Tissue-ABPP enables high-resolution confocal fluorescence imaging of serine hydrolase activity in cryosections – Application to glioma brain unveils activity hotspots originating from tumor-associated neutrophils

摘要: Abstract Serine hydrolases (SHs) are a functionally diverse family of enzymes playing pivotal roles in health and disease have emerged as important therapeutic targets many clinical conditions. Activity-based protein profiling (ABPP) using fluorophosphonate (FP) probes has been powerful chemoproteomic approach studies unveiling SHs various biological systems. The ABPP utilizes cell/tissue proteomes features the FP warhead, linked to fluorescent reporter for in-gel fluorescence imaging or biotin tag streptavidin enrichment LC-MS/MS-based target identification. Here, we advance methodology glioma brain cryosections, enabling high-resolution confocal SH activity different cell types tumor microenvironment, identified by extensive immunohistochemistry on probe labeled sections. We name this technique tissue-ABPP distinguish it from conventional gel-based ABPP. show heightened vs. normal unveil hotspots originating tumor-associated neutrophils. Thorough optimization validation is provided parallel combined with verification. Tissue-ABPP enables wide range applications any type tissue animal species.