权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulatory mechanisms of gene expression at mildly low temperature and the clinical relevance of their abnormality in the testis.

轻度低温下基因表达的调控机制及其睾丸异常的临床相关性。

基本信息

批准号：
16390463
负责人：
FUJITA Jun
金额：
$ 9.02万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16390463/
关键词：
stress gene physiology gene expression hypothermia apoptosis testis 遺伝子発現

项目摘要

In the mammalian testes, germ cells and somatic cells undergo active cell proliferation and differentiation at relatively low temperature (32-34℃). To elucidate how testicular cells adapt to the lower temperature and what biological significance it has, we have examined the regulatory mechanisms of gene expression and response to stressors at 32℃ in vitro.1.We identified several human genes whose expression was increased at 32℃.2."Mild cold response element" was determined in the 5' genomic sequence of Cirp (cold-inducible RNA-binding protein) gene.3.Within the Cirp mRNA, we identified the sequence that increased translation of Cirp and other heterologous mRNAs at 32℃.4.A subclohe of mouse BALB/3T3 fibroblasts resistant to low temperature and able to proliferate well at 32℃ was established.5.We found that mild hypothermia (32℃) suppressed induction of apoptosis by cytotoxic stimuli such as adriamycin, etoposide, thapsigargin, NaCl, H_2O_2, tumor necrosis factor (TNF)-α and anti-Fas antibody by various mechanisms. In adriamycin-treated BALB/3T3 cells, the down-shift in culture temperature increased the Bcl-xL protein level, and decreased the mRNA level of Puma and mitochondrial translocation of Bax, suppressing caspase-9-mediated apoptosis. These effects were mediated by suppression of the p53 pathway. In thapsigargin-treated cells, apoptosis was suppressed by p53-independent mechanisms. In cells treated with TNF-α and cycloheximide, apoptosis was suppressed, at least partly, via induction of Cirp that activated the ERK pathway.

在哺乳动物睾丸中，生殖细胞和体细胞在较低的温度（32-34℃）下进行活跃的细胞增殖和分化。为了阐明睾丸细胞如何适应较低的温度及其生物学意义，我们在体外研究了32℃条件下基因表达和应激反应的调控机制。我们发现了几个在32℃下表达增加的人类基因。在Cirp （cold-inducible RNA-binding protein，冷诱导rna结合蛋白）基因的5'基因组序列中确定了“轻度冷反应元件”。在Cirp mRNA中，我们发现了在32℃下增加Cirp和其他异源mRNA翻译的序列。建立了小鼠BALB/3T3成纤维细胞耐低温、在32℃下具有良好增殖能力的亚群。我们发现，亚低温（32℃）通过多种机制抑制阿霉素、依托opo苷、thapsigargin、NaCl、H_2O_2、肿瘤坏死因子(TNF)-α和抗fas抗体等细胞毒刺激诱导的细胞凋亡。在阿霉素处理的BALB/3T3细胞中，降低培养温度升高Bcl-xL蛋白水平，降低Puma mRNA水平和Bax线粒体易位，抑制caspase-9介导的细胞凋亡。这些作用是通过抑制p53通路介导的。在thapsigargin处理的细胞中，凋亡通过不依赖p53的机制被抑制。在TNF-α和环己亚胺处理的细胞中，细胞凋亡被抑制，至少部分是通过诱导激活ERK通路的Cirp。