Therapeutic Potential of NLRP3 Inhibitor MCC950 in Aging Mice Stroke Outcomes

The inflammatory cascade worsens tissue injury and clinical outcomes in acute stroke. The NLRP3 inflammasome plays a central role in the innate immune system. Aged humans and mice exhibit chronic sterile inflammation, known as "inflammaging," characterized by activation of the innate immune system. Our central hypothesis is that inhibiting the NLRP3 inflammasome will improve long-term functional outcomes in aged mice subjected to middle cerebral artery occlusion. We aimed to investigate the long- and short-term effects of MCC950, an NLRP3- specific inhibitor, on stroke outcomes. In this study, 14-15-month-old C57BL/6 mice were subjected to middle cerebral artery occlusion (MCAO) under isoflurane anesthesia. Mice were treated with MCC950 (50 mg/kg, first day and then 10 mg/kg per day) or vehicle (i.p) up to 72 h in the short-term experiment. A 10 mg/kg (i.p) daily or vehicle for 28 days (5x/week) in the long-term experiment were given. Behavioral studies were performed at the end of each experimental set using the corner test, beam walk, hanging wire, Y maze, NOR test, and a battery of neurobehavioral tests. The mice were sacrificed, and the whole brain tissue was used to assess IL-1β, IL-18, TNFα, NLRP3, Caspase 1, and GSDMD expression by qPCR. NLRP3, Caspase 1, IL1β, IL18, Claudin5, occludin, Zona occludin (ZO1), and GSDMD were also estimated by Western blot assay. Histopathology was performed to assess the neuronal damage and white matter loss. MCC950 treatment in aging stroke mice attenuated inflammatory changes, BBB impairment, and rescued stroke-induced neurobehavioral impairment in acute as well as in chronic treatment. The infarction area was reduced in the short-term experiment. Our study suggests that MCC950 is a promising therapy for acute stroke.