Human Mesenchymal Stem / Stromal Cells (hMSCs) treated with Eltrombopag show increase of the hematopoietic supporting ability

Eltrombopag (EP) is a small molecule that acts on hematopoietic cells and megakaryocytes to stimulate the hematopoiesis. Mesenchymal stem/stromal cells (MSCs) are key hematopoietic niche regulators. In the current work we aimed to assess if EP exert any effect on MSCs function, especially on their hematopoietic-supporting ability, and if so, what are the changes (including transcriptomic) induced in MSCs after EP treatment. For this purpose, MSCs were isolated from 12 healthy donors and treated with 15 uM and 50 uM of EP for 24 hours. The toxicity of the drug on MSCs and their differentiation ability were analyzed, as well as the transcriptomic profile, ROS and DNA damage and finally the changes induced in the clonogenic capacity of HSC. We observed that EP acts on MSCs decreasing their adipogenic differentiation, increasing the expression of genes involved in hypoxia and other pathways and enhancing their ability to support hematopoiesis. We used high density oligo microarrays (Affymetrix Clariom_S_Human) to obtain the global programme of gene expression underlying the effect of the Eltrombopag (EP) and Thrombopoietin (TPO) in human MSCs (derived from bone marrow) and identify the genes activity. Mesenchymal Stem / Stromal Cells (MSCs) isolated from human bone marrow were treated with EP at concentrations 15 uM and 50 uM for 24 hours and then RNA extraction and hybridization on Affymetrix genome-wide expression microarrays (Clariom S) was performed. The aim was to evaluate the toxicity of the drug EP in two different concentrations and the differentiation ability of the mesenchymal stem cells treated. To achieve this we analyzed the genome-wide expression profile of MSC samples prepared from four independent donors (i.e., using four biological replicates 1,2,3,4) and studied in four treatment conditions: (i) MSCs control with no drug addition, 0 micromolar; (ii) MSCs with Eltrombopag at concentration 15 micromolar: Eltrombopag_15uM; (iii) MSCs with Eltrombopag concentration 50 micromolar: Eltrombopag_50uM; and (iv) MSCs treated with Thrombopoietin.