Figure 5. Pdro knockdown stimulates LDL uptake, macropinocytosis and cholesterol efflux.

(A) For LDL uptake, cells pre-treated for 72h with the indicated siRNA and further incubated for 12h with [³H] cholesteryl oleate-labelled AcLDL (50 µg/ml) in lipoprotein lipoprotein-deficient serum. (B) For macropinocytosis determination, cells pre-treated for 72h with the indicated siRNA were incubated or not with RITC-dextran (2.5mg/ml) for various time, extensively washed and fixed with 4% PFA, and analyzed by flow cytometry. Values are compared with control samples in with RITC-dextran was omitted. (C) Cholesterol efflux to apoA-1 during 18h from SHEP was determined by incubating cells pre-treated for 72h with the indicated siRNA, with [³H] cholesterol and further incubation in serum-free medium containing 0.2% bovine serum albumin in the presence or absence of 10µg/ml apoA-I. Values are expressed as percentage of cholesterol efflux. Values represent the mean ± SD of three independent experiments (*, p≤0.05 using Mann Whitney test).