Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this ...Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.展开更多
Cell death can be classified into two categories: apoptosis and necrosis. Apoptotic pathway can beeither caspase-dependent or caspase-independent. Caspase-independent cytopathic effect (CPE) has beendescribed. In orde...Cell death can be classified into two categories: apoptosis and necrosis. Apoptotic pathway can beeither caspase-dependent or caspase-independent. Caspase-independent cytopathic effect (CPE) has beendescribed. In order to evaluate the pattern of HeLa cell death induced by Coxsackievirus B3 (CVB3)and whether apoptosis involves caspase activation, we co-cultivated HeLa cells with CVB3 and detectedthe cytopathic changes, the alteration of mRNA and protein expression of caspase-3 gene plus caspase-3activity, as well as analyzing DNA fragmentation before and after caspase-3 activity inhibition. Accordingto the results, we propose that CVB3 may induce apoptosis and necrosis in HeLa cells, the latter appearingmuch earlier. Caspase-3 is activated at the levels of both transcription and translation, and procaspase-3 isproteolytically cleaved, thus leading to the continuous increasing of both caspase-3 precursor protein and itssubunit. However, besides CPE, apoptosis induced by CVB3 is not a direct consequence of the activationof caspase-3, or caspase-3 is not the only effector molecule in apoptotic cell death, for caspase-3 inhibitorcan not decrease DNA fragmentation. Some other biochemical mechanisms may participate in the process,whose role weakens the effect of inhibiting caspase-3 activity.展开更多
Guanylate binding protein-1(GBP-1)is an interferon-induced protein.To observe its antiviral effect against Hepatitis B virus(HBV)and Coxsackie virus B3(CVB3),we constructed an eukaryotic expression vector of human GBP...Guanylate binding protein-1(GBP-1)is an interferon-induced protein.To observe its antiviral effect against Hepatitis B virus(HBV)and Coxsackie virus B3(CVB3),we constructed an eukaryotic expression vector of human GBP-1(hGBP-1).Full-length encoding sequence of hGBP-1 was amplified by long chain RT-PCR and inserted into a pCR2.1 vector,then subcloned into a pCDNA3.1(-)vector.Recombinant hGBP-1 plasmids and pHBV1.3 carrying 1.3-fold genome of HBV were contransfected into HepG2 cells,and inhibition effect of hGBP-1 against HBV replication was observed.Hela cells transfected with recombinant hGBP-1 plasmids were challenged with CVB3,and viral yield in cultures were detected.The results indicated that recombinant eukaryotic expression plasmid of hGBP-1 was constructed successfully and the hGBP-1 gene carried in this plasmid could be efficiently expressed in HepG2 cells and Hela cells.hGBP-1 inhibit CVB3 but not HBV replication in vitro.These results demonstrate that hGBP-1 mediates an antiviral effect against CVB3 but not HBV and perhaps plays an important role in the interferon-mediated antiviral response against CVB3.展开更多
Objective To explore the role of coxsackievirus and adenovirus receptor(CAR)in cardiotoxicity infected by coxsackievirus B3. Methods A toxic cellular model was established in vitro by adding myocarditic coxsackievirus...Objective To explore the role of coxsackievirus and adenovirus receptor(CAR)in cardiotoxicity infected by coxsackievirus B3. Methods A toxic cellular model was established in vitro by adding myocarditic coxsackievirus B3(CVB3m)into the culture of neonatal mouse cardiomyocytes.48 h later, the cardiomyocytes were divided into control, CVB3m, and CAR antibody+CVB3m groups. CVB3m-mediated myocytopathic effect of above three groups was observed after further culturing for 48h. At the same time,the cardiomyocytes’viability of above three groups was assessed by MTT assay. Results The degree of cytopathic effect(CPE)of CAR antibody+CVB3m group was significantly lower than CVB3m group (P<0.01)and there was a significant increase in cell viability in CAR antibody+CVB3m group compared with CVB3m group(P<0.01). No significant difference was found between CAR antibody+CVB3m group and control group. Conclusion CAR antibody possesses a protective effect on CVB3m infected cardiomyoctyes, which indicates that CAR may play an important role in mediating cardiotoxicity infected by CVB3m.展开更多
