bims-mevinf 2023-04-09 papers

bims-mevinf

Biomed News

on Metabolism in viral infections

Issue of 2023‒04‒09
seven papers selected by
Alexander Ivanov

Phospholipid analysis of two influenza A virus-infected cell lines differing in their viral replication kinetics.
Emerging evidence for poxvirus-mediated unfolded protein response: Lumpy skin disease virus maintains self-replication by activating PERK and IRE1 signaling.
Potential use of the cholesterol transfer inhibitor U18666A as an antiviral drug for research on various viral infections.
Isoliquiritigenin inhibits virus replication and virus-mediated inflammation via NRF2 signaling.
SARS-CoV-2 Inhibits NRF2-Mediated Antioxidant Responses in Airway Epithelial Cells and in the Lung of a Murine Model of Infection.
Metabolomic Profiling of Lungs from Mice Reveals the Variability of Metabolites in Pneumocystis Infection and the Metabolic Abnormalities in BAFF-R-Deficient Mice.
Metabolic dysregulation impairs lymphocyte function during severe SARS-CoV-2 infection.

Arch Virol. 2023 Apr 07. 168(5): 132

Phospholipid analysis of two influenza A virus-infected cell lines differing in their viral replication kinetics.

Kohei Kawabata, Yuichiro Sato, Takanori Kubo, Akira Tokumura, Hiroyuki Nishi, Kinjiro Morimoto.

Fluctuations in phospholipid composition in infected cells during influenza A virus replication were analyzed using two different susceptible host cell lines: H292 cells, exhibiting a rapid cytopathic effect, and A549 cells, exhibiting a retarded cytopathic effect. Microarray analysis demonstrated that A549 cells recognized influenza A virus invasion, expression of pathogen recognition genes was affected, and antiviral genes were activated. On the other hand, H292 cells did not display such an antiviral state, and in these cells, rapid virus amplification and a rapid cytopathic effect were observed. Levels of ceramide, diacylglycerol, and lysolipids were higher in virus-infected cells than in the corresponding mock-infected cells at the later stages of infection. The accumulation of these lipids in IAV-infected cells occurred together with viral replication. The relationship between the characteristic features of ceramide, diacylglycerol, and lysolipid in the plasma membrane, where enveloped viruses are released, and their role in viral envelope formation are discussed. Our results indicate that viral replication disturbs cellular lipid metabolism, with consequences for viral replication kinetics.

DOI: https://doi.org/10.1007/s00705-023-05766-x
FASEB J. 2023 05;37(5): e22902

Emerging evidence for poxvirus-mediated unfolded protein response: Lumpy skin disease virus maintains self-replication by activating PERK and IRE1 signaling.

Jinlong Tan, Yinju Liu, Fan Yang, Guohua Chen, Yongxiang Fang, Xiaobing He, Zhongzi Lou, Huaijie Jia, Zhizhong Jing, Weike Li.

  The monkeypox epidemic has attracted global attention to poxviruses. The cytoplasmic replication of poxviruses requires extensive protein synthesis, challenging the capacity of the endoplasmic reticulum (ER). However, the role of the ER in the life cycle of poxviruses is unclear. In this study, we demonstrate that infection with the lumpy skin disease virus (LSDV), a member of the poxvirus family, causes ER stress in vivo and in vitro, further facilitating the activation of the unfolded protein response (UPR). Although UPR activation aids in the restoration of the cellular environment, its significance in the LSDV life cycle remains unclear. Furthermore, the significance of ER imbalance for viral replication is also unknown. We show that LSDV replication is hampered by an unbalanced ER environment. In addition, we verify that the LSDV replication depends on the activation of PERK-eIF2α and IRE1-XBP1 signaling cascades rather than ATF6, implying that global translation and reduced XBP1 cleavage are deleterious to LSDV replication. Taken together, these findings indicate that LSDV is involved in the repression of global translational signaling, ER chaperone transcription, and ATF6 cleavage from the Golgi into the nucleus, thereby maintaining cell homeostasis; moreover, PERK and IRE1 activation contribute to LSDV replication. Our findings suggest that targeting UPR elements may be applied in response to infection from LSDV or even other poxviruses, such as monkeypox.

