CH02 Peptide Promotes CD34+ Umbilical Cord Blood Hematopoietic Stem Cells Ex Vivo Expansion

Abstract:Background: Umbilical cord blood (UCB) has been clinically used for human hematopoietic stem cells (HSCs) transplantation. However, limited numbers of the functional UCB-HSCs from single cord blood restricts its application in adults, while most of the strategies for stem cells expansion in vitro are either inefficient or costly. To overcome these obstacles, we evaluated the potential role of our newly identified CH02 peptide in ex vivo culture expansion of CD34+ UCB-HSCs. Methods: Enriched human CD34+ progenitor/stem cells populations were cultured in serum-free medium supplemented with different cytokines combinations for 8 days. These cytokines combinations included various concentration of CH02 peptide or the FLT3 ligand, with a cocktail of several growth factors such as IL-6, SCF and TPO. In addition, the global gene expression profile of the CD34+ cells cultured under different conditions were monitored through RNA-seq experiments. Furthermore, the expanded CD34+ cells were topically transplanted into the dorsal wounds of diabetic mice, and the wound closure was observed to evaluate the pro-repair ability of CH02-cultured CD34+ cells.Results: We herein report that the combination of CH02 peptide and other cytokines under the serum-free medium can effectively expand the CD34+ HSCs into 12-fold within 7 days while maintaining their stem cell properties. Moreover, CH02 peptide increased the anti-inflammatory and growth-promoting capacity of CD34+ cells, and thus accelerating wound healing of diabetic mice via promoting the anti-inflammatory and inhibiting the inflammatory factors.Conclusions: Together, our CH02 peptide demonstrated promising potentials to improve HSCs expansion for clinical application.