Viral myocarditis(VMC)is one of the most common acquired heart diseases in children and teenagers.However,its pathogenesis is still unclear,and effective treatments are lacking.This study aimed to investigate the regu...Viral myocarditis(VMC)is one of the most common acquired heart diseases in children and teenagers.However,its pathogenesis is still unclear,and effective treatments are lacking.This study aimed to investigate the regulatory pathway by which exosomes alleviate ferroptosis in cardiomyocytes(CMCs)induced by coxsackievirus B3(CVB3).CVB3 was utilized for inducing the VMC mouse model and cellular model.Cardiac echocardiography,left ventricular ejection fraction(LVEF),and left ventricular fractional shortening(LVFS)were implemented to assess the cardiac function.In CVB3-induced VMC mice,cardiac insufficiency was observed,as well as the altered levels of ferroptosis-related indicators(glutathione) peroxidase 4(GPX4),glutathione(GSH),and malondialdehyde(MDA).However,exosomes derived from human umbilical cord mesenchymal stem cells(hucMSCs-exo)could restore the changes caused by CVB3 stimulation.Let-7a-5p was enriched in hucMSCs-exo,and the inhibitory ffect of hucMSCs-exoa-ie-pmimo on CVB3-induced ferroptosis was higher than that of hucMSCs-exommie N(NC:negative control).Mothers against decapentaplegic homolog 2(SMAD2)increased in the VMC group,while the expression of zinc-finger protein 36(ZFP36)decreased.Let-7a-5p was confirmed to interact with SMAD2 messenger RNA(mRNA),and the SMAD2 protein interacted directly with the ZFP36 protein.Silencing SMAD2 and overexpressing ZFP36 inhibited the expression of ferroptosis-related indicators.Meanwhile,the levels of GPX4,solute carrier family 7,member 11(SLC7A11),and GSH were lower in the SMAD2 overexpression plasmid(oe-SMAD2)+let-7a-5p mimic group than in the oe-NC+let-7a-5p mimic group,while those of MDA,reactive oxygen species(ROS),and Fe^(2+)increased.In conclusion,these data showed that ferroptosis could be regulated by mediating SMAD2 expression.Exo-let-7a-5p derived from hucMSCs could mediate SMAD2 to promote the expression of ZFP36,which further inhibited the ferroptosis of CMCs to alleviate CVB3-induced VMC.展开更多
Coxsackievirus B3(CVB3)is the pathogen causing hand,foot and mouth disease(HFMD),which manifests across a spectrum of clinical severity from mild to severe.However,CVB3-infected mouse models mainly demonstrate viral m...Coxsackievirus B3(CVB3)is the pathogen causing hand,foot and mouth disease(HFMD),which manifests across a spectrum of clinical severity from mild to severe.However,CVB3-infected mouse models mainly demonstrate viral myocarditis and pancreatitis,failing to replicate human HFMD symptoms.Although several enteroviruses have been evaluated in Syrian hamsters and rhesus monkeys,there is no comprehensive data on CVB3.In this study,we have first tested the susceptibility of Syrian hamsters to CVB3 infection via different routes.The results showed that Syrian hamsters were successfully infected with CVB3 by intraperitoneal injection or nasal drip,leading to nasopharyngeal colonization,acute severe pathological injury,and typical HFMD symptoms.Notably,the nasal drip group exhibited a longer viral excretion cycle and more severe pathological damage.In the subsequent study,rhesus monkeys infected with CVB3 through nasal drips also presented signs of HFMD symptoms,viral excretion,serum antibody conversion,viral nucleic acids and antigens,and the specific organ damages,particularly in the heart.Surprisingly,there were no significant differences in myocardial enzyme levels,and the clinical symptoms resembled those often associated with common,mild infections.In summary,the study successfully developed severe Syrian hamsters and mild rhesus monkey models for CVB3-induced HFMD.These models could serve as a basis for understanding the disease pathogenesis,conducting pre-trial prevention and evaluation,and implementing post-exposure intervention.展开更多
基金supported by the China Mega-project for Infectious Disease [2018ZX10102001,2018ZX10711001,2018ZX10734401,and 2018ZX10734404]the SKLID Development Grant [2011SKLID104]
文摘Objective Autophagy is a highly conserved intracellular degradation pathway. Many picornaviruses induce autophagy to benefit viral replication, but an understanding of how autophagy occurs remains incomplete. In this study, we explored whether coxsackievirus B3(CVB3) infection induced autophagy through endoplasmic reticulum(ER) stress. Methods In CVB3-infected HeLa cells, the specific molecules of ER stress and autophagy were detected using Western blotting, reverse transcription polymerase chain reaction(RT-PCR), and confocal microscopy. Then PKR-like ER protein kinase(PERK) inhibitor, inositol-requiring protein-1(IRE1) inhibitor, or activating transcription factor-6(ATF6) inhibitor worked on CVB3-infected cells, their effect on autophagy was assessed by Western blotting for detecting microtubule-associated protein light chain 3(LC3). Results CVB3 infection induced ER stress, and ER stress sensors PERK/eIF2α, IRE1/XBP1, and ATF6 were activated. CVB3 infection increased the accumulation of green fluorescent protein(GFP)-LC3 punctuation and induced the conversion from LC3-Ⅰ to phosphatidylethanolamine-conjugated LC3-1(LC3-Ⅱ). CVB3 infection still decreased the expression of mammalian target of rapamycin(mTOR) and p-mTOR. Inhibition of PERK, IRE1, or ATF6 significantly decreased the ratio of LC3-Ⅱ to LC3-Ⅰ in CVB3-infected HeLa cells. Conclusion CVB3 infection induced autophagy through ER stress in HeL a cells, and PERK, IRE1, and ATF6 a pathways participated in the regulation of autophagy. Our data suggested that ER stress may inhibit mTOR signaling pathway to induce autophagy during CVB3 infection.
