Figure 6.

(a) Illustration showing the effect of fluid flow on the endothelial surface glycocalyx (ESG). (b) Drawing representing ESG core proteins, glycoproteins and glucosaminoglycans. HA: hyaluronic acid, HS: heparan sulfate, CS: chondroitin sulfate. (c) Transcriptomic gene expression profile of ESG-related genes. Expression is shown as the relative expression (%) of the genes present in human endothelial cells co-cultured with brain pericytes in dynamic condition as compared to static condition. Testing for differential gene expression was performed using the DESeq2 R/Bioconductor package.¹⁹ Genes with a p-value < 0.05 and less than 50% or more than 200% gene expression levels were considered to be differentially expressed. Red color labels upregulation and statistically significant expression changes, blue color shows downregulation and statistically significant expression change, cream color indicates no change in the gene expression (**p < 0.01, ***p < 0.001, ****p < 0.0001). (d) Zeta potential measured by laser Doppler velocimetry (means ± SD, n = 10; unpaired t-test, * p < 0.05 compared to static condition). (e) and (f) Fluorescent intensity analysis of the images showing wheat germ agglutinin (WGA) lectin staining and chondroitin sulfate immunocytochemistry. Image analysis values are presented as means ± SD, n = 14 images/groups; unpaired t-test, **p < 0.01 compared to static condition. (g) and (h) Staining of ESG on brain endothelial cells with fluorescently labeled WGA lectin that binds to the sialic acid residues and with chondroitin sulfate immunocytochemistry. Scale bar: 20 µm.