Anna Elizabeth Eastman

All Publications

• Resolving Cell Cycle Speed in One Snapshot with a Live-Cell Fluorescent Reporter. Cell reports Eastman, A. E., Chen, X., Hu, X., Hartman, A. A., Pearlman Morales, A. M., Yang, C., Lu, J., Kueh, H. Y., Guo, S. 2020; 31 (12): 107804

  Abstract

  Cell proliferation changes concomitantly with fate transitions during reprogramming, differentiation, regeneration, and oncogenesis. Methods to resolve cell cycle length heterogeneity in real time are currently lacking. Here, we describe a genetically encoded fluorescent reporter that captures live-cell cycle speed using a single measurement. This reporter is based on the color-changing fluorescent timer (FT) protein, which emits blue fluorescence when newly synthesized before maturing into a red fluorescent protein. We generated a mouse strain expressing an H2B-FT fusion reporter from a universally active locus and demonstrate that faster cycling cells can be distinguished from slower cycling ones on the basis of the intracellular fluorescence ratio between the FT's blue and red states. Using this reporter, we reveal the native cell cycle speed distributions of fresh hematopoietic cells and demonstrate its utility in analyzing cell proliferation in solid tissues. This system is broadly applicable for dissecting functional heterogeneity associated with cell cycle dynamics in complex tissues.

  View details for DOI 10.1016/j.celrep.2020.107804

  View details for PubMedID 32579930

  View details for PubMedCentralID PMC7418154

• Purification and characterization of human neural stem and progenitor cells. Cell Liu, D. D., He, J. Q., Sinha, R., Eastman, A. E., Toland, A. M., Morri, M., Neff, N. F., Vogel, H., Uchida, N., Weissman, I. L. 2023; 186 (6): 1179

  Abstract

  The human brain undergoes rapid development at mid-gestation from a pool of neural stem and progenitor cells (NSPCs) that give rise to the neurons, oligodendrocytes, and astrocytes of the mature brain. Functional study of these cell types has been hampered by a lack of precise purification methods. We describe a method for prospectively isolating ten distinct NSPC types from the developing human brain using cell-surface markers. CD24-THY1-/lo cells were enriched for radial glia, which robustly engrafted and differentiated into all three neural lineages in the mouse brain. THY1hi cells marked unipotent oligodendrocyte precursors committed to an oligodendroglial fate, and CD24+THY1-/lo cells marked committed excitatory and inhibitory neuronal lineages. Notably, we identify and functionally characterize a transcriptomically distinct THY1hiEGFRhiPDGFRA- bipotent glial progenitor cell (GPC), which is lineage-restricted to astrocytes and oligodendrocytes, but not to neurons. Our study provides a framework for the functional study of distinct cell types in human neurodevelopment.

  View details for DOI 10.1016/j.cell.2023.02.017

  View details for PubMedID 36931245

• The palette of techniques for cell cycle analysis. FEBS letters Eastman, A. E., Guo, S. 2020

  Abstract

  The cell division cycle is the generational period of cellular growth and propagation. Cell cycle progression needs to be highly regulated to preserve genomic fidelity while increasing cell number. In multicellular organisms, the cell cycle must also coordinate with cell fate specification during development and tissue homeostasis. Altered cell cycle dynamics play a central role also in a number of pathophysiological processes. Thus, extensive effort has been made to define the biochemical machineries that execute the cell cycle and their regulation, as well as implementing more sensitive and accurate cell cycle measurements. Here, we review the available techniques for cell cycle analysis, revisiting the assumptions behind conventional population-based measurements and discussing new tools to better address cell cycle heterogeneity in the single-cell era. We weigh the strengths, weaknesses, and trade-offs of methods designed to measure temporal aspects of the cell cycle. Finally, we discuss emerging techniques for capturing cell cycle speed at single-cell resolution in live animals.

  View details for DOI 10.1002/1873-3468.13842

  View details for PubMedID 32441778