Pyroptosis plays a significant role in neuroinflammation after traumatic brain injury (TBI). However, the role of pyroptosis executor Gasdermin D (GSDMD) in neurological deficits and neuropathological alterations after TBI have not been elucidated. Our results demonstrated that GSDMD-KO exerted striking neuroprotective effects on motor dysfunction and neuropathological alterations (loss of synaptic proteins, microglia activation, astrogliosis, dendrite injury, and neuron death) at 3 days after TBI. GSDMD-KO inhibited the expression and release of pro-inflammatory cytokine releases (IL-1β and TNF-α) while promoting those of anti-inflammatory cytokines (IL-10 and TGF-β1). The temporal pattern of diverse inflammasome signals showed long-lasting elevations of NLRP3, caspase 1, and caspase 1 p20 after TBI, rather than NLRP1, NLRC4 or AIM2, similar to the change in GSDMD postinjury; and NLRP3-KO not only inhibited the expression and cleavage of GSDMD but also attenuated the loss of synaptic proteins and neurological deficits. Notably, RNA sequencing showed both GSDMD-KO and NLRP3-KO reversed the global expression of neuroinflammation- and neuropathology-related genes after TBI. Our findings proved that the inhibition of GSDMD exerts neuroprotective effects after TBI and is mainly driven by the NLRP3 inflammasome. GSDMD serves as a potent therapeutic target for the treatment of TBI.

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AimsAdenosine 2A receptor (A2AR) is widely expressed in the brain and plays important roles in neuroinflammation, and the nucleotide‐binding oligomerization domain, leucine‐rich repeat, and pyrin domain‐containing protein 3 (NLRP3) inflammasome is a crucial component of the innate immune system while the regulation of A2AR on it in the central nervous system (CNS) has not been clarified.MethodsThe effects of microglial A2AR on NLRP3 inflammasome assembly and activation were investigated in wild‐type, A2AR‐ or NLRP3‐knockout primary microglia with pharmacological treatment. Microglial A2AR or NLRP3 conditional knockout mice were used to interrogate the effects of this regulation on neuroinflammation posttraumatic brain injury (TBI).ResultsWe found that A2AR directly interacted with NLRP3 and facilitated NLRP3 inflammasome assembly and activation in primary microglia while having no effects on mRNA levels of inflammasome components. Inhibition of the interaction via A2AR agonist or knockout attenuated inflammasome assembly and activation in vitro. In the TBI model, microglial A2AR and NLRP3 were co‐expressed at high levels in microglia next to the peri‐injured cortex, and abrogating of this interaction by microglial NLRP3 or A2AR conditional knockout attenuated the neurological deficits and neuropathology post‐TBI via reducing the NLRP3 inflammasome activation.ConclusionOur results demonstrated that inhibition of the interaction between A2AR and NLRP3 in microglia could mitigate the NLRP3 inflammasome assembly and activation and ameliorate the neuroinflammation post‐TBI. It provides new insights into the effects of A2AR on neuroinflammation regulation post‐TBI and offers a potential target for the treatment of NLRP3 inflammasome‐related CNS diseases.

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