Oishi Koichi, Noguchi Hirofumi, Yukawa Hiroshi, Hayashi Shuji
Department of Advanced Medicine in Biotechnology and Robotics, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Cell Transplant. 2009;18(5):581-9. doi: 10.1177/096368970901805-614.
Somatic stem cells can be isolated from a variety of sources. Although some studies have suggested that somatic stem cells may represent a cell population that is very similar to embryonic stem (ES) cells, it remains unclear whether somatic stem cells retain the potential to differentiate into any cell type derived from the three germ layers. In this study, we investigated the transdifferentiation potential of somatic stem cells using adipose tissue-derived stem/progenitor cells (ASCs; mesodermal stem cells) and pancreatic stem cells (endodermal stem cells). Previous reports from other groups describe the protocol that has been used to differentiate ASCs or mesenchymal stem cells (MSCs) in bone marrow into insulin-producing cells. Induction 1: ASCs were cultured for 3 days in ultra-low attachment plates under serum-free conditions. Induction 2: ASCs were cultured for 24 h with L-DMEM, and reinduced with serum-free H-DMEM for another 10 h. Unlike previous reports, we did not get ASCs to express any pancreas-specific genes, including insulin-1 or insulin-2. Pancreatic stem cells were induced to differentiate into adipo/osteogenic by the following protocols. Induction protocol 1: ACSs were cultured for 7 days with medium containing indometacin, dexamethasone, hydrocortisone, and insulin for adipogenic differentiation. Induction protocol 2: The cells were cultured for 7 days with medium containing dexamethasone, ascorbate-2-phosphate, and beta-glycerophosphate for osteogenic differentiation. Although these approaches have been widely used for adipo/osteogenic differentiation from MSCs, adipo/osteogenic differentiation from pancreatic stem cells was not observed. These data suggest that it is not easy for somatic stem cells to transdifferentiate into other germ cell types, at least, under these conditions.
体干细胞可从多种来源分离得到。尽管一些研究表明体干细胞可能代表一种与胚胎干细胞（ES细胞）非常相似的细胞群体，但体干细胞是否保留分化为源自三个胚层的任何细胞类型的潜力仍不清楚。在本研究中，我们使用脂肪组织来源的干/祖细胞（ASC；中胚层干细胞）和胰腺干细胞（内胚层干细胞）研究了体干细胞的转分化潜力。其他研究小组之前的报告描述了用于将骨髓中的ASC或间充质干细胞（MSC）分化为胰岛素产生细胞的方案。诱导1：ASC在无血清条件下于超低附着板中培养3天。诱导2：ASC用L-DMEM培养24小时，然后用无血清H-DMEM再诱导10小时。与之前的报告不同，我们没有使ASC表达任何胰腺特异性基因，包括胰岛素-1或胰岛素-2。胰腺干细胞通过以下方案被诱导分化为脂肪/成骨细胞。诱导方案1：ASC在含有吲哚美辛、地塞米松、氢化可的松和胰岛素的培养基中培养7天以进行脂肪生成分化。诱导方案2：细胞在含有地塞米松、抗坏血酸-2-磷酸和β-甘油磷酸的培养基中培养7天以进行成骨分化。尽管这些方法已被广泛用于MSC的脂肪/成骨分化，但未观察到胰腺干细胞的脂肪/成骨分化。这些数据表明，至少在这些条件下，体干细胞不容易转分化为其他胚层细胞类型。
