronic hypoxia did not alter the mRNA levels of β-subunits in dPAs. These results suggest that diminished transcription of Kv α-subunits may reduce the number of functional Kv channels in dPAs during prolonged hypoxia, causing the decreased Kv current previously observed in PASMCs and leading to pulmonary artery vasoconstriction.

Endothelial cell premature senescence exacerbates pulmonary arterial hypertension through contact-mediated interaction with vascular smooth muscle cells

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
R Ramadhiani ◽  
K Ikeda ◽  
K Miyagawa ◽  
G.R.T Ryanto ◽  
N Tamada ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Endothelial Cell ◽  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Pulmonary Arteries ◽  
Premature Senescence ◽  
Pulmonary Arterial ◽  
Human Pulmonary Artery

Abstract Introduction Pulmonary arterial hypertension (PAH) is characterized by remodelling and stenosis of the pulmonary arteries, ultimately leading to the right heart failure and death. Endothelial cell (EC) dysfunction is thought to play a central role in the pathogenesis of PAH by mediating the structural changes in pulmonary vasculatures. Various stresses promote premature senescence in EC, which may modify vascular disorders; however, the role of EC senescence in the development of PAH remains poorly understood. Purpose We aimed at investigating the potential role of EC premature senescence in the development of PAH. Methods We recently generated EC-specific progeroid mice in which ECs specifically undergo premature senescence by overexpressing the dominant-negative form of telomere repeat-binding factor 2 (published in Nat Commun 2020). These EC-specific progeroid mice were exposed to hypoxia (10% O2 for three weeks) to induce pulmonary hypertension. Also, we prepared premature senescent ECs using human pulmonary artery ECs (hPAECs) and explored their interaction with human pulmonary artery smooth muscle cells (hPASMCs) in two different conditions; direct and indirect interactions. For indirect coculture, hPASMCs were seeded onto the culture insert, while hPAECs were plated on the culture plate, and they were cocultured in the same well and medium so that secreted factors derived from senescent ECs could access to SMCs through the insert pores. For direct coculture, hPAECs were seeded onto the bottom side of the insert, while hPASMCs were cultured on the top side of the same insert, so that cell-to-cell contact could be made through the pores. Results After chronic hypoxia exposure, the EC-specific progeroid mice showed higher right ventricular systolic pressure and increased right ventricular mass as compared to wild-type (WT) mice, indicating exacerbated pulmonary hypertension. Histological analysis of the lung revealed a significantly enhanced muscularization in the small pulmonary arteries in EC-specific progeroid mice compared to WT mice. Mechanistically, we identified that direct coculture with premature senescent hPAECs enhanced proliferation and migration in hPASMCs, while no such effects were detected in indirect coculture condition. Conclusion To our knowledge, this is the first report that reveals a crucial role of EC premature senescence in the development of PAH. Our in vitro studies suggest that contact-mediated interaction between premature senescent ECs and SMCs is critically involved in its underlying mechanism. Therefore, EC premature senescence is a novel attractive pharmacotherapeutic target for the treatment of PAH. Funding Acknowledgement Type of funding source: None

Involvement of nitric oxide and nitrosothiols in relaxation of pulmonary arteries to peroxynitrite

1994 ◽  
Vol 266 (5) ◽  
pp. H2108-H2113 ◽  
Author(s):  
M. Wu ◽  
K. A. Pritchard ◽  
P. M. Kaminski ◽  
R. P. Fayngersh ◽  
T. H. Hintze ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Artery ◽  
Vascular Tissue ◽  
Soluble Guanylate Cyclase ◽  
Pulmonary Arteries ◽  
Arterial Tissue ◽  
Pulmonary Arterial ◽  
Pulmonary Arterial Smooth Muscle ◽  
Ly 83583

Peroxynitrite (ONOO-) is an inflammatory cell-derived oxidant, formed by the reaction of superoxide anion (O2-) with nitric oxide (NO), which was recently reported to relax vascular tissues. In the present study, the potential role of NO in the mechanism of relaxation in isolated bovine endothelium-denuded pulmonary arterial smooth muscle rings to ONOO- was evaluated. Potassium-preconstricted pulmonary arterial rings rapidly relaxed for a prolonged period of time on exposure to ONOO- (0.01-0.1 mM). The relaxation after 1 min of exposure to ONOO- (0.1 mM) was reduced 49 and 87%, respectively, by inhibitors of the stimulation of soluble guanylate cyclase, methylene blue, and LY-83583. In contrast, a scavenger of hydroxyl radicals, dimethyl sulfoxide, did not alter this response. Decomposed 0.1 mM ONOO- (which is primarily nitrite) and 0.1 mM nitrite caused a relaxation of pulmonary artery, which slowly developed over 15 min. Small quantities of NO were detected by chemiluminescence quantification methods when ONOO- was added to buffer. Exposure of pulmonary arterial tissue or buffer containing glutathione (GSH) to ONOO- caused a time-dependent increase in the observed generation of NO, whereas decomposed ONOO- produced 10% of the NO generated by ONOO- on incubation with pulmonary arterial tissue. Treatment with diethyl maleate, an agent that depletes tissue GSH, reduced both the relaxation and the formation of NO detected from pulmonary artery on exposure to ONOO-. GSH solutions treated with ONOO- appear to have generated a nitrosothiol-like vascular relaxant compound. Thus ONOO- appears to relax vascular tissue, in part, by nitrosylating tissue GSH (or other thiols), which subsequently releases NO over prolonged time periods.

