Activated HoxB4-induced hematopoietic stem cells from murine pluripotent stem cells via long-term programming

• Published in: Experimental hematology Vol. 89; pp. 68 - 79.e7
• Main Authors: Izawa, Kiyoko, Yamazaki, Satoshi, Becker, Hans J, Bhadury, Joydeep, Kakegawa, Tomoya, Sakaguchi, Momoko, Tojo, Arinobu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2020
• Subjects: Animals; Cell Differentiation - drug effects; Cell Proliferation; Cellular Reprogramming - drug effects; Cellular Reprogramming - genetics; Gene Expression Regulation; Hematopoiesis - drug effects; Hematopoiesis - genetics; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - drug effects; Hematopoietic Stem Cells - metabolism; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - drug effects; Induced Pluripotent Stem Cells - metabolism; Leukocyte Common Antigens - genetics; Leukocyte Common Antigens - metabolism; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutant Chimeric Proteins - genetics; Mutant Chimeric Proteins - metabolism; Primary Cell Culture; Receptors, Estrogen - genetics; Receptors, Estrogen - metabolism; Stem Cell Factor - pharmacology; Tamoxifen - analogs & derivatives; Tamoxifen - pharmacology; Thrombopoietin - pharmacology; Transcription Factors - genetics; Transcription Factors - metabolism; Whole-Body Irradiation
• ISSN: 0301-472X; 1873-2399
• DOI: 10.1016/j.exphem.2020.08.003

•Continuous activation of HoxB4 generated c-kit+FLK–CD31+CD45– cells from iPSCs.•c-kit+FLK–CD31+CD45– cells showed long-term reconstitution in bone marrow.•The intranuclear localization of HoxB4 controls differentiation arrest in vitro.•The intranuclear localization of HoxB4 enhances gene expression governing stemness. Hematopoietic stem cells (HSCs) are multipotent cells that form the entire blood system and have the potential to cure several pathogenic conditions directly or indirectly arising from defects within the HSC compartment. Pluripotent stem cells (PSCs) or induced pluripotent stem cells (iPSCs) can give rise to all embryonic cell types; however, efficient in vitro differentiation of HSCs from PSCs remains challenging. HoxB4 is a key regulator orchestrating the differentiation of PSCs into all cells types across the mesodermal lineage, including HSCs. Moreover, the ectopic expression of HoxB4 enhances the in vitro generation and expansion of HSCs. However, several aspects of HoxB4 biology including its regulatory functions are not fully understood. Here, we describe the role of HoxB4 in indirectly inhibiting the emergence of mature CD45+ HSCs from iPSCs in vitro. Forced activation of HoxB4 permitted long-term maintenance of functional hematopoietic stem and progenitor cells (HSPCs), which efficiently reconstituted hematopoiesis upon transplantation. Our method enables an easy and scalable in vitro platform for the generation of HSCs from iPSCs, which will ultimately lead to a better understanding of HSC biology and facilitate preparation of the roadma for producing an unrestricted supply of HSCs for several curative therapies.