中文摘要：

目的：探索DNA酶I处理后骨髓间充质干细胞降低急性肺栓塞的发生。方法：体外培养小鼠骨髓间充质干细胞。C57小鼠分PBS注射组、10U／mLDNaseI—PBS注射组、正常BMSCs注射组、DNaseI处理后BMSCs注射组。PBS注射组与正常BMSCs注射组尾静脉注射PBS或临界致死剂量的BMSCs，脏器组织学检测，PBS注射组对照，观察急性死亡率；比较正常BMSCs与DNaseI处理后BMSCs体外增殖、分化能力和悬液中细胞聚集状态；DNaseI处理后BMSCs注射组注射DNaseI处理后3×10^6个BMSCs5ml／kg观察急性死亡率。结果：PBS注射组相比正常BMSCs注射组急性死亡率为60oA、心肺异常、肺血管内异染物质，急性肺栓塞；DNaseI预处理不影响BMSCs体外增殖分化能力；DNaseI处理BMSCs较正常BMSCs聚集成团细胞比例显著下降。DNaseI处理后BMsCs注射组的急性死亡率为23．3％，与正常BMSCs注射组比较差异显著。结论：DNaseI预处理不影响BM—SCs的生物学特性并能抑制单细胞聚集降低静脉注射BMSCs所导致的急性肺栓塞。

英文摘要：

Objective： To investigate a novel method to reduce the occurrence of pulmonary embolism after BMSCs injection by using DNase I pretreatment. Methods： Mouse BMSCs were isolated, cultured and purified to the 3rd generation in vitro. C57BL/6 mice were divided into 4 groups： PBS injection group, 10U/ml DNase I-PBS injec- tion group, BMSCs injection group and DNase I pretreated BMSCs injection group. Acute death rate were calculated and different organs of dead mice were examined by histological analysis. Proliferation and differentiation ability a- long with aggregation status in cell suspension of BMSCs before and after DNase I treatment were detected in vitro. Result： The acute death rate of BMSCs injection group was 40% lower than PBS injection group, and histological examination revealed cardiopneumatic abnormality. Some deeply stained masses were found in pulmonic vessel. DNase I pretreatment did not affect the proliferation and differentiation ability of BMMSCs in vitro, but the propor- tion of aggregated cells declined significantly. The acute death rate of DNase I pretreated BMSCs injection group was 23.3%, which was significantly lower than BMSCs injection group. Conclution： DNase I pretreatment would not af- fect the biological character of BMSCs but could inhibit single cell aggregation.