Modulation of Interleukin-1 and -18 Mediated Injury in Donation after Circulatory Death Mouse Hearts.

BACKGROUND: Donation after circulatory death donors (DCD) can expand the donor pool for heart transplantation, which primarily depends on brain death donors. Ischemia and reperfusion injury are inherent to the DCD process. We hypothesize that pharmacologic inhibition of interleukin-1 (IL-1) and/or IL-18 is protective to DCD hearts. MATERIALS AND METHODS: Following clinical protocol, in-situ ischemia time in control beating-heart donor (CBD) and DCD groups was less than 5 and 40 min, respectively. Wild type (WT) C57Bl6/j, IL-1 receptor type I knockout (IL-1RI-KO), and IL-18 KO mice were used. Hearts were reanimated for 90 min on a Langendorff system with Krebs-Henseleit buffer at 37°C, to assess physiologic parameters. Recombinant IL-1 receptor antagonist (IL-1Ra) and/or IL-18 binding protein (IL-18BP) were added to the Krebs-Henseleit buffer to inhibit IL-1 and/or the IL-18 signaling, respectively. RESULTS: Developed pressure and ± dP/dt were significantly impaired in the DCD-WT group compared to CBD-WT (P ≤ 0.05). Troponin release was higher in DCD-WT groups. Functional parameters were preserved, and troponin release was significantly less in the DCD knockout groups. Heart function was improved in DCD groups treated with IL-1Ra or IL-18BP compared to the DCD-WT group. CONCLUSIONS: Heart function was significantly impaired in the DCD-WT group compared to CBD-WT. Genetic deletion or pharmacologic blockade of IL-1 or IL-18 was protective to DCD hearts.

Structural Insights of Benzenesulfonamide Analogues as NLRP3 Inflammasome Inhibitors: Design, Synthesis, and Biological Characterization.

NLRP3 inflammasome plays critical roles in a variety of human diseases and represents a promising drug target. In this study, we established the in vivo functional activities of JC124, a previously identified NLRP3 inflammasome inhibitor from our group, in mouse models of Alzheimer's disease and acute myocardial infarction. To understand the chemical space of this lead structure, a series of analogues were designed, synthesized, and biologically characterized. The results revealed the critical roles of the two substituents on the benzamide moiety of JC124. On the other hand, modifications on the sulfonamide moiety of JC124 are well tolerated. Two new lead compounds, 14 and 17, were identified with improved inhibitory potency (IC50 values of 0.55 ± 0.091 and 0.42 ± 0.080 µM, respectively). Further characterization confirmed their selectivity and in vivo target engagement. Collectively, the results strongly encourage further development of more potent analogues based on this chemical scaffold.