Disassociation of the macrophage-maturational effects of vitamin D from respiratory burst priming

• Published in: The Journal of biological chemistry Vol. 266; no. 17; pp. 10888 - 10892
• Main Authors: TANAKA, H, KRUSKA, K. A, SEINO, Y, MALONE, J. D, NISHII, Y, TEITELBAUM, S. L
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 15.06.1991
• Subjects: Antineoplastic Agents - pharmacology; Biological and medical sciences; Calcitriol - analogs & derivatives; Calcitriol - metabolism; Calcitriol - pharmacology; Calcium - metabolism; Cell Differentiation - drug effects; Cell differentiation, maturation, development, hematopoiesis; Cell Line; Cell physiology; Cytoplasm - metabolism; Fundamental and applied biological sciences. Psychology; Humans; Leukemia, Promyelocytic, Acute; Macrophages - cytology; Macrophages - drug effects; Molecular and cellular biology; N-Formylmethionine Leucyl-Phenylalanine - pharmacology; Receptors, Calcitriol; Receptors, Formyl Peptide; Receptors, Immunologic - drug effects; Receptors, Immunologic - metabolism; Receptors, Steroid - drug effects; Receptors, Steroid - metabolism; Superoxides - metabolism; Tetradecanoylphorbol Acetate - pharmacology; Human; Signal transduction; Calcium; Vitamin D; Reaction mechanism; Respiratory burst; Cell differentiation; Macrophage
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)99102-7

During the process of enhancing monocytic differentiation of the human leukemia line HL-60, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) also "primes" the cell for respiratory burst by increasing the uptake of Ca2+ across the plasma membrane (Hruska, K.A., Bar-Shavit, Z., Malone, J.D., and Teitelbaum, S.L. (1988) J. Biol. Chem. 263, 16039-16044). The present study asked if the maturational effect of vitamin D is dependent upon this "priming" phenomenon. To this end, we exposed HL-60 to either 1,25(OH)2D3 or its synthetic analogue (1 alpha, 3 beta, 5Z, 7E)-9-10-Secocholesta-5,7,10(19)-triene-1, 3, 25-triol (22-oxa). We found that 22-oxa induced HL-60 maturation as effectively as does the natural steroid. As expected, 48 h of 1,25(OH)2D3 exposure more than doubles (p less than 0.005) HL-60 basal cytosolic Ca2+ and increases inositol triphosphate-sensitive Ca2+ stores approximately 4-fold (p less than 0.01). 22-oxa in contrast alters neither Ca(2+)- nor inositol triphosphate-mobilizable deposits. Moreover, 1,25(OH)2D3 treatment prompts a transient Ca2+ "spike" in response to formyl-methionyl-leucyl-phenylalanine (fMLP) and a marked increase in superoxide (O-2) generation when exposed to the chemotactic peptide (p less than 0.01) or phorbol ester (p less than 0.02). Treatment with 22-oxa does not enable HL-60 to respond to fMLP with a Ca2+ spike or prime the cell for respiratory burst unless it is co-incubated with the Ca2+ ionophore, ionomycin. Similarly, phorbol ester impacts more profoundly on O-2 generation by 1,25(OH)2D3 than 22-oxa preincubated cells (p less than 0.02), unless the latter is added with ionomycin. Our findings indicate that the maturational effects of vitamin D sterols are independent of their capacity to prime cells for respiratory burst and that the Ca2+ ionophoretic effects of 1,25(OH)2D3 play a major role in such priming.