Exogenous C/EBPα restores granulopoiesis relative to monopoiesis in Runx1-deleted marrow cells. (A) Marrow mononuclear cells isolated from Runx1(f/f);Mx1-Cre mice exposed to pIpC and subsequently to 5-FU were transduced with RUNX1-ER or with the pBabePuro vector, selected with puromycin, and then placed in liquid culture with IL-3, IL-6, and SCF with or without 4HT. Total cellular proteins collected 2 days later were subjected to Western blot analysis with the use of C/EBPα, PU.1, ERα, or β-actin Abs. (B) Marrow mononuclear cells isolated from Runx1(f/f);Mx1-Cre mice exposed to pIpC and subsequently to 5-FU were transduced with C/EBPα-ER, selected with puromycin, and then plated in methylcellulose with IL-3, IL-6, and SCF with or without 1.0μM or 0.03μM E2. The proportion of CFU-Gs or CFU-Ms among these myeloid CFUs is shown (left and center panels; mean and SE from 3 determinations). Similar analysis was conducted after transduction with pBabePuro and culture with or without 1.0 μM E2 (right panel; mean and SE from 3 determinations).
