Objective To investigate the effect of viral myocarditis serum exosomal miR-320 on apoptosis of cardiomyocytes and its mechanism. Methods The model of viral myocarditis mice was established by intraperitoneal injection of Coxsackie virus B3. Serum exosomes were extracted by serum exosome extraction kit and co-cultured with cardiomyocytes. The uptake of exosomes by cardiomyocytes was detected by laser confocal microscopy. Cardiomyocytes were transfected with miR-320 inhibitor or mimic, and the expression level of miR-320 was detected by real-time quantitative PCR. Flow cytometry was used to detect cardiomyocyte apoptosis rate, and the expression levels of B cell lymphoma 2 (Bcl2) and Bcl2-related X protein (BAX) were tested by Western blot analysis. The prediction of miR-320 target genes and GO and KEGG enrichment analysis were tested by online database. The relationship between miR-320 and its target gene phosphoinositide-3-kinase regulatory subunit 1(Pik3r1) was examined by luciferase reporter gene. The effect of miR-320 on AKT/mTOR pathway protein was detected by Western blot analysis. Results Viral myocarditis serum exosomes promoted cardiomyocyte apoptosis, and increased the level of BAX while the level of Bcl2 was decreased. miR-320 was significantly up-regulated in myocardial tissue of viral myocarditis mice, and both pri-miR-320 and mature of miR-320 were up-regulated greatly in cardiomyocytes. The level of miR-320 in cardiomyocytes treated with viral myocarditis serum exosomes was significantly up-regulated, while transfection of miR-320 inhibitor counteracted miR-320 overexpression and reduced apoptosis rate caused by exosomes. Pik3r1 is the target gene of miR-320, and its overexpression reversed cardiomyocyte apoptosis induced by miR-320 up-regulation. The overexpression of miR-320 inhibited AKT/mTOR pathway activation. Conclusion Viral myocarditis serum exosome-derived miR-320 promotes apoptosis of mouse cardiomyocytes by inhibiting AKT/mTOR pathway by targeting Pik3r1.
Mice ; Animals ; Myocytes, Cardiac ; Phosphatidylinositol 3-Kinase/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Myocarditis/pathology* ; Exosomes/metabolism* ; bcl-2-Associated X Protein/metabolism* ; MicroRNAs/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Apoptosis/genetics*

OBJECTIVE: Immune checkpoint inhibitors (ICI) have significantly improved the treatment efficacy of a variety of malignant tumors. However, patients may experience a series of special side effects during treatments with ICI. Immune-related myositis after ICI treatment is characterized by autoimmune rheumatic and musculoskeletal damage, which is relatively rare. To analyze the clinical characteristics and outcomes of ICI-associated myositis in urological tumors, we summarized the clinical manifestations, electrophysiological and pathological characteristics, treatments and outcomes in 8 patients. METHODS: The clinical data of the 8 patients with immune-related myositis after ICI treatment for urological tumors treated in the Department of Urology, Peking University First Hospital from March 2018 to March 2022 were retrospectively analyzed for demographic characteristics, drug regimen, clinical symptoms, laboratory indices, electromyography examination, pathological manifestations and outcomes. RESULTS: The eight patients included 2 females and 6 males with a median age of 68 years, all treated with ICI for urological neoplasms, including 2 upper tract urothelial carcinoma (UTUC), 3 renal cell carcinoma (RCC), and 3 bladder cancer (BCa). The median time between the first ICI treatment and the detection of immune-related myositis was 39.5 days, and the median duration of treatment was 2 sessions. The main symptoms were muscle pain and weakness, 5 cases with ptosis, 3 cases with secondary rhabdomyolysis, 5 cases with myocarditis, 1 case with myasthenia gravis, and 1 case with enterocolitis. Among them, patients with immune-related myocarditis had a shorter interval from the first anti-programmed cell death protein-1 (PD-1) therapy to the onset of immune-related myositis (P=0.042) compared with patients without myocarditis. The 8 patients had significant elevation of transaminases and muscle enzyme profile indexes, and 5 patients showed positive auto-antibodies. 3 patients had perfected muscle biopsies and showed typical skeletal muscle inflammatory myopathy-like pathological changes with CD3⁺, CD4⁺, CD8⁺, CD20⁺ lymphocytes and CD68⁺ macrophage infiltration. After the diagnosis of immune-related myositis, all the 8 patients immediately discontinued ICI therapy and improved after intravenous administration of methylprednisolone alone or in combination with gamma-globulin. CONCLUSION Immune-related myositis after ICI treatment is an immune-related adverse reactions (irAEs) with unique clinical and pathological features, commonly combined with cardiovascular adverse reactions. Immediate discontinuation of ICI and initiation of glucocorticoid therapy may improve the patient's condition in a timely manner.
Aged ; Antineoplastic Agents, Immunological/adverse effects* ; Carcinoma, Transitional Cell ; Female ; Humans ; Immune Checkpoint Inhibitors/adverse effects* ; Kidney Neoplasms/drug therapy* ; Male ; Myocarditis/drug therapy* ; Myositis/pathology* ; Retrospective Studies ; Urinary Bladder Neoplasms

