Abstract 13932: Lung-targeted Sin3a Gene Therapy as a Promising Strategy to Restore Bmpr2 Expression in Pulmonary Arterial Hypertension

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Malik Bisserier ◽  
Prabhu Mathiyalagan ◽  
Yassine Abdeldjebbar ◽  
Shihong Zhang ◽  
Firas Elmastour ◽  
...  

Background: Pulmonary arterial hypertension (PAH) is a fatal lung disease of multifactorial etiology, with no curative treatment. Several studies have previously suggested that hypermethylation of the BMPR2 promoter may be associated with gene repression and disease progression. However, the underlying mechanisms have yet to be discovered. Sin3A/B (Switch-Independent 3) plays a critical role in the transcriptional regulation of genes through various epigenetic mechanisms. Here, we investigated for the first time the role of SIN3a in the regulation of BMPR2 methylation and expression in PAH. Methods: Expression of SIN3a was analyzed by qRT-PCR and western blot in lung tissues from PAH patients and rodent models of PAH. Using a gain- and loss-of-function approach, we investigated the role of SIN3a on cell proliferation (BrdU assay) and migration (Boyden chamber assay), and BMPR2 levels in primary human pulmonary arterial smooth muscle cells (hPASMC) and endothelial cells (hPAEC). The methylation level was analyzed by MS-PCR. The therapeutic potential of SIN3a was tested in vivo in the Sugen/Hypoxia (SuHx) mouse and monocrotaline (MCT) rat models of PAH using an adeno-associated virus 1 encoding human SIN3a. Results: We found a significant downregulation of SIN3a expression in the lung samples from PAH patients, SuHx mice, and MCT rats. In hPASMC and hPAEC, our results showed that SIN3a inhibits cell proliferation, migration, and upregulates BMPR2 through two distinct pathways. In hPASMC, our data showed that SIN3a upregulates BMPR2 expression by inhibiting the methylation level of the BMPR2 promoter. In hPAEC, SIN3a restored BMPR2 expression independently of the methylation status by upregulating the FOXK2 transcription factor. In vivo , our results showed that restoring SIN3a expression by gene therapy significantly decreased MCT- and SuHx-induced PAH as illustrated by decreased vascular and RV remodeling, hypertrophy, PAP and RVSP. Conclusions: Altogether, our study revealed that SIN3a plays a critical role in the regulation of BMPR2 expression by modulating the lung epigenetic landscape. Additionally, our study identifies lung-targeted SIN3a gene therapy as a new promising therapeutic strategy for treating PAH patients.

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Anastasia Gorelova ◽  
Sanghamitra Sahoo ◽  
Patrick J Pagano

Pulmonary arterial hypertension (PAH) is a poorly characterized disease of unclear etiology that affects individuals of all ages. Vascular remodeling and increase in pulmonary artery (PA) and right ventricle (RV) pressures are two major culprits in RV failure and death in PAH. Recent advances in the study of PAH suggest that endothelial cell proliferation is an early instigator of this hallmark remodeling. We postulated that Axl receptor tyrosine kinase (implicated in pro-proliferative and pro-survival signaling in cancerous cells) could mediate endothelial proliferation and thus hemodynamic changes occurring in PAH. Using immunofluorescent microscopy of lung microvessels of human PAH vs. non-PAH, we observed Axl expression on intimal endothelial cells but not medial smooth muscle cells. Furthermore, digitized microscopy revealed that Axl tended to increase on the endothelium of PAH vessels (1.65±0.15-fold vs. non-PAH; n=3-4; p=0.057 ). To address the role of Axl in vivo , an Axl inhibitor R428 was employed in a mouse model of pulmonary hypertension. C57Bl/6 mice were subjected to hypoxia at pO 2 =10% and VEGF receptor antagonist SU5416 (Su/Ch) or normoxia (Norm) for 3 wks. Indeed, Su/Ch caused a significant rise in lung Axl protein and mRNA (7.1±0.4- and 2.4±0.5-fold, Su/Ch vs. Norm, protein and mRNA, respectively; n=3-6; p<0.01). As predicted, RV pressure (RVP) rose from 27±0.5 to 43±1.8 mmHg (Norm vs. Su/Ch; n=6; p<0.01). However, we did not observe a decrease in RVP with twice-daily gavage of 75 mg/kg R428 (43±1.4 mmHg, Su/Ch + R428; n=6). A similar pattern was observed with mean PA pressure (18.4±0.3 and 28.7±1.2 mmHg, Norm vs. Su/Ch, p<0.01; 28.7±0.9 mmHg, Su/Ch + R428), RV resistance (1403±256 vs. 2703±464 Wood units, Norm vs. Su/Ch, n/s; vs. 3610±625 Wood units, Su/Ch + R428) and Fulton index (0.26±0.01 and 0.34±0.02, Norm vs. Su/Ch, p<0.05; 0.38±0.02, Su/Ch + R428). In conclusion, our preliminary results demonstrate upregulated Axl expression in the endothelium of PAH patients and in lungs of PH mice and suggest that Axl kinase may play a novel role in pulmonary vascular endothelial proliferation and remodeling in PAH. It remains to be determined whether drug bioavailability or severity of disease precluded an ameliorative effect of an Axl inhibitor.


