In vivo inflammation imaging using a CB2R-targeted near infrared fluorescent probe

American Journal of Nuclear Medicine and Molecular Imaging

Ling Yang¹  Steve H Thorne¹  Pin Shao¹  Carolyn J Anderson¹  Mingfeng Bai¹  Weizhou Hou¹  Xiaoxi Ling¹  Shaojuan Zhang¹  Wissam Beaino¹  Ying Ding¹ 

关键词: Inflammation;    cannabinoid receptor;    CB2;    fluorescent probe;    optical imaging;    near infrared;   

DOI  :  

学科分类：过敏症与临床免疫学

来源: e-Century Publishing Corporation

【 摘 要 】

Chronic inflammation is considered as a critical cause of a host of disorders, such as cancer, rheumatoid arthritis, atherosclerosis, and neurodegenerative diseases, although the exact mechanism is yet to be explored. Imaging tools that can specifically target inflammation are therefore important to help reveal the role of inflammation in disease progression, and allows for developing new therapeutic strategies to ultimately improve patient care. The purpose of this study was to develop a new in vivo inflammation imaging approach by targeting the cannabinoid receptor type 2 (CB₂R), an emerging inflammation biomarker, using a unique near infrared (NIR) fluorescent probe. Herein, we report the first in vivo CB₂R-targeted NIR inflammation imaging study using a synthetic fluorescent probe developed in our laboratory, NIR760-mbc94. In vitro binding assay and fluorescence microscopy study indicate NIR760-mbc94 specifically binds towards CB₂R in mouse RAW264.7 macrophage cells. Furthermore, in vivo imaging was performed using a Complete Freund’s Adjuvant (CFA)-induced inflammation mouse model. NIR760-mbc94 successfully identified inflamed tissues and the probe uptake was blocked by a CB₂R ligand, SR144528. Additionally, immunofluorescence staining in cryosectioned tissues validated the NIR760-mbc94 uptake in inflamed tissues. In conclusion, this study reports the first in vivo CB₂R-targeted inflammation imaging using an NIR fluorescent probe. Specific targeting of NIR760-mbc94 has been demonstrated in macrophage cells, as well as a CFA-induced inflammation mouse model. The combined evidence indicates that NIR760-mbc94 is a promising inflammation imaging probe. Moreover, in vivo CB₂R-targeted fluorescence imaging may have potential in the study of inflammation-related diseases.

【 授权许可】

Unknown