Effects Of Angelica Polysaccharides On Adhesion Molecules Expression And Adhesive Function In Murine Hematopoietic Cells

There are thousands of years that Angelica is an important Chinese crude drug to nourish the blood and promote blood flow. Modern empirical studies have showed that the chemical composition of angelica is very complex, and Angelica polysaccharides (APS) is one of the main chemical composition in it. The past researches discovered that APS could obviously promote the proliferation and differentiation of BFU-E, CFU-E, CFU-GM and CFU-MK in health and anaemic mice. APS also could promote the proliferation and differentiation of BFU-E, CFU-E, CFU-GM and CFU-Mix in the human being. APS could mobilize hematopoietic stem progenitor cells from bone marrow into peripheral blood. And APS in combination with rhG-CSF may cooperate with each other. The hematopoietic stem progenitor cells mobilized by APS can reconstruct long-term hematopoiesis in hematopoiesis failure mice.The cytokine,granulocyte colony-stimulating factor (rhG-CSF) in particular,is much more frequently used than other drugs in clinical peripheral blood stem cell transplantation(PBSCT).Many experiments confirm that rhG-CSF can reduce some cells adhesion molecules'expressions like CD49d,CD49e,CD49b,CD62L,CD44,CD58 and so on. But now there is no report about the effect of APS on the expression of adhesion molecules.Adhesion molecules conclude integrin family, selectin family, immunoglobulin gene super family and so on. The interaction between VLA-4 integrin expressed on HSC and its ligands,such as vascular cell adhesion molecuLe-1 (VCAM-1) on endothelial cell surface and fibronectin in matrix,plays a dominant role in how stem cells adhere to the BM microenvironment, and in how their lodging results in the transmission of proliferation and differentiation signals.CD44,which is highly expressed on both HSC and stromal cells,is described as a homing-associated adhesion molecule to mediate HSC homing on to BM via adhesion to the matrix ligands including hyaluronate,fibronectin and collagen.Therefore,we chose CD49d (a chain of VLA-4) and CD44 to represent the adhesion molecule in this study and to test which is more important in HSC mobilization.Sca-1+ cells are more primitive and have a high incidence and longer proliferation life span when cultured with stem cell factor(SCF) and stromal cells.We used Sca-1 antigen to represent murine HSC,and likewise used CD34 for human HSC, studying on mobilization of APS on hematopoietic stem progenitor cells and the expression of adhesion molecules on some hematopoietic cells. The objective of this research is to find a new and effective agent in hematopoietic stem cell mobilization and to provid theoretical and experimental evidence for clinical application and development of Angelica.In this research experimental animal model is BALB/c mice. Study on the effect of APS on the number of bone marrow and peripheral blood Sca-1+ cell, adhesion molecules expression and adhesion rate in murine hematopoietic cells. It will provide experimental evidence for exploiting and utilizing Angelica that APS is further researched in promoting mobilization of HSPC.Objective: To explore the effect of Angelica polysaccharides (APS) on the number of bone marrow and peripheral blood Sca-1+ cell,the expression of CD49d (a chain of VLA-4)and CD44 in murine hematopoietic cells and adhesive rate of murine bone marrow mononuclear cell to BM matrix(fibronectin ,FN).Methods: Observe the positive rate of Sca-1,the effect of APS on the expressions of CD49d and CD44 of murine hematopoietic cells by flow cytometry and the binding capacity of murine bone marrow and peripheral blood mononuclear cell to FN in vitro and in vivo by MTT assay .Results:1) In APS group(4mg/kg):the number of peripheral blood WBC and Sca-1 + cells were markedly more than that of NS group(P<0.01),and bone marrow MNC and Sca-1 + cells was significantly fewer than that of NS group (P <0.01);2) In APS group (4mg/kg): the expression of CD49d on hematopoietic cells significantly declined (P<0.05); the percent of CD44'expression on bone marrow MNC also decreased (P <0.05), but we did not observe any change of the mean fluorescence intensity at the same time, or that of CD44'expression on bone marrow Sca-1+ cells and peripheral blood WBC and Sca-1 + cells.3) After APS injected, the adhesive rate of APS group(4mg/kg) was markedly lower than that of NS group (P<0.01).4) With 100,200,300and 400μg/mL of APS, the adhesive rate was inferior than control group(P<0.05).Between certain concentration of (50～200μg/mL), the adhesive rate of bone marrow MNC to FN decreased, with the increase of cell concentration (P<0.05); Between certain concentration of (50～300μg/mL),the adhesive rate of peripheral blood MNC to FN decreased, with the increase of cell concentration (P<0.05);Conclusion: APS may increase the numbers of peripheral blood Sca-1+cells. Meanwhile, some hematopoietic cells adhesion molecules'expressions and the adhesive ability of murine mononuclear cells to FN declined, resulting in mobilizing hematopoietic stem and progenitor cells (HSPC) from the bone marrow into the peripheral blood.The results indicate that APS may be a new and effective agent in hematopoietic stem cell mobilization.