Figure 3

The proliferation stimulating effect of GDNF on ISCs is mediated by NCAM. (A-C) BrdU-positive ISCs in response to GDNF stimulation with cells pre-treated with non-specific IgG (A) and NCAM polyclonal antibody (B) and the quantitative comparison (C). (D-G) NCAM mRNA (D, E) and protein (F, G) levels in ISCs and TM4 cells were significantly reduced by NCAM-specific siRNA but not by the negative control siRNA when compared with control groups (1, normal culture control; 2, negative control siRNA; 3, NCAM siRNA). G3PDH and β-actin served as the loading controls for RNA and protein respectively. Expression values of NCAM mRNA (E) or protein (G) were normalized against G3PDH or β-actin signals, respectively. (H-L) BrdU-positive ISCs with negative control siRNA (H) and NCAM siRNA groups (I) stimulated with GDNF and in normal culture controls (J) and the NCAM siRNA group (K) not treated with GDNF, as well as the quantitative comparison among all groups (L). The data is presented as means ± SD from three independent experiments. Statistically significant differences (p < 0.05) among groups are indicated by * or ** (p < 0.01). Scale bar indicates 10 μm.