Figure 2: Characterization of HSPC in the bone marrow and spleen of Thbd-deficient mice.

(A) Bone marrow histology of Thbd^DEL mice. Formalin-fixed sections of femurs of Thbd, hematoxylin-eosin stain. (B) Reduced BM cellularity in Thbd^DEL mice (n=8/group). (C,D). Frequency and absolute numbers of HSPC (C) and bone marrow B cells (D) in control (open bars; n=9) and Thbd^DEL mice (closed bars; n=8). LT: LSK-CD34⁻CD135⁺; ST: LSK-CD34⁺CD135⁻; MPP: LSK-CD34⁺CD135⁺; CLP: Lin⁻Sca-1^loc-Kit^loIL7Rα⁺; CMP: Lin⁻Sca-1⁻c-Kit⁺CD34⁺CD16/32⁻; GMP: Lin⁻Sca-1⁻c-Kit⁺CD34⁺CD16/32⁺; MEP, Lin⁻Sca-1⁻c-Kit⁺CD34⁻CD16/32⁻. (E) Cytometry histograms showing normal EPCR expression in LT-HSC and SLAM-HSC of wildtype and Thbd^DEL mice. Data shown are representative of 4 animals/group. (F) Increased abundance of HSPC (left) and hematopoietic activity (Colony-forming-units Granulocyte-Monocyte) in the spleen of wildtype (open bars) and Thbd^DEL mice (closed bars; n=10/group). (G) Cytometry plots of CD48/CD150 expression on LSK cells of wildtype and Thbd^DEL mice. CD48^NEGCD150^POS SLAM-HSC were then analyzed for CD34/CD135 expression (n=5/group). (H) Flow cytometric analysis of CD34/CD135^NEG LT-HSC for expression of the proliferation marker Ki67 and binding of annexin V to cell surface-associated phosphatidylserine as a marker of apoptosis (n=5/group). All numerical data are represented as mean±st.dev. Two-tailed, unpaired Student’s t-test was performed to determine significance. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.