Uncoupling of macrophage inflammation from self-renewal modulates host recovery from respiratory viral infection.

Tissue macrophages self-renew during homeostasis and produce inflammatory mediators upon microbial infection. We examined the relationship between proliferative and inflammatory properties of tissue macrophages by defining the impact of the Wnt/ß-catenin pathway, a central regulator of self-renewal, in alveolar macrophages (AMs). Activation of ß-catenin by Wnt ligand inhibited AM proliferation and stemness, but promoted inflammatory activity. In a murine influenza viral pneumonia model, ß-catenin-mediated AM inflammatory activity promoted acute host morbidity; in contrast, AM proliferation enabled repopulation of reparative AMs and tissue recovery following viral clearance. Mechanistically, Wnt treatment promoted ß-catenin-HIF-1α interaction and glycolysis-dependent inflammation while suppressing mitochondrial metabolism and thereby, AM proliferation. Differential HIF-1α activities distinguished proliferative and inflammatory AMs in vivo. This ß-catenin-HIF-1α axis was conserved in human AMs and enhanced HIF-1α expression associated with macrophage inflammation in COVID-19 patients. Thus, inflammatory and reparative activities of lung macrophages are regulated by ß-catenin-HIF-1α signaling, with implications for the treatment of severe respiratory diseases.

Versatile Fluorescence Lifetime-Based Copper Probe to Quantify Mitochondrial Membrane Potential and Reveal Its Interaction with Protein Aggregation.

Mitochondria play a crucial role in maintaining cellular homeostasis, and the depolarization of mitochondrial membrane potential (MMP) is an important signal of apoptosis. Additionally, protein misfolding and aggregation are closely related to diseases including neurodegenerative diseases, diabetes, and cancers. However, the interaction between MMP changes and disease-related protein aggregation was rarely studied. Herein, we report a novel "turn-on" fluorescent probe MitoRhB that specifically targets to mitochondria for Cu2+ detection in situ. The fluorescence lifetime (τ) of MitoRhB exhibits a positive correlation with MMP changes, allowing us to quantitatively determine the relative MMP during SOD1 (A4 V) protein aggregation. Finally, we found that (1) the increasing concentrations of copper will accelerate the depolarization of mitochondria and reduce MMP; (2) the depolarization of mitochondria can intensify the degree of protein aggregation, suggesting a new routine of copper-induced cell death mediated through abnormal MMP depolarization and protein aggregation.

TFAM-Dependent Mitochondrial Metabolism Is Required for Alveolar Macrophage Maintenance and Homeostasis.

Alveolar macrophages (AMs) are major lung tissue-resident macrophages capable of proliferating and self-renewal in situ. AMs are vital in pulmonary antimicrobial immunity and surfactant clearance. The mechanisms regulating AM compartment formation and maintenance remain to be fully elucidated currently. In this study, we have explored the roles of mitochondrial transcription factor A (TFAM)-mediated mitochondrial fitness and metabolism in regulating AM formation and function. We found that TFAM deficiency in mice resulted in significantly reduced AM numbers and impaired AM maturation in vivo. TFAM deficiency was not required for the generation of AM precursors nor the differentiation of AM precursors into AMs, but was critical for the maintenance of AM compartment. Mechanistically, TFAM deficiency diminished gene programs associated with AM proliferation and self-renewal and promoted the expression of inflammatory genes in AMs. We further showed that TFAM-mediated AM compartment impairment resulted in defective clearance of cellular debris and surfactant in the lung and increased the host susceptibility to severe influenza virus infection. Finally, we found that influenza virus infection in AMs led to impaired TFAM expression and diminished mitochondrial fitness and metabolism. Thus, our data have established the critical function of TFAM-mediated mitochondrial metabolism in AM maintenance and function.

UPLC-QE-Orbitrap-Based Cell Metabolomics and Network Pharmacology to Reveal the Mechanism of N-Benzylhexadecanamide Isolated from Maca (Lepidium meyenii Walp.) against Testicular Dysfunction.

