Figure 6.

Notch2 signaling blockade increases hematopoietic stem cell and progenitor (HSPC) cell cycling. (A) Cell-cycling status of the marrow LSK cells and CD150⁺CD48⁻LSKs hematopoietic stem cells (HSCs) was determined by the proliferation marker Ki67 in conjunction with the DNA-specific dye 7-AAD in mice receiving 4 doses of control or Notch2 blocking antibody. One representative FACS profile of LSK cells, and the relative proportion of cells in G₀, G₁ and S-G₂/M phase of the cell cycle in LSK and HSC (bottom). Results are pooled from 2 experiments, and are presented as average±Standard Deviation (S.D.) (n=5/each group). (B) 1.5×10⁵ LK cells were co-cultured with confluent OP9-DLL4 or OP9-JAG1 cells in the presence of control (ctrl) or Notch2 blocking antibody (400 ng/mL) for four days before cell-cycling analysis on gated LK cells. One representative FACS profile of 3 similar experiments. Student t-test *P<0.05.