bims-mevinf 2023-12-24 papers

Intervirology. 2023 Dec 15.

GSK-3β as a potential coordinator of anabolic and catabolic pathways in hepatitis C virus insulin resistance.

INTRODUCTION: Chronic HCV infection results in insulin resistance (IR) through interaction of pathways for glucose homeostasis, insulin signaling, and autophagy. Not known is how soon the pathways are activated, and how IR is related to the signals generated by catabolic and anabolic conditions occurring in infected cells. We have extended our studies to a cell culture system mimicking acute infection and to downstream pathways involving energy-sensor AMPK and nutrient-sensor mTOR that are active in catabolic and anabolic processes within the infected cells.
METHODS: Huh7 liver cells were infected with HCV. We performed proteomics analysis of key proteins in infected cells by western blotting and IP experiments, with or without interferon-α exposure.
RESULTS: We show that IRS-1 Ser312, Beclin-1, protein conjugate Atg12-Atg5 or GS Ser641 are upregulated early in infection by activating the same pathways utilized for persistent infection; Bcl-XL, an inhibitor of both autophagy and apoptosis, is present in a core-complex with IRS-1 Ser312 and Beclin-1 during progression of IR; AMPK level remains the same in infected cells where it is activated by phosphorylation at Thr172 concomitant with increased autophagy, a hallmark of catabolic conditions; an mTOR level that promotes anabolism is increased rather than decreased under an expanded autophagy; hypophosphorylation of translational repressor 4E-BP1 downstream of mTOR is suggestive of reduced protein synthesis; and β-catenin is upregulated but not phosphorylated suggesting indirectly our previous contention that its kinase, GSK-3β, is mostly in an inactive state.
DISCUSSION/CONCLUSION: We report that in the development of IR following chronic infection, anabolic and catabolic pathways are activated early, and the metabolic interaction occurs possibly in a core-complex with IRS-1 Ser312, Beclin-1 and autophagy inhibitor BcL-XL. Induction of autophagy is usually controlled by a two-edged mechanism acting in opposition under anabolic and catabolic conditions by AMPK/mTOR/4E-BP1 pathways with GSK-3β mediated feed-back loops. However, we observed that an up-regulation of mTOR along with an up-regulation of AMPK caused by HCV infection is a deviation from the normal scenario described above which might be of therapeutic interest.

DOI: https://doi.org/10.1159/000535787

mBio. 2023 Dec 20. e0303123

Cytomegalovirus-induced inactivation of TSC2 disrupts the coupling of fatty acid biosynthesis to glucose availability resulting in a vulnerability to glucose starvation.

Matthew H Raymonda, Irene Rodríguez-Sánchez, Xenia L Schafer, Leonid Smorodintsev-Schiller, Isaac S Harris, Joshua Munger.

IMPORTANCE: Viruses modulate host cell metabolism to support the mass production of viral progeny. For human cytomegalovirus, we find that the viral UL38 protein is critical for driving these pro-viral metabolic changes. However, our results indicate that these changes come at a cost, as UL38 induces an anabolic rigidity that leads to a metabolic vulnerability. We find that UL38 decouples the link between glucose availability and fatty acid biosynthetic activity. Normal cells respond to glucose limitation by down-regulating fatty acid biosynthesis. Expression of UL38 results in the inability to modulate fatty acid biosynthesis in response to glucose limitation, which results in cell death. We find this vulnerability in the context of viral infection, but this linkage between fatty acid biosynthesis, glucose availability, and cell death could have broader implications in other contexts or pathologies that rely on glycolytic remodeling, for example, oncogenesis.

Keywords: TSC2; UL38; fatty acid biosynthesis; glycolysis; human cytomegalovirus; lipogenesis; metabolism

DOI: https://doi.org/10.1128/mbio.03031-23

Vet Res. 2023 Dec 20. 54(1): 124

Vidofludimus inhibits porcine reproductive and respiratory syndrome virus infection by targeting dihydroorotate dehydrogenase.

Yuanqi Yang, Yanni Gao, Lujie Zhang, Xing Liu, Yangyang Sun, Juan Bai, Ping Jiang.

