scholarly journals Endothelial cell-related autophagic pathways in Sugen/hypoxia-exposed pulmonary arterial hypertensive rats

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.


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.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 5190-5190
Author(s):  
Jason M. Aliotta ◽  
Mandy Pereira ◽  
Ashley Amaral ◽  
Arina Sorokina ◽  
Sharon I Rounds ◽  
...  

Abstract Abstract 5190 Rationale: Circulating endothelial cell-derived microparticles (MP) are altered in pulmonary arterial hypertension (PAH) but whether they are biomarkers of cellular injury or participants in disease pathogenesis is unknown. We have shown that lung-derived MP induce marrow cells to express lung-specific mRNA, protein. Objectives: Determine if lung, plasma-derived MP (LMP, PMP) alter pulmonary vascular endothelial or marrow progenitor cell phenotype to induce pulmonary vascular remodeling in PAH. Methods and Main Results: LMP, PMP isolated from monocrotaline (MCT)- or vehicle-treated mice were injected into healthy mice. Right ventricular (RV) hypertrophy and pulmonary vascular remodeling were assessed by RV-to-body weight (RV/BW), blood vessel wall thickness-to-diameter (WT/D) ratios. RV/BW, WT/D ratios were elevated in MCT vs. vehicle-injected mice (1. 99+0. 09vs. 1. 04+0. 09mg/g; 0. 159+0. 002vs. 0. 062+0. 009%). MP from MCT and vehicle-treated mice were quantitatively similar; however, MCT-LMP had higher endothelial cell mRNA expression and higher expression of mRNAs of proteins known to be abnormally expressed in PAH vs. vehicle-LMP. RV/BW, WT/D ratios were higher in mice injected with MCT-MP vs. mice injected with vehicle-MP (1. 63+0. 09vs. 1. 08+0. 09mg/g; 0. 113+0. 02vs. 0. 056+0. 01%). Lineage-depleted bone marrow cells co-cultured with MCT-MP and bone marrow cells isolated from MCT-MP infused mice had higher endothelial progenitor cell gene expression vs. cells co-cultured with vehicle-MP or cells isolated from vehicle MP infused mice. Conclusions: MP from MCT-injured mice have increased expression of growth factors implicated in PAH pathogenesis and induce RV hypertrophy, pulmonary vascular remodeling in healthy mice. Circulating MP may contribute to the development of MCT-induced pulmonary hypertension by inducing a pathologic phenotype in pulmonary vascular endothelial and endothelial progenitor cells. Disclosures: No relevant conflicts of interest to declare.


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.


2020 ◽  
Vol 115 (6) ◽  
Author(s):  
Mehreen Batool ◽  
Eva M. Berghausen ◽  
Mario Zierden ◽  
Marius Vantler ◽  
Ralph T. Schermuly ◽  
...  

AbstractSix-transmembrane protein of prostate (Stamp2) protects from diabetes and atherosclerosis in mice via anti-inflammatory mechanisms. As chronic inflammation is a hallmark of pulmonary arterial hypertension (PAH), we investigated the role of Stamp2. Stamp2 expression was substantially reduced in the lung of humans with idiopathic PAH, as well as in experimental PAH. In Stamp2-deficient mice, hypoxia modestly aggravated pulmonary vascular remodeling and right ventricular pressure compared to WT. As endothelial cell (EC) and pulmonary arterial smooth muscle cell (PASMC) phenotypes drive remodeling in PAH, we explored the role of Stamp2. Knock-down of Stamp2 in human EC neither affected apoptosis, viability, nor release of IL-6. Moreover, Stamp2 deficiency in primary PASMC did not alter mitogenic or migratory properties. As Stamp2 deficiency augmented expression of inflammatory cytokines and numbers of CD68-positive cells in the lung, actions of Stamp2 in macrophages may drive vascular remodeling. Thus, PASMC responses were assessed following treatment with conditioned media of primary Stamp2−/− or WT macrophages. Stamp2−/− supernatants induced PASMC proliferation and migration stronger compared to WT. A cytokine array revealed CXCL12, MCP-1 and IL-6 as most relevant candidates. Experiments with neutralizing antibodies confirmed the role of these cytokines in driving Stamp2’s responses. In conclusion, Stamp2 deficiency aggravates pulmonary vascular remodeling via cross-talk between macrophages and PASMC. Despite a substantial pro-inflammatory response, the hemodynamic effect of Stamp2 deficiency is modest suggesting that additional mechanisms apart from inflammation are necessary to induce severe PAH.


Shock ◽  
2007 ◽  
Vol 28 (1) ◽  
pp. 4-14 ◽  
Author(s):  
Tim Lahm ◽  
Paul R. Crisostomo ◽  
Troy A. Markel ◽  
Meijing Wang ◽  
Keith D. Lillemoe ◽  
...  

2015 ◽  
Vol 35 (6) ◽  
pp. 2079-2097 ◽  
Author(s):  
Xiufeng Yu ◽  
Tingting Li ◽  
Xia Liu ◽  
Hao Yu ◽  
Zhongfei Hao ◽  
...  

Background: We have previously shown that 15-hydroxyeicosatetraenoic acid (15-HETE) plays a critical role in pulmonary hypertension (PH)-associated vascular remodeling. However, the signaling mechanisms remain unclear. The purpose of this study was to investigate the role of 15-lipoxygenase-2 (15-LO-2)/15-HETE-mitogen-activated protein kinases (MAPKs) pathway in hypoxia-induced pulmonary vascular remodeling and the underlying mechanisms. Methods: The arterial wall thickness was measured by hematoxylin and eosin (HE) staining in distal pulmonary arteries isolated from normal and PAH patient-derived lungs. The protein expression of phosphorylated extracellular signal-regulated kinase (p-ERK) and phosphorylated p38 mitogen-activated protein kinases (p-p38MAPK) were measured by Western blot in the lungs of PAH patients and hypoxia-induced rats. The apoptosis of cultured rat pulmonary arterial smooth muscle cells (PASMCs) was determined by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and Flow cytometry. The cell proliferation and cell cycle in PASMCs following hypoxia were analyzed by bromodeoxyuridine incorporation and flow cytometry, respectively. Results: Our results showed that the levels of p-ERK and p-p38MAPK were both drastically elevated in lungs from human patients and hypoxic rats. The HE staining revealed that the medial wall thickness was higher in patients with PAH than normal humans. In cultured PASMCs, Hypoxia stimulated the cell proliferation, the cell cycle progression, and subsequently promoted cell differentiation and cell migration leading to the suppressed cell apoptosis. Furthermore, MAPKs- induced cell proliferation and anti-apoptosis in PASMCs is 15-LO-2/15HETE activation-dependent. Conclusion: Our study indicates that hypoxia-induced pulmonary vascular remodeling is associated with increased levels of 15-LO-2 and 15-HETE. 15-LO-2/15-HETE stimulates the cell proliferation and anti-apoptosis in PASMCs through phosphorylation of ERK and p38MAPK, which subsequently contributing to hypoxia-induced pulmonary vascular remodeling.


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