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

日本目前面临着前所未有的老龄化社会。在这种情况下，实现理想的再生医学对提高人类的福利和生活质量具有重要意义。为了满足这一社会需求，实现多种器官和组织的再生，获得稳定的多能干细胞供应源是至关重要的。如果真的能够用患者个体的体细胞再生各种器官和组织，那么它一定是一种理想的治疗方法，而不存在诸如使用ES细胞的伦理问题、器官移植中免疫反应的生物学限制以及人造器官的耐久性不足等问题。本研究从这一角度出发，探讨了骨髓基质和外周血中存在体干细胞的可能性，并尝试从人骨髓基质和外周血中分离体干细胞。还研究了这些细胞分化成各种细胞谱系的能力。本研究获得以下结果：1.建立了7株小鼠骨髓基质细胞系。通过逆转录-聚合酶反应和免疫细胞化学证实其中至少两种细胞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）。3.从人外周血中分离出多个成纤维细胞克隆，其中部分克隆无明显表型，增殖活性稳定。

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.