Tomizawa Minoru, Shinozaki Fuminobu, Motoyoshi Yasufumi, Sugiyama Takao, Yamamoto Shigenori, Ishige Naoki
Minoru Tomizawa, Department of Gastroenterology, National Hospital Organization Shimoshizu Hospital, Yotsukaido City, Chiba 284-0003, Japan.
World J Methodol. 2015 Sep 26;5(3):108-14. doi: 10.5662/wjm.v5.i3.108.
Hepatic insufficiency is a fatal liver disease with a significant decrease in functioning hepatocytes. If hepatocytes could be generated from human induced pluripotent stem (hiPS) cells and transplanted into patients with hepatic insufficiency, the disease may become curable. However, a major limitation to this therapeutic strategy is due to the tumorigenicity of hiPS cells and their ability to form cancer. Current methods for eliminating unwanted hiPS cells use genetic manipulation or reagents that are potentially hazardous for hepatocytes; therefore, revised methods are necessary and anticipated. Glucose and arginine are essential cell culture medium ingredients for the survival of most cells, including hiPS cells. However, hepatocytes can produce its own glucose and arginine through galactokinase and ornithine transcarbamylase, respectively. Therefore, it was hypothesized that unwanted hiPS cells could be eliminated in a medium without glucose and arginine, and supplemented with galactose and ornithine instead. This modified medium has been established as hepatocyte selection medium (HSM). So far, attempts to generate a pure colony of mature hepatocytes from hiPS cells have not been successful. After establishment of co-culture in HSM, primary human hepatocytes survive while hiPS cells die within three days. Our latest results regarding a modification of HSM will be introduced in this manuscript.
肝衰竭是一种致命的肝脏疾病，其功能性肝细胞显著减少。如果能够从人诱导多能干细胞（hiPS细胞）生成肝细胞并移植到肝衰竭患者体内，该疾病或许有望治愈。然而，这一治疗策略的一个主要限制在于hiPS细胞的致瘤性及其形成肿瘤的能力。目前消除不需要的hiPS细胞的方法使用的是对肝细胞有潜在危害的基因操作或试剂；因此，需要并期待改进的方法。葡萄糖和精氨酸是包括hiPS细胞在内的大多数细胞存活所必需的细胞培养基成分。然而，肝细胞可以分别通过半乳糖激酶和鸟氨酸转氨甲酰酶产生自身的葡萄糖和精氨酸。因此，有人提出可以在不含葡萄糖和精氨酸、而是添加半乳糖和鸟氨酸的培养基中消除不需要的hiPS细胞。这种改良培养基已被确立为肝细胞选择培养基（HSM）。到目前为止，从hiPS细胞生成成熟肝细胞纯集落的尝试尚未成功。在HSM中建立共培养后，原代人肝细胞存活，而hiPS细胞在三天内死亡。本文将介绍我们关于HSM改良的最新结果。
