大鼠棕色脂肪干细胞与白色脂肪干细胞成骨能力的比较

Osteogenic potential of different adipose derived stem cells in rats

目的比较大鼠棕色脂肪干细胞（brown adipose stem cell，BADSC）和白色脂肪干细胞（white adipose stem cell，WADSC）的体外成骨能力，为脂肪源性干细胞的进一步研究和临床应用提供依据。方法分离SD大鼠肩胛骨下棕色脂肪及腹股沟处白色脂肪组织，获得BADSC和WADSC。倒置相差显微镜观察细胞形态，细胞计数检测增殖能力。成骨诱导后进行碱性磷酸酶（alkaline phosphatase，ALP）染色及茜素红染色。实时荧光定量PCR（quantitative real-time PCR，qPCR）检测成骨标志基因[Runt相关转录因子2（Runt-related transcription factor-2，RUNX2）、骨钙蛋白]的表达情况。结果BADSC和WADSC均可成骨向分化。成骨诱导后各时间点BADSC的ALP活性均显著大于WADSC；成骨诱导5周后BADSC形成面积较大的钙结节（累积光密度为92 558±1 507），显著大于WADSC（累积光密度为52 319±1 786）（t=29.81，P〈0.05）。BADSC成骨标志基因（RUNX2和骨钙蛋白）的表达均显著大于相同时间点WADSC（P〈0.05）。结论BADSC和WADSC均具有成骨分化的潜能，但BADSC成骨分化能力强于WADSC。

Objective To compare the in vitro osteogenic ability of brown adipose stem cells （BADSC） and white adipose stem cells （WADSC）, and to provide evidence for further research and clinical application of adipose-derived stem cells.Methods The brown fat under the scapula of SD rats and the white adipose tissue in the groin were isolated and obtained BADSC and WADSC. The morphology of the cells was observed by an inverted phase contrast microscope, and the cell count was used to detect the proliferative ability. After osteogenic induction, alkaline phosphatase （ALP） staining and alizarin red staining were performed. The expression of the osteogenic marker gene [Runt-related transcription factor-2 （RUNX2）, osteocalcin] was detected by quantitative real-time PCR （qPCR）.Results Both BADSC and WADSC were osteogenic. The ALP activity of BADSC was significantly greater than that of WADSC at each time point after osteogenic induction. After 5 weeks of osteogenic induction, BADSC formed a larger area of calcium nodules （accumulated optical density was 92 558±1 507）, which was significantly greater than WADSC （accumulated optical density was 52 319±1 786） （t=29.81, P〈0.05）. The expression of BADSC osteogenic marker genes （RUNX2 and osteocalcin） was significantly higher than that of WADSC （P〈0.05）.Conclusions Both BADSC and WADSC have the potential for osteogenic differentiation, but BADSC has better osteogenic differentiation ability than WADSC.