Caspase‐1 inhibition prevents neuronal death by targeting the canonical inflammasome pathway of pyroptosis in a murine model of cerebral ischemia

Abstract

Aims The involvement of pyroptosis in ischemic stroke remains to be established. Therefore, we used the specific pyroptosis inhibitor Vx765 as an experimental intervention target in a murine model of stroke. Methods A total of 564 C57BL/6 mice were subjected to photothrombotic procedures and treated via gavage with Vx765 at 1‐hour post‐ischemia. We subsequently assessed the expression of Gasdermin D (GSDMD), inflammasomes, caspase‐1, and interleukin‐1β (IL‐1β) using immunofluorescence (IF) and Western blot (WB) analyses. We also examined ultrastructural changes of cortical neurons with transmission electron microscopy (TEM) and measured infarct volumes dynamically by magnetic resonance imaging (MRI). Moreover, we evaluated the neurologic deficits by modified neurological severity scores, the rotarod test, and Treadscan. Results Elevated expression of GSDMD and GSDMD p30, the pore‐forming subunit, was evident in the peri‐ischemic region on days one and three post‐ischemia. The neuronal plasma, nuclear, and mitochondrial membranes showed ultrastructural damage at day three post‐stroke. Elevated expression of inflammasomes, caspase‐1, and IL‐1β was also present on days one and three post‐injury. There were significant differences between Vx765‐treated and vehicle groups in mean infarct volumes (14.36 vs 21.52 mm3; 12.34 vs 18.56 mm3; 4.13 vs 10.06 mm3; P < .05 at day one, three, and seven post‐surgery, respectively). Mice treated with Vx765 showed better motor recovery as assessed by serial behavior tests and had better neuronal survival, which was attributable to pyroptosis inhibition, as illustrated by downregulated expression of the effector protein GSDMD, inflammasomes, caspase‐1, and IL‐1β. Besides, treatment with Vx765 preserved neuronal membrane structures after the ischemic injury. Conclusions Pyroptosis emerges as an important pathway for neuronal death in an acute ischemic stroke. Vx765, a low molecular weight drug that has proven safe in clinical epilepsy trials, has potential therapeutic value for cerebral ischemia by targeting the canonical inflammasome pathway of pyroptosis.

Blockade of the NLRP3/caspase-1 axis attenuates ketamine-induced hippocampus pyroptosis and cognitive impairment in neonatal rats

“…MCC950 is a highly potent inhibitor that specifically targets and inhibits the NLRP3 inflammasome [ 50 ], while VX765 inhibits caspase-1 activation, as well as reduces IL-1β and IL-18 secretion [ 51 ]. Both MCC950 and VX765 have been shown to have neuroprotective properties in multiple neurological disorders [ 52 – 55 ]. In this study, we discovered that MCC950 and VX765 had no obvious effects on the anesthetic and analgesic properties of ketamine (Additional file 1 : Fig.…”

Relevant mediators involved in and therapies targeting the inflammatory response induced by activation of the NLRP3 inflammasome in ischemic stroke

“…A151, an inhibitor of cyclic GMP-AMP (cGAMP) synthase (cGAS), markedly reduces the expression of calcitonin gene–related peptides (CGRPs) and decreases the activity of absent in melanoma 2 (AIM2) and the expression of pyroptosis-associated proteins, including GSDMD, caspase-1, IL-1β, and IL-18 [ 136 ]. Because pyroptosis is an important neuronal death process, the specific pyrophosphate inhibitor Vx765, which targets the typical inflammasome, has potential therapeutic value for ischemic stroke [ 137 ]. These findings show that targeted pyroptosis can improve neurological function in animal models of ischemic stroke.…”

Immune Responses in the Glaucomatous Retina: Regulation and Dynamics

“…Since the discovery of GsdmD-NT pores as major conduits of the secretion of the mature IL-1β and IL-18 cytokines [125,126], their pivotal role has been recognized in spreading danger signaling, neuroinflammation, and neurotoxicity in a number of CNS pathologies. Gasdermins have been implicated in vascular damage in hyperglycemia-induced diabetic retinopathy [127][128][129][130] and in neuronal loss in animal models of ischemic stroke, Alzheimer's, age-related macular degeneration [131][132][133], and glaucoma [44,134]. Cleaved GsdmD-NT oligomerizes to form megapores that permeate membranes [135] to the mature IL-1β and IL-18 cytokines [125,126] and other soluble proteins, such as proinflammatory alarmin/HMGB1 [136].…”