scholarly journals Endothelial PHD2 Deficiency Induces Nitrative Stress via Suppression of Caveolin-1 in Pulmonary Arterial Hypertension

2021 ◽  
Author(s):  
Bin Liu ◽  
Dan Yi ◽  
Jingbo Dai ◽  
Yi Peng ◽  
Rebecca Vanderpool ◽  
...  

Nitrative stress is a characteristic feature of the pathology of human pulmonary arterial hypertension (PAH). However, the role of nitrative stress in the pathogenesis of obliterative vascular remolding and severe PAH remains largely unclear. Our recent studies identified a novel mouse model (Egln1Tie2Cre, Egln1 encoding prolyl hydroxylase 2 [PHD2]) with obliterative vascular remodeling and right heart failure, which provides us an excellent model to study the role of nitrative stress in obliterative vascular remodeling. Here we show that nitrative stress was markedly elevated whereas endothelial Caveolin-1 (Cav1) expression was suppressed in the lungs of Egln1Tie2Cre mice. ROS scavenger manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride (MnTmPyP) treatment inhibited obliterative pulmonary vascular remodeling and suppressed severe PAH in Egln1Tie2Cre mice. Genetic restoration of endothelial Cav1 expression in Egln1Tie2Cre mice normalized nitrative stress, reduced PAH and improved right heart function. These data suggest that suppression of endothelial Cav1 expression secondary to PHD2 deficiency augments nitrative stress, which contributes to obliterative vascular remodeling and severe PAH. Thus, ROS scavenger might have great therapeutic potential for the inhibition of obliterative vascular remodeling and severe PAH.

2016 ◽  
Vol 64 (4) ◽  
pp. 969.1-969 ◽  
Author(s):  
JR Sysol ◽  
J Chen ◽  
S Singla ◽  
V Natarajan ◽  
RF Machado ◽  
...  

RationalePulmonary arterial hypertension (PAH) is a severe, progressive disease characterized by increased pulmonary arterial pressure and resistance due in part to uncontrolled vascular remodeling. The mechanisms contributing to vascular remodeling in PAH are poorly understood and involve rampant pulmonary artery smooth muscle cell (PASMC) proliferation. We recently demonstrated the important role of sphingosine kinase 1 (SphK1), a lipid kinase producing pro-proliferative sphingosine-1-phosphate (S1P), in the development of pulmonary vascular remodeling in PAH. However, the regulatory processes involved in upregulation of SphK1 in this disease are unknown.ObjectiveIn this study, we aimed to identify novel molecular mechanisms governing the regulation of SphK1 expression, with a focus on microRNA (miR). Using both in vitro studies in pulmonary artery smooth muscle cells (PASMCs) and an in vivo mouse model of experimental hypoxia-mediated pulmonary hypertension (HPH), we explored the role of miR in controlling SphK1 expression in the development of pulmonary vascular remodeling.Methods and ResultsIn silico analysis identified hsa-miR-1-3p (miR-1) as a candidate targeting SphK1. We demonstrate miR-1 is down-regulated by hypoxia in human PASMCs and in lung tissues of mice with HPH, coinciding with upregulation of SphK1 expression. PASMCs isolated from patients with PAH had significantly reduced expression of miR-1. Transfection of human PASMCs with miR-1 mimics significantly attenuated activity of a SphK1-3'-UTR luciferase reporter construct and SphK1 protein expression. miR-1 overexpression in human PASMCs also inhibited proliferation and migration under normoxic and hypoxic conditions, both important in pathogenic vascular remodeling in PAH. Finally, we demonstrated that intravenous administration of miR-1 mimics prevents the development of experimental HPH in mice and attenuates induction of SphK1 in PASMCs.ConclusionThese data demonstrate that miR-1 expression in reduced in PASMCs from PAH patients, is modulated by hypoxia, and regulates the expression of SphK1. Key phenotypic aspects of vascular remodeling are influenced by miR-1 and its overexpression can prevent the development of HPH in mice. These studies further our understanding of the mechanisms underlying pathogenic pulmonary vascular remodeling in PAH and could lead to novel therapeutic targets.Supported by grants NIH/NHLBI R01 HL127342 and R01 HL111656 to RFM, NIH/NHLBI P01 HL98050 and R01 HL127342 to VN, American Heart Association Predoctoral Fellowship (15PRE2190004) to JRS, and NIH/NLHBI NRSA F30 Fellowship (FHL128034A) to JRS.


