scholarly journals Endothelial Cell–Derived Interleukin-18 Released During Ischemia Reperfusion Injury Selectively Expands T Peripheral Helper Cells to Promote Alloantibody Production

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.

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.


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.


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.


2017 ◽  
Vol 40 (4) ◽  
pp. 1201-1209 ◽  
Author(s):  
Bing Xiao ◽  
Yi Chai ◽  
Shigang Lv ◽  
Minhua Ye ◽  
Miaojing Wu ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xutong Li ◽  
Ye Zhang ◽  
Yong Wang ◽  
Dan Zhao ◽  
Chengcheng Sun ◽  
...  

Background. Ischemic stroke is a severe acute cerebrovascular disease which can be improved with neuroprotective therapies at an early stage. However, due to the lack of effective neuroprotective drugs, most stroke patients have varying degrees of long-term disability. In the present study, we investigated the role of exosomes derived from CXCR4-overexpressing BMSCs in restoring vascular function and neural repair after ischemic cerebral infarction. Methods. BMSCs were transfected with lentivirus encoded by CXCR4 (BMSCCXCR4). Exosomes derived from BMSCCXCR4 (ExoCXCR4) were isolated and characterized by transmission electron microscopy and dynamic light scattering. Western blot and qPCR were used to analyze the expression of CXCR4 in BMSCs and exosomes. The acute middle cerebral artery occlusion (MCAO) model was prepared, ExoCXCR4 were injected into the rats, and behavioral changes were analyzed. The role of ExoCXCR4 in promoting the proliferation and tube formation for angiogenesis and protecting brain endothelial cells was determined in vitro. Results. Compared with the control groups, the ExoCXCR4 group showed a significantly lower mNSS score at 7 d, 14 d, and 21 d after ischemia/reperfusion ( P < 0.05 ). The bEnd.3 cells in the ExoCXCR4 group have stronger proliferation ability than other groups ( P < 0.05 ), while the CXCR4 inhibitor can reduce this effect. Exosomes control (ExoCon) can significantly promote the migration of bEnd.3 cells ( P < 0.05 ), while there was no significant difference between the ExoCXCR4 and ExoCon groups ( P > 0.05 ). ExoCXCR4 can further promote the proliferation and tube formation for the angiogenesis of the endothelium compared with ExoCon group ( P < 0.05 ). In addition, cobalt chloride (COCl2) can increase the expression of β-catenin and Wnt-3, while ExoCon can reduce the expression of these proteins ( P < 0.05 ). ExoCXCR4 can further attenuate the activation of Wnt-3a/β-catenin pathway ( P < 0.05 ). Conclusions. In ischemia/reperfusion injury, ExoCXCR4 promoted the proliferation and tube formation of microvascular endothelial cells and play an antiapoptotic role via the Wnt-3a/β-catenin pathway.


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