Zhao Ming-liang, Chen Yi-sheng, Li Xiao-hong, Wang Jing-jing, Tu Yue, Sun Hong-tao, Zhang Sai, Chen Chonga
Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2015 May;31(3):207-10, 215.
To simulate the chemical microenvironment of injured brain tissue, and to explore the effect of this chemical microenvironment on temperature sensitive umbilical cord mesenchymal stem cells (tsUC).
Rat models of traumatic brain injury (TBI) were made by fluid percussion injury, and then the brain tissue extracts of the injured regions were acquired. Human umbilical cord mesenchymal stem cells (UC) were isolated and cultured, and the tsUC were obtained through the infection of temperature-sensitive Simian 40 Large T- antigen (ts-SV40LT) retrovirus. After that, both the two kinds of cells were cultured on the polyacrylamide gels which mimicking the elastic modulus of brain. Four groups were included: UC cultured under normal temperature (UC group), UC cultured added brain tissue extract under normal temperature (UC plus extract group), tsUC cultured under mild hypothermia (tsUC group), and tsUC added brain tissue extract under mild hypothermia for 3 days, then normal temperature for 4 days (tsUC plus extract group). After 24 hours, the apoptosis level was checked. Cell growth and morphological changes in each group were given dynamic observation. Seven days later, cell immunofluorescences were implemented for examining neural differentiation level.
Compared with UC plus extract group, the apoptosis and proliferation in UC plus extract group were significantly reduced (P < 0.01) and increased (P < 0.01) respectively. Cell immunofluorescence showed that the both GFAP and Neuron positive cells were significantly enhanced in UC plus extract group than those in tsUC plus extract group.
tsUC combining with mild hypothermia could significantly reverse injury induced cell apoptosis, improve cell proliferation and neural differentiation under chemical microenvironment after brain injury, which confirmed the adaptation and resistance of tsUC under mild hypothermia after TBI.
模拟损伤脑组织的化学微环境，探讨该化学微环境对温度敏感型脐带间充质干细胞（tsUC）的影响。
采用液压冲击伤制作大鼠创伤性脑损伤（TBI）模型，然后获取损伤区域的脑组织提取物。分离培养人脐带间充质干细胞（UC），通过感染温度敏感型猿猴病毒40大T抗原（ts-SV40LT）逆转录病毒获得tsUC。之后，将两种细胞接种于模拟脑弹性模量的聚丙烯酰胺凝胶上培养。分为四组：常温培养的UC组、常温下添加脑组织提取物培养的UC组（UC加提取物组）、亚低温培养的tsUC组、亚低温下添加脑组织提取物培养3天，然后常温培养4天的tsUC组（tsUC加提取物组）。24小时后，检测细胞凋亡水平。动态观察各组细胞生长及形态变化。7天后，进行细胞免疫荧光检测以观察神经分化水平。
与UC加提取物组相比，UC组凋亡明显减少（P<0.01），增殖明显增加（P<0.01）。细胞免疫荧光显示，UC加提取物组中GFAP和神经元阳性细胞均明显高于tsUC加提取物组。
tsUC联合亚低温可显著逆转脑损伤化学微环境下损伤诱导的细胞凋亡，改善细胞增殖及神经分化，证实了TBI后tsUC在亚低温下的适应性和耐受性。
