Vol13-1-e47

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15AIST TODAY 2013-1life-liaison-ml@aist.go.jpFor inquiries about this article : Research Planning Office of Life Science and Blotechnologylabor is involved in handling these cells. What is worse, iPS and ES cells have highly unstable nature. Particularly when there is a deviation in the subculture method, they instantly undergo rapid denaturation and are no longer suitable for regenerative medicine. Further, the method of culture slightly varies from one set of iPS or ES cells to another (composition of the medium, subculture method, etc.). Without solving these problems, we cannot realize mass production of standardized cell products. And without mass production, practical application in society will not be realized.Solving problems to establish an evaluation infrastructure technologyUnder these circumstances, we developed an automatic cell culture equipment, called AutocultureⓇ, in a NEDO project together with Kawasaki Heavy Industries, Ltd. and the National Center for Child Health and Development. This equipment successfully incorporates a proven culture technique for these cells, which may be considered to be an “art” (Fig. 2a). Autoculture has a sterile housing, in which a robot arm conducts culture operations. Inside the housing are installed an incubator and a refrigerator, allowing operation without the need for refilling for about a week. Once the type of cell is designated, the equipment conducts individual culture operations according to the protocol installed in the equipment. When alkaline phosphatase (AP) staining of a colony of cells under continuous culture was conducted (which dyes the cells red if they are not yet differentiated), it was confirmed that an undifferentiation rate of about 98 % was maintained. Using this equipment, more than 20 passages of continuous culture were successfully conducted (Fig. 2b). This technological feat that realizes stable culture has now almost enabled us to mass-produce “uniform” iPS cells. We intend to organize stem cell evaluation items based on a large amount of the produced samples and establish a system that fully allows us to stably provide standardized stem cell products to the clinical sites of regenerative medicine and pharmaceutical companies.human tissue cells such as liver, heart, and pancreas cells from the cells easily obtained. Although researchers found the evidences suggesting this idea more than forty years ago, it has remained a dream despite strenuous investigation.Impact of discovery of iPS cellsHuman embryonic stem (ES) cells capable of differentiating into various tissue cells were first generated in 1998. These pluripotent cells are potentially useful, but have a serious ethical problem that they are generated by destroying normal human embryos which may grow up to be individuals. Immunological rejection of ES-derived cells by recipient patients is another fundamental problem. Human induced pluripotent stem cells (iPS cells) were first generated in 2007 by reprogramming normal skin cells through ectopic expression of a defined number of genes. Development of iPS cells brought us closer to ideal regenerating medicine using patient-derived tissue cells, because the iPS cells are pluripotent and can become various tissue cells and, at the same time, the iPS-derived tissue cells will be transplantable without immunological rejection.Future of iPS cell technologyAfter the discovery of iPS cells, researchers also started to pursue the direct conversion of skin cells to various tissue cells Human cells in clinics and in industriesNormal human tissue cells are used widely in clinical medicine: e.g., in blood transfusion, in bone marrow transplantation, and in organ transplantation. Although autologous tissue cells are ideal source for these applications, it is difficult to obtain a sufficient number of tissue cells, except for those of blood and skin. Pharmaceutical companies also need large quantities of the normal human tissue cells. They have used various animal cells for examining safety and effectiveness of new drugs, while these substitutes do not necessarily reflect physiological functions of human cells. Therefore, it is desirable to generate large quantities of valuable Creating Stem Cells: Generation of High-Quality Human iPS Cells by Using RNA Virus Vector Organ Development Research TeamResearch Center for Stem Cell EngineeringYuzuru ITOUStem Cell Differentiation Research TeamResearch Center for Stem Cell EngineeringAkira KURISAKI

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