VPA and NAM treatment inhibits megakaryocyte progenitor proliferation.

<p>UCB-derived CD34+ cells were differentiated towards megakaryocytes for 11 days in the absence or presence of 100–200μM VPA, or 1-5mM NAM. (A) At all culture time points, trypan blue negative cells were counted. Data represent the fold expansion of megakaryocyte precursors during development. (B) At day 7 and 11, the percentage of apoptotic cells was determined by FACS. Data represent the percentage of Annexin V-positive cells, compared to the control. (C) Absolute numbers of CD61/CD42b positive megakaryocytes were calculated after 11 days of differentiation. Data are representative for 4 independent experiments. Error bars represent SEM, * p<0.05, ** p< 0.01.