R. Yamamoto Group
Stem Cell Biology & Hematology
Stem cells are characterized by two features, self-renewal activity and multipotency. Stem cells themselves gradually change with aging, causing several kinds of diseases and defects. However, the biology and mechanisms are to be determined. Our group focuses on blood stem cells (hematopoietic stem cells, HSCs) among several kinds of stem cells.
HSCs reside at the top of the hierarchy of the hematopoietic system. The aging and dysfunction of this long-lived adult stem cell populations are thought to underlie the hematopoietic system decline and dysfunction associated with physiological aging or diseases. Age-related dysfunction of the hematopoietic system includes reduced lymphopoiesis and excessive myeloid production. The acquisition of specific somatic mutations in HSCs results in clonal hematopoiesis with aging, which is a clonally expanded blood system originating from the mutated HSCs. The genomic landscape in clonal hematopoiesis and myeloid malignancies provided insights into the evolution of hematopoietic malignancies from clonal hematopoiesis with aging. However, the mechanisms underlying clonal hematopoiesis and myeloid malignancies remains to be assessed. A better understanding of these mechanisms is critical to promote healthy aging.
Wilkinson, A. C.*, R. Ishida*, M. Kikuchi, K. Sudo, M. Morita, R. V. Crisostomo, R. Yamamoto, K. M. Loh, Y. Nakamura, M. Watanabe, H. Nakauchi, and S. Yamazaki. “Long-term ex vivo expansion of hematopoietic stem cells affords non-conditioned transplantation.” Nature, 571(2019): 117-121. （*Equal contribution）
Yamamoto, R.*, A. C. Wilkinson*, and H. Nakauchi. “Changing concepts in hematopoietic stem cells.”Science, 362 (2018): 895-96.（*Equal contribution）
Yamamoto, R., A. C. Wilkinson, J. Ooehara, X. Lan, C. Y. Lai, Y. Nakauchi, J. K. Pritchard, and H. Nakauchi. “Large-Scale Clonal Analysis Resolves Aging of the Mouse Hematopoietic Stem Cell Compartment.” Cell Stem Cell, 22 (2018): 600-07 e4.
Ghosn, E. E., J. Waters, M. Phillips, R. Yamamoto, B. R. Long, Y. Yang, R. Gerstein, C. A. Stoddart, H. Nakauchi, and L. A. Herzenberg. “Fetal Hematopoietic Stem Cell Transplantation Fails to Fully Regenerate the B-Lymphocyte Compartment.” Stem Cell Reports, 6 (2016): 137-49.
Matsunawa, M.*, R. Yamamoto*, M. Sanada*, A. Sato-Otsubo, Y. Shiozawa, K. Yoshida, M. Otsu, Y. Shiraishi, S. Miyano, K. Isono, H. Koseki, H. Nakauchi, and S. Ogawa. “Haploinsufficiency of Sf3b1 Leads to Compromised Stem Cell Function but Not to Myelodysplasia.” Leukemia, 28 (2014): 1844-50.（*Equal contribution）
Yamamoto, R.*, Y. Morita*, J. Ooehara, S. Hamanaka, M. Onodera, K. L. Rudolph, H. Ema, and H. Nakauchi. “Clonal Analysis Unveils Self-Renewing Lineage-Restricted Progenitors Generated Directly from Hematopoietic Stem Cells.” Cell, 154 (2013): 1112-26.（*Equal contribution）
Ghosn, E. E., R. Yamamoto, S. Hamanaka, Y. Yang, L. A. Herzenberg, H. Nakauchi, and L. A. Herzenberg. “Distinct B-Cell Lineage Commitment Distinguishes Adult Bone Marrow Hematopoietic Stem Cells.” Proc Natl Acad Sci USA, 109 (2012): 5394-8.
Yoshida, K*., M. Sanada*, Y. Shiraishi*, D. Nowak*, Y. Nagata*, R. Yamamoto, Y. Sato, A. Sato-Otsubo, A. Kon, M. Nagasaki, G. Chalkidis, Y. Suzuki, M. Shiosaka, R. Kawahata, T. Yamaguchi, M. Otsu, N. Obara, M. Sakata-Yanagimoto, K. Ishiyama, H. Mori, F. Nolte, W. K. Hofmann, S. Miyawaki, S. Sugano, C. Haferlach, H. P. Koeffler, L. Y. Shih, T. Haferlach, S. Chiba, H. Nakauchi, S. Miyano, and S. Ogawa. “Frequent Pathway Mutations of Splicing Machinery in Myelodysplasia.” Nature, 478 (2011): 64-9.（*Equal contribution）
Yamamoto, R., M. Nishikori, M. Tashima, T. Sakai, T. Ichinohe, A. Takaori-Kondo, K. Ohmori, and T. Uchiyama. “B7-H1 Expression Is Regulated by Mek/Erk Signaling Pathway in Anaplastic Large Cell Lymphoma and Hodgkin Lymphoma.” Cancer Sci, 100 (2009): 2093-100.
Yamamoto, R., M. Nishikori, T. Kitawaki, T. Sakai, M. Hishizawa, M. Tashima, T. Kondo, K. Ohmori, M. Kurata, T. Hayashi, and T. Uchiyama. “PD-1-PD-1 Ligand Interaction Contributes to Immunosuppressive Microenvironment of Hodgkin Lymphoma.” Blood, 111 (2008): 3220-4.