Abstract: Cerebral small vessel disease is a major vascular contributor to cognitive impairment and dementia. However, there remains a lack of effective preventative or therapeutic regimens for cerebral small vessel disease. In this study, we investigated the potential therapeutic effects of MCC950, a selective NOD-like receptor family pyrin domain-containing protein 3 inhibitor, on cerebral small vessel disease pathogenesis and cognitive decline in spontaneously hypertensive rats. Our results showed that chronic administration of MCC950 (10 mg/kg) to spontaneously hypertensive rats inhibited NOD-like receptor family pyrin domain-containing protein 3 inflammasome activation, thereby considerably suppressing the production of pyroptosis executive protein gasdermin D and pro-inflammatory factors, including interleukin-1β and -18. A decrease in astrocytic and microglial activation was also observed. We also found that MCC950 significantly inhibited autophagy. More importantly, behavioral assessment indicated that MCC950 administration ameliorated impaired neurocognitive function, which was associated with improvements in neuropathological hallmarks in the cerebral small vessel disease brain, such as blood‒brain barrier breakdown, white matter damage, and endothelial dysfunction. Thus, our findings revealed that the NOD-like receptor family pyrin domain-containing protein 3 inflammasome is a key contributor to the onset or progression of cerebral small vessel disease and suggested the potential of NOD-like receptor family pyrin domain-containing protein 3-based therapy as a potential novel strategy for treating cerebral small vessel disease.

Key words: astrocyte, autophagy, blood–brain barrier, cerebral small vessel disease, cognitive function, endothelial cells, microglia, neuroinflammation, NLRP3 inflammasome, white matter