PB1989 SHORT‐TERM APPLICATION OF CAFFEIC ACID SPECIFICALLY PROMOTES EXPANSION OF HEMATOPOIETIC STEM CELLS

Abstract

Background:Caffeic acid (CFA) is a commonly used medicine in China for treatment of various causes of thrombocytopenia and leukocytopenia, but the mechanism is unclear.Aims:To investigate the effect of CFA on umbilical cord blood hematopoietic stem cells (UCB–HSCs) in vitro and explore the differentiated effect of CFA on cell expansion and differentiation in various tissues in vivo.Methods:CD34+ HSCs were isolated from cord blood and cultured for expansion. After 7 days’ culture with CFA, the total cell number and proportion of CD34+ cells were detected. Differentiation ability was analyzed by colony formation assay and megakaryocytes inducing assay before and after expansion. Additionally, CD‐1 mice were administered with CFA or vehicle for 14 days and BrdU injection started from day 7. Blood cell count was examined every 3 days. The proportion in bone marrow nucleated cells and BrdU insertion rate of HSCs were detected by flow cytometry. Besides, the percentage and BrdU insertion rate of Lgr5+ stem cells in intestinal mucosa, Sca‐1+ cells in lung and CK‐18+ epithelial cells in kidney were also analyzed.Results:In HSC expansion tests, the mean number (4.40∗10^5/well) and proportion (60%) of CD34+ cell in CFA groups were significantly higher than controls (4.00∗10^5/well; 48%). In HSC colony formation assay and megakaryocytes inducing assay, there were no significant difference between CFA groups and control. In vivo, the mean proportion (1.59%) and BrdU insertion rate (5.18%) of HSCs in CFA groups were higher than control (0.65% and 2.24%). No statistical differences were observed in other tissues.Summary/Conclusion:CFA can promote expansion of UCB–HSCs. Administration of CFA for 14 days specifically increased the proportion and DNA synthesis rate of bone marrow HSC in mice.image