中文摘要：

目的建立一种温度敏感型干细胞株，为脑外伤患者接受亚低温治疗期间实施干细胞原位移植打下基础。方法用含温度敏感性猿猴病毒40大T抗原（tsSV40IX）的表达质粒转染人源性脐带间充质干细胞（UCMSCs），PCR检测外源基因的整合，绘制细胞生长曲线，检测其致瘤潜能；脑组织行增殖细胞核抗原（PCNA）免疫组化及原位细胞凋亡检测，实验动物予以神经功能缺陷评分。结果基因片段被成功整合，该细胞株在33℃时增殖旺盛，可耐受极低的营养条件，并可在软琼脂中形成小的细胞克隆；37℃时停止生长，低营养耐受力下降，无细胞克隆形成；亚低温治疗期间脑组织高表达PCNA，凋亡少见。结论温度敏感型干细胞株的建立使脑外伤患者在接受亚低温治疗期间实施干细胞原位移植提供了条件。

英文摘要：

Objective To establish a temperature -sensitive stem cell line for appropriating cells transplantation in injured brain area during patients accepting hypothermia treatment. Method After transfecting plasmid containing temperature - sensitive simian virus 40 large T - antigen （ tsSV40LT ） into umbilical cord mesenehymal stem cells （UCMSCs）, PCR was used to detect gene integration. Then cell growth curves were drawn in 33℃ and 37℃ respectively. Serum - dependent experimental and soft agar colony assay were used to examine the tumorigenesis of the stein cells. After TBI models in thymic mice were established, the stem cells were transplated into injured area. Proliferating cell nuclear antigen expression and in situ apoptosis were detected by immunofluorescence. Results The tsSV4OLT gene was integrated into UCMSCs successfully. When cultured at 33℃ incubator, the new cell line displayed high proliferation activity, strong tolerance to low nutrient conditions, and strong cell clone ability. But when cultured at 37℃ incubator, the cell line showed a converse profile. In vivo, the results showed that the brain tissue during hypothemlia treatment more highly expressed PCNA, and existed lower cell apoptosis, than normothermia group. Conclusions The stem cell line modified by tsSV4OLT is highly temperature -sensitive, and its proliferation activity can be regulated effectively, and that supports the clinical application of stem cells transplantation into injured brain area during hypothermia treatment.