UiO-66 nanoparticles combat influenza A virus in mice by activating the RIG-I-like receptor signaling pathway

The Influenza A virus (IAV) is a zoonotic pathogen that infects humans and various animal species. Infection with IAV can cause fever, anorexia, and dyspnea and is often accompanied by pneumonia characterized by an excessive release of cytokines (i.e., cytokine storm). Nanodrug delivery systems and nanoparticles are a novel approach to address IAV infections. Herein, UiO-66 nanoparticles (NPs) are synthesized using a high-temperature melting reaction. The in vitro and in vivo optimal concentrations of UiO-66 NPs for antiviral activity are 200 μg mL-1 and 60 mg kg-1, respectively. Transcriptome analysis revealed that UiO-66 NPs can activate the RIG-I-like receptor signaling pathway, thereby enhancing the downstream type I interferon antiviral effect. These NPs suppress inflammation-related pathways, including the FOXO, HIF, and AMPK signaling pathways. The inhibitory effect of UiO-66 NPs on the adsorption and entry of IAV into A549 cells is significant. This study presents novel findings that demonstrate the effective inhibition of IAV adsorption and entry into cells via UiO-66 NPs and highlights their ability to activate the cellular RIG-I-like receptor signaling pathway, thereby exerting an anti-IAV effect in vitro or in mice. These results provide valuable insights into the mechanism of action of UiO-66 NPs against IAV and substantial data for advancing innovative antiviral nanomedicine.

Grass Carp Reovirus Major Outer Capsid Protein VP4 Interacts with RNA Sensor RIG-I to Suppress Interferon Response

Diseases caused by viruses threaten the production industry and food safety of aquaculture which is a great animal protein source. Grass carp reovirus (GCRV) has caused tremendous loss, and the molecular function of viral proteins during infection needs further research, as for most aquatic viruses. In this study, interaction between GCRV major outer capsid protein VP4 and RIG-I, a critical viral RNA sensor, was screened out by GST pull-down, endogenous immunoprecipitation and subsequent LC-MS/MS, and then verified by co-IP and an advanced far-red fluorescence complementation system. VP4 was proved to bind to the CARD and RD domains of RIG-I and promoted K48-linked ubiquitination of RIG-I to degrade RIG-I. VP4 reduced mRNA and promoter activities of key genes of RLR pathway and sequential IFN production. As a consequence, antiviral effectors were suppressed and GCRV replication increased, resulting in intensified cytopathic effect. Furthermore, results of transcriptome sequencing of VP4 stably expressed CIK (C. idella kidney) cells indicated that VP4 activated the MyD88-dependent TLR pathway. Knockdown of VP4 obtained opposite effects. These results collectively revealed that VP4 interacts with RIG-I to restrain interferon response and assist GCRV invasion. This study lays the foundation for anti-dsRNA virus molecular function research in teleost and provides a novel insight into the strategy of immune evasion for aquatic virus.

Bioinformatics identification of key candidate genes and pathways associated with systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by autoantibody production and multi-system involvement, but the etiology is largely unclear. This study aimed to elucidate candidate genes and pathways involved in SLE.

METHODS

Three original datasets GSE72509, GSE20864, and GSE39088 were downloaded from Gene Expression Omnibus (GEO) and the data were further integrated and analyzed. Subsequently, differentially expressed genes (DEGs) between SLE patients and healthy people were identified. And then we performed gene ontology (GO) function and pathway enrichment analyses of common DEGs, and constructed a protein-protein interaction (PPI) network with STRING database. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was carried out to validate the expression levels of candidate genes in blood samples from SLE patients and healthy controls.

RESULTS

In total, 321 common DEGs were identified in SLE patients compared with healthy controls, including 231 upregulated and 90 downregulated genes. GO function analysis revealed that 321 common DEGs were mainly enriched in innate immune response, defense response, cytokine-mediated signaling pathway, response to interferon-alpha, and I-kappaB kinase/NF-kappaB signaling. Additionally, pathway enrichment analysis indicated that DEGs were mainly enriched in several signaling pathways associated with immune system and apoptosis, including RIG-I-like receptor signaling pathway, antigen processing and presentation, and p53 signaling pathway. The expression levels of candidate genes RPL26L1, FBXW11, FOXO1, and SMAD7 were validated by RT-qPCR analysis.

