The Effects of the Tat86 and Tat101 Isoforms on Oxidative Stress in Human Pulmonary Artery Endothelial Cells: Potential Role in HIV-Associated Pulmonary Arterial Hypertension

2016 ◽  
Vol 100 ◽  
pp. S55
Author(s):  
Jason L Geohring ◽  
Adela Cota-Gomez
2021 ◽  
Vol 11 (1) ◽  
pp. 204589402199619
Author(s):  
Sharon Mumby ◽  
F. Perros ◽  
C. Hui ◽  
B.L. Xu ◽  
W. Xu ◽  
...  

Pulmonary arterial hypertension describes a group of diseases characterised by raised pulmonary vascular resistance, resulting from vascular remodelling in the pre-capillary resistance arterioles. Left untreated, patients die from right heart failure. Pulmonary vascular remodelling involves all cell types but to date the precise roles of the different cells is unknown. This study investigated differences in basal gene expression between pulmonary arterial hypertension and controls using both human pulmonary microvascular endothelial cells and human pulmonary artery smooth muscle cells. Human pulmonary microvascular endothelial cells and human pulmonary artery smooth muscle cells from pulmonary arterial hypertension patients and controls were cultured to confluence, harvested and RNA extracted. Whole genome sequencing was performed and after transcript quantification and normalisation, we examined differentially expressed genes and applied gene set enrichment analysis to the differentially expressed genes to identify putative activated pathways. Human pulmonary microvascular endothelial cells displayed 1008 significant ( p ≤ 0.0001) differentially expressed genes in pulmonary arterial hypertension samples compared to controls. In human pulmonary artery smooth muscle cells, there were 229 significant ( p ≤ 0.0001) differentially expressed genes between pulmonary arterial hypertension and controls. Pathway analysis revealed distinctive differences: human pulmonary microvascular endothelial cells display down-regulation of extracellular matrix organisation, collagen formation and biosynthesis, focal- and cell-adhesion molecules suggesting severe endothelial barrier dysfunction and vascular permeability in pulmonary arterial hypertension pathogenesis. In contrast, pathways in human pulmonary artery smooth muscle cells were mainly up-regulated, including those for fatty acid metabolism, biosynthesis of unsaturated fatty acids, cell–cell and adherens junction interactions suggesting a more energy-driven proliferative phenotype. This suggests that the two cell types play different mechanistic roles in pulmonary arterial hypertension pathogenesis and further studies are required to fully elucidate the role each plays and the interactions between these cell types in vascular remodelling in disease progression.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Oliver ◽  
S.F Rocha ◽  
M Spaczynska ◽  
D.V Lalama ◽  
M Gomez ◽  
...  

Abstract Background Endothelial dysfunction is one of the most important hallmarks of pulmonary arterial hypertension (PAH). This leads to anomalous production of vasoactive mediators that are responsible for a higher vascular tone and a subsequent increase in pulmonary artery pressure (PAP), and to an increased vascular permeability that favors perivascular inflammation and remodeling, thus worsening the disease. Therefore, preservation of the endothelial barrier could become a relevant therapeutic strategy. Purpose In previous studies, others and we have suggested the pharmacological activation of the β3-adrenergic receptor (AR) as a potential therapeutic strategy for pulmonary hypertension (PH) due to left heart disease. However, its potential use in other forms of PH remain unclear. The aim of the present study was to elucidate whether the β3-AR agonist mirabegron could preserve pulmonary endothelium function and be a potential new therapy in PAH. Methods For this purpose, we have evaluated the effect of mirabegron (2 and 10 mg/kg·day) in different animal models, including the monocrotaline and the hypoxia-induced PAH models in rats and mice, respectively. Additionally, we have used a transgenic mouse model with endothelial overexpression of human β3-AR in a knockout background, and performed in vitro experiments with human pulmonary artery endothelial cells (HPAECs) for mechanistic experiments. Results Our results show a dose dependent effect of mirabegron in reducing mean PAP and Right Ventricular Systolic Pressure in both mice and rats. In addition, the use of transgenic mice has allowed us to determine that pulmonary endothelial cells are key mediators of the beneficial role of β3-AR pathway in ameliorating PAH. Mechanistically, we have shown in vitro that activation of β3-AR with mirabegron protects HPAECs from hypoxia-induced ROS production and mitochondrial fragmentation by restoring mitochondrial fission/fusion dynamics. Conclusions This protective effect of mirabegron would lead to endothelium integrity and preserved pulmonary endothelial function, which are necessary for a correct vasodilation, avoiding increased permeability and remodeling. Altogether, the current study demonstrates a beneficial effect of the β3-AR agonist mirabegron that could open new therapeutic avenues in PAH. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Programa de Atracciόn de Talento, Comunidad de Madrid


