Mahmoud Marwa, Cancel Limary, Tarbell John M
Tarbell Lab, Department of Biomedical Engineering, The City University of New York, New York, NY, United States.
Front Cell Dev Biol. 2021 Oct 7;9:731666. doi: 10.3389/fcell.2021.731666. eCollection 2021.
The endothelial cell glycocalyx (GCX) is a mechanosensor that plays a key role in protecting against vascular diseases. We have previously shown that age/disease mediated matrix stiffness inhibits the glycocalyx glycosaminoglycan heparan sulfate and its core protein Glypican 1 in human umbilical vein endothelial cells, rat fat pad endothelial cells and in a mouse model of age-mediated stiffness. Glypican 1 inhibition resulted in enhanced endothelial cell dysfunction. Endothelial cell culture typically occurs on stiff matrices such as plastic or glass. For the study of the endothelial GCX specifically it is important to culture cells on soft matrices to preserve GCX expression. To test the generality of this statement, we hypothesized that stiff matrices inhibit GCX expression and consequently endothelial cell function in additional cell types: bovine aortic endothelial cells, mouse aortic endothelial cell and mouse brain endothelial cells. All cell types cultured on glass showed reduced GCX heparan sulfate expression compared to cells cultured on either soft polyacrylamide (PA) gels of a substrate stiffness of 2.5 kPa (mimicking the stiffness of young, healthy arteries) or on either stiff gels 10 kPa (mimicking the stiffness of old, diseased arteries). Specific cell types showed reduced expression of GCX protein Glypican 1 (4 of 5 cell types) and hyaluronic acid (2 of 5 cell types) on glass vs soft gels. Matrix stiffness affects GCX expression in endothelial cells. Therefore, the study of the endothelial glycocalyx on stiff matrices (glass/plastic) is not recommended for specific cell types.
内皮细胞糖萼（GCX）是一种机械传感器，在预防血管疾病中起关键作用。我们之前已经表明，年龄/疾病介导的基质硬度会抑制人脐静脉内皮细胞、大鼠脂肪垫内皮细胞以及年龄介导的硬度小鼠模型中的糖萼糖胺聚糖硫酸乙酰肝素及其核心蛋白磷脂酰肌醇蛋白聚糖1（Glypican 1）。Glypican 1的抑制导致内皮细胞功能增强。内皮细胞培养通常发生在如塑料或玻璃等坚硬基质上。对于专门研究内皮GCX而言，在柔软基质上培养细胞以保持GCX表达非常重要。为了验证这一说法的普遍性，我们假设坚硬基质会抑制其他细胞类型中的GCX表达，进而影响内皮细胞功能，这些细胞类型包括牛主动脉内皮细胞、小鼠主动脉内皮细胞和小鼠脑内皮细胞。与在底物硬度为2.5 kPa的柔软聚丙烯酰胺（PA）凝胶（模拟年轻、健康动脉的硬度）或10 kPa的坚硬凝胶（模拟年老、患病动脉的硬度）上培养的细胞相比，在玻璃上培养的所有细胞类型均显示GCX硫酸乙酰肝素表达降低。特定细胞类型在玻璃与柔软凝胶上相比，显示出GCX蛋白Glypican 1（5种细胞类型中的4种）和透明质酸（5种细胞类型中的2种）表达降低。基质硬度影响内皮细胞中的GCX表达。因此，对于特定细胞类型，不建议在坚硬基质（玻璃/塑料）上研究内皮糖萼。
