Dexmedetomidine Mitigated NLRP3-Mediated Neuroinflammation via the Ubiquitin-Autophagy Pathway to Improve Perioperative Neurocognitive Disorder in Mice.
Dexmedetomidine Mitigated NLRP3-Mediated Neuroinflammation via the Ubiquitin-Autophagy Pathway to Improve Perioperative Neurocognitive Disorder in Mice.
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右美托咪定通过泛素自噬途径减轻 NLRP3 介导的神经炎症，改善小鼠围手术期神经认知障碍
DOI：
10.3389/fphar.2021.646265
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发表时间：
2021
影响因子：
5.6
通讯作者：
Hua F
中科院分区：
文献类型：
--
作者：
Zhang L;Xiao F;Zhang J;Wang X;Ying J;Wei G;Chen S;Huang X;Yu W;Liu X;Zheng Q;Xu G;Yu S;Hua F
背景资料：手术和麻醉诱导的围手术期神经认知障碍（PND）与NOD样受体（NLR）家族、Pyrin domain containing 3（NLRP 3）炎性小胶质细胞炎症反应密切相关。抑制神经炎症的发生是改善术后谵妄的重要治疗手段。目前临床上可用于降低术后谵妄发生率的NLRP 3靶向分子较少。右美托咪定（DEX）是一种α2肾上腺素能受体激动剂，具有抗氧化和抗炎活性。目前的研究表明，DEX减少了切割的半胱天冬酶1（CASP 1）的产生，并破坏了NLRP 3-PYD和CARD结构域（PYCARD）-CASP 1复合物组装，从而减少了IL-1β白细胞介素β（IL-1β）的分泌。DEX促进小胶质细胞自噬过程，降低NLRP 3表达。更有趣的是，它促进了NLRP 3的泛素化和降解。因此，这项研究表明，DEX通过激活泛素-自噬途径减少NLRP 3介导的炎症。本研究为DEX治疗PND提供了新的机制。研究方法：C57 BL/6小鼠提前3天预给药DEX，采用腹部探查模型建立围手术期神经认知障碍模型。通过检测NLRP 3-CASP 1/IL-1β蛋白表达和行为学测试，探讨DEX的体内抗炎作用。采用脂多糖（LPS）和三磷酸腺苷（ATP）体外刺激原代小胶质细胞，检测细胞上清中CASP 1和IL-1β的表达，以及细胞质中自噬相关蛋白微管相关蛋白1轻链3 β（MAP 1 LC 3B）和多价螯合体1（SQSTM 1）的表达。同时，采用免疫共沉淀法（Co-IP）检测NLRP 3蛋白的泛素化水平，探讨DEX抗炎作用的新机制。结果如下：DEX预处理可降低手术诱导小鼠海马NLRP 3、CASP 1和IL-1β的蛋白表达，改善小鼠学习记忆能力障碍。同时，DEX还能有效缓解手术引起的海马脑棘密度的降低。DEX可降低CASP 1的切割表达，阻断NLRP 3-PYCARD-CASP 1复合物的组装，并减少IL-1β的分泌。在机械上，它通过自噬-泛素途径加速NLRP 3炎性体的降解，并降低绿色荧光蛋白/红色荧光蛋白MAP 1 LC 3B的比率，这与使用自噬激活剂雷帕霉素（Rapa）时的效果相当。此外，它增加了LPS加ATP刺激小胶质细胞后NLRP 3的泛素化。结论：DEX通过自噬-泛素途径促进NLRP 3炎性小体降解，减轻海马脑炎症，从而改善小鼠的认知障碍。
Background: Surgery and anesthesia-induced perioperative neurocognitive disorder (PND) are closely related to NOD-like receptors (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome microglia inflammatory response. Inhibiting the occurrence of neuroinflammation is an important treatment method to improve postoperative delirium. Fewer NLRP3-targeting molecules are currently available in the clinic to reduce the incidence of postoperative delirium. Dexmedetomidine (DEX), an α2 adrenergic receptor agonist has been shown to have antioxidant and anti-inflammatory activities. The present study showed that DEX reduced the production of cleaved caspase1 (CASP1) and destroyed the NLRP3–PYD And CARD Domain Containing (PYCARD)–CASP1 complex assembly, thereby reducing the secretion of IL-1β interleukin beta (IL-1β). DEX promoted the autophagy process of microglia and reduced NLRP3 expression. More interestingly, it promoted the ubiquitination and degradation of NLRP3. Thus, this study demonstrated that DEX reduced NLRP3-mediated inflammation through the activation of the ubiquitin-autophagy pathway. This study provided a new mechanism for treating PND using DEX. Methods: C57BL/6 mice were pre-administered DEX 3 days in advance, and an abdominal exploration model was used to establish a perioperative neurocognitive disorder model. The anti-inflammatory effect of DEX was explored in vivo by detecting NLRP3-CASP1/IL-1β protein expression and behavioral testing. Primary microglia were stimulated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in vitro, the expression of CASP1 and IL-1β was detected in the supernatant of cells, and the expression of autophagy-related proteins microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) and sequestosome 1 (SQSTM1) was examined in the cytoplasm. Meanwhile, Co-immunoprecipitation (Co-IP) was used to detect NLRP3 protein ubiquitination so as to clarify the new mechanism underlying the anti-inflammatory effect of DEX. Results: Pre-administration of DEX reduced the protein expression of NLRP3, CASP1, and IL-1β in the hippocampus of mice induced by surgery and also improved the impairment of learning and memory ability. At the same time, DEX also effectively relieved the decrease in spine density of the hippocampal brain induced by surgery. DEX decreased the cleaved CASP1 expression, blocked the assembly of NLRP3–PYCARD–CASP1 complex, and also reduced the secretion of mature IL-1β in vitro. Mechanically, it accelerated the degradation of NLRP3 inflammasome via the autophagy–ubiquitin pathway and reduced the green fluorescent protein/red fluorescent protein MAP1LC3B ratio, which was comparable to the effect when using the autophagy activator rapamycin (Rapa). Furthermore, it increased the ubiquitination of NLRP3 after LPS plus ATP stimulated microglia. Conclusion: DEX attenuated the hippocampal brain inflammation by promoting NLRP3 inflammasome degradation via the autophagy–ubiquitin pathway, thus improving cognitive impairment in mice.
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影响因子：
8.8
作者：
Hu J;Vacas S;Feng X;Lutrin D;Uchida Y;Lai IK;Maze M
通讯作者：
Maze M
DOI：
10.3233/jad-170819
发表时间：
2018
期刊：
Journal of Alzheimer's disease : JAD
影响因子：
--
作者：
Forloni G;Balducci C
通讯作者：
Balducci C
影响因子：
16.6
作者：
Choi, Insup;Zhang, Yuanxi;Yue, Zhenyu
通讯作者：
Yue, Zhenyu
影响因子：
20.3
作者：
Ferrucci, L;Corsi, A;Longo, DL
通讯作者：
Longo, DL
DOI：
10.1038/s41569-018-0064-2
发表时间：
2018-09
期刊：
Nature reviews. Cardiology
影响因子：
--
作者：
Ferrucci L;Fabbri E
通讯作者：
Fabbri E