Department of Biomedical Engineering, The City College of New York, New York, NY, USA.
Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
Cardiovasc Res. 2021 May 25;117(6):1592-1605. doi: 10.1093/cvr/cvaa201.
Arterial stiffness is an underlying risk factor and a hallmark of cardiovascular diseases. The endothelial cell (EC) glycocalyx is a glycan rich surface layer that plays a key role in protecting against EC dysfunction and vascular disease. However, the mechanisms by which arterial stiffness promotes EC dysfunction and vascular disease are not fully understood, and whether the mechanism involves the protective endothelial glycocalyx is yet to be determined. We hypothesized that endothelial glycocalyx protects the endothelial cells lining the vascular wall from dysfunction and disease in response to arterial stiffness.
Cells cultured on polyacrylamide (PA) gels of substrate stiffness 10 kPa (mimicking the subendothelial stiffness of aged, unhealthy arteries) showed a significant inhibition of glycocalyx expression compared to cells cultured on softer PA gels (2.5 kPa, mimicking the subendothelial stiffness of young, healthy arteries). Specifically, gene and protein analyses revealed that a glycocalyx core protein Glypican 1 was inhibited in cells cultured on stiff PA gels. These cells had enhanced endothelial cell dysfunction as determined by enhanced cell inflammation (enhanced inflammatory gene expression, monocyte adhesion, and inhibited nitric oxide expression), proliferation, and EndMT. Removal of Glypican 1 using gene-specific silencing with siRNA or gene overexpression using a plasmid revealed that Glypican 1 is required to protect against stiffness-mediated endothelial cell dysfunction. Consistent with this, using a model of age-mediated stiffness, older mice exhibited a reduced expression of Glypican 1 and enhanced endothelial cell dysfunction compared to young mice. Glypican 1 gene deletion in knockout mice (GPC1-/-) exacerbated endothelial dysfunction in young mice, which normally had high endothelial expression, but not in old mice that normally expressed low levels. Endothelial cell dysfunction was exacerbated in young, but not aged, Glypican 1 knockout mice (GPC1-/-).
Arterial stiffness promotes EC dysfunction and vascular disease at least partly through the suppression of the glycocalyx protein Glypican 1. Glypican 1 contributes to the protection against endothelial cell dysfunction and vascular disease in endothelial cells.
动脉僵硬是心血管疾病的潜在风险因素和标志。内皮细胞 (EC) 糖萼是富含聚糖的表面层，在保护内皮细胞功能障碍和血管疾病方面发挥着关键作用。然而，动脉僵硬促进内皮细胞功能障碍和血管疾病的机制尚不完全清楚，并且该机制是否涉及保护性内皮糖萼仍有待确定。我们假设内皮糖萼可保护血管壁内皮细胞免受动脉僵硬引起的功能障碍和疾病的影响。
与在较软的聚丙稀酰胺 (PA) 凝胶（模拟年轻、健康动脉的亚内皮硬度）上培养的细胞相比，在基质硬度为 10kPa 的 PA 凝胶（模拟老化、不健康动脉的亚内皮硬度）上培养的细胞中，糖萼的表达明显受到抑制。具体而言，基因和蛋白质分析表明，在硬 PA 凝胶上培养的细胞中糖萼核心蛋白 Glypican 1 受到抑制。这些细胞的内皮细胞功能障碍增强，表现为细胞炎症增强（炎症基因表达增强、单核细胞黏附、一氧化氮表达受抑制）、增殖和 EndMT。使用基因特异性沉默的 siRNA 或使用质粒进行基因过表达去除 Glypican 1 后发现，Glypican 1 是防止僵硬介导的内皮细胞功能障碍所必需的。与此一致的是，在年龄介导的僵硬模型中，与年轻小鼠相比，老年小鼠的 Glypican 1 表达降低，内皮细胞功能障碍增强。在年轻的 Glypican 1 敲除小鼠 (GPC1-/-) 中，内皮细胞功能障碍加剧，而在正常表达高水平 Glypican 1 的年轻小鼠中则没有加剧，而在正常表达低水平 Glypican 1 的老年小鼠中也没有加剧。在年轻而非老年的 Glypican 1 敲除小鼠 (GPC1-/-) 中，内皮细胞功能障碍加剧。
动脉僵硬至少部分通过抑制糖萼蛋白 Glypican 1 来促进内皮细胞功能障碍和血管疾病。Glypican 1 有助于保护内皮细胞免受内皮细胞功能障碍和血管疾病的影响。
