Figure 7. The effect of 25-hydroxylase knockdown on 1,25OH₂D₃ generation.

hGF and hPDLC from donors 2, 4 and 5 were treated with 1000 nM vitamin D₃ for 48 h after transfection with a siRNA oligonucleotide for CYP27A1 or a non-silencing control, and 1,25OH₂D₃ production was measured in supernatants(A) and cell lysates (B). When CYP27A1 was knocked down, the generation of 1,25OH₂D₃ decreased significantly compared to when CYP27A1 was not knocked down. The data are presented as the mean ± SE. * hGF or hPDLC generated significantly less 1,25OH₂D₃ with 1000 nM vitamin D₃ when CYP27A1 was knocked down (p<0.05).