Porcine reproductive and respiratory syndrome virus (PRRSV) infection has caused huge economic losses in global swine industry over the last 37 years. PRRSV commercial vaccines are not effective against all epidemic PRRSV strains. In this study we performed a high-throughput screening (HTS) of an FDA-approved drug library, which contained 2339 compounds, and found vidofludimus (Vi) could significantly inhibits PRRSV replication in Marc-145 cells and primary porcine alveolar macrophages (PAMs). Compounds target prediction, molecular docking analysis, and target protein interference assay showed that Vi interacts with dihydroorotate dehydrogenase (DHODH), a rate-limiting enzyme in the de novo pyrimidine synthesis pathway. Furthermore, PRRSV infection was restored in the presence of excess uridine and cytidine which promote pyrimidine salvage, or excess orotate which is the product of DHODH in the de novo pyrimidine biosynthesis pathway, thus confirming that the antiviral effect of Vi against PRRSV relies on the inhibition of DHODH. In addition, Vi also has antiviral activity against Seneca virus A (SVA), encephalomyocarditis virus (EMCV), porcine epidemic diarrhea virus (PEDV), and pseudorabies virus (PRV) in vitro. These findings should be helpful for developing a novel prophylactic and therapeutic strategy against PRRSV and other swine viral infections.

Keywords: PRRSV infection; Vidofludimus; antiviral; broad-spectrum; dihydroorotate dehydrogenase

DOI: https://doi.org/10.1186/s13567-023-01251-0

Front Immunol. 2023 ;14 1268854

Lipid compartments and lipid metabolism as therapeutic targets against coronavirus.

Daniella Cesar-Silva, Filipe S Pereira-Dutra, Ana Lucia Moraes Giannini, Clarissa M Maya-Monteiro, Cecília Jacques G de Almeida.

Lipids perform a series of cellular functions, establishing cell and organelles' boundaries, organizing signaling platforms, and creating compartments where specific reactions occur. Moreover, lipids store energy and act as secondary messengers whose distribution is tightly regulated. Disruption of lipid metabolism is associated with many diseases, including those caused by viruses. In this scenario, lipids can favor virus replication and are not solely used as pathogens' energy source. In contrast, cells can counteract viruses using lipids as weapons. In this review, we discuss the available data on how coronaviruses profit from cellular lipid compartments and why targeting lipid metabolism may be a powerful strategy to fight these cellular parasites. We also provide a formidable collection of data on the pharmacological approaches targeting lipid metabolism to impair and treat coronavirus infection.

Keywords: SARS-CoV-2; caveolae; caveolin; coronavirus; inflammation; lipid droplets; lipid metabolism; lipid nanodomains

DOI: https://doi.org/10.3389/fimmu.2023.1268854

Front Vet Sci. 2023 ;10 1171750

Plasma metabonomics of classical swine fever virus-infected pigs.

Jiedan Liao, Wenshuo Hu, Weijun Wang, Xinyan Wang, Shu Yu, Xinni Niu, Wenhui Zhu, Bolun Zhou, Yiwan Song, Weijun Zeng, Zhimin Lu, Jinding Chen.

Classical swine fever (CSF) is an infectious disease caused by Classical swine fever virus (CSFV), which is characterized by depression, high fever, extensive skin bleeding, leukopenia, anorexia, alternating constipation, and diarrhea. Hemorrhagic infarction of the spleen is the main characteristic pathological change following CSFV infection. Large-scale outbreaks of CSF are rare in China and are mainly distributed regionally. The clinical symptoms of CSF are not obvious, and show variation from typical to atypical symptoms, which makes diagnosis based on clinical symptoms and pathology challenging. In recent years, the incidence of CSF-immunized pig farms in China has increased and new CSFV gene subtypes have appeared, posing new challenges to the prevention and control of CSF in China. Changes in metabolites caused by viral infection reflect the pathogenic process. Metabonomics can reveal the trace metabolites of organisms; however, plasma metabonomics of CSFV-infected pigs have rarely been investigated. Therefore, we used an established pig CSFV infection model to study changes in plasma metabolites. The results showed significant differences in forty-five plasma metabolites at different time periods after CSFV infection in pigs, with an increase in twenty-five metabolites and a decrease in twenty metabolites. These changed metabolites were mainly attributed to the tricarboxylic acid cycle, amino acid cycle, sugar metabolism, and fat metabolism. Thirteen metabolic pathways changed significantly in CSFV-infected pigs, including tricarboxylic acid cycle, inositol phosphate metabolism, glycine, serine and threonine metabolism,lysine degradation, alanine, aspartate and glutamic acid metabolism, pantothenate and CoA biosynthesis, β-alanine metabolism, lysine degradation, arginine and proline metabolism, glycerolipid metabolism, phenylalanine metabolism, arachidonic acid metabolism, linoleic acid metabolism. Among these, changes in fatty acid biosynthesis and metabolism occurred at all time periods post-infection. These results indicate that CSFV infection in pigs could seriously alter metabolic pathways.

Keywords: classical swine fever virus; heat map; metabolic pathway; metabonomics; tricarboxylic acid cycle

DOI: https://doi.org/10.3389/fvets.2023.1171750

mBio. 2023 Dec 19. e0214523

Host IP3R channels are dispensable for rotavirus Ca2+ signaling but critical for intercellular Ca2+ waves that prime uninfected cells for rapid virus spread.

