A novel peroxisome-related gene signature predicts clinical prognosis and is associated with immune microenvironment in low-grade glioma.

Low-grade glioma (LGG), a common primary tumor, mainly originates from astrocytes and oligodendrocytes. Increasing evidence has shown that peroxisomes function in the regulation of tumorigenesis and development of cancer. However, the prognostic value of peroxisome-related genes (PRGs) in LGG has not been reported. Therefore, it is necessary to construct a prognostic risk model for LGG patients based on the expression profiles of peroxisome-related genes. Our study mainly concentrated on developing a peroxisome-related gene signature for overall survival (OS) prediction in LGG patients. First, according to these peroxisome-related genes, all LGG patients from The Cancer Genome Atlas (TCGA) database could be divided into two subtypes. Univariate Cox regression analysis was used to find prognostic peroxisome-related genes in TCGA_LGG dataset, and least absolute shrinkage and selection operator Cox regression analysis was employed to establish a 14-gene signature. The risk score based on the signature was positively associated with unfavorable prognosis. Then, multivariate Cox regression incorporating additional clinical characteristics showed that the 14-gene signature was an independent predictor of LGG. Time-dependent ROC curves revealed good performance of this prognostic signature in LGG patients. The performance about predicting OS of LGG was validated using the GSE107850 dataset derived from the Gene Expression Omnibus (GEO) database. Furethermore, we constructed a nomogram model based on the gene signature and age, which showed a better prognostic power. Gene ontology (GO) and Kyoto Encylopedia of Genes and Genomes (KEGG) analyses showed that neuroactive ligand-receptor interaction and phagosome were enriched and that the immune status was decreased in the high-risk group. Finally, cell counting kit-8 (CCK8) were used to detect cell proliferation of U251 and A172 cells. Inhibition of ATAD1 (ATPase family AAA domain-containing 1) and ACBD5 (Acyl-CoA binding-domain-containing-5) expression led to significant inhibition of U251 and A172 cell proliferation. Flow cytometry detection showed that ATAD1 and ACBD5 could induce apoptosis of U251 and A172 cells. Therefore, through bioinformatics methods and cell experiments, our study developed a new peroxisome-related gene signature that migh t help improve personalized OS prediction in LGG patients.

Transcriptome profiling and ceRNA network of small extracellular vesicles from resting and degranulated mast cells.

Aim: This study aimed to investigate the transcriptomic characteristics and interactions between competitive endogenous RNAs (ceRNAs) within small extracellular vesicles (sEVs) derived from mast cells (MCs). Methods: Transcriptome sequencing analyzed lncRNA, circRNA and mRNA expression in resting and degranulated MC-derived sEVs. Constructed ceRNA regulatory network through correlation analysis and target gene prediction. Results: Differentially expressed 1673 mRNAs, 173 lncRNAs and 531 circRNAs were observed between resting and degranulated MCs-derived sEVs. Enrichment analysis revealed involvement of neurodegeneration, infection and tumor pathways. CeRNA networks included interactions between lncRNA-miRNA, circRNA-miRNA and miRNA-mRNA, targeting genes in the hippo and wnt signaling pathways linked to tumor immune regulation. Conclusion: This study provides valuable insights into MC-sEV molecular mechanisms, offering significant data resources for further investigations.

Mast cells (MCs) are important for various health conditions, including allergies, infections, tumors and brain disorders. MCs release tiny structures called small extracellular vesicles (sEVs) that carry different molecules, such as genetic material, to communicate with other cells in the body's immune system. However, we still do not know much about how these sEVs work. In this study, we examined the sEVs from MCs and found specific genetic molecules that change when MCs become activated. We discovered that these molecules are involved in important processes related to diseases like neurodegeneration and infection. We also identified networks of molecules that interact with each other, influencing immune regulation of tumor. By studying this, we gain new knowledge about how MCs use sEVs to communicate with other cells in our body during immune responses.

Novel reactivation and degranulation of mast cells.

