The effect of human platelet lysate on self-renewal and homing potential of peripheral blood -derived hematopoietic stem cells

Hematopoietic stem and progenitor cells (HSPCs) hold significant promise for various diseases and gene therapy, highlighting the need for improved in vitro expansion while maintaining their properties. Efficient HSPC expansion requires an environment that preserves self-renewal and homing capabilities. Human Platelet Lysates (HPL) contain bioactive molecules and growth factors that may enhance HSPC functionality. This study investigates the effects of HPL on peripheral blood HSPC proliferation, self-renewal capacity, and homing. We observed that HPL significantly promoted HSPC proliferation, resulting in a 1.7-fold increase in final cell count and reduced doubling time, without affecting colony-forming capacity. Flow cytometry analysis revealed no significant changes in the percentages of CD34⁺, CD34^-CD38⁺, CD34⁺CD38⁺, and CD34⁺CD38^- cells, though CXCR4 marker expression was notably higher in the HPL-treated group. Furthermore, real-time analysis of self-renewal genes (GFI1, HOXB4, and TAL1) indicated a significant increase in GFI1 expression, while HOXB4 and TAL1 remained unchanged. Among homing-related genes (CXCR4, VLA-4, and LFA-1), CXCR4 expression increased significantly, while VLA-4 and LFA-1 levels showed no significant alterations. These findings suggest that HPL enhances HSPC proliferation while preserving their self-renewal and homing abilities, providing a promising approach for optimizing HSPC culture conditions for both research and clinical use.