scholarly journals Endothelial Basement Membrane Components and Their Products, Matrikines: Active Drivers of Pulmonary Hypertension?

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2029
Author(s):  
Ayse Ceren Mutgan ◽  
Katharina Jandl ◽  
Grazyna Kwapiszewska

Pulmonary arterial hypertension (PAH) is a vascular disease that is characterized by elevated pulmonary arterial pressure (PAP) due to progressive vascular remodeling. Extracellular matrix (ECM) deposition in pulmonary arteries (PA) is one of the key features of vascular remodeling. Emerging evidence indicates that the basement membrane (BM), a specialized cluster of ECM proteins underlying the endothelium, may be actively involved in the progression of vascular remodeling. The BM and its steady turnover are pivotal for maintaining appropriate vascular functions. However, the pathologically elevated turnover of BM components leads to an increased release of biologically active short fragments, which are called matrikines. Both BM components and their matrikines can interfere with pivotal biological processes, such as survival, proliferation, adhesion, and migration and thus may actively contribute to endothelial dysfunction. Therefore, in this review, we summarize the emerging role of the BM and its matrikines on the vascular endothelium and further discuss its implications on lung vascular remodeling in pulmonary hypertension.

2012 ◽  
Vol 303 (12) ◽  
pp. C1229-C1243 ◽  
Author(s):  
Abigail S. Forrest ◽  
Talia C. Joyce ◽  
Marissa L. Huebner ◽  
Ramon J. Ayon ◽  
Michael Wiwchar ◽  
...  

Pulmonary artery smooth muscle cells (PASMCs) are more depolarized and display higher Ca2+ levels in pulmonary hypertension (PH). Whether the functional properties and expression of Ca2+-activated Cl− channels (ClCa), an important excitatory mechanism in PASMCs, are altered in PH is unknown. The potential role of ClCa channels in PH was investigated using the monocrotaline (MCT)-induced PH model in the rat. Three weeks postinjection with a single dose of MCT (50 mg/kg ip), the animals developed right ventricular hypertrophy (heart weight measurements) and changes in pulmonary arterial flow (pulse-waved Doppler imaging) that were consistent with increased pulmonary arterial pressure and PH. Whole cell patch experiments revealed an increase in niflumic acid (NFA)-sensitive Ca2+-activated Cl− current [ ICl(Ca)] density in PASMCs from large conduit and small intralobar pulmonary arteries of MCT-treated rats vs. aged-matched saline-injected controls. Quantitative RT-PCR and Western blot analysis revealed that the alterations in ICl(Ca) were accompanied by parallel changes in the expression of TMEM16A, a gene recently shown to encode for ClCa channels. The contraction to serotonin of conduit and intralobar pulmonary arteries from MCT-treated rats exhibited greater sensitivity to nifedipine (1 μM), an l-type Ca2+ channel blocker, and NFA (30 or 100 μM, with or without 10 μM indomethacin to inhibit cyclooxygenases) or T16AInh-A01 (10 μM), TMEM16A/ClCa channel inhibitors, than that of control animals. In conclusion, augmented ClCa/TMEM16A channel activity is a major contributor to the changes in electromechanical coupling of PA in this model of PH. TMEM16A-encoded channels may therefore represent a novel therapeutic target in this disease.


2012 ◽  
Vol 113 (9) ◽  
pp. 1343-1352 ◽  
Author(s):  
Larissa A. Shimoda

When exposed to chronic hypoxia (CH), the pulmonary circulation responds with enhanced contraction and vascular remodeling, resulting in elevated pulmonary arterial pressures. Our work has identified CH-induced alterations in the expression and activity of several ion channels and transporters in pulmonary vascular smooth muscle that contribute to the development of hypoxic pulmonary hypertension and uncovered a critical role for the transcription factor hypoxia-inducible factor-1 (HIF-1) in mediating these responses. Current work is focused on the regulation of HIF in the chronically hypoxic lung and evaluation of the potential for pharmacological inhibitors of HIF to prevent, reverse, or slow the progression of pulmonary hypertension.


1991 ◽  
Vol 71 (6) ◽  
pp. 2218-2223 ◽  
Author(s):  
S. P. Janssens ◽  
B. T. Thompson ◽  
C. R. Spence ◽  
C. A. Hales