Testicular dysfunction (TDF) is characterized by testosterone deficiency and is caused by oxidative stress injury in Leydig cells. A natural fatty amide named N-benzylhexadecanamide (NBH), derived from cruciferous maca, has been shown to promote testosterone production. Our study aims to reveal the anti-TDF effect of NBH and explore its potential mechanism in vitro. This study examined the effects of H2O2 on cell viability and testosterone levels in mouse Leydig cells (TM3) under oxidative stress. In addition, cell metabolomics analysis based on UPLC-Q-Exactive-MS/MS showed that NBH was mainly involved in arginine biosynthesis, aminoacyl-tRNA biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, the TCA cycle and other metabolic pathways by affecting 23 differential metabolites, including arginine and phenylalanine. Furthermore, we also performed network pharmacological analysis to observe the key protein targets in NBH treatment. The results showed that its role was to up-regulate ALOX5, down-regulate CYP1A2, and play a role in promoting testicular activity by participating in the steroid hormone biosynthesis pathway. In summary, our study not only provides new insights into the biochemical mechanisms of natural compounds in the treatment of TDF, but also provides a research strategy that integrates cell metabolomics and network pharmacology in order to promote the screening of new drugs for the treatment of TDF.

Screening of the Active Compounds against Neural Oxidative Damage from Ginseng Phloem Using UPLC-Q-Exactive-MS/MS Coupled with the Content-Effect Weighted Method.

The neuroprotective properties of ginsenosides have been found to reverse the neurological damage caused by oxidation in many neurodegenerative diseases. However, the distribution of ginsenosides in different tissues of the main root, which was regarded as the primary medicinal portion in clinical practice was different, the specific parts and specific components against neural oxidative damage were not clear. The present study aims to screen and determine the potential compounds in different parts of the main root in ginseng. Comparison of the protective effects in the main root, phloem and xylem of ginseng on hydrogen peroxide-induced cell death of SH-SY5Y neurons was investigated. UPLC-Q-Exactive-MS/MS was used to quickly and comprehensively characterize the chemical compositions of the active parts. Network pharmacology combined with a molecular docking approach was employed to virtually screen for disease-related targets and potential active compounds. By comparing the changes before and after Content-Effect weighting, the compounds with stronger anti-nerve oxidative damage activity were screened out more accurately. Finally, the activity of the selected monomer components was verified. The results suggested that the phloem of ginseng was the most effective part. There were 19 effective compounds and 14 core targets, and enriched signaling pathway and biological functions were predicted. After Content-Effect weighting, compounds Ginsenosides F1, Ginsenosides Rf, Ginsenosides Rg1 and Ginsenosides Rd were screened out as potential active compounds against neural oxidative damage. The activity verification study indicated that all four predicted ginsenosides were effective in protecting SH-SY5Y cells from oxidative injury. The four compounds can be further investigated as potential lead compounds for neurodegenerative diseases. This also provides a combined virtual and practical method for the simple and rapid screening of active ingredients in natural products.

Eukaryotic Translation Elongation Factor 1 Delta Inhibits the Nuclear Import of the Nucleoprotein and PA-PB1 Heterodimer of Influenza A Virus.

