scholarly journals Vascular Remodeling in Pulmonary Arterial Hypertension: The Potential Involvement of Innate and Adaptive Immunity

2021 ◽  
Vol 8 ◽  
Author(s):  
Rachid Tobal ◽  
Judith Potjewijd ◽  
Vanessa P. M. van Empel ◽  
Renee Ysermans ◽  
Leon J. Schurgers ◽  
...  

Pulmonary arterial hypertension (PAH) is a severe disease with high morbidity and mortality. Current therapies are mainly focused on vasodilative agents to improve prognosis. However, recent literature has shown the important interaction between immune cells and stromal vascular cells in the pathogenic modifications of the pulmonary vasculature. The immunological pathogenesis of PAH is known as a complex interplay between immune cells and vascular stromal cells, via direct contacts and/or their production of extra-cellular/diffusible factors such as cytokines, chemokines, and growth factors. These include, the B-cell—mast-cell axis, endothelium mediated fibroblast activation and subsequent M2 macrophage polarization, anti-endothelial cell antibodies and the versatile role of IL-6 on vascular cells. This review aims to outline the major pathophysiological changes in vascular cells caused by immunological mechanisms, leading to vascular remodeling, increased pulmonary vascular resistance and eventually PAH. Considering the underlying immunological mechanisms, these mechanisms may be key to halt progression of disease.

2020 ◽  
Vol 9 (2) ◽  
pp. 443
Author(s):  
Mathews Valuparampil Varghese ◽  
Joel James ◽  
Cody A Eccles ◽  
Maki Niihori ◽  
Olga Rafikova ◽  
...  

Vascular remodeling is considered a key event in the pathogenesis of pulmonary arterial hypertension (PAH). However, mechanisms of gaining the proliferative phenotype by pulmonary vascular cells are still unresolved. Due to well-established pyruvate dehydrogenase (PDH) deficiency in PAH pathogenesis, we hypothesized that the activation of another branch of pyruvate metabolism, anaplerosis, via pyruvate carboxylase (PC) could be a key contributor to the metabolic reprogramming of the vasculature. In sugen/hypoxic PAH rats, vascular proliferation was found to be accompanied by increased activation of Akt signaling, which upregulated membrane Glut4 translocation and caused upregulation of hexokinase and pyruvate kinase-2, and an overall increase in the glycolytic flux. Decreased PDH activity and upregulation of PC shuttled more pyruvate to oxaloacetate. This results in the anaplerotic reprogramming of lung vascular cells and their subsequent proliferation. Treatment of sugen/hypoxia rats with the PC inhibitor, phenylacetic acid 20 mg/kg, starting after one week from disease induction, significantly attenuated right ventricular systolic pressure, Fulton index, and pulmonary vascular cell proliferation. PC inhibition reduced the glycolytic shift by attenuating Akt-signaling, glycolysis, and restored mitochondrial pyruvate oxidation. Our findings suggest that targeting PC mediated anaplerosis is a potential therapeutic intervention for the resolution of vascular remodeling in PAH.


Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 66
Author(s):  
Hiroki Shoji ◽  
Yoko Yoshida ◽  
Takayuki Jujo Sanada ◽  
Akira Naito ◽  
Junko Maruyama ◽  
...  

Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure and right heart failure. Selective pulmonary vasodilators have improved the prognosis of PAH; however, they are not able to reverse pulmonary vascular remodeling. Therefore, a search for new treatment agents is required. H-1337 is an isoquinoline-sulfonamide compound that inhibits multiple serine/threonine kinases, including Rho-associated protein kinase (ROCK) and mammalian target of rapamycin (mTOR). Here, we investigated the effects of H-1337 on pulmonary hypertension and remodeling in the pulmonary vasculature and right ventricle in experimental PAH induced by SU5416 and hypoxia exposure. H-1337 and H-1337M1 exerted inhibitory effects on ROCK and Akt. H-1337 inhibited the phosphorylation of myosin light chain and mTOR and suppressed the proliferation of smooth muscle cells in vitro. H-1337 treatment also suppressed the phosphorylation of myosin light chain and mTOR in the pulmonary vasculature and decreased right ventricular systolic pressure and the extent of occlusive pulmonary vascular lesions. Furthermore, H-1337 suppressed aggravation of right ventricle hypertrophy. In conclusion, our data demonstrated that inhibition of ROCK and mTOR pathways with H-1337 suppressed the progression of pulmonary vascular remodeling, pulmonary hypertension, and right ventricular remodeling.


2018 ◽  
Vol 25 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
Adriane Bello-Klein ◽  
Daniele Mancardi ◽  
Alex S. Araujo ◽  
Paulo C. Schenkel ◽  
Patrick Turck ◽  
...  

