scholarly journals Pulmonary hypertension after pneumonectomy: a preclinical model in rats and human pulmonary endothelial cells

2020 ◽  
Vol 59 (1) ◽  
pp. 147-154
Author(s):  
Pierre Sentenac ◽  
Gianluca Samarani ◽  
Patrice Bideaux ◽  
Pierre Sicard ◽  
Benjamin Bourdois ◽  
...  

Abstract OBJECTIVES Pulmonary hypertension and heart disease contribute to the high morbidity rate following pneumonectomy (PN). The pathophysiology is still poorly understood. The objective was to investigate the consequences of PN on cardiopulmonary function in rats and to explore in vitro the involved mechanisms. METHODS Sixty Sprague-Dawley male rats randomly underwent either a right PN (PN group) or sham surgery. Ten rats per group were sacrificed on postoperative days 3, 7 and 28. Cardiopulmonary alterations were investigated by echocardiographic, haemodynamic and histological analyses. In vitro, the shear stress was reproduced using a Flexcell Tension™ cyclic stretch on cultured human pulmonary endothelial cells (P-ECs) to investigate the impact on pulmonary artery smooth muscle cell (PA-SMC) growth. Data are expressed as mean ± SD. RESULTS Mean pulmonary arterial pressure gradually increased in the PN group to reach 35 ± 7 mmHg on postoperative day 28 vs 18 ± 4 in sham (P = 0.001), likewise the proportion of muscularized distal pulmonary arteries, 83 ± 1% vs 5 ± 1%, respectively (P < 0.001), related to in situ PA-SMC proliferation. The right ventricle area and lateral wall thickness were doubled in the PN group on postoperative day 28. The left ventricle ejection fraction decreased on postoperative days 7 and 28 while the right ventricle function was maintained. In vitro, the human PA-SMC growth was significantly greater when seeded with stretched vs non-stretched P-EC media, highlighting the role of shear stress on the P-EC paracrine function. CONCLUSIONS Right PN led to pulmonary hypertension and proportional right heart remodelling in rats. The shear stress related to high blood flow alters the pulmonary endothelial paracrine control of SMC growth.

2020 ◽  
Vol 17 (2) ◽  
pp. 98-109
Author(s):  
N.L. Kolomeyets ◽  
◽  
O.V. Syslonova ◽  
S.L. Smirnova ◽  
I.M. Roshchevskaya ◽  
...  

The aim of the work was to study the bioelectric impedance of the body in rats of both genders with monocrotaline-induced pulmonary hypertension. Materials and methods. Multi-frequency bioimpedance studies of the body of rats of both genders were carried out one month after the administration of monocrotaline (dose of 60 mg/kg, subcutaneously). Results. Hypertrophy of the right ventricle of the heart was revealed in animals with experimentally induced pulmonary hypertension, with a significantly greater thickness of the free wall of the right ventricle in males compared to females. Significant influence of the interaction of the gender factor and the effect of monocrotaline on the indicators of the bioelectric impedance of the body (amplitude, ratio of resistances at low and high current frequencies) was shown using the method of analysis of variance. The body bioelectric impedance amplitudes, normalized to body length, were significantly lower in the male rats and higher in the female rats with experimental pulmonary hypertension compared to the control animals of the same gender. In the female rats with the monocrotaline model of pulmonary hypertension, the ratio of the amplitudes of the bioelectric impedance of the body at low and high current frequencies was significantly lower than in the control animals. Conclusion. Changes in the body resistance of the rats with pulmonary hypertension indicate an inflammatory process. Gender differences in the changes in the bioelectrical impedance of the body indicate a more severe manifestation of pulmonary hypertension in the males.


Perfusion ◽  
2021 ◽  
pp. 026765912110125
Author(s):  
Alexander O Ward ◽  
Graciela B Sala-Newby ◽  
Shameem Ladak ◽  
Gianni D Angelini ◽  
Massimo Caputo ◽  
...  

Vascular endothelial cell stimulation is associated with the activation of different signalling pathways and transcription factors. Acute shear stress is known to induce different pro-inflammatory mediators such as IL-8. Nrf2 is activated by prolonged high shear stress promoting an antiinflammatory and athero-protective environment. However, little is known about the impact of acute shear stress on Nrf2 and Keap1 function and its role in IL-8 regulation. We aimed to examine Nrf2-Keap1 complex activation in-vitro and its role in regulating IL-8 transcripts under acute arterial shear stress (12 dyn/cm2) in venous endothelial cells (ECs). We note that acute high shear stress caused a significant upregulation of Nrf2 target genes, HO-1 and GCLM and an increased IL-8 upregulation at 90 and 120 minutes. Mechanistically, acute high shear did not affect Nrf2 nuclear translocation but resulted in reduced nuclear Keap1, suggesting that the reduction in nuclear Keap1 may result in increased free nuclear nrf2 to induce transcription. Consistently, the suppression of Keap1 using shRNA (shKeap1) resulted in significant upregulation of IL-8 transcripts in response to acute shear stress. Interestingly; the over expression of Nrf2 using Nrf2-Ad-WT or Sulforaphane was also associated with significant upregulation of IL-8 compared to controls. This study highlights the role of Keap1 in Nrf2 activation under shear stress and indicates that activation of Nrf2 may be deleterious in ECs in the context of acute haemodynamic injury.