Keywords:  cell signaling; endoplasmic reticulum stress; lumpy skin disease virus; poxvirus; unfolded protein response

DOI:  https://doi.org/10.1096/fj.202300028R
Microb Pathog. 2023 Apr 01. pii: S0882-4010(23)00129-8. [Epub ahead of print]179 106096

Potential use of the cholesterol transfer inhibitor U18666A as an antiviral drug for research on various viral infections.

Marjan Assefi, Reza Bijan Rostami, Menooa Ebrahimi, Mana Altafi, Pooya M Tehrany, Haider Kamil Zaidan, Bashar Zuhair Talib Al-Naqeeb, Meead Hadi, Saman Yasamineh, Omid Gholizadeh.

  Cholesterol plays critical functions in arranging the biophysical attributes of proteins and lipids in the plasma membrane. For various viruses, an association with cholesterol for virus entrance and/or morphogenesis has been demonstrated. Therefore, the lipid metabolic pathways and the combination of membranes could be targeted to selectively suppress the virus replication steps as a basis for antiviral treatment. U18666A is a cationic amphiphilic drug (CAD) that affects intracellular transport and cholesterol production. A robust tool for investigating lysosomal cholesterol transfer and Ebola virus infection is an androstenolone derived termed U18666A that suppresses three enzymes in the cholesterol biosynthesis mechanism. In addition, U18666A inhibited low-density lipoprotein (LDL)-induced downregulation of LDL receptor and triggered lysosomal aggregation of cholesterol. According to reports, U18666A inhibits the reproduction of baculoviruses, filoviruses, hepatitis, coronaviruses, pseudorabies, HIV, influenza, and flaviviruses, as well as chikungunya and flaviviruses. U18666A-treated viral infections may act as a novel in vitro model system to elucidate the cholesterol mechanism of several viral infections. In this article, we discuss the mechanism and function of U18666A as a potent tool for studying cholesterol mechanisms in various viral infections.

Keywords:  Anti-viral drug; Cholesterol; NPC1; U18666A; Viral infection

DOI:  https://doi.org/10.1016/j.micpath.2023.106096
Phytomedicine. 2023 Mar 26. pii: S0944-7113(23)00147-2. [Epub ahead of print]114 154786

Isoliquiritigenin inhibits virus replication and virus-mediated inflammation via NRF2 signaling.

Haojia Wang, Xin Jia, Meiqi Zhang, Cuiqin Cheng, Xue Liang, Xuejiao Wang, Fang Xie, Jinyong Wang, Yanli Yu, Yuting He, Qiutong Dong, Yao Wang, Anlong Xu.

  BACKGROUND: The transcription factor NRF2 is a master redox switch that regulates the cellular antioxidant response. However, recent advances have revealed new roles for NRF2, including the regulation of antiviral responses to various viruses, suggesting that pharmacological NRF2-activating agents may be a promising therapeutic drug for viral diseases. Isoliquiritigenin (ISL), a chalcone isolated from liquorice (Glycyrrhizae Radix) root, is reported to be a natural NRF2 agonist and has has antiviral activities against HCV (hepatitis C virus) and IAV (influenza A virus). However, the spectrum of antiviral activity and associated mechanism of ISL against other viruses are not well defined.PURPOSE: This study investigated the antiviral activity and underlying mechanism of ISL against vesicular stomatitis virus (VSV), influenza A virus (H1N1), encephalomyocarditis virus (EMCV), herpes simplex virus type 1 (HSV-1).
METHODS: We evaluated the antiviral activity of ISL against VSV, H1N1, EMCV, and HSV-1 using flow cytometry and qRT-PCR analysis. RNA sequencing and bioinformatic analysis were performed to investigate the potential antiviral mechanism of ISL. NRF2 knockout cells were used to investigate whether NRF2 is required for the antiviral activity of ISL. The anti-apoptosis and anti-inflammatory activities of ISL were further measured by counting cell death ratio and assessing proinflammatory cytokines expression in virus-infected cells, respectively. In addition, we evaluated the antiviral effect of ISL in vivo by measuring the survival rate, body weights, histological analysis, viral load, and cytokine expression in VSV-infected mouse model.
RESULTS: Our data demonstrated that ISL effectively suppressed VSV, H1N1, HSV-1, and EMCV replication in vitro. The antiviral activity of ISL could be partially impaired in NRF2-deficient cells. Virus-induced cell death and proinflammatory cytokines were repressed by ISL. Finally, we showed that ISL treatment protected mice against VSV infection by reducing viral titers and suppressing the expression of inflammatory cytokines in vivo.
CONCLUSION: These findings suggest that ISL has antiviral and anti-inflammatory effects in virus infections, which are associated with its ability to activate NRF2 signaling, thus indicating that ISL has the potential to serve as an NRF2 agonist in the treatment of viral diseases.

