Spermine promotes pulmonary vascular remodelling and its synthase is a therapeutic target for pulmonary arterial hypertension

2020 ◽  
Vol 56 (5) ◽  
pp. 2000522 ◽  
Author(s):  
Yang-Yang He ◽  
Yi Yan ◽  
Xin Jiang ◽  
Jun-Han Zhao ◽  
Zhe Wang ◽  
...  

Pathological mechanisms of pulmonary arterial hypertension (PAH) remain largely unexplored. Effective treatment of PAH remains a challenge. The aim of this study was to discover the underlying mechanism of PAH through functional metabolomics and to help develop new strategies for prevention and treatment of PAH.Metabolomic profiling of plasma in patients with idiopathic PAH was evaluated through high-performance liquid chromatography mass spectrometry, with spermine identified to be the most significant and validated in another independent cohort. The roles of spermine and spermine synthase were examined in pulmonary arterial smooth muscle cells (PASMCs) and rodent models of pulmonary hypertension.Using targeted metabolomics, plasma spermine levels were found to be higher in patients with idiopathic PAH compared to healthy controls. Spermine administration promoted proliferation and migration of PASMCs and exacerbated vascular remodelling in rodent models of pulmonary hypertension. The spermine-mediated deteriorative effect can be attributed to a corresponding upregulation of its synthase in the pathological process. Inhibition of spermine synthase in vitro suppressed platelet-derived growth factor-BB-mediated proliferation of PASMCs, and in vivo attenuated monocrotaline-mediated pulmonary hypertension in rats.Plasma spermine promotes pulmonary vascular remodelling. Inhibiting spermine synthesis could be a therapeutic strategy for PAH.

2020 ◽  
Vol 10 (2) ◽  
pp. 204589402092281 ◽  
Author(s):  
Kathryn S. Wilson ◽  
Hanna Buist ◽  
Kornelija Suveizdyte ◽  
John T. Liles ◽  
Grant R. Budas ◽  
...  

Pulmonary arterial hypertension, group 1 of the pulmonary hypertension disease family, involves pulmonary vascular remodelling, right ventricular dysfunction and cardiac failure. Oxidative stress, through activation of mitogen-activated protein kinases is implicated in these changes. Inhibition of apoptosis signal-regulating kinase 1, an apical mitogen-activated protein kinase, prevented pulmonary arterial hypertension developing in rodent models. Here, we investigate apoptosis signal-regulating kinase 1 in pulmonary arterial hypertension by examining the impact that its inhibition has on the molecular and cellular signalling in established disease. Apoptosis signal-regulating kinase 1 inhibition was investigated in in vivo pulmonary arterial hypertension and in vitro pulmonary hypertension models. In the in vivo model, male Sprague Dawley rats received a single subcutaneous injection of Sugen SU5416 (20 mg/kg) prior to two weeks of hypobaric hypoxia (380 mmHg) followed by three weeks normoxia (Sugen/hypoxic), then animals were either maintained for three weeks on control chow or one containing apoptosis signal-regulating kinase 1 inhibitor (100 mg/kg/day). Cardiovascular measurements were carried out. In the in vitro model, primary cultures of rat pulmonary artery fibroblasts and rat pulmonary artery smooth muscle cells were maintained in hypoxia (5% O2) and investigated for proliferation, migration and molecular signalling in the presence or absence of apoptosis signal-regulating kinase 1 inhibitor. Sugen/hypoxic animals displayed significant pulmonary arterial hypertension compared to normoxic controls at eight weeks. Apoptosis signal-regulating kinase 1 inhibitor decreased right ventricular systolic pressure to control levels and reduced muscularised vessels in lung tissue. Apoptosis signal-regulating kinase 1 inhibition was found to prevent hypoxia-induced proliferation, migration and cytokine release in rat pulmonary artery fibroblasts and also prevented rat pulmonary artery fibroblast-induced rat pulmonary artery smooth muscle cell migration and proliferation. Apoptosis signal-regulating kinase 1 inhibition reversed pulmonary arterial hypertension in the Sugen/hypoxic rat model. These effects may be a result of intrinsic changes in the signalling of adventitial fibroblast.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Gopinath Sutendra ◽  
Sebastien Bonnet ◽  
Paulette Wright ◽  
Peter Dromparis ◽  
Alois Haromy ◽  
...  