Blood ◽  
2008 ◽  
Vol 112 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Thomas Korff ◽  
Jennifer Braun ◽  
Dennis Pfaff ◽  
Hellmut G. Augustin ◽  
Markus Hecker

Abstract Expression of the arterial marker molecule ephrinB2 in endothelial cells is a prerequisite for adequate remodeling processes of the developing or angiogenic vasculature. Although its role in these processes has been extensively studied, the impact of ephrinB2 on the remodeling of adult arteries is largely unknown. To this end, we analyzed its expression during a biomechanically induced arteriolar remodeling process known as arteriogenesis and noted a significant increase in ephrinB2 expression under these conditions. By examining those biomechanical forces presumed to drive arteriogenesis, we identified cyclic stretch as a critical inducer of ephrinB2 expression in endothelial cells. Subsequent functional analyses in vitro revealed that endothelial cells expressing ephrinB2 limit the migration of smooth muscle cells, thereby enhancing segregation of both cell types. Moreover, MCP-1 induced transmigration of monocytes through a monolayer of endothelial cells overexpressing a truncated variant of ephrinB2 was clearly impeded. Taken together, these data suggest that expression of ephrinB2 in adult endothelial cells is up-regulated during arterial remodeling and controlled by cyclic stretch, a well-known inducer of such processes. This stretch-induced ephrinB2 expression may be pivotal for arteriogenesis as it limits smooth muscle cell migration within defined borders and controls monocyte extravasation.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Vos ◽  
T Leiner ◽  
A.P.J Van Dijk ◽  
F.J Meijboom ◽  
G.T Sieswerda ◽  
...  

Abstract Introduction Precapillary pulmonary hypertension (pPH) causes right ventricular (RV) pressure overload inducing RV remodeling, often resulting in dysfunction and dilatation, heart failure, and ultimately death. The ability of the right ventricle to adequately adapt to increased pressure loading is key for patients' prognosis. RV ejection fraction (RVEF) by cardiac magnetic resonance (CMR) is related to outcome in pPH patients, but this global measurement is not ideal for detecting early changes in RV function. Strain analysis on CMR using feature tracking (FT) software provides a more detailed assessment, and might therefore detect early changes in RV function. Aim 1) To compare RV strain parameters in pPH patients and healthy controls, and 2) to compare strain parameters in a subgroup of pPH patients with preserved RVEF (pRVEF) and healthy controls. Methods In this prospective study, a CMR was performed in pPH patients and healthy controls. Using FT-software on standard cine images, the following RV strain parameters were analyzed: global, septal, and free wall longitudinal strain (GLS, sept-LS, free wall-LS), time to peak strain (TTP, as a % of the whole cardiac cycle), the fractional area change (FAC), global circumferential strain (GCS), global longitudinal and global circumferential strain rate (GLSR and GCSR, respectively). A pRVEF is defined as a RVEF >50%. To compare RV strain parameters in pPH patients to healthy controls, the Mann-Whitney U test was used. Results 33 pPH-patients (55 [45–63] yrs; 10 (30%) male) and 22 healthy controls (40 [36–48] yrs; 15 (68%) male) were included. All RV strain parameters were significantly reduced in pPH patients compared to healthy controls (see table), except for GCS and GCSR. Most importantly, in pPH patients with pRVEF (n=8) GLS (−26.6% [−22.6 to −27.3] vs. −28.1% [−26.2 to −30.6], p=0.04), sept-LS (−21.2% [−19.8 to −23.2] vs. −26.0% [−24.0 to −27.9], p=0.005), and FAC (39% [35–44] vs. 44% [42–47], p=0.02) were still significantly impaired compared to healthy controls. The RV TTP was significantly increased in pPH patients compared to healthy controls (47% [44–57] vs. 40% [33–43], p≤0.001). Conclusions Several CMR-FT strain parameters of the right ventricle are impaired in pPH patients when compared to healthy controls. Moreover, even in pPH patients with a preserved RVEF multiple RV strain parameters (GLS, sept-LS, and FAC) remained significantly impaired, and TTP significantly prolonged, in comparison to healthy controls. This suggests that RV strain parameters may be used as an early marker of RV dysfunction in pPH patients. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 22 (11) ◽  
pp. 5635
Author(s):  
Katharina Urschel ◽  
Miyuki Tauchi ◽  
Stephan Achenbach ◽  
Barbara Dietel

