Exploring butyrylcholinesterase expression in living cells and diabetic mouse models using a fluorescent probe with near-infrared excitation and emission maxima

Butyrylcholinesterase (BChE), as a member of the cholinesterase family, is widely expressed in various tissues and cell types. Abnormal activity levels of BChE in organ systems or cells are usually associated with diseases. Therefore, developing effective methods for monitoring the distribution and activity of BChE in vivo is significant for exploring the physiological effects of BChE in organisms and improving prophylaxis, diagnosis or therapy of diseases. In this study, a dihydroxanthene-derived fluorescent probe CHQ-B with near-infrared (NIR) excitation and emission maxima was developed for visualizing endogenous BChE in vivo. This probe exhibits superior selectivity and sensitivity towards BChE, as well as low cytotoxicity and good biocompatibility to biosamples. Furthermore, efficient and robust fluorescence imaging of the distribution and activity of BChE in diabetic mouse models confirmed the high expression of BChE induced by diabetes. Results of experiments demonstrated that CHQ-B is a promising fluorescence imaging tool for exploring butyrylcholinesterase expression in organisms during researches of relationships between BChE expression and various diseases.