Cellular sterol levels regulate Pdro expression.
(A) Manipulation of cellular cholesterol levels were performed by treating cells with the indicated AcLDL concentrations for 24h to stimulate cholesterol loading, or using the indicated concentrations of compactin for 24h to reduce cellular cholesterol. Pdro mRNA levels quantified by real-time PCR are expressed as relative units after internal normalization to TBP mRNA levels and compared with control samples in the absence of treatment. Values represent the mean ± SD of three independent experiments (*, p≤0.05 using Mann Whitney test). (B) Cellular lysates from these AcLDL or compactin treated cells were subjected to SDS-PAGE and immunoblotted with antibodies against endogenous Pdro. Actin served as loading controls. (C) SHEP cells were treated with siPdro or a control scramble siRNA (scramble). After 72h, cellular lysates were analyzed for Pdro mRNA content by Northern Blotting (mRNA) or for Pdro (protein) content by immunoblotting using anti-Pdro antibody. Actin served as loading controls.