Neuroprotection and Mechanism of Gas-miR36-5p from Gastrodia elata in an Alzheimer's Disease Model by Regulating Glycogen Synthase Kinase-3ß.

Alzheimer's disease (AD) is currently the most common neurodegenerative disease. Glycogen synthase kinase 3ß (GSK-3ß) is a pivotal factor in AD pathogenesis. Recent research has demonstrated that plant miRNAs exert cross-kingdom regulation on the target genes in animals. Gastrodia elata (G. elata) is a valuable traditional Chinese medicine that has significant pharmacological activity against diseases of the central nervous system (CNS). Our previous studies have indicated that G. elata-specific miRNA plays a cross-kingdom regulatory role for the NF-κB signaling pathway in mice. In this study, further bioinformatics analysis suggested that Gas-miR36-5p targets GSK-3ß. Through western blot, RT-qPCR, and assessments of T-AOC, SOD, and MDA levels, Gas-miR36-5p demonstrated its neuroprotective effects in an AD cell model. Furthermore, Gas-miR36-5p was detected in the murine brain tissues. The results of the Morris water maze test and western blot analysis provided positive evidence for reversing the learning deficits and hyperphosphorylation of Tau in AD mice, elucidating significant neuroprotective effects in an AD model following G. elata RNA administration. Our research emphasizes Gas-miR36-5p as a novel G. elata-specific miRNA with neuroprotective properties in Alzheimer's disease by targeting GSK-3ß. Consequently, our findings provide valuable insights into the cross-kingdom regulatory mechanisms underlying G. elata-specific miRNA, presenting a novel perspective for the treatment of Alzheimer's disease.

Daphnetin inhibits spinal glial activation via Nrf2/HO-1/NF-κB signaling pathway and attenuates CFA-induced inflammatory pain.

Daphnetin (7, 8-dihydroxycoumarin, DAPH), a coumarin derivative isolated from Daphne odora var., recently draws much more attention as a promising drug candidate to treat neuroinflammatory diseases due to its protective effects against neuroinflammation. However, itscontribution to chronic inflammatory pain is largely unknown. In the current work, we investigated the effects of DAPH in a murine model of inflammatory pain induced by complete Freund's adjuvant (CFA) and its possible underlying mechanisms. Our results showed that DAPH treatment significantly attenuated mechanical allodynia provoked by CFA. A profound inhibition of spinal glial activation, followed by attenuated expression levels of spinal pro-inflammatory cytokines, was observed in DAPH-treated inflammatory pain mice. Further study demonstrated that DAPH mediated negative regulation of spinal NF-κB pathway, as well as its preferential activation of Nrf2/HO-1 signaling pathway in inflammatory pain mice. This study, for the first time, indicated that DAPH might preventthe development of mechanical allodynia in mice with inflammatory pain. And more importantly, these data provide evidence for the potential application of DAPH in the treatment of chronic inflammatory pain.

Identification and Investigation of miRNAs From Gastrodia elata Blume and Their Potential Function.

Gastrodia elata Blume (G. elata) is a valuable traditional Chinese medicine with neuroprotection, anti-inflammatory, and immune regulatory functions. MicroRNAs (miRNA) is a kind of endogenous noncoding small RNAs that plays distinctly important roles for gene regulation of organisms. So far, the research on G. elata is mainly focused on the pharmacological functions of the natural chemical ingredients, and the function of G. elata miRNA remains unknown. In this study, 5,718 known miRNAs and 38 novel miRNAs were identified by high-throughput sequencing from G. elata. Based on GO and KEGG analysis, we found that the human genes possibly regulated by G. elata miRNAs were related to the cell cycle, immune regulation, intercellular communication, etc. Furthermore, two novel miRNAs as Gas-miR01 and Gas-miR02 have stable and high expression in the medicinal tissues of G. elata. Further bioinformatics prediction showed that both Gas-miR01 and Gas-miR02 could target Homo sapiens A20 gene, furthermore, the dual-luciferase reporter gene assay and Western Blotting verified the interaction of Gas-miR01 or Gas-miR02 with A20. These evidences suggested that G. elata-unique miRNAs might be involved in certain physiological processes. The animal experiment showed that Gas-miR01 and Gas-miR02 could be detected in some tissues of mice by intragastric administration; meanwhile, the A20 expression in some tissues of mice was downregulated. These results supported for the functional study of G. elata miRNAs.