RESUMEN

Rationale: Parkin (an E3 ubiquitin protein ligase) is an important regulator of mitophagy. However, the role of Parkin in viral myocarditis (VMC) remains unclear. Methods: Coxsackievirus B3 (CVB3) infection was induced in mice to create VMC. Cardiac function and inflammatory response were evaluated by echocardiography, histological assessment, and molecular analyses. AAV9 (adeno-associated virus 9), transmission electron microscopy (TEM) and western blotting were used to investigate the mechanisms by which Parkin regulates mitophagy and cardiac inflammation. Results: Our data indicated that Parkin- and BNIP3 (BCL2 interacting protein 3 like)-mediated mitophagy was activated in VMC mice and neonatal rat cardiac myocytes (NRCMs) infected with CVB3, which blocked autophagic flux by inhibiting autophagosome-lysosome fusion. Parkin silencing aggravated mortality and accelerated the development of cardiac dysfunction in CVB3-treated mice. While silencing of Parkin did not significantly increase inflammatory response through activating NF-κB pathway and production of inflammatory cytokines post-VMC, the mitophagy activity were reduced, which stimulated the accumulation of damaged mitochondria. Moreover, Parkin silencing exacerbated VMC-induced apoptosis. We consistently found that Parkin knockdown disrupted mitophagy activity and inflammatory response in NRCMs. Conclusion: This study elucidated the important role of Parkin in maintaining cardiac function and inflammatory response by regulating mitophagy activity and the NF-κB pathway during acute VMC. Although the functional impact of mitophagy remains unclear, our findings suggest that Parkin silencing may accelerate VMC development.

Asunto(s)

Infecciones por Coxsackievirus , Mitofagia , Miocarditis , Miocitos Cardíacos , Ubiquitina-Proteína Ligasas , Animales , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Miocarditis/virología , Miocarditis/metabolismo , Ratones , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/virología , Infecciones por Coxsackievirus/metabolismo , Infecciones por Coxsackievirus/virología , Masculino , Ratas , Enterovirus Humano B/fisiología , Apoptosis , Modelos Animales de Enfermedad , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas Mitocondriales/metabolismo , Proteínas Mitocondriales/genética , FN-kappa B/metabolismo , Ratones Endogámicos BALB C

RESUMEN

Myocarditis is an inflammatory disease that may lead to dilated cardiomyopathy. Viral infection of the myocardium triggers immune responses, which involve, among others, macrophage infiltration, oxidative stress, expression of pro-inflammatory cytokines, and microRNAs (miRNAs). The cardioprotective role of estrogen in myocarditis is well documented; however, sex differences in the miRNA expression in chronic myocarditis are still poorly understood, and studying them further was the aim of the present study. Male and female ABY/SnJ mice were infected with CVB3. Twenty-eight days later, cardiac tissue from both infected and control mice was used for real-time PCR and Western blot analysis. NFκB, IL-6, iNOS, TNF-α, IL-1ß, MCP-1, c-fos, and osteopontin (OPN) were used to examine the inflammatory state in the heart. Furthermore, the expression of several inflammation- and remodeling-related miRNAs was analyzed. NFκB, IL-6, TNF-α, IL-1ß, iNOS, and MCP-1 were significantly upregulated in male mice with CVB3-induced chronic myocarditis, whereas OPN mRNA expression was increased only in females. Further analysis revealed downregulation of some anti-inflammatory miRNA in male hearts (let7a), with upregulation in female hearts (let7b). In addition, dysregulation of remodeling-related miRNAs (miR27b and mir199a) in a sex-dependent manner was observed. Taken together, the results of the present study suggest a sex-specific expression of pro-inflammatory markers as well as inflammation- and remodeling-related miRNAs, with a higher pro-inflammatory response in male CVB3 myocarditis mice.

Asunto(s)

Infecciones por Coxsackievirus , Modelos Animales de Enfermedad , MicroARNs , Miocarditis , Animales , Miocarditis/metabolismo , Miocarditis/virología , Miocarditis/genética , MicroARNs/genética , MicroARNs/metabolismo , Femenino , Masculino , Ratones , Infecciones por Coxsackievirus/metabolismo , Infecciones por Coxsackievirus/genética , Infecciones por Coxsackievirus/virología , Enterovirus Humano B , Biomarcadores/metabolismo , Caracteres Sexuales , Citocinas/metabolismo , Citocinas/genética , Miocardio/metabolismo , Miocardio/patología , Inflamación/genética , Inflamación/metabolismo , Factores Sexuales , Regulación de la Expresión Génica

