Figure 5.

Effects of RNAi knock-down of APP on levels of Numb in H4-APP cells. In H4-APP cells, APP siRNA treatment decreases protein levels of Numb. A. Levels of FL-APP, APP-CTFs and Numb in Western blot analyses. APP immunoblotting shows reductions in protein levels of FL-APP, APP-CTFs in the cells treated with APP siRNA (columns 3 and 4) as compared to that treated with control siRNA (columns 1 and 2). Numb immunoblotting shows reductions in protein levels of Numb in the cells treated with Numb siRNA (columns 3 and 4) as compared to control siRNA (columns 1 and 2). B. FL-APP levels assessed by quantifying FL-APP in the Western blot. APP siRNA treatment significantly decreases protein levels of FL-APP as compared to control siRNA (**p < 0.01), normalized to β-actin. C. APP-CTFs levels assessed by quantifying APP-CTFs in the Western blot. APP siRNA treatment significantly decreases protein levels of APP-CTFs as compared to control siRNA (**p < 0.01), normalized to β-actin. D. Numb protein levels assessed by quantifying Numb in the Western blot. APP siRNA treatment significantly decreases protein levels of Numb as compared to control siRNA treatment (*p < 0.05), normalized to β-actin.