Nogo was first identified as an inhibitor of neuronal axonal regeneration. Recently, Nogo-B was implicated in the proliferative and anti-apoptotic remodeling in systemic arteries; reduced Nogo-B expression was seen in remodeled mouse femoral arteries following injury. Pulmonary arterial hypertension (PAH) is also characterized by proliferative/anti-apoptotic remodeling in pulmonary arteries (PA), sparing systemic vessels. PAH PA smooth muscle cells (PASMC) are characterized by mitochondrial hyperpolarization (increased ΔΨm), decreased production of reactive oxygen species (ROS) (suppressing mitochondria-dependent apoptosis), down-regulation of Kv1.5 and activation of the transcription factor NFAT (promoting contraction and proliferation). We found that in contrast to systemic vessels, Nogo-B expression is significantly increased in vivo and in vitro in PAs and PASMCs from patients (n=6) and mice (n=42) with PAH, compared to normals. We hypothesized that Nogo is involved in the pathogenesis of PAH . Nogo −/− mice (n=7) had a normal phenotype and, in contrast to Nogo +/+ , did not develop chronic hypoxia (CH)-induced PAH assessed invasively (catheterization, RV/LV+Septum) and non-invasively (pulmonary artery acceleration time and treadmill performance) (n=7, Table ). CH- Nogo +/+ PASMC had the expected increase in ΔΨm (measured by TMRM), decreased ROS (MitoSOX), increased [Ca ++ ] i (FLUO3), decreased Kv1.5 (immunohistochemistry) and NFAT activation (nuclear translocation). None of these changes occurred in CH- Nogo −/− PASMC while all were induced in normoxic Nogo +/+ PASMC by adenoviral over-expression of Nogo-B . Heterozygote CH- Nogo +/− (n=7) values were between Nogo −/− and Nogo +/+ suggesting a gene dose-dependent effect. Nogo is over-expressed in human and rodent PAH and induces critical features of the PAH phenotype. Nogo targeting might represent a novel and selective therapeutic strategy for PAH. Table


2019 ◽  
Vol 32 (11) ◽  
pp. 1109-1117
Author(s):  
Jun-Han Zhao ◽  
Yang-Yang He ◽  
Shan-Shan Guo ◽  
Yi Yan ◽  
Zhe Wang ◽  
...  

Abstract BACKGROUND Pulmonary arterial hypertension (PAH) is a severe progressive disease with systemic metabolic dysregulation. Monocrotaline (MCT)-induced and hypoxia-induced pulmonary hypertension (PH) rodent models are the most widely used preclinical models, however, whether or not these preclinical models recapitulate metabolomic profiles of PAH patients remain unclear. METHODS In this study, a targeted metabolomics panel of 126 small molecule metabolites was conducted. We applied it to the plasma of the 2 preclinical rodent models of PH and 30 idiopathic pulmonary arterial hypertension (IPAH) patients as well as 30 healthy controls to comparatively assess the metabolomic profiles of PAH patients and rodent models. RESULTS Significantly different metabolomics profiling and pathways were shown among the 2 classical rodent models and IPAH patients. Pathway analysis demonstrated that methionine metabolism and urea cycle metabolism were the most significant pathway involved in the pathogenesis of hypoxia-induced PH model and MCT-induced model, respectively, and both of them were also observed in the dysregulated pathways in IPAH patients. CONCLUSIONS These 2 models may develop PAH through different metabolomic pathways and each of the 2 classical PH model resembles IPAH patients in certain aspects.


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.


2015 ◽  
Vol 308 (10) ◽  
pp. L1046-L1057 ◽  
Author(s):  
Mikko H. Helenius ◽  
Sanna Vattulainen ◽  
Mark Orcholski ◽  
Joonas Aho ◽  
Anne Komulainen ◽  
...  

