Effects Of Ginsenosides Rg1 On Prolifferation, Diffireation And Calcium-sensing Receptor Of Human Umbilical Cord Blood CD34~+ Hemopoietic Stem Cells

Objective:To observe the effect of ginsenosides Rg1 (Rg1) on the proliferation and differentiation of human umbilical cord blood hemopoietic stem cells (hUCB-HSCs) and investigate the underlying mechanism of action.Methods:Density gradient centrifugation and magnetic cell sorting assay were used simultaneously to separate and purify the hUCB-HSCs, The cell differentiation antigens were detected by flow cytometry. hUCB-HSCs were cultured and treated with different groups [Rgl 0.1μmol/L-3μmol/L, calcium sensing receptor (CaSR) blocking agent CdCl2 0.1μmol/L and CaSR agonist GdCl2 0.3μmol/L]. The cell morphology were observed under inverted phase contrast microscope. Expression of CaSR mRNA was detected by RT- real time PCR. The CaSR protein expression were observed by immunofluorescence staining.Results:Outcomes of flow cytometry revealed the purity of hUCB CD34+ HSCs reach to (81.57±12.95)%. After cultured hUCB CD34+ HSCs 14days, compared with control group, the number of colony forming of burst-forming unit erythroid (BFU-E), colony forming unit-granulocyte macrophage (CFU-GM) and colony forming unit-mixture(CFU-GEMM) were markedly increased in Gdcl3 and all Rg1 group, but decreasd in CdCl2(P<0.05). The number of hUCB-HSCs increased slowly from 1st to 6th, then increased fast and reached maximum colony at 14th day. Compared with Rgl group, the cells number of hUCB- HSCs were decreased remarkably in CdCl2 +Rg1 group, but were more than CdCl2 group. When hUCB CD34+ HSCs were cultured 14days, the percentages of expressed CD11b+,CD15+, Cd71+, GA+and CD61+cells were no obviously significant difference in GdCl3 and all Rgl dose groups (P>0.05), compared with control group and each other groups. At cultured hUCB-HSC 10days, the expression of CaSR mRNA and protein were no significant difference in Rgl and CdCl2, GdCl3 group compared with control group and each other. Immunofluorescence staining showed CaSR highly expressed on hUCB CD34+ HSC at from Od to 10 days.Conclusion:Ginsenosides Rgl and CaSR agonist GdCl2 can markedly promote the proliferation of hUCB CD34 positive HSCs, but has no influence on differentiation. The effect of Rgl on proliferation of HSCs were notablely inhibted by CdCl2. Expression of CaSR mRNA and protein were no changed by Rgl, GdCl2 and CdCl2. maight upregulate CaSR activity, then promot proliferation of hUCB CD34+ HSCs. Rgl may be a CaSR agonist.