Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL, USA.
Cell Death Differ. 2010 Jun;17(6):1003-10. doi: 10.1038/cdd.2009.205. Epub 2010 Jan 8.
Apoptosis is a highly regulated process of programmed cell death essential for normal physiology. Dysregulation of apoptosis contributes to the development and progression of various diseases, including cancer, neurodegenerative disorders, and chronic heart failure. Quantitative noninvasive imaging of apoptosis in preclinical models would allow for dynamic longitudinal screening of compounds and facilitates a more rapid determination of therapeutic efficacy. In this study, we report the in vivo characterization of Z-DEVD-aminoluciferin, a modified firefly luciferase substrate that in apoptotic cells is cleaved by caspase-3 to liberate aminoluciferin, which can be consumed by luciferase to generate a luminescent signal. In two oncology models, namely SKOV3-luc and MDA-MB-231-luc-LN, at 24, 48, and 72 h after treatment with docetaxel, animals were injected with Z-DEVD-aminoluciferin and bioluminescent images were acquired. Significantly more light was detected at 24 (P<0.05), 48 (P<0.01), and 72 h (P<0.01) in the docetaxel-treated group compared with the vehicle-treated group, with caspase-3 activation at these time points confirmed using immunohistochemistry. Importantly, whereas significant differences between groups were detected as early as 24 h after treatment by molecular imaging, caliper measurements were unable to detect a difference for 4-5 additional days. Taken together, these data show that in vivo imaging of apoptosis using Z-DEVD-aminoluciferin could provide a sensitive and rapid method for early detection of drug efficacy, which could potentially be used by numerous therapeutic programs.
细胞凋亡是一种程序性细胞死亡的高度调控过程，对于正常生理学至关重要。细胞凋亡的失调导致了各种疾病的发展和进展，包括癌症、神经退行性疾病和慢性心力衰竭。在临床前模型中对细胞凋亡进行定量非侵入性成像，可以进行化合物的动态纵向筛选，并更快速地确定治疗效果。在这项研究中，我们报告了 Z-DEVD-aminoluciferin 的体内特征，这是一种经过修饰的萤火虫荧光素酶底物，在凋亡细胞中被 caspase-3 切割，释放出 aminoluciferin，它可以被荧光素酶消耗以产生发光信号。在两个肿瘤模型中，即 SKOV3-luc 和 MDA-MB-231-luc-LN，在紫杉醇治疗后 24、48 和 72 小时，动物被注射 Z-DEVD-aminoluciferin，并获取生物发光图像。与对照组相比，在紫杉醇治疗组中，在 24 小时（P<0.05）、48 小时（P<0.01）和 72 小时（P<0.01）时检测到的光显著增加，在这些时间点通过免疫组织化学证实了 caspase-3 的激活。重要的是，尽管通过分子成像在治疗后 24 小时就检测到了组间的显著差异，但卡尺测量在 4-5 天后仍无法检测到差异。总之，这些数据表明，使用 Z-DEVD-aminoluciferin 进行体内细胞凋亡成像可以提供一种敏感和快速的早期检测药物疗效的方法，这可能被许多治疗方案所采用。
