Substrate stiffness heterogeneities disrupt endothelial barrier integrity in a micropillar model of heterogeneous vascular stiffening.
Substrate stiffness heterogeneities disrupt endothelial barrier integrity in a micropillar model of heterogeneous vascular stiffening.
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在异质血管硬化的微柱模型中，基质硬度异质性破坏了内皮屏障的完整性。
DOI：
10.1039/c8ib00124c
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Reinhart-King,CynthiaA
中科院分区：
文献类型：
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作者：
VanderBurgh,JacobA;Hotchkiss,Halie;Potharazu,Archit;Taufalele,PaulV;Reinhart-King,CynthiaA
内膜硬化与血管通透性增加和白细胞迁移有关，这是动脉粥样硬化的标志。然而，最近的证据表明，与年龄相关的内膜硬化并不均匀，而是以内皮下基质硬度点对点异质性增加为特征，其影响却知之甚少。为了研究空间异质基质刚性对内皮单层完整性的影响，我们开发了一种微柱模型来引入基质刚性的紧密间隔、阶跃变化，并将内皮单层表型与刚性匹配、均匀刚性和柔顺的基质进行比较。我们发现，相对于均匀柔顺的基底，阶梯刚性和均匀刚性基底对单层内粘附连接的破坏是等效的。类似地，在阶梯刚性基质上培养的单层细胞表现出与刚性匹配、均匀刚性基质上的单层细胞迁移相同的白细胞迁移百分比。与更柔顺的基底相比，在单层内，在阶梯刚性和均匀刚性的基底上，粘附连接张力和粘着斑密度增加，但尺寸不增加，这表明张力升高破坏了粘附连接的完整性。白细胞迁移频率和时间、粘着斑大小和粘着斑密度在阶梯刚性基底的刚性和顺应性子区域之间没有差异。总体而言，我们的结果表明，暴露于机械异质基质的内皮单层采用与较硬基质相关的表型，表明随着年龄的增长观察到的内膜硬度的空间异质性可能会破坏内皮屏障的完整性并导致动脉粥样硬化形成。
Intimal stiffening has been linked with increased vascular permeability and leukocyte transmigration, hallmarks of atherosclerosis. However, recent evidence indicates age-related intimal stiffening is not uniform but rather characterized by increased point-to-point heterogeneity in subendothelial matrix stiffness, the impact of which is much less understood. To investigate the impact of spatially heterogeneous matrix rigidity on endothelial monolayer integrity, we develop a micropillar model to introduce closely-spaced, step-changes in substrate rigidity and compare endothelial monolayer phenotype to rigidity-matched, uniformly stiff and compliant substrates. We found equivalent disruption of adherens junctions within monolayers on step-rigidity and uniformly stiff substrates relative to uniformly compliant substrates. Similarly, monolayers cultured on step-rigidity substrates exhibited equivalent percentages of leukocyte transmigration to monolayers on rigidity-matched, uniformly stiff substrates. Adherens junction tension and focal adhesion density, but not size, increased within monolayers on step-rigidity and uniformly stiff substrates compared to more compliant substrates suggesting that elevated tension is disrupting adherens junction integrity. Leukocyte transmigration frequency and time, focal adhesion size, and focal adhesion density did not differ between stiff and compliant sub-regions of step-rigidity substrates. Overall, our results suggest that endothelial monolayers exposed to mechanically heterogeneous substrates adopt the phenotype associated with the stiffer matrix, indicating that spatial heterogeneities in intimal stiffness observed with age could disrupt endothelial barrier integrity and contribute to atherogenesis.