The Effect of Platelet Lysate on Expansion and Differentiation Megakaryocyte Progenitor Cells from Cord Blood CD34+ enriched Cells

Background: Umbilical cord blood hematopoietic stem cells (UCB-HSCs) are an attractive source for transplantation. The generation of megakaryocyte-committed cells could lead to shorten period of thrombocytopenia after HSCs transplantation. Platelet lysate (PL) unlike fetal bovine serum (FBS) can prevent immune problems as well as avert transmission of certain diseases to the recipient. In this study, the authors aimed to assess the effect of PL on UCB CD34(+) cells expansion and megakaryocyte differentiation. Materials and Methods: In this experimental study, PL prepared and the subsequent isolation of UCB CD34(+) cells were done by magnetic cell sorting. The isolated cells were cultivated in Iscove's Modified Dulbecco's medium (IMDM) supplemented with PL or FBS. Cell expansion was evaluated using Trypan blue. Furthermore, Flow cytometry using monoclonal antibodies (CD41-FITC and CD42b-PE) and the expression of specific genes including GATA1, GATA2, FLI1, NFE2, and RUNX1 via real-time PCR were performed to evaluate the megakaryocyte differentiation. Results: The results showed that PL insignificantly enhanced UCB CD34+ cell expansion (32.83 +/- 8.47 fold in FBS and 41.67 +/- 10.31 fold in PL containing media). Besides, flow cytometry results showed that expression of CD41 was increased markedly (37.81 +/- 4.78 fold in FBS and 45.78 +/- 7.37 in PL containing media, P-value <0.05) but the elevation of CD42b (10.53 +/- 2.13 and 13.20 +/- 2.06 in FBS and PL containing media, respectively) was not significant (P-value = 0.051). The results of real-time PCR demonstrated a notable increase in GATA binding protein 1 (1.58, P-value <0.01), GATA binding protein 2 (2.45, P-value <0.001), RUNX family transcription factor 1 (1.60, P-value <0.01), Fli-1 proto-oncogene ( 1.87, P-value <0.001) in PL supplemented media, however, the increase of Nuclear Factor-Erythroid 2 gene expression was not significant in PL supplemented media (Pvalue = 0.11). Conclusion: PL improved UCB CD34(+) cells expansion and megakaryocyte differentiation compared to FBS.