Rev-erbα inhibits EPO production in vitro. (A) HepG2 cells were treated with an increasing concentration of GSK4112 for 24 hours and expression of EPO is measured with qRT-PCR. (B-C) HepG2 cells were treated with DMOG or GSK4112 for 24 hours, and EPO expression was evaluated by qRT-PCR at the mRNA level (B) and ELISA at the protein level (C) in the cell culture supernatant. (D) qRT-PCR analysis of EPO in HepG2 cells ectopically expressed with Rev-erbα. (E) Overexpression (O.E) of Rev-erbα in HepG2 cells determined with the qRT-PCR analysis. Data are representative and mean ± SD from 3 independent experiments. ∗P < .05; ∗∗P < .01, compared with control or as indicated.