Design, Synthesis, and Evaluation of Acrylamide Derivatives as Direct NLRP3 Inflammasome Inhibitors

NLRP3 inflammasome plays a key role in the intracellular activation of caspase-1, processing of pro-inflammatory interleukin-1β (IL-1β), and pyroptotic cell death cascade. NLRP3 overactivation is implicated in the pathogenesis of autoinflammatory diseases, known as cryopyrin-associated periodic syndromes (CAPS), and in the progression of several diseases, such as atherosclerosis, type-2 diabetes, gout, and Alzheimer’s disease. In this study, the synthesis of acrylamide derivatives and their pharmaco-toxicological evaluation as potential inhibitors of NLRP3-dependent events are described. Five hits were identified and evaluated for their efficiency in inhibiting IL-1β release from different macrophage subtypes, including CAPS mutant macrophages. Most attractive hits were tested for their ability to inhibit NLRP3 ATPase activity on human recombinant NLRP3. This screening allowed the identification of 14, 2-(2-chlorobenzyl)-N-(4-sulfamoylphenethyl)acrylamide, able to concentration-dependently inhibit NLRP3 ATPase with an IC50 of 74 µM. The putative binding pose of 14 in the ATPase domain of NLRP3 is also proposed