GSDMD 敲低通过细胞焦亡和细胞凋亡的串扰加重海马区损伤和红藻氨酸诱导的颞叶癫痫易感性。

GSDMD knockdown exacerbates hippocampal damage and seizure susceptibility by crosstalk between pyroptosis and apoptosis in kainic acid-induced temporal lobe epilepsy.

机构信息

Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Anshan Road NO.154, Tianjin 300052, China; Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1Youyi Road, Chongqing 400016, China.

Department of Neurology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, 32# W. Sec 2, 1st Ring Rd, Chengdu, Sichuan 610072, China.

出版信息

Biochim Biophys Acta Mol Basis Dis. 2023 Jun;1869(5):166687. doi: 10.1016/j.bbadis.2023.166687. Epub 2023 Mar 14.

DOI:10.1016/j.bbadis.2023.166687

PMID:36921736

Abstract

BACKGROUND

Neuronal loss is a vital pathological feature of temporal lobe epilepsy (TLE). However, the exact mechanism of neuronal loss in TLE is not fully understood. Pyroptosis, a novel form of programmed cell death (PCD), has been considered a contributor to the pathogenesis of TLE. However, recent studies have implicated extensive molecular crosstalk among pyroptosis, apoptosis, and necroptosis in various diseases, and they can be transformed to each other according to different contexts. This study aimed to investigate whether gasdermin D (GSDMD)-mediated pyroptosis is involved in the pathogenesis of TLE and whether crosstalk exists in the process of the modulation of pyroptosis.

METHODS

The TLE model was established by intra-amygdala injection of kainic acid. The Racine score and local field potential (LFP) recordings were used to assess seizure severity. Western blotting and immunofluorescence were applied to detect the levels and cellular localization of GSDMD. The neuronal loss and type of neuronal death in the bilateral hippocampus were assessed by Nissl staining and flow cytometry analysis. The underlying crosstalk among pyroptosis, apoptosis, and necroptosis was explored by western blot and verified by VX765.

RESULTS

GSDMD was significantly upregulated and mainly expressed within the neurons of the hippocampus in the TLE model. Inhibition of pyroptosis by GSDMD knockdown triggered caspase-3-mediated apoptosis, leading to excess neuronal loss and deterioration of epileptic behaviors. Blocking caspase-1 markedly inhibited caspase-3-mediated apoptosis and improved epileptic behaviors under GSDMD knockdown.

CONCLUSIONS

Our results demonstrate that GSDMD-mediated pyroptosis is involved in the pathogenesis of TLE. However, inhibition of GSDMD triggers caspase-1-mediated crosstalk between pyroptosis and apoptosis, which exacerbates neuronal loss and seizure susceptibility. Therefore, the complex crosstalk among different forms of PCD should be considered when a potential molecular target in the single PCD pathway is modulated. On the other hand, along with further studies of molecular crosstalk among the PCD pathways, taking advantage of crosstalk to attenuate neuronal loss may provide new insight for the clinical therapy of TLE.

摘要

背景

神经元丢失是颞叶癫痫（TLE）的重要病理特征。然而，TLE 中神经元丢失的确切机制尚不完全清楚。细胞焦亡，一种新的程序性细胞死亡（PCD）形式，被认为是 TLE 发病机制的一个贡献者。然而，最近的研究表明，细胞焦亡、细胞凋亡和坏死性凋亡之间存在广泛的分子串扰，并且它们可以根据不同的情况相互转化。本研究旨在探讨gasdermin D（GSDMD）介导的细胞焦亡是否参与 TLE 的发病机制，以及在细胞焦亡的调节过程中是否存在串扰。

方法

通过内侧杏仁核注射海人酸建立 TLE 模型。Racine 评分和局部场电位（LFP）记录用于评估癫痫发作严重程度。Western blot 和免疫荧光用于检测 GSDMD 的水平和细胞定位。尼氏染色和流式细胞术分析评估双侧海马神经元丢失和神经元死亡类型。通过 Western blot 探讨细胞焦亡、细胞凋亡和坏死性凋亡之间的潜在串扰，并通过 VX765 验证。

结果

在 TLE 模型中，GSDMD 显著上调，主要表达于海马神经元内。通过 GSDMD 敲低抑制细胞焦亡，引发 caspase-3 介导的细胞凋亡，导致过多的神经元丢失和癫痫行为恶化。阻断 caspase-1 明显抑制 GSDMD 敲低后的 caspase-3 介导的细胞凋亡，并改善癫痫行为。

结论

我们的结果表明，GSDMD 介导的细胞焦亡参与 TLE 的发病机制。然而，抑制 GSDMD 触发 caspase-1 介导的细胞焦亡与细胞凋亡之间的串扰，加剧神经元丢失和癫痫易感性。因此，在调节单一 PCD 途径中的潜在分子靶点时，应考虑不同 PCD 形式之间的复杂串扰。另一方面，随着对 PCD 途径之间分子串扰的进一步研究，利用串扰减轻神经元丢失可能为 TLE 的临床治疗提供新的思路。