P6008Inhibin Beta-A is a novel gene involved in the development of pulmonary arterial hypertension through inhibiting BMPRII-signaling in endothelial cells

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
G R T Ryanto ◽  
K Ikeda ◽  
K Miyagawa ◽  
K Yagi ◽  
Y Suzuki ◽  
...  

Abstract Introduction Pulmonary Arterial Hypertension (PAH) is marked by vascular remodeling process that eventually causes pressure increase. Endothelial cells (EC) dysfunction is known to be a major cause for pulmonary vascular remodeling; however, the molecular mechanism remains to be elucidated. Purpose This study aims to identify novel genes and mechanisms involved in PAH development. Methods We performed DNA microarray analysis using RNA samples isolated from human ECs of various vascular beds (including lung microvessels) and organs (including lung). We subsequently searched for genes highly and specifically expressed in lung microvessels since these genes are likely involved in pulmonary circulation homeostasis maintenance. Once found, we confirmed its expressional changes during hypoxia in ECs and lung tissues. We next analyzed its role in EC functions using human pulmonary artery ECs (hPAECs) by in vitro angiogenesis assay, using both candidate gene overexpression via retrovirus transfection and treatment with its active form using appropriate recombinant protein. To explore the role of candidate gene in PAH development in vivo, we generated EC-specific knockout mice and transgenic mice in which the candidate gene is genetically deleted and activated in ECs, respectively. PAH was induced by chronic hypoxia exposure (10% O2- for 3 weeks). Lastly, to explore the underlying mechanisms, we analyzed expressional alterations in possible signaling pathways in ECs that could relate with the effect of the candidate gene. Results From microarray analysis, we identified inhibin Beta-A (INHBA) as a candidate gene that was highly and specifically expressed in human lung microvascular ECs. INHBA homo-dimerization is known to produce activin A (ActA), a TGF-beta superfamily member. Hypoxia exposure caused significant decrease of INHBA mRNA expression in ECs and mouse lung tissues. Both INHBA overexpression and ActA-treatment in hPAECs caused dramatic reduction of their angiogenic capacities (reduced migration and tube formation capability with increased apoptosis). In vivo, EC-specific INHBA overexpressing mice (VEcad-INHBA-TG) showed exacerbated hypoxia-induced PAH, assessed by higher right ventricular systolic pressure (RVSP) and more severely remodeled pulmonary arteries. By contrast, EC-specific INHBA knockout mice (INHBA-floxed/VEcad-Cre-TG) showed significant amelioration of PAH, shown by reduced RVSP and vascular remodeling. Furthermore, we found that INHBA overexpression and ActA-treatment induced a marked reduction of BMPRII, known to play pivotal roles in PAH, in hPAECs by accelerating its lysosomal degradation. Conclusion We identified a novel gene that is crucially involved in PAH development. INHBA and/or ActA negatively regulates EC functions potentially through its BMPRII-altering capability. Gain- and loss-of-function studies in mice revealed that INHBA pathways are promising therapeutic targets for the treatment of PAH.

2020 ◽  
Vol 318 (5) ◽  
pp. L1097-L1108 ◽  
Author(s):  
Stuti Agarwal ◽  
Himanshu Sharma ◽  
Ling Chen ◽  
Navneet K. Dhillon

