Fig 1: High level expression of calponin 2 in podocyte. (a) Immunofluorescence staining of adherent E11 cells cultured on collagen coated cover slip with anti-podocin antibody showed the expression of podocin. In proliferating cells (left image), podocin shows diffused distribution and more concentrated around the nucleus. In 14-day differentiated podocytes (right image), podocin forms clusters along the edges of the cells. (b) Immunofluorescence microscopic imaging of proliferating (left image) and differentiated (right image) E11 cells also detected high level expression of nephrin, further demonstrating the podocyte feature of this cell line. Nephrin showed diffused distribution in proliferating E11 cells with higher concentration around the nucleus and formed clusters after differentiation in culture for 14 days. (c) Western blot analysis of total lysate of E11 podocytes showed the expression of calponin 2 in both proliferating and differentiated cultures. Whereas as no significant difference in the expression levels of podocin relative to actin was found between proliferative and differentiated states, calponin 2 is expressed at a significantly lower level in differentiated E11 cells, which is quantified by densitometry analysis of the Western blots normalized to the level of actin in parallel SDS-gels (d). The quantification was from four repeated experiments under the same culture conditions (n = 4). *p < 0.05 in two-tailed Student’s t test. Values are means ± SD.