Probenecid-Blocked Pannexin-1 Channel Protects Against Early Brain Injury via Inhibiting Neuronal AIM2 Inflammasome Activation After Subarachnoid Hemorrhage

Abstract

AimPrevious studies have proved that inhibiting inflammasome activation provides neuroprotection against early brain injury (EBI) after subarachnoid hemorrhage (SAH), which is mainly focused on the microglial inflammatory response, but the potential role of neuronal inflammasome activation in EBI has not been clearly identified. This study examined whether the pannexin-1 channel inhibitor probenecid could reduce EBI after SAH by inhibiting neuronal AIM2 inflammasome activation.MethodsThere are in vivo and in vitro parts in this study. First, adult male SD rats were subjected to the endovascular perforation mode of SAH. The time course of pannexin-1 and AIM2 expressions were determined after SAH in 72 h. Brain water content, neurological function, AIM2 inflammasome activation, and inflammatory response were evaluated at 24 h after SAH in sham, SAH, and SAH + probenecid groups. In the in vitro part, HT22 cell treated with hemin was applied to mimic SAH. The expression of AIM2 inflammasome was detected by immunofluorescence staining. Neuronal death and mitochondrial dysfunction were determined by the LDH assay kit and JC-1 staining.ResultsThe pannexin-1 and AIM2 protein levels were upregulated after SAH. Pannexin-1 channel inhibitor probenecid attenuated brain edema and improved neurological dysfunction by reducing AIM2 inflammasome activation and reactive oxygen species (ROS) generation after SAH in rats. Treating HT22 cells with hemin for 12 h resulted in AIM2 and caspase-1 upregulation and increased mitochondrial dysfunction and neuronal cell death. Probenecid significantly attenuated the hemin-induced AIM2 inflammasome activation and neuronal death.ConclusionsAIM2 inflammasome is activated in neurons after SAH. Pharmacological inhibition of the pannexin-1 channel by probenecid attenuated SAH-induced AIM2 inflammasome activation and EBI in vivo and hemin-induced AIM2 inflammasome activation and neuronal death in vitro.

L-Carnitine augments probenecid anti-inflammatory effect in monoiodoacetate-induced knee osteoarthritis in rats: involvement of miRNA-373/P2X7/NLRP3/NF-κB milieu

“…It had been previously mentioned that probenecid therapy, protects against early brain injury after subarachnoid hemorrhage in rats via causing a marked reduction in the expression of P2X7R due to the inhibition of the pannexin-1 channel. Additionally, probenecid was able to reduce the production of inflammatory cytokines, prevent the activation of the AIM2 inflammasome, and enhance neurological functioning (Zheng et al 2022 ). In another study, probenecid protected the primary astrocytes from oxygen–glucose deprivation damage via modulating inflammasome activity (Jian et al 2016 ).…”

Serum levels of neurotensin, pannexin-1, and sestrin-2 and the correlations with sleep quality or/and cognitive function in the patients with chronic insomnia disorder

“…Pannexin-1 is found in neurons and various glial cells (astrocyte, microglia, oligodendrocytes), and the pathophysiological activity of pannexin-1 is highly related to neurons ( 50 ). Up-regulation of pannexin-1 expression has been demonstrated to exert an essential influence in multiple brain injury diseases such as epilepsy ( 51 ), sepsis-associated encephalopathy ( 52 ), and subarachnoid hemorrhage ( 53 ). Pannexin-1 channel inhibitor can improve neurological dysfunction and exert neuroprotective effects by means of reducing inflammasomes activation ( 54 ).…”

The cytoplasmic sensor, the AIM2 inflammasome: A precise therapeutic target in vascular and metabolic diseases

“…Following SAH, AIM2 inflammasome-mediated pyroptosis triggered by GSDMD led to early brain injury (EBI) (Yuan et al, 2020). The pannexin-1 channel inhibitor probenecid could reduce early brain injury after SAH by inhibiting neuronal AIM2 inflammasome activation (Zheng et al, 2022).…”