scholarly journals Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin

Abstract When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.

Blood ◽  
1983 ◽  
Vol 62 (3) ◽  
pp. 549-556 ◽  
Author(s):  
M Laposata ◽  
DK Dovnarsky ◽  
HS Shin

When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.


2020 ◽  
pp. neurintsurg-2020-016859
Author(s):  
Alyssa McCulloch ◽  
Ashley Turcott ◽  
Gabriella Graham ◽  
Sergey Frenklakh ◽  
Kristen O'Halloran Cardinal

ObjectiveThe goal of this work was to endothelialize silicone aneurysm tubes for use as in vitro models for evaluating endothelial cell interactions with neurovascular devices. The first objective was to establish consistent and confluent endothelial cell linings and to evaluate the silicone vessels over time. The second objective was to use these silicone vessels for flow diverter implantation and assessment.MethodsSilicone aneurysm tubes were coated with fibronectin and placed into individual bioreactor systems. Human umbilical vein endothelial cells were deposited within tubes to create silicone vessels, then cultivated on a peristaltic pump and harvested at 2, 5, 7, or 10 days to evaluate the endothelial cell lining. A subset of silicone aneurysm vessels was used for flow diverter implantation, and evaluated for cell coverage over device struts at 3 or 7 days after deployment.ResultsSilicone vessels maintained confluent, PECAM-1 (platelet endothelial cell adhesion molecule 1) positive endothelial cell linings over time. These vessels facilitated and withstood flow diverter implantation, with robust cell linings disclosed after device deployment. Additionally, the endothelial cells responded to implanted devices through coverage of the flow diverter struts with increased cell coverage over the aneurysm seen at 7 days after deployment as compared with 3 days.ConclusionsSilicone aneurysm models can be endothelialized and successfully maintained in vitro over time. Furthermore, these silicone vessels can be used for flow diverter implantation and assessment.


1981 ◽  
Author(s):  
K M Spiegel ◽  
S F Mohammad ◽  
H Y K Chuang ◽  
R G Mason

Human umbilical vein endothelial cells were grown on several artificial matrices including collagen and on unmodified plastic dishes. Freeze thaw preparations of confluent monolayer endothelial cell cultures were assayed for PGI2-like activity by testing for inhibition of platelet a88regation. The cells grown on a collagen matrix expressed slightly less PGI2-like activity initially compared to the cells grown on plastic. When the PGI2like activity of the cell lysates was examined over a period of three hours after the initial preparation, endothelial cells grown on a collagen matrix exhibited a more rapid loss of activity. Preliminary quantitative evaluations suggest that lysates derived from cells grown on unmodified plastic retained 75% PGI2 like activity at 15 min, at which point collagen grown cells exhibited essentially no PGI2-like activity. Furthermore, as shown in the figure, under identical experimental conditions, cell lysates obtained from endothelial cells grown on unmodified plastic continued to express approximately 50% of the initial PGI2-like activity after one hour. Since addition of purified PGI2 or cell lysates in vitro to the collagen coating used as tissue culture substrate failed to cause any significant loss of platelet aggregation inhibitory activity beyond the normal rate of decay of PGI2 it appears likely that the reduction of PGI2-like activity may be associated with changes in the substrate collagen, possibly effected by the endothelial cell layer. Alternatively, the reduction of activity may be related to differences in the endothelial cells caused by growth on the collagen substrate.


2021 ◽  
Author(s):  
Shih-Ya Tseng ◽  
Hsien-Yuan Chang ◽  
Yi-Heng Li ◽  
Ting-Hsing Chao

Abstract Background: Cilostazol is an antiplatelet agent with vasodilating effects that functions by increasing the intracellular concentration of cyclic adenosine monophosphate. However, the effect of cilostazol on adiponectin is still unclear. Purpose: We investigated the effects of cilostazol on adiponectin/adiponectin receptors and the Sirtuin 1 (SIRT1)/AMP-activated protein kinase (AMPK) signaling pathway to prevent high glucose (HG)-induced impairment of angiogenesis in vitro and in vivo. Methods and Results: Human umbilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs) were cocultured in HG conditions. Adiponectin concentrations in the supernatant were significantly increased when HASMCs were treated with cilostazol but not significantly changed when only HUVECs were treated with cilostazol. Cilostazol treatment restored the expression of the adipoR1 and SIRT1 proteins and upregulated the phosphorylation of AMPKa1 in the HUVECs treated with HG but not adipoR2. Cilostazol prevented apoptosis and stimulated proliferation, chemotactic motility and capillary-like tube formation in HG-treated HUVECs through the adipoR1/AMPK/SIRT1 signaling pathway. In cilostazol-treated mice, recovery of the blood flow ratio after hindlimb ischemia and circulating CD34+CD45dim cells were significantly attenuated by adipoR1 knockdown but not adipoR2 knockdown. The expression of SIRT1, phosphorylation of AMPKa1/acetyl-CoA carboxylase and Akt/endothelial nitric oxide synthase in ischemic muscles were significantly attenuated by gene knockdown of adipoR1. Conclusions: Cilostazol prevents HG-induced endothelial dysfunction in vascular endothelial cells and enhances angiogenesis in hyperglycemic mice by upregulating the expression of adiponectin/adipoR1 and its SIRT1/AMPK downstream signaling pathway.


Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3445-3454 ◽  
Author(s):  
Annamaria B. Manodori ◽  
Neil M. Matsui ◽  
James Y. Chen ◽  
Stephen H. Embury

Abstract The adherence of sickle erythrocytes to vascular endothelium has the capacity to initiate vasoocclusion. The known effects of thrombin on endothelial cell function and the increased activity of thrombin in sickle cell disease led us to examine the effect of thrombin on the adhesivity of cultured endothelial cells for sickle erythrocytes. In particular, we studied whether the effect of thrombin on interendothelial cell gap formation (ICGF) was involved in endothelial cell adhesivity for sickle erythrocytes. Those endothelial cell monolayers stimulated by thrombin to maximal levels of static sickle erythrocyte adherence also underwent striking cell contraction and enlargement of interendothelial cell gaps. Adhesivity also increased when gaps were induced with antilaminin antibodies or EDTA. Maximally adhesogenic thrombin conditions failed to increase adhesivity when gap formation was prevented by pretreatment of the monolayers with 8-bromo-cyclic adenosine monophosphate (bromo-cAMP) or glutaraldehyde, agents that respectively inhibit actin-myosin–dependent cell contraction or cross-link adjacent cells in the monolayer. The influence of these two agents on EDTA-enhanced adhesivity was linked to their ability to prevent gap formation. Glutaraldehyde prevented both increased adherence and gap formation; bromo-cAMP prevented neither. Interendothelial cell gap formation may contribute to vasoocclusion by facilitating sickle erythrocyte adherence. © 1998 by The American Society of Hematology.


RSC Advances ◽  
2015 ◽  
Vol 5 (54) ◽  
pp. 43552-43562 ◽  
Author(s):  
Satish N. Nadig ◽  
Suraj K. Dixit ◽  
Natalie Levey ◽  
Scott Esckilsen ◽  
Kayla Miller ◽  
...  

Targeted micelles containing rapamycin (TRaM) suppressed the immune response of IL-8 in oxidatively stressed human umbilical vein endothelial cellsin vitro(a) and accumulated in aorta grafts for transplantation after 6 hours in cold perfusion solution (b).


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