RESUMEN

Acute pancreatitis (AP) is an inflammatory disease initiated by the death of exocrine acinar cells, but its pathogenesis remains unclear. Signal transducer and activator of transcription 3 (STAT3) is a multifunctional factor that regulates immunity and the inflammatory response. The protective role of STAT3 is reported in Coxsackievirus B3 (CVB3)-induced cardiac fibrosis, yet the exact role of STAT3 in modulating viral-induced STAT1 activation and type I interferon (IFN)-stimulated gene (ISG) transcription in the pancreas remains unclarified. In this study, we tested whether STAT3 regulated viral-induced STAT1 translocation. We found that CVB3, particularly capsid VP1 protein, markedly upregulated the phosphorylation and nuclear import of STAT3 (p-STAT3) while it significantly impeded the nuclear translocation of p-STAT1 in the pancreases and hearts of mice on day 3 postinfection (p.i.). Immunoblotting and an immunofluorescent assay demonstrated the increased expression and nuclear translocation of p-STAT3 but a blunted p-STAT1 nuclear translocation in CVB3-infected acinar 266-6 cells. STAT3 shRNA knockdown or STAT3 inhibitors reduced viral replication via the rescue of STAT1 nuclear translocation and increasing the ISRE activity and ISG transcription in vitro. The knockdown of STAT1 blocked the antiviral effect of the STAT3 inhibitor. STAT3 inhibits STAT1 activation by virally inducing a potent inhibitor of IFN signaling, the suppressor of cytokine signaling-3 ((SOCS)-3). Sustained pSTAT1 and the elevated expression of ISGs were induced in SOCS3 knockdown cells. The in vivo administration of HJC0152, a pharmaceutical STAT3 inhibitor, mitigated the viral-induced AP and myocarditis pathology via increasing the IFNß as well as ISG expression on day 3 p.i. and reducing the viral load in multi-organs. These findings define STAT3 as a negative regulator of the type I IFN response via impeding the nuclear STAT1 translocation that otherwise triggers ISG induction in infected pancreases and hearts. Our findings identify STAT3 as an antagonizing factor of the IFN-STAT1 signaling pathway and provide a potential therapeutic target for viral-induced AP and myocarditis.

Asunto(s)

Enterovirus Humano B , Miocarditis , Pancreatitis , Factor de Transcripción STAT1 , Factor de Transcripción STAT3 , Replicación Viral , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT1/genética , Miocarditis/virología , Miocarditis/metabolismo , Miocarditis/patología , Miocarditis/genética , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Animales , Pancreatitis/metabolismo , Pancreatitis/virología , Pancreatitis/patología , Pancreatitis/genética , Enterovirus Humano B/fisiología , Ratones , Humanos , Infecciones por Coxsackievirus/metabolismo , Infecciones por Coxsackievirus/virología , Infecciones por Coxsackievirus/patología , Infecciones por Coxsackievirus/genética , Núcleo Celular/metabolismo , Masculino , Transporte Activo de Núcleo Celular , Regulación de la Expresión Génica , Enfermedad Aguda , Línea Celular , Transducción de Señal

RESUMEN

OBJECTIVE: The main pathological change of myocarditis is an inflammatory injury of cardiomyocytes. Long noncoding RNAs (lncRNAs) are closely related to inflammation, and our previous study showed that differential expression of lncRNAs is associated with myocarditis. This study aimed to investigate the impact of lncRNAs on the onset of myocarditis. METHODS: RNA expression was measured by quantitative reverse-transcription polymerase chain reaction (RT-qPCR). Lipopolysaccharide (LPS) was used to induce inflammation in human cardiomyocytes (HCMs). The expression of inflammatory cytokines and myocardial injury markers was detected by enzyme-linked immunosorbent assay (ELISA) and RT-qPCR. Cell viability and apoptosis were measured by the cell counting kit-8 assay and flow cytometry. The binding force between lncRNA NONHSAT122636.2 and microRNA miRNA-2110 was detected using the dual-luciferase assay. RESULTS: NONHSAT122636.2 was dynamically expressed in patients with myocarditis and negatively correlated with inflammation severity. The overexpression of NONHSAT122636.2 improved inflammatory injury in LPS-stimulated HCMs. The study observed that there was a weak binding force between NONHSAT122636.2 and miR-2110. CONCLUSION: NONHSAT122636.2 attenuates myocardial inflammation and apoptosis in myocarditis. Additionally, its expression decreases in the peripheral blood of children suffering from myocarditis and in patients who are diagnosed for the first time showing higher diagnostic sensitivity and specificity. This decrease is negatively correlated with the degree of inflammation. Overall, the study suggests that NONHSAT122636.2 can be exploited as a potential diagnostic biomarker for pediatric myocarditis.

