Background The formation of the NLRP3 inflammasome in the heart during AMI amplifies the inflammatory response and mediates further damage. Glyburide has NLRP3-inhibitory activity in vitro, but requires very high doses in vivo, associated with hypoglycemia. The aim of this study was to measure the effects on the NLRP3 inflammasome of 16673-34-0, an intermediate substrate free of the cyclohexylurea moiety, involved in insulin release. Methods and Results We synthetized 16673-34-0 (5-Chloro-2-methoxy-N-[2-(4-sulfamoylphenyl)ethyl]benzamide) that displayed no effect on glucose metabolism. HL-1 cardiomyocytes were treated with LPS+ATP to induce the formation of the NLRP3 inflammasome measured as increased caspase-1 activity and cell death, and 16673-34-0 prevented such effects. 16673-34-0 was well tolerated with no effects on the glucose levels in vivo. Treatment with 16673-34-0 in a model of AMI due to ischemia+reperfusion significantly inhibited the activity of inflammasome (caspase-1) in the heart by 90% (P<0.01) and reduced infarct size, measured at pathology (by >40%, P<0.01) and with troponin I levels (by >70%, P<0.01). Conclusions The small molecule 16673-34-0, an intermediate substrate in the glyburide synthesis free of the cyclohexylurea moiety, inhibits the formation of the NLRP3 inflammasome in cardiomyocytes and limits the infarct size following myocardial ischemia/reperfusion in the mouse, without affecting glucose metabolism.

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Background Sterile inflammation resulting from myocardial injury activates the NLRP3 inflammasome and amplifies the inflammatory response mediating further damage. Methods We used two experimental models of ischemic injury (acute myocardial infarction [AMI] with and without reperfusion) and a model of non-ischemic injury due to doxorubicin 10 mg/Kg, to determine whether the NLRP3 inflammasome preserved cardiac function after injury. Results Treatment with the NLRP3 inflammasome inhibitor in the reperfused AMI model caused a significant reduction in infarct size measured at pathology or as serum cardiac troponin I level (−56% and −82% respectively, both p<0.001), and preserved LV fractional shortening (LVFS, 31±2 vs vehicle 26±1%, p=0.003). In the non-reperfused AMI model treatment with the NLRP3 inhibitor significantly limited LV systolic dysfunction at 7 days (LVFS of 20±2 vs 14±1%, p=0.002), without a significant effect on infarct size. In the DOX model, a significant increase in myocardial interstitial fibrosis and a decline in systolic function were seen in vehicle-treated mice, whereas treatment with the NLRP3 inhibitor significantly reduced fibrosis (−80%, p=0.001) and preserved systolic function (LVFS 35±2 vs vehicle 27±2%, p=0.017). Conclusion Pharmacological inhibition of the NLRP3 inflammasome limits cell death and LV systolic dysfunction following ischemic and non-ischemic injury in the mouse.

The activation of the NLRP3 inflammasome signaling pathway plays an important role in the neuroinflammation in Alzheimer’s disease (AD). In this study, we investigated the effects of JC-124, a rationally designed NLRP3 inflammasome inhibitor, on AD-related deficits in CRND8 APP transgenic mice (TgCRND8). We first demonstrated increased formation and activation of NLRP3 inflammasome in TgCRND8 mice compared to non-transgenic littermate controls, which was inhibited by the treatment with JC-124. Importantly, JC-124 treatment led to decreased levels of Aβ deposition and decreased levels of soluble and insoluble Aβ1–42 in the brain of CRND8 mice which was accompanied by reduced β-cleavage of APP, reduced activation of microglia but enhanced astrocytosis. Oxidative stress was decreased and synaptophysin was increased in the CRND8 mice after JC-124 treatment, demonstrating a neuroprotective effect. Overall, these data demonstrated beneficial effects of JC-124 as a specific NLRP3 inflammasome inhibitor in AD mouse model and supported the further development of NLRP3 inflammasome inhibitors as a viable option for AD therapeutics.