Platelet growth factors suppress ex vivo expansion and enhance differentiation of umbilical cord blood CD133⁺ stem cells to megakaryocyte progenitor cells

Abstract

Background and objectives: Umbilical cord blood (UCB) is a rich source of hematopoietic cells. Here, for the first time, we surveyed the effects of different concentrations of platelet growth factors and cytokine cocktail (CC) on the expansion and differentiation of UCB CD133⁺ stem cells into megakaryocyte progenitors.

Materials and methods: UCB CD133⁺ cells were separated by magnetic cell sorting and cultured in different concentrations of platelet growth factors in combination with a CC containing interleukins 3 and 6, stem cell factor, and thrombopoietin. Cell expansion and differentiation were assessed using mononuclear cell count and flow cytometry.

Results: The results show that either activated platelet-rich plasma or the platelet supernatant, when added in the first day of culture, significantly suppress the expansion of CD133⁺ cells after 7 days in culture (p < 0.05). By contrast, the expression of CD41, CD61, and CD42b markers in the presence of all platelet growth factors increased compared with that of the control (p < 0.05).

Conclusion: Taken together, platelet growth factors in the presence of CC suppress ex vivo expansion of UCB CD133⁺ cells and enhance their differentiation into megakaryocytic progenitor cells in a dose- and time-dependent manner.

Keywords::

• Umbilical cord blood
• CD133⁺ cells
• megakaryocyte progenitor cells
• platelet growth factors

Acknowledgements

This study was supported by a grant from the research center of Iranian Blood Transfusion Organization (grant no. 25312). We are thankful to the Department of Gynecology and Obstetrics of Milad Hospital (Tehran, Iran) for the provision of UCB sample. We thank Departments of Flow Cytometry and Apheresis at Iranian Blood Transfusion Organization for their technical assistance in cell analysis and PRP preparation. We are also grateful to Dr Mehrdad Pedram (Department of Medical Genetics, Tehran University of Medical Science) for his careful editing of the manuscript and helpful comments.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.