Asunto(s)

Apoptosis , MicroARNs , Miocarditis , Miocitos Cardíacos , ARN Largo no Codificante , Miocarditis/genética , Miocarditis/patología , Miocarditis/metabolismo , ARN Largo no Codificante/genética , Humanos , Apoptosis/efectos de los fármacos , MicroARNs/genética , MicroARNs/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Masculino , Femenino , Lipopolisacáridos/farmacología , Niño , Inflamación/genética , Inflamación/patología , Preescolar , Citocinas/metabolismo , Citocinas/genética

RESUMEN

Coxsackievirus group B3 (CVB3) belongs to the genus Enteroviruses of the family Picornaviridae and is the main pathogen underlying viral myocarditis (VMC). No specific therapeutic is available for this condition. Argininosuccinate synthase 1 (ASS1) is a key enzyme in the urea cycle that converts citrulline and aspartic acid to argininosuccinate. Here, we found that CVB3 and its capsid protein VP2 inhibit the autophagic degradation of ASS1 and that CVB3 consumes citrulline to upregulate ASS1, triggers urea cycle metabolic reprogramming, and then activates macrophages to develop pro-inflammatory polarization, thereby promoting the occurrence and development of VMC. Conversely, citrulline supplementation to prevent depletion can downregulate ASS1, rescue macrophage polarization, and alleviate the pathogenicity of VMC. These findings provide a new perspective on the occurrence and development of VMC, revealing ASS1 as a potential new target for treating this disease. IMPORTANCE: Viral myocarditis (VMC) is a common and potentially life-threatening myocardial inflammatory disease, most commonly caused by CVB3 infection. So far, the pathogenesis of VMC caused by CVB3 is mainly focused on two aspects: one is the direct myocardial injury caused by a large number of viral replication in the early stage of infection, and the other is the local immune cell infiltration and inflammatory damage of the myocardium in the adaptive immune response stage. There are few studies on the early innate immunity of CVB3 infection in myocardial tissue, but the appearance of macrophages in the early stage of CVB3 infection suggests that they can play a regulatory role as early innate immune response cells in myocardial tissue. Here, we discovered a possible new mechanism of VMC caused by CVB3, revealed new drug targets for anti-CVB3, and discovered the therapeutic potential of citrulline for VMC.

Asunto(s)

Argininosuccinato Sintasa , Infecciones por Coxsackievirus , Enterovirus Humano B , Macrófagos , Miocarditis , Miocarditis/virología , Miocarditis/metabolismo , Miocarditis/inmunología , Miocarditis/patología , Enterovirus Humano B/fisiología , Animales , Macrófagos/virología , Macrófagos/metabolismo , Macrófagos/inmunología , Ratones , Infecciones por Coxsackievirus/virología , Infecciones por Coxsackievirus/inmunología , Infecciones por Coxsackievirus/metabolismo , Argininosuccinato Sintasa/metabolismo , Humanos , Masculino , Inflamación/metabolismo , Miocardio/metabolismo , Miocardio/patología , Miocardio/inmunología , Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/inmunología , Reprogramación Metabólica

RESUMEN

Viral myocarditis is characterized by infiltration of mononuclear cells essential for virus elimination. GPR15 has been identified as a homing receptor for regulatory T cells in inflammatory intestine diseases, but its role in inflammatory heart diseases is still elusive. Here we show that GPR15 deficiency impairs coxsackievirus B3 elimination, leading to adverse cardiac remodeling and dysfunction. Delayed recruitment of regulatory T cells in GPR15-deficient mice was accompanied by prolonged persistence of cytotoxic and regulatory T cells. In addition, RNA sequencing revealed prolonged inflammatory response and altered chemotaxis in knockout mice. In line, we identified GPR15 and its ligand GPR15L as an important chemokine receptor-ligand pair for the recruitment of regulatory and cytotoxic T cells. In summary, the insufficient virus elimination might be caused by a delayed recruitment of T cells as well as delayed interferon-γ expression, resulting in a prolonged inflammatory response and an adverse outcome in GPR15-deficient mice.

Asunto(s)

Infecciones por Coxsackievirus , Modelos Animales de Enfermedad , Enterovirus Humano B , Ratones Noqueados , Miocarditis , Receptores Acoplados a Proteínas G , Animales , Miocarditis/inmunología , Miocarditis/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/deficiencia , Receptores Acoplados a Proteínas G/inmunología , Infecciones por Coxsackievirus/inmunología , Infecciones por Coxsackievirus/genética , Enterovirus Humano B/inmunología , Ratones Endogámicos C57BL , Linfocitos T Reguladores/inmunología , Enfermedad Aguda , Interferón gamma/metabolismo , Ratones , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismo , Masculino , Quimiotaxis de Leucocito/genética , Quimiotaxis de Leucocito/inmunología , Miocardio/metabolismo , Miocardio/inmunología , Miocardio/patología , Transducción de Señal

RESUMEN

Immune checkpoint inhibitor (ICI)-induced myocarditis involves intensive immune/inflammation activation; however, its molecular basis is unclear. Here, we show that gasdermin-E (GSDME), a gasdermin family member, drives ICI-induced myocarditis. Pyroptosis mediated by GSDME, but not the canonical GSDMD, is activated in myocardial tissue of mice and cancer patients with ICI-induced myocarditis. Deficiency of GSDME in male mice alleviates ICI-induced cardiac infiltration of T cells, macrophages, and monocytes, as well as mitochondrial damage and inflammation. Restoration of GSDME expression specifically in cardiomyocytes, rather than myeloid cells, in GSDME-deficient mice reproduces ICI-induced myocarditis. Mechanistically, quantitative proteomics reveal that GSDME-dependent pyroptosis promotes cell death and mitochondrial DNA release, which in turn activates cGAS-STING signaling, triggering a robust interferon response and myocardial immune/inflammation activation. Pharmacological blockade of GSDME attenuates ICI-induced myocarditis and improves long-term survival in mice. Our findings may advance the understanding of ICI-induced myocarditis and suggest that targeting the GSDME-cGAS-STING-interferon axis may help prevent and manage ICI-associated myocarditis.

