Figure 5. Extended durations of shear stress promote mature and definitive phenotypes.

Samples were exposed to four days of either STATIC (white bars, striped or dotted) or SHEAR treatment (τ=5.0 dyne/cm²: black bars, striped or dotted). Fluorescence of both STATIC and SHEAR samples were assessed and compared to flow cytometry control samples to calculate the percentage of cells positive for differentiation markers. Assessed proteins were PECAM1 (A) and CD41 (B, LEFT). A representative histogram of NOS3 and VWF protein expression (C) is shown for an immunostaining 2° antibody-only control (filled gray), a STATIC experimental control (gray line), and a SHEAR experimental sample (black line). To detect subtle changes in protein expression, quartile analysis was used to quantify the expression of NOS3 and VWF. Following STATIC and SHEAR treatment, hematopoietic potential was assessed using a colony counting assay (B, RIGHT). Data presented are mean ± SEM (n=3-4), where significant differences between STATIC and SHEAR groups are indicated by asterisks (* p<0.05) or displayed p-value.