CONCLUSIONS

The four hub genes including RPL26L1, FBXW11, FOXO1, and SMAD7 may play key roles in the pathogenesis and development of SLE. RIG-I-like receptor signaling pathway, antigen processing and presentation pathway, and p53 signaling pathway may be closely implicated in SLE pathogenesis. Collectively, these results may provide valuable novel markers or targets for the diagnosis and treatment of SLE.Key Points• Integrated bioinformatics analysis of three profile datasets based on SLE patients and healthy controls was performed and 321 common DEGs were identified.• The 321 common DEGs were mainly enriched in biological processes related to immune responses and inflammatory responses, including innate immune response, defense response, cytokine-mediated signaling pathway, response to interferon-alpha, I-kappaB kinase/NF-kappaB signaling, whereas the three most significant cellular components were oxidoreductase complex, AIM2 inflammasome complex, and ubiquitin ligase complex.• KEGG pathway enrichment analysis indicated that common DEGs were mainly enriched in several signaling pathways associated with immune system and apoptosis, including RIG-I-like receptor signaling pathway, antigen processing and presentation, and p53 signaling pathway.• Candidate genes RPL26L1, FBXW11, FOXO1, and SMAD7 may be closely involved in the pathogenesis and development of SLE and may provide valuable novel markers or targets for the diagnosis and treatment of SLE.

lncRNA AFAP1-AS1 Promotes Migration and Invasion of Non-Small Cell Lung Cancer via Up-Regulating IRF7 and the RIG-I-Like Receptor Signaling Pathway

BACKGROUND/AIMS

Accumulating evidence has highlighted the importance of long non-coding RNAs (lncRNAs) as competing endogenous RNAs (ceRNAs) in tumor biology. Among others, actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been associated with non-small cell lung cancer (NSCLC). However, it remains unclear how AFAP1-AS1 participates in the development and progression of NSCLC.

METHODS

The peripheral blood samples were collected from patients with NSCLC. White blood cell subsets were classified and levels of interleukin (IL)-10, IL-12 and IFN-γ in serum were measured. We then identified its target gene of AFAP1-AS1 via bioinformatics methods. NSCLC cell line with the highest expression of AFAP1-AS1, i.e. H1975 was selected for in vitro experiments. A series of inhibitor, vector and siRNA were employed to validate the regulatory mechanisms of AFAP1-AS1 in the development and progression of NSCLC. Cell proliferation was detected by MTT assay and EdU staining. Cell migration and invasion, and cell cycle and apoptosis were measured by transwell assay and flow cytometry, respectively.

RESULTS

A high expression of AFAP1-AS1 was identified in NSCLC, alongside with a reduced level of IL-12 and increased levels of IL-10 and interferon (IFN)-γ. Aberrant expressions of AFAP1-AS1 were associated with pathological grade, TNM staging and metastatic potential of NSCLC. AFAP1-AS1 could activate interferon regulatory factor (IRF)7, the retinoid-inducible protein (RIG)-I-like receptor signaling pathway and Bcl-2 in vitro. Over-expression of AFAP1-AS1 promoted NSCLC cell proliferation, invasion and migration while inhibiting cell apoptosis.

CONCLUSION

lncRNA AFAP1-AS1 promotes migration and invasion of non-small cell lung cancer via up-regulating IRF7 and the RIG-I-like receptor signaling pathway.

[Retinal transcriptome profile in mice following dexamethasone treatment for endotoxin-induced uveitis]

OBJECTIVE

To investigate the changes in retinal transcriptome profile of mice with endotoxin-induced uveitis (EIU)following dexamethasone (DEX) treatment and explore the mechanisms underlying the therapeutic effect of DEX.

METHODS

EIU was induced in BALB/c mice by intravitreal injection of 125 ng lipopolysaccharide (LPS), followed by topical applicationof DEX (0.1%) eye drops every 4 h for 24 h. The anterior chamber inflammation was examined with a slit lamp and the clinicalscores were assessed. The morphological changes in the eyes were assessed at 24 h after LPS injection. The retinas wereharvested for analysis of transcriptome profile using the next-generation sequencing (NGS)-based RNA sequencing (RNA-seq), and the expressions of the inflammatory cytokines and the differentially expressed genes (DEGs) were verified using real-timePCR.

RESULTS

DEX alleviated the inflammatory response and reduced the mRNA expressions of IL-6, TNF- a, MCP-1 andICAM-1 at 24 h after LPS injection. A total of 52 DEGs were identified by RNA-seq. Within these DEGs, 37 genes were upregulated and 15 genes were down-regulated in LPS group as compared with DEX+LPS group. No significantly enriched GeneOntology (GO) terms was noted. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed 6up-regulated and 2 down-regulated KEGG pathways. RIG-I-like receptor signaling pathway and several immune- andinflammation-related genes including Ifit1, H2-T24, Mx2 and Eif2ak2 were significantly down regulated by DEX. Verificationwith RT-PCR yielded results consistent with these findings.

CONCLUSIONS

DEX alleviates LPS-induced inflammatory response inthe retina of mice, and such protective effect is probably mediated by RIG-I like receptor signal pathway and the immune-andinflammation-related genes.