Pharmacologic inhibition of MAPK14/p38 enhances the HSPC activity of cultured CB CD34⁺ cells. CB CD34⁺ cells (70 000-100 000 cells per well) were cultured in STF medium supplemented by the specified MAPK14/p38 inhibitors or vehicle (DMSO) during 5 days and were then analyzed by FACS or transplanted to sublethally irradiated NSG mice. (A) Time course expression analysis of total p38 (t-P38) and phosphorylated p38 (p-p38). Actin expression was used as loading control (act). D indicates days. (B) FACS analysis for CD34 and CD90 expression. (C) Numbers of CD34⁺90⁺ cells (data from a representative experiment with 3 independent replicates). Error bars represent SEM (D) Percentage of human (CD45⁺) cells in peripheral blood of NSG recipients (3-4 animals per group) at 6, 10, and 16 weeks after transplantation. (E) Lympho-myeloid potential assessed by FACS analysis of human CD19 (B-lymphoid cells) and CD33/CD15 (myeloid cells) in bone marrow of NSG recipient mice, 17 weeks after transplantation. Each plot represents an animal from the experiment presented in panel D. Numbers indicate the percentage of positive cells in whole bone marrow. (F) ROS staining (DCFDA probe) assessed by FACS and presented as fluorescence mean intensity (fmi) in CD34⁺ cells. Pooled data from 3 independent experiments. Error bars represent SEM. D indicates DMSO; SB, SB203580; Vx, Vx702; B, BIRB796; and Ly, Ly2228820.