Proper immune function is critical in nearly every aspect of mammalian physiology and disease. To defend the host, immune cells must rapidly transition from a quiescent to activated state in response to infections and other perturbations. In contrast, aberrant immune responses, e.g. excessive inflammation in cancer, metabolic syndrome, and autoimmune disorders, can result in damage to host and progression or exacerbation of disease states. Despite our basic knowledge of the immune system, our understanding of the critical metabolic and signaling pathways that regulate immune function remains incomplete. In my talk, I will describe our efforts aimed at integrating activity-based protein profiling (ABPP) with functional proteomic/metabolomics methods to map novel bioactive lipid networks involved in inflammation. I will describe the discovery and optimization of the first selective and in vivo-active small-molecule inhibitors for the putative 2-arachidonoylglycerol (2-AG) biosynthetic enzyme, diacylglycerol lipase-beta (DAGLB), along with paired negative-control and tailored activity-based probes for the functional analysis of DAGLB in living systems. We utilize our newly developed chemical probes to discover and show that DAGLB inactivation lowers 2-AG production in mouse peritoneal macrophages, as well as arachidonic acid and eicosanoids in a manner that is distinct and complementary to classical phospholipase A2-mediated pathways. A corresponding reduction in lipopolysaccharide (LPS)-induced TNF-alpha release was observed, indicating that DAGLB serves as a key metabolic hub within a lipid-signaling network that regulates proinflammatory responses in macrophages.
Michele Yager 404-894-8222