• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Genome Integrity >Image-based quantitative determination of DNA damage signal reveals a threshold for G2 checkpoint activation in response to ionizing radiation
【24h】

Image-based quantitative determination of DNA damage signal reveals a threshold for G2 checkpoint activation in response to ionizing radiation

机译：基于图像的DNA损伤信号定量测定揭示了响应电离辐射的G2检查点激活的阈值

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Background Proteins involved in the DNA damage response accumulate as microscopically-visible nuclear foci on the chromatin flanking DNA double-strand breaks (DSBs). As growth of ionizing radiation (IR)-induced foci amplifies the ATM-dependent DNA damage signal, the formation of discrete foci plays a crucial role in cell cycle checkpoint activation, especially in cells exposed to lower doses of IR. However, there is no quantitative parameter for the foci which considers both the number and their size. Therefore, we have developed a novel parameter for DNA damage signal based on the image analysis of the foci and quantified the amount of the signal sufficient for G2 arrest. Results The parameter that we have developed here was designated as SOID. SOID is an abbreviation of Sum Of Integrated Density, which represents the sum of fluorescence of each focus within one nucleus. The SOID was calculated for individual nucleus as the sum of (area (total pixel numbers) of each focus) x (mean fluorescence intensity per pixel of each focus). Therefore, the SOID accounts for the number, size, and fluorescence density of IR-induced foci, and the parameter reflects the flux of DNA damage signal much more accurately than foci number. Using very low doses of X-rays, we performed a "two-way" comparison of SOID of Ser139-phosphorylated histone H2AX foci between G2-arrested cells and mitosis-progressing cells, and between mitosis-progressing cells in the presence or absence of ATM or Chk1/2 inhibitor, both of which abrogate IR-induced G2/M checkpoint. The analysis revealed that there was a threshold of DNA damage signal for G2 arrest, which was around 4000~5000 SOID. G2 cells with Conclusions We developed a novel parameter for quantitative analysis of DNA damage signal, and we determined the threshold of DNA damage signal for IR-induced G2 arrest, which was represented by 4000~5000 SOID. The present study emphasizes that not only the foci number but also the size of the foci must be taken into consideration for the proper quantification of DNA damage signal.
机译：背景参与DNA损伤反应的蛋白质在染色质侧翼DNA双链断裂（DSB）上以显微镜下可见的核焦点形式聚集。随着电离辐射（IR）诱导的病灶的生长放大了ATM依赖性DNA损伤信号，离散病灶的形成在细胞周期检查点激活中起着至关重要的作用，尤其是在暴露于较低剂量IR下的细胞中。但是，没有针对焦点的定量参数，该参数同时考虑了数量和大小。因此，我们基于病灶的图像分析开发了一种新的DNA损伤信号参数，并量化了足以阻止G2的信号量。结果我们在这里开发的参数称为SOID。 SOID是“ Integrated Density”（总密度）的缩写，表示一个核内每个焦点的荧光之和。计算每个原子核的SOID为（每个焦点的面积（总像素数））x（每个焦点的每个像素的平均荧光强度）之和。因此，SOID解释了IR诱导病灶的数量，大小和荧光密度，并且该参数比病灶数更准确地反映了DNA损伤信号的通量。使用非常低剂量的X射线，我们对G2阻滞细胞与有丝分裂进行性细胞之间以及有或没有丝裂的有丝分裂进行性细胞之间的Ser139磷酸化组蛋白H2AX病灶的SOID进行了“双向”比较。 ATM或Chk1 / 2抑制剂，两者均取消了IR诱导的G2 / M检查点。分析表明，存在G2停滞的DNA损伤信号阈值，约为4000〜5000 SOID。结论G2细胞的建立为定量分析DNA损伤信号建立了新的参数，并确定了IR诱导的G2阻滞的DNA损伤信号阈值，以4000〜5000 SOID表示。本研究强调，对于DNA损伤信号的正确定量，不仅必须考虑病灶数目，而且还必须考虑病灶的大小。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号