Introduction

The pathophysiological increase in microvascular permeability plays a well-known role in the onset and progression of diseases like sepsis and atherosclerosis. However, how interactions between neutrophils and the endothelium alter vessel permeability is often debated.

Methods

In this study, we introduce a microfluidic, silicon-membrane enabled vascular mimetic (μSiM-MVM) for investigating the role of neutrophils in inflammation-associated microvascular permeability. In utilizing optically transparent silicon nanomembrane technology, we build on previous microvascular models by enabling in situ observations of neutrophil-endothelium interactions. To evaluate the effects of neutrophil transmigration on microvascular model permeability, we established and validated electrical (transendothelial electrical resistance and impedance) and small molecule permeability assays that allow for the in situ quantification of temporal changes in endothelium junctional integrity.

Results

Analysis of neutrophil-expressed β₁ integrins revealed a prominent role of neutrophil transmigration and basement membrane interactions in increased microvascular permeability. By utilizing blocking antibodies specific to the β₁ subunit, we found that the observed increase in microvascular permeability due to neutrophil transmigration is constrained when neutrophil-basement membrane interactions are blocked. Having demonstrated the value of in situ measurements of small molecule permeability, we then developed and validated a quantitative framework that can be used to interpret barrier permeability for comparisons to conventional Transwell™ values.

Conclusions

Overall, our results demonstrate the potential of the μSiM-MVM in elucidating mechanisms involved in the pathogenesis of inflammatory disease, and provide evidence for a role for neutrophils in inflammation-associated endothelial barrier disruption.

中文翻译：

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用于白细胞-内皮相互作用研究的微血管模拟物。

介绍

微血管通透性的病理生理增加在败血症和动脉粥样硬化等疾病的发病和进展中起着众所周知的作用。然而，中性粒细胞和内皮细胞之间的相互作用如何改变血管通透性经常存在争议。

方法

在这项研究中，我们介绍了一种微流体、硅膜启用的血管模拟物 (μSiM-MVM)，用于研究中性粒细胞在炎症相关微血管通透性中的作用。在利用光学透明的硅纳米膜技术时，我们通过对中性粒细胞-内皮相互作用进行原位观察来构建先前的微血管模型。为了评估中性粒细胞迁移对微血管模型通透性的影响，我们建立并验证了电（跨内皮电阻和阻抗）和小分子通透性测定，允许对内皮连接完整性的时间变化进行原位量化。

结果

对中性粒细胞表达的 β ₁整合素的分析揭示了中性粒细胞迁移和基底膜相互作用在微血管通透性增加中的重要作用。通过利用对 β ₁亚基特异的阻断抗体，我们发现当中性粒细胞-基底膜相互作用被阻断时，观察到的由于中性粒细胞迁移引起的微血管通透性增加受到限制。在证明了小分子渗透率原位测量的价值后，我们开发并验证了一个定量框架，该框架可用于解释屏障渗透率，以便与传统的 Transwell™ 值进行比较。

结论

总的来说，我们的研究结果证明了 μSiM-MVM 在阐明炎症性疾病发病机制中的潜力，并为中性粒细胞在炎症相关的内皮屏障破坏中的作用提供了证据。