Page 146 - 2020_02-Haematologica-web

V. Caraffini et al.
treated with a granulocyte-macrophage colony-stimulat- ing factor (GM-CSF)/flt-3 ligand (FL)/stem cell factor (SCF)/tumor necrosis factor-α (TNFα) cytokine mix to induce myelomonocytic differentiation.29 Five days later,
the expression of myelomonocytic surface markers CD11b and CD14 was assessed. In these experiments, myelomonocytic differentiation was significantly increased in HSPC transduced with the RKIP shRNA
A
B
CD
spleens from Mx1-Cre/Nras/Rkip+/+ and Mx1-Cre/Nras/Rkip-/- mice as well as bar graphs of spleen lengths and weights, showing splenomegaly in animals with Rkip deletion. (B) Representative flow cytometric plots showing an increase in the percent- age of CD11b+ and CD11b+ Ly6G+ myelomonocytic cells in peripheral blood (PB), bone marrow (BM) and spleen (SP) of Mx1-Cre/Nras/Rkip-/- mice when these were compared to Nras/Rkip+/+ animals as well as when compared to Mx1-Cre/Nras/Rkip+/+ littermates. (C) Peripheral blood counts demonstrate an increased number of white blood cells (WBC) in Mx1-Cre/Nras/Rkip-/- mice. (D) The leukocytosis in Mx1-Cre/Nras/Rkip-/- mice is caused by an increased num- ber of myelomonocytic cells (MMC), as shown in the representative PB smear and as shown in the flow cyto- metric analyses shown above. Graphs show the average ± Standard Deviation. Statistical significance was calculated by Student’s t-test. RKIP: RAF kinase inhibitor protein.
Figure 4. Deletion of Rkip aggravates myeloproliferation and myeloprolif- erative disease (MPD) development in Nras-mutated mice. An Nras driv- en mouse model of myeloprolifera- tion (Mx1-Cre/Nras) was used to study the effects of Rkip-/- on Ras-dri- ven myeloproliferation and MPD development. Mice were electively killed at an age of six months after the first pIpC injection, Mx1-Cre/Nras/Rkip-/- mice (n=3) were compared to control mice (Mx1- Cre/Nras/Rkip+/+; n=3) as well as to mice without Mx1-Cre (Nras/Rkip+/+; n=4). (A) Representative images of
Nras/Rkip+/+,
380
haematologica | 2020; 105(2)