Asunto(s)

Inhibidores de Puntos de Control Inmunológico , Proteínas de la Membrana , Miocarditis , Nucleotidiltransferasas , Piroptosis , Animales , Miocarditis/inmunología , Miocarditis/patología , Miocarditis/inducido químicamente , Miocarditis/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Ratones , Masculino , Humanos , Nucleotidiltransferasas/metabolismo , Nucleotidiltransferasas/genética , Transducción de Señal , Ratones Endogámicos C57BL , Ratones Noqueados , ADN Mitocondrial/metabolismo , ADN Mitocondrial/genética , Femenino , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Miocitos Cardíacos/efectos de los fármacos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas de Unión a Fosfato/metabolismo , Proteínas de Unión a Fosfato/genética , Gasderminas

RESUMEN

Myocarditis is an inflammatory heart disease that leads to loss of cardiomyocytes and frequently precipitates fibrotic remodeling of the myocardium, culminating in heart failure. However, the molecular mechanisms underlying immune cell control and maintenance of tissue integrity in the inflamed cardiac microenvironment remain elusive. In this study, we found that bone morphogenic protein-4 (BMP4) gradients maintain cardiac tissue homeostasis by single-cell transcriptomics analyses of inflamed murine and human myocardial tissues. Cardiac BMP pathway dysregulation was reflected by reduced BMP4 serum concentration in patients with myocarditis. Restoration of BMP signaling by antibody-mediated neutralization of the BMP inhibitors gremlin-1 and gremlin-2 ameliorated T cell-induced myocardial inflammation in mice. Moreover, progression to inflammatory cardiomyopathy was blocked through the reduction of fibrotic remodeling and preservation of cardiomyocyte integrity. These results unveil the BMP4-gremlin axis as a druggable pathway for the treatment of myocardial inflammation, limiting the severe sequelae of cardiac fibrosis and heart failure.

Asunto(s)

Enfermedades Autoinmunes , Proteína Morfogenética Ósea 4 , Modelos Animales de Enfermedad , Fibrosis , Miocarditis , Miocarditis/metabolismo , Miocarditis/patología , Miocarditis/inmunología , Animales , Fibrosis/patología , Fibrosis/metabolismo , Proteína Morfogenética Ósea 4/metabolismo , Proteína Morfogenética Ósea 4/genética , Humanos , Enfermedades Autoinmunes/patología , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/inmunología , Masculino , Transducción de Señal , Ratones , Microambiente Celular , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Femenino , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratones Endogámicos C57BL , Miocardio/metabolismo , Miocardio/patología , Miocardio/inmunología

Asunto(s)

Proteína Morfogenética Ósea 4 , Fibrosis , Proteína Morfogenética Ósea 4/metabolismo , Proteína Morfogenética Ósea 4/genética , Animales , Fibrosis/metabolismo , Fibrosis/patología , Humanos , Miocardio/patología , Miocardio/metabolismo , Miocarditis/patología , Miocarditis/metabolismo , Miocarditis/inmunología , Ratones , Transducción de Señal

RESUMEN

BACKGROUND: Prolonged exposure to interleukin-17A (IL-17A) can induce autoimmune myocarditis, and MLN4924, an inhibitor of NEDD8 activating enzyme (NAE), has been reported to effectively suppress various inflammatory reactions. However, the effects of MLN4924 in IL-17A-mediated inflammation associated with autoimmune myocarditis remain uncertain. METHODS: An experimental autoimmune myocarditis (EAM) model was established and treated with MLN4924. The inflammation degree of heart tissues was assessed histopathologically. The expression levels of inflammatory cytokines and chemokines were measured using ELISA and RT-qPCR, respectively. Additionally, the interaction of biomacromolecules was detected through co-immunoprecipitation (Co-IP) and RNA immunoprecipitation (RIP). RESULTS: MLN4924 could attenuate IL-17A-induced inflammation. In the in vivo studies, MLN4924 treatment improved inflammatory responses, diminished immune cell infiltration and tissue fibrosis, and reduced the secretion of various inflammatory cytokines in serum, including IL-1ß, IL-6, TNF-α, and MCP-1. In vitro experiments further corroborated these findings, showing that MLN4924 treatment reduced the secretion and transcription of pro-inflammatory factors, particularly MCP-1. Mechanistically, we confirmed that MLN4924 promoted Act1 ubiquitination degradation and disrupted Act1's interaction with IL-17R, thereby impeding the formation of the IL-17R/Act1/TRAF6 complex and subsequent activation of TAK1, c-Jun, and p65. Moreover, MLN4924 interfered with Act1's binding to mRNA, resulting in mRNA instability. CONCLUSIONS: In conclusion, MLN4924 effectively alleviated inflammatory symptoms in EAM by disrupting the interaction between IL and 17R and Act1, thereby reducing Act1-mediated mRNA stability and resulting in decreased expression of pro-inflammatory factors.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Enfermedades Autoinmunes , Ciclopentanos , Citocinas , Miocarditis , Pirimidinas , Estabilidad del ARN , Animales , Miocarditis/tratamiento farmacológico , Miocarditis/inmunología , Miocarditis/metabolismo , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Enfermedades Autoinmunes/tratamiento farmacológico , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Ciclopentanos/farmacología , Ciclopentanos/uso terapéutico , Ratones , Estabilidad del ARN/efectos de los fármacos , Masculino , Citocinas/metabolismo , Interleucina-17/metabolismo , Modelos Animales de Enfermedad , Humanos , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , ARN Mensajero/metabolismo , Ratones Endogámicos BALB C

