Comparison of α-smooth muscle actin expression in wild type (wt) and α8 integrin-deficient (α8-/-) mesangial cells. mRNA expression analysis by real-time RT-PCR analysis (A), representative Western blot analysis with amido black (Abl) staining as loading control (B) and immunofluorescent detection of α-smooth muscle actin (C). Arrows indicate cell nuclei of cells negative for α-smooth muscle actin. D: Doublestaining of wild type mesangial cells for α-smooth muscle actin (left) and f-actin (middle panel). Detection of f-actin in α8-/- mesangial cells (right). Results are representative for at least 3 similar experiments. Data are means ± sd. * p < 0.05 vs. wt.