We previously demonstrated that the combined exposure of human pulmonary microvascular endothelial cells (HPMECs) to morphine and viral protein(s) results in the oxidative stress-mediated induction of autophagy, leading to shift in the cells from early apoptotic to apoptosis-resistant proliferative status associated with the angioproliferative remodeling observed in pulmonary arterial hypertension (PAH). In this study, we tried to delineate the major source of HIV-1 protein Tat and morphine induced oxidative burst in HPMECs and its consequences on vascular remodeling and PAH in an in vivo model. We observed switch from the initial increased expression of NADPH oxidase (NOX) 2 in response to acute treatment of morphine and HIV-Tat to later increased expression of NOX4 on chronic treatment in the endoplasmic reticulum of HPMECs without any alterations in the mitochondria. Furthermore, NOX-dependent induction of autophagy was observed to play a pivotal role in regulating the endothelial cell survival. Our in vivo findings showed significant increase in pulmonary vascular remodeling, right ventricular systolic pressure, and Fulton index in HIV-transgenic rats on chronic administration of morphine. This was associated with increased oxidative stress in lung tissues and rat pulmonary microvascular endothelial cells. Additionally, endothelial cells from morphine-treated HIV-transgenic rats demonstrated increased expression of NOX2 and NOX4 proteins, inhibition of which ameliorated their increased survival upon serum starvation. In conclusion, this study describes NADPH oxidases as one of the main players in the oxidative stress-mediated endothelial dysfunction on the dual hit of HIV-viral protein(s) and opioids.


2020 ◽  
Vol 21 (11) ◽  
pp. 4130
Author(s):  
Maria Catalina Gomez-Puerto ◽  
Xiao-Qing Sun ◽  
Ingrid Schalij ◽  
Mar Orriols ◽  
Xiaoke Pan ◽  
...  

Pulmonary arterial hypertension (PAH) is a life-threatening disease characterized by obstructed pulmonary vasculatures. Current therapies for PAH are limited and only alleviate symptoms. Reduced levels of BMPR2 are associated with PAH pathophysiology. Moreover, reactive oxygen species, inflammation and autophagy have been shown to be hallmarks in PAH. We previously demonstrated that MnTBAP, a synthetic metalloporphyrin with antioxidant and anti-inflammatory activity, inhibits the turn-over of BMPR2 in human umbilical vein endothelial cells. Therefore, we hypothesized that MnTBAP might be used to treat PAH. Human pulmonary artery endothelial cells (PAECs), as well as pulmonary microvascular endothelial (MVECs) and smooth muscle cells (MVSMCs) from PAH patients, were treated with MnTBAP. In vivo, either saline or MnTBAP was given to PAH rats induced by Sugen 5416 and hypoxia (SuHx). On PAECs, MnTBAP was found to increase BMPR2 protein levels by blocking autophagy. Moreover, MnTBAP increased BMPR2 levels in pulmonary MVECs and MVSMCs isolated from PAH patients. In SuHx rats, MnTBAP reduced right ventricular (RV) afterload by reversing pulmonary vascular remodeling, including both intima and media layers. Furthermore, MnTBAP improved RV function and reversed RV dilation in SuHx rats. Taken together, these data highlight the importance of MnTBAP as a potential therapeutic treatment for PAH.


2020 ◽  
Vol 319 (2) ◽  
pp. H377-H391 ◽  
Author(s):  
Si Lei ◽  
Fei Peng ◽  
Mei-Lei Li ◽  
Wen-Bing Duan ◽  
Cai-Qin Peng ◽  
...  

Smooth muscle-enriched long noncoding RNA (SMILR), as a long noncoding RNA (lncRNA), was increased in pulmonary arterial hypertension (PAH) patients and in vitro and in vivo models. SMILR activated RhoA/ROCK signaling by targeting miR-141 to disinhibit its downstream target RhoA. SMILR knockdown or miR-141 overexpression inhibited hypoxia-induced cell proliferation and migration via repressing RhoA/ROCK signaling in pulmonary arterial smooth muscle cells (PASMCs), which was confirmed in vivo experiments that knockdown of SMILR inhibited vascular remodeling and alleviated PAH in rats. SMILR may be a promising and novel therapeutic target for the treatment and drug development of PAH.


2017 ◽  
Vol 7 (3) ◽  
pp. 643-653 ◽  
Author(s):  
Nura A. Mohamed ◽  
Robert P. Davies ◽  
Paul D. Lickiss ◽  
Blerina Ahmetaj-Shala ◽  
Daniel M. Reed ◽  
...  

