Figure 10.

LRP1 and cholesterol loading in hepatocytes act synergistically to activate hepatic stellate cells via the sonic hedgehog pathway. Primary hepatocytes isolated from hLrp1^+/+ (filled bars) and hLrp1^−/− (open bars) mice were incubated without (control) or with 20 μm cholesterol (+ chol) for 16 h. Conditioned media from these cell cultures were added to the T6 hepatic stellate cells, and incubation was continued for an additional 24 h in the presence or absence of a 10 μm concentration of the hedgehog signaling inhibitor cyclopamine or GANT-58. Total cellular RNA was isolated for RT-qPCR analysis of smooth muscle α-actin (A), desmin (B), and TGF-β (C). The data were analyzed using cyclophilin mRNA levels as control. Expression levels observed when T6 cells were incubated with hLrp1^+/+ hepatocyte conditioned medium in the absence of cholesterol were set as 1.0. The data represent mean ± S.E. from duplicate experiments, each performed with three biological replicate samples. *, significant differences at p < 0.05.