Exosomal CircMFN2 Enhances the Progression of Pituitary Adenoma via the MiR-146a-3p/TRAF6/NF-κB Pathway.

BACKGROUND: Pituitary adenoma (PA) is a common intracranial endocrine tumor, but no precise target has been found for effective prediction and treatment of PA. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT‒PCR) analysis showed that circMFN2 could affect the expression of miR-146a-3p in PA samples. Moreover, we used Western blotting to evaluate the expression levels of TRAF6 and NF-κB markers. The EdU assay, scratch wound healing assay, and Matrigel invasion assay were performed to assess the potential function of this pathway in PA cells. Based on the bioinformatic analysis including KEGG, gene ontology (GO) analysis, and microarray analysis, we evaluated the efficacy of circMFN2 as a potential biomarker for diagnosing PA, and we aimed to determine the mechanism of action in PA cells. RESULTS: Our findings indicate that there is a significant increase in the expression of circMFN2 in tissues, serum, and exosomes in the invasive group compared with the noninvasive and normal groups. Furthermore, this difference was statistically significant both preoperatively and postoperatively. To clarify its function, we downregulated this gene, and the experimental results suggested that the motility and proliferative capacity were reduced in vitro. In addition, rescue assays showed that miR-146a-3p could successfully reverse the inhibitory effect of circMFN2 knockdown on motility and proliferation in PA cells. Moreover, downregulation of circMFN2 and miR-146a-3p significantly changed the expression of TRAF6 and NF-κB. CONCLUSION: This study identified that circMFN2 regulates miR-146a-3p to promote adenoma development partially via the TRAF6/NF-κB pathway and may be a potential therapeutic target for PA.

Neuroprotective effect of chitosan oligosaccharide on alcohol-induced hippocampal injury using proteomic analysis.

Alcoholism is a serious public health problem, and the abuse of drinking seriously damages the health of people. Chitosan oligosaccharides (COSs) are small-molecule oligosaccharides with amino groups that have many unique properties. The neuroprotective effect of COS on alcohol-induced hippocampal injury in Sprague-Dawley (SD) rats was investigated. The discrimination ratio of the COS group in the Y-maze experiment was 59.3% higher than that of the ETOH group. Meanwhile, the discrimination index was less than 0 in the ETOH group but greater than 0 in the COS group during the object recognition test. The cells in the COS group were more tightly arranged than those in the ETOH group. Proteomics was used to identify differentially expressed proteins in the hippocampus. There were 27 differentially expressed proteins in the COS and ETOH group for further bioinformatic analysis. There are three enriched pathway categories, namely, primary immunodeficiency, hedgehog signaling, and sulfur relay system. Next, sonic hedgehog signaling pathway-related proteins were verified through western blotting. The protein expression level of ß-arrestin-2 in the COS group was 2.85 times higher than that in the ETOH group. This work may contribute to understanding the underlying mechanism of the neuroprotective effect of COS against alcohol-induced hippocampal injury in SD rats.

Chitosan oligosaccharides exert neuroprotective effects via modulating the PI3K/Akt/Bcl-2 pathway in a Parkinsonian model.

Parkinson's disease (PD), the second most common neurodegenerative disease, is a threat to patients due to the inability to prevent or decelerate disease progression. Currently, most clinical drugs for the treatment of PD are synthetic drugs that always present undesirable adverse or toxic effects. Chitosan oligosaccharide (COS) is a natural oligosaccharide that has been considered relatively safe and studied in the therapeutic effects on different types of neuronal disorders. In this study, we separated four COS monomers (COSs) including chitobiose (COS2), chitotriose (COS3), chitotetraose (COS4) and chitopentaose (COS5) to explore their structure-activity relationship in PD mice induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Techniques including TLC, HPLC, MS, and NMR were applied to investigate the purity and structure of the COSs. After the oral administration of COSs, behavior indexes, pathological indexes, cytokines, and expression of proteins in the nigrostriatal pathway of the mice were analyzed. The results showed that the four COSs were fully deacetylated and the purity was >90%. Additionally, the neurobehavioral deficits of the PD mice were improved by treatment with COSs. The results further proved that COSs could protect the TH-labelled dopaminergic neurons via reducing the overexpression of α-synuclein, alleviating neuroinflammation, and activating the PI3K/Akt/Bcl-2 pathway to reduce apoptosis. COS3 exhibited a better effect on protecting dopaminergic neurons; however, COS2 provided a better effect on reducing the overexpression of α-synuclein. To conclude, the neuroprotective activity makes COSs a viable candidate as an ingredient for healthcare products.