Fig. 1.

RA-induced increase in integrin α₁β₁ expression in SH-SY5Y human neuroblastoma cells. The surface expression of integrin subunits on SH-SY5Y cells was assessed by flow cytometry. Cells were grown on coverslips in DMEM plus 10% FCS and treated with RA (10 μm; b, d, f) or without RA (a, c, e) for 7 d. Cells were analyzed as described in Materials and Methods. Fluorescence intensity corresponds to the integrin α₁β₁ expression levels. a, b, Anti-mouse IgG alone; c, d, integrin anti-α₁ antibody (Ab) FB12; e, f, integrin anti-β₁ antibody P4G11.