FIG 4.

Intracellular lipid abundance affects CIDEB protein stability. (A) Effect of two structurally distinct lipid droplet inhibitors, PF-429242, a reversible inhibitor of cholesterol synthesis, and Triacsin C, an inhibitor of long-chain-fatty-acid acyl-CoA synthetase, on LDs in Huh-7.5 cells. Cells were treated with 40 μM PF-429242 or 5.5 μM TriC for 24 h before staining with ORO. (B) Cell viability was measured after 24 h of treatment with the indicated compounds. (C and D) Western blot analysis of CIDEB protein levels in Huh-7.5 cells treated with PF-429242 or TriC for 24 h. Shown is quantification of CIDEB protein levels on a Western blot by ImageJ analysis (analyzed from biological triplicates). Ku80 was used as a loading control. (E) A 24-h treatment of Huh-7.5 cells with PF-429242 or TriC does not significantly alter CIDEB mRNA levels. (F and G) Effect of exogenous lipid loading on CIDEB protein in infected cells. Uninfected or (24-h) JFH-1/AD16-infected Huh-7.5 cells were treated with 100 μM OA for 20 h before being fixed for ORO staining or lysed for Western blot analysis.