New fluorescent probe with recognition moiety of bipiperidinyl reveals the rise of hepatocellular carboxylesterase activity during heat shock

Heat shock is a heat-related pathology characterized by a high body temperature and an obvious change of many enzymatic activities. Carboxylesterase (CE), as the major hydrolase in liver, is responsible for the hydrolysis of many drugs or the detoxification of various toxins from all organs. However, the correlation between heat shock and the CE activity in cells remains unknown, mainly due to the lack of a suitable research approach. Herein, a new water-soluble fluorescence probe, MYO-CE, with a specific bipiperidinyl recognition moiety has been developed for detecting the CE activity. MYO-CE reacted selectively with CE instead of other esterase, causing a large fluorescence off-on response at 560 nm with a detection limit of 0.39 U/mL. The applicability of MYO-CE for cell imaging was demonstrated by monitoring the alteration of the hepatocellular CE activity under inflammation. More importantly, we investigated the change of the CE activity during heat shock, uncovering a significant increase for the first time. This finding was further validated by a commercial colorimetric kit assay. The proposed probe shows a promising prospect for the CE study in cells under different pathological conditions.