BACKGROUND In order to play different roles in vascular functions as a mechanosensor to blood flows and as a barrier to transvascular exchange, the endothelial surface glycocalyx (ESG) should have an organized structure. Due to the limitations of optical and electron microscopy, the ultra-structure of ESG has not been revealed until the recent development of super-resolution optical microscopy, STORM. OBJECTIVES To investigate the ESG components and their organization on bEnd3 (mouse brain microvascular endothelial cells) monolayer. METHODS ESG was immunolabeled with anti-heparan sulfate (HS), followed by an ATTO488 conjugated goat anti-mouse IgG, and with biotinylated hyaluronic acid (HA) binding protein, followed by an AF647 conjugated anti-biotin. The ESG was then imaged by the STORM. RESULTS HA is a long molecule weaving into a network which covers the endothelial luminal surface. In contrast, HS is a shorter molecule, perpendicular to the cell surface. HA and HS are partially overlapped with each other at the endothelial luminal surface. We also quantified the length, diameter, orientation, and density of HS at the top, middle and bottom regions of the endothelial surface. CONCLUSIONS Our results suggest that HS plays a major role in mechanosensing and HA plays a major role in the molecular sieve.

中文翻译：

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内皮表面糖萼（ESG）成分和超结构通过随机光学重建显微镜（STORM）揭示。

背景技术为了在血管功能中发挥不同的作用，作为对血流的机械传感器和对跨血管交换的屏障，内皮表面糖萼（ESG）应该具有组织的结构。由于光学和电子显微镜的局限性，ESG的超微结构直到超分辨率光学显微镜STORM的最新发展才被发现。目的研究ESn组分及其在bEnd3（小鼠脑微血管内皮细胞）单层上的组织。方法用抗硫酸乙酰肝素（HS），ATTO488缀合的山羊抗小鼠IgG，生物素化的透明质酸（HA）结合蛋白，AF647缀合的抗生物素，对ESG进行免疫标记。然后由STORM对ESG进行成像。结果HA是编织到覆盖内皮腔表面的网络中的长分子。相反，HS是较短的分子，垂直于细胞表面。HA和HS在内皮腔表面彼此部分重叠。我们还量化了内皮表面顶部，中部和底部区域HS的长度，直径，方向和密度。结论我们的结果表明HS在机械传感中起主要作用，而HA在分子筛中起主要作用。内皮表面的中部和底部区域。结论我们的结果表明HS在机械传感中起主要作用，而HA在分子筛中起主要作用。内皮表面的中部和底部区域。结论我们的结果表明HS在机械传感中起主要作用，而HA在分子筛中起主要作用。