Asymmetry in skeletal distribution of mouse hematopoietic stem cell clones and their equilibration by mobilizing cytokines

Abstract

Upon transplant, functional HSC clones preferentially expand in certain skeletal locations, exhibiting only limited migration toward other niches.

Epigenetic Memory Underlies Cell-Autonomous Heterogeneous Behavior of Hematopoietic Stem Cells

“…HSC were found to infrequently (~1/110 HSC per day) generate downstream progeny producing blood cells while maintaining the HSC pool. Our data are also consistent with recent data in mouse (Verovskaya et al, 2014) and human (Biasco et al, 2016), that the majority of the hematopoietic population is sustained by a few major HSC clones despite the existence of smaller clones. This is in contrast to the report by Sun et al (2014b), which suggests that murine hematopoiesis is maintained by thousands of progenitor clones rather than HSCs.…”

A Lentiviral Fluorescent Genetic Barcoding System for Flow Cytometry-Based Multiplex Tracking

“…This design would allow for flow cytometric tracking of color-coded populations as well as next generation sequencing-based assessment of clonality in multiplexed samples, which may be especially powerful when working with HSCs and leukemic stem cells. [2][3][4]33 To this end, we established color coding conditions for murine HSCs and human CB derived CD34 + HSPC and evaluated the in vivo color code distribution in different BM subpopulations at the end of the observation period (Figures 5 and 6). To neglect cell type-specific differences in CSF promoter activity as well as potential variations in expression intensity due to the influence of the activation status of the (e.g., T) cells, gates were first set based on surface marker expression before analyzing color-coded populations therein.…”

“…While gammaretroviral or lentiviral delivery of readily detectable reporters has initially proven valuable for enrichment and tracking of transduced populations, viral integration site analysis and retroviral barcoding have further improved clonal resolutions. [1][2][3][4][5][6][7] The power of integration site analysis and DNA barcoding lies in parallel cell fate tracking, which opens up numerous experimental opportunities including in vivo applications in a reduced number of mice enabling decreased variability and improved efficiencies. 8 Application of such tracking and fate mapping approaches have for example been extensively and elegantly exploited in the context of studies in the hematopoietic system both in vivo and in vitro.…”

“…8 Application of such tracking and fate mapping approaches have for example been extensively and elegantly exploited in the context of studies in the hematopoietic system both in vivo and in vitro. [2][3][4]9,10 Despite these opportunities, molecular multiplexing generally imposes a substantial delay between sample acquisition and data mining due to the requirement for PCR amplification steps, next generation sequencing, and bioinformatics analyses. 8 For accelerated multiplex characterization of a smaller number of cell populations as required for the comparison of culture conditions, drug treatment responses, or replicate experiments in the same mouse or culture well, a real-time readout system would be desirable.…”

Aging of the hematopoietic stem cells niche

“…To clarify these discrepancies, a barcoding technique was used to identify the distribution of individual transplanted HSC clones. Barcoded aged and young transplanted HSCs present a skewed distribution that did not show equilibration even by 11 months after transplantation [90]. Mobilization induced through an one-time administration of G-CSF to mice following either aged or young transplanted HSCs sufficiently equilibrated the skewed distribution of transplanted HSC clones indicating that cell kinetics upon mobilization did not differ between aged and young HSCs.…”