TY - JOUR
T1 - C/EBPβ isoforms sequentially regulate regenerating mouse hematopoietic stem/progenitor cells
AU - Sato, Atsushi
AU - Kamio, Naoka
AU - Yokota, Asumi
AU - Hayashi, Yoshihiro
AU - Tamura, Akihiro
AU - Miura, Yasuo
AU - Maekawa, Taira
AU - Hirai, Hideyo
N1 - Funding Information:
Conflict-of-interest disclosure: H.H. received research funding from Kyowa Kirin, Bristol-Myers K.K., CSL Behring, Mitsubishi Tanabe Pharma, Sumitomo Dainippon Pharma, and Novartis Pharma. T.M. received research funding from Bristol-Myers K.K. The remaining authors declare no competing financial interests.
Funding Information:
The authors thank Toshio Kitamura (University of Tokyo) for providing Plat-E cells and Schickwann Tsai (University of Utah) for providing EML cells. The authors also thank Shigekazu Nagata (Osaka University) for providing CD45.1 mice. The authors gratefully acknowledge Naoko Watanabe-Okochi and Mineo Kurokawa (University of Tokyo) for kindly providing the pGCDNsam-IRESKusabira-Orange (KuO), pGCDNsam-LIP-KuO, pGCDNsam-LAPKuO, and pGCDNsam-LAP*-KuO vectors. The authors are also grateful to Yoko Nakagawa and Yoshiko Manabe for their excellent technical assistance. This work was partly supported by KAKENHI Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (25461415 and 18K08354 [H.H.], 25430149 [A.Y.], and 25112706 and 16K07171 [T.M.]); the Extramural Collaborative Research Grant from the Cancer Research Institute, Kanazawa University (H.H.); the Highway Program for Realization of Regenerative Medicine (JP17bm0504008) (H.H.); the Acceleration of Transformative Research for Medical Innovation from the Japan Agency for Medical Research and Development (H.H.); a grant from the Kyoto University Research Development Program "Ishizue" (H.H.); and a grant from the Kyoto University Foundation.
PY - 2020/7/28
Y1 - 2020/7/28
N2 - The transcription factor CCAAT enhancer-binding protein β (C/EBPβ) is required for stressinduced granulopoiesis at the level of hematopoietic stem/progenitor cells (HSPCs); however, its role and mechanisms of action in HSPCs are unknown. In this study, we assessed the regulation and functions of C/EBPβ in HSPCs, especially under stress conditions. After 5-fluorouracil treatment or bone marrow transplantation, Cebpb-/- HSPCs exhibited impaired cell-cycle activation and myeloid differentiation at the early and late phases of regeneration, respectively, whereas at steady state, Cebpb deficiency did not affect HSPCs. C/EBPβ was upregulated in response to hematopoietic stress, especially in CD150high long term-hematopoietic stem cells (LT-HSCs). Intracellular flow cytometric analysis that detected distinct domains of C/EBPβ revealed that, among the 3 isoforms of C/EBPβ, liver-enriched inhibitory protein (LIP) was upregulated in LT-HSCs prior to liver-enriched activating protein (LAP)/LAP∗ during regeneration. Early upregulation of LIP promoted cellcycle entry of LT-HSCs by positively regulating Myc and expanded the HSPCs pool. Subsequent myeloid differentiation of amplified HSPCs was mediated by LAP/LAP∗, which were upregulated at a later phase of regeneration. Collectively, our findings show that stress-induced sequential upregulation of C/EBPβ isoforms is critical for fine-tuning the proliferation and differentiation of regenerating HSPCs.
AB - The transcription factor CCAAT enhancer-binding protein β (C/EBPβ) is required for stressinduced granulopoiesis at the level of hematopoietic stem/progenitor cells (HSPCs); however, its role and mechanisms of action in HSPCs are unknown. In this study, we assessed the regulation and functions of C/EBPβ in HSPCs, especially under stress conditions. After 5-fluorouracil treatment or bone marrow transplantation, Cebpb-/- HSPCs exhibited impaired cell-cycle activation and myeloid differentiation at the early and late phases of regeneration, respectively, whereas at steady state, Cebpb deficiency did not affect HSPCs. C/EBPβ was upregulated in response to hematopoietic stress, especially in CD150high long term-hematopoietic stem cells (LT-HSCs). Intracellular flow cytometric analysis that detected distinct domains of C/EBPβ revealed that, among the 3 isoforms of C/EBPβ, liver-enriched inhibitory protein (LIP) was upregulated in LT-HSCs prior to liver-enriched activating protein (LAP)/LAP∗ during regeneration. Early upregulation of LIP promoted cellcycle entry of LT-HSCs by positively regulating Myc and expanded the HSPCs pool. Subsequent myeloid differentiation of amplified HSPCs was mediated by LAP/LAP∗, which were upregulated at a later phase of regeneration. Collectively, our findings show that stress-induced sequential upregulation of C/EBPβ isoforms is critical for fine-tuning the proliferation and differentiation of regenerating HSPCs.
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U2 - 10.1182/bloodadvances.2018022913
DO - 10.1182/bloodadvances.2018022913
M3 - Article
C2 - 32717031
AN - SCOPUS:85091970409
VL - 4
SP - 3343
EP - 3356
JO - Blood advances
JF - Blood advances
SN - 2473-9529
IS - 14
ER -