Cellular redox state and activating protein-1 are involved in ascorbate effect on calcitriol-induced differentiation.
Ascorbate has been related to the differentiation of several mesenchymal cells including haematopoietic cells. We have previously demonstrated that ascorbate enhances the activity of 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3) on monocytic differentiation of HL-60 cells. Here, we show that ascorbate-mediated modification of cellular redox state and AP-1 (activating protein-1) DNA binding during early phases are related to the enhancing effect of ascorbate on differentiation. Ascorbate, but not its fully oxidized form, dehydroascorbate, or an ascorbate analogue with a low rate of oxidation, ascorbate-2-phosphate, enhanced the differentiation induced by 1 alpha,25(OH)2D3, modified cytosolic reactive oxygen species levels and mitochondrial redox potential (delta psi m), and modulated AP-1 DNA binding in HL-60 cells. Ascorbate itself increased AP-1 binding to DNA in noninduced cells, whereas it inhibited AP-1 binding in 1 alpha,25(OH)2D3-induced cells. However, ascorbate increased the mRNA levels of c-jun, junB, and c-fos in 1 alpha,25(OH)2D3-induced cells. Taken together, these results suggest that the enhancing effect of ascorbate on HL-60 differentiation induced by 1 alpha, 25(OH)2D3 is related to its effect on the cellular redox state and the modulation of AP-1 activity.
López-Lluch
G
G
Laboratorio Andaluz de Biología, Universidad Pablo de Olavide, Sevilla, Carretera de Utrera, Km 1.0, 41013 Sevilla, Spain.
Blázquez
M V
MV
Pérez-Vicente
R
R
Macho
A
A
Burón
M I
MI
Alcaín
F J
FJ
Muñoz
E
E
Navas
P
P
D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology*; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D004247:DNA / Q000378:metabolism; D000431:Ethanol / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism; D010084:Oxidation-Reduction; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D017382:Reactive Oxygen Species; D018808:Transcription Factor AP-1; D000431:Ethanol; D004247:DNA; D002117:Calcitriol; D001205:Ascorbic Acid