title: An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors.
abstract: Hematopoietic stem cells (HSCs) are considered one of the most promising therapeutic targets for the treatment of various blood disorders. However, due to difficulties in establishing stable maintenance and expansion of HSCs in vitro, their insufficient supply is a major constraint to transplantation studies. To solve these problems we have developed a fully defined, all-recombinant protein-based culture system. Through this system, we have identified hemopexin (HPX) and interleukin-1α as responsible for HSC maintenance in vitro. Subsequent molecular analysis revealed that HPX reduces intracellular reactive oxygen species levels within cultured HSCs. Furthermore, bone marrow immunostaining and 3D immunohistochemistry revealed that HPX is expressed in non-myelinating Schwann cells, known HSC niche constituents. These results highlight the utility of this fully defined all-recombinant protein-based culture system for reproducible in vitro HSC culture and its potential to contribute to the identification of factors responsible for in vitro maintenance, expansion, and differentiation of stem cell populations.
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Ieyasu
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Ishida
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Kimura
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Morita
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Lorry I. Lokey Stem Cell Research Building, 265 Campus Drive, Stanford, CA 94305-5461, USA.
authors.forename: Adam C
authors.initials: AC
authors.lastname: Wilkinson
authors.affiliation: Cell Engineering Division, BioResource Center, RIKEN, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sudo
authors.affiliation: Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Lorry I. Lokey Stem Cell Research Building, 265 Campus Drive, Stanford, CA 94305-5461, USA.
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Nishimura
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Ohehara
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tajima
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Chen-Yi
authors.initials: CY
authors.lastname: Lai
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Otsu
authors.affiliation: Cell Engineering Division, BioResource Center, RIKEN, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical Collage, 288 Nanjing Road, Tianjin 300020, China.
authors.forename: Hideo
authors.initials: H
authors.lastname: Ema
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Lorry I. Lokey Stem Cell Research Building, 265 Campus Drive, Stanford, CA 94305-5461, USA. Electronic address: nakauchi@ims.u-tokyo.ac.jp.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakauchi
authors.affiliation: Laboratory of Stem Cell Therapy, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Project Division of Advanced Regenerative Medicine, The Institute of Medical Science, the University of Tokyo, Tokyo 108-8639, Japan. Electronic address: y-sato4@ims.u-tokyo.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamazaki
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D000066673:Cell Self Renewal / Q000187:drug effects; D003114:Colony-Forming Units Assay; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D006466:Hemopexin / Q000494:pharmacology; D053582:Interleukin-1alpha / Q000494:pharmacology; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology*
chemical_list: D001798:Blood Proteins; D053582:Interleukin-1alpha; D011994:Recombinant Proteins; D006466:Hemopexin
keywords: BSA; FCS; all-recombinant protein-based culture system; hematopoietic stem cell; hemopexin