RESUMEN

This study aims to elucidate the role of TIP30 (30 KDa HIV-1 TAT-Interacting Protein) in the progression of coxsackievirus B3 (CVB3)-induced viral myocarditis. TIP30 knockout and wildtype mice were intraperitoneally infected with CVB3 and evaluated at day 7 post-infection. HeLa cells were transfected with TIP30 lentiviral particles and subsequently infected with CVB3 to evaluate viral replication, cellular pathogenesis, and mechanistic target of rapamycin complex 1 (mTORC1) signaling. Deletion of the TIP30 gene heightened heart virus titers and mortality rates in mice with CVB3-induced myocarditis, exacerbating cardiac damage and fibrosis, and elevating pro-inflammatory factors level. In vitro experiments demonstrated the modulation of mTORC1 signaling by TIP30 during CVB3 infection in HeLa cells. TIP30 overexpression mitigated CVB3-induced cellular pathogenesis and VP1 expression, with rapamycin, an mTOR1 inhibitor, reversing these effects. These findings suggest TIP30 plays a critical protective role against CVB3-induced myocarditis by regulating mTORC1 signaling.

Asunto(s)

Infecciones por Coxsackievirus , Enterovirus Humano B , Diana Mecanicista del Complejo 1 de la Rapamicina , Ratones Noqueados , Miocarditis , Transducción de Señal , Animales , Humanos , Masculino , Ratones , Infecciones por Coxsackievirus/virología , Infecciones por Coxsackievirus/metabolismo , Modelos Animales de Enfermedad , Enterovirus Humano B/fisiología , Células HeLa , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Miocarditis/virología , Miocarditis/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Replicación Viral

RESUMEN

Myocarditis (MC) is a myocardial inflammatory disease that threats human life. Pitavastatin (Pit) is a unique lipophilic statin with potent effects on lowering plasma total cholesterol and triacylglycerols. It has been reported to have pleiotropic effects, such as reducing inflammation and oxidative stress. However, the regulatory mechanism of Pit in MC remains a mystery. Two MC models were established in vitro (lipopolysaccharides-(LPS)-stimulated H9c2 cells) and in vivo (intraperitoneal injection of LPS in mice). The levels of microRNA-106b-5p (miR-106b-5p) and mitogen-activated protein kinase kinase kinase 2 (MAP3K2) were detected. ELISA was used to analyze in vivo cell inflammatory factors and myocardial injury markers, kits were used to detect the expression of antioxidant enzymes, cell counting kit-8 (CCK-8) was used to detect cell proliferation, and flow cytometry was used to detect apoptosis. Hematoxylin and eosin (HE) staining was used to detect the pathological changes of myocardial tissue in mice, and TUNEL staining was used to detect in vivo tissue cell apoptosis. The regulatory mechanism of Pit on miR-106b-5p/MAP3K2 was verified by a series of functional rescue experiments. The results demonstrated that in LPS-induced H9c2 cells, antioxidant enzymes decreased and pro-inflammatory factors and cardiac injury markers increased (p<0.05). However, these phenomenons were attenuated by Pit pretreatment. LPS decreased miR-106b-5p and elevated MAP3K2 in H9c2 cells, while Pit could recover their expression patterns (p<0.05). MAP3K2 was confirmed as a target gene of miR-106b-5p. Upregulating miR-106b-5p or downregulating MAP3K2 could further promote the protective effect of Pit, and vice versa (p<0.05). In addition, in the LPS-induced MC mouse model, histological examination showed that Pit significantly improved the myocardial tissue damage in MC mice, while downregulating miR-106b-5p or upregulating MAP3K2 could suppress the ameliorative effect of Pit (p<0.05). In conclusion, our study demonstrated that Pit ameliorates myocardial injury by suppressing myocardial inflammation and oxidative stress by modulating the miR-106b-5p/MAP3K2 axis.