Endothelial cell (EC) dysfunction plays a role in the pathobiology of occlusive vasculopathy in pulmonary arterial hypertension (PAH). Purinergic signaling pathways, which consist of extracellular nucleotide and nucleoside-mediated cell signaling through specific receptors, are known to be important regulators of vascular tone and remodeling. Therefore, we hypothesized that abnormalities in the vascular purinergic microenvironment are associated with PAH. Enzymatic clearance is crucial to terminate unnecessary cell activation; one of the most abundantly expressed enzymes on the EC surface is E-NTPDase1/CD39, which hydrolyzes ATP and ADP to AMP. we used histological samples from patients and healthy donors, radioisotope-labeled substrates to measure ectoenzyme activity, and a variety of in vitro approaches to study the role of CD39 in PAH. Immunohistochemistry on human idiopathic PAH (IPAH) patients' lungs demonstrated that CD39 was significantly downregulated in the endothelium of diseased small arteries. Similarly, CD39 expression and activity were decreased in cultured pulmonary ECs from IPAH patients. Suppression of CD39 in vitro resulted in EC phenotypic switch that gave rise to apoptosis-resistant pulmonary arterial endothelial cells and promoted a microenvironment that induced vascular smooth muscle cell migration. we also identified that the ATP receptor P2Y11 is essential for ATP-mediated EC survival. Furthermore, we report that apelin, a known regulator of pulmonary vascular homeostasis, can potentiate the activity of CD39 both in vitro and in vivo. we conclude that sustained attenuation of CD39 activity through ATP accumulation is tightly linked to vascular dysfunction and remodeling in PAH and could represent a novel target for therapy.


2018 ◽  
Vol 8 (2) ◽  
pp. 204589401876829 ◽  
Author(s):  
Sasiharan Sithamparanathan ◽  
Mariana C. Rocha ◽  
Jehill D. Parikh ◽  
Karolina A. Rygiel ◽  
Gavin Falkous ◽  
...  

Mitochondrial dysfunction within the pulmonary vessels has been shown to contribute to the pathology of idiopathic pulmonary arterial hypertension (IPAH). We investigated the hypothesis of whether impaired exercise capacity observed in IPAH patients is in part due to primary mitochondrial oxidative phosphorylation (OXPHOS) dysfunction in skeletal muscle. This could lead to potentially new avenues of treatment beyond targeting the pulmonary vessels. Nine clinically stable participants with IPAH underwent cardiopulmonary exercise testing, in vivo and in vitro assessment of mitochondrial function by 31P-magnetic resonance spectroscopy (31P-MRS) and laboratory muscle biopsy analysis. 31P-MRS showed abnormal skeletal muscle bioenergetics with prolonged recovery times of phosphocreatine and abnormal muscle pH handling. Histochemistry and quadruple immunofluorescence performed on muscle biopsies showed normal function and subunit protein abundance of the complexes within the OXPHOS system. Our findings suggest that there is no primary mitochondrial OXPHOS dysfunction but raises the possibility of impaired oxygen delivery to the mitochondria affecting skeletal muscle bioenergetics during exercise.


2020 ◽  
Vol 34 (10) ◽  
pp. 2730-2744
Author(s):  
Zhi Chang ◽  
Jia‐ling Wang ◽  
Zhi‐cheng Jing ◽  
Ping Ma ◽  
Qing‐bing Xu ◽  
...  

2016 ◽  
Vol 310 (11) ◽  
pp. L1233-L1242 ◽  
Author(s):  
Jia-Xin Ye ◽  
Shan-Shan Wang ◽  
Min Ge ◽  
Dong-Jin Wang

Endothelial dysfunction plays a principal role in the pathogenesis of pulmonary arterial hypertension (PAH), which is a fatal disease with limited effective clinical treatments. Mitochondrial dysregulation and oxidative stress are involved in endothelial dysfunction. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a key regulator of cellular energy metabolism and a master regulator of mitochondrial biogenesis. However, the roles of PGC-1α in hypoxia-induced endothelial dysfunction are not completely understood. We hypothesized that hypoxia reduces PGC-1α expression and leads to endothelial dysfunction in hypoxia-induced PAH. We confirmed that hypoxia has a negative impact on endothelial PGC-1α in experimental PAH in vitro and in vivo. Hypoxia-induced PGC-1α inhibited the oxidative metabolism and mitochondrial function, whereas sustained PGC-1α decreased reactive oxygen species (ROS) formation, mitochondrial swelling, and NF-κB activation and increased ATP formation and endothelial nitric oxide synthase (eNOS) phosphorylation. Furthermore, hypoxia-induced changes in the mean pulmonary arterial pressure and right heart hypertrophy were nearly normal after intervention. These results suggest that PGC-1α is associated with endothelial function in hypoxia-induced PAH and that improved endothelial function is associated with improved cellular mitochondrial respiration, reduced inflammation and oxygen stress, and increased PGC-1α expression. Taken together, these findings indicate that PGC-1α may be a new therapeutic target in PAH.


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