2017 ◽  
Vol 26 (146) ◽  
pp. 170093 ◽  
Author(s):  
Anna R. Hemnes ◽  
Marc Humbert

The pathobiology of pulmonary arterial hypertension (PAH) is complex and incompletely understood. Although three pathogenic pathways have been relatively well characterised, it is widely accepted that dysfunction in a multitude of other cellular processes is likely to play a critical role in driving the development of PAH. Currently available therapies, which all target one of the three well-characterised pathways, provide significant benefits for patients; however, PAH remains a progressive and ultimately fatal disease. The development of drugs to target alternative pathogenic pathways is, therefore, an attractive proposition and one that may complement existing treatment regimens to improve outcomes for patients. Considerable research has been undertaken to identify the role of the less well-understood pathways and in this review we will highlight some of the key discoveries and the potential for utility as therapeutic targets.


2020 ◽  
Vol 10 (4) ◽  
pp. 204589402097491
Author(s):  
Zhenhua Wu ◽  
Jie Geng ◽  
Yujuan Qi ◽  
Jian Li ◽  
Yaobang Bai ◽  
...  

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease associated with dysfunction of pulmonary artery endothelial cells and pulmonary artery smooth muscle cells (PASMCs). To explore the potential mechanism of miR-193-3p in pulmonary arterial hypertension, human PASMCs and rats were respectively stimulated by hypoxia and monocrotaline to establish PAH model in vivo and in vitro. The expressions of miR-193-3p and p21-activated protein kinase 4 (PAK4) in the lung samples of PAH patients and paired healthy samples from the healthy subjects in PHA cells and rats were detected by quantitative reverse transcriptase-PCR. Morphological changes in lung tissues were determined using hematoxylin and eosin staining. Right ventricular systolic pressure (RVSP) and ratio of right ventricle to left ventricle plus septum (RV/LV p S) were measured. The binding relationship between miR-193-3p and PAK4 was analyzed by TargetScan and verified by luciferase reporter assay. Cell viability, apoptosis, and migration were detected by 3-(4, 5-Dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide (MTT) flow cytometry, and wound-healing assays, respectively. The protein expressions of PAK4, proliferating cell nuclear antigen (PCNA), P21, p-AKT, and AKT in vivo or in vitro were determined by Western blot. In this study, we found that in pulmonary arterial hypertension, miR-193-3p expression was downregulated and PAK4 expression was up-regulated. MiR-193-3p directly targeted PAK4 and negatively regulated its expression. Hypoxia condition promoted cell proliferation, migration, and inhibited apoptosis accompanied with increased expressions of PCNA and p-AKT/AKT and decreased expression of P21 in PASMCs. MiR-193-3p overexpression attenuated the effects of hypoxia on PASMCs via downregulating PAK4. Monocrotaline treatment increased p-AKT/AKT and decreased P21 expression and caused pulmonary vascular remodeling in the model rats. MiR-193-3p overexpression attenuated pulmonary vascular remodeling, decreased p-AKT/AKT, and increased P21 levels via downregulating PAK4 in monocrotaline-induced rats. The results in this study demonstrated that upregulation of miR-193-3p reduced cell proliferation, migration, and apoptosis of PAH in vitro and pulmonary vascular remodeling in PAH in vivo through downregulating PAK4.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tatyana Novoyatleva ◽  
Nabham Rai ◽  
Baktybek Kojonazarov ◽  
Swathi Veeroju ◽  
Isabel Ben-Batalla ◽  
...  

AbstractPulmonary arterial hypertension (PAH), is a fatal disease characterized by a pseudo-malignant phenotype. We investigated the expression and the role of the receptor tyrosine kinase Axl in experimental (i.e., monocrotaline and Su5416/hypoxia treated rats) and clinical PAH. In vitro Axl inhibition by R428 and Axl knock-down inhibited growth factor-driven proliferation and migration of non-PAH and PAH PASMCs. Conversely, Axl overexpression conferred a growth advantage. Axl declined in PAECs of PAH patients. Axl blockage inhibited BMP9 signaling and increased PAEC apoptosis, while BMP9 induced Axl phosphorylation. Gas6 induced SMAD1/5/8 phosphorylation and ID1/ID2 increase were blunted by BMP signaling obstruction. Axl association with BMPR2 was facilitated by Gas6/BMP9 stimulation and diminished by R428. In vivo R428 aggravated right ventricular hypertrophy and dysfunction, abrogated BMPR2 signaling, elevated pulmonary endothelial cell apoptosis and loss. Together, Axl is a key regulator of endothelial BMPR2 signaling and potential determinant of PAH.


2016 ◽  
Vol 48 (4) ◽  
pp. 1137-1149 ◽  
Author(s):  
Swati Dabral ◽  
Xia Tian ◽  
Baktybek Kojonazarov ◽  
Rajkumar Savai ◽  
Hossein Ardeschir Ghofrani ◽  
...  

