来自中科院动物研究所的段恩奎等人从小鼠真皮分离和鉴定了SKPs（皮肤干细胞），这一研究成果公布在Cell Proliferation 杂志上。
SKPs表达Nestin、Fibronectin、Stat3和Oct4等干细胞标记分子。SKPs能在体外扩增并稳定维持其干细胞特性，并能自发向神经细胞、平滑肌细胞和脂肪细胞分化。本研究首次在体外利用三步法诱导小鼠真皮干细胞分化为三维胰岛样集落（IPCs）。在Stage 1中，SKPs以悬浮的细胞球传代培养在DMEM/F12培养基（含有20 ng/ml表皮生长因子、40 ng/ml 碱性成纤维细胞生长因子、1% B27，培养基葡萄糖的浓度为17.3mM）。在Stage 2中，SKPs在DMEM/F12培养基（含有1 mM二丁酰环腺苷酸、1 μM维甲酸、1% B27 和2% FBS，培养基葡萄糖浓度为5mM）中培养2天，SKPs从细胞球中迁移出来形成单层细胞。在Stage 3中，细胞在DMEM/F12培养基（含有10 mM 烟酰胺、10 nM I型胰岛素样生长因子、2nM 激活素A、1% B27和2% FBS，培养基葡萄糖浓度为17.3mM）的中培养7天，细胞能够形成二硫腙阳性（Dithizone positive, DTZ+）的三维胰岛样集落（IPCs）。RT-PCR和间接免疫荧光的结果表明，IPCs共表达胰岛素和C-肽，并表达胰腺β细胞发育和功能相关的基因和转录因子，如Insulin 1、Insulin 2、Islet-1、Pdx-1、NeuroD/beta2、Glut-2 和 Nkx6.1，但不表达胰腺中其它的激素，如胰高血糖素、生长激素抑制素和淀粉酶。体外葡萄糖刺激的功能性实验结果表明，IPCs受葡萄糖浓度刺激而分泌胰岛素。（生物谷Bioon.com）
生物谷推荐原始出处：
Cell Proliferation Volume 42 Issue 1 DOI:10.1111/j.1365-2184.2008.00573.x
Efficient differentiation of insulin-producing cells from skin-derived stem cells
W. Guo*, C. Miao*, S. Liu*, Z. Qiu*, J. Li* and E. Duan*
*State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Chaoyang District, Beijing, China , and ?Graduate University of the Chinese Academy of Sciences, Shijingshan District, Beijing, China
Correspondence: E. Duan, State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang District, Beijing 100101, China. Tel.: +86 10 648 07308; Fax: +86 10 648 07186
ABSTRACT
Objectives: Type 1 diabetes mellitus, characterized by loss of pancreatic β-cells, can be ameliorated by islet transplantation, but this treatment is restricted by the scarcity of islet tissue and by allograft rejection.
Materials and Methods: We isolated and characterized skin-derived precursors (SKPs) – an abundant source of autologous cells – and developed an experimental strategy to convert them into insulin-producing cells (IPCs) in vitro within a short period of time, through extracellular factor modification and analyses of IPCs by reverse transcription–polymerase chain reaction, immunocytochemistry and enzyme-linked immunosorbent assay.
Results: SKPs could self-assemble to form three-dimensional islet cell-like clusters (dithizone-positive) and co-express insulin and C-peptide. In addition, they expressed multiple genes related to pancreatic β-cell development and function (e.g. insulin 1, insulin 2, islet-1, Pdx-1, NeuroD/beta2, glut-2 and Nkx6.1), but not other pancreas-specific hormones and enzymes (e.g. glucagon, somatostatin and amylase). Moreover, when stimulated with glucose, these cells synthesized and secreted insulin in a glucose-regulated manner.
Conclusions: The findings of this study indicate that SKPs can differentiate into functional IPCs and can provide an abundant source of autologous cells for transplantation. This study also provides strategies to derive autologous islet-replacement tissues from human skin stem cells.