The viral ribonucleoprotein (vRNP) of the influenza A virus (IAV) is responsible for the viral RNA transcription and replication in the nucleus, and its functions rely on host factors. Previous studies have indicated that eukaryotic translation elongation factor 1 delta (eEF1D) may associate with RNP subunits, but its roles in IAV replication are unclear. Herein, we showed that eEF1D was an inhibitor of IAV replication because knockout of eEF1D resulted in a significant increase in virus yield. eEF1D interacted with RNP subunits polymerase acidic protein (PA), polymerase basic 1 (PB1), polymerase basic 2 (PB2), and also with nucleoprotein (NP) in an RNA-dependent manner. Further studies revealed that eEF1D impeded the nuclear import of NP and PA-PB1 heterodimer of IAV, thereby suppressing the vRNP assembly, viral polymerase activity, and viral RNA synthesis. Together, our studies demonstrate eEF1D negatively regulating the IAV replication by inhibition of the nuclear import of RNP subunits, which not only uncovers a novel role of eEF1D in IAV replication but also provides new insights into the mechanisms of nuclear import of vRNP proteins.IMPORTANCE Influenza A virus is the major cause of influenza, a respiratory disease in humans and animals. Different from most other RNA viruses, the transcription and replication of IAV occur in the cell nucleus. Therefore, the vRNPs must be imported into the nucleus for viral transcription and replication, which requires participation of host proteins. However, the mechanisms of the IAV-host interactions involved in nuclear import remain poorly understood. Here, we identified eEF1D as a novel inhibitor for the influenza virus life cycle. Importantly, eEF1D impaired the interaction between NP and importin α5 and the interaction between PB1 and RanBP5, which impeded the nuclear import of vRNP. Our studies not only reveal the molecular mechanisms of the nuclear import of IAV vRNP but also provide potential anti-influenza targets for antiviral development.

A practicable method to prepare nitrated proteins with peroxynitrite and low concentration of sodium hydroxide.

Peroxynitrite is an ion acting as a powerful oxidant and nucleophile, which plays a key role in the inflammation and aging process by nitrating tyrosine or tryptophan residues of the proteins. Nitration of a target protein is considered to be a proper method to study the behavioral change of the proteins being nitrated. The commonly used methods for peroxynitrite preparation in vitro usually contain high concentration of sodium hydroxide, which easily induces hydrolysis of target proteins. Accordingly, the method for peroxynitrite preparation was optimized in vitro by changing the sequence of hydrochloric acid and sodium hydroxide added. After different amount of hydrochloric acid added to the system following sodium nitrite, peroxynitrite can be yielded in a concentration up to 60 mM with sodium hydroxide as low as 17 mM. More importantly, biological activity of the target protein was well maintained after protein nitration since low sodium hydroxide was used.

Screening of the Hepatotoxic Components in Fructus Gardeniae and Their Effects on Rat Liver BRL-3A Cells.

Fructus Gardeniae (FG) is a common Chinese medicine and food. However, the toxicity of FG has drawn increasing concern, especially its hepatotoxicity. The purpose of this study was to screen the hepatotoxic components of FG and evaluate their effects on rat liver BRL-3A cells. The chemical composition of FG was determined by HPLC-ESI-MS. CCK-8 assay was used to evaluate the cytotoxicity of ten chemical components from FG, and then the toxic components with significant inhibitory activity were selected for further study. The results showed that geniposide, genipin, genipin-1-gentiobioside, gardenoside, and shanzhiside all suppress cells viability. Apoptosis assays further indicated that geniposide and its metabolite genipin are the main hepatotoxic components of FG. Pretreatment of cells with geniposide or genipin increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The activities of superoxide dismutase (SOD) and glutathione (GSH) were decreased, while the malondialdehyde (MDA) level was increased. The cell contents of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) were also increased. Molecular docking simulations were used to investigate the mechanism of FG-induced hepatotoxicity, revealing that geniposide and genipin bind strongly to the pro-inflammatory factor TNFR1 receptor of the NF-κB and MAPK signaling pathways. The obtained results strongly indicate that the hepatotoxicity of FG is caused by iridoids compounds. Genipin had the most significant hepatotoxic effect. These toxic substances destroy the cell antioxidant defense system, increasing inflammatory injury to the liver cells and leading to apoptosis and even necrosis. Thus, this study lays a foundation for toxicology research into FG and its rational application.

Screening of the Active Component Promoting Leydig Cell Proliferation from Lepidium meyenii Using HPLC-ESI-MS/MS Coupled with Multivariate Statistical Analysis.

