Neuroinflammation plays a key role in perioperative neurocognitive disorders (PND). Increased evidences indicate that triggering receptor expressed on myeloid cells 2 (TREM2) can mitigate inflammatory response in the brain, and the aim of this study is to investigate whether TREM2 is involved in surgery-induced cognitive dysfunction in adult mice. We used adult C57BL/6 mice subjected to intramedullary fixation surgery, and found that surgery did not impair the motor ability of mice, but worsened the learning and memory function, and reduced the expression of TREM2. Meanwhile, up-regulated TREM2 expression in the brain of mice, induced by selective TREM2 agonist HSP60, significantly improved the learning and memory, alleviated the neuroinflammation, and decreased the neuronal cell apoptosis in mice. Meanwhile, TREM2-siRNA abolished the increased expression of TREM2 induced by HSP60, and reversed all the HSP60-induced beneficial effects. Therefore, our study indicated that up-regulation of TREM2 alleviated neuroinflammation and improved learning and memory function after surgery in mice.

中文翻译：

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外科手术引起的认知功能障碍可通过触发在髓样细胞上表达的受体2减轻。

神经炎症在围手术期神经认知障碍（PND）中起关键作用。越来越多的证据表明，髓样细胞2（TREM2）上表达的触发受体可以减轻大脑中的炎症反应，本研究的目的是研究TREM2是否参与成年小鼠的手术诱发的认知功能障碍。我们使用了进行了髓内固定手术的成年C57BL / 6小鼠，发现该手术不会损害小鼠的运动能力，但会恶化学习和记忆功能，并降低TREM2的表达。同时，选择性TREM2激动剂HSP60诱导的小鼠大脑中TREM2表达的上调显着改善了小鼠的学习和记忆能力，减轻了神经炎症，并减少了小鼠神经元细胞的凋亡。与此同时，TREM2-siRNA消除了HSP60诱导的TREM2表达的增加，并逆转了所有HSP60诱导的有益作用。因此，我们的研究表明，TREM2的上调减轻了小鼠手术后的神经炎症并改善了学习和记忆功能。