内质网应激介导的自噬通过抑制 CHOP 信号通路减轻脂多糖诱导的髓核细胞焦亡。
Endoplasmic reticulum stress-mediated autophagy alleviates lipopolysaccharide-induced nucleus pulposus cell pyroptosis by inhibiting CHOP signaling in vitro.
机构信息
Department of Spine Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
出版信息
J Biochem Mol Toxicol. 2024 Jan;38(1):e23523. doi: 10.1002/jbt.23523. Epub 2023 Aug 31.
Pyroptosis, a newly discovered pro-inflammatory programmed necrosis of cells, serves as an initiating and promoting event that leads to intervertebral disc (IVD) degeneration (IDD). Endoplasmic reticulum stress (ERS) and autophagy are vital regulatory mechanisms of cellular homeostasis, which is also closely related to IDD. However, the role and relationship of ERS and autophagy in the pyroptosis of nucleus pulposus cell (NPC) are not well understood. In this research, we aimed to elucidate the role and mechanism of ERS-C/EBP homologous protein (CHOP) in lipopolysaccharide (LPS)-induced cell pyroptosis and determine its interaction with autophagy. ERS and autophagy inducers or inhibitors were used or not in the preconditioning of rat NPCs. Cell viability, pyroptosis-related protein expression, caspase-1 activity assay, and enzyme-linked immunosorbent assay were performed to observe rat NPC pyroptosis after the treatment of LPS. Activation of the ERS pathway and autophagy were assessed by quantitative real-time PCR, western blot analyses, and immunofluorescence staining assay to classify the molecular mechanisms. Our results showed that LPS stimulation induced NPC pyroptosis with concomitant activation of the ERS-CHOP pathway and initiated autophagy. Activation of the ERS-CHOP pathway exacerbated rat NPC pyroptosis, whereas autophagy inhibited cell pyroptosis. LPS-induced cell pyroptosis and CHOP upregulation were negatively regulated by autophagy. LPS-induced autophagy was depressed by the ERS inhibitor but aggravated by the ERS inducer. Taken together, our findings suggested that LPS induced NPC pyroptosis by activating ERS-CHOP signaling and ERS mediated LPS-induced autophagy, which in turn alleviated NPC pyroptosis by inhibiting CHOP signaling.
细胞焦亡是一种新近发现的细胞炎症程序性坏死,作为引发和促进椎间盘退变(IDD)的始动事件。内质网应激(ERS)和自噬是细胞内稳态的重要调节机制,与 IDD 也密切相关。然而,ERS 和自噬在髓核细胞(NPC)细胞焦亡中的作用和关系尚不清楚。在本研究中,我们旨在阐明 ERS 关键调节因子 C/EBP 同源蛋白(CHOP)在脂多糖(LPS)诱导的 NPC 细胞焦亡中的作用和机制,并确定其与自噬的相互作用。在大鼠 NPC 预处理中使用或不使用 ERS 和自噬诱导剂或抑制剂。采用 LPS 处理后观察大鼠 NPC 细胞焦亡,检测细胞活力、细胞焦亡相关蛋白表达、半胱氨酸天冬氨酸蛋白酶-1(caspase-1)活性测定和酶联免疫吸附试验。通过实时定量 PCR、Western blot 分析和免疫荧光染色试验评估 ERS 通路和自噬的激活,以分类分子机制。结果表明,LPS 刺激诱导 NPC 细胞焦亡,同时激活 ERS-CHOP 通路并启动自噬。ERS-CHOP 通路的激活加剧了大鼠 NPC 细胞焦亡,而自噬抑制了细胞焦亡。LPS 诱导的细胞焦亡和 CHOP 上调受自噬负调控。ERS 抑制剂抑制 LPS 诱导的细胞自噬,而 ERS 诱导剂则加剧 LPS 诱导的细胞自噬。综上所述,本研究结果表明 LPS 通过激活 ERS-CHOP 信号诱导 NPC 细胞焦亡,ERS 介导 LPS 诱导的自噬进而通过抑制 CHOP 信号减轻 NPC 细胞焦亡。