APS From the Root of Angelica Sinesis Promotes Megakaryocytopoiesis and Thrombopoiesis Through PI3k/Akt Pathway

Abstract 4648

We have demonstrated the thrombopoietic effects of Chinese Medicine Dang Gui Bu Xue Tong (DBT), a formula composed of Radix Angelicae Sinensis and Radix Astragali in a thrombocypenic mouse model (Yang M et al, J Ethnopharm 2009). In this study, we further test the effect of polysaccharide (APS) from the root of Radix Angelicae Sinensis (APS) in in-vivo thrombopoiesis and in in-vitro megakaryocytopoiesis. A myelosuppression and thrombocytopenia mouse model was treated with APS (10 mg/kg/day), thrombopoietin (TPO) and saline as control. Peripheral blood cells from APS, TPO and vehicle-treated samples were then counted in different time-points. Using the colony-forming unit (CFU) assays, we determined the effects of APS on the hematopoietic stem/progenitor cells and megakaryocytic lineages. Analyses of Annexin V, Caspase-3, and Mitochondrial Membrane Potential were also conducted in megakaryocytic cell line M-07e. Lastly, the effects of APS on cells treated with Ly294002, a Phosphatidylinositol 3-Kinse inhibitor and the effect of APS on the phosphorylation of AKT were further studied in megakaryocytic cells. Our results showed that APS significantly enhanced the platelets and other blood cells recovery and CFU formation in this model. Morphological examination of bone marrows showed that APS treatment significantly increased the recovery of the megakaryocytic series and other hematopoietic progenitor cells. We observed the antiapoptotic effects of APS on M-07e cells. Addition of Ly294002 alone increases the percentage of cells undergoing apoptosis. In contrast, additional of APS to Ly294002-treated cells reversed the percentage of cells undergoing apoptosis. Furthermore, addition of APS significantly increased the phosphorylation of AKT. Our studies demonstrate that APS promotes platelet recovery in the mouse model and has anti-apoptosis effect in megakaryocytic cells. This effect is likely to be mediated by the PI3K/AKT pathway.