Determining c-Myb protein levels can isolate functional hematopoietic stem cell subtypes

Research output: Contribution to journalArticle

Authors

  • Hiroshi Sakamoto
  • Naoki Takeda
  • Fumio Arai
  • Kentaro Hosokawa
  • Toshio Suda
  • Minetaro Ogawa

Colleges, School and Institutes

Abstract

The transcription factor c-Myb was originally identified as a transforming oncoprotein encoded by two avian leukemia viruses. Subsequently, through the generation of mouse models that affect its expression, c-Myb has been shown to be a key regulator of hematopoiesis, including having critical roles in hematopoietic stem cells (HSCs). The precise function of c-Myb in HSCs although remains unclear. We have generated a novel c-myb allele in mice that allows direct observation of c-Myb protein levels in single cells. Using this reporter line we demonstrate that subtypes of HSCs can be isolated based upon their respective c-Myb protein expression levels. HSCs expressing low levels of c-Myb protein (c-Myb(low) HSC) appear to represent the most immature, dormant HSCs and they are a predominant component of HSCs that retain bromodeoxyuridine labeling. Hematopoietic stress, induced by 5-fluorouracil ablation, revealed that in this circumstance c-Myb-expressing cells become critical for multilineage repopulation. The discrimination of HSC subpopulations based on c-Myb protein levels is not reflected in the levels of c-myb mRNA, there being no more than a 1.3-fold difference comparing c-Myb(low) and c-Myb(high) HSCs. This illustrates how essential it is to include protein studies when aiming to understand the regulatory networks that control stem cell behavior.

Details

Original languageEnglish
Pages (from-to)479-490
Number of pages12
JournalStem Cells
Volume33
Issue number2
Early online date22 Jan 2015
Publication statusPublished - Feb 2015

Keywords

  • Animals, Gene Expression Regulation, Genes, Reporter, Hematopoiesis, Hematopoietic Stem Cells, Mice, Proto-Oncogene Proteins c-myb