Microglial Inflammasome Activation in Penetrating Ballistic-Like Brain Injury

Penetrating traumatic brain injury (PTBI) is a significant cause of death and disability in the United States. Inflammasomes are one of the key regulators of the interleukin (IL)-1β mediated inflammatory responses after traumatic brain injury (TBI). However, the contribution of inflammasome signaling after PTBI has not been determined. In this study, adult male Sprague-Dawley rats were subjected to sham procedures or penetrating ballistic-like brain injury (PBBI) and sacrificed at various time points. Tissues were assessed by immunoblot analysis for expression of IL-1β, IL-18 and components of the inflammasome: apoptosis-associated speck-like protein containing a caspase-activation and recruitment domain (ASC), caspase-1, X-linked inhibitor of apoptosis protein (XIAP), NOD-like receptor protein 3 (NLRP3), and gasdermin-D (GSDMD). Specific cell types expressing inflammasome proteins were also evaluated immunohistochemically and assessed quantitatively. After PBBI, expression of IL-1β, IL-18, caspase-1, ASC...