文摘Cell death can be classified into two categories: apoptosis and necrosis. Apoptotic pathway can beeither caspase-dependent or caspase-independent. Caspase-independent cytopathic effect (CPE) has beendescribed. In order to evaluate the pattern of HeLa cell death induced by Coxsackievirus B3 (CVB3)and whether apoptosis involves caspase activation, we co-cultivated HeLa cells with CVB3 and detectedthe cytopathic changes, the alteration of mRNA and protein expression of caspase-3 gene plus caspase-3activity, as well as analyzing DNA fragmentation before and after caspase-3 activity inhibition. Accordingto the results, we propose that CVB3 may induce apoptosis and necrosis in HeLa cells, the latter appearingmuch earlier. Caspase-3 is activated at the levels of both transcription and translation, and procaspase-3 isproteolytically cleaved, thus leading to the continuous increasing of both caspase-3 precursor protein and itssubunit. However, besides CPE, apoptosis induced by CVB3 is not a direct consequence of the activationof caspase-3, or caspase-3 is not the only effector molecule in apoptotic cell death, for caspase-3 inhibitorcan not decrease DNA fragmentation. Some other biochemical mechanisms may participate in the process,whose role weakens the effect of inhibiting caspase-3 activity.
基金National Natural Science Foundation (No.30271170,No.30170889).
文摘Guanylate binding protein-1(GBP-1)is an interferon-induced protein.To observe its antiviral effect against Hepatitis B virus(HBV)and Coxsackie virus B3(CVB3),we constructed an eukaryotic expression vector of human GBP-1(hGBP-1).Full-length encoding sequence of hGBP-1 was amplified by long chain RT-PCR and inserted into a pCR2.1 vector,then subcloned into a pCDNA3.1(-)vector.Recombinant hGBP-1 plasmids and pHBV1.3 carrying 1.3-fold genome of HBV were contransfected into HepG2 cells,and inhibition effect of hGBP-1 against HBV replication was observed.Hela cells transfected with recombinant hGBP-1 plasmids were challenged with CVB3,and viral yield in cultures were detected.The results indicated that recombinant eukaryotic expression plasmid of hGBP-1 was constructed successfully and the hGBP-1 gene carried in this plasmid could be efficiently expressed in HepG2 cells and Hela cells.hGBP-1 inhibit CVB3 but not HBV replication in vitro.These results demonstrate that hGBP-1 mediates an antiviral effect against CVB3 but not HBV and perhaps plays an important role in the interferon-mediated antiviral response against CVB3.
文摘Objective To explore the role of coxsackievirus and adenovirus receptor(CAR)in cardiotoxicity infected by coxsackievirus B3. Methods A toxic cellular model was established in vitro by adding myocarditic coxsackievirus B3(CVB3m)into the culture of neonatal mouse cardiomyocytes.48 h later, the cardiomyocytes were divided into control, CVB3m, and CAR antibody+CVB3m groups. CVB3m-mediated myocytopathic effect of above three groups was observed after further culturing for 48h. At the same time,the cardiomyocytes’viability of above three groups was assessed by MTT assay. Results The degree of cytopathic effect(CPE)of CAR antibody+CVB3m group was significantly lower than CVB3m group (P<0.01)and there was a significant increase in cell viability in CAR antibody+CVB3m group compared with CVB3m group(P<0.01). No significant difference was found between CAR antibody+CVB3m group and control group. Conclusion CAR antibody possesses a protective effect on CVB3m infected cardiomyoctyes, which indicates that CAR may play an important role in mediating cardiotoxicity infected by CVB3m.