Pulmonary arterial hypertension (PAH) is a progressive and debilitating condition. Despite promoting vasodilation, current drugs have a therapeutic window within which they are limited by systemic side effects. Nanomedicine uses nanoparticles to improve drug delivery and/or reduce side effects. We hypothesize that this approach could be used to deliver PAH drugs avoiding the systemic circulation. Here we report the use of iron metal organic framework (MOF) MIL-89 and PEGylated MIL-89 (MIL-89 PEG) as suitable carriers for PAH drugs. We assessed their effects on viability and inflammatory responses in a wide range of lung cells including endothelial cells grown from blood of donors with/without PAH. Both MOFs conformed to the predicted structures with MIL-89 PEG being more stable at room temperature. At concentrations up to 10 or 30 µg/mL, toxicity was only seen in pulmonary artery smooth muscle cells where both MOFs reduced cell viability and CXCL8 release. In endothelial cells from both control donors and PAH patients, both preparations inhibited the release of CXCL8 and endothelin-1 and in macrophages inhibited inducible nitric oxide synthase activity. Finally, MIL-89 was well-tolerated and accumulated in the rat lungs when given in vivo. Thus, the prototypes MIL-89 and MIL-89 PEG with core capacity suitable to accommodate PAH drugs are relatively non-toxic and may have the added advantage of being anti-inflammatory and reducing the release of endothelin-1. These data are consistent with the idea that these materials may not only be useful as drug carriers in PAH but also offer some therapeutic benefit in their own right.


2019 ◽  
Vol 9 (4) ◽  
pp. 204589401987859 ◽  
Author(s):  
Guosen Yan ◽  
Jinxia Wang ◽  
Tao Yi ◽  
Junfen Cheng ◽  
Haixu Guo ◽  
...  

Pulmonary arterial hypertension is a rapidly progressive and often fatal disease. As the pathogenesis of pulmonary arterial hypertension remains unclear, there is currently no good drug for pulmonary arterial hypertension and new therapy is desperately needed. This study investigated the effects and mechanism of baicalin on vascular remodeling in rats with pulmonary arterial hypertension. A rat pulmonary arterial hypertension model was constructed using intraperitoneal injection of monocrotaline, and different doses of baicalin were used to treat these rats. The mean pulmonary arterial pressure (mPAP) and right ventricular systolic pressure (RVSP) were measured with a right heart catheter. Moreover, the hearts were dissected to determine the right ventricular hypertrophy index (RVHI). The lung tissues were stained with H&E and Masson's staining to estimate the pulmonary vascular remodeling and collagen fibrosis, and the expression of proteins in the AKT, ERK, and NF-κB p65 phosphorylation (p-AKT, p-ERK, p-p65) was examined by Western blot analysis. We found that compared with untreated pulmonary arterial hypertension rats, baicalin ameliorated pulmonary vascular remodeling and cardiorespiratory injury, inhibited p-p65 and p-ERK expression, and promoted p-AKT and p-eNOS expression. In conclusion, baicalin interfered with pulmonary vascular remodeling and pulmonary arterial hypertension development in rats through the AKT/eNOS, ERK and NF-κB signaling pathways.


2020 ◽  
Vol 40 (11) ◽  
pp. 2605-2618
Author(s):  
Anne L. Theilmann ◽  
Lindsey G. Hawke ◽  
L. Rhiannon Hilton ◽  
Mara K.M. Whitford ◽  
Devon V. Cole ◽  
...  

