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

Abstract

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.

Advances in microfluidic in vitro systems for neurological disease modeling

“…NVU disruption is a key feature in the pathogenesis of stroke and as microfluidic models of the NVU improve, their application to stroke research may also provide an invaluable tool in dissecting human NVU pathobiology. Vascularized microfluidic systems have already been utilized to study thrombosis, thrombolysis, endothelial inflammatory activation in embolic occlusion (Nemcovsky Amar et al., 2019), and leukocyte recruitment in arteriosclerosis under defined shear rates (Costa et al., 2017; Herbig et al., 2018; Loyau et al., 2018; Venugopal Menon et al., 2018). Application of such techniques in human NVU models could provide a powerful investigational tool in studying disruption of neurovascular coupling and the development of new therapeutic strategies for stroke.…”

Biomimetic microsystems for cardiovascular studies

“…OOC models can be designed to incorporate vascular disease features such as stenosis and pathological flow conditions (183). A HUVEC-based vascular occlusion model was used to investigate ischemic-reperfusion (184). Ischemia was simulated by engineering a clot derived from human blood to occlude the engineered vessel.…”

“…Ischemia led to an increase in E-selectin and I-CAM1, suggesting that ECs are activated under low-oxygen conditions. Upon reperfusion, cell detachment was observed suggesting that cellular damage within the system resulted from ischemic-reperfusion injury (184). Blood outgrowth endothelial cells (BOECs) were utilized to investigate vascular inflammation and thrombosis in a vascular OOC model.…”

Editorial for the Special Issue on Organs-on-Chips

“…Since the cost of drug discovery is constantly increasing due to the limited predictability of conventional monolayer culture methods and animal models, this technology has great potential to promote drug discovery and development as well as to model human physiology and disease.This Special Issue is themed to provide insight and advancements in organ-on-chip microdevices. There are fifteen papers including three review papers, covering a novel material to fabricate microfluidic organs-on-chips [1], methods to deliver mechanical stimuli [2,3], methods to measure mechanical forces [4,5], methods to evaluate cellular functions in 3D cultures [6][7][8], and specific organ models; lung chips [3,9], liver chips [10,11], blood vessel chips [12][13][14][15] including models of the outer blood-retina barrier [14] and ischemia-reperfusion injury [15].Inside the body, cells are exposed to biomechanical forces, including fluidic shear stress and mechanical strain, which regulate cell function and contribute to disease. Kaarj et al reviewed methods to produce mechanical stimuli focusing on the technical details of devices [2].…”

“…By integrating platinum electrodes into the device, this system allows to measure trans-epithelial electrical resistance (TEER) in real time, enabling to assess the epithelial barrier integrity on-chip. Nemcovsky et al developed a novel microfluidic system to model ischemia-reperfusion injury [15]. This system consists of a vascular compartment lined with human endothelial cells that can be obstructed with a human blood clot and then re-perfused by thrombolytic treatment.…”