Keywords:  Antiviral Activity; Inflammation; Isoliquiritigenin; NRF2

DOI:  https://doi.org/10.1016/j.phymed.2023.154786
Microbiol Spectr. 2023 Apr 06. e0037823

SARS-CoV-2 Inhibits NRF2-Mediated Antioxidant Responses in Airway Epithelial Cells and in the Lung of a Murine Model of Infection.

Yue Qu, Aline Haas de Mello, Dorothea R Morris, Yava L Jones-Hall, Teodora Ivanciuc, Rachel A Sattler, Slobodan Paessler, Vineet D Menachery, Roberto P Garofalo, Antonella Casola.

  Several viruses have been shown to modulate the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2), the master regulator of redox homeostasis. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic, also seems to disrupt the balance between oxidants and antioxidants, which likely contributes to lung damage. Using in vitro and in vivo models of infection, we investigated how SARS-CoV-2 modulates the transcription factor NRF2 and its dependent genes, as well as the role of NRF2 during SARS-CoV-2 infection. We found that SARS-CoV-2 infection downregulates NRF2 protein levels and NRF2-dependent gene expression in human airway epithelial cells and in lungs of BALB/c mice. Reductions in cellular levels of NRF2 seem to be independent of proteasomal degradation and the interferon/promyelocytic leukemia (IFN/PML) pathway. Furthermore, lack of the Nrf2 gene in SARS-CoV-2-infected mice exacerbates clinical disease, increases lung inflammation, and is associated with a trend toward increased lung viral titers, indicating that NRF2 has a protective role during this viral infection. In summary, our results suggest that SARS-CoV-2 infection alters the cellular redox balance by downregulating NRF2 and its dependent genes, which exacerbates lung inflammation and disease, therefore, suggesting that the activation of NRF2 could be explored as therapeutic approach during SARS-CoV-2 infection. IMPORTANCE The antioxidant defense system plays a major function in protecting the organism against oxidative damage caused by free radicals. COVID-19 patients often present with biochemical characteristics of uncontrolled pro-oxidative responses in the respiratory tract. We show herein that SARS-CoV-2 variants, including Omicron, are potent inhibitors of cellular and lung nuclear factor erythroid 2-related factor 2 (NRF2), the master transcription factor that controls the expression of antioxidant and cytoprotective enzymes. Moreover, we show that mice lacking the Nrf2 gene show increased clinical signs of disease and lung pathology when infected with a mouse-adapted strain of SARS-CoV-2. Overall, this study provides a mechanistic explanation for the observed unbalanced pro-oxidative response in SARS-CoV-2 infections and suggests that therapeutic strategies for COVID-19 may consider the use of pharmacologic agents that are known to boost the expression levels of cellular NRF2.

Keywords:  COVID-19; NRF2; Nrf2-deficient mice; SARS-CoV-2; antioxidant enzymes

DOI:  https://doi.org/10.1128/spectrum.00378-23
J Inflamm Res. 2023 ;16 1357-1373

Metabolomic Profiling of Lungs from Mice Reveals the Variability of Metabolites in Pneumocystis Infection and the Metabolic Abnormalities in BAFF-R-Deficient Mice.

