Cell cycle and differentiation of Sca-1⁺ and Sca-1⁻ hematopoietic stem and progenitor cells

Abstract

Hematopoietic stem and progenitor cells (HSPCs) are crucial for lifelong blood cell production. We analyzed the cell cycle and cell production rate in HSPCs in murine hematopoiesis. The labeling of DNA-synthesizing cells by two thymidine analogues, optimized for in-vivo use, enabled determination of the cell cycle flow rate into G2-phase, the duration of S-phase and the average cell cycle time in Sca-1 and Sca-1 HSPCs. Determination of cells with 2n DNA content labeled in preceding S-phase was then used to establish the cell flow rates in G1-phase. Our measurements revealed a significant difference in how Sca-1 and Sca-1 myeloid progenitors self-renew and differentiate. Division of the Sca-1 progenitors led to loss of the Sca-1 marker in about half of newly produced cells, corresponding to asymmetric cell division. Sca-1 cells arising from cell division entered a new round of the cell cycle, corresponding to symmetric self-renewing cell division. The novel data also enabled the estimation of the cell production rates in Sca-1 and in three subtypes of Sca-1 HSPCs and revealed Sca-1 negative cells as the major amplification stage in the blood cell development.

Assessment of the in Vitro Antimelanoma Potential of Lippia microphylla Cham (Verbenaceae) Essential Oil

“…With the propidium iodide marker, it is possible to distinguish between cells present in the G0/G1 phase, which are diploid (2n) and not dividing, cells in the process of cell division that initiate the duplication of their genetic material in the S phase (>2n), and cells that with fully duplicated genetic material in the G2/M (4n) phase [48,49] …”

“…Cell line IC 50 [c] [μg/mL] SI [b] HCT-116 100.1 � 1.12 0.5 the S phase (> 2n), and cells that with fully duplicated genetic material in the G2/M (4n) phase. [48,49] The results obtained revealed a significant increase in cells in the sub-G1 population when EO-LM was incubated at 33 μg/ mL (15.36 � 1.49 %; p < 0.0001) or 66 μg/mL (22.08 � 0.27 %; p < 0.0001) as compared to the control group (Figure 2). The G0/G1 phase was also increased to 38.05 � 1.8 % (p < 0.01) and 53.20 � 0.8 % (p < 0.0001), when SK-MEL-28 cells were treated with 33 and 66 μg/mL, respectively (Figure 2).…”

Functions and regulatory mechanisms of resting hematopoietic stem cells: a promising targeted therapeutic strategy

“…Thy-1 low Sca-1 + Lineage-c-kit + cells in aging mice reportedly include CD48 + and/or CD150 cells, which are unable to perform recombination [ 17 ]. There is also a significant difference in the self-renewal and differentiation of HSCs in Sca-1+ and Sca-1- [ 18 ], and this research provides a method to test the active state of HSCs. Cell sorting is indispensable when studying the functional activities of HSCs, and technological progress has made it possible to develop targeted therapies.…”