Effect of pretreatment with the Nrf2 inducer tert-butyl hydroquinone (tBHQ) on mRNA expression of the antioxidant genes HMOX1 and GCLM. HTR-8/SVneo cells were pretreated with tBHQ, and then exposed to solvent control (No BDE-47, 0.7% v/v DMSO) or BDE-47 for 24 h. Bars represent means±SEM fold change over control (dashed line, No BDE-47 with 0 μM tBHQ). The target gene expression from each sample was first normalized to the housekeeping gene B2M, and then fold changes were calculated relative to the normalized control (n=3 experiments). Each experiment was performed in triplicate. A) The mRNA expression of HMOX1. B) The mRNA expression of GCLM. *P<0.05, compared to control (dashed line). #P<0.05, significantly different compared to cells in No BDE-47 group receiving the same Nrf2 inducer treatment. &P<0.05, compared to no pretreatment (0 μM tBHQ) in BDE-47-treated cells.