Gasdermin D serves as a key executioner of pyroptosis in experimental cerebral ischemia and reperfusion model both in vivo and in vitro

Abstract

Even though ischemic stroke is among the leading causes of death worldwide, the pathogenic mechanisms underlying ischemia reperfusion (I/R) brain injury remain unclear. Gasdermin D (GSDMD), as an important factor of pyroptotic death execution downstream of caspase‐11 (noncanonical inflammasome) and caspase‐1 (canonical inflammasome), may be implicated in I/R injury. The current study aimed to investigate the role and possible underlying mechanisms of GSDMD in pyroptosis during I/R injury. Results indicated that the nucleotide‐binding oligomerization domain‐like receptors (NLR family) pyrin domain containing 3 (NLRP3) inflammasomes were assembled and activated after middle cerebral artery occlusion/reperfusion (MCAO/R), leading to increased levels of IL‐1β and IL‐18. Additionally, GSDMD levels were elevated, and its N‐terminal fragment (GSDMD‐N) was cleaved to induce pyroptosis after MCAO/R, which was partly dependent on caspase‐1 activation and its Asp280 amino acid site. Furthermore, it was found that GSDMD‐N could bind to membrane lipids and exhibit membrane‐disrupting cytotoxicity, depending on its Glu15 and Leu156 amino acid sites. Nevertheless, the C‐terminal fragment of gasdermin (GSDMD‐C) exhibited an auto‐inhibitory effect on GSDMD‐N‐induced pyroptosis via binding to GSDMD in the cytoplasm. Taken together, this information suggests that GSDMD may participate in caspase‐1‐mediated pyroptosis during I/R injury both in vivo and in vitro, which could be a potential therapeutic target to reduce brain I/R injury.

Microglial and neuronal cell pyroptosis induced by oxygen-glucose deprivation/reoxygenation aggravates cell injury via activation of the caspase-1/GSDMD signaling pathway

“…A number of studies have identified that the activation of the Gasdermin family proteins is the biological marker for pyroptosis [26][27][28][29]. Few studies have observed that GSDMD was activated in primary cultured cortical neurons or microglia or BV2 cells undergoing OGD or OGD/R [21][22][23], but the time point of GSDMD activation in these studies is different from that in our study, which may be due to the difference in cell type or culture condition. Our study observed the activation of GSDMD in BV2 and HT22 cells after OGD/R.…”

“…Although some studies have suggested that activation of GSDMD and pyroptosis in microglia and neurons in simulated ischemic conditions in vitro [21][22][23], however, it is still unclear whether there is interplay between microglial and neuronal pyroptosis after I/R, which results in inflammatory propagation. Moreover, there isn't any report about activation of GSDME following cerebral I/R.…”

Inhibition of AIM2 inflammasome activation alleviates GSDMD-induced pyroptosis in early brain injury after subarachnoid haemorrhage

“…GSDMD contains~480 amino acids in two domains, and the N-terminal gasdermin domain (GSDMD-N) and the C-terminal gasdermin domain (GSDMD-C) are linked by a long loop. Mounting evidence has demonstrated that GSDMD plays a key role in CNS injury 22,23 . In our study, we also observed that GSDMD was upregulated after SAH.…”

Melatonin exerts neuroprotective effects by inhibiting neuronal pyroptosis and autophagy in STZ‐induced diabetic mice

“…Inhibition of caspase-1 protects against neuronal death induced by brain ischemic injury, trophic factor withdrawal or Aβ treatment. 14,15 Moreover, inhibiting pyroptosis could alleviate diabetic cardiomyopathy, diabetic nephropathy, and diabetic retinopathy. 16 However, whether pyroptosis is involved in diabetes-induced brain injury has not yet been elucidated.…”