Fig. 2

Internalization of OL peptide in hCMEC/D3 cells. a1–a3 Concentration-dependent increase in the cellular uptake of FAM-OL peptide (green) and endosomal marker, pHRodo Red merged with DAPI (blue) versus scrambled peptide. b Cellular uptake of FAM-OL peptide and scrambled peptide at 37 °C and 4 °C as determined from the total cell lysates and normalized per µg protein. c1 Co-localization of the FAM-OL peptide with endosomal (pHRhodo Red) and c2 lysosomal markers (LysoTracker^® Red). Images captured at 40 × (scale = 100 µm) were further magnified in the insets. ****P < 0.0001 versus different concentrations of active peptide; ^##P < 0.01 scramble peptide versus scrambled peptide at different concentrations (50 vs. 100 µg/mL); ⁺⁺⁺P < 0.001 active versus scrambled peptide at 100 µg/mL concentrations; ^$P < 0.05 versus 4 °C at 100 µg/mL concentrations. All images were originally captured at 40X (N = 4–5 biological replicates/group pooled from two independent experiments were used for statistical analyses)