Fig 4. Changes in bone FGF23 expression with doxercalciferol therapy.

a) The quantification of FGF23 mRNA (qRT-PCR) transcript and FGF23 protein as detected by immunohistochemistry (IHC). For qRT-PCR, gene expression in dialysis patients before and after doxercalciferol therapy was expressed relative to normal control and was calculated as 2^(ΔCt FGF23)/2^ (ΔCt GAPDH). Individual data points are shown; the bar indicates the median value. The number sign indicates a significant (p<0.05) change from baseline. b) Western blot analysis of bone extract for FGF23 demonstrated only the presence of full-length (36 kDa) FGF23 in 5 separate dialysis patients and an increase in full-length FGF23 expression with doxercalciferol. Abbreviations: Ctr: healthy control; Pt: patient. The asterisk indicates a significant (p<0.05) change from baseline