目的 研究黄芪多糖（APS）对甲醛染毒人骨髓间充质干细胞（BM-MSCs）DNA损伤的保护作用及潜在机制。方法 体外培养人BM-MSCs，随机分为对照组、模型组（甲醛）和APS 40、100、400 μg/mL组。利用MTT法检测细胞增殖活性，彗星实验检测DNA断裂，KCl-SDS沉淀实验检测DNA-蛋白交联（DPCs），qRT-PCR和Western blotting检测着色性干皮病基因A（XPA）、着色性干皮病基因C（XPC）、DNA修复切除修复交叉互补基因1（ERCC1）、复制蛋白A1（RPA1）、复制蛋白A2（RPA2）mRNA和蛋白表达水平。结果 与模型组比较，APS 40、100、400 μg/mL作用后，细胞增殖活性显著升高（P<0.01），DNA断裂和DPCs形成显著减少（P<0.01），XPA、XPC、ERCC1、RPA1、RPA2 mRNA和蛋白表达水平显著升高（P<0.05、0.01），其中APS 100 μg/mL组效果最明显。结论 APS可以保护甲醛诱导的人BM-MSCs DNA损伤，APS 100 μg/mL保护作用最为明显，其机制可能与上调XPA、XPC、ERCC1、RPA1和RPA2基因表达，促进DNA修复有关。

Objective To study the protective effect of Astragalus Polysaccharide (APS) on DNA damage in human BM-MSCs exposed to formaldehyde and to initially explore the potential mechanism. Methods BM-MSCs were cultured in vitro and divided into control group, formaldehyde group, and APS at 40, 100, and 400 μg/mL groups. Proliferation activity was measured by MTT assay, DNA strand breakage was detected by comet assay, DNA-protein crosslinks (DPCs) was detected by KCl-SDS precipitation assay, and the mRNA and protein expression of XPA, XPC, ERCC1, RPA1 and RPA2 were detected by qRT-PCR and Western blotting. Results Compared with model group, formaldehyde-contaminated BM-MSCs were treated with APS at 40, 100, and 400 μg/mL, the cell proliferation activity was increased significantly (P < 0.01), DNA strand breakage and DPCs level were decreased significantly (P < 0.01), and the mRNA and protein expression of XPA, XPC, ERCC1, RPA1, and RPA2 were up-regulated significantly (P < 0.05, 0.01). Among them, the effect of 100 μg/mL APS group was the most obvious. Conclusion APS can protect formaldehyde-induced BM-MSCs DNA damage, especially 100 μg/mL APS has the most obvious effect. The mechanism may be associated with the up-regulation of XPA, XPC, ERCC1, RPA1, and RPA2, which promoted the repair of DNA damage.

R285.5

国家自然科学基金资助项目（81560667）；甘肃省自然科学基金资助项目（1506RJZA045）