Figure 3. CYP27B1 is increased in response to injury, TGF-β₁, or activation of TLR2.

(A) The expression of CYP27B1, which converts inactive 25D3 to active 1,25D3, was evaluated in skin wounds as in Figure 1. Wounded skin (n = 5) increased CYP27B1 mRNA compared with controls (n = 4). *P < 0.05, Mann-Whitney test. (B) Keratinocytes were cultured in the presence of TNF-α (20 ng/ml) or TGF-β₁ (1 μg/ml) for 24 hours, after which RNA was isolated and CYP27B1 transcript abundance was analyzed by qPCR. (C) Keratinocytes were cultured with different TLR ligands for 24 hours, after which CYP27B1 expression analyzed as described above. Both TGF-β₁ and the TLR2 ligand Malp-2 induced CYP27B1 expression. 19-kDa, 19-kDa lipopeptide; LTA, lipoteichoic acid. Data are mean ± SD of a single experiment performed in triplicate and are representative of 3 independent experiments. *P < 0.05, **P < 0.01, Student’s t test.