Imaging 26S proteasome activity and inhibition in living mice
Imaging 26S proteasome activity and inhibition in living mice
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DOI：
10.1038/nm894
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发表时间：
2003-07-01
期刊：
影响因子：
82.9
通讯作者：
Piwnica-Worms, D
中科院分区：
文献类型：
--
作者：
Luker, GD;Pica, CM;Piwnica-Worms, D
泛素-蛋白酶体途径是细胞中调节蛋白水解的中心介质，该途径的缺陷与癌症和神经退行性疾病有关。为了评估活体动物中的 26S 蛋白酶体功能，我们开发了一种用于生物发光成像的泛素荧光素酶报告基因。该报告基因在稳态条件下迅速降解，并以剂量和时间依赖性方式稳定响应蛋白酶体抑制剂。在使用一剂化疗蛋白酶体抑制剂硼替佐米 (PS-341) 后使用生物发光成像，肿瘤异种移植物中的蛋白酶体功能在 30 分钟内被阻断，并在 46 小时时恢复到接近基线。然而，经过两周的硼替佐米治疗后，目标肿瘤的成像显示蛋白酶体抑制显着增强，但不再恢复到基线。泛素荧光素酶报告基因能够对体内 26S 蛋白酶体活性进行重复的组织特异性分析，并有助于在小鼠模型中开发和验证蛋白酶体抑制剂，以及疾病发病机制中泛素蛋白酶体途径的研究。
The ubiquitin-proteasome pathway is the central mediator of regulated proteolysis in cells, and defects in this pathway are associated with cancer and neurodegenerative diseases. To assess 26S proteasome function in living animals, we developed a ubiquitin-luciferase reporter for bioluminescence imaging. The reporter was degraded rapidly under steady-state conditions and stabilized in a dose- and time-dependent manner in response to proteasome inhibitors. Using bioluminescence imaging after one dose of the chemotherapeutic proteasome inhibitor bortezomib (PS-341), proteasome function in tumor xenografts was blocked within 30 min and returned to nearly baseline by 46 h. After a 2-week regimen of bortezomib, however, imaging of target tumors showed significantly enhanced proteasome inhibition that no longer returned to baseline. The ubiquitin-luciferase reporter enables repetitive tissue-specific analysis of 26S proteasome activity in vivo and should facilitate development and validation of proteasome inhibitors in mouse models, as well as investigations of the ubiquitin-proteasome pathway in disease pathogenesis.