The Selective NLRP3-inflammasome inhibitor MCC950 Mitigates Post-resuscitation Myocardial Dysfunction and Improves Survival in a Rat Model of Cardiac Arrest and Resuscitation.

ABSTRACT

PURPOSE: To investigate the effects of the selective NLRP3 inflammasome inhibitor MCC950 on post-resuscitation myocardial function and survival in a rat model of cardiopulmonary resuscitation (CPR). METHODS: Thirty-six Sprague Dawley rats were randomized into three groups (1) MCC950, (2) control, and (3) sham. Each group consisted of a 6 h non-survival subgroup (n = 6) and a 48 h survival subgroup (n = 6). Ventricular fibrillation (VF) was induced and untreated for 6 min. CPR was initiated and continued for 8 min. Resuscitation was attempted with a 4 J defibrillation. MCC950 (10 mg/kg) or vehicle was administered via intraperitoneal injection immediately after the return of spontaneous circulation (ROSC). Myocardial function and sublingual microcirculation were measured after ROSC in the non-survival subgroups. Plasma levels of interleukin Iß (IL-1ß) and cardiac troponin I (cTnI) were measured at baseline and 6 h in the non-survival subgroups. Heart tissue was harvested to measure the NLRP3 inflammasome constituents, including NLRP3, apoptosis-associated speck-like protein (ASC), Caspase-1, and IL-1ß. Survival duration and neurologic deficit score (NDS) were recorded and evaluated among survival groups. RESULTS: Post-resuscitation myocardial function and sublingual microcirculation were improved in MCC950 compared with control (p < 0.05). IL-1ß and cTnI were decreased in MCC950 compared to control (p < 0.01). The MCC950 treated groups showed significantly reduced ASC, caspase-1, and IL-1ß compared with the control group (p < 0.05). Survival at 48 h after ROSC was greater in MCC950 (p < 0.05) with improved NDS (p < 0.05). CONCLUSION: Administration of MCC950 following ROSC mitigates post-resuscitation myocardial dysfunction and improves survival.