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

• 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
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680675/
• 关键词: stem cell; functional zonation; adrenocortical zonation; undifferentiated cells; organogenesis; cell differentiation; steroid hormone; adrenal cortex

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.

哺乳动物肾上腺皮质由三个区带组成，即球状肾上腺皮质（zG）、束状肾上腺皮质（zF）和网状肾上腺皮质（zR）。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起源，即中胚层起源。到目前为止，肾上腺皮质的干细胞和/或祖细胞尚未得到鉴定，并且肾上腺皮质的分化、形成和维持的分子机制仍然不清楚。我们先前在大鼠中发现了zG和zF之间的功能未分化细胞带（zU）。皮层中的复制细胞在zU中及其周围丰富，表明zU含有能够分化为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，我们试图获得与zU细胞类似的处于未分化阶段的肾上腺皮质细胞系。具有这种特性的细胞系是从含有SV 40大T抗原基因的温度敏感突变体的转基因小鼠的肾上腺的原代培养物中建立的。然后，我们试图克隆的cDNA编码的蛋白质，在未分化的细胞系中特异性表达的帮助下，差异杂交筛选。分离了几个cDNA克隆。发现其中一个cDNA克隆可能编码一种新的细胞外基质蛋白。另一个cDNA编码一种新的蛋白质，其氨基酸序列没有任何已知的同源序列。它们的mRNA分别在zG至zU和zU至zF区域被检测到。结果表明，在未分化细胞系中特异性表达的蛋白质在肾上腺皮质细胞的分化和肾上腺皮质的形成中起作用。

项目成果

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Miyamoto H: "A Low-Sodium Diet Affects the Proliferation and Migration of Rat Adrenocortical Cells in vivo"Molecular Steroidogenesis(eds.M,Okamoto et al,Universal Academy Press). 227-228 (2000)

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Mitani, F.: "Development of Functional Zonation in the Rat Adrenal Cortex."Endocrinology. 140(7). 3342-3353 (1999)

Mitani, F.：“大鼠肾上腺皮质功能分区的发展。”内分泌学。

Mitani F: "Development of the Functional Zonation in the Rat Adennal Cortex"Endocrinology. 140-7. 3342-3353 (1999)

Mitani F：“大鼠腺皮质功能分区的发展”内分泌学。

Mitani,F.: "Localization of Replicating Cells in Rat Adrenal Cortex during the Late Gestational and Early Postnatal Stages." Endocrine Res.(in press). (1999)

Mitani,F.：“妊娠晚期和产后早期大鼠肾上腺皮质复制细胞的定位”。