scholarly journals Inhibiting ACSL1-Related Ferroptosis Restrains Murine Coronavirus Infection

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2383
Author(s):  
Huawei Xia ◽  
Zeming Zhang ◽  
Fuping You

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We utilized murine macrophages and a C57BL/6 mice intranasal infection model to address this. In primary macrophages, the ferroptosis inhibitor inhibited viral propagation, inflammatory cytokines released, and cell syncytia formed after MHV-A59 infection. In the mouse model, we found that in vivo administration of liproxstatin-1 ameliorated lung inflammation and tissue injuries caused by MHV-A59 infection. To find how MHV-A59 infection influenced the expression of ferroptosis-related genes, we performed RNA-seq in primary macrophages and found that MHV-A59 infection upregulates the expression of the acyl-CoA synthetase long-chain family member 1 (ACSL1), a novel ferroptosis inducer. Using ferroptosis inhibitors and a TLR4 inhibitor, we showed that MHV-A59 resulted in the NF-kB-dependent, TLR4-independent ACSL1 upregulation. Accordingly, ACSL1 inhibitor Triacsin C suppressed MHV-A59-infection-induced syncytia formation and viral propagation in primary macrophages. Collectively, our study indicates that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serve as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection.

2021 ◽  
Author(s):  
Huawei Xia ◽  
Zeming Zhang ◽  
Fuping You

Murine hepatitis virus strain A59 (MHV-A59) belongs to the β-coronavirus and is considered as a representative model for studying coronavirus infection. MHV-A59 was shown to induce pyroptosis, apoptosis and necroptosis of infected cells, especially the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59, is unknown. Here, we demonstrate inhibiting ferroptosis suppresses MHV-A59 infection. MHV-A59 infection upregulates the expression of Acsl1, a novel ferroptosis inducer. MHV-A59 upregulates Acsl1 expression depending on the NF-kB activation, which is TLR4-independent. Ferroptosis inhibitor inhibits viral propagation, inflammatory cytokines release and MHV-A59 infection induced cell syncytia formation. ACSL1 inhibitor Triacsin C suppresses MHV-A59 infection induced syncytia formation and viral propagation. In vivo administration of liproxstatin-1 ameliorates lung inflammation and tissue injuries caused by MHV-A59 infection. Collectively, these results indicate that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serves as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection.


2021 ◽  
Vol 17 (6) ◽  
pp. e1009644
Author(s):  
Liliana Echavarría-Consuegra ◽  
Georgia M. Cook ◽  
Idoia Busnadiego ◽  
Charlotte Lefèvre ◽  
Sarah Keep ◽  
...  

Coronavirus infection induces the unfolded protein response (UPR), a cellular signalling pathway composed of three branches, triggered by unfolded proteins in the endoplasmic reticulum (ER) due to high ER load. We have used RNA sequencing and ribosome profiling to investigate holistically the transcriptional and translational response to cellular infection by murine hepatitis virus (MHV), often used as a model for the Betacoronavirus genus to which the recently emerged SARS-CoV-2 also belongs. We found the UPR to be amongst the most significantly up-regulated pathways in response to MHV infection. To confirm and extend these observations, we show experimentally the induction of all three branches of the UPR in both MHV- and SARS-CoV-2-infected cells. Over-expression of the SARS-CoV-2 ORF8 or S proteins alone is itself sufficient to induce the UPR. Remarkably, pharmacological inhibition of the UPR greatly reduced the replication of both MHV and SARS-CoV-2, revealing the importance of this pathway for successful coronavirus replication. This was particularly striking when both IRE1α and ATF6 branches of the UPR were inhibited, reducing SARS-CoV-2 virion release (~1,000-fold). Together, these data highlight the UPR as a promising antiviral target to combat coronavirus infection.