Chronic hypoxia increases pulmonary arterial pressure (PAP) as a result of vasoconstriction, polycythemia, and vascular remodeling with medial thickening. To determine whether preventing the polycythemia with repeated bleeding would diminish the pulmonary hypertension and remodeling, we compared hemodynamic and histological profiles in hypoxic bled (HB, n = 6) and hypoxic polycythemic guinea pigs (H, n = 6). After 10 days in hypoxia (10% O2), PAP was increased from 10 +/- 1 (SE) mmHg in room air controls (RA, n = 5) to 20 +/- 1 mmHg in H (P less than 0.05) but was lower in HB (15 +/- 1 mmHg, P less than 0.05 vs. H). Cardiac output and pulmonary artery vasoreactivity did not differ among groups. Total pulmonary vascular resistance increased from 0.072 +/- 0.011 mmHg.ml-1.min in RA to 0.131 mmHg.ml-1.min in H but was significantly lower in HB (0.109 +/- 0.006 mmHg.ml-1.min). Hematocrit increased with hypoxia (57 +/- 3% in H vs. 42 +/- 1% in RA, P less than 0.05), and bleeding prevented the increase (46 +/- 4% in HB, P less than 0.05 vs. H only). The proportion of thick-walled peripheral pulmonary vessels (53.2 +/- 2.9% in HB and 50.6 +/- 4.8% in H vs. 31.6 +/- 2.6% in RA, P less than 0.05) and the percent medial thickness of pulmonary arteries adjacent to alveolar ducts (7.2 +/- 0.6% in HB and 7.0 +/- 0.4% in H vs. 5.2 +/- 0.4% in RA, P less than 0.05) increased to a similar degree in both hypoxic groups. A similar tendency was present in larger bronchiolar vessels.(ABSTRACT TRUNCATED AT 250 WORDS)


Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 57
Author(s):  
Kondababu Kurakula ◽  
Valérie F.E.D. Smolders ◽  
Olga Tura-Ceide ◽  
J. Wouter Jukema ◽  
Paul H. A. Quax ◽  
...  

Pulmonary arterial hypertension (PAH) is a rare, complex, and progressive disease that is characterized by the abnormal remodeling of the pulmonary arteries that leads to right ventricular failure and death. Although our understanding of the causes for abnormal vascular remodeling in PAH is limited, accumulating evidence indicates that endothelial cell (EC) dysfunction is one of the first triggers initiating this process. EC dysfunction leads to the activation of several cellular signalling pathways in the endothelium, resulting in the uncontrolled proliferation of ECs, pulmonary artery smooth muscle cells, and fibroblasts, and eventually leads to vascular remodelling and the occlusion of the pulmonary blood vessels. Other factors that are related to EC dysfunction in PAH are an increase in endothelial to mesenchymal transition, inflammation, apoptosis, and thrombus formation. In this review, we outline the latest advances on the role of EC dysfunction in PAH and other forms of pulmonary hypertension. We also elaborate on the molecular signals that orchestrate EC dysfunction in PAH. Understanding the role and mechanisms of EC dysfunction will unravel the therapeutic potential of targeting this process in PAH.


2015 ◽  
Vol 308 (2) ◽  
pp. L208-L220 ◽  
Author(s):  
Haiyang Tang ◽  
Jiwang Chen ◽  
Dustin R. Fraidenburg ◽  
Shanshan Song ◽  
Justin R. Sysol ◽  
...  

Pulmonary vascular remodeling, mainly attributable to enhanced pulmonary arterial smooth muscle cell proliferation and migration, is a major cause for elevated pulmonary vascular resistance and pulmonary arterial pressure in patients with pulmonary hypertension. The signaling cascade through Akt, comprised of three isoforms (Akt1–3) with distinct but overlapping functions, is involved in regulating cell proliferation and migration. This study aims to investigate whether the Akt/mammalian target of rapamycin (mTOR) pathway, and particularly which Akt isoform, contributes to the development and progression of pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension (HPH). Compared with the wild-type littermates, Akt1 −/− mice were protected against the development and progression of chronic HPH, whereas Akt2 −/− mice did not demonstrate any significant protection against the development of HPH. Furthermore, pulmonary vascular remodeling was significantly attenuated in the Akt1 −/− mice, with no significant effect noted in the Akt2 −/− mice after chronic exposure to normobaric hypoxia (10% O2). Overexpression of the upstream repressor of Akt signaling, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), and conditional and inducible knockout of mTOR in smooth muscle cells were also shown to attenuate the rise in right ventricular systolic pressure and the development of right ventricular hypertrophy. In conclusion, Akt isoforms appear to have a unique function within the pulmonary vasculature, with the Akt1 isoform having a dominant role in pulmonary vascular remodeling associated with HPH. The PTEN/Akt1/mTOR signaling pathway will continue to be a critical area of study in the pathogenesis of pulmonary hypertension, and specific Akt isoforms may help specify therapeutic targets for the treatment of pulmonary hypertension.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
R Ramadhiani ◽  
K Ikeda ◽  
K Miyagawa ◽  
G.R.T Ryanto ◽  
N Tamada ◽  
...  

