Figure 5.
α5β1 integrin internalizes SPARC-mimicking peptides. Culture of human adipose stem cells (ASC) (A–C), human prostate PC3 carcinoma cells (D), and mouse ASC (E, F) subjected to internalization of 109 TU phage displaying hPep (A, D, E), mPep (B), or control insertless phage (C, F). Washed cells were fixed and analyzed for intracellular phage detected with Cy-3 immunofluorescence (red). Peptide uptake was particularly high in clones of actively dividing small ASC populations with compact nuclei (arrows) but not in quiescent cells (arrowheads), as revealed by DNA fluorescence (blue [E, F]). Scale bar = 5 µm.