Fig. 8.

Sortilin overexpression increases internalization of Lp(a), but not apo(a), by HepG2 cells. Cells were transiently transfected with expression vectors encoding sortilin or the corresponding empty vector (pcDNA), as indicated. Cells were grown for 16 h in LPDS media and subsequently incubated for 4 h with 10 μg/ml Lp(a) (A) or 200 nM 17K apo(a) (B), each in the presence or absence of 200 mM ε-ACA. The cells were extensively washed, and lysates were subjected to Western blot analysis to determine the amount of Lp(a)/apo(a) internalized. The data shown are normalized using the β-actin signal as an internal control and correspond to the means ± SEM of at least three independent experiments. Significance compared to pcDNA is indicated through asterisks, where ∗∗P<0.01. Significance between cells treated with ε-ACA and nontreated cells is indicated through daggers, where †P<0.05 and ††P<0.01. apo(a), apolipoprotein(a); Lp(a), lipoprotein(a); LPDS, lipoprotein-deficient serum.