1,25-Dihydroxy-vitamin-D3 enhances antiproliferative effect and transcription of TGF-beta1 on human keratinocytes in culture.
Both TGF-beta and 1,25-dihydroxy-vitamin-D3 (1,25(OH)2D3) have been reported to decrease the proliferation of normal human keratinocytes. The effect and expression of TGF-beta in keratinocytes treated with 1,25(OH)2D3 was investigated. Human keratinocytes were grown in the presence of various concentrations of TGF-beta and/or 1,25(OH)2D3 prior to enumeration. TGF-beta, alone, has a half maximal dose of inhibition (ED50) of approximately 750 pg/ml after seven days in culture in Keratinocyte Growth Medium (KGM; Clonetics) supplemented with 1.5 mM calcium. When 1,25(OH)2D3 (10(-7)M) was also added to cultures with various concentrations of TGF-beta, the ED50 shifted an average of 2-fold less. The presence of TGF-beta (10 pg/ml) augmented the potency of 1,25(OH)2D3 by at least 10-fold. In keratinocyte cultures, the antiproliferative effect of the two compounds together is synergistic. In keratinocytes grown for 1 week in the presence of 1,25(OH)2D3 at 10(-6)M, the TGF-beta 1 message increased approximately 5-fold. An increase is detected within 2 hours of exposure to 1,25(OH)2D3. There was only a 50% increase in the levels of TGF-beta 2 and no detection of TGF-beta 3. When keratinocyte cultures were treated with 1,25(OH)2D3 and neutralizing antibodies to TGF-beta, the induced-antiproliferative activity was blocked by more than 50%. The keratinocytes produced more active than latent TGF-beta after growth with high doses of 1,25(OH)2D3.
Kim
H J
HJ
Roche Dermatologics, Preclinical Research, Hoffmann-La Roche, Nutley, New Jersey 07110-1199.
Abdelkader
N
N
Katz
M
M
McLane
J A
JA
D000906:Antibodies / Q000276:immunology; D002117:Calcitriol / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004357:Drug Synergism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*
D000906:Antibodies; D016212:Transforming Growth Factor beta; D002117:Calcitriol