title: Clonal-level responses of functionally distinct hematopoietic stem cells to trophic factors.
abstract: Recent findings from several groups have identified distinct classes of hematopoietic stem cells (HSCs) in the bone marrow, each with inherent functional biases in terms of their differentiation, self-renewal, proliferation, and lifespan. It has previously been demonstrated that myeloid- and lymphoid-biased HSCs can be prospectively enriched based on their degree of Hoechst dye efflux. In the present study, we used differential Hoechst efflux to enrich lineage-biased HSC subtypes and analyzed their functional potentials. Despite similar outputs in vitro, bone marrow transplantation assays revealed contrasting lineage differentiation in vivo. To stratify the molecular differences underlying these contrasting functional potentials at the clonal level, single-cell gene expression analysis was performed using the Fluidigm BioMark system and revealed dynamic expression of genes including Meis1, CEBP/α, Sfpi1, and Dnmt3a. Finally, single-cell gene expression analysis was used to unravel the opposing proliferative responses of lineage-biased HSCs to the growth factor TGF-β1, revealing a potential role for the cell cycle inhibitor Cdkn1c as molecular mediator. This work lends further credence to the concept of HSC heterogeneity, and it presents unprecedented molecular resolution of the HSC response to trophic factors using single-cell gene expression analysis.
authors.affiliation: Division of Oncology, Section of Molecular Oncology, Department of Internal Medicine, Washington University in St. Louis, St. Louis, MO.
authors.forename: Cates
authors.initials: C
authors.lastname: Mallaney
authors.affiliation: Department of Pediatrics, Washington University in St. Louis, St. Louis, MO.
authors.forename: Alok
authors.initials: A
authors.lastname: Kothari
authors.affiliation: Division of Oncology, Section of Molecular Oncology, Department of Internal Medicine, Washington University in St. Louis, St. Louis, MO.
authors.forename: Andrew
authors.initials: A
authors.lastname: Martens
authors.affiliation: Division of Oncology, Section of Molecular Oncology, Department of Internal Medicine, Washington University in St. Louis, St. Louis, MO. Electronic address: gchallen@DOM.wustl.edu.
authors.forename: Grant A
authors.initials: GA
authors.lastname: Challen
mesh_terms: D064591:Allografts; D000818:Animals; D016026:Bone Marrow Transplantation; D022762:CCAAT-Enhancer-Binding Proteins / Q000096:biosynthesis; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000096:biosynthesis; D005786:Gene Expression Regulation / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000096:biosynthesis; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D051379:Mice; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D015534:Trans-Activators / Q000096:biosynthesis; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D050761:Cyclin-Dependent Kinase Inhibitor p57; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D000075064:Myeloid Ecotropic Viral Integration Site 1 Protein; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D053773:Transforming Growth Factor beta1; D000099232:Proto-Oncogene Protein Spi-1; C530718:CEBPA protein, mouse; C493965:Cdkn1c protein, mouse; C000616392:Meis1 protein, mouse; C508961:Tgfb1 protein, mouse