Skip to main content
. 2021 Mar 18;296:100563. doi: 10.1016/j.jbc.2021.100563

Figure 4.

Figure 4

Codeletion of Atm and p38α induces HSC loss and defective transplantation capacity.A–C, immunocytochemical analysis of 53BP1 and gamma-H2AX in Atm+/+ or AtmΔ/Δ LT-HSCs recovered from BMT recipients. Cytospin samples of sorted cells were stained with anti-53BP1 (red) and gamma-H2AX (green) antibodies combined with DAPI (blue) (A). Quantification of 53BP1 (B) and gamma-H2AX foci (C) (means ± SD, n = 27–35). D, experimental design used to test effects of p38α loss in AtmΔ/Δ mice. E and F, analysis of PB differentiation status (B220+ B cells [B], CD4+ T cells [CD4], CD8+ T cells [CD8], Mac-1+Gr-1hi granulocytes [Gra], or Mac-1+Gr-1lo macrophages [Mac]) (means ± SD, n = 5) (E), and frequencies of BM HSPCs including CLPs (common lymphoid progenitors; Lin−IL7Rα+Flt3+Sca-1/c-Kitlo), MEPs (megakaryocyte-erythroid progenitors; Lin−IL7Rα−Sca-1−c-Kit+CD16/32−CD34−), GMPs (granulocyte-monocyte progenitors; Lin−IL7Rα−Sca-1−c-Kit+CD16/32+CD34+), CMPs (common myeloid progenitors; Lin−IL7Rα−Sca-1−c-Kit+CD16/32−CD34+), MPPs (CD34+Flt3+LSK), ST-HSCs (CD34+Flt3−LSK), or LT-HSCs (CD34−Flt3−LSK) (means ± SD, n = 5) (F) in mice of indicated genotypes. G–I, chimerism of donor-derived PB cells in primary (G), secondary (H), and tertiary (I) BMT of HSCs of indicated genotypes (means ± SE, n = 6). J and K, chimerism of donor-derived BM cell, including LT-HSCs (CD34−Flt3−LSK), ST-HSCs (CD34+Flt3−LSK), MPPs (CD34+Flt3+LSK), LKS− (Lin−c-Kit+Sca-1−), Lin+ (lineage marker positive), and PI− (propidium iodide negative) cells from primary (J) and secondary (K) recipients, 4 months after BMT (means ± SE, n = 5–6). All data are derived from a single experiment. ∗p < 0.05 and ∗∗p < 0.01. Atm, ataxia–telangiectasia mutated; BM, bone marrow; BMT, bone marrow transplantation; 53BP1, tumor suppressor p53-binding protein 1; DAPI, 4′,6-diamidino-2-phenylindole; HSPC, hematopoietic stem/progenitor cell; LT-HSC, long-term hematopoietic stem cell; MPP, multipotent progenitor cell; PB, peripheral blood; ST-HSC, short-term hematopoietic stem cell; TAM, tamoxifen.