寒冷刺激诱导大鼠棕色脂肪组织中的心脏干细胞增多

Cold Temperature Stimulating Cardiac Stem Cell Amplification in Rats'Brown Adipose Tissue

目的:检测寒冷刺激下大鼠肩胛部棕色脂肪组织中的心脏干细胞。方法:将大鼠随机分为2组,每组6只。实验组在寒冷环境下(4℃)饲养,对照组在常温条件(24℃)饲养。4周后分离肩胛部棕色脂肪比较两组脂肪组织活性。运用联合酶消化法提取并体外培养棕色脂肪来源细胞,使用流式方法检测相应细胞表面标记物的表达情况,体外培养4周后运用免疫荧光等技术检测心肌特异性抗原的表达,并比较不同细胞接种密度下自发心肌分化的效果。结果:饲养4周后,实验组较对照组大鼠肩胛部棕色脂肪中解偶联蛋白-1(UCP-1)表达增加,棕色脂肪来源细胞的CD133,CD29和CD29/CD133表达增加,差异均有统计学意义(P<0.01)。体外培养4周,细胞表达心肌特异性标志物。在不同的细胞接种密度下,实验组提取自发分化心肌细胞的效率最高可达(27.3±2.8)%,逆转录多聚酶链反应(RT-PCR)进一步证实心肌细胞相关基因表达阳性。相比之下,对照组提取的棕色脂肪来源细胞自发分化心肌样细胞的效率均较正常心肌组织微弱。结论:寒冷刺激下棕色脂肪中存在更多的心脏干细胞,提示温度对心脏干细胞体内定位或增殖具有一定作用。

Objective ：To investigate the cardiac stem cell amplification in brown adipose tissue （BAT） in rats with cold temperature stimulation. Methuds：The experimental rats were divided into two groups according to breeding temperature as 4℃ group and 24℃ group,n = 6 in each group. After 4 weeks breeding,rats＇ interscapular BAT was isolated and BAT specific protein UCP-I expression was examined. BAT-derived cells were obtained and the related cell phenotypic character was tested by flow cytometry. With 4 weeks in vitro culture, cardiomyocytes specific antigen was detected, and the efficiency of cell differentiation was compared at different inoculation density. Results：After 4 weeks breeding,in 4℃ group,the expression of UCP-1 protein and the expression of BAT-derived cell phenotypes CD133,CD29 and CD29/CD133 were significantly increased than those in 24℃ group,P〈0. 01. After 4 weeks in vitro cuhure,in 4℃ group, the cell differentiation efficiency reached （27.3±2.8 ）% at certain inoculation density which was higher than that in 24℃ group. A positive cardiac-specific gene expression was confirmed by RT-PCR. Conclusion：More cardiac stem cells exist in cold temperature stimulated BAT, which suggesting that the temperature may affect homing and differentiating of cardiac stem cell at certain point.