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MicroRNAs (miRNAs) have been identified as important biomarkers with great significance for diagnosis and treatment of various diseases. However, their unique properties, such as small size, high sequence homology, and low abundance, make quantitative analysis of miRNAs extremely challenging. Herein, we reported a cascade catalytic hairpin assembly (CCHA) for sensitive and selective detection of miRNA with three kinds of hairpin probes (HP1, HP2, and HP3). In the presence of target miRNA, a series of toehold-mediated intermolecular DNA strand displacement and hybridization was activated among HP1, HP2, and HP3 to assembly numbers of DNA nanoobjects. During this period, the fluorescence response was greatly intensified to indicate the presence and expression level of interested target miRNA. We have demonstrated that the proposed method exhibits a high assay sensitivity to detect low concentration target and an excellent sequence specificity to distinguish even a single-nucleotide difference in vitro. Moreover, we also demonstrated that our design enables the intracellular imaging of miRNA in live cancer and normal cells. These results showing the promising potential of our CCHA for powerful biosensing, clinic diagnosis, or prognosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Postoperative cognitive dysfunction induced by anesthetics commonly occurs in elderly patients. This study aimed to evaluate the protective role of trametenolic acid B (TAB) in sevoflurane-induced cognitive impairments, and explore the underlying mechanisms., Methods: Animal and cell experiments were performed in rats, differentiated PC12 and HAPI cells by exposing to 2% sevoflurane for 5 h. Different concentration (20, 40 and 80 µg/mL) of TAB was administrated in rats and cells. The cognitive function of rats was evaluated using the Morris water maze test and fear conditioning test. The cell proliferation and apoptosis were investigated using a CCK-8 assay and the flow cytometry. Pro-inflammatory cytokines in microglia were measured using ELISA kits. A miRNA microarray assay was conducted to screen differentially expressed miRNAs by TAB in both PC12 and HAPI cells. The luciferase reporter assay and western blot assay were used to assess the E2F1/CCNA2 and NF-κB pathways., Results: TAB significantly alleviated sevoflurane-induced cognitive impairments in rats, improved PC12 cell viability, and inhibited the neuroinflammation of HAPI cells. miR-329-3p was downregulated in PC12 cells but upregulated in HAPI cells by TAB treatment, which mediated the effects of TAB on neurotoxicity and neuroinflammation. E2F1 and NF-κB P65 were two targets of miR-329-3p, and the E2F1/CCNA2 and NF-κB pathways were inhibited by miR-329-3p in PC12 and HAPI cells, respectively., Conclusions: All the results provide evidence for the protective role of TAB against sevoflurane-induced cognitive impairments, which was achieved by alleviating neurotoxicity and neuroinflammation through differentially regulating miR-329-3p in neurons and microglia., (© 2022. The Author(s).)