Role of Progenitor Cells in Pulmonary Vascular Remodeling

Author(s):  
Kurt R. Stenmark ◽  
Susan M. Majka ◽  
Maria G. Frid
2017 ◽  
Vol 313 (5) ◽  
pp. L899-L915 ◽  
Author(s):  
Fumiaki Kato ◽  
Seiichiro Sakao ◽  
Takao Takeuchi ◽  
Toshio Suzuki ◽  
Rintaro Nishimura ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by progressive obstructive remodeling of pulmonary arteries. However, no reports have described the causative role of the autophagic pathway in pulmonary vascular endothelial cell (EC) alterations associated with PAH. This study investigated the time-dependent role of the autophagic pathway in pulmonary vascular ECs and pulmonary vascular EC kinesis in a severe PAH rat model (Sugen/hypoxia rat) and evaluated whether timely induction of the autophagic pathway by rapamycin improves PAH. Hemodynamic and histological examinations as well as flow cytometry of pulmonary vascular EC-related autophagic pathways and pulmonary vascular EC kinetics in lung cell suspensions were performed. The time-dependent and therapeutic effects of rapamycin on the autophagic pathway were also assessed. Sugen/hypoxia rats treated with the vascular endothelial growth factor receptor blocker SU5416 showed increased right ventricular systolic pressure (RVSP) and numbers of obstructive vessels due to increased pulmonary vascular remodeling. The expression of the autophagic marker LC3 in ECs also changed in a time-dependent manner, in parallel with proliferation and apoptotic markers as assessed by flow cytometry. These results suggest the presence of cross talk between pulmonary vascular remodeling and the autophagic pathway, especially in small vascular lesions. Moreover, treatment of Sugen/hypoxia rats with rapamycin after SU5416 injection activated the autophagic pathway and improved the balance between cell proliferation and apoptosis in pulmonary vascular ECs to reduce RVSP and pulmonary vascular remodeling. These results suggested that the autophagic pathway can suppress PAH progression and that rapamycin-dependent activation of the autophagic pathway could ameliorate 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.


2016 ◽  
Vol 113 (31) ◽  
pp. 8801-8806 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Alexi Crosby ◽  
David Macias ◽  
Cristina Branco ◽  
Renato D. D. R. Colaço ◽  
...  

Hypoxic pulmonary vasoconstriction is correlated with pulmonary vascular remodeling. The hypoxia-inducible transcription factors (HIFs) HIF-1α and HIF-2α are known to contribute to the process of hypoxic pulmonary vascular remodeling; however, the specific role of pulmonary endothelial HIF expression in this process, and in the physiological process of vasoconstriction in response to hypoxia, remains unclear. Here we show that pulmonary endothelial HIF-2α is a critical regulator of hypoxia-induced pulmonary arterial hypertension. The rise in right ventricular systolic pressure (RVSP) normally observed following chronic hypoxic exposure was absent in mice with pulmonary endothelial HIF-2α deletion. The RVSP of mice lacking HIF-2α in pulmonary endothelium after exposure to hypoxia was not significantly different from normoxic WT mice and much lower than the RVSP values seen in WT littermate controls and mice with pulmonary endothelial deletion of HIF-1α exposed to hypoxia. Endothelial HIF-2α deletion also protected mice from hypoxia remodeling. Pulmonary endothelial deletion of arginase-1, a downstream target of HIF-2α, likewise attenuated many of the pathophysiological symptoms associated with hypoxic pulmonary hypertension. We propose a mechanism whereby chronic hypoxia enhances HIF-2α stability, which causes increased arginase expression and dysregulates normal vascular NO homeostasis. These data offer new insight into the role of pulmonary endothelial HIF-2α in regulating the pulmonary vascular response to hypoxia.


2004 ◽  
Vol 10 (5) ◽  
pp. S191
Author(s):  
Satoh Kimio ◽  
Karibe Akihiko ◽  
Sakuma Masahito ◽  
Kagaya Yutaka ◽  
Watanabe Jun ◽  
...  

