Perrin M C, Blanchet J P, Mouchiroud G
Centre de Génétique Moléculaire et Cellulaire, UMR CNRS 5534, Université Claude Bernard Lyon I, Villeurbanne, France.
Hematol Cell Ther. 1997 Feb;39(1):19-26. doi: 10.1007/s00282-997-0019-2.
Receptors for L-triiodothyronine (T3) and alltrans retinoic acid (ATRA) are DNA-binding proteins that can form transcriptionally active heterodimers. In this study, we sought whether T3 and ATRA could cooperate to modulate human and mouse erythropoiesis in vitro. Effects of T3 and ATRA were first assessed on burst forming unit-erythroid (BFU-E) proliferation and differentiation in semi-solid cultures. T3 did not alter the cloning efficiency of BFU-E but it decreased the production of colony forming unit-erythroid (CFU-E) during the course of BFU-E development. In contrast to T3, ATRA inhibited the early steps of BFU-E proliferation. ATRA and T3 acted in a dose-dependent manner with optimal effects at 10(-6) M and 10(-8) M, respectively. Furthermore, T3 and ATRA used in combination had more pronounced effects than when used alone, but only at their respective optimal concentrations, indicating that these effects were additive rather than synergistic. Similar results were obtained with unfractionated mouse bone marrow cells or human CD34+ bone marrow cells, suggesting that the effects of T3 or ATRA were not mediated by accessory cells. This study was extended to the mouse IL-3-dependent NFS-60 cells that can differentiate in vitro into mature erythroid cells in response to erythropoietin (Epo). When used alone, neither T3 nor ATRA could affect NFS-60 cell proliferation in response to Epo; however, T3 and ATRA had an anti-proliferative effect when used together. In addition, T3-dramatically reduced the proportion of hemoglobinized colonies in Epo-stimulated cultures of NFS-60 cells. Furthermore, ATRA, but not T3, could inhibit the IL-3-dependent proliferation of NFS-60 cells. Altogether these data suggest that T3 and ATRA can cooperate in modulating in vitro erythropoiesis although having individual effects at different but overlapping steps along the erythroid pathway.
L-三碘甲状腺原氨酸（T3）和全反式维甲酸（ATRA）的受体是能够形成具有转录活性异二聚体的DNA结合蛋白。在本研究中，我们探究了T3和ATRA是否能在体外协同调节人和小鼠的红细胞生成。首先在半固体培养中评估T3和ATRA对红系爆式集落形成单位（BFU-E）增殖和分化的影响。T3不会改变BFU-E的克隆效率，但在BFU-E发育过程中会减少红系集落形成单位（CFU-E）的产生。与T3相反，ATRA抑制BFU-E增殖的早期步骤。ATRA和T3呈剂量依赖性作用，最佳效应浓度分别为10^(-6) M和10^(-8) M。此外，T3和ATRA联合使用比单独使用具有更显著的效应，但仅在各自的最佳浓度时如此，表明这些效应是相加而非协同的。用未分级的小鼠骨髓细胞或人CD34+骨髓细胞也获得了类似结果，提示T3或ATRA的效应不是由辅助细胞介导的。本研究扩展至依赖小鼠白细胞介素-3（IL-3）的NFS-60细胞，该细胞在体外可响应促红细胞生成素（Epo）分化为成熟红细胞。单独使用时，T3和ATRA均不能影响NFS-60细胞对Epo的增殖反应；然而，T3和ATRA联合使用时具有抗增殖作用。此外，T3显著降低了Epo刺激的NFS-60细胞培养物中血红蛋白化集落的比例。再者，ATRA而非T3能抑制NFS-60细胞依赖IL-3的增殖。总之，这些数据表明T3和ATRA虽然在红系途径的不同但有重叠的步骤中具有各自的效应，但它们可以协同调节体外红细胞生成。