2020 ◽  
Vol 318 (4) ◽  
pp. H853-H866 ◽  
Author(s):  
Yin Kang ◽  
Guangyan Zhang ◽  
Emma C. Huang ◽  
Jiapeng Huang ◽  
Jun Cai ◽  
...  

Right ventricular (RV) dysfunction is the main determinant of mortality in patients with pulmonary arterial hypertension (PAH) and while inflammation is pathogenic in PAH, there is limited information on the role of RV inflammation in PAH. Sulforaphane (SFN), a potent Nrf2 activator, has significant anti-inflammatory effects and facilitates cardiac protection in preclinical diabetic models. Therefore, we hypothesized that SFN might play a comparable role in reducing RV and pulmonary inflammation and injury in a murine PAH model. We induced PAH using SU5416 and 10% hypoxia (SuHx) for 4 wk in male mice randomized to SFN at a daily dose of 0.5 mg/kg 5 days per week for 4 wk or to vehicle control. Transthoracic echocardiography was performed to characterize chamber-specific ventricular function during PAH induction. At 4 wk, we measured RV pressure and relevant measures of histology and protein and gene expression. SuHx induced progressive RV, but not LV, diastolic and systolic dysfunction, and RV and pulmonary remodeling, fibrosis, and inflammation. SFN prevented SuHx-induced RV dysfunction and remodeling, reduced RV inflammation and fibrosis, upregulated Nrf2 expression and its downstream gene NQO1, and reduced the inflammatory mediator leucine-rich repeat and pyrin domain-containing 3 (NLRP3). SFN also reduced SuHx-induced pulmonary vascular remodeling, inflammation, and fibrosis. SFN alone had no effect on the heart or lungs. Thus, SuHx-induced RV and pulmonary dysfunction, inflammation, and fibrosis can be attenuated or prevented by SFN, supporting the rationale for further studies to investigate SFN and the role of Nrf2 and NLRP3 pathways in preclinical and clinical PAH studies. NEW & NOTEWORTHY Pulmonary arterial hypertension (PAH) in this murine model (SU5416 + hypoxia) is associated with early changes in right ventricular (RV) diastolic and systolic function. RV and lung injury in the SU5416 + hypoxia model are associated with markers for fibrosis, inflammation, and oxidative stress. Sulforaphane (SFN) alone for 4 wk has no effect on the murine heart or lungs. Sulforaphane (SFN) attenuates or prevents the RV and lung injury in the SUF5416 + hypoxia model of PAH, suggesting that Nrf2 may be a candidate target for strategies to prevent or reverse PAH.


2010 ◽  
Vol 49 ◽  
pp. S31
Author(s):  
Florian Veit ◽  
Bakytbek Egemnazarov ◽  
Hossein Ardeschir Ghofrani ◽  
Ralph Theo Schermuly ◽  
Werner Seeger ◽  
...  

2016 ◽  
Vol 88 (9) ◽  
pp. 65-70
Author(s):  
V A Nevzorova ◽  
E A Kochetkova ◽  
L G Ugay ◽  
Yu V Maistrovskaya ◽  
E A Khludeeva

Aim. To define the role of circulating biomarkers for the metabolism of collagen and intercellular substance and vascular remodeling in the development of osteoporosis (OP) in idiopathic pulmonary arterial hypertension (IPAH). Materials and methods. Functional hemodynamic parameters, bone mineral density (BMD) in the lumbar spine and femoral neck and the serum levels of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), MMP-9/TIMP-1 complex, C-terminal telopeptide of collagen type 1 (CITP), and endothelin-1 (ET-1) were determined in 27 high-risk IPAH patients and 30 healthy volunteers. Results. OP in IPAH was detected in 50% of the examinees. The serum levels of CITP, MMP-9, TIMP-1, and ET-1 proved to be higher in the high-risk IPAH patients than in the healthy volunteers. There was a direct correlation between BMD and six-minute walk test and an inverse correlation with total pulmonary vascular resistance (TPVR). Serum TMIP-1 levels correlated with cardiac index and TPVR; ET-1 concentrations were directly related to pulmonary artery systolic pressure, cardiac index, and TPVR. Inverse relationships were found between BMD and circulating CITP, MMP-9, TMIP-1, MMP-9/TMIP-1, and ET-1. At the same time, there was only a tendency towards a positive correlation between serum CITP and ET-1 concentrations. Conclusion. The results of the investigation confirm that endothelin system dysregulation plays a leading role in the development of persistent hemodynamic disorders in high-risk IPAH and suggest that it is involved in the development of osteopenic syndrome. Enhanced ET-1 secretion initiates bone loss possibly via activation of connective tissue matrix destruction.