The study is to investigate effects of andrographolide on experimental autoimmune myocarditis (EAM). Lewis rats were immunized on day 0 with porcine cardiac myosin to establish EAM. The EAM rats were treated with either andrographolide (25, 50, 100 mg/kg/day) or vehicle for 21 days. An antigen-specific splenocytes proliferation assay was performed by using the cells from control rats immunized with cardiac myosin. Survival rates, myocardial pathology and myocardial functional parameters (left ventricle end-diastolic pressure, ± dP/dt and left ventricular internal dimension) of EAM rats received andrographolide were significantly improved. Andrographolide treatment caused an decrease in the infiltration of CD3⁺ and CD14⁺ positive cells in myocardial tissue. Moreover, andrographolide treatment caused a reduction in the plasma levels of tumor necrosis factor-alpha, interleukin-17 (IL-17) and myosin-antibody, and an increase in the level of IL-10 in EAM rats. Oral administration of andrographolide resulted in the decreased expression of p-PI3K, p-Akt without any change of PI3K and Akt. Further results indicate andrographolide significantly inhibited myosin-induced proliferation in splenocytes, and this effect was inhibited by co-treatment of SC79 (Akt activator). Our data indicate andrographolide inhibits development of EAM, and this beneficial effect may be due to powerful anti-inflammatory activity and inhibitory effect on PI3K/Akt pathway.
Administration, Oral ; Animals ; Cardiac Myosins ; Interleukin-10 ; Interleukin-17 ; Models, Animal* ; Myocarditis* ; Pathology ; Plasma ; Rats* ; Survival Rate ; Tumor Necrosis Factor-alpha

Group B coxsackieviruses (CVBs) are a group of common human pathogens producing various clinical symptoms. Although the virology of CVB is well known, there is limited information on viral pathogenesis and the relationship between clinical symptoms and viral phenotype, particularly for CVB type 2 (CVB2). In 2004 in Korea, two CVB2 strains were isolated: CB2/04/279 from stool of an acute myocarditis patient with heart failure and CB2/04/243 from an aseptic meningitis patient. In this study, a high degree of homology was observed between the CB2/04/279 and CB2/04/243 full genome sequences. The two Korean CVB2 isolates had 93.1% homology compared to 82.1%–82.5% nucleotide sequence identity with the cardiovirulence-associated reference CVB strain Ohio-1 (CVB/O). CVB2-induced pathogenesis was analyzed, focusing on virus-induced pathology of various tissues in 4-week-old BALB/c inbred male mice. Myocarditis developed and extensive pancreatic inflammation was observed in all mice infected with CB2/04/279 or CVB/O, but not in animals infected with CB2/04/243. This is the first report of the full-genomic sequence and pathogenesis of the CVB2 strain isolated from an acute myocarditis patient in Korea.
Animals ; Base Sequence ; Enterovirus ; Genome ; Heart Failure ; Humans ; Inflammation ; Korea* ; Male ; Meningitis, Aseptic* ; Mice* ; Myocarditis* ; Pathology ; Phenotype ; Virology

During 2006, H5N1 HPAI caused an epizootic in wild birds, resulting in a die-off of Laridae in the Novosibirsk region at Chany Lake. In the present study, we infected common gulls (Larus canus) with a high dose of the H5N1 HPAI virus isolated from a common gull to determine if severe disease could be induced over the 28 day experimental period. Moderate clinical signs including diarrhea, conjunctivitis, respiratory distress and neurological signs were observed in virus-inoculated birds, and 50% died. The most common microscopic lesions observed were necrosis of the pancreas, mild encephalitis, mild myocarditis, liver parenchymal hemorrhages, lymphocytic hepatitis, parabronchi lumen hemorrhages and interstitial pneumonia. High viral titers were shed from the oropharyngeal route and virus was still detected in one bird at 25 days after infection. In the cloaca, the virus was detected sporadically in lower titers. The virus was transmitted to direct contact gulls. Thus, infected gulls can pose a significant risk of H5N1 HPAIV transmission to other wild migratory waterfowl and pose a risk to more susceptible poultry species. These findings have important implications regarding the mode of transmission and potential risks of H5N1 HPAI spread by gulls.
Animals ; Birds ; Charadriiformes* ; Cloaca ; Conjunctivitis ; Diarrhea ; Encephalitis ; Hemorrhage ; Hepatitis ; Influenza A Virus, H5N1 Subtype* ; Lakes ; Liver ; Lung Diseases, Interstitial ; Myocarditis ; Necrosis ; Pancreas ; Pathology* ; Poultry ; Virulence

Eosinophilic myocarditis is a disease characterized by eosinophilic infiltration of the myocardium, consisting of acute necrotic stage, thrombotic stage, and fibrotic stage. Although T1 mapping has been increasingly used in various cardiac pathologies, there has been no report of T1 mapping in eosinophilic myocarditis. We report a case of 75-year-old female with eosinophilic myocarditis, whose cardiac magnetic resonance imaging included native T1 mapping, in which apical thrombi were distinctly seen as areas with decreased T1 values, next to areas of inflammation seen as increased T1 value in subendocardium.
Aged ; Churg-Strauss Syndrome* ; Eosinophils* ; Female ; Humans ; Inflammation ; Magnetic Resonance Imaging ; Myocarditis* ; Myocardium ; Necrosis ; Pathology ; Thrombosis

OBJECTIVETo investigate the effect of tranilast on myocardial fibrosis in mice with viral myocarditis (VMC).