Lepidium meyenii is now widely consumed as a functional food and medicinal product, which is known as an enhancer of reproductive health. However, the specific chemical composition and mechanism of action for improving sexual function are unclear. The present study aims at screening and determining the potential compounds, which promote mouse leydig cells (TM3) proliferation. The partial least squares analysis (PLS) was employed to reveal the correlation between common peaks of high performance liquid chromatography (HPLC) fingerprint of L. meyenii and the proliferation activity of TM3. The results suggested that three compounds had good activities on the proliferation of TM3 and promoting testosterone secretion, there were N-benzyl-hexadecanamide, N-benzyl-(9z,12z)-octadecadienamide and N-benzyl-(9z,12z,15z)-octadecatrienamide which might be the potential bioactive markers related to the enhancing sexual ability functions of L. meyenii. The first step in testosterone synthesis is the transport of cholesterol into the mitochondria, and the homeostasis of mitochondrial function is related to cyclophilin D (CypD). In order to expound how bioactive ingredients lead to promoting testosterone secretion, a molecular docking simulation was used for further illustration in the active sites and binding degree of the ligands on CypD. The results indicated there was a positive correlation between the binding energy absolute value and testosterone secretion activity. In addition, in this study it also provided the reference for a simple, quick method to screen the promoting leydig cell proliferation active components in traditional Chinese medicine (TCM).

NRhFluors: Quantitative Revealing the Interaction between Protein Homeostasis and Mitochondria Dysfunction via Fluorescence Lifetime Imaging.

Degenerative diseases are closely related to the changes of protein conformation beyond the steady state. The development of feasible tools for quantitative detection of changes in the cellular environment is crucial for investigating the process of protein conformational variations. Here, we have developed a near-infrared AIE probe based on the rhodamine fluorophore, which exhibits dual responses of fluorescence intensity and lifetime to local viscosity changes. Notably, computational analysis reveals that NRhFluors fluorescence activation is due to inhibition of the RACI mechanism in viscous environment. In the chemical regulation of rhodamine fluorophores, we found that variations of electron density distribution can effectively regulate CI states and achieve fluorescence sensitivity of NRhFluors. In addition, combined with the AggTag method, the lifetime of probe A9-Halo exhibits a positive correlation with viscosity changes. This analytical capacity allows us to quantitatively monitor protein conformational changes using fluorescence lifetime imaging (FLIM) and demonstrate that mitochondrial dysfunction leads to reduced protein expression in HEK293 cells. In summary, this work developed a set of near-infrared AIE probes activated by the RACI mechanism, which can quantitatively detect cell viscosity and protein aggregation formation, providing a versatile tool for exploring disease-related biological processes and therapeutic approaches.

Integrated cell metabolomics and network pharmacology approach deciphers the anti-testosterone deficiency mechanisms of Bushen Zhuanggu Tang.

Testicular dysfunction is distinguished by a deficiency in testosterone levels, which can be attributed to the occurrence of oxidative stress injury in Leydig cells. The empirical prescription known as Bushen Zhuanggu Tang, developed by a highly experienced traditional Chinese medicine practitioner with six decades of clinical expertize, aligns with the traditional Chinese medicine principle of "kidney governing bone". Researchers have demonstrated that the administration of BSZGT can effectively enhance testosterone production. The objective of this study is to investigate the potential anti-testicular dysfunction effects of BSZGT and elucidate its underlying mechanism in an in vitro setting. Specifically, the impact of oxidative stress induced by H2O2 on the activity and testosterone levels of Leydig cells (TM3) was examined. Furthermore, the utilization of UPLC-QE-Qrbitrap-MS enabled the identification of the involvement of BSZGT in various metabolic pathways, including arginine biosynthesis, amino acyl-tRNA biosynthesis, Alanine, aspartate and glutamine metabolism, and Citrate Cycle, through the modulation of 25 distinct metabolites. Additionally, a network pharmacological analysis was conducted to investigate the pivotal protein targets associated with the therapeutic effects of BSZGT. The findings demonstrate the identification of six key proteins (CYP19A1, CYP1B1, ALOX5, ARG1, XDH, and MPO) that play a significant role in augmenting testicular function through their involvement in the ovarian steroid production pathway. In summary, our study presents a comprehensive research methodology that combines cell metabonomics and network pharmacology to enhance the discovery of new therapeutic agents for TD.