Asunto(s)

Lipopolisacáridos , MicroARNs , Miocarditis , Estrés Oxidativo , Animales , MicroARNs/metabolismo , MicroARNs/genética , Estrés Oxidativo/efectos de los fármacos , Miocarditis/tratamiento farmacológico , Miocarditis/metabolismo , Miocarditis/patología , Masculino , Ratones , Línea Celular , Lipopolisacáridos/toxicidad , Quinolinas/farmacología , MAP Quinasa Quinasa Quinasa 2/metabolismo , Ratas , Apoptosis/efectos de los fármacos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Miocardio/patología , Miocardio/metabolismo , Ratones Endogámicos BALB C , Inflamación/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología

RESUMEN

Long non-coding RNAs (lncRNAs) have been implicated in dilated cardiomyopathy (DCM). However, the biological functions and regulatory mechanisms of lncRNAs in DCM remain elusive. Using a mouse model of experimental autoimmune myocarditis (EAM) to mimic DCM, we successfully constructed a dynamic lncRNA expression library for EAM by lncRNA microarray and found that the expression of a macrophage-enriched lncRNA, MAAMT, was significantly increased in the myocardial tissue of mice at the acute stage of EAM. Functionally, MAAMT knockdown alleviated the recruitment and proinflammatory activation of macrophages in the heart, spleen, and peripheral blood of mice at the acute stage of EAM, reduced myocardial inflammation and injury, and eventually reversed ventricular remodelling and improved cardiac function in mice at the chronic stage of EAM. Mechanistically, we identified serine/arginine-rich splicing factor 1 (SRSF1) as an MAAMT-interacting protein in macrophages using RNA pull-down assays coupled with mass spectrometry. MAAMT knockdown attenuated the ubiquitination-mediated degradation of SRSF1, increased the protein expression of SRSF1, and restrained the activation of the NF-κB pathway in macrophages, thereby inhibiting the proinflammatory activation of macrophages. Collectively, our results demonstrate that MAAMT is a key proinflammatory regulator of myocarditis that promotes macrophage activation through the SRSF1-NF-κB axis, providing a new insight into early effective treatment strategies for DCM.

Asunto(s)

Enfermedades Autoinmunes , Macrófagos , Miocarditis , FN-kappa B , ARN Largo no Codificante , Factores de Empalme Serina-Arginina , Transducción de Señal , Animales , Miocarditis/metabolismo , Miocarditis/inmunología , Miocarditis/genética , Miocarditis/patología , ARN Largo no Codificante/genética , Factores de Empalme Serina-Arginina/metabolismo , Factores de Empalme Serina-Arginina/genética , Ratones , FN-kappa B/metabolismo , Macrófagos/metabolismo , Macrófagos/inmunología , Enfermedades Autoinmunes/genética , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/inmunología , Masculino , Modelos Animales de Enfermedad , Activación de Macrófagos , Inflamación/genética , Inflamación/metabolismo

RESUMEN

Immune checkpoint therapies can drive antitumor responses and benefit patients but can also induce life-threatening immune-related adverse events such as myocarditis and myositis. These immune-related adverse events are rare but carry substantial morbidity and mortality. In this issue, Siddiqui and colleagues use single-cell RNA and T-cell receptor sequencing to identify novel cellular subsets and propose various mechanisms that could contribute to the pathogenesis of immune checkpoint inhibitor-associated myocarditis and myositis. These new insights should help move the field toward the development of improved treatment and prevention options, ultimately improving patient outcomes. See related article by Siddiqui et al., p. 964 (1).

Asunto(s)

Inhibidores de Puntos de Control Inmunológico , Miocarditis , Miositis , Miocarditis/genética , Miocarditis/etiología , Miocarditis/metabolismo , Humanos , Miositis/genética , Miositis/inmunología , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Animales