scholarly journals Emerging Role of Galectin-3 in Pulmonary Artery Hypertension

2018 ◽  
Vol 1 (1) ◽  
pp. p35
Author(s):  
Alexander E. Berezin
Keyword(s):  
Heart Failure ◽  
Cell Proliferation ◽  
Pulmonary Artery ◽  
Short Communication ◽  
Clinical Status ◽  
Pulmonary Artery Hypertension ◽  
All Cause Mortality ◽  
Galectin 3 ◽  
Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is multifactorial disadptive disease with poor clinical outcomes associated with increased pulmonary artery pressure resulting in primary small-to-moderate pulmonary artery remodeling. Numerous factors, including smooth muscle cell proliferation, vasospasm, vascular fibrosis and occlusion, direct vascular injury and inflammation, impaired repair of vasculature, are involved in the pathogenesis of PAH. It has been suggested that galectin-3 as a biomarker of excessive fibrosis and inflammation can be useful predictor of both severity and prognosis in patient with PAH. The short communication is reported that elevated Gal-3 levels were found in majority patients with PAH depending on clinical status and of the disease. Although elevated Gal-3 levels were associated with a higher risk of all-cause mortality, cardiovascular mortality, and right ventricle heart failure, the value of this biomarker in PAH patients at high risk stratification is uncertain and requires to be investigated in large clinical trials.

scholarly journals The Role of Collagen Synthesis in Ventricular and Vascular Adaptation to Hypoxic Pulmonary Hypertension

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
David Schreier ◽  
Timothy Hacker ◽  
Gouqing Song ◽  
Naomi Chesler
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Collagen Synthesis ◽  
Chronic Hypoxia ◽  
Coupling Efficiency ◽  
Pulmonary Arteries ◽  
Collagen Accumulation ◽  
The Impact ◽  
Rv Function

Pulmonary arterial hypertension (PAH) is a rapidly fatal disease in which mortality is typically due to right ventricular (RV) failure. An excellent predictor of mortality in PAH is proximal pulmonary artery stiffening, which is mediated by collagen accumulation in hypoxia-induced pulmonary hypertension (HPH) in mice. We sought to investigate the impact of limiting vascular and ventricular collagen accumulation on RV function and the hemodynamic coupling efficiency between the RV and pulmonary vasculature. Inbred mice were exposed to chronic hypoxia for 10 days with either no treatment (HPH) or with treatment with a proline analog that impairs collagen synthesis (CHOP-PEG; HPH + CP). Both groups were compared to control mice (CTL) exposed only to normoxia (no treatment). An admittance catheter was used to measure pressure-volume loops at baseline and during vena cava occlusion, with mice ventilated with either room air or 8% oxygen, from which pulmonary hemodynamics, RV function, and ventricular-vascular coupling efficiency (ηvvc) were calculated. Proline analog treatment limited increases in RV afterload (neither effective arterial elastance Ea nor total pulmonary vascular resistance significantly increased compared to CTL with CHOP-PEG), limited the development of pulmonary hypertension (CHOP-PEG reduced right ventricular systolic pressure by 10% compared to HPH, p < 0.05), and limited RV hypertrophy (CHOP-PEG reduced RV mass by 18% compared to HPH, p < 0.005). In an acutely hypoxic state, treatment improved RV function (CHOP-PEG increased end-systolic elastance Ees by 43%, p < 0.05) and maintained ηvvc at control, room air levels. CHOP-PEG also decreased lung collagen content by 12% measured biochemically compared to HPH (p < 0.01), with differences evident in large and small pulmonary arteries by histology. Our results demonstrate that preventing new collagen synthesis limits pulmonary hypertension development by reducing collagen accumulation in the pulmonary arteries that affect RV afterload. In particular, the proline analog limited structural and functional changes in distal pulmonary arteries in this model of early and somewhat mild pulmonary hypertension. We conclude that collagen plays an important role in small pulmonary artery remodeling and, thereby, affects RV structure and function changes induced by chronic hypoxia.

