ABSTRACT
This study is to investigate the protective effects of the SB203580 against radiation induced mortality and intestinal injury of mice. A total of 67 male C57BL/6 mice (20.0-22.0 g) were matched according to body weight and randomly assigned to one of three groups: control, total body irradiation exposure (IR, 7.2 Gy) only, and IR (7.2 Gy) + SB203580 (15 mg x kg(-1)). 30 days survival rate was observed in the experiment. In intestinal injury experiment, the expression levels of caspase-3, Ki67, p53 and p-p38 were assayed in the mice intestine crypts. The results showed that the 30 days survival rate was 100% (control), 0 (IR) and 40% (IR+ SB203580), separately. Compared to the IR groups, the positive cells of caspase-3, p53 and p-p38 in crypt cells decreased 33.00%, 21.78% and 34.63%, respectively. The rate of positive cells of Ki67 increased 37.96%. Significant difference was found between all of them (P < 0.01). SB203580 potently protected against radiation-induced lethal and intestinal injury in mice, and it may be a potential radio protector.
ABSTRACT
BACKGROUND:Bone marrow mesenchymal stem cells have low immunogenicity and immunomodulatory effect,but there are seldom reports concerning the immunomodulatory effect of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord and its mechanims.OBJECTIVE:To investigate the immunomodulatory effects and mechanisms of Wharton's jelly-derived mesenchymal stem cells of human umbilical cord on varient peripheral blood T lymphocytes.METHODS:Mesenchymal stem cells were isolateded from Wharton's jelly of human umbilical cord by tissue culture.T lymphocytes from human peripheral blood were stimulated by phytohemagglutinin and co-cultured with umbilical cord Wharton's jelly-derived mesenchymal stem cells and umbilical cord Wharton's jelly-derived mesenchymal stem cells supernatant respectively to measure A value following 72 hours of coculture using multifunctional microplate reader.Expression of cytokines including transforming growth factor-beta 1(TGF-β1)and interferon-y(IFN-γ)was evaluated by enzyme-labeled immunosorbent assay.RESULTS AND CONCLUSION:Wharton's jelly-derived mesenchymal stem cells could inhibite the proliferation of T lymphocytes induced by phytohemagglutinin.The proliferation inhibition rate was 56%(P＜0.01).Wharton's jelly-derived mesenchymal stem cells supernatant also had inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin,in a dose-dependent fashion.The proliferation inhibition rates were 8.3% and 27% respectively in the 50% Wharton's jelly-derived mesenchymal stem cells supernatant and 100% Wharton's jelly-derived mesenchymal stem cells supematant groups(P＜0.05).Wharton's jelly-derived mesenchymal stem cells significantly decreased γ-interferon secrted from T-lymphocytes(P＜0.05).The secretion of TGF-β1 was lower in the coculture of Wharton's jelly-derived mesenchymal stem cells and T lymphocytes group than Wharton's jelly-derived mesenchymal stem cells alone group(P＜0.05).These indicated that Wharton's jelly-derived mesenchymal stem cells and Wharton's jelly-derived mesenchymal stem cells supernatant have inhibitory effects on proliferation of T lymphocytes induced by phytohemagglutinin.The mechanims may be associated with cell contant and inhibition of v-interferon secrted from T-lymphocytes.