2021 ◽  
Vol 10 (13) ◽  
pp. 2826
Author(s):  
Ioannis T. Farmakis ◽  
Eftychia Demerouti ◽  
Panagiotis Karyofyllis ◽  
George Karatasakis ◽  
Maria Stratinaki ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by an insult in the pulmonary vasculature, with subsequent right ventricular (RV) adaptation to the increased afterload that ultimately leads to RV failure. The awareness of the importance of RV function in PAH has increased considerably because right heart failure is the predominant cause of death in PAH patients. Given its wide availability and reduced cost, echocardiography is of paramount importance in the evaluation of the right heart in PAH. Several echocardiographic parameters have been shown to have prognostic implications in PAH; however, the role of echocardiography in the risk assessment of the PAH patient is limited under the current guidelines. This review discusses the echocardiographic evaluation of the RV in PAH and during therapy, and its prognostic implications, as well as the potential significant role of repeated echocardiographic assessment in the follow-up of patients with PAH.


2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Ruby A. Fernandez ◽  
Premanand Sundivakkam ◽  
Kimberly A. Smith ◽  
Amy S. Zeifman ◽  
Abigail R. Drennan ◽  
...  

Pulmonary circulation is an important circulatory system in which the body brings in oxygen. Pulmonary arterial hypertension (PAH) is a progressive and fatal disease that predominantly affects women. Sustained pulmonary vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness are the major causes for the elevated pulmonary vascular resistance (PVR) in patients with PAH. The elevated PVR causes an increase in afterload in the right ventricle, leading to right ventricular hypertrophy, right heart failure, and eventually death. Understanding the pathogenic mechanisms of PAH is important for developing more effective therapeutic approach for the disease. An increase in cytosolic free Ca2+ concentration ([Ca2+]cyt) in pulmonary arterial smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for PASMC migration and proliferation which lead to pulmonary vascular wall thickening and remodeling. It is thus pertinent to define the pathogenic role of Ca2+ signaling in pulmonary vasoconstriction and PASMC proliferation to develop new therapies for PAH. [Ca2+]cyt in PASMC is increased by Ca2+ influx through Ca2+ channels in the plasma membrane and by Ca2+ release or mobilization from the intracellular stores, such as sarcoplasmic reticulum (SR) or endoplasmic reticulum (ER). There are two Ca2+ entry pathways, voltage-dependent Ca2+ influx through voltage-dependent Ca2+ channels (VDCC) and voltage-independent Ca2+ influx through store-operated Ca2+ channels (SOC) and receptor-operated Ca2+ channels (ROC). This paper will focus on the potential role of VDCC, SOC, and ROC in the development and progression of sustained pulmonary vasoconstriction and excessive pulmonary vascular remodeling in PAH.


2012 ◽  
Vol 302 (8) ◽  
pp. H1546-H1562 ◽  
Author(s):  
Frank K. Kuhr ◽  
Kimberly A. Smith ◽  
Michael Y. Song ◽  
Irena Levitan ◽  
Jason X-J. Yuan

Pulmonary arterial hypertension (PAH) is a severe and progressive disease that usually culminates in right heart failure and death if left untreated. Although there have been substantial improvements in our understanding and significant advances in the management of this disease, there is a grim prognosis for patients in the advanced stages of PAH. A major cause of PAH is increased pulmonary vascular resistance, which results from sustained vasoconstriction, excessive pulmonary vascular remodeling, in situ thrombosis, and increased pulmonary vascular stiffness. In addition to other signal transduction pathways, Ca2+ signaling in pulmonary artery smooth muscle cells (PASMCs) plays a central role in the development and progression of PAH because of its involvement in both vasoconstriction, through its pivotal effect of PASMC contraction, and vascular remodeling, through its stimulatory effect on PASMC proliferation. Altered expression, function, and regulation of ion channels and transporters in PASMCs contribute to an increased cytosolic Ca2+ concentration and enhanced Ca2+ signaling in patients with PAH. This review will focus on the potential pathogenic role of Ca2+ mobilization, regulation, and signaling in the development and progression of PAH.


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