Jacob L Perry, Francesca J Scribano, John T Gebert, Kristen A Engevik, Jenna M Ellis, Joseph M Hyser.

IMPORTANCE: Many viruses exploit host Ca2+ signaling to facilitate their replication; however, little is known about how Ca2+ signals from different host and viral channels contribute to the overall dysregulation of Ca2+ signaling or promote virus replication. Using cells lacking IP3R, a host ER Ca2+ channel, we delineated intracellular Ca2+ signals within virus-infected cells and intercellular Ca2+ waves (ICWs), which increased Ca2+ signaling in neighboring, uninfected cells. In infected cells, IP3R was dispensable for rotavirus-induced Ca2+ signaling and replication, suggesting the rotavirus NSP4 viroporin supplies these signals. However, IP3R-mediated ICWs increase rotavirus replication kinetics and spread, indicating that the Ca2+ signals from the ICWs may prime nearby uninfected cells to better support virus replication upon eventual infection. This "pre-emptive priming" of uninfected cells by exploiting host intercellular pathways in the vicinity of virus-infected cells represents a novel mechanism for viral reprogramming of the host to gain a replication advantage.

Keywords: calcium signaling; live imaging; purinergic signaling; replication; rotavirus

DOI: https://doi.org/10.1128/mbio.02145-23

Eur J Pharmacol. 2023 Dec 17. pii: S0014-2999(23)00785-9. [Epub ahead of print] 176271

Luteolin-7-O-glucoside promotes macrophage release of IFN-β by maintaining mitochondrial function and corrects the disorder of glucose metabolism during RSV infection.

Weifeng Li, Xuan Wang, Yanzhen Chen, Yali Ding, Xiaoyin Ling, Bin Yuan, Jialei Tao.

Respiratory syncytial virus (RSV) pneumonia is the main cause of acute bronchiolitis in infants. Luteolin-7-O-glucoside (LUT-7G) is a natural flavonoid, which exists in a variety of plants and has the potential to treat viral pneumonia. We established RSV pneumonia mouse models and RSV-infected cell models. Clodronate liposomes were used to deplete macrophages. We used HE staining and immunohistochemistry to determine inflammatory damage and virus replication. We detected the expression levels of inflammatory factors and IFN-β through qPCR and ELISA. JC-1 kit was used for detecting the cell mitochondrial Membrane potential (MMP). ROS, SOD, and MDA kits were used for detecting intracellular oxidative stress damage. Metabolites of TCA in lung tissue and serum of mice were detected by GC-MS. Pharmacodynamic studies have shown that intervention with LUT-7G can alleviate lung tissue damage caused by RSV infection, inhibit RSV replication, and downregulate TNF-α, IL-1β, and IL-6 mRNA expression. LUT-7G upregulated the IFN-β content and the expression of IFN-β, ISG15, and OAS1 mRNA. In vitro, LUT-7G inhibited RSV-induced cell death, reversed the RSV-induced decrease of MMP and decreased intracellular oxidative stress. Target metabonomics showed that RSV infection upregulated the levels of glycolysis and TCA metabolites in lung tissue and serum, while LUT-7G could improve the disorder of glucose metabolism. The results indicate that LUT-7G can promote the release of IFN-β in the lung, alleviate inflammatory damage, and inhibit RSV replication during RSV infection. These effects may be achieved by protecting the mitochondrial function of alveolar macrophages and correcting the disorder of glucose metabolism.

Keywords: Alveolar macrophage; IFN-β; Luteolin-7-O-Glucoside; Respiratory syncytial virus; Tricarboxylic acid cycle

DOI: https://doi.org/10.1016/j.ejphar.2023.176271

J Gen Virol. 2023 Dec;104(12):

Integrated metabolomics and transcriptomics analyses reveal metabolic responses to TGEV infection in porcine intestinal epithelial cells.

Shuoshuo Zhang, Yanan Cao, Chao Xu, Guangzheng Wang, Yanjie Huang, Wenbin Bao, Shuai Zhang.

Transmissible gastroenteritis virus (TGEV) is a coronavirus that infects piglets with severe diarrhoea, vomiting, dehydration, and even death, causing huge economic losses to the pig industry. The underlying pathogenesis of TGEV infection and the effects of TGEV infection on host metabolites remain poorly understood. To investigate the critical metabolites and regulatory factors during TGEV infection in intestinal porcine epithelial cells (IPEC-J2), we performed metabolomic and transcriptomic analyses of TGEV-infected IPEC-J2 cells by LC/MS and RNA-seq techniques. A total of 87 differential metabolites and 489 differentially expressed genes were detected. A series of metabolites and candidate genes from glutathione metabolism and AMPK signalling pathway were examined through combined analysis of metabolome and transcriptome. We found glutathione peroxidase 3 (GPX3) is markedly reduced after TGEV infection, and a significant negative correlation between AMPK signalling pathway and TGEV infection. Exogenous addition of the AMPK activator COH-SR4 significantly downregulates stearoyl coenzyme A (SCD1) mRNA and inhibits TGEV replication; while exogenous GSK-690693 significantly promotes TGEV infection by inhibiting AMPK signalling pathway. In summary, our study provides insights into the key metabolites and regulators for TGEV infection from the metabolome and transcriptome perspective, which will offer promising antiviral metabolic and molecular targets and enrich the understanding of the existence of a similar mechanism in the host.