2001 ◽  
Vol 75 (6) ◽  
pp. 2792-2802 ◽  
Author(s):  
Dawn K. Krueger ◽  
Sean M. Kelly ◽  
Daniel N. Lewicki ◽  
Rosanna Ruffolo ◽  
Thomas M. Gallagher

ABSTRACT The prototype JHM strain of murine hepatitis virus (MHV) is an enveloped, RNA-containing coronavirus that has been selected in vivo for extreme neurovirulence. This virus encodes spike (S) glycoproteins that are extraordinarily effective mediators of intercellular membrane fusion, unique in their ability to initiate fusion even without prior interaction with the primary MHV receptor, a murine carcinoembryonic antigen-related cell adhesion molecule (CEACAM). In considering the possible role of this hyperactive membrane fusion activity in neurovirulence, we discovered that the growth of JHM in tissue culture selected for variants that had lost murine CEACAM-independent fusion activity. Among the collection of variants, mutations were identified in regions encoding both the receptor-binding (S1) and fusion-inducing (S2) subunits of the spike protein. Each mutation was separately introduced into cDNA encoding the prototype JHM spike, and the set of cDNAs was expressed using vaccinia virus vectors. The variant spikes were similar to that of JHM in their assembly into oligomers, their proteolysis into S1 and S2 cleavage products, their transport to cell surfaces, and their affinity for a soluble form of murine CEACAM. However, these tissue culture-adapted spikes were significantly stabilized as S1-S2 heteromers, and their entirely CEACAM-dependent fusion activity was delayed or reduced relative to prototype JHM spikes. The mutations that we have identified therefore point to regions of the S protein that specifically regulate the membrane fusion reaction. We suggest that cultured cells, unlike certain in vivo environments, select for S proteins with delayed, CEACAM-dependent fusion activities that may increase the likelihood of virus internalization prior to the irreversible uncoating process.


2007 ◽  
Vol 81 (11) ◽  
pp. 5637-5648 ◽  
Author(s):  
Renaud Burrer ◽  
Benjamin W. Neuman ◽  
Joey P. C. Ting ◽  
David A. Stein ◽  
Hong M. Moulton ◽  
...  

ABSTRACT The recent emergence of novel pathogenic human and animal coronaviruses has highlighted the need for antiviral therapies that are effective against a spectrum of these viruses. We have used several strains of murine hepatitis virus (MHV) in cell culture and in vivo in mouse models to investigate the antiviral characteristics of peptide-conjugated antisense phosphorodiamidate morpholino oligomers (P-PMOs). Ten P-PMOs directed against various target sites in the viral genome were tested in cell culture, and one of these (5TERM), which was complementary to the 5′ terminus of the genomic RNA, was effective against six strains of MHV. Further studies were carried out with various arginine-rich peptides conjugated to the 5TERM PMO sequence in order to evaluate efficacy and toxicity and thereby select candidates for in vivo testing. In uninfected mice, prolonged P-PMO treatment did not result in weight loss or detectable histopathologic changes. 5TERM P-PMO treatment reduced viral titers in target organs and protected mice against virus-induced tissue damage. Prophylactic 5TERM P-PMO treatment decreased the amount of weight loss associated with infection under most experimental conditions. Treatment also prolonged survival in two lethal challenge models. In some cases of high-dose viral inoculation followed by delayed treatment, 5TERM P-PMO treatment was not protective and increased morbidity in the treated group, suggesting that P-PMO may cause toxic effects in diseased mice that were not apparent in the uninfected animals. However, the strong antiviral effect observed suggests that with further development, P-PMO may provide an effective therapeutic approach against a broad range of coronavirus infections.


Glia ◽  
1989 ◽  
Vol 2 (2) ◽  
pp. 85-93 ◽  
Author(s):  
M.F. van Berlo ◽  
R. Warringa ◽  
G. Wolswijk ◽  
M. Lopes-Cardozo

2005 ◽  
Vol 79 (24) ◽  
pp. 15064-15073 ◽  
Author(s):  
Lubna Kazi ◽  
Arjen Lissenberg ◽  
Richard Watson ◽  
Raoul J. de Groot ◽  
Susan R. Weiss