In the 1900s, researchers established animal models experimentally to induce atherosclerosis by feeding them with a cholesterol-rich diet. It is now accepted that high circulating cholesterol is one of the main causes of atherosclerosis; however, plaque localization cannot be explained solely by hyperlipidemia. A tremendous amount of studies has demonstrated that hemodynamic forces modify endothelial athero-susceptibility phenotypes. Endothelial cells possess mechanosensors on the apical surface to detect a blood stream-induced force on the vessel wall, known as “wall shear stress (WSS)”, and induce cellular and molecular responses. Investigations to elucidate the mechanisms of this process are on-going: on the one hand, hemodynamics in complex vessel systems have been described in detail, owing to the recent progress in imaging and computational techniques. On the other hand, investigations using unique in vitro chamber systems with various flow applications have enhanced the understanding of WSS-induced changes in endothelial cell function and the involvement of the glycocalyx, the apical surface layer of endothelial cells, in this process. In the clinical setting, attempts have been made to measure WSS and/or glycocalyx degradation non-invasively, for the purpose of their diagnostic utilization. An increasing body of evidence shows that WSS, as well as serum glycocalyx components, can serve as a predicting factor for atherosclerosis development and, most importantly, for the rupture of plaques in patients with high risk of coronary heart disease.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Maria Drakopoulou ◽  
Konstantinos Stathogiannis ◽  
Konstantinos Toutouzas ◽  
George Latsios ◽  
Andreas Synetos ◽  
...  

Objective: Severe aortic stenosis leads to increased pulmonary arterial systolic pressure. A controversy still remains regarding the impact of persistent pulmonary hypertension (PHT) on prognosis of patients undergoing transcatheter aortic valve implantation (TAVI). We sought to investigate the impact of persistent PHT on 2-year all-cause mortality of patients with severe aortic stenosis following TAVI. Methods: Patients with severe and symptomatic aortic stenosis (effective orifice area [EOA]≤1 cm 2 ) who were scheduled for TAVI with a self-expanding valve at our institution were prospectively enrolled. Prospectively collected echocardiographic data before and after TAVI were retrospectively analyzed in all patients. Pulmonary artery systolic pressure was estimated as the sum of the right ventricular to the right atrial gradient during systole and the right atrial pressure. PHT following TAVI was classified as absent if <35 mmHg and persistent if ≥35 mmHg. Primary clinical end-point was 2-year all-cause mortality defined according to the criteria proposed by the Valve Academic Research Consortium-2. Results: Hundred and forty patients (mean age: 82±9 years) were included in the study. The primary clinical end point occurred in 17 patients (12%) during a median follow-up period of 2 years. Mean pulmonary artery systolic pressure was reduced in all patients following TAVI (45±9 versus 41±6 mmHg, p<0.01). Mortality rate was higher in patients with persistent PHT compared to patients with normal pulmonary artery systolic pressure following TAVI (26% versus 14 %, p<0.01). Patients that reached the primary clinical end point had a higher post procedural mean systolic pulmonary pressure (43±9 versus 39±6 mmHg, p=0.02). In multivariate regression analysis, persistence of PHT (OR: 2.51, 95% CI: 1.109-7.224, p=0.01) was an independent predictor of long-term mortality. Conclusions: The persistence of pulmonary hypertension after TAVI is associated with long term mortality. Identifying the population that will clearly benefit from TAVI is still need to be validated by larger trials.


EP Europace ◽  
2017 ◽  
Vol 19 (suppl_3) ◽  
pp. iii339-iii339
Author(s):  
U. Gulan ◽  
AM. Saguner ◽  
D. Akdis ◽  
C. Brunckhorst ◽  
M. Holzner ◽  
...  

Author(s):  
Gayathri Viswanathan ◽  
Argen Mamazhakypov ◽  
Ralph T. Schermuly ◽  
Sudarshan Rajagopal

2015 ◽  
Vol 46 (3) ◽  
pp. 832-842 ◽  
Author(s):  
Emmy Manders ◽  
Silvia Rain ◽  
Harm-Jan Bogaard ◽  
M. Louis Handoko ◽  
Ger J.M. Stienen ◽  
...  

Pulmonary arterial hypertension (PAH) is a fatal lung disease characterised by progressive remodelling of the small pulmonary vessels. The daily-life activities of patients with PAH are severely limited by exertional fatigue and dyspnoea. Typically, these symptoms have been explained by right heart failure. However, an increasing number of studies reveal that the impact of the PAH reaches further than the pulmonary circulation. Striated muscles other than the right ventricle are affected in PAH, such as the left ventricle, the diaphragm and peripheral skeletal muscles. Alterations in these striated muscles are associated with exercise intolerance and reduced quality of life. In this Back to Basics article on striated muscle function in PAH, we provide insight into the pathophysiological mechanisms causing muscle dysfunction in PAH and discuss potential new therapeutic strategies to restore muscle dysfunction.


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