scholarly journals Endothelial Cell Activation in an Embolic Ischemia-Reperfusion Injury Microfluidic Model

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 857 ◽  
Author(s):  
Danielle Nemcovsky Amar ◽  
Mark Epshtein ◽  
Netanel Korin

Ischemia, lack of blood supply, is associated with a variety of life-threatening cardiovascular diseases, including acute ischemic stroke and myocardial infraction. While blood flow restoration is critical to prevent further damage, paradoxically, rapid reperfusion can increase tissue damage. A variety of animal models have been developed to investigate ischemia/reperfusion injury (IRI), however they do not fully recapitulate human physiology of IRI. Here, we present a microfluidic IRI model utilizing a vascular compartment comprising human endothelial cells, which can be obstructed via a human blood clot and then re-perfused via thrombolytic treatment. Using our model, a significant increase in the expression of the endothelial cell inflammatory surface receptors E-selectin and I-CAM1 was observed in response to embolic occlusion. Following the demonstration of clot lysis and reperfusion via treatment using a thrombolytic agent, a significant decrease in the number of adherent endothelial cells and an increase in I-CAM1 levels compared to embolic occluded models, where reperfusion was not established, was observed. Altogether, the presented model can be applied to allow better understanding of human embolic based IRI and potentially serve as a platform for the development of improved and new therapeutic approaches.

2018 ◽  
Vol 68 (6) ◽  
pp. 209S-221S.e2 ◽  
Author(s):  
Shengye Zhang ◽  
Jane Shaw-Boden ◽  
Yara Banz ◽  
Anjan K. Bongoni ◽  
Adriano Taddeo ◽  
...  

Circulation ◽  
2020 ◽  
Vol 141 (6) ◽  
pp. 464-478 ◽  
Author(s):  
Lufang Liu ◽  
Caodi Fang ◽  
Whitney Fu ◽  
Bo Jiang ◽  
Guangxin Li ◽  
...  

Background: Ischemia reperfusion injury (IRI) predisposes to the formation of donor-specific antibodies, a factor contributing to chronic rejection and late allograft loss. Methods: We describe a mechanism underlying the correlative association between IRI and donor-specific antibodies by using humanized models and patient specimens. Results: IRI induces immunoglobulin M–dependent complement activation on endothelial cells that assembles an NLRP3 (NOD-like receptor pyrin domain-containing protein 3) inflammasome via a Rab5-ZFYVE21-NIK axis and upregulates ICOS-L (inducible costimulator ligand) and PD-L2 (programmed death ligand 2). Endothelial cell–derived interleukin-18 (IL-18) selectively expands a T-cell population (CD4+CD45RO+PD-1 hi ICOS+CCR2+CXCR5–) displaying features of recently described T peripheral helper cells. This population highly expressed IL-18R1 and promoted donor-specific antibodies in response to IL-18 in vivo. In patients with delayed graft function, a clinical manifestation of IRI, these cells were Ki-67+IL-18R1+ and could be expanded ex vivo in response to IL-18. Conclusions: IRI promotes elaboration of IL-18 from endothelial cells to selectively expand alloreactive IL-18R1+ T peripheral helper cells in allograft tissues to promote donor-specific antibody formation.


2020 ◽  
Vol 9 (19) ◽  
Author(s):  
Huijing Xia ◽  
Zhen Li ◽  
Thomas E. Sharp ◽  
David J. Polhemus ◽  
Jean Carnal ◽  
...  

Background Hydrogen sulfide (H 2 S) is an important endogenous physiological signaling molecule and exerts protective properties in the cardiovascular system. Cystathionine γ‐lyase (CSE), 1 of 3 H 2 S producing enzyme, is predominantly localized in the vascular endothelium. However, the regulation of CSE in vascular endothelium remains incompletely understood. Methods and Results We generated inducible endothelial cell‐specific CSE overexpressed transgenic mice (EC‐CSE Tg) and endothelial cell‐specific CSE knockout mice (EC‐CSE KO), and investigated vascular function in isolated thoracic aorta, treadmill exercise capacity, and myocardial injury following ischemia‐reperfusion in these mice. Overexpression of CSE in endothelial cells resulted in increased circulating and myocardial H 2 S and NO, augmented endothelial‐dependent vasorelaxation response in thoracic aorta, improved exercise capacity, and reduced myocardial‐reperfusion injury. In contrast, genetic deletion of CSE in endothelial cells led to decreased circulating H 2 S and cardiac NO production, impaired endothelial dependent vasorelaxation response and reduced exercise capacity. However, myocardial‐reperfusion injury was not affected by genetic deletion of endothelial cell CSE. Conclusions CSE‐derived H 2 S production in endothelial cells is critical in maintaining endothelial function, exercise capacity, and protecting against myocardial ischemia/reperfusion injury. Our data suggest that the endothelial NO synthase—NO pathway is likely involved in the beneficial effects of overexpression of CSE in the endothelium.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lars Hållström ◽  
Claes Frostell ◽  
Anders Herrlin ◽  
Eva Lindroos ◽  
Ingrid Lundberg ◽  
...  

