Effects of succinylacetone on dimethylsulfoxide-mediated induction of heme pathway enzymes in mouse Friend virus-transformed erythroleukemia cells

University Paris 7, Faculty of Medicine X. Bichat, Department of Biochemistry, Hospital Louis Mourier, 92701 Colombes, France
Experimental Cell Research (Impact Factor: 3.25). 11/1984; 154(2):474-484. DOI: 10.1016/0014-4827(84)90171-X


Heme has been reported to exert a control over its own biosynthesis and to affect the erythroid differentiation process at different sites. In this study, succinylacetone, a powerful inhibitor of δ-aminolevulinic acid dehydrase was used to block heme synthesis and to study the effects of heme depletion on the dimethylsulfoxide (DMSO)-mediated induction of the heme pathway enzymes in Friend virus-transformed erythroleukemia cells. The presence of succinylacetone in the medium during the DMSO treatment (1) potentiates the induction of δ-aminolevulinic acid synthetase (the first enzyme of the pathway) and this effect is reversed by the addition of exogenous hemin; (2) does not affect the induction of δ-aminolevulinic acid dehydrase (the second enzyme); (3) prevents the induction of porphobilinogen deaminase (the third enzyme), since no increase could be detected in either the enzyme activity or the immunoreactive protein and this effect could not be reversed by the addition of exogenous hemin; (4) does not affect the induction of ferrochelatase. The possible role of heme or of intermediate metabolites of the pathway on the induction of these enzymes during the erythroid differentiation process is discussed.

1 Read
  • [Show abstract] [Hide abstract]
    ABSTRACT: In many types of cells the synthesis of δ-aminolevulinic acid (ALA) limits the rate of heme formation. However, results from our laboratory with reticulocytes suggest that the rate of iron uptake from transferrin (Tf), rather than ALA synthase activity, limits the rate of heme synthesis in erythroid cells. To determine whether changes occur in iron metabolism and the control of heme synthesis durihg. Erythroid cell development Friend erythroleukemia cells induced to erythroid differentiation by dimethylsulfoxide (DMSO) were studied. While added ALA stimulated heme synthesis in uninduced Friend cells (suggesting ALA synthase is limiting) it did not do so in induced cells. Therefore the possibility was investigated that, in induced cells, iron uptake from Tf limits and controls heme synthesis. Several aspects of iron metabolism were investigated using the synthetic iron chelator salicylaldehyde isonicotinoyl hydrazone (SIH). Both induced and uninduced Friend cells take up and utilize Fe for heme synthesis directly from Fe-SIH without the involvement of transferrin and transferrin receptors and to a much greater extent than from saturating levels of Fe-Tf (20 μM). Furthermore, in induced Friend cells 100 μM Fe-SIH stimulated 2-l4C-glycine incorporation into heme up to 3.6-fold as compared to the incorporation observed with saturating concentrations of Fe-Tf. In contrast, Fe-SIH, even when added in high concentrations, did not stimulate heme synthesis in uninduced Friend cells but was able to do so as early as 24 to 48 h following induction. In addition, contrary to previous results with rabbit reticulocytes, Fe-SIH also stimulated globin synthesis in induced Friend cells above the level seen with saturating concentrations of transferrin. These results indicate that some step(s) in the pathway of iron from extracellular Tf to protoporphyrin, rather than the activity of ALA synthase, limits and controls the overall rate of heme and possibly hemoglobin synthesis in differentiating Friend erythroleukemia cells.
    Journal of Cellular Physiology 11/1986; 129(2):185 - 192. DOI:10.1002/jcp.1041290209 · 3.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Haem controls the rate of haem synthesis in erythroid cells by inhibiting iron incorporation from transferrin. The present results indicate that haem primarily inhibits the release of iron from transferrin subsequent to transferrin endocytosis and that the inhibition of transferrin endocytosis caused by relatively high concentrations of haem is a secondary effect. Low concentrations of haem (10-25 microM) significantly inhibit reticulocyte iron uptake and to a greater extent its incorporation into haem, but do not inhibit either the initial rate of transferrin uptake or its internalization by the cells.
    Biochemical Journal 05/1988; 251(1):105-9. DOI:10.1042/bj2510105 · 4.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 5-Aminolaevulinic acid (ALA) synthase activity was measured in highly purified preparations of age-matched human erythroblasts. Enzyme activity in immature normoblasts was four-fold higher than that found in late orthochromatic normoblasts. ALA synthase activity in the immature erythroblasts in primary acquired sideroblastic anaemia (PASA) was reduced and remained unchanged during further erythroid differentiation. The pattern of erythroblast ALA synthase activity in two patients with congenital dyserythropoietic anaemia (CDA) and in one patient with β-thalassaemia intermedia was similar to that found in PASA. This study has clearly demonstrated reduced erythroblast ALA synthase activity in PASA but has also found reduced enzyme activity in conditions in which ring sideroblasts are not prominent. This would suggest that haem synthesis is abnormal in PASA but that reduced erythroblast ALA synthase activity does not inevitably lead to ring sideroblast formation.
    British Journal of Haematology 07/1988; 69(2):281-5. DOI:10.1111/j.1365-2141.1988.tb07634.x · 4.71 Impact Factor
Show more