Pulmonary arterial hypertension (PAH) is characterised by excessive pulmonary vascular remodelling involving deregulated proliferation of cells in intima, media as well as adventitia. Pulmonary arterial endothelial cell (PAEC) hyperproliferation and survival underlies the endothelial pathobiology of the disease.The indispensable involvement of Notch1 in the arterial endothelial phenotype and angiogenesis provides intriguing prospects for its involvement in the pathogenesis of PAH.We observed an increased expression of Notch1 in lungs of idiopathic PAH (IPAH) patients and hypoxia/SU5416 (SUHx) rats compared with healthy subjects. In vitro loss- and gain-of-function studies demonstrated that Notch1 increased proliferation of human PAECs (hPAECs) via downregulation of p21 and inhibited apoptosis via Bcl-2 and Survivin. Inhibition of Notch signalling using the γ-secretase inhibitor dibenzazepine dose-dependently decreased proliferation and migration of hPAECs. Notably, Notch1 expression and transcriptional activity were increased under hypoxia in hPAECs and knockdown of Notch1 inhibited hypoxia-induced proliferation of the cells. Furthermore, in vivo treatment with a γ-secretase inhibitor (AMG2008827) significantly reduced the right ventricular systolic pressure and right heart hypertrophy in SUHx rats.Here, we conclude that Notch1 plays a critical role in PAH and Notch inhibitors may be a promising therapeutic option for PAH.


2020 ◽  
Author(s):  
Giusy Russomanno ◽  
Kyeong Beom Jo ◽  
Vahitha B. Abdul-Salam ◽  
Claire Morgan ◽  
Mai Alzaydi ◽  
...  

ABSTRACTEndothelial dysfunction contributes to the vascular pathology in pulmonary arterial hypertension (PAH). Circulating levels of endothelial miR-150 are reduced in PAH and act as an independent predictor of patient survival. The role of endothelial miR-150 in vascular dysfunction in PAH is not well understood.Endothelium-targeted miR-150 delivery prevented the disease in Sugen/hypoxia mice, while endothelial knockdown of miR-150 had adverse effects. miR-150 target genes revealed significant associations with PAH pathways, including proliferation, inflammation and phospholipid signaling, with PTEN-like mitochondrial phosphatase (PTPMT1) most markedly altered. PTPMT1 reduced inflammation, apoptosis and improved mitochondrial function in human pulmonary endothelial cells and blood-derived endothelial colony forming cells (ECFCs) from idiopathic PAH. Beneficial effects of miR-150 in vitro and in vivo were linked with PTPMT1-dependent biosynthesis of mitochondrial phospholipid cardiolipin and reduced expression of pro-apoptotic, pro-inflammatory and pro-fibrotic genes, including c-MYB, NOTCH3, TGF-β and Col1a1.In conclusion, we are first to show that miR-150-PTPMT1-cardiolipin pathway attenuates pulmonary endothelial damage induced by vascular stresses and may be considered as a potential therapeutic strategy in PAH.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1892
Author(s):  
Yun Han ◽  
Md Khadem Ali ◽  
Kamal Dua ◽  
Edda Spiekerkoetter ◽  
Yuqiang Mao

Pulmonary arterial hypertension (PAH) is a debilitating condition of the pulmonary circulatory system that occurs in patients of all ages and if untreated, eventually leads to right heart failure and death. Despite existing medical treatment options that improve survival and quality of life, the disease remains incurable. Thus, there is an urgent need to develop novel therapies to treat this disease. Emerging evidence suggests that long non-coding RNAs (lncRNAs) play critical roles in pulmonary vascular remodeling and PAH. LncRNAs are implicated in pulmonary arterial endothelial dysfunction by modulating endothelial cell proliferation, angiogenesis, endothelial mesenchymal transition, and metabolism. LncRNAs are also involved in inducing different pulmonary arterial vascular smooth muscle cell phenotypes, such as cell proliferation, apoptosis, migration, regulation of the phenotypic switching, and cell cycle. LncRNAs are essential regulators of gene expression that affect various diseases at the chromatin, transcriptional, post-translational, and even post-translational levels. Here, we focus on the role of LncRNAs and their molecular mechanisms in the pathogenesis of PAH. We also discuss the current research challenge and potential biomarker and therapeutic potentials of lncRNAs in PAH.


2016 ◽  
Vol 15 (1) ◽  
pp. 12-13
Author(s):  
Adaani E. Frost ◽  
Harrison W. Farber

Dramatic advances in therapy for pulmonary arterial hypertension (PAH) in the last 20 years have improved survival from a median of 2.5 years in the pretreatment era to 7.5 years currently. However, impressive as that may seem, it is important to note that a median survival of 7.5 years is equivalent to that of surgically resected non-small cell lung cancer, thus underscoring the importance of lung transplantation as a treatment option in patients with PAH. In this edition of Advances, Edelman has reviewed the pathway to transplantation for patients with PAH, detailing the recommendations for timing of referral, listing for lung transplantation, the role of the lung allocation score in allocating a donor organ, and the outcome of lung transplantation.


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