Related Experiment Video
Updated: Jul 15, 2026
Identifying Bone Marrow Microenvironmental Populations in Myelodysplastic Syndrome and Acute Myeloid Leukemia
Published on: November 10, 2023
CD41+/CD45+ cells without acetylcholinesterase activity are immature and a major megakaryocytic population in murine
Kuniko Matsumura-Takeda1, Shinji Sogo, Yoshimasa Isakari
1Molecular Medical Science Institute, Otsuka Pharmaceutical Co. Ltd., 463-10 Kagasuno, Tokushima, Japan.
Abstract:
Murine megakaryocytes (MKs) are defined by CD41/CD61 expression and acetylcholinesterase (AChE) activity; however, their stages of differentiation in bone marrow (BM) have not been fully elucidated. In murine lineage-negative (Lin(-))/CD45(+) BM cells, we found CD41(+) MKs without AChE activity (AChE(-)) except for CD41(++) MKs with AChE activity (AChE(+)), in which CD61 expression was similar to their CD41 level. Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs could differentiate into AChE(+), with an accompanying increase in CD41/CD61 during in vitro culture. Both proplatelet formation (PPF) and platelet (PLT) production for Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs were observed later than for Lin(-)/CD41(++)/CD45(+)/AChE(+) MKs, whereas MK progenitors were scarcely detected in both subpopulations. GeneChip and semiquantitative polymerase chain reaction analyses revealed that the Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs are assigned at the stage between the progenitor and PPF preparation phases in respect to the many MK/PLT-specific gene expressions, including beta1-tubulin. In normal mice, the number of Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs was 100 times higher than that of AChE(+) MKs in BM. When MK destruction and consequent thrombocytopenia were caused by an antitumor agent, mitomycin-C, Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs led to an increase in AChE(+) MKs and subsequent PLT recovery with interleukin-11 administration. It was concluded that MKs in murine BM at least in part consist of immature Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs and more differentiated Lin(-)/CD41(++)/CD45(+)/AChE(+) MKs. Immature Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs are a major MK population compared with AChE(+) MKs in BM and play an important role in rapid PLT recovery in vivo.
Insights
Murine megakaryocytes (MKs) include immature CD41+ acetylcholinesterase-negative (AChE-) cells and mature CD41++ AChE+ cells. Immature MKs are more abundant and crucial for platelet recovery following chemotherapy.
Area of Science:
- Hematology
- Cell Biology
- Molecular Biology
Background:
- Murine megakaryocytes (MKs) are identified by CD41/CD61 expression and acetylcholinesterase (AChE) activity.
- The precise differentiation stages of MKs within the bone marrow (BM) remain incompletely understood.
Purpose of the Study:
- To elucidate the differentiation stages of murine MKs in bone marrow.
- To investigate the distinct roles of AChE-negative and AChE-positive MK subpopulations in platelet production and recovery.
Main Methods:
- Flow cytometry analysis of bone marrow cells to identify and quantify MK subpopulations based on CD41, CD61, CD45, and AChE expression.
- In vitro culture to assess the differentiation potential of MK subpopulations.
- Gene expression analysis (GeneChip, RT-PCR) to characterize MK-specific gene profiles.
- Pharmacological induction of thrombocytopenia using mitomycin-C, followed by interleukin-11 administration to evaluate platelet recovery.
Main Results:
- Two distinct murine MK subpopulations were identified: immature Lin(-)/CD41(+)/CD45(+)/AChE(-) MKs and more differentiated Lin(-)/CD41(++)/CD45(+)/AChE(+) MKs.
- Immature AChE(-) MKs are significantly more abundant (100-fold) in normal BM and differentiate into AChE(+) MKs in vitro, with delayed proplatelet formation and platelet production compared to AChE(+) MKs.
- In response to mitomycin-C-induced thrombocytopenia, immature AChE(-) MKs contribute to an increase in AChE(+) MKs, facilitating subsequent platelet recovery with interleukin-11 administration.
Conclusions:
- Murine bone marrow contains at least two major MK subpopulations: immature AChE(-) and differentiated AChE(+) MKs.
- Immature AChE(-) MKs represent the predominant MK population in BM and play a critical role in rapid platelet recovery in vivo.
- Understanding these distinct MK stages is vital for developing targeted therapies for thrombocytopenia.