scholarly journals Reduced membrane cholesterol limits pulmonary endothelial Ca2+ entry after chronic hypoxia

2017 ◽  
Vol 312 (6) ◽  
pp. H1176-H1184 ◽  
Author(s):  
Bojun Zhang ◽  
Jay S. Naik ◽  
Nikki L. Jernigan ◽  
Benjimen R. Walker ◽  
Thomas C. Resta
Keyword(s):  
Pulmonary Hypertension ◽  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Barometric Pressure ◽  
Membrane Cholesterol ◽  
Potential Mechanism ◽  
Direct Role ◽  
Pulmonary Arterial ◽  
Arterial Endothelial Cells

Chronic hypoxia (CH)-induced pulmonary hypertension is associated with diminished production of endothelium-derived Ca2+-dependent vasodilators such as nitric oxide. Interestingly, ATP-induced endothelial Ca2+ entry as well as membrane cholesterol (Chol) are decreased in pulmonary arteries from CH rats (4 wk, barometric pressure = 380 Torr) compared with normoxic controls. Store-operated Ca2+ entry (SOCE) and depolarization-induced Ca2+ entry are major components of the response to ATP and are similarly decreased after CH. We hypothesized that membrane Chol facilitates both SOCE and depolarization-induced pulmonary endothelial Ca2+ entry and that CH attenuates these responses by decreasing membrane Chol. To test these hypotheses, we administered Chol or epicholesterol (Epichol) to acutely isolated pulmonary arterial endothelial cells (PAECs) from control and CH rats to either supplement or replace native Chol, respectively. The efficacy of membrane Chol manipulation was confirmed by filipin staining. Epichol greatly reduced ATP-induced Ca2+ influx in PAECs from control rats. Whereas Epichol similarly blunted endothelial SOCE in PAECs from both groups, Chol supplementation restored diminished SOCE in PAECs from CH rats while having no effect in controls. Similar effects of Chol manipulation on PAEC Ca2+ influx were observed in response to a depolarizing stimulus of KCl. Furthermore, KCl-induced Ca2+ entry was inhibited by the T-type Ca2+ channel antagonist mibefradil but not the L-type Ca2+ channel inhibitor diltiazem. We conclude that PAEC membrane Chol is required for ATP-induced Ca2+ entry and its two components, SOCE and depolarization-induced Ca2+ entry, and that reduced Ca2+ entry after CH may be due to loss of this key regulator. NEW & NOTEWORTHY This research is the first to examine the direct role of membrane cholesterol in regulating pulmonary endothelial agonist-induced Ca2+ entry and its components. The results provide a potential mechanism by which chronic hypoxia impairs pulmonary endothelial Ca2+ influx, which may contribute to pulmonary hypertension.

scholarly journals Chronic hypoxia upregulates pulmonary arterial ASIC1: a novel mechanism of enhanced store-operated Ca2+ entry and receptor-dependent vasoconstriction

2012 ◽  
Vol 302 (6) ◽  
pp. C931-C940 ◽  
Author(s):  
Nikki L. Jernigan ◽  
Lindsay M. Herbert ◽  
Benjimen R. Walker ◽  
Thomas C. Resta
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Ion Channel ◽  
Vessel Wall ◽  
Wistar Rats ◽  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Intracellular Ca ◽  
Pulmonary Arterial

Acid-sensing ion channel 1 (ASIC1) is a newly characterized contributor to store-operated Ca2+ entry (SOCE) in pulmonary vascular smooth muscle (VSM). Since SOCE is implicated in elevated basal VSM intracellular Ca2+ concentration ([Ca2+]i) and augmented vasoconstriction in chronic hypoxia (CH)-induced pulmonary hypertension, we hypothesized that ASIC1 contributes to these responses. To test this hypothesis, we examined effects of the specific pharmacologic ASIC1a inhibitor, psalmotoxin 1 (PcTX1), on vasoconstrictor and vessel wall [Ca2+]i responses to UTP and KCl (depolarizing stimulus) in fura-2-loaded, pressurized small pulmonary arteries from control and CH (4 wk at 0.5 atm) Wistar rats. PcTX1 had no effect on basal vessel wall [Ca2+]i, but attenuated vasoconstriction and increases in vessel wall [Ca2+]i to UTP in arteries from control and CH rats; normalizing responses between groups. In contrast, responses to the depolarizing stimulus, KCl, were unaffected by CH exposure or PcTX1. Upon examining potential Ca2+ influx mechanisms, we found that PcTX1 prevented augmented SOCE following CH. Exposure to CH resulted in a significant increase in pulmonary arterial ASIC1 protein. This study supports a novel role of ASIC1 in elevated receptor-stimulated vasoconstriction following CH which is likely mediated through increased ASIC1 expression and SOCE.

Sign in / Sign up

Export Citation Format

Share Document