Zika virus replication on endothelial cells and invasion into the central nervous system by inhibiting interferon ß translation.

The blood-brain barrier (BBB) is one of the tightest physical barriers to prevent pathogens from invading the central nervous system (CNS). However, the mechanism by which Zika virus (ZIKV) crossing the BBB remains unresolved. We found ZIKV induced high morbidity and mortality in newborn mice, accompanied by inflammatory injury on CNS. ZIKV was found to replicate primarily in the cortex and hippocampus in neonatal mouse brains. An in vitro model revealed that ZIKV had no impact on hBMECs permeability but led to endothelial activation, as shown by the enhancement of adhesion molecules expression and F-actin redistribution. ZIKV replication in hBMECs might be associated with the suppression of IFN-ß translation via inhibiting RPS6 phosphorylation. On the other hand, ZIKV infection induced IFN-stimulated genes (ISGs), activated the mitogen-activated protein kinase (MAPK) signaling pathway, and promoted chemokine secretion. This study provides an understanding of virus replication and transmigration across the BBB during ZIKV infection.

Exploring Asthma Mechanism of Belamcanda Chinensis by "Dose-effect Weighted Coefficient" Network Pharmacology and Experiment Validation.

BACKGROUND: Asthma is a chronic inflammatory disease of the airways that seriously endangers human health. Belamcanda chinensis (BC), a traditional Chinese medicine, has been used to counteract asthma as it has been shown to possess anti-inflammatory and regulatory immunity properties. OBJECTIVE: The study aimed to investigate the mechanisms of action of BC in the treatment of asthma; a "dose-effect weighted coefficient" network pharmacology method was established to predict potential active compounds. METHODS: Information on the components and content of BC was obtained by UPLC-QEOrbitrap- MS spectrometry. Based on BC content, oral bioavailability, and molecular docking binding energy, dose-effect weighting coefficients were constructed. With the degree greater than average as the index, a protein-protein interaction (PPI) database was used to obtain the core key targets for asthma under dose-effect weighting. GO function and KEGG pathway analyses of the core targets were performed using DAVID software. Finally, MTT and ELISA assays were used to assess the effects of active components on 16HBE cell proliferation. RESULTS: The experimental results using the 16HBE model demonstrated BC to have a potential protective effect on asthma. Network pharmacology showed SYK, AKT1, and ALOX5 to be the main key targets, and Fc epsilon RI as the promising signaling pathway. Eight components, such as tectoridin, mangiferin, luteolin, and isovitexin were the main active compounds, Finally, we analyzed the LPS-induced 16HBE proliferation of each active ingredient. Based on the activity verification study, all five predicted components promoted the proliferation of 16HBE cells. These five compounds can be used as potential quality markers for asthma. CONCLUSION: This study provides a virtual and practical method for the simple and rapid screening of active ingredients in natural products.

A transcriptomics and network pharmacology approach to elucidate the mechanism of action of geniposide on carbon tetrachloride-induced liver injury in rats.

