Isolation of somatic stem cells from bone marrow stroma and peripheral blood, and their application for tissue regeneration

今天的日本出现了前所未有的老龄化社会。在当前形势下，实现理想的再生医学对于提高人类福祉和生活质量具有十分重要的意义。为了满足这一社会需求，实现多种器官和组织的再生，确保稳定的多能干细胞供应来源至关重要。如果真能利用患者个体的体细胞再生各种器官和组织，就一定是不存在胚胎干细胞使用的伦理问题、器官移植中免疫反应的生物学局限性、人工器官耐久性不足等问题的理想治疗方法。从这个角度出发，本研究重点探讨了体细胞干细胞在骨髓基质和外周血中存在的可能性，并尝试从包括人在内的哺乳动物骨髓基质和外周血中分离体细胞干细胞。这些细胞分化成各种细胞系的能力也被研究。本研究提供了以下结果：1。建立了7株小鼠骨髓基质细胞株。通过逆转录聚合酶反应和免疫细胞化学，至少有两种细胞被证实能够分化为成骨细胞、软骨细胞和脂肪细胞（来源于中胚层）、神经细胞（来源于外胚层）和肝细胞（来源于内胚层）。由此证实，骨髓基质中含有三种胚层分化为功能细胞的干细胞。建立了使细胞分化为各细胞系的培养条件。从人外周血中分离出几个成纤维细胞克隆。其中一些无性系没有表现出显著的表型，并保持了恒定的增殖活性。

Japan sees unprecedented aging society today. In this present situation, it is very important for the improvement of human welfare anf quality of life to realize the ideal regenerative medicine. In order to meet such a social request and to achieve the regenerate a variety of organs and tissues, it is essential to secure the stabile source of supply of multipotent stem cells. If regeneration of various organs and tissues with somatic cells of patient individual is really enabled, it must be an ideal treatment without any problems such as ethical problem in using ES cells, biological limitations of immunereaction in organ transplantation, and insufficient durability of artificial organs. Fron this point of view, this research focused on the possibility of existence of somatic stem cells in bone marrow stroma and peripheral blood, and the isolation of somatic stem cells fron bone marrow stroma and peripheral blood of mammalians including human was attempted. The differentiation capacity of these cells into a variety of cell lineage was also investigated. The following results were provided by this study.1.Seven mouse bone marrow stromal cell lines were established. At least two of them wereconfirmed to be capable of differentiating into osteoblasts, chondrocytes and adipocytes (derived from mesoderm), neural cells (derived from ectoderm), and hepatocytes (derived from endoderm) by reverse transcription -polymerase reaction and immunocytochemistry. It was confirmed from these facts that bone marrow stroma contained stem cells which can differentiate into functional cells derived from three germ layers.2.The culture conditions which allow the cells to differentiate into each cell lineage were established.3.Several fibroblastic clones were isolated from human peripheral blood.4.Some of these clones exhibited no remarkable phenotype and maintained the constant proliferative activity.