ABSTRACT Murine hepatitis virus (MHV) infection provides a model system for the study of hepatitis, acute encephalitis, and chronic demyelinating disease. The spike glycoprotein, S, which mediates receptor binding and membrane fusion, plays a critical role in MHV pathogenesis. However, viral proteins other than S also contribute to pathogenicity. The JHM strain of MHV is highly neurovirulent and expresses a second spike glycoprotein, the hemagglutinin esterase (HE), which is not produced by MHV-A59, a hepatotropic but only mildly neurovirulent strain. To investigate a possible role for HE in MHV-induced neurovirulence, isogenic recombinant MHV-A59 viruses were generated that produced either (i) the wild-type protein, (ii) an enzymatically inactive HE protein, or (iii) no HE at all (A. Lissenberg, M. M. Vrolijk, A. L. W. van Vliet, M. A. Langereis, J. D. F. de Groot-Mijnes, P. J. M. Rottier, and R. J. de Groot, J. Virol. 79:15054-15063, 2005 [accompanying paper]). A second, mirror set of recombinant viruses was constructed in which, in addition, the MHV-A59 S gene had been replaced with that from MHV-JHM. The expression of HE in combination with A59 S did not affect the tropism, pathogenicity, or spread of the virus in vivo. However, in combination with JHM S, the expression of HE, regardless of whether it retained esterase activity or not, resulted in increased viral spread within the central nervous system and in increased neurovirulence. Our findings suggest that the properties of S receptor utilization and/or fusogenicity mainly determine organ and host cell tropism but that HE enhances the efficiency of infection and promotes viral dissemination, at least in some tissues, presumably by serving as a second receptor-binding protein.


1998 ◽  
Vol 72 (9) ◽  
pp. 7084-7090 ◽  
Author(s):  
M. Pope ◽  
P. A. Marsden ◽  
E. Cole ◽  
S. Sloan ◽  
L. S. Fung ◽  
...  

ABSTRACT The strain-specific spectrum of liver disease following murine hepatitis virus type 3 (MHV-3) infection is dependent on inflammatory mediators released by macrophages. Production of nitric oxide (NO) by macrophages has been implicated in resistance to a number of viruses, including ectromelia virus, vaccinia virus, and herpes simplex virus type 1. This study was undertaken to define the role of NO in MHV-3 infection. Gamma interferon-induced production of NO inhibited growth of MHV-3 in a murine macrophage cell line (RAW 264.7). Viral inhibitory activity was reproduced by the NO donorS-nitroso-N-acetyl-dl-penicillamine (SNAP), whereas N-acetyl-dl-pencillamine (NAP), an inactive analog of SNAP, had no effect. Electron microscopy studies confirmed the inhibitory effects of NO on viral replication. Peritoneal macrophages isolated from A/J mice known to be resistant to MHV-3 produced a fivefold-higher level of NO and higher levels of mRNA transcripts of inducible NO synthase in response to gamma interferon than macrophages from susceptible BALB/cJ mice. SNAP inhibited growth of MHV-3 in macrophages from both strains of mice to similar degrees. In vivo inhibition of NO byN-monomethyl-l-arginine resulted in loss of resistance to MHV-3 in A/J mice. These results collectively demonstrate a defect in the production of NO in macrophages from susceptible BALB/cJ mice and define the importance of endogenous NO in resistance to MHV-3 infection in resistant A/J mice.


2021 ◽  
Author(s):  
Lynden S Voth ◽  
Joseph J O'Connor ◽  
Catherine M Kerr ◽  
Ethan Doerger ◽  
Nancy Schwarting ◽  
...  

All coronaviruses (CoVs) contain a macrodomain, also termed Mac1, in non-structural protein 3 (nsp3) which binds and hydrolyzes ADP-ribose covalently attached to proteins. Despite several reports demonstrating that Mac1 is a prominent virulence factor, there is still a limited understanding of its cellular roles during infection. Currently, most of the information regarding the role of CoV Mac1 during infection is based on a single point mutant of a highly conserved asparagine-to-alanine mutation, which is known to largely eliminate Mac1 ADP-ribosylhydrolase activity. To determine if Mac1 ADP-ribose binding separately contributes to CoV replication, we compared the replication of a murine hepatitis virus (MHV) Mac1 mutant predicted to dramatically reduce ADP-ribose binding, D1329A, to the previously mentioned asparagine mutant, N1347A. D1329A and N1347A both replicated poorly in bone-marrow derived macrophages (BMDMs), were inhibited by PARP enzymes, and were highly attenuated in vivo. However, D1329A was significantly more attenuated than N1347A in all cell lines tested that were susceptible to MHV infection. In addition, D1329A retained some ability to block IFN-β transcript accumulation compared to N1347A, indicating that these two mutants impacted distinct Mac1 functions. Mac1 mutants predicted to eliminate both binding and hydrolysis activities were unrecoverable, suggesting that the combined activities of Mac1 may be essential for MHV replication. We conclude that Mac1 has multiple roles in promoting the replication of MHV, and that these results provide further evidence that Mac1 could be a prominent target for anti-CoV therapeutics.


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