Geniposide, the main active component of Fructus Gardeniae (FG), is known to confer protection against liver diseases. Herein we explored the hepatoprotective effects of geniposide and elucidated its molecular mechanism by transcriptome RNA-seq and network pharmacology. Liver injury was modeled by intraperitoneally injecting CCl4 (0.15% prepared with refined peanut oil) at a dose of 1.5 mL/kg thrice a week; from the second week, rats were administered geniposide (20 mg/kg or 40 mg/kg) by gavage for 6 weeks. Serum and liver samples were then collected to assess liver function indicators and inflammatory factors and to observe pathological changes in the liver. The Illumina HiSeq 4000 platform was used to obtain transcriptome data from the liver tissue of rats after geniposide administration. Core targets and pathways related to the liver protection mechanism of geniposide were further analyzed by integrating transcriptomics and network pharmacology. Differentially expressed genes (DEGs), core targets, and signaling pathways were identified by methods such as q-PCR, molecular docking, and Western blotting. We found that after geniposide administration, the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and inflammatory factors decreased in the model group, and liver injury cells be effectively repaired. RNA-seq data analysis showed that compared to control group, the model group reversed 1,451 DEGs; further, compared to model group, geniposide reversed 511 DEGs. Eight key targets, including PIK3R1, ACOX3, and EGF, were found through further analyses. Geniposide was determined to mainly regulate the PPAR signaling pathway, apoptosis signaling pathway, and MAPK signaling pathway in liver tissues. To summarize, the protective and restorative effects of geniposide on rat liver may seem to be related to its efficacy in inhibiting the activation of inflammatory pathways, thereby reducing cell apoptosis. Our findings should serve as the basis for the development of functional foods or drugs to prevent and treat liver diseases.

H1N1 influenza virus infection through NRF2-KEAP1-GCLC pathway induces ferroptosis in nasal mucosal epithelial cells.

Influenza A virus can induce nasal inflammation by stimulating the death of nasal mucosa epithelium, however, the mechanism is not clear. In this study, to study the causes and mechanisms of nasal mucosa epithelial cell death caused by Influenza A virus H1N1, we isolated and cultured human nasal epithelial progenitor cells (hNEPCs) and exposed them to H1N1 virus after leading differentiation. Then we performed high-resolution untargeted metabolomics and RNAseq analysis of human nasal epithelial cells (hNECs) infected with H1N1 virus. Surprisingly, H1N1 virus infection caused the differential expression of a large number of ferroptosis related genes and metabolites in hNECs. Furthermore, we have observed a significant reduction in Nrf2/KEAP1 expression, GCLC expression, and abnormal glutaminolysis. By constructing overexpression vector of GCLC and the shRNAs of GCLC and Keap1, we determined the role of NRF2-KEAP1-GCLC signaling pathway in H1N1 virus-induced ferroptosis. In addition, A glutaminase antagonist, JHU-083, also demonstrated that glutaminolysis can regulate the NRF2-KEAP1-GCLC signal pathway and ferroptosis. According to this study, H1N1 virus can induce the ferroptosis of hNECs via the NRF2-KEAP1-GCLC signal pathway and glutaminolysis, leading to nasal mucosal epithelial inflammation. This discovery is expected to provide an attractive therapeutic target for viral-induced nasal inflammation.

Single cell RNA sequencing unravels mechanisms underlying senescence-like phenotypes of alveolar macrophages.

Alveolar macrophages (AMs) are resident innate immune cells that play vital roles in maintaining lung physiological functions. However, the effects of aging on their dynamics, heterogeneity, and transcriptional profiles remain to be fully elucidated. Through single cell RNA sequencing (scRNA-seq), we identified CBFß as an indispensable transcription factor that ensures AM self-renewal. Intriguingly, despite transcriptome similarities of proliferating cells, AMs from aged mice exhibited reduced embryonic stem cell-like features. Aged AMs also displayed compromised DNA repair abilities, potentially leading to obstructed cell cycle progression and an elevation of senescence markers. Consistently, AMs from aged mice exhibited impaired self-renewal ability and reduced sensitivity to GM-CSF. Decreased CBFß was observed in the cytosol of AMs from aged mice. Similar senescence-like phenotypes were also found in human AMs. Taken together, these findings suggest that AMs in aged hosts demonstrate senescence-like phenotypes, potentially facilitated by the abrogated CBF ß activity.

MGA-seq: robust identification of extrachromosomal DNA and genetic variants using multiple genetic abnormality sequencing.