This review addresses pulmonary arterial hypertension (PAH), an incurable disease, which determines high morbidity and mortality. Definition of the disease, its characteristics, classification, and epidemiology are discussed. A difficulty in the diagnosis of PAH due to the lack of symptoms specificity is highlighted. Echocardiographic analysis and electrocardiogram of patients help in the diagnosis and in the follow up of the disease. Nevertheless, right ventricle (RV) catheterization constitutes the gold standard for diagnosing PAH. Oxidative stress and inflammation, in an interactive manner, play a major role in the development of pulmonary vascular remodeling and consequent increase of pulmonary pressure. The latter results in an increase in RV afterload, culminating with RV hypertrophy, which may progress to failure. Both clinical and experimental studies have shown increased oxidative stress and inflammation, not only in lungs and pulmonary vasculature but also in RV. The use of experimental models, such as the monocrotaline-induced PAH, has helped in the understanding of the pathophysiology of PAH, as well as in the development of new therapeutic strategies. In addition to the traditional therapeutics, the use of therapeutic interventions capable of modulating oxidative stress and inflammation may offer newer strategies in the prevention as well as management of this disease.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Heon-Woo Lee ◽  
Takaomi Adachi ◽  
Saejeong Park ◽  
Piotr Kowalski ◽  
Daniel Anderson ◽  
...  

There is emerging evidence that the aberrant pulmonary vascular remodeling that occurs in pulmonary arterial hypertension (PAH) is at least in part driven by the transformation of endothelial cells to mesenchymal cells (EndoMT), but the mechanism driving this pathobiology remains to be fully elucidated. Bone morphogenetic protein (BMP) signaling has been implicated to be involved in EndoMT in different vascular contexts, but the exact mechanism in the pulmonary vasculature remains to be defined. We describe the role of BMP receptor type 1A (BMPR1A or ALK3) as a key factor for maintenance of endothelial fate and suppression of EndoMT in the pulmonary vasculature. We found that inducible endothelial specific deletion of Bmpr1a in mice ( Bmpr1a iECKO ) resulted in spontaneous EndoMT, with significant increase in smooth muscle actin (SMA) positive cells, associated with extensive pulmonary vascular remodeling and fibrosis. Bmpr1a iECKO mice developed spontaneous pulmonary hypertension (PH) that was mediated by augmented TGF-β signaling driven by increased TGFBR2 expression, resulting in aberrant SMAD2/3 activation. Increased TGFBR2 expression in BMPR1A deficient state was secondary to increased activity of the transcription factor TCF3, whose negative inhibition by ID2 is abrogated in BMPR1A deficient state. EndoMT and PH secondary to loss of endothelial BMPR1A was effectively rescued by concurrent knockdown of TGFBR2. Overall, these studies define a mechanism of EndoMT driven by loss of endothelial BMPR1A, and demonstrate the efficacy of inhibiting EndoMT as a potential novel therapeutic strategy in PAH and other EndoMT-related vascular disorders.


Author(s):  
◽  
Eptisam lambu

Pulmonary arterial hypertension (PAH) is a rare multifactorial disease characterized by abnormal high blood pressure in the pulmonary artery, or increased pulmonary vascular resistance (PVR), caused by obstruction in the small arteries of the lung. Increased PVR is also thought to be caused by abnormal vascular remodeling, due to thickening of the pulmonary vascular wall resulting from significant hypertrophy of pulmonary arterial smooth-muscle cells (PASMCs) and increased proliferation/impaired apoptosis of pulmonary arterial endothelial cells (PAECs). Herein, we investigated the mechanisms and explored molecular pathways mediating the lung pathogenesis in two PAH rat models: Monocrotaline (MCT) and Sugen5416/Hypoxia (SuHx). We analyzed these disease models to determine where the vasculature shows the most severe PAH pathology and which model best recapitulates the human disease. We investigated the role vascular remodeling, hypoxia, cell proliferation, apoptosis, DNA damage and inflammation play in the pathogenesis of PAH. Neither model recapitulated all features of the human disease, however each model presented with some of the pathology seen in PAH patients.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 795
Author(s):  
Maria Callejo ◽  
Daniel Morales-Cano ◽  
Gema Mondejar-Parreño ◽  
Bianca Barreira ◽  
Sergio Esquivel-Ruiz ◽  
...  

Background: Vitamin D (vitD) deficiency is highly prevalent in patients with pulmonary arterial hypertension (PAH). Moreover, PAH-patients with lower levels of vitD have worse prognosis. We hypothesize that recovering optimal levels of vitD in an animal model of PAH previously depleted of vitD improves the hemodynamics, the endothelial dysfunction and the ionic remodeling. Methods: Male Wistar rats were fed a vitD-free diet for five weeks and then received a single dose of Su5416 (20 mg/Kg) and were exposed to vitD-free diet and chronic hypoxia (10% O2) for three weeks to induce PAH. Following this, vitD deficient rats with PAH were housed in room air and randomly divided into two groups: (a) continued on vitD-free diet or (b) received an oral dose of 100,000 IU/Kg of vitD plus standard diet for three weeks. Hemodynamics, pulmonary vascular remodeling, pulmonary arterial contractility, and K+ currents were analyzed. Results: Recovering optimal levels of vitD improved endothelial function, measured by an increase in the endothelium-dependent vasodilator response to acetylcholine. It also increased the activity of TASK-1 potassium channels. However, vitD supplementation did not reduce pulmonary pressure and did not ameliorate pulmonary vascular remodeling and right ventricle hypertrophy. Conclusions: Altogether, these data suggest that in animals with PAH and severe deficit of vitD, restoring vitD levels to an optimal range partially improves some pathophysiological features of PAH.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1859.1-1860
Author(s):  
Y. Zhang ◽  
N. Zhang ◽  
Y. Zhu ◽  
Q. Wang ◽  
L. Zhou