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Aidan Hannon ◽  
Jia-Rong Jheng ◽  
Gunner Halliday ◽  
Yen-Chun Lai

Background: Pulmonary hypertension in heart failure with preserved ejection fraction (PH-HFpEF) is the most common cause of PH worldwide. It is closely linked to risk factors for metabolic syndrome, including obesity and diabetes - factors known to increase proliferation and migration of pulmonary artery smooth muscle cells (PASMCs), leading to pulmonary vascular remodeling. Qualitative studies have shown that patients with progressive vascular abnormalities develop more severe symptoms and suffer frequent hospitalization. However, underlying mechanisms involved in the regulation of pulmonary vascular remodeling in metabolic syndrome-associated PH-HFpEF are still unclear. Aim: We have recently observed decreased levels of the tumor suppressor WW domain-containing oxidoreductase (WWOX), which plays a housekeeping role in repressing cellular proliferation, in PASMCs isolated from rats with experimental PH-HFpEF and human subjects with obesity and diabetes. As microRNAs (miRNAs) have been shown to regulate WWOX expression in cancers, here we aimed at examining the involvement of miRNAs in WWOX-associated pulmonary vasculature regulation in metabolic syndrome-associated PH-HFpEF. Methods and Results: Among miRNAs that have been associated with reduced WWOX expression, including miR -134-5p, -153-3p, -29a-3b, -29b-3p and -187-5p, we found that miR-134-5p was significantly increased in PASMCs of obese and diabetic subjects. To determine the role of miR-134-5p in the regulation of WWOX in the pulmonary vasculature, we applied exogenous miR-134-5p to human PASMCs. Treatment with miR-134-5p decreased WWOX expression, increased PCNA expression (a cell proliferation marker) and enhanced cellular proliferation. Additionally, human PASMCs challenged with high concentration of glucose, palmitic acid and insulin, which mimic hyperglycemic, hyperlipidemic and hyperinsulinemic conditions, exhibited increased miR-134-5p, accompanied by elevated cellular proliferation.  Conclusions: These studies suggest that miR-134-5p may have a potential role in metabolic syndrome-associated PH-HFpEF through regulating WWOX in the pulmonary vasculature. These studies identify miR-134-5p as a potential therapeutic target for the treatment of metabolic syndrome-associated PH-HFpEF. This project was funded, in part, with support from the NIH NHLBI Short-Term Training Program in Biomedical Sciences Grant funded, in part by T35HL110854 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.


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.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Benjamin Keserü ◽  
Beate Fisslthaler ◽  
Ingrid Fleming

The soluble epoxide hydrolase (sEH), which is expressed in pulmonary artery smooth muscle cells, metabolizes cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) to their less active diols. Preliminary findings indicate a role of the sEH on hypoxic pulmonary vasoconstriction (HPV) and a vasoconstrictor role of EETs in the pulmonary vasculature. Here we assessed the influence of hypoxia on the expression of the sEH, acute HPV and pulmonary vascular remodeling. In lungs from wild-type mice (WT), exposure to hypoxia (FiO 2 = 0.1) for 21 days decreased the expression of the sEH by 70% (RT-PCR), and increased the number of partially and fully muscularised resistance arteries (by 3-fold). In isolated lungs, pre-exposure to chronic hypoxia significantly increased baseline perfusion pressures (1.3-fold) and potentiated the acute HPV (1.5-fold). While an sEH inhibitor (1-adamantyl-3-cyclohexylurea; ACU) potentiated acute HPV in lungs from mice maintained in normoxic conditions, it had no effect on HPV in lungs from mice exposed to hypoxia. The EET antagonist, 14,15-EEZE, abolished the sEH inhibitor-dependent increase in acute HPV in normoxic lungs. Under normoxic conditions the muscularization of small pulmonary arteries was greater in lungs from sEH −/− mice than in lungs from WT mice and chronic hypoxia further increased the number of fully and partially muscularized arteries in these animals. sEH −/− mice also displayed an enhanced acute HPV (1.5-fold), compared to that observed in WT mice and chronic exposure to hypoxia did not further potentiate acute HPV. Taken together, these data indicate that the sEH is involved in hypoxia-induced pulmonary vascular remodeling and hypoxic pulmonary vasoconstriction.


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