2016 ◽  
Vol 6 (4) ◽  
pp. 551-556 ◽  
Author(s):  
Raymond L. Benza ◽  
Gretchen Williams ◽  
Changgong Wu ◽  
Kelly J. Shields ◽  
Amresh Raina ◽  
...  

We have previously reported that pulmonary artery endothelial cells (PAECs) can be harvested from the tips of discarded Swan-Ganz catheters after right heart catheterization (RHC). In this study, we tested the hypothesis that the existence of an antiapoptotic phenotype in PAECs obtained during RHC is a distinctive feature of pulmonary arterial hypertension (PAH; World Health Organization group 1) and might be used to differentiate PAH from other etiologies of pulmonary hypertension. Specifically, we developed a flow cytometry-based measure of Bcl-2 activity, referred to as the normalized endothelial Bcl-2 index (NEBI). We report that higher NEBI values are associated with PAH to the exclusion of heart failure with preserved ejection fraction (HFpEF) and that this simple diagnostic measurement is capable of differentiating PAH from HFpEF without presenting addition risk to the patient. If validated in a larger, multicenter study, the NEBI has the potential to assist physicians in the selection of appropriate therapeutic interventions in the common and dangerous scenario wherein patients present a clinical and hemodynamic phenotype that makes it difficult to confidently differentiate between PAH and HFpEF.


Hypertension ◽  
2020 ◽  
Vol 76 (6) ◽  
pp. 1787-1799
Author(s):  
Marina Zemskova ◽  
Nolan McClain ◽  
Maki Niihori ◽  
Mathews V. Varghese ◽  
Joel James ◽  
...  

Damage-associated molecular patterns, such as HMGB1 (high mobility group box 1), play a well-recognized role in the development of pulmonary arterial hypertension (PAH), a progressive fatal disease of the pulmonary vasculature. However, the contribution of the particular type of vascular cells, type of cell death, or the form of released HMGB1 in PAH remains unclear. Moreover, although male patients with PAH show a higher level of circulating HMGB1, its involvement in the severe PAH phenotype reported in males is unknown. In this study, we aimed to investigate the sources and active forms of HMGB1 released from damaged vascular cells and their contribution to the progressive type of PAH in males. Our results showed that HMGB1 is released by either pulmonary artery human endothelial cells or human pulmonary artery smooth muscle cells that underwent necrotic cell death, although only human pulmonary artery smooth muscle cells produce HMGB1 during apoptosis. Moreover, only human pulmonary artery smooth muscle cell death induced a release of dimeric HMGB1, found to be mitochondrial reactive oxygen species dependent, and TLR4 (toll-like receptor 4) activation. The modified Sugen/Hypoxia rat model replicates the human sexual dimorphism in PAH severity (right ventricle systolic pressure in males versus females 54.7±2.3 versus 44.6±2 mm Hg). By using this model, we confirmed that necroptosis and necrosis are the primary sources of circulating HMGB1 in the male rats, although only necrosis increased circulation of HMGB1 dimers. Attenuation of necrosis but not apoptosis or necroptosis prevented TLR4 activation in males and blunted the sex differences in PAH severity. We conclude that necrosis, through the release of HMGB1 dimers, predisposes males to a progressive form of PAH.


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