硒对心脏移植大鼠外周血单个核细胞免疫分子、基因表达的影响

Effect of Selenium on Expression of Immune Molecules and Multiple Gene in Peripheral Blood Mononuclear Cells from Allogeneic Heart Transplantation Rats

目的探讨微量元素硒对大鼠异体异位心脏移植后免疫排斥反应过程中免疫分子和基因表达的影响。方法大鼠分为对照及药物干预组。干预组分别于心脏移植术前后每天灌胃给予硒（40μg·kg^-1）及环孢素A（15mg·kg^-1），对照组给予同等体积生理盐水。3组分别在移植术前及术后1，3，7，10和12d取外周血，分离单个核细胞（PBMC）。荧光单克隆抗体（mAb）标记，流式细胞仪检测MHC-Ⅱ，CD4，CD8，R2-R和ICAM-Ⅰ免疫分子表达水平。荧光基因差异显示分析法检测多基因表达水平。国际器官移植排斥反应病理诊断标准对移植心肌组织进行病理分级。结果①对照组移植心脏存活率于术后3d时下降，7—12媳剧下降；硒组移植心脏存活率术后7d时下降，10—12d存活率为43％；环孢素A组术后3d移植心脏存活率下降50％，12d时为30％。②对照组及环孢素A组术后24h移植心肌组织分别有12．5％和33．3％发生Ⅱ级以上病理损伤，硒组术后7d出现Ⅱ级以上病理损伤。③与对照组比较，心脏移植术前后，硒对PBMC表面免疫分子MHGⅡ，CD8，IL-2R及ICAM-Ⅰ的表达均有抑制作用（P〈0．05或P〈0．01），环孢素A对ID2R有较强的抑制作用。④硒及环孢素A对心脏移植术后2，3-bisphosohoglycerate的mRNA表达均有抑制作用。与对照组比较，硒对gig18的mRNA为负调表达，环孢素A为正调表达。结论微量元素硒可能通过调节2，3-bisphosphoglycerate和gig18等细胞代谢和凋亡相关基因的转录，抑制PBMC表面免疫分子MHC-Ⅱ，CD8，IL-2R和ICAM-Ⅰ的表达，从而对心肌细胞起到保护作用，提高大鼠移植心脏存活率。

OBJECTIVE To investigate the effect of selenuim（Se） on the expression of immune molecules and multiple gene in peripheral blood mononuelear cells from the allogeneic heart transplantation rats. METHODS Rats were divided into control group, Se and CsA experimental group and orally treated with water, Se （40μg·kg^-1 ） and CsA （ 15 mg·kg^-1） respectively. Mononuclear cells from peripheral blood were collected at 1, 3, 7, 10 and 12 d pest-transplantation. Mono-clone antibodies were used to label surface molecules of the cells. The expression of MHC- Ⅱ, CD4, CD8 IL-2R and ICAM- Ⅰ was separately evaluated by flow-cytometer. The expression of multiple gene was evaluated by DD-PCR. Myocardial pathological changes were classified in according to the international standard. RESULTS ①In control group, the surrival rate of graft heart was reduced at 3^th day after transplantation and rapid reduced at 7 - 12 d. In Se grorp, the surrival rate of graft heart was reduced at 7th day and there was 43% surrival rate of graft heart at 10- 12 d.In CsA group,the surrival rate of graft heart was reduced by 50% at the 3th day after transplantation. There was 30% survival rate of graft heart at post-transplantation 12 d. ②The pathological damages of graft heart characterized with Ⅱ phase were 12.5% and 33.3% in control group and CsA group respectively after 24 h post-transplantation. In Se group, Ⅱ phase pathological alteration oceured after 7 day post-transplantation.③Compared with control group, the immune molecules of MHC- ③, CD8, IL-2R and ICAM- Ⅰ were significantly down-regulated in Se group（ P 〈 0.05 or P 〈 0.01）. Immune molecule IL- 2R was significantly down-regulated in CsA group. ④Compared with control group, Se and CsA inhibited the expression of 2,3-bisphosphoglyeerate. In Se group, the expression of gig18 was significantly down-regulated but up-regulated in CsA group. CONCLUSION Se increases the starival rate of graft heart and protects the graft heart by up and down-regulating genes transfer of 2,3-bisphosphoglyeerate and gig18 which relevant to cell metabolism and apoptosis and by inhibiting the expression of MHC- Ⅱ, CD8, IL-2R and ICAM-Ⅰ .