hnRNPAB inhibits Influenza A virus infection by disturbing polymerase activity.

Influenza A virus (IAV) continuously poses a considerable threat to global health through seasonal epidemics and recurring pandemics. IAV RNA-dependent RNA polymerases (FluPol) mediate the transcription of RNA and replication of the viral genome. Searching for targets that inhibit viral polymerase activity helps us develop better antiviral drugs. Here, we identified heterogeneous nuclear ribonucleoprotein A/B (hnRNPAB) as an anti-influenza host factor. hnRNPAB interacts with NP of IAV to inhibit the interaction between PB1 and NP, which is dependent on the 5-amino-acid peptide of the hnRNPAB C-terminal domain (aa 318-322). We further found that the 5-amino-acid peptide blocks the interaction between PB1 and NP to destroy the FluPol activity. In vivo studies demonstrate that hnRNPAB-deficient mice display higher viral burdens, enhanced cytokine production, and increased mortality after influenza infection. These data demonstrate that hnRNPAB perturbs FluPol complex conformation to inhibit IAV infection, providing insights into anti-influenza defense mechanisms.

A novel epitope tag from rabies virus has versatile in vitro applications.

Fusion tag technology is an important tool for rapid separation, purification, and characterization of proteins. Combined with monoclonal antibodies, tag epitope systems can be rapidly adapted to many assay systems. A monoclonal antibody that reacts with the matrix protein of the rabies virus CVS-11 strain was reported. The epitope (termed M) targeted by this antibody contains only six amino acids. We examine whether this specific sequence epitope can be applied as a protein tag. We show ectopic expression of M-tagged proteins has little impact on cell viability or major signaling pathways. The M tag system can be used for western blotting, immunoprecipitation, immunofluorescence staining, and flow cytometry assays. The results indicate the specificity, sensitivity, and versatility of this novel epitope tag system are comparable to the widely used FLAG tag system, providing researchers with an additional tool for molecular analysis. KEY POINTS: • A short peptide (Pro Pro Tyr Asp Asp Asp) can be applied as a new tag. • The new epitope-tagging fusion system has no effect on the main cellular signaling pathway. • The epitope-tagging fusion system can be widely used for western blotting, immunoprecipitation, immunofluorescence, flow cytometry, etc.

Cocktail strategy based on a dual function nanoparticle and immune activator for effective tumor suppressive.

BACKGROUND: Immune checkpoint inhibitor-mediated immunotherapy cannot be carried out on a large scale clinically due to its low universality. In recent years, cyclic guanosine monophosphate synthase/interferon gene stimulating factor (cGAS/STING)-mediated innate immune signaling pathway-mediated immunotherapy has attracted more and more attention. In addition, metabolic inhibitors also show good effects on tumor treatment, but their application is often limited because of their large first pass effect or difficult administration. METHODS: The particle size and potential parameters were measured by DLS. In order to determine the optimal ratio of the two drugs, we calculated the CI value of different nanoparticles through MTT experiment, and simulated their synergistic effect through Gaussian software. Then the morphology and crystal form of the best proportion of drugs were studied by TEM and XRD. The anti-tumor mechanism of composite nanoparticles was confirmed by the determination of metabolic related indexes, Q-PCR and WB. The antitumor effect and immune activation effect were comprehensively evaluated by in vivo and in vitro experiments. RESULTS: Here, we found and synthesized BCP nanoparticles ((BPA + CPI) @ PLGA NPs) which can effectively reduce the metabolism of tumor cells and inhibit cell proliferation. At the same time, the release of mitochondrial DNA (mtDNA) caused by mitochondrial metabolism disorder further activated the cGAS/STING signal pathway in Hepa1-6 cells. We found that the drug-treated Hepa1-6 cells had obvious TBK1 phosphorylation and STING dimerization. Combined with STING agonist, it could effectively promote the activation of CD8 T cells and enhanced the therapeutic effect on liver cancer. CONCLUSION: Our results showed that PLGA nanocarrier can successfully improve the dosage forms of two metabolic inhibitors and show the effect of synergistic therapy. BCP nanoparticles can also activate the innate immunity of tumor cells and significantly enhance tumor inhibition after combined with STING agonists. This study has high reference and transformation value for the combined treatment of immunosuppression and metabolic inhibition.

GOLT1A-KISS1 fusion is associated with metastasis in adenoid cystic carcinomas.

Genetic alterations can drive carcinogenesis. Numerous studies have shown that gene fusion is associated with cancer progression and could provide valuable biomarkers for clinical diagnosis or targets for cancer therapy. Adenoid cystic carcinoma (ACC) is a rare form of adenocarcinoma, characterized by frequent local recurrence and high rates of distant metastasis, ultimately resulting in low survival rates. Owing to the lack of effective therapeutic targets and limited biomarkers for diagnosis, a deeper understanding of the molecular basis of ACC is urgently needed. Here, we show that gene fusion is associated with ACC metastasis. We identified a metastasis suppressor KISS1 fused with a close-by gene, GOLT1A, in highly metastatic ACC cell lines and human specimens. Such fusion blocks KISS1 translation, but not transcription, by introducing 5' upstream open reading frames (uORFs) in the GOLT1A-KISS1 fusion transcript. Deletion of these uORFs rescued KISS1 expression and reduced invasion and migration of metastatic ACC cells. We also detected GOLT1A-KISS1 fusion transcripts in other types of highly metastatic cancer cell lines. Taken together, our results highlight the significance of this novel GOLT1A-KISS1 gene fusion in tumor metastasis and provide a valuable biomarker for clinical diagnosis and future therapeutic targeting of ACC.

Comprehensive investigation of aberrant microRNAs expression in cells culture model of MnCl2-induced neurodegenerative disease.

Manganese (Mn) is required in various human physiological processes. Excessive Mn exposure causes manganism, a progressive neurodegenerative disorder similar to idiopathic Parkinson's disease (IPD). However, the detailed mechanism of Mn-induced neurotoxicity is not yet fully understood. MicroRNAs (miRNAs) play important roles in gene expression regulation, and miRNA expression profile provides additional biological and prognostic information of diseases. In our study, RNA sequencing was performed to profile miRNAs in the SH-SY5Y cells following MnCl2 treatment. Expressions of 73 miRNAs were altered following excessive Mn treatment. Furthermore, has-miR-4306 was identified to target 3'UTR of ATP13A2 (PARK9) directly. Inhibition of has-miR-4306 efficiently restored Mn-induced cytotoxicity. Thus, for the first time, we revealed the miRNA effects of Mn ions to neuron cells, highlighted the involvement of miRNA regulation in neurodegeneration caused by Mn exposure, and provided a potential application of miRNAs in future therapeutic intervention.