Identification of genes regulating the differentiation of adrenocotical stem cells and their functional mechanisms

肾上腺干细胞分化调控基因的鉴定及其功能机制

基本信息

批准号：
10680675
负责人：
MITANI Fumiko
金额：
$ 2.18万
依托单位：
Keio Universsity
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Mammalian adrenal codex is composed of three zones, the zona glomerulosa (zG), zona fasciculata (zF), and zona reticularis (zR). Each zone has a different function, though cells in three zones are of the same origin, I.e. mesodermal origin. So far, stem cells and/or projenitor cells of the adrenal corex have not been identified, and molecular mechanisms of the differentiation, formation and maintenance of adrenal corex have remained obscure. We previously found a functionally undifferentiated cell zone (zU) between zG and zF in rats. Replicating cells in the cortex were abundant in and around zU, suggesting that zU contains stem cells which are capable to differentiate into zG or zF/zR cells. To develop in vitro model systems for analyzing the differentiation processes, we attempted to obtain adrenocodical cell lines at the undifferentiated stage similar to that of zU cells. Cell lines with such properties were established from a primary culture of adrenal glands from transgenic mice harboring a temperature sensitive mutant of SV40 large T antigen gene. Then, we tried to clone cDNAs encoding proteins which were expressed specifically in the undifferentiated cell lines with the aid of differential hybridization screening. Several cDNA clones were isolated. One of the cDNA clones was found to presumably encode a new extracellular matrix protein. Another cDNA encoded a new protein whose amino acid sequence did not have any known homologous sequence. Their mRNAs were detected in the regions from zG to zU and from zU to zF, respectively. The sites of their expression corresponded to the regions where cell proliferation and differentiation of the adrenocodical cells took place most actively.These results suggest that the newly discovered proteins expressing specifically in the undifferentiated cell lines have roles in the differentiation of adrenocortical cells and also in the formation of the adrenal cortex.

哺乳动物肾上腺法典由三个区域，Zona glomerulosa（ZG），Zona fasciculata（ZF）和Zona Reticularis（ZR）组成。每个区域具有不同的功能，尽管三个区域中的细胞具有相同的来源，即中胚层。到目前为止，尚未鉴定出肾上腺核心的干细胞和/或促剂细胞，并且肾上腺核心的分化，形成和维持的分子机制仍然晦涩难懂。我们先前在大鼠的ZG和ZF之间发现了功能分化的细胞区（ZU）。在ZU中及其周围，皮质中的复制细胞丰富，这表明ZU含有能够区分ZG或ZF/ZR细胞的干细胞。为了开发用于分析分化过程的体外模型系统，我们试图在类似于ZU细胞的未分化阶段获得腺苷细胞系。具有这种特性的细胞系是从具有SV40大T抗原基因温度敏感突变体的转基因小鼠的肾上腺原发性培养物中建立的。然后，我们试图克隆编码蛋白质的cDNA，这些蛋白质在差异杂交筛选的帮助下在未分化的细胞系中特别表达。分离了几个cDNA克隆。发现其中一个cDNA克隆可能编码了新的细胞外基质蛋白。另一个cDNA编码了一种新蛋白，其氨基酸序列没有任何已知的同源序列。在从ZG到ZU以及从ZU到ZF的区域中检测到它们的mRNA。它们表达的位点对应于肾上腺素细胞的细胞增殖和分化的区域。这些结果表明，这些结果表明，在未分化的细胞系中，新发现的新发现的蛋白质在非肾脏细胞的分化中具有作用，在肾上腺皮质的形成中也具有作用。