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


Author(s):  
Qiang Zhao ◽  
Ping Song ◽  
Ming-Hui Zou

Pulmonary hypertension (PH) is a debilitating and life-threatening disease characterized by increased blood pressure within the pulmonary arteries. Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase that contributes to the regulation of metabolic and redox signaling pathways. It has key roles in the regulation of cell survival and proliferation. The role of AMPK in PH is controversial because both inhibition and activation of AMPK are preventive against PH development. Some clinical studies found that metformin, the first-line antidiabetic drug and the canonical AMPK activator, has therapeutic efficacy during treatment of early-stage PH. Other study findings suggest the use of metformin is preferentially beneficial for treatment of PH associated with heart failure with preserved ejection fraction (PH-HFpEF). In this review, we discuss the “AMPK paradox” and highlight the differential effects of AMPK on pulmonary vasoconstriction and pulmonary vascular remodeling. We also review the effects of AMPK activators and inhibitors on rescue of preexisting PH in animals and include a discussion of gender differences in the response to metformin in PH.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Gregoire Ruffenach ◽  
Ellen O'connor ◽  
Mylene Vaillancourt ◽  
JASON HONG ◽  
Victor R Grijalva ◽  
...  

Background: Pulmonary hypertension (PH) is a fatal disease characterized by an increased mean pulmonary arterial pressure above 25mmHg. This increased pressure is, at least in part, due to thickening of the distal pulmonary arteries. Recently, numerous studies demonstrated an increased plasma concentration of oxidized lipids in PH and in diseases where secondary PH developed. Furthermore, 15-hydroxyeicosatetraenoic acid (15-HETE) an oxidized lipid and a major metabolite of arachidonic acid in the lung, has been implicated in dysregulation of major biological pathways in PH. However, the mechanisms involved in the causal role of 15-HETE in pulmonary hypertension development are not known. Methods and Results: To study the role of 15-HETE in PH development, we fed C57BL6/J mice a diet supplemented with 15-HETE for 3 weeks with no other insults. After 3 weeks on the diet with added 15-HETE, C57BL6/J mice had increased concentrations of not only 15-HETE but also of other oxidized lipids (5-, 11- and 12-HETE) in plasma and lung, and they developed PH. RNA-seq analysis revealed the activation of pathways involved in antigen processing and presentation, and with evidence of T cell mediated cytotoxicity in lungs of mice fed 15-HETE. Transcriptomic profiling of lung tissues obtained from patients with pulmonary arterial hypertension (PAH) demonstrated activation of pathways similar to those seen mice. In mice fed a 15-HETE diet, there was an increase in the number of CD8/CD69 double positive cells, as well as an increase in pulmonary arterial endothelial cell (PAEC) apoptosis. Furthermore, PAEC exposed to 15-HETE were more prone to apoptosis when exposed to CD8 cells. Adding Tg6F, an apoA-I mimetic peptide to the 15-HETE diet prevented and rescued PH in C57BL6/J mice, in part, by inhibiting PAEC apoptosis. Conclusions: 15-HETE diet induced PH in C57Bl6/J mice by triggering PAEC death in a T-cell dependent mechanism. The apoA-I mimetic peptide Tg6F was able to prevent and rescue PH induced by 15-HETE.


2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Mehreen Batool ◽  
Eva M. Berghausen ◽  
Mario Zierden ◽  
Marius Vantler ◽  
Ralph T. Schermuly ◽  
...  

AbstractSix-transmembrane protein of prostate (Stamp2) protects from diabetes and atherosclerosis in mice via anti-inflammatory mechanisms. As chronic inflammation is a hallmark of pulmonary arterial hypertension (PAH), we investigated the role of Stamp2. Stamp2 expression was substantially reduced in the lung of humans with idiopathic PAH, as well as in experimental PAH. In Stamp2-deficient mice, hypoxia modestly aggravated pulmonary vascular remodeling and right ventricular pressure compared to WT. As endothelial cell (EC) and pulmonary arterial smooth muscle cell (PASMC) phenotypes drive remodeling in PAH, we explored the role of Stamp2. Knock-down of Stamp2 in human EC neither affected apoptosis, viability, nor release of IL-6. Moreover, Stamp2 deficiency in primary PASMC did not alter mitogenic or migratory properties. As Stamp2 deficiency augmented expression of inflammatory cytokines and numbers of CD68-positive cells in the lung, actions of Stamp2 in macrophages may drive vascular remodeling. Thus, PASMC responses were assessed following treatment with conditioned media of primary Stamp2−/− or WT macrophages. Stamp2−/− supernatants induced PASMC proliferation and migration stronger compared to WT. A cytokine array revealed CXCL12, MCP-1 and IL-6 as most relevant candidates. Experiments with neutralizing antibodies confirmed the role of these cytokines in driving Stamp2’s responses. In conclusion, Stamp2 deficiency aggravates pulmonary vascular remodeling via cross-talk between macrophages and PASMC. Despite a substantial pro-inflammatory response, the hemodynamic effect of Stamp2 deficiency is modest suggesting that additional mechanisms apart from inflammation are necessary to induce severe PAH.


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