Department of Anesthesiology, South area of the Affiliated Hospital of Chengde Medical College, Chengde, Hebei 067055, China.
Department of Ultrasound, the Affiliated Hospital of Chengde Medical College, Chengde, Hebei 067000, China.
Brain Res Bull. 2024 Oct 15;217:111060. doi: 10.1016/j.brainresbull.2024.111060. Epub 2024 Sep 3.
The molecular biology mechanisms underlying postoperative cognitive dysfunction (POCD) remain unclear, resulting in a lack of specific therapeutic targets and limited clinical treatment options. The NLRP3 pyroptotic pathway, induced by neuroinflammation, is known to promote the development of POCD. Research has shown that lncRNA MEG3 exacerbates cell pyroptosis in various neurological injuries, though the precise mechanism remains to be investigated.
In vitro and in vivo models of POCD were established through treatment with sevoflurane. Gene and protein expression were investigated using qRT-PCR, Western blot analysis, ELISA, and histological staining. Additionally, cell viability and injury were assessed through CCK-8 and LDH assays. Hippocampal-dependent memory and cognitive abilities were evaluated using the Morris Water Maze (MWM) test. Furthermore, the interactions between MEG3 and EZH2/YTHDC1 were validated through RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP).
Our findings reveal that sevoflurane significantly reduced MEG3 and pyroptosis-related proteins in mice. The overexpression of MEG3 protected mice against sevoflurane-induced cognitive dysfunction and reversed sevoflurane-induced pyroptosis in hippocampal neurons. MEG3 induced the downregulation of NLRP3 expression and reduced mRNA stability through its interaction with EZH2/YTHDC1.
In conclusion, our study elucidates that MEG3 inhibits the NLRP3 inflammasome and hippocampal neuron pyroptosis through the recruitment of EZH2/YTHDC1. These findings shed light on the underlying mechanism of MEG3 in the regulation of POCD and suggest that MEG3 could serve as a potential therapeutic target for the treatment of POCD.
术后认知功能障碍(POCD)的分子生物学机制尚不清楚,导致缺乏特定的治疗靶点和有限的临床治疗选择。神经炎症诱导的 NLRP3 焦亡途径被认为促进了 POCD 的发展。研究表明,lncRNA MEG3 加剧了各种神经损伤中的细胞焦亡,但确切的机制仍有待研究。
通过七氟醚处理建立 POCD 的体外和体内模型。使用 qRT-PCR、Western blot 分析、ELISA 和组织学染色研究基因和蛋白质表达。此外,通过 CCK-8 和 LDH 测定评估细胞活力和损伤。通过 Morris 水迷宫(MWM)测试评估海马依赖性记忆和认知能力。此外,通过 RNA 免疫沉淀(RIP)和染色质免疫沉淀(ChIP)验证 MEG3 与 EZH2/YTHDC1 的相互作用。
我们的研究结果表明,七氟醚显著降低了小鼠的 MEG3 和焦亡相关蛋白。MEG3 的过表达可保护小鼠免受七氟醚诱导的认知功能障碍,并逆转七氟醚诱导的海马神经元焦亡。MEG3 通过与 EZH2/YTHDC1 相互作用诱导 NLRP3 表达下调和 mRNA 稳定性降低。
总之,我们的研究表明,MEG3 通过募集 EZH2/YTHDC1 抑制 NLRP3 炎性小体和海马神经元焦亡。这些发现揭示了 MEG3 在调节 POCD 中的潜在机制,并表明 MEG3 可以作为治疗 POCD 的潜在治疗靶点。