Stable CpG hypomethylation of adipogenic promoters in freshly isolated, cultured, and differentiated mesenchymal stem cells from adipose tissue
Stable CpG hypomethylation of adipogenic promoters in freshly isolated, cultured, and differentiated mesenchymal stem cells from adipose tissue
复制标题
DOI：
10.1091/mbc.e06-04-0322
复制
发表时间：
2006-08-01
影响因子：
3.3
通讯作者：
Collas, Philippe
中科院分区：
文献类型：
--
作者：
Noer, Agate;Sorensen, Anita L.;Collas, Philippe
来自脂肪组织的间充质干细胞可以分化成中胚层谱系。然而，脂肪干细胞 (ASC) 克隆之间的分化潜力存在差异，因此提出了表观遗传差异导致这种差异的假设。我们在这里报告了对新鲜分离的人 ASC 和培养的脂肪形成（瘦素 [LEP]、过氧化物酶体增殖物激活受体 γ 2 [PPARG2]、脂肪酸结合蛋白 4 [FABP4] 和脂蛋白脂肪酶 [LPL]）启动子和非脂肪形成（肌细胞生成素 [MYOG]、CD31 和 GAPDH）基因座的 CpG 甲基化的重亚硫酸盐测序分析。 ASC，与基因表达和分化潜力有关。未培养的 ASC 显示低甲基化的脂肪形成启动子，与甲基化的生肌和内皮基因座相反。脂肪形成启动子表现出马赛克 CpG 甲基化，其基础是细胞之间的异质甲基化以及供体之间以及克隆细胞系之间和内部的给定 CpG 甲基化程度的变化。 DNA 甲基化既不反映转录状态，也不反映分化时基因表达的潜力。 ASC 培养保留脂肪形成启动子的低甲基化；然而，检测到克隆间和克隆内嵌合甲基化。成脂分化还维持 LEP、PPARG2、FABP4 的整体 CpG 低甲基化。和 LPL，尽管特定 CpG 去甲基化和转录诱导。此外，与脂肪生成无关的原代分化细胞中脂肪生成基因座的甲基化增强证明了这些基因座的低甲基化状态的 ASC 特异性。因此，脂肪形成启动子的嵌合低甲基化可能构成ASC的分子特征，而DNA甲基化似乎并不是这些细胞分化潜力的决定因素。
Mesenchymal stem cells from adipose tissue can differentiate into mesodermal lineages. Differentiation potential, however, varies between clones of adipose stem cells (ASCs), raising the hypothesis that epigenetic differences account for this variability. We report here a bisulfite sequencing analysis of CpG methylation of adipogenic (leptin [LEP], peroxisome proliferator-activated receptor gamma 2 [PPARG2], fatty acid-binding protein 4 [FABP4], and lipoprotein lipase [LPL]) promoters and of nonadipogenic (myogenin [MYOG], CD31, and GAPDH) loci in freshly isolated human ASCs and in cultured ASCs, in relation to gene expression and differentiation potential. Uncultured ASCs display hypomethylated adipogenic promoters, in contrast to myogenic and endothelial loci, which are methylated. Adipogenic promoters exhibit mosaic CpG methylation, on the basis of heterogeneous methylation between cells and of variation in the extent of methylation of a given CpG between donors, and both between and within clonal cell lines. DNA methylation reflects neither transcriptional status nor potential for gene expression upon differentiation. ASC culture preserves hypomethylation of adipogenic promoters; however, between- and within-clone mosaic methylation is detected. Adipogenic differentiation also maintains the overall CpG hypomethylation of LEP, PPARG2, FABP4. and LPL despite demethylation of specific CpGs and transcriptional induction. Furthermore, enhanced methylation at adipogenic loci in primary differentiated cells unrelated to adipogenesis argues for ASC specificity of the hypomethylated state of these loci. Therefore, mosaic hypomethylation of adipogenic promoters may constitute a molecular signature of ASCs, and DNA methylation does not seem to be a determinant of differentiation potential of these cells.