基金supported by the China Postdoctoral Science Foundation(No.2022M712252)the Natural Science Foundation of Sichuan Province,China(No.2023NSFSC1634).
文摘Viral myocarditis(VMC)is one of the most common acquired heart diseases in children and teenagers.However,its pathogenesis is still unclear,and effective treatments are lacking.This study aimed to investigate the regulatory pathway by which exosomes alleviate ferroptosis in cardiomyocytes(CMCs)induced by coxsackievirus B3(CVB3).CVB3 was utilized for inducing the VMC mouse model and cellular model.Cardiac echocardiography,left ventricular ejection fraction(LVEF),and left ventricular fractional shortening(LVFS)were implemented to assess the cardiac function.In CVB3-induced VMC mice,cardiac insufficiency was observed,as well as the altered levels of ferroptosis-related indicators(glutathione) peroxidase 4(GPX4),glutathione(GSH),and malondialdehyde(MDA).However,exosomes derived from human umbilical cord mesenchymal stem cells(hucMSCs-exo)could restore the changes caused by CVB3 stimulation.Let-7a-5p was enriched in hucMSCs-exo,and the inhibitory ffect of hucMSCs-exoa-ie-pmimo on CVB3-induced ferroptosis was higher than that of hucMSCs-exommie N(NC:negative control).Mothers against decapentaplegic homolog 2(SMAD2)increased in the VMC group,while the expression of zinc-finger protein 36(ZFP36)decreased.Let-7a-5p was confirmed to interact with SMAD2 messenger RNA(mRNA),and the SMAD2 protein interacted directly with the ZFP36 protein.Silencing SMAD2 and overexpressing ZFP36 inhibited the expression of ferroptosis-related indicators.Meanwhile,the levels of GPX4,solute carrier family 7,member 11(SLC7A11),and GSH were lower in the SMAD2 overexpression plasmid(oe-SMAD2)+let-7a-5p mimic group than in the oe-NC+let-7a-5p mimic group,while those of MDA,reactive oxygen species(ROS),and Fe^(2+)increased.In conclusion,these data showed that ferroptosis could be regulated by mediating SMAD2 expression.Exo-let-7a-5p derived from hucMSCs could mediate SMAD2 to promote the expression of ZFP36,which further inhibited the ferroptosis of CMCs to alleviate CVB3-induced VMC.
基金supported by several key projects,the Medical and Health Science and Technology Innovation Project of the Chinese Academy of Medical Sciences(CIFMS,2016-I2M-2-001)the National Resource Center for Non-Human Primates,Major Science and Technology Special Projects in Yunnan Province,Kunming Science and Technology Innovation and Service Capacity Enhancement Program Key Projects(2016-2-R-07674)+3 种基金the CAMS Innovation Fund for Medical Sciences(CIFMS,2018-I2M-3-002 and 2021-I2M-1-024)the National Key R&D Project of China(2021YFF0702804)Peking Union Medical College-Central University Basic Scientific Research Business Fee(Project number.:3332023079)Yunnan Province Applied Basic Research Special Project-General Project(project number:202401CF070048,202301AT070367).
文摘Coxsackievirus B3(CVB3)is the pathogen causing hand,foot and mouth disease(HFMD),which manifests across a spectrum of clinical severity from mild to severe.However,CVB3-infected mouse models mainly demonstrate viral myocarditis and pancreatitis,failing to replicate human HFMD symptoms.Although several enteroviruses have been evaluated in Syrian hamsters and rhesus monkeys,there is no comprehensive data on CVB3.In this study,we have first tested the susceptibility of Syrian hamsters to CVB3 infection via different routes.The results showed that Syrian hamsters were successfully infected with CVB3 by intraperitoneal injection or nasal drip,leading to nasopharyngeal colonization,acute severe pathological injury,and typical HFMD symptoms.Notably,the nasal drip group exhibited a longer viral excretion cycle and more severe pathological damage.In the subsequent study,rhesus monkeys infected with CVB3 through nasal drips also presented signs of HFMD symptoms,viral excretion,serum antibody conversion,viral nucleic acids and antigens,and the specific organ damages,particularly in the heart.Surprisingly,there were no significant differences in myocardial enzyme levels,and the clinical symptoms resembled those often associated with common,mild infections.In summary,the study successfully developed severe Syrian hamsters and mild rhesus monkey models for CVB3-induced HFMD.These models could serve as a basis for understanding the disease pathogenesis,conducting pre-trial prevention and evaluation,and implementing post-exposure intervention.
