Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy.
Pharm Res. 2011 Nov;28(11):2820-32. doi: 10.1007/s11095-011-0552-0. Epub 2011 Aug 5.
To evaluate the utility of new Translocator protein 18 kDa (TSPO)-targeted fluorescent probes for in vivo molecular imaging of activated microglia.
Compounds 2-4 were synthesized; their stability and affinity for TSPO were determined. Compounds 2-4 were incubated both with Ra2 cells in the presence of LPS, a potent activator of microglia, and with tissue sections of normal and chemically injured brains. Compounds 2-4 were injected into carotid artery or directly in striatum of mice. Cells and tissue sections from these in vitro and in vivo studies were observed by fluorescence microscopy after histochemical treatments.
Compounds 2-4 are stable in both buffer and physiological medium and showed high affinity for TSPO and were found to stain live Ra2 microglial cells effectively. Double staining with Mito Tracker Red suggested that binding sites of compounds 2 and 3 may exist on mitochondria. In vivo studies showed that compounds 2-4 may penetrate in part into brain; moreover, cells in mouse striatum were stained with compounds 2-4 and microglial marker CD11b.
Compounds 2-4 can fluorescently label activated microglia in vitro and in vivo.
评估新型 18kDa 转位蛋白（TSPO）靶向荧光探针在激活的小胶质细胞体内分子成像中的应用。
合成了化合物 2-4；测定了它们的稳定性和对 TSPO 的亲和力。将化合物 2-4 与 LPS（一种强效的小胶质细胞激活剂）存在下的 Ra2 细胞以及正常和化学损伤脑的组织切片一起孵育。将化合物 2-4 注射到颈动脉或直接注射到小鼠纹状体中。对这些体外和体内研究的细胞和组织切片进行组织化学处理后，通过荧光显微镜进行观察。
化合物 2-4 在缓冲液和生理介质中均稳定，对 TSPO 具有高亲和力，并能有效染色活的 Ra2 小胶质细胞。与 MitoTracker Red 的双重染色表明，化合物 2 和 3 的结合位点可能存在于线粒体上。体内研究表明，化合物 2-4 可能部分穿透大脑；此外，用化合物 2-4 和小胶质细胞标志物 CD11b 对小鼠纹状体中的细胞进行了染色。
化合物 2-4 可在体外和体内荧光标记激活的小胶质细胞。
