scholarly journals Generation of a Novel In Vitro Model to Study Endothelial Dysfunction from Atherothrombotic Specimens

Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.

1998 ◽  
Vol 79 (03) ◽  
pp. 602-608 ◽  
Author(s):  
W. G. Jerome ◽  
S. Handt ◽  
R. R. Hantgan

SummaryThe molecular and cellular mechanisms that over a period of hours render a human thrombus progressively resistant to fibrinolysis have been probed with a novel in vitro model. The kinetics of clot formation and fibrinolysis were monitored by laser light scattering with platelet-rich model thrombi contained in cylindrical flow chambers. In selected experiments, human umbilical vein endothelial cells were also cultured to confluence on the inner walls of these “glass blood vessels”. Following an “aging” period (0.5, 2 or 4 h), each thrombus was gently perfused with a bolus of plasminogen/recombinant tissue plasminogen activator to induce fibrinolysis. Platelets delayed lysis of 2 h-aged thrombi by ~70% and (non-stimulated) endothelial cells by ~30%, compared to cell-free control clots. However, even greater lytic delays (~260%) resulted when both vascular cells were present in the same 2 h-aged thrombus. In contrast, rapid lysis was consistently achieved with R298E,R299E t-PA, a genetically engineered plasminogen activator that is insensitive to inhibition by plasminogen activator inhibitor type 1. These observations suggest platelets and endothelial cells act in concert to enrich the fibrin scaffold of an aging human thrombus in plasminogen activator inhibitor. We propose that the presence of both platelets and endothelial cells may contribute to progressive thrombolytic resistance.


RSC Advances ◽  
2019 ◽  
Vol 9 (40) ◽  
pp. 22921-22930 ◽  
Author(s):  
Kongpeng Lv ◽  
Qin Ren ◽  
Xingyan Zhang ◽  
Keda Zhang ◽  
Jia Fei ◽  
...  

Pro-angiogenic activity of astilbin on endothelial cells in vitro and zebrafish in vivo.


Blood ◽  
2003 ◽  
Vol 102 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Arne Slungaard ◽  
Jose A. Fernandez ◽  
John H. Griffin ◽  
Nigel S. Key ◽  
Janel R. Long ◽  
...  

Abstract Platelet factor 4 (PF4), an abundant platelet α-granule protein, accelerates in vitro generation of activated protein C (APC) by soluble thrombin/thrombomodulin (TM) complexes up to 25-fold. To test the hypothesis that PF4 similarly stimulates endothelium-associated TM, we assessed the influence of human PF4 on thrombin-dependent APC generation by cultured endothelial monolayers. APC generated in the presence of 1 to 100 μg PF4 was up to 5-fold higher than baseline for human umbilical vein endothelial cells, 10-fold higher for microvascular endothelial cells, and unaltered for blood outgrowth endothelial cells. In an in vivo model, cynomolgus monkeys (n = 6, each serving as its own control) were infused with either PF4 (7.5 mg/kg) or vehicle buffer, then with human thrombin (1.0 μg/kg/min) for 10 minutes. Circulating APC levels (baseline 3 ng/mL) peaked at 10 minutes, when PF4-treated and vehicle-treated animals had APC levels of 67 ± 5 ng/mL and 39 ± 2 ng/mL, respectively (P < .001). The activated partial thromboplastin time (APTT; baseline, 28 seconds) increased maximally by 27 ± 6 seconds in PF4-treated animals and by 9 ± 1 seconds in control animals at 30 minutes (P < .001). PF4-dependent increases in circulating APC and APTT persisted more than 2-fold greater than that of control's from 10 through 120 minutes (P ≤ .04). All APTT prolongations were essentially reversed by monoclonal antibody C3, which blocks APC activity. Thus, physiologically relevant concentrations of PF4 stimulate thrombin-dependent APC generation both in vitro by cultured endothelial cells and in vivo in a primate thrombin infusion model. These findings suggest that PF4 may play a previously unsuspected physiologic role in enhancing APC generation. (Blood. 2003;102:146-151)


2020 ◽  
Author(s):  
Ying Jiang ◽  
Hong Zhu ◽  
Hong Chen ◽  
Meng-Meng Yang ◽  
Yi-Chen Yu ◽  
...  

