Dexmedetomidine Alleviates LPS-Induced Neuronal Dysfunction by Modulating the AKT/GSK-3β/CRMP-2 Pathway in Hippocampal Neurons

NUDT21 relieves sevoflurane-induced neurological damage in rats by down-regulating LIMK2

Postoperative cognitive dysfunction (POCD) is a common complication of cognitive decline after surgery and anesthesia. Sevoflurane, as a commonly used anesthetic, was found to cause POCD. Nudix Hydrolase 21 (NUDT21), a conserved splicing factor, has been reported to exert important functions in multiple diseases' progression. In this study, the effect of NUDT21 on sevoflurane-induced POCD was elucidated. Results showed that NUDT21 was down-regulated in the hippocampal tissue of sevoflurane-induced rats. Morris water maze test results revealed that overexpression of NUDT21 improved sevoflurane-induced cognitive impairment. In addition, TUNEL assay results indicated that enhanced NUDT21 alleviated sevoflurane-induced apoptosis of hippocampal neurons. Furthermore, overexpression of NUDT21 suppressed the sevoflurane-induced LIMK2 expression. Taken together, NUDT21 alleviates sevoflurane-induced neurological damage in rats by down-regulating LIMK2, providing a novel target for the prevention of sevoflurane-induced POCD.

Effects of LncRNA GAS5/miR-137 general anesthesia on cognitive function by TCF4 inflammatory bodies in patients undergoing lumbar spinal canal decompression

Lumbar spinal stenosis is a common orthopedic disease in clinical practice at present. Postoperative cognitive dysfunction (POCD) refers to the phenomenon of impaired memory. However, whether long noncoding RNA (LncRNA) GAS5 contributes to the mechanism of cognitive function in undergoing lumbar spinal canal decompression remains unknown. Thus, the present study investigated the precise details of LncRNA GAS5 involvement in Postoperative cognitive dysfunction of patients undergoing lumbar spinal canal decompression. Patients undergoing lumbar spinal canal decompression with cognitive function and Normal healthy volunteers were obtained. C57BL/6 mice were maintained with a 2% concentration of sevoflurane in 100% oxygen at a flow rate of 2 L minute-1 for 4 hours. LncRNA GAS5 gene expression were up-regulated in patients undergoing lumbar spinal canal decompression. In mice model, LncRNA GAS5 gene expression also increased. LncRNA GAS5 promoted neuroinflammation in vitro model. LncRNA GAS5 raised cognitive impairment and increased neuroinflammation in mice model. LncRNA GAS5 suppressed miR-137 in vitro model. MiR-137 reduced neuroinflammation in vitro model. MiR-137 suppressed TCF4 protein expression in vitro model. Transcription factor TCF4 activates the expression of bHLH. Taking together, this experiment provide the first experimental and clinical evidence that LncRNA GAS5/miR-137 promoted anesthesia-induced cognitive function to increase inflammatory bodies in patients undergoing lumbar spinal canal decompression, suggesting it may be a biomarker of POCD and a potential therapeutic target for POCD.

Identification of circRNA-miRNA-mRNA networks to explore the molecular mechanism and immune regulation of postoperative neurocognitive disorder

Postoperative neurocognitive disorder (PND) is a common complication in older patients. However, its pathogenesis has still remained elusive. Recent studies have shown that circular RNA (circRNA) plays an important role in the development of neurodegenerative diseases, such as PND after surgery. CircRNA, as a competitive endogenous RNA (ceRNA), mainly acts as a molecular sponge for miRNA to "adsorb" microRNA (miRNA) and to reduce the inhibitory effects of miRNAs on target mRNA. The sequencing data of circRNA were obtained from the Gene Expression Omnibus (GEO) database. By bioinformatic methods, circAtlas, miRDB, miRTarBase and miRwalk databases were applied to construct circRNA-miRNA-mRNA networks and screen differentially expressed mRNAs. To improve the accuracy of the data, we randomly divided aging mice into control (non-PND group) and PND groups, and used high-throughput sequencing to analyze their brain hippocampal tissue for analysis. Three key genes were cross-detected in the data of both groups, which were Unc13c, Tbx20 and St8sia2 (as hub genes), providing new targets for PND treatment. According to the results of the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, immune cell infiltration analysis, gene set enrichment analysis (GSEA), Connectivity Map (CMap) analysis, quantitative real-time polymerase chain reaction (qRT-PCR), the genes that were not related to the central nervous system were removed, and finally, mmu_circ_0000331/miR-1224-3p/Unc13c and mmu_circ_0000406/miR-24-3p/St8sia2 ceRNA networks were identified. In addition, the CMap method was used to select the top 4 active compounds with the largest negative correlation absolute values, including cimaterol, Rucaparib, FG-7142, and Hydrocortisone.

Dexmedetomidine Mitigates Microglial Activation Associated with Postoperative Cognitive Dysfunction by Modulating the MicroRNA-103a-3p/VAMP1 Axis

Surgery-induced microglial activation is critical in mediating postoperative cognitive dysfunction (POCD) in elderly patients, where the important protective effect of dexmedetomidine has been indicated. However, the mechanisms of action of dexmedetomidine during the neuroinflammatory response that underlies POCD remain largely unknown. We found that lipopolysaccharide (LPS) induced substantial inflammatory responses in primary and BV2 microglial cells. The screening of differentially expressed miRNAs revealed that miR-103a-3p was downregulated in these cell culture models. Overexpression of miR-103a-3p mimics and inhibitors suppressed and enhanced the release of inflammatory factors, respectively. VAMP1 expression was upregulated in LPS-treated primary and BV-2 microglial cells, and it was validated as a downstream target of miR-103-3p. VAMP1-knockdown significantly inhibited the LPS-induced inflammatory response. Dexmedetomidine treatment markedly inhibited LPS-induced inflammation and the expression of VAMP1, and miR-103a-3p expression reversed this inhibition. Moreover, dexmedetomidine mitigated microglial activation and the associated inflammatory response in a rat model of surgical trauma that mimicked POCD. In this model, dexmedetomidine reversed miR-103a-3p and VAMP1 expression; this effect was abolished by miR-103a-3p overexpression. Taken together, the data show that miR-103a-3p/VAMP1 is critical for surgery-induced microglial activation of POCD.