R1MAb2 activates the FGF23 pathway in kidney epithelial cells.

(A) OK cells were treated with vehicle (Mock), R1MAb2 (0.5, 5, or 50 nM), or isotype control IgG (50 nM) for 24 hours, and the mRNA expression of indicated genes were determined by qPCR. The expression of each gene was normalized by the expression of actin in the same sample and shown as relative expression. N = 3. (B) Similar gene expression analysis in OK cells after treatment with an indicated antibody at 50 nM. N = 6. (C) mRNA expression in OK cells treated with scrambled or FGFR1 siRNA oligos, determined by qPCR. N = 6. (D) Cyp24a1 gene expression in OK cells after treatment with siRNA oligos and an indicated ligand. N = 6. The data represents means ± SEM. * p<0.05 or *** p<0.001 compared with the control group.