Keywords: APMK signaling pathway; IPEC-J2 cells; TGEV; metabolome; transcriptome

DOI: https://doi.org/10.1099/jgv.0.001942

Virol J. 2023 Dec 19. 20(1): 305

Untargeted metabolomics of the intestinal tract of DEV-infected ducks.

Haiqing Cai, Xia Yang, Yunyun Yang, Yi Feng, Anlin Wen, Ying Yang, Ming Wen, Deyuan Ou.

INTRODUCTION: Duck enteritis virus (DEV) mainly causes infectious diseases characterized by intestinal haemorrhage, inflammation and parenchymal organ degeneration in ducks and other poultry. However, the mechanism by which it causes intestinal damage in ducks is not well understood. Metabolomics can provide an in-depth understanding of the full complexity of the disease.
METHODS: In this study, 24 clinically healthy green-shell ducks (weight 1.5 kg ± 20 g) were randomly divided into 2 groups (experimental group, 18; control group, 6). The experimental group was intramuscularly injected with 0.2 mL of DEV virus in solution (TCID50 3.16 × 108 PFU/mL), and the control group was injected with 0.2 mL of sterile normal saline. Duck duodenum and ileum tissue samples were collected at 66 h, 90 h and 114 h post-injection (12 h of fasting before killing), and metabolomics analysis of duck duodenum and ileum tissues at the three time points (66, 90, 114 h) was performed by liquid chromatography-mass spectrometry (LC-MS) to screen for and analyse the potential differentiated metabolites and related signalling pathways.
RESULTS: Screening was performed in the positive/negative mode (Pos: Positive ion mode; the ionization of substances at the ion source with positive ions such as H+, NH4+, Na+ and K+; Neg: Negative ion mode; the ionization of substances at the ion source with negative ions such as Cl-, OAc-), and compound abundance was compared to that in the control group. The total number of differentially abundant compounds in the duodenum at 66 h, 90 h and 114 h of DEV infection gradually increased, and metabolites such as cytidine, 2'-deoxyriboside and 4-guanidinobutyric acid were differentially abundant metabolites common to all three time periods. The metabolic pathways related to inflammatory response and immune response were tryptophan acid metabolism, cysteine-methionine metabolism, histidine metabolism and other amino acid metabolism and fat metabolism. Among them, the metabolic pathways with more differentially abundant metabolites were amino acid biosynthesis, cysteine and methionine metabolism, tryptophan metabolism, unsaturated fatty acid biosynthesis and purine metabolism, and the metabolic pathways with more enrichment factors were the IgA-related intestinal immune network pathway and lysosome pathway. Compared with the control group, there were 16 differentially abundant metabolites in the ileum tissue of DEV-infected ducks at 66 h of infection, 52 at 90 h of infection, and 40 at 14 h of infection with TD114. The metabolic pathways with more enriched differentially abundant metabolites were pyrimidine metabolism, tyrosine metabolism, phenylalanine metabolism and tryptophan biosynthesis. The metabolic pathways with the most enrichment factors were the mTOR signalling pathway, ferroptosis pathway, tryptophan metabolism pathway and caffeine metabolism pathway.
CONCLUSION: Comparative analysis showed that the number of differentially abundant metabolites in the duodenum and ileum differed to some extent after DEV infection, with significantly more differentially abundant metabolites in duodenal tissues and fewer in ileal tissues; after DEV infection, the highest number of differentially abundant metabolites was obtained at 114 h of DEV infection, followed by the second highest at 90 h of infection and the lowest at 66 h of infection. The common differentially abundant metabolites in duodenal and ileal tissues were prostaglandins, arachidonic acid, and arachidonic ethanolamine. The main metabolic pathways in the duodenum were the IgA-associated intestinal immune network pathway and the lysosomal pathway, and the metabolic pathways with more enriched factors in the ileum were the mTOR signalling pathway, the ferroptosis pathway, and the tryptophan metabolism pathway.

Keywords: Differentially abundant metabolites; Duck; Duck enteritis virus; Gut; Nontargeted metabolomics

DOI: https://doi.org/10.1186/s12985-023-02266-x