Abstract Background: The cardiovascular dysfunction in children born after in vitro fertilization (IVF) has been of great concern, in our study, we aim to explore potential molecular mechanism for such long-term outcomes. Methods:Real-time qPCR was used to test long non-coding RNA MEG3 and endothelium-derived factors, endothelial nitric oxide synthase (eNOS), endothelin-1(ET1), vascular endothelial growth factor (VEGF). Primary HUVEC after caesarean section was treated with different estradiol concentrations in vitro. Besides, knockdown of MEG3 on HUVEC provided further evidence between MEG3 expression and alteration of NO, ET1, VEGF. Then, by using pyrosequencing, we detected MEG3 promoter methylation status.Results: We found that the expression level of MEG3 was higher in human umbilical vein endothelial cells (HUVECs) of IVF offspring than that in spontaneously born offspring. Furthermore, we found decreased expression of eNOS, VEGF, elevated expression of ET1 in HUVECs from IVF offspring compared to spontaneously born offspring. We further confirmed the results from in-vivo experiments by demonstrating that high-estradiol intrauterine environments lead to abnormal expression of MEG3 and endothelium-derived factors. Meanwhile, silencing MEG3 expression decreased ET1 expression, and increased nitrite, nitrate, VEGF secretion, which could correct the effect we observed in-vivo. With pyrosequencing technology, we found that elevated expression of MEG3 in IVF offspring derived HUVECs was the result of hypomethylation of the MEG3 promoter. Conclusions: Our results demonstrated that higher expression of MEG3 in IVF-born HUVECs, accompanied by lower secretion of eNOS, VEGF, and higher secretion of ET1, which is closely related with endothelial dysfunction, which together provide a potential mechanism addressing high-risk of hypertension in IVF offspring.


1994 ◽  
Vol 267 (3) ◽  
pp. H874-H879 ◽  
Author(s):  
A. Pietersma ◽  
N. De Jong ◽  
J. F. Koster ◽  
W. Sluiter

The objective of this study was to investigate the effect of hypoxia on the adhesiveness of endothelial cells for granulocytes. Human umbilical vein endothelial cells (HUVEC) were exposed to a PO2 of 7.5 mmHg (1.0 kPa), and the adherence of granulocytes was assessed under continuous hypoxia by means of a hypoxic incubator room. After 2 h of hypoxia the adherence of granulocytes decreased to 50% of the normoxic control, which was not due to a decreased viability of the endothelial cells nor to an increased generation of the antiadhesive factors nitric oxide, prostacyclin, and adenosine. Hypoxia also had no effect on the expression of intercellular adhesion molecule (ICAM)-1 or ICAM-2 on the endothelium. Although the mechanism of the action of hypoxia on the adhesiveness of endothelial cells remains unclear as yet, our data suggest that HUVEC possess a protective mechanism that prevents granulocyte adherence to endothelial cells under extreme hypoxic conditions. The decreased adherence seems paradoxical to the in vivo situation for which the increased margination of granulocytes within the vascular compartment of the ischemic tissue has been observed. However, hypoxia did not impair the potential adhesiveness of HUVEC, since stimulation of endothelial cells under hypoxic conditions with calcium ionophore or lipopolysaccharide increased the adherence of granulocytes in a similar fashion as under normoxic conditions. We therefore conclude that the increased margination of granulocytes during ischemia may be accomplished by the additional stimulation of hypoxic endothelial cells.


1990 ◽  
Vol 259 (1) ◽  
pp. G134-G139 ◽  
Author(s):  
W. Inauen ◽  
D. N. Granger ◽  
C. J. Meininger ◽  
M. E. Schelling ◽  
H. J. Granger ◽  
...  

The major objective of this study was to develop an in vitro model of ischemia/reperfusion (I/R)-induced microvascular injury. Cultured venular endothelial cells were grown to confluency, labeled with 51Cr, and exposed to different durations of anoxia (0.5, 1, 2, 3, and 4 h). 51Cr release and cell detachment (indexes of cell injury) were determined at different times after reoxygenation (1, 2, 4, 6, 8, and 18 h). Because in vivo studies have implicated neutrophils in I/R injury, in some experiments human neutrophils were added to the endothelial cells upon reoxygenation. Periods of anoxia greater than or equal to 2 h resulted in 70-80% 51Cr release and 80-95% cell detachment upon reoxygenation. Under these conditions (near maximal injury), the addition of neutrophils produced negligible effects. Periods of anoxia less than or equal to 1 h resulted in 30-40% 51Cr release and 50-60% cell detachment. Under these conditions (moderate cell injury), addition of neutrophils enhanced endothelial cell injury. Using a 30-min period of anoxia, we also assessed the effects of superoxide dismutase (SOD; 300 U/ml) and allopurinol (20 microM) on anoxia/reoxygenation (A/R)-induced injury in the presence or absence of neutrophils. In the absence of neutrophils, SOD or allopurinol did not protect against A/R-induced injury. However, in the presence of neutrophils, both SOD and allopurinol attenuated the increases in 51Cr release. The results derived using this in vitro model of I/R injury are largely consistent with published in vivo studies. Thus this in vitro model may provide further insights regarding the mechanisms involved in I/R injury.


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