Mast cells (MCs) degranulation is a key process during the allergic inflammatory response. MCs release their preformed and new synthesized granules after activation. We found that granules were released partially and selectively after the activation of bone marrow-derived mouse mast cells (BMMCs). Next, we investigated the response of degranulated MCs to a new challenge. BMMCs were activated by antibody/antigen (IgE/Ag) or compound 48/80 (C48/80). The degranulated BMMCs were then reactivated by either IgE/Ag or C48/80 without time intervals. Flow cytometry was used to detect the expression of CD117, FcεRI, and intracellular granules of BMMCs, and BMMCs degranulation was detected using the ß-hexosaminidase release assay. The morphology of BMMCs was observed by staining with toluidine blue. Degranulated BMMCs activated by IgE/Ag failed to respond to the same IgE/Ag challenge and released ß-hexosaminidase independent of unoccupied FcεRI, but responded to C48/80. Degranulated BMMCs activated by C48/80 responded to either IgE/Ag or C48/80. These results indicated that degranulated BMMCs could be reactivated and released granule mediators again, this revealed the unique mediator releasing mechanism of degranulated MCs and their potential function in maintaining inflammation or causing hypersensitivity.

Modulatory effects of bufalin, an active ingredient from toad venom on voltage-gated sodium channels.

Chan-su (toad venom) has been used as an analgesic agent in China from ancient to modern times. Bufalin, a non-peptide toxin extracted from toad venom, is considered as one of the analgesic components. The molecular mechanism underlying the anti-nociceptive effects of bufalin remains unclear so far. In this study, we investigated the pharmacological effects of bufalin on pain-related ion channels as well as animal models through patch clamping, calcium imaging and animal behavior observation. Using the whole-cell recording, bufalin caused remarkable suppressive effect on the peak currents of Nav channels (voltage gated sodium channels, VGSCs) of dorsal root ganglion neuroblastomas (ND7-23 cell) in a dose-dependent manner. Bufalin facilitated the voltage-dependent activation and induced a negative shift on the fast inactivation of VGSCs. The recovery kinetics of VGSCs were significantly slowed and the recovery proportion were reduced after administering bufalin. However, bufalin prompted no significant effect not only on Kv4.2, Kv4.3 and BK channels heterologously expressed in HEK293T cells, but also on the capsaicin and allyl isothiocyanate induced Ca2+ influx. What's more, bufalin could observably relieve formalin-induced spontaneous flinching and licking response as well as carrageenan-induced thermal and mechanical hyperalgesia in dose-dependent manner in agreement with the results of in vitro experiments. The present results imply that the remarkable anti-nociceptive effects produced by bufalin are probably ascribed to its specific regulation on Nav channels. Bufalin inhibits the Nav channels in a dose-dependent manner, which will provide references for the optimal dose selection of analgesia drugs.

Alpha-synuclein contributes to malignant progression of human meningioma via the Akt/mTOR pathway.

BACKGROUND: The aim of this study is to explore the expression of alpha-synuclein (α-synuclein) in benign, atypical, and anaplastic meningiomas and determine its role in the malignant progression of meningiomas. METHODS: Expression of α-synuclein was measured in 44 meningioma samples by real-time PCR analysis. The effects of overexpression or knockdown of α-synuclein on meningioma cell growth, invasiveness, and tumorigenicity were determined. RESULTS: Atypical and anaplastic meningiomas displayed significantly greater levels of α-synuclein mRNA, relative to benign tumors. Depletion of α-synuclein decreased cell proliferation and colony formation and promoted apoptosis in IOMM-Lee meningioma cells, whereas overexpression of α-synuclein facilitated cell proliferation and colony formation in CH-157MN meningioma cells. Silencing of α-synuclein attenuated IOMM-Lee cell migration and invasion. In contrast, ectopic expression of α-synuclein increased the invasiveness of CH-157MN cells. In vivo studies further demonstrated that downregulation of α-synuclein significantly retarded meningioma growth in nude mice. At the molecular level, the phosphorylation levels of Akt, mTOR, p70S6K and 4EBP were significantly decreased in α-synuclein-depleted IOMM-Lee cells. CONCLUSIONS: In conclusion, α-synuclein upregulation contributes to aggressive phenotypes of meningiomas via the Akt/mTOR pathway and thus represents a potential therapeutic target for malignant meningiomas.