Lenalidomide rescued LPS-induced MDS phenotypes in mDia1 heterozygous and knockout mice. (A) Kaplan-Meier survival curve of mDia1 heterozygous mice pretreated with lenalidomide (10 mg/kg per day for 5 days) followed by a lethal dose of LPS (30 µg/g). Data were from 3 independent experiments. Mice used were 6-8 weeks old. (B-C) Real-time PCR analysis of TNFα (B) and CD14 (C) mRNA levels in Gr1/Mac1 double-positive bone marrow cells from mDia1 heterozygous mice (6-8 weeks old) treated with dimethylsulfoxide (DMSO), LPS (2 µg/mL) alone, or LPS plus the indicated dosage of lenalidomide. (D) Neutrophil and platelet counts of indicated mice treated with chronic low-dose LPS (10 µg/g every 20 days) plus lenalidomide or vehicle control for 4 months. N = 5 in each group except mDia1 knockout mice treated with LPS and lenalidomide (N = 4). Mice were 6-8 weeks old at the time of first injection. (E) H&E stains of bone marrow sections of indicated mice from panel D. Arrows indicate dysplastic granulocytes. Scale bars represent 50 μm.