AIM:To explore the protective effects of salidroside on endothelial progenitor cells (EPCs) dam-aged by radiation and its mechanisms.METHODS:EPCs from normal peripheral blood were cultured in fibronectin-coated flasks with endothelial progenitor medium.The effects of salidroside on the viability, migration, adhesion and apoptosis of radiation-damaged EPCs were detected.The viability, apoptosis and migration of the cells were assayed by CCK-8 assay, flow cytometry and Transwell chamber experiment, respectively.The cell adhesion assay was performed by re-plating the cells on fibronectin-coated dishes, and then the adherent cells were counted.The expression of Akt protein in the cells was assessed by Western blotting.RESULTS:Salidroside improved the viability, and migratory and adhesive capacities of the EPCs, and decreased the apoptosis after radiation.Salidroside also increased the protein level of phosphorylated Akt.How-ever, the effects of salidroside on radiation-damaged EPCs were inhibited by phosphatidylinositol 3-kinase inhibitor LY294002.CONCLUSION: Salidroside protects EPCs from radiation damages and its mechanism is associated with en-hancing phosphatidylinositol 3-kinase/Akt signaling pathway.

Objective To investigate the potential and underlying molecular mechanism of salidroside in ameliorating radiation-induced bone marrow adipogenesis and stimulating hematopoiesis.Methods The female BALB/c mice aged 6-7 weeks were randomly divided into normal control group,radiation group and salidroside group.The radiation group and salidroside group were irradiated with 6.0 Gy of 60Co γ-rays.The salidroside group was intraperitoneally injected with 30 mg· kg-1 · d-1 salidroside at 12 h and then every day until 8th d after radiation.The normal control group and radiation group were treated with equal volume of saline as control of salidroside.At 14 d after radiation,the mice weight,peripheral blood count,femur bone marrow histology,and the proportion of adipocyte area were measured,and the expressions of PPAR-γ and FABP4 were detected by q-PCR.Results After irradiation,the numbers of white blood cells,hemoglobin and platelet in peripheral blood were reduced obviously,and the percentage of adipocyte area was increased significantly.Compared with mice in the radiation group,salidroside inhibited adipogenesis and reduced the proportion of adipocyte area (t =13.31,P ＜ 0.05) by reducing the expressions of PPAR-γ and FABP4 (t =8.64,13.19,P ＜ 0.05).The number of white blood cells was partly recovered at 7 d after irradiation (t =5.80,P ＜ 0.05).Both white blood cells and hemoglobinin in peripheral blood of the salidroside group were higher than those in the radiation group at 14 d after irradiation.Conclusions Salidroside could inhibit radiation-induced bone marrow adipogenesis and regulate bone marrow microenvironment,thereby promotes hematopoietic recovery in mice after radiation injury.

[ABSTRACT]AIM:ToinvestigatetheeffectofmiR-155-specificsiRNAaloneorincombinationwithcytosinear-abinoside (Ara-C) on the growth and apoptosis of Burkitt lymphoma Raji cells .METHODS: miR-155-specific siRNA and/or Ara-C were used to treat the cells .Quantitative real-time polymerase chain reaction was used to detect the expres-sion of miR-155.The growth of the cells was analyzed by CKK-8 assay.The cell apoptosis was determined by flow cytome-try.RESULTS:The miR-155 expression level of the cells transfected with miR-155 siRNA was significantly lower than that in the 2 control groups .Ara-C or miR-155 siRNA alone inhibited the growth of Raji cells in a dose-depend manner . miR-155 siRNA combined with Ara-C produced more inhibition of cell proliferation (P<0.05).After treatment for 48 h, the apoptotic rate of Raji cells in miR-155 siRNA+Ara-C group [(38.4 ±1.4)%] was higher than that in Ara-C group [(16.5 ±0.3)%] and miR-155 siRNA group [(14.6 ±0.3)%], with statistically significant difference (P<0.05). The expression of caspase-3 in Ara-C+miR-155 siRNA group was increased significantly as compared with Ara-C group and miR-155 siRNA group.CONCLUSION:miR-155-specific siRNA enhances the chemosensitivity of Raji cells to Ara-C by inducing apoptosis through the caspase-3 pathway .

AIM: To investigate whether salidroside has influence on the activities of endothelial progenitor cells (EPCs) and its mechanism.METHODS:Mononuclear cells from normal human peripheral blood were cultured in fi-bronectin coated flasks in endothelial progenitor medium .After 7 d, EPCs were characterized as adherent cells with acLDL-DiI uptaking and lectin binding by direct fluorescent staining .The proliferation and migration of EPCs were analyzed by MTT assay and Transwell chamber assay , respectively.The EPCs adhesion assay was performed by re-plating the cells on fibronectin-coated dishes , and then adherent cells were counted .NO and Akt protein were also detected .RESULTS:Sali-droside promoted EPCs proliferative , migratory and adhesive capacities in a concentration dependent manner .Salidroside also increased NO secretion , and the level of phosphorylated Akt protein .However , the effects of salidroside on EPCs were inhibited by phosphoinositide 3-kinase inhibitor LY294002.CONCLUSION:Salidroside regulates the activity of EPCs by phosphoinositide 3-kinase/Akt signaling pathway .