ERRα modulates local E2 production in the culture media of WPMY-1 cells. WPMY-1 cells were transfected with ERRα expression plasmid or ERRα siRNA for 6 h, and then stimulated with or without PGE2 (1 μm) for 48 h. At the end of the incubation period, testosterone (10 nm) was added, and cells were incubated for 24 h, and cultured media were collected and analyzed for E2 concentration using Estradiol II kit. Values represent the mean ± sd (n = 3). *, P < 0.05; **, P < 0.01 compared with the untreated controls.