Schwenck Johannes, Maier Florian C, Kneilling Manfred, Wiehr Stefan, Fuchs Kerstin
Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University of Tübingen; Department of Nuclear Medicine, Eberhard Karls University of Tübingen.
Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University of Tübingen.
J Vis Exp. 2017 May 8(123):55180. doi: 10.3791/55180.
This paper describes a non-invasive method for imaging matrix metalloproteinases (MMP)-activity by an activatable fluorescent probe, via in vivo fluorescence optical imaging (OI), in two different mouse models of inflammation: a rheumatoid arthritis (RA) and a contact hypersensitivity reaction (CHR) model. Light with a wavelength in the near infrared (NIR) window (650 - 950 nm) allows a deeper tissue penetration and minimal signal absorption compared to wavelengths below 650 nm. The major advantages using fluorescence OI is that it is cheap, fast and easy to implement in different animal models. Activatable fluorescent probes are optically silent in their inactivated states, but become highly fluorescent when activated by a protease. Activated MMPs lead to tissue destruction and play an important role for disease progression in delayed-type hypersensitivity reactions (DTHRs) such as RA and CHR. Furthermore, MMPs are the key proteases for cartilage and bone degradation and are induced by macrophages, fibroblasts and chondrocytes in response to pro-inflammatory cytokines. Here we use a probe that is activated by the key MMPs like MMP-2, -3, -9 and -13 and describe an imaging protocol for near infrared fluorescence OI of MMP activity in RA and control mice 6 days after disease induction as well as in mice with acute (1x challenge) and chronic (5x challenge) CHR on the right ear compared to healthy ears.
本文描述了一种通过可激活荧光探针，利用体内荧光光学成像（OI），在两种不同的炎症小鼠模型（类风湿性关节炎（RA）和接触性超敏反应（CHR）模型）中对基质金属蛋白酶（MMP）活性进行成像的非侵入性方法。与波长低于650nm的光相比，近红外（NIR）窗口（650 - 950nm）中的光能够实现更深的组织穿透且信号吸收最小。使用荧光OI的主要优点在于其成本低廉、速度快且易于在不同动物模型中实施。可激活荧光探针在其失活状态下光学上是沉默的，但在被蛋白酶激活时会变得高度荧光化。活化的MMP会导致组织破坏，并在诸如RA和CHR等迟发型超敏反应（DTHR）的疾病进展中发挥重要作用。此外，MMP是软骨和骨降解的关键蛋白酶，由巨噬细胞、成纤维细胞和软骨细胞响应促炎细胞因子而诱导产生。在这里，我们使用一种被关键MMP（如MMP - 2、- 3、- 9和- 13）激活的探针，并描述了一种成像方案，用于在疾病诱导6天后对RA和对照小鼠以及与健康耳朵相比右耳有急性（1次激发）和慢性（5次激发）CHR的小鼠进行MMP活性的近红外荧光OI成像。
