NF-kappaB family proteins participate in multiple steps of hematopoiesis through elimination of reactive oxygen species.
To examine the roles for NF-kappaB family proteins in hematopoiesis, we first expressed dominant negative Rel/NF-kappaB(IkappaBSR) in a factor-dependent cell line, Ba/F3. Although IkappaBSR neither affected thrombopoietin-dependent nor gp130-mediated growth, it suppressed interleukin-3- and erythropoietin-dependent growth at low concentrations. In addition, IkappaBSR enhanced factor-deprived apoptosis through the accumulation of reactive oxygen species (ROS). When expressed in normal hematopoietic stem/progenitor cells, IkappaBSR induced apoptosis even in the presence of appropriate cytokines by accumulating ROS. We also expressed IkappaBSR in an inducible fashion at various stages of hematopoiesis using the OP9 system, in which hematopoietic cells are induced to develop from embryonic stem cells. When IkappaBSR was expressed at the stage of Flk-1(+) cells (putative hemangioblasts), IkappaBSR inhibited the development of primitive hematopoietic progenitor cells by inducing apoptosis through the ROS accumulation. Furthermore, when IkappaBSR was expressed after the development of hematopoietic progenitor cells, it inhibited their terminal differentiation toward erythrocytes, megakaryocytes, and granulocytes by inducing apoptosis through the ROS accumulation. These results indicate that NF-kappaB is required for preventing apoptosis at multiple steps of hematopoiesis by eliminating ROS.
Department of Hematology and Oncology, Osaka University Graduate School of Medicine, 2-2, Yamada-oka, Suita, Osaka 565-0871, Japan.
Soichi
S
Nakata
Itaru
I
Matsumura
Hirokazu
H
Tanaka
Sachiko
S
Ezoe
Yusuke
Y
Satoh
Jun
J
Ishikawa
Takumi
T
Era
Yuzuru
Y
Kanakura
D000818:Animals; D017209:Apoptosis; D015152:Blotting, Northern; D002460:Cell Line; D002469:Cell Separation; D002470:Cell Survival; D002478:Cells, Cultured; D004396:Coloring Agents / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D004921:Erythropoietin / Q000378:metabolism; D005434:Flow Cytometry; D005978:Glutathione / Q000378:metabolism; D006098:Granulocytes / Q000378:metabolism; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D020672:I-kappa B Proteins / Q000378:metabolism; D015151:Immunoblotting; D007377:Interleukin-3 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000737:chemistry* / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013752:Tetracycline / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors
D004396:Coloring Agents; D017077:Culture Media, Conditioned; D016207:Cytokines; D020672:I-kappa B Proteins; D007377:Interleukin-3; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; D004921:Erythropoietin; C022616:thiazolyl blue; D013752:Tetracycline; D005978:Glutathione