Enhanced hematopoietic recovery in Ndn-deficient mice after 5-FU treatment. (A) Kinetics of hematopoietic recovery in Ndn-deficient mice after myelosuppression with a single dose of 5-FU. Mice were intravenously injected with 5-FU (200 mg/kg), and the number of white blood cells (WBC; top panel) and platelets (bottom panel) were counted at the indicated time. Data shown are representative from 2 independent experiments that gave similar results (n = 10). Error bars represent SD. *P < .05. **P < .01. (B-D) Transient enhanced proliferation of Ndn^+m/−p HSCs after 5-FU treatment. Mice were intravenously injected with 5-FU (200 mg/kg) and BM KSL cells analyzed at day 15 and day 28 after 5-FU. (B) Representative FACS profiles of BM KSL cells from Ndn^+/+ and Ndn^+m/−p mice at day15 after 5-FU injection. (C) The absolute number of KSL cells at day 15 (n = 3). *P = .013. (D) The absolute number of KSL cells at day 28 (n = 3). (E-F) Increased BrdU incorporation (days 7-10) in Ndn^+m/−p HSCs after 5-FU treatment. Mice were intravenously injected with 5-FU (200 mg/kg); and 3 days before analysis, mice received an intraperitoneal injection of BrdU (1 mg/6 g of mouse weight) after which BrdU was included in the drinking water (1 mg/mL). BrdU incorporation in BM KSL cells was evaluated using anti-BrdU antibodies. (E) Representative FACS profile of KSL cells at day 10 after 5-FU injection. (F) Mean percentage ± SD of KSL cells in G₀ (BrdU⁻) at day10 after 5-FU injection (n = 3). *P = .038.