Nrf2 knockout attenuates LPS-induced inflammatory response in pbMECs. Cells were transfected with siRNA targeting Nrf2 or a negative control (NC) siRNA for 48 h, and the efficiency of Nrf2 knockdown was confirmed by RT-qPCR (left panel) and Western blotting (right panel). β-actin was used for the equal loading control (A). The cells were then incubated with LPS (10 μg/mL) for the indicated time. Cell viability was determined by MTT assay. The results are the mean ± s.d. of six replicates (B). The cells were then lysed with RIPA lysis buffer and subjected to immunoblot analysis against Nrf2, phosphor-IκBα (p-IκBα) and NF-κB p65 (p-p65) by using anti-Nrf2, anti-pIκBα, and anti-pNF-κB p65 antibodies, respectively. β-actin was used for the equal loading control. p-p65 and p- IκBα levels were quantified with densitometry analyses after normalization to Actin. Bars are means ± s.d. of three triplicates and are representative of 3 separate experiments (C). Total RNAs were prepared and subjected to qPCR analyses for the mRNA levels of IL-1β, TNF-α, IL-6 and IL-8. The results are the mean ± s.d. of three replicates and are representative of 3 separate experiments (D). * p < 0.05.