RESUMEN

Myocardial somatostatin PET uptake is observed not only in most patients with acute myocarditis (AM) but also in some oncology patients referred for routine somatostatin PET. This raises concerns about the specificity of somatostatin PET for detecting myocarditis. The current study aims to identify factors associated with the detection of myocardial uptake on somatostatin PET scans recorded for oncology indications and differential PET criteria that characterize myocardial uptake in AM patients. Methods: We analyzed factors associated with the detection of myocardial [68Ga]Ga-DOTATOC uptake in 508 [68Ga]Ga-DOTATOC PET scans from 178 patients, performed for confirmed or suspected oncologic disease (Onc-PET) and PET criteria that could differentiate myocardial [68Ga]Ga-DOTATOC uptake in 31 patients with MRI-ascertained AM (AM-PET) from that in the Onc-PET group. Results: Significant myocardial uptake was detected in 137 (26.9%) Onc-PET scans and was independently associated with somatostatin analog treatment (exp(ß), 0.805; 95% CI, 0.728-0.890; P < 0.001) and age (exp(ß), 1.005; 95% CI, 1.001-1.009; P = 0.012). A comparable model was selected for predicting the myocardial-to-blood SUVmax ratio using somatostatin analog treatment (P < 0.001) and history of coronary artery disease (P = 0.022). Myocardial uptake was detected in 12.9% (25/193) of Onc-PET scans from patients treated with somatostatin analogs but in 43.4% (59/136) of untreated patients over the median age of 64 y. Myocardial uptake was apparent in all 31 AM-PET scans, with volume and intensity of uptake dramatically higher than in the 137 Onc-PET scans showing myocardial uptake. A myocardial-to-blood SUVmax ratio threshold of 2.20 provided a sensitivity of 87% (27/31) and a specificity of 88% (44/50) for differentiating myocardial uptake between the AM-PET group and an Onc-PET group restricted to patients with clinical characteristics comparable to those of patients in the AM-PET group (≤64 y of age, no coronary artery disease history, and no somatostatin agonists). A myocardial uptake volume threshold of 18 cm3 provided comparable diagnostic accuracy (sensitivity, 84% [26/31]; specificity, 94% [47/50]). Conclusion: Myocardial uptake was detected in 26.9% of somatostatin PET scans recorded for oncology indications. This rate was decreased by somatostatin analog treatments and increased in older individuals. However, somatostatin PET scans, analyzed with the quantitative criterion of uptake intensity or volume, are able to identify AM and to differentiate it from myocardial uptake of other origins.

Asunto(s)

Miocarditis , Miocardio , Octreótido , Somatostatina , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Aguda , Transporte Biológico , Diagnóstico Diferencial , Corazón/diagnóstico por imagen , Miocarditis/diagnóstico por imagen , Miocarditis/metabolismo , Miocardio/metabolismo , Neoplasias/diagnóstico por imagen , Neoplasias/metabolismo , Octreótido/análogos & derivados , Octreótido/metabolismo , Octreótido/farmacocinética , Compuestos Organometálicos/farmacocinética , Compuestos Organometálicos/metabolismo , Tomografía de Emisión de Positrones , Radiofármacos/farmacocinética , Estudios Retrospectivos , Somatostatina/análogos & derivados , Somatostatina/metabolismo

RESUMEN

BACKGROUND: Abnormalities in T cell activation play an important role in the pathogenesis of myocarditis, and persistent T cell responses can lead to autoimmunity and chronic cardiac inflammation, as well as even dilated cardiomyopathy. Although previous work has examined the role of T cells in myocarditis in animal models, the specific mechanism for human cardiomyocytes has not been investigated. METHODS: In this study, we constructed the human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and established the T cell-mediated cardiac injury model by co-culturing with activated CD4 + T or CD8 + T cells that were isolated from peripheral mononuclear blood to elucidate the pathogenesis of myocardial cell injury caused by inflammation. RESULTS: By combination of quantitative proteomics with tissue and cell immunofluorescence examination, we established a proteome profile of inflammatory myocardia from hiPSC-CMs with obvious cardiomyocyte injury and increased levels of lactate dehydrogenase content, creatine kinase isoenzyme MB and cardiac troponin. A series of molecular dysfunctions of hiPSC-CMs was observed and indicated that CD4 + cells could produce direct cardiomyocyte injury by activating the NOD-like receptor signals pathway. CONCLUSIONS: The data presented in our study established a proteome map of inflammatory myocardial based on hiPSC-CMs injury model. These results can provide guidance in the discovery of improved clinical treatments for myocarditis.

Asunto(s)

Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Proteómica , Humanos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/citología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Proteómica/métodos , Proteoma/metabolismo , Linfocitos T/metabolismo , Linfocitos T/citología , Miocarditis/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Técnicas de Cocultivo

RESUMEN

Fibroblasts are essential for building and maintaining the structural integrity of all organs. Moreover, fibroblasts can acquire an inflammatory phenotype to accommodate immune cells in specific niches and to provide migration, differentiation, and growth factors. In the heart, balancing of fibroblast activity is critical for cardiac homeostasis and optimal organ function during inflammation. Fibroblasts sustain cardiac homeostasis by generating local niche environments that support housekeeping functions and by actively engaging in intercellular cross talk. During inflammatory perturbations, cardiac fibroblasts rapidly switch to an inflammatory state and actively communicate with infiltrating immune cells to orchestrate immune cell migration and activity. Here, we summarize the current knowledge on the molecular landscape of cardiac fibroblasts, focusing on their dual role in promoting tissue homeostasis and modulating immune cell-cardiomyocyte interaction. In addition, we discuss potential future avenues for manipulating cardiac fibroblast activity during myocardial inflammation.

