Abstract

 Background and Objectives

 Cord blood CD133⁺ cells are able to maintain long-term hematopoiesis and to differentiate to different hematopoietic lineages. CXCR4 overexpression is involved in successful transplantation of hematopoietic stem cells in the bone marrow. Platelet micro particles (PMP) contain CXCR4 markers and are able to transfer them into hematopoietic stem cells. Therefore, considering the importance of CD133⁺ cells as primitive HSCs, the effect of platelet micro particles on the expression levels of CXCR4 and CD34 markers in these cells was examined.

 Materials and Methods

 In this experimental study, cord blood CD133⁺ cells were isolated by MACS. Isolated cells were cultured into three groups one as control without adding PMP and the other two groups with PMP with concentrations of 5 and 10 μg/mL. The cells were cultured for five days in stem span medium. Expression of CXCR4 surface marker was analyzed by flow cytometery the total cell number was counted by hemocytometer and colony forming units (CFU) were measured by colony assay.

 Results

 Fold increase of CD34⁺ and CXCR4⁺ cells in the control group and in the presence of 5 and 10 µ g/mL of PMP were 52.6 ± 4.16, 64.2 ± 6.91, and 67.2 ± 6.76, respectively (p= 0.047). CXCR4⁺ cell percentage in the presence of 10 µ g/mL PMP compared to control cells (63.8 ± 6.4) was 72.8 ± 4 (p= 0.049).

 Conclusions

 Exposure of CD133⁺ cells isolated from cord blood to PMP with 10 μg/mL concentration increased the expression of CXCR4 surface marker significantly.