Objective: Pulmonary arterial hypertension is a disease of proliferative vascular occlusion that is strongly linked to mutations in BMPR2 —the gene encoding the BMPR-II (BMP [bone morphogenetic protein] type II receptor). The endothelial-selective BMPR-II ligand, BMP9, reverses disease in animal models of pulmonary arterial hypertension and suppresses the proliferation of healthy endothelial cells. However, the impact of BMPR2 loss on the antiproliferative actions of BMP9 has yet to be assessed. Approach and Results: BMP9 suppressed proliferation in blood outgrowth endothelial cells from healthy control subjects but increased proliferation in blood outgrowth endothelial cells from pulmonary arterial hypertension patients with BMPR2 mutations. This shift from growth suppression to enhanced proliferation was recapitulated in control human pulmonary artery endothelial cells following siRNA-mediated BMPR2 silencing, as well as in mouse pulmonary endothelial cells isolated from endothelial-conditional Bmpr2 knockout mice ( Bmpr2 EC −/− ). BMP9-induced proliferation was not attributable to altered metabolic activity or elevated TGFβ (transforming growth factor beta) signaling but was linked to the prolonged induction of the canonical BMP target ID1 in the context of BMPR2 loss. In vivo, daily BMP9 administration to neonatal mice impaired both retinal and lung vascular patterning in control mice ( Bmpr2 EC+/+ ) but had no measurable effect on mice bearing a heterozygous endothelial Bmpr2 deletion ( Bmpr2 EC +/− ) and caused excessive angiogenesis in both vascular beds for Bmpr2 EC −/− mice. Conclusions: BMPR2 loss reverses the endothelial response to BMP9, causing enhanced proliferation. This finding has potential implications for the proposed translation of BMP9 as a treatment for pulmonary arterial hypertension and suggests the need for focused patient selection in clinical trials.


2017 ◽  
Vol 7 (2) ◽  
pp. 285-299 ◽  
Author(s):  
Olivier Boucherat ◽  
Geraldine Vitry ◽  
Isabelle Trinh ◽  
Roxane Paulin ◽  
Steeve Provencher ◽  
...  

Pulmonary arterial hypertension (PAH) remains a mysterious killer that, like cancer, is characterized by tremendous complexity. PAH development occurs under sustained and persistent environmental stress, such as inflammation, shear stress, pseudo-hypoxia, and more. After inducing an initial death of the endothelial cells, these environmental stresses contribute with time to the development of hyper-proliferative and apoptotic resistant clone of cells including pulmonary artery smooth muscle cells, fibroblasts, and even pulmonary artery endothelial cells allowing vascular remodeling and PAH development. Molecularly, these cells exhibit many features common to cancer cells offering the opportunity to exploit therapeutic strategies used in cancer to treat PAH. In this review, we outline the signaling pathways and mechanisms described in cancer that drive PAH cells’ survival and proliferation and discuss the therapeutic potential of antineoplastic drugs in PAH.


2007 ◽  
Vol 293 (3) ◽  
pp. L548-L554 ◽  
Author(s):  
Fares A. Masri ◽  
Weiling Xu ◽  
Suzy A. A. Comhair ◽  
Kewal Asosingh ◽  
Michelle Koo ◽  
...  

Idiopathic pulmonary arterial hypertension (IPAH) is characterized by plexiform vascular lesions, which are hypothesized to arise from deregulated growth of pulmonary artery endothelial cells (PAEC). Here, functional and molecular differences among PAEC derived from IPAH and control human lungs were evaluated. Compared with control cells, IPAH PAEC had greater cell numbers in response to growth factors in culture due to increased proliferation as determined by bromodeoxyuridine incorporation and Ki67 nuclear antigen expression and decreased apoptosis as determined by caspase-3 activation and TdT-mediated dUTP nick end labeling assay. IPAH cells had greater migration than control cells but less organized tube formation in in vitro angiogenesis assay. Persistent activation of signal transducer and activator of transcription 3 (STAT3), a regulator of cell survival and angiogenesis, and increased expression of its downstream prosurvival target, Mcl-1, were identified in IPAH PAEC. A Janus kinase (JAK) selective inhibitor reduced STAT3 activation and blocked proliferation of IPAH cells. Phosphorylated STAT3 was detected in endothelial cells of IPAH lesions in vivo, suggesting that STAT3 activation plays a role in the proliferative pulmonary vascular lesions in IPAH lungs.


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