Asunto(s)

Fibroblastos , Homeostasis , Miocardio , Humanos , Animales , Fibroblastos/metabolismo , Fibroblastos/patología , Fibroblastos/inmunología , Miocardio/patología , Miocardio/inmunología , Miocardio/metabolismo , Inflamación/metabolismo , Inflamación/patología , Inflamación/inmunología , Miocarditis/inmunología , Miocarditis/patología , Miocarditis/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Comunicación Celular

RESUMEN

Myocarditis is characterized by an influx of inflammatory cells, predominantly of myeloid lineage. The progression of myocarditis to a dilated cardiomyopathy is markedly influenced by TGF-ß signalling. Here, we investigate the role of TGF-ß signalling in inflammatory cardiac macrophages in the development of myocarditis and post-inflammatory fibrosis. Experimental autoimmune myocarditis (EAM) was induced in the LysM-Cre × R26-stop-EYFP × Tgfbr2-fl/fl transgenic mice showing impaired TGF-ß signalling in the myeloid lineage and the LysM-Cre × R26-stop-EYFP control mice. In EAM, immunization led to acute myocarditis on day 21, followed by cardiac fibrosis on day 40. Both strains showed a similar severity of myocarditis and the extent of cardiac fibrosis. On day 21 of EAM, an increase in cardiac inflammatory macrophages was observed in both strains. These cells were sorted and analysed for differential gene expression using whole-genome transcriptomics. The analysis revealed activation and regulation of the inflammatory response, particularly the production of both pro-inflammatory and anti-inflammatory cytokines and cytokine receptors as TGF-ß-dependent processes. The analysis of selected cytokines produced by bone marrow-derived macrophages confirmed their suppressed secretion. In conclusion, our findings highlight the regulatory role of TGF-ß signalling in cytokine production within inflammatory cardiac macrophages during myocarditis.

Asunto(s)

Enfermedades Autoinmunes , Citocinas , Macrófagos , Ratones Transgénicos , Miocarditis , Transducción de Señal , Factor de Crecimiento Transformador beta , Animales , Miocarditis/metabolismo , Miocarditis/inmunología , Miocarditis/patología , Miocarditis/etiología , Factor de Crecimiento Transformador beta/metabolismo , Ratones , Macrófagos/metabolismo , Macrófagos/inmunología , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/patología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Miocardio/metabolismo , Miocardio/patología , Miocardio/inmunología , Fibrosis , Masculino

RESUMEN

Advances in the etiological classification of myocarditis and inflammatory cardiomyopathy (ICM) have reached a consensus. However, the mechanism of myocarditis/ICM remains unclear, which affects the development of treatment and the improvement of outcome. Cellular transcription and metabolic reprogramming, and the interactions between cardiomyocytes and non-cardiomyocytes, such as the immune cells, contribute to the process of myocarditis/ICM. Recent efforts have been made by multi-omics techniques, particularly in single-cell RNA sequencing, to gain a better understanding of the cellular landscape alteration occurring in disease during the progression. This article aims to provide a comprehensive overview of the latest studies in myocarditis/ICM, particularly as revealed by single-cell sequencing.

Asunto(s)

Cardiomiopatías , Miocarditis , Humanos , Miocarditis/fisiopatología , Miocarditis/metabolismo , Cardiomiopatías/etiología , Cardiomiopatías/fisiopatología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Miocardio/patología , Miocardio/metabolismo , Análisis de la Célula Individual/métodos

RESUMEN

Influenza is a significant public health and economic threat around the world. Epidemiological studies have demonstrated a close association between influenza pandemics and cardiovascular mortality. Moreover, it has been shown that there is a decrease in cardiovascular mortality in high-risk patients following vaccination with the influenza vaccine. Here, we have investigated the role of anti-viral STAT1 signaling in influenza-induced myocarditis. Wild-type mice (C57BL/6) were infected with either influenza A/PR/8/34 or control, and cellular response and gene expression analysis from the heart samples were assessed 7 days later. The expression of interferon response genes STAT1, STAT2, Mx1, OASL2, ISG15, chemokines CCL2, CCL3, CXCL9 and CXCL10, and the frequency of neutrophils (CD45+CD11b+Ly6G+) and CD4+ T cells (CD45+CD4+) were all significantly increased in influenza-infected mice when compared to vehicle controls. These data suggest that influenza infection induces interferons, inflammatory chemokines, and cellular recruitment during influenza infection. We further investigated the role of STAT1 in influenza-induced myocarditis. The frequency of neutrophils and the levels of lipocalin 2 were significantly increased in STAT1-/- mice when compared to WT controls. Finally, we investigated the role of Lcn2 in viral-induced myocarditis. We found that in the absence of Lcn2, there was preserved cardiac function in Lcn2-/- mice when compared to WT controls. These data suggest that the absence of Lcn2 is cardioprotective during viral-induced myocarditis.

Asunto(s)

Lipocalina 2 , Ratones Endogámicos C57BL , Miocarditis , Infecciones por Orthomyxoviridae , Factor de Transcripción STAT1 , Animales , Ratones , Lipocalina 2/metabolismo , Lipocalina 2/genética , Ratones Noqueados , Miocarditis/virología , Miocarditis/metabolismo , Miocarditis/etiología , Neutrófilos/metabolismo , Neutrófilos/inmunología , Infecciones por Orthomyxoviridae/complicaciones , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/metabolismo , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT1/genética