Figure 4.

DNA damage‐causing conditions induce the expression of GADD45A and mediate the differentiation in LT‐HSCs. (A): GADD45A expression after DNA damage‐causing regimens in KSL cells via quantitative real‐time polymerase chain reaction. Cells were harvested 4 hours post γ‐IR (2 Gy), or UV (1,200 J/m²), or after 5 hours Cisplatin (10 µg/ml) stimulation. The GADD45A expression was normalized to HPRT and relative to the unstimulated control (N = 3). (B): LT‐HSCs were stimulated with γ‐IR (2 Gy) and analyzed for their differentiation status via FACS on day 5 (N = 3). All data represented as mean + SD. **, p < .01; ***, p < .001. Abbreviations: Cis, cisplatin; G45A, GADD45A; HSPCs, hematopoietic stem and progenitor cells; IR, irradiation; LT‐HSC, long‐term repopulating hematopoietic stem cells; qPCR, quantitative polymerase chain reaction; SCF, stem cell factor; TPO, thrombopoietin; US, unstimulated; UV, ultraviolet.