Department of Fixed Prosthodontics, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
PLoS One. 2010 Sep 14;5(9):e12743. doi: 10.1371/journal.pone.0012743.
Induced pluripotent stem (iPS) cells efficiently generated from accessible tissues have the potential for clinical applications. Oral gingiva, which is often resected during general dental treatments and treated as biomedical waste, is an easily obtainable tissue, and cells can be isolated from patients with minimal discomfort.
METHODOLOGY/PRINCIPAL FINDINGS: We herein demonstrate iPS cell generation from adult wild-type mouse gingival fibroblasts (GFs) via introduction of four factors (Oct3/4, Sox2, Klf4 and c-Myc; GF-iPS-4F cells) or three factors (the same as GF-iPS-4F cells, but without the c-Myc oncogene; GF-iPS-3F cells) without drug selection. iPS cells were also generated from primary human gingival fibroblasts via four-factor transduction. These cells exhibited the morphology and growth properties of embryonic stem (ES) cells and expressed ES cell marker genes, with a decreased CpG methylation ratio in promoter regions of Nanog and Oct3/4. Additionally, teratoma formation assays showed ES cell-like derivation of cells and tissues representative of all three germ layers. In comparison to mouse GF-iPS-4F cells, GF-iPS-3F cells showed consistently more ES cell-like characteristics in terms of DNA methylation status and gene expression, although the reprogramming process was substantially delayed and the overall efficiency was also reduced. When transplanted into blastocysts, GF-iPS-3F cells gave rise to chimeras and contributed to the development of the germline. Notably, the four-factor reprogramming efficiency of mouse GFs was more than 7-fold higher than that of fibroblasts from tail-tips, possibly because of their high proliferative capacity.
CONCLUSIONS/SIGNIFICANCE: These results suggest that GFs from the easily obtainable gingival tissues can be readily reprogrammed into iPS cells, thus making them a promising cell source for investigating the basis of cellular reprogramming and pluripotency for future clinical applications. In addition, high-quality iPS cells were generated from mouse GFs without Myc transduction or a specific system for reprogrammed cell selection.
可从易得组织中高效生成诱导多能干细胞（iPS 细胞），具有临床应用的潜力。口腔牙龈在常规牙科治疗中经常被切除，被视为生物医学废物，但它是一种易于获取的组织，并且可以从患者身上分离出细胞，不会带来过多不适。
方法/主要发现：我们在此证明，通过引入四个因子（Oct3/4、Sox2、Klf4 和 c-Myc；GF-iPS-4F 细胞）或三个因子（与 GF-iPS-4F 细胞相同，但不包含 c-Myc 癌基因；GF-iPS-3F 细胞），可以不经过药物选择，从成年野生型小鼠牙龈成纤维细胞（GFs）中生成 iPS 细胞。还通过四因子转导从原代人牙龈成纤维细胞中生成 iPS 细胞。这些细胞表现出胚胎干细胞（ES 细胞）的形态和生长特性，并表达 ES 细胞标记基因，Nanog 和 Oct3/4 启动子区域的 CpG 甲基化比率降低。此外，畸胎瘤形成试验表明细胞具有 ES 细胞样分化，并代表所有三个胚层形成组织。与小鼠 GF-iPS-4F 细胞相比，GF-iPS-3F 细胞在 DNA 甲基化状态和基因表达方面表现出更具 ES 细胞样的特征，尽管重编程过程显著延迟，整体效率也降低。当移植到囊胚中时，GF-iPS-3F 细胞产生嵌合体，并有助于生殖系的发育。值得注意的是，与尾巴尖端的成纤维细胞相比，GF-iPS-4F 细胞的重编程效率提高了 7 倍以上，这可能是由于它们具有较高的增殖能力。
结论/意义：这些结果表明，从易于获得的牙龈组织中获取的 GFs 可以很容易地被重编程为 iPS 细胞，因此它们是一种很有前途的细胞来源，可以用于研究细胞重编程和多能性的基础，为未来的临床应用提供依据。此外，无需 Myc 转导或特定的重编程细胞选择系统，就可以从小鼠 GFs 中生成高质量的 iPS 细胞。
