Figure 1.

Chrysin promoted in vitro expansion of primitive human hematopoietic stem and progenitor cells. (A) The percentages and absolute numbers of CD34⁺CD49f⁺ cells after 7 days in cultures supplemented with concentration gradient (0.5, 1, 2.5, 5, and 10 µM) of C2968 (n = 5). The concentration of SR1 was 1 µM. (B) Quantification of total input and output CD34⁺ cells in culture (n = 7; n = 6 for uncultured cells). UCB CD34⁺ cells (1 × 10⁴) were seeded in the beginning of the culture. (C) The percentages and absolute numbers of CD34⁺CD38⁻, CD34⁺CD38⁻CD49f⁺, and CD34⁺CD38⁻CD45RA⁻CD90⁺ cells derived from uncultured CD34⁺ cells or after 7 days in cultures supplemented with Con [dimethyl sulfoxide (DMSO) 0.01%], SR1 (1 µM), and C2968 (2.5 µM) (n = 7; n = 6 for uncultured cells). All data represent the means ± SD. Compared with uncultured group unless specified, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001 and ns, no significance by two-tailed unpaired t-test. ○, □, Δ and ◊ represent a single data point in Uncultured (Uncult.), Con, SR1 and C2968 groups respectively. (D) Representative FACS profiles of CD34⁺CD38⁻, CD34⁺CD38⁻CD49f⁺, and CD34⁺CD38⁻CD45RA⁻CD90⁺ populations derived from total live cells in uncultured and cultured CD34⁺ cells.