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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相对低温（32-34℃）下进行活跃的细胞增殖和分化。为了阐明睾丸细胞对低温的适应及其生物学意义，我们在体外研究了32 ℃下睾丸细胞基因表达和应激反应的调控机制。在Cirp的5'端基因组序列中确定了“轻度冷反应元件”（冷诱导RNA结合蛋白）基因。3.在Cirp mRNA中，4.建立了小鼠BALB/3 T3成纤维细胞耐低温亚群，并在32℃下增殖良好。细胞毒刺激物如阿霉素、足叶乙甙、毒胡萝卜素、NaCl、H_2O_2、肿瘤坏死因子（TNF-α）和抗Fas抗体等通过多种机制抑制细胞凋亡。在阿霉素处理的BALB/3 T3细胞中，培养温度的降低增加了Bcl-xL蛋白水平，降低了Puma的mRNA水平和Bax的线粒体易位，抑制了caspase-9介导的凋亡。这些作用是通过抑制p53通路介导的。在毒胡萝卜素处理的细胞中，细胞凋亡受到p53非依赖性机制的抑制。在用TNF-α和放线菌酮处理的细胞中，通过诱导Cirp激活ERK通路，细胞凋亡至少部分受到抑制。