Background:Pulmonary arterial hypertension (PAH) is a fatal complication of connective tissue diseases (CTDs). Chest CT has been increasingly used in the evaluation of patients with suspected PH noninvasively but there is a paucity of studies.Objectives:Our study was aimed to investigate the cross-sectional area (CSA) of small pulmonary vessels on chest CT for the diagnosis and prognosis of CTD-PAH.Methods:This retrospective study analyzed the data of thirty-four patients with CTD-PAH who were diagnosed by right heart catheterization (RHC) and underwent chest CT between March 2011 and October 2019. We measured the percentage of total CSA of vessels<5 mm2and 5-10 mm2as a percentage of total lung area (%CSA<5and %CSA5-10) on Chest CT. Furthermore, the association of %CSA with mean pulmonary artery pressure (mPAP) was also investigated. Besides, these patients were followed up until October 2019, and Kaplan-Meier survival curves were generated for the evaluation of prognosis.Results:Patients with CTD-PAH had significantly higher %CSA5-10than CTD-nPAH (p=0.001), %CSA5-10in CTD-S-PAH and IPAH was significantly higher than CTD-LM-PAH and COPD-PH (p<0.01). There was a positive correlation between %CSA5-10and mPAP in CTD-PAH (r=0.447, p=0.008). Considering %CSA5-10above 0.38 as a threshold level, the sensitivity and specificity were found to be 0.824 and 0.706, respectively. Patients with %CSA5-10≥0.38 had a lower survival rate than those with %CSA5-10<0.38 (p=0.049).Conclusion:Quantitative parameter, %CSA5-10on Chest CT might serve a crucial differential diagnostic tool for different types of PH. %CSA5-10≥0.38 is a prognostic indicator for evaluation of CTD-PAH.References:[1]Galie N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS Guidelines for the Diagnosis and Treatment of Pulmonary Hypertension. Rev Esp Cardiol (Engl Ed). 2016;69(2):177.[2]Siddiqui I, Rajagopal S, Brucker A, et al. Clinical and Echocardiographic Predictors of Outcomes in Patients With Pulmonary Hypertension. Am J Cardiol. 2018;122(5):872-878.[3]Coste F, Dournes G, Dromer C, et al. CT evaluation of small pulmonary vessels area in patients with COPD with severe pulmonary hypertension. Thorax. 2016;71(9):830-837.[4]Freed BH, Collins JD, Francois CJ, et al. MR and CT Imaging for the Evaluation of Pulmonary Hypertension. JACC Cardiovasc Imaging. 2016;9(6):715-732.[5]Pietra GG, Capron F, Stewart S, et al. Pathologic assessment of vasculopathies in pulmonary hypertension. J Am Coll Cardiol. 2004;43(12 Suppl S):25S-32S.[6]Zanatta E, Polito P, Famoso G, et al. Pulmonary arterial hypertension in connective tissue disorders: Pathophysiology and treatment. Exp Biol Med (Maywood). 2019;244(2):120-131.[7]Rabinovitch M, Guignabert C, Humbert M, Nicolls MR. Inflammation and immunity in the pathogenesis of pulmonary arterial hypertension. Circ Res. 2014;115(1):165-175.[8]Thenappan T, Ormiston ML, Ryan JJ, Archer SL. Pulmonary arterial hypertension: pathogenesis and clinical management. BMJ. 2018;360:j5492.[9]Thompson AAR, Lawrie A. Targeting Vascular Remodeling to Treat Pulmonary Arterial Hypertension. Trends Mol Med. 2017;23(1):31-45.[10]Shimoda LA, Laurie SS. Vascular remodeling in pulmonary hypertension. J Mol Med (Berl). 2013;91(3):297-309.[11]Rabinovitch M. Molecular pathogenesis of pulmonary arterial hypertension. J Clin Invest. 2012;122(12):4306-4313.[12]Seeger W, Adir Y, Barbera JA, et al. Pulmonary hypertension in chronic lung diseases. J Am Coll Cardiol. 2013;62(25 Suppl):D109-116.Acknowledgments:Thanks to all patients involved in this retrospective study. Thanks go to every participant who participated in this study for their enduring efforts in working with participants to complete the study. Thanks to Liangmin Wei for helping us with statistics analysis.Disclosure of Interests:None declared


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