Genomic abnormalities are strongly associated with cancer and infertility. In this study, we develop a simple and efficient method - multiple genetic abnormality sequencing (MGA-Seq) - to simultaneously detect structural variation, copy number variation, single-nucleotide polymorphism, homogeneously staining regions, and extrachromosomal DNA (ecDNA) from a single tube. MGA-Seq directly sequences proximity-ligated genomic fragments, yielding a dataset with concurrent genome three-dimensional and whole-genome sequencing information, enabling approximate localization of genomic structural variations and facilitating breakpoint identification. Additionally, by utilizing MGA-Seq, we map focal amplification and oncogene coamplification, thus facilitating the exploration of ecDNA's transcriptional regulatory function.

JEV Infection Induces M-MDSC Differentiation Into CD3+ Macrophages in the Brain.

Japanese encephalitis virus (JEV) is one of the most important members of the flavivirus family. It is a typical zoonotic pathogen that has caused substantial social and economic losses worldwide. The relation between JEV-induced immunosuppression and inflammatory responses has not been thoroughly investigated. In this study, cells infiltrating the brain tissue of JEV-infected mice were mainly identified as monocytic myeloid-derived suppressor cells (M-MDSCs), which subsequently differentiated into CD3+ macrophages. Co-culture with T cells showed that both splenic M-MDSCs and brain infiltrated M-MDSCs isolated from JEV-infected mice inhibited T cell proliferation through ARG1 and iNOS. The splenectomy model revealed that JEV-induced M-MDSCs were mainly derived from bone marrow and migrated to the spleen and central nervous system (CNS). The results of the transcriptome analysis and IRF7-deficient mice indicated that the ZBP1-IRF7 signaling pathway stimulated by JEV RNA played a central role in the induction of M-MDSCs. M-MDSCs migrated into the CNS through the chemokine CCL2/N-CCL2 derived from astrocytes and brain infiltrated M-MDSCs differentiated into CD3+ macrophages through a mechanism mediated by M-CSF, IL-6 and IFN-γ in the brain microenvironment. These findings provide evidence for the mechanism that JEV regulates the differentiation of M-MDSCs and thereby exacerbates pathogenicity, which represents a potential therapeutic target for Japanese encephalitis (JE).

Altered gene expression in human brain microvascular endothelial cells in response to the infection of influenza H1N1 virus.

Influenza viruses not only cause respiratory illness, but also have been reported to elicit neurological manifestations following acute viral infection. The central nervous system (CNS) has a specific defense mechanism against pathogens structured by cerebral microvasculature lined with brain endothelial cells to form the blood-brain barrier (BBB). To investigate the response of human brain microvascular endothelial cells (hBMECs) to the Influenza A virus (IAV), we inoculated the cells with the A/WSN/33 (H1N1) virus. We then conducted an RNAseq experiment to determine the changes in gene expression levels and the activated disease pathways following infection. The analysis revealed an effective activation of the innate immune defense by inducing the pattern recognition receptors (PRRs). Along with the production of proinflammatory cytokines, we detected an upregulation of interferons and interferon-stimulated genes, such as IFN-ß/λ, ISG15, CXCL11, CXCL3 and IL-6, etc. Moreover, infected hBMECs exhibited a disruption in the cytoskeletal structure both on the transcriptomic and cytological levels. The RNAseq analysis showed different pathways and candidate genes associated with the neuroactive ligand-receptor interaction, neuroinflammation, and neurodegenerative diseases, together with a predicted activation of the neuroglia. Likewise, some genes linked with the mitochondrial structure and function displayed a significantly altered expression. En masse, this data supports that hBMECs could be infected by the IAV, which induces the innate and inflammatory immune response. The results suggest that the influenza virus infection could potentially induce a subsequent aggravation of neurological disorders. Supplementary Information: The online version contains supplementary material available at 10.1186/s44149-022-00053-9.