METHODSMale balb/c mice (n=72) were randomly divided into control, VMC and tranilast groups (n=24 each). In the VMC and tranilast groups, the mice were infected with Coxsackie virus B3 (CVB3) to prepare VMC model, while the control group was treated with Eagle's medium. After modeling, the tranilast group was administrated with tranilast [200 mg/(kg.d)] until the day before sampling. On days 7, 14 and 28 after CVB3 or Eagle's medium infection, heart specimens (n=8) were taken and examined after Toluidine blue staining and Nissl staining for counts of mast cells (MC), hematoxylin-eosin staining for myocardial pathological changes, and Masson staining for myocardial fibrosis. The expression of CTGF and type I collagen (Col I) in the myocardial tissue was measured by RT-PCR and Western blot. The correlations of CTGF mRNA expression with MC counts and Col I expression were analyzed.

RESULTSThe myocardial pathological changes and collagen volume fraction in the VMC group were significantly higher than in the control group at all three time points (P<0.05). Tranilast treatment significantly decreased the myocardial pathological changes and collagen volume fraction compared with the VMC group (P<0.05). The mRNA and protein expression of CTGF and Col I increased in the VMC group compared with the control group, and the increases were reduced with tranilast treatment (P<0.05). The number of MC was positively correlated to CTGF mRNA expression on the 7th day and 14th day (r=0.439, P=0.049) in the VMC group. There were positive correlations between the mRNA expression of Col I and CTGF on the 7th day and 14th day (r=0.646, P=0.007) and the 28th day (r=0.326, P=0.031).

CONCLUSIONSTranilast may inhibit the aggregation of MC and down-regulate the expression of CTGF, relieving myocardial fibrosis of mice with VMC.

Animals ; Collagen Type I ; genetics ; Connective Tissue Growth Factor ; genetics ; Coxsackievirus Infections ; drug therapy ; Enterovirus B, Human ; Fibrosis ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; drug therapy ; Myocardium ; pathology ; RNA, Messenger ; analysis ; ortho-Aminobenzoates ; pharmacology

OBJECTIVETo identify clinical and pathological features of giant cell myocarditis.

METHODSClinical presentation and follow-up data of three patients with giant cell myocarditis were collected.Gross, histopathological, immunohistological and ultrastructural findings of extransplantated hearts of the patients were documented.

RESULTSGrossly, multifocal involvement of the myocardium with variably dilated cardiac chambers were observed in all 3 cases.Histological examination revealed pronounced focal inflammatory infiltrates with multinucleated giant cells. Multinucleated giant cells were positive for CD68 and CD11b immunostains but were negative for CD163 in all cases. Transmission electron microscopy showed that the multinucleated giant cells derived from fusion of several macrophages with adherent lymphocytes and secretary cells. Clinically, the overall patient condition improved in all three cases after heart transplantation.One patient experienced acute cellular rejection (2R level) 4 months after transplantation, but recovered after treatment. One patient developed multinucleated giant cells observed in heart biopsy two weeks after transplantation.

CONCLUSIONSGiant-cell myocarditis is a rare disease of adult, and cardiac transplantation could improve the clinical outcome. Multinucleated giant cell in the myocarditis lesions were derived from macrophages, likely participating in the immune response. Endomyocardial biopsy is important for the diagnosis of giant cell myocarditis.

Acute Disease ; Adult ; Biopsy ; Giant Cells ; pathology ; ultrastructure ; Heart Transplantation ; Humans ; Lymphocytes ; pathology ; Macrophages ; pathology ; Microscopy, Electron, Transmission ; Myocarditis ; pathology ; Myocardium ; pathology ; ultrastructure

OBJECTIVETo investigate the dynamic expression and role of vitamin D receptor (VDR) in the myocardium of mice with viral myocarditis (VMC).

METHODSOne hundred and twenty 4-week-old male BALB/c mice were selected and assigned into control (n=40) and experimental groups (n=80). The mice in the experimental group were injected intraperitoneally with Coxsackievirus B3 to establish the model of VMC, while the mice in the control group were injected intraperitoneally with an equal volume of DMEM solution. Fifteen mice in the experimental group and ten mice in the control group were sacrificed at 3, 7, 14, or 28 days