Nitric oxide donors and inhaled nitric oxide (iNO) may decrease ischemia/reperfusion injury as reported in animal and human models. We investigated whether the attenuation of reperfusion injury, seen by others, in patients undergoing knee arthroplasty could be reproduced when patients had spinal anesthesia. 45 consecutive patients were randomized into three groups (n=15). Groups 1 and 3 were receiving iNO 80 ppm or placebo (nitrogen, N2) throughout the entire operation, and group 2 only received iNO in the beginning and at the end of the operation. Blood samples were collected before surgery, at the end of the surgery, and 2 hours postoperatively. Muscle biopsies were taken from quadriceps femoris muscle before and after ischemia. There were no increases in plasma levels of soluble adhesion molecules: ICAM, VCAM, P-selectin, E-selectin, or of HMGB1, in any of the groups. There were low numbers of CD68+ macrophages and of endothelial cells expression of ICAM, VCAM, and P-selectin in the muscle analyzed by immunohistochemistry, prior to and after ischemia. No signs of endothelial cell activation or inflammatory response neither systemically nor locally could be detected. The absence of inflammatory response questions this model of ischemia/reperfusion, but may also be related to the choice of anesthetic method EudraCTnr.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Elisa Zicola ◽  
Elisa Arrigo ◽  
Daniele Mancardi

Endothelial cell injury and vascular function strongly correlate with cardiac function following ischemia/reperfusion injury. Several studies indicate that endothelial cells are more sensitive to ischemia/reperfusion compared to cardiomyocytes and are critical mediators of cardiac ischemia/reperfusion injury. H2S is involved in the regulation of cardiovascular system homeostasis and can act as a cytoprotectant during ischemia/reperfusion. Activation of ERK1/2 in endothelial cells after H2S stimulation exerts an enhancement of angiogenesis while its inhibition significantly decreases H2S cardioprotective effects. In this work, we investigated how H2S pretreatment for 24 hours prevents the ischemia/reperfusion injury and promotes angiogenesis on microvascular endothelial cells following an ischemia/reperfusion protocol in vitro, using a hypoxic chamber and ischemic buffer to simulate the ischemic event. H2S preconditioning positively affected cell viability and significantly increased endothelial cell migration when treated with 1 μM H2S. Furthermore, mitochondrial function was preserved when cells were preconditioned. Since ERK1/2 phosphorylation was extremely enhanced in ischemia/reperfusion condition, we inhibited ERK both directly and indirectly to verify how H2S triggers this pathway in endothelial cells. Taken together, our data suggest that H2S treatment 24 hours before the ischemic insult protects endothelial cells from ischemia/reperfusion injury and eventually decreases myocardial injury.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Steven D Funk ◽  
Arif Yurdagul ◽  
Jonette Green ◽  
Patrick Albert ◽  
Marshall McInnis ◽  
...  

Neuronal guidance molecules are increasingly implicated in inflammatory responses. Recently, our group demonstrated enhanced expression of the neuronal guidance molecule EphA2 and its ephrinA1 ligand in mouse and human atherosclerotic plaques, and elucidated a novel proinflammatory function for EphA2 perpetuating proinflammatory gene expression during endothelial cell activation. However, a direct role for Eph/ephrins in atherosclerosis has never been demonstrated. We now show that knocking out the EphA2 gene in Western diet-fed ApoE mice blunts atherosclerotic plaque location at multiple sites. This reduction in atherosclerosis is associated with decreased monocyte infiltration and diminished expression of proinflammatory genes. EphA2 reduction may affect monocyte homing through multiple mechanisms, since reducing EphA2 expression in cytokine-activated endothelial cells does not affect endothelial adhesion molecule expression or monocyte rolling but significantly decreases firm adhesion in primary human monocytes. Like endothelial cells, plaque macrophages also express EphA2, and macrophages derived from EphA2 deficient mice show diminished expression of M1 marker genes and enhanced expression of M2 marker genes compared to their ApoE counterparts. Surprisingly, EphA2 deficient mice show significantly elevated plasma cholesterol. However, this elevation does not involve increased LDL levels but instead occurs due to elevations in plasma HDL levels. Taken together, the current data suggest EphA2 inhibition results in a multifaceted protective effect on experimental atherosclerosis characterized by reduced endothelial cell activation, monocyte recruitment, and M1/M2 polarization and enhanced circulating HDL levels.


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