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Mechanisms controlling stabilization of differentiation and transdifferentiation in the animal tissue cell.

控制动物组织细胞分化和转分化稳定的机制。

基本信息

批准号：
04404004
负责人：
EGUCHI Goro
金额：
$ 10.24万
依托单位：
National Institute for Basic Biology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

Through studies for three fiscal years from 1992 to 1994, the following results were obtained.1.A gene encoding TGFbeta-binding protein, which is expressed by chicken retinal pigmented epithelial cells (RPECs), produces 5.0kb and 6.0kb mRNAs by alternative splicing. The 5.0kb mRNA product is secreted and the 6.0kb mRNA product binds to extracellular matrix (ECM) of RPECs. Both products regulate the cell state and transdifferentiation of RPECs in vitro through modulating function of TGFbeta secreted by RPECs themselves. It has been also found that bFGF is one of major factors regulating RPECs in their expre-ssion of TGFbeta and its binding protein. In addition, a nobel serine-protease inhibitor has been found to be specifically expressed by RPECs and play essential roles in functional differentiation and maintenance of function of this cell type. 2. In addition to the fact that mature human RPECs can readily transdiffe-rentiate into lens cells when dissociated and cultured, it has been clealy demonstrated that a clonal cell line derived from 80-year-old human RPECs can express neurofilament protein submits to trans-differentiate into neuronal phenotypes. This result is the first evidence that the RPEC of even mature human can spontaneously transdifferentiate into neuronal cells under adequate conditions. 3. It has been found that the RPECs are very sensitive against cell culture condition, particularly serum added to the culture media. Through detailed comparison between RPECs and iris pigmented epithelial cells (IPECs) in culture, IPECs is much less sensitive and can be stably maintained in vitro. Based on this finding, much more powerful cell culture system of lens transdifferentiation has been established using one-day-old chicken IPECs. This system must contribute to future progress of our studies on transdifferentiation.

通过1992 ~ 1994年三个财政年度的研究，获得以下结果：1.鸡视网膜色素上皮细胞（RPECs）表达的TGF β结合蛋白基因通过选择性剪接产生5.0kb和6.0kb的mRNA。5.0kb的mRNA产物被分泌，并且6.0kb的mRNA产物与RPEC的细胞外基质（ECM）结合。这两种产物通过调节RPEC自身分泌的TGF β的功能来调节RPEC的细胞状态和体外转分化。bFGF是调节RPEC表达TGF β及其结合蛋白的主要因素之一。此外，已发现一种诺贝尔丝氨酸蛋白酶抑制剂由RPEC特异性表达，并在该细胞类型的功能分化和功能维持中发挥重要作用。2.除了成熟的人RPEC在解离和培养时可以容易地转分化成透镜细胞的事实之外，已经清楚地证明，来自80岁的人RPEC的克隆细胞系可以表达神经丝蛋白，从而转分化成神经元表型。这一结果是第一个证据表明，即使是成熟的人的RPEC可以自发转分化为神经元细胞在适当的条件下。3.已经发现RPEC对细胞培养条件非常敏感，特别是添加到培养基中的血清。通过对体外培养的RPEC和虹膜色素上皮细胞（IPECs）的详细比较，IPECs的敏感性要低得多，并且可以在体外稳定地维持。在此基础上，利用1日龄鸡IPECs建立了更有效的透镜转分化细胞培养体系。该系统的建立必将为转分化研究的进一步发展做出贡献。