MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice
Abstract Background Perioperative neurocognitive disorder (PND) is a long-term postoperative complication in elderly surgical patients. The underlying mechanism of PND is unclear, and no effective therapies are currently available. It is believed that neuroinflammation plays an important role in tri...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2021-09-01
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| Series: | Journal of Neuroinflammation |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s12974-021-02246-4 |
| _version_ | 1818559891173801984 |
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| author | Wenqiang Zuo Jianshuai Zhao Jinming Zhang Zongping Fang Jiao Deng Ze Fan Yaru Guo Jing Han Wugang Hou Hailong Dong Feifei Xu Lize Xiong |
| author_facet | Wenqiang Zuo Jianshuai Zhao Jinming Zhang Zongping Fang Jiao Deng Ze Fan Yaru Guo Jing Han Wugang Hou Hailong Dong Feifei Xu Lize Xiong |
| author_sort | Wenqiang Zuo |
| collection | DOAJ |
| description | Abstract Background Perioperative neurocognitive disorder (PND) is a long-term postoperative complication in elderly surgical patients. The underlying mechanism of PND is unclear, and no effective therapies are currently available. It is believed that neuroinflammation plays an important role in triggering PND. The secreted glycoprotein myeloid differentiation factor 2 (MD2) functions as an activator of the Toll-like receptor 4 (TLR4) inflammatory pathway, and α5GABAA receptors (α5GABAARs) are known to play a key role in regulating inflammation-induced cognitive deficits. Thus, in this study, we aimed to investigate the role of MD2 in PND and determine whether α5GABAARs are involved in the function of MD2. Methods Eighteen-month-old C57BL/6J mice were subjected to laparotomy under isoflurane anesthesia to induce PND. The Barnes maze was used to assess spatial reference learning and memory, and the expression of hippocampal MD2 was assayed by western blotting. MD2 expression was downregulated by bilateral injection of AAV-shMD2 into the hippocampus or tail vein injection of the synthetic MD2 degrading peptide Tat-CIRP-CMA (TCM) to evaluate the effect of MD2. Primary cultured neurons from brain tissue block containing cortices and hippocampus were treated with Tat-CIRP-CMA to investigate whether downregulating MD2 expression affected the expression of α5GABAARs. Electrophysiology was employed to measure tonic currents. For α5GABAARs intervention experiments, L-655,708 and L-838,417 were used to inhibit or activate α5GABAARs, respectively. Results Surgery under inhaled isoflurane anesthesia induced cognitive impairments and elevated the expression of MD2 in the hippocampus. Downregulation of MD2 expression by AAV-shMD2 or Tat-CIRP-CMA improved the spatial reference learning and memory in animals subjected to anesthesia and surgery. Furthermore, Tat-CIRP-CMA treatment decreased the expression of membrane α5GABAARs and tonic currents in CA1 pyramidal neurons in the hippocampus. Inhibition of α5GABAARs by L-655,708 alleviated cognitive impairments after anesthesia and surgery. More importantly, activation of α5GABAARs by L-838,417 abrogated the protective effects of Tat-CIRP-CMA against anesthesia and surgery-induced spatial reference learning and memory deficits. Conclusions MD2 contributes to the occurrence of PND by regulating α5GABAARs in aged mice, and Tat-CIRP-CMA is a promising neuroprotectant against PND. |
| first_indexed | 2024-12-14T00:31:25Z |
| format | Article |
| id | doaj.art-91097ab0b59145d196c091d5c5dd91a4 |
| institution | Directory Open Access Journal |
| issn | 1742-2094 |
| language | English |
| last_indexed | 2024-12-14T00:31:25Z |
| publishDate | 2021-09-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Neuroinflammation |
