三氧化二砷对MRL／lpr自发性狼疮小鼠抗双链DNA抗体和DNA甲基转移酶及CD11a表达的影响

Effects of arsenic trioxide on anti-dsDNA antibody and the expression of DNA methyltransferase 1 and CD11a genes in lupus MRL/Ipr mice

目的探讨三氧化二砷（ATO）对MRL／lpr自发性狼疮小鼠抗双链DNA（dsDNA）抗体及DNA甲基转移酶1（DNMT1）和黏附分子淋巴细胞功能相关抗原-1（LFA-1）的亚基CD11a表达的影响及其可能作用机制。方法将MRL／lpr狼疮鼠随机分为ATO治疗组、019％氯化钠注射液（Ns）对照组和环磷酰胺组。另设正常C57／BL小鼠，随机分为ATO治疗组和NS对照组。以上每组各10只，隔日腹腔注射，给药2个月后处死，SYSMEXKX21血常规测定仪测定血常规，酶联免疫吸附试验（ELISA）法测各组小鼠血清抗dsDNA抗体水平；反转录．聚合酶链反应（RT-PCR）检测2组小鼠外周血单个核细胞的DNMT1及CD11a转录水平的表达情况。采用方差分析和配对t检验进行统计学处理。结果①MRL／lpr小鼠ATO治疗组血清抗dsDNA抗体水平（0．89±0．07）和CD11a（0．43±0．25）均低于Ns对照组（1．77±0．28，P〈0．01和0．99±0.31，P〈O．05），DNMTl（0．32±0．30）高于NS对照组（0．16±0．26，P〈0．05）；②MRL／lpr小鼠ATO治疗组及环磷酰胺治疗组小鼠的血清抗dsDNA抗体水平（分别为0．90±0．07和0．66±0．22）较Ns组（1．77±0．28）下降，且ATO治疗组小鼠的血清抗dsDNA抗体水平高于环磷酰胺治疗组（P〈0．05）；ATO组DNMTl（0．32±0．30）高于环磷酰胺治疗组（0．16±0．18，P〈0．05），CD11a（0．43±0．25）低于环磷酰胺治疗组（0．86±0．31，P〈0．05）；③在C57／BL小鼠中，ATO治疗组和NS对照组之间以上指标差异均无统计学意义。结论ATO能减少狼疮小鼠体内自身抗体产生，逆转其低甲基化状态；但是对正常小鼠的抗体水平和其甲基化状态并无明显影响。

Objective To investigate the effect of arsenic trioxide （ATO） on anti-dsDNA antibody and the expression of DNA methyhransferase 1-mRNA and CDlla-mRNA in lupus MRL/lpr mice. Methods MRL/lpr mice were divided into three groups： the ATO group, the sodium chloride （NS） group, and the cyclophosphamide （CTX） group. The control group consisted of 20 syngeneic normal C57/BL mice, which were subdivided into the ATO group and the NS group. After two-month treatment, all mice were sacrificed. Blood routine test was conducted by SYSMEX KX21. The anti-dsDNA antibody in the serum were detected by ELISA. The expression of DNMT1 and CDlla was determined by RT-PCR. ANOVA and paired t test were used for statistical analysis. Results （1） The serum level of anti-dsDNA antibody （0.89±0.07） and the gray scale value of CDlla-mRNA （0.43±0.25） in the ATO group were much lower than those in the NS group of MRL/lpr mice （1.77±0.28, P〈0.01; 0.99±0.31, P〈0.05）, while the gray scale value of DNMTI-mRNA （0.32±0.30） was significantly higher than that in the NS group （0.16±0.26, P〈0.05）. （2） The serum levels of anti-dsDNA antibody was low in both the ATO group and the CTX group （0.90±0.07, 0.66±0.22）, and it washigher in the ATO group than that in the CTX group （P〈0.05）. The gray scale value of DNMT1 mRNA in the ATO group （0.32±0.30） was higher than that in the CTX group （0.16±0,18, P〈0.05） in MRL/lpr mice, and the gray scale value of CDlla mRNA in the ATO group （0.43-±0.25） was lower than that in the CTX group （0.86±0.31, P〈0.05） in MRL/Ipr mice. （3） There was no difference in above param,ters between the ATO group and NS group in C57/BL mice （P〉0.05）. Conclusion Arsenic trioxide cab reduce the serum level of auto-antibody and reverse low methylation. But it has no effect on normal mice.