中文摘要：

目的 利用9.4 T高分辨率MRS离体检测间充质干细胞（MSCs）死亡的代谢特征.方法 培养获取MSCs,在模拟缺血、缺氧及内环境变化等因素的缺氧缓冲液中分别对MSCs诱导处理6、12及24 h.利用光学显微镜、Hoechst染色及流式细胞仪检测细胞死亡形式及死亡个数,对各时间点细胞死亡个数的组间比较采用单因素方差分析.利用甲醇/氯仿提取MSCs代谢物,经后处理后利用9.4 T MRS离体检测提取物的氢质子波谱,定量计算各时间点主要代谢物浓度,各时间点细胞代谢物浓度的组间比较采用单因素方差分析,两两比较采用SNK法.结果 MSCs在缺氧缓冲液中死亡的形式主要为坏死.所观察的各时间点细胞的死亡数分别为0 h（16±4）、6 h（658±61）、12 h（1 571±154）和24 h（2 816±178）个/万,各时间点间比较差异有统计学意义（F=298.96,P＜0.01）.诱导干细胞死亡后6、12和24 h后,位于0.89 ppm的脂质峰代谢物浓度分别为（1.48±0.69）、（2.32±0.63）和（2.15±0.45） nmol/mg,较对照组浓度[（1.41±0.25） nmol/mg]增高,且差异有统计学意义（F=329.57,P＜0.01）.位于1.28 ppm的脂质峰代谢物浓度分别为（6.42±0.31）、（7.26±0.32）和（7.01±0.61） nmol/mg,较对照组浓度[（5.76±0.74） nmol/mg]增高,且差异有统计学意义（F=19.56,P＜0.01）.位于1.60 ppm的脂质峰代谢物浓度分别为（2.36±0.31）、（2.29±0.16）和（2.31±0.24） nmol/mg,较对照组浓度[（1.96±0.27）nmol/mg]增高,且差异有统计学意义（F=4.35,P＜0.05）.两两比较：诱导干细胞死亡12h时,位于0.89和1.28 ppm的脂质峰浓度较6h增高,且差异有统计学意义（P值均＜0.05）;诱导干细胞死亡24 h时,位于0.89 ppm的脂质峰代谢物浓度较12h下降,且差异有统计学意义（P＜0.05）.结论 MSCs死亡的波谱变化具有一定特征,脂质峰的改变可作为判断细胞死亡的代谢标识.

英文摘要：

Objective To explore the metabolite profiles of mesenchymal stem cells（MSCs）underwent death using 9.4 T high resolution MR spectroscopy.Methods MSCs were cultured and treated for 6,12 and 24 hours in a stimulated condition which included hypoxia,serum deprivation and changes of microenvironment.Cell death and the mortality was detected by light microscopy,Hocchst staining and flow cytometry analyses.The morality of stem cells was analyzed using one-way analysis of variance （ANOVA）.Cell metabolite extraction was prepared by methanol-chloroform（M/C） method and analyzed on a 9.4 T MR device.1H-MR spectroscopy was obtained and the metabolite concentration of each time point was calculated and compared using one way ANOVA,the difference between two groups was analyzed by SNK test.Results Necrosis was the major form of cell death in the built model.The morality of every time sets was 16±4（0 h）,658±61 （6 h）,1 571 ± 154（12 h） and 2 816± 178（24 h） respectively,and the difference between each groups were statistically significant （F=298.96,P＜0.01）.After induced stem cells death for 6,12 and 24 h,the metabolite concentrations at 0.89 ppm was （1.48±0.69）,（2.32±0.63）and （2.15±0.45）nmol/mg respectively,and increased compared to thc control[（1.41 ±0.25）nmol/mg]with statistical significance （F=329.57,P＜0.01）.The metabolite concentrations at 1.28 ppm was （6.42±0.31）,（7.26±0.32）and （7.01 ±0.61）nmol/mg,respectively,and increased compared to the control[（5.76 ±0.74）nmol/mg]with statistical significance （F=19.56,P＜0.01）.The metabolite concentrations at 1.60 ppm was （2.36±0.31）,（2.29±0.16）and （2.31 ± 0.24） nmol/mg respectively,and increased compared to the control[（1.96 ± 0.27）nmol/mg]with statistical significance （F=4.35,P＜0.05）.After induced stem cells death for 12 hours,the metabolite concentrations at 0.89 ppm was increased compared to 6 hours with statistical significance （P＜0.05）.The metabolite concentrations