Increased kidney RelB and NFκB2 expression and evidence for noncanonical NFκB activation in acute folate nephropathy. Kidney mRNA levels (A and C) were assessed by quantitative RT-PCR and protein levels by Western blot (B and D). (A) RelB mRNA, *p<0.01 versus vehicle. (B) RelB protein, *p<0.03 versus vehicle. (C) NFκB2 mRNA, *p<0.01 versus vehicle. (D) NFκB2 p100 and p52 proteins, representative Western blot. (E) NFκB2 p100 and p52 protein quantification, *p<0.03 and **p<0.05 versus vehicle. NFκB2 p100 is processed to NFκB p52 by the proteasome. (F) Increased nuclear DNA-binding activity of NFκB2 p52 and RelB in folate nephropathy. A DNA-binding ELISA was used to quantify DNA-binding activity of NFκB2 p52 and RelB in nuclei obtained from kidneys 24 hours after induction of folate nephropathy or vehicle administration. *p<0.01 versus vehicle; n=6 animals per group.