| spelling | doaj.art-91097ab0b59145d196c091d5c5dd91a42022-12-21T23:24:49ZengBMCJournal of Neuroinflammation1742-20942021-09-0118111510.1186/s12974-021-02246-4MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged miceWenqiang Zuo0Jianshuai Zhao1Jinming Zhang2Zongping Fang3Jiao Deng4Ze Fan5Yaru Guo6Jing Han7Wugang Hou8Hailong Dong9Feifei Xu10Lize Xiong11Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityKey Laboratory of Modern Teaching Technology, Ministry of Education, Shaanxi Normal UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityKey Laboratory of Modern Teaching Technology, Ministry of Education, Shaanxi Normal UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityDepartment of Anesthesiology and Perioperative Medicine, Xijing Hospital, Air Force Medical UniversityAbstract Background Perioperative neurocognitive disorder (PND) is a long-term postoperative complication in elderly surgical patients. The underlying mechanism of PND is unclear, and no effective therapies are currently available. It is believed that neuroinflammation plays an important role in triggering PND. The secreted glycoprotein myeloid differentiation factor 2 (MD2) functions as an activator of the Toll-like receptor 4 (TLR4) inflammatory pathway, and α5GABAA receptors (α5GABAARs) are known to play a key role in regulating inflammation-induced cognitive deficits. Thus, in this study, we aimed to investigate the role of MD2 in PND and determine whether α5GABAARs are involved in the function of MD2. Methods Eighteen-month-old C57BL/6J mice were subjected to laparotomy under isoflurane anesthesia to induce PND. The Barnes maze was used to assess spatial reference learning and memory, and the expression of hippocampal MD2 was assayed by western blotting. MD2 expression was downregulated by bilateral injection of AAV-shMD2 into the hippocampus or tail vein injection of the synthetic MD2 degrading peptide Tat-CIRP-CMA (TCM) to evaluate the effect of MD2. Primary cultured neurons from brain tissue block containing cortices and hippocampus were treated with Tat-CIRP-CMA to investigate whether downregulating MD2 expression affected the expression of α5GABAARs. Electrophysiology was employed to measure tonic currents. For α5GABAARs intervention experiments, L-655,708 and L-838,417 were used to inhibit or activate α5GABAARs, respectively. Results Surgery under inhaled isoflurane anesthesia induced cognitive impairments and elevated the expression of MD2 in the hippocampus. Downregulation of MD2 expression by AAV-shMD2 or Tat-CIRP-CMA improved the spatial reference learning and memory in animals subjected to anesthesia and surgery. Furthermore, Tat-CIRP-CMA treatment decreased the expression of membrane α5GABAARs and tonic currents in CA1 pyramidal neurons in the hippocampus. Inhibition of α5GABAARs by L-655,708 alleviated cognitive impairments after anesthesia and surgery. More importantly, activation of α5GABAARs by L-838,417 abrogated the protective effects of Tat-CIRP-CMA against anesthesia and surgery-induced spatial reference learning and memory deficits. Conclusions MD2 contributes to the occurrence of PND by regulating α5GABAARs in aged mice, and Tat-CIRP-CMA is a promising neuroprotectant against PND.https://doi.org/10.1186/s12974-021-02246-4Perioperative neurocognitive disorderAged miceMD2α5GABAAR |
| spellingShingle | Wenqiang Zuo Jianshuai Zhao Jinming Zhang Zongping Fang Jiao Deng Ze Fan Yaru Guo Jing Han Wugang Hou Hailong Dong Feifei Xu Lize Xiong MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice Journal of Neuroinflammation Perioperative neurocognitive disorder Aged mice MD2 α5GABAAR |
| title | MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice |
| title_full | MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice |
| title_fullStr | MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice |
| title_full_unstemmed | MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice |
| title_short | MD2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5GABAA receptors in aged mice |
| title_sort | md2 contributes to the pathogenesis of perioperative neurocognitive disorder via the regulation of α5gabaa receptors in aged mice |
| topic | Perioperative neurocognitive disorder Aged mice MD2 α5GABAAR |
| url | https://doi.org/10.1186/s12974-021-02246-4 |
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