目的:观察不同剂量1,25-二羟基维生素D3(1,25-(OH)2D3)短期应用对大鼠受致死剂量脂多糖(LPS)攻击后的保护作用,并探讨此保护作用是否与1,25-(OH)2D3对CD4+CD25+Treg细胞的调节作用有关.方法:将大鼠分成3个剂量组,每组20只.分别给予1,25-(OH)2D3 0.125μg/只、0.25μg/只、1μg/只灌胃,3次/周,共2周.另设对照组给予赋形剂.给药后第15天腹腔注射致死剂量 LPS(10mg/kg),每组10只用于观察96 h内的死亡率;其余10只大鼠注射LPS6h后抽取外周血并留取脾脏标本.流式细胞仪检测大鼠外周血及脾脏CD4+CD25+Treg细胞数量,实时定量PCR检测脾脏Foxp3m R NA水平,ELISA检测外周血IL-10和TGF-β水平.结果:用1,25-(OH)2D3预处理的各组大鼠死亡率均显著低于对照组,用药各组外周血及脾脏CD4+CD25+Treg细胞数量、脾脏Foxp3mRNA表达水平、外周血IL-10及TGF-β水平也显著高于对照组.结论:1,25-(OH)2D3能够有效保护大鼠抵抗致死剂量LPS的攻击,这种保护作用可能与1,25-(OH)2D3上调CD4+CD25+Treg细胞的数量和功能有关.%Objective: We evaluated the protective effects of 1,25- (OH)2D3 in rats given lethal closes of lipopolysaccharide and investigated whether such protection was related to CD4+CD25+Treg cells. Methods:80 Inbred male Lewis rats were divided into 4 groups and treated with either 0.125 ug, 0.25 ug, 1 ug of 1,25-(OH)2D3 or vehicle by gavage 3 times a week for 2 weeks. On day15, all rats were given lethal doses of lipopolysaccharide (LPS,10mg/kg,I.p.) and the mortality of 10 rates of each group in were recorded within a 96 hour period. Six hours after LPS injection,peripheral blood and spleen tissue of the remaning rats were taken to count CD/CD25+ Treg cells by flow cytometry. Expression of Foxp3mRNA in spleen was measured by real-time PCR method. Results: The mortality rates of rats pre-treated with 1,25- (OH)2D3 were significantly lower than the control group.The number of CD/CD25+ Treg cells, the expression of Foxp3mRNA in spleen, and IL-10 and TGF- β levels in the peripheral blood in these groups were Significantly higher than the control group. Conclusion; 1,25-(OH)2D3 can effectively protect rats from a lethal dose of LPS. This protection may be related to the up-regulation of the number and function of CD/CD25+ Treg cells by 1,25-(OH)2D3.
展开▼