Heng-Mo Rong, Han-Yu-Jie Kang, Zhao-Hui Tong.

  Purpose: The incidence of Pneumocystis pneumonia (PCP) in patients without human immunodeficiency virus (HIV) has been increasing. In this study, we aimed to investigate the metabolic changes in Pneumocystis infection and the metabolic abnormalities in B-cell-activating factor receptor (BAFF-R)-deficient mice with Pneumocystis infection.Methods: The important function of B cells during Pneumocystis infection is increasingly recognized. In this study, a Pneumocystis-infected mouse model was constructed in BAFF-R-/- mice and wild-type (WT) mice. Lungs of uninfected WT C57BL/6, WT Pneumocystis-infected, and BAFF-R-/- Pneumocystis-infected mice were used for metabolomic analyses to compare the metabolomic profiles among the groups, with the aim of exploring the metabolic influence of Pneumocystis infection and the influence of mature B-cell deficiency during infection.
Results: The results indicated that many metabolites, mainly lipids and lipid-like molecules, were dysregulated in Pneumocystis-infected WT mice compared with uninfected WT C57BL/6 mice. The data also demonstrated significant changes in tryptophan metabolism, and the expression levels of key enzymes of tryptophan metabolism, such as indoleamine 2,3-dioxygenase 1 (IDO1), were significantly upregulated. In addition, B-cell development and function might be associated with lipid metabolism. We found a lower level of alitretinoin and the abnormalities of fatty acid metabolism in BAFF-R-/- Pneumocystis-infected mice. The mRNA levels of enzymes associated with fatty acid metabolism in the lung were upregulated in BAFF-R-/- Pneumocystis-infected mice and positively correlated with the level of IL17A, thus suggesting that the abnormalities of fatty acid metabolism may be associated with greater inflammatory cell infiltration in the lung tissue of BAFF-R-/- Pneumocystis-infected mice compared with the WT Pneumocystis-infected mice.
Conclusion: Our data revealed the variability of metabolites in Pneumocystis-infected mice, suggesting that the metabolism plays a vital role in the immune response to Pneumocystis infection.

Keywords:  B lymphocytes; Pneumocystis pneumonia; inflammation; metabolomics

DOI:  https://doi.org/10.2147/JIR.S394608
Commun Biol. 2023 Apr 07. 6(1): 374

Metabolic dysregulation impairs lymphocyte function during severe SARS-CoV-2 infection.

Sanjeev Gurshaney, Anamaria Morales-Alvarez, Kevin Ezhakunnel, Andrew Manalo, Thien-Huong Huynh, Jun-Ichi Abe, Nhat-Tu Le, Daniela Weiskopf, Alessandro Sette, Daniel S Lupu, Stephen J Gardell, Hung Nguyen.

Cellular metabolic dysregulation is a consequence of SARS-CoV-2 infection that is a key determinant of disease severity. However, how metabolic perturbations influence immunological function during COVID-19 remains unclear. Here, using a combination of high-dimensional flow cytometry, cutting-edge single-cell metabolomics, and re-analysis of single-cell transcriptomic data, we demonstrate a global hypoxia-linked metabolic switch from fatty acid oxidation and mitochondrial respiration towards anaerobic, glucose-dependent metabolism in CD8+Tc, NKT, and epithelial cells. Consequently, we found that a strong dysregulation in immunometabolism was tied to increased cellular exhaustion, attenuated effector function, and impaired memory differentiation. Pharmacological inhibition of mitophagy with mdivi-1 reduced excess glucose metabolism, resulting in enhanced generation of SARS-CoV-2- specific CD8+Tc, increased cytokine secretion, and augmented memory cell proliferation. Taken together, our study provides critical insight regarding the cellular mechanisms underlying the effect of SARS-CoV-2 infection on host immune cell metabolism, and highlights immunometabolism as a promising therapeutic target for COVID-19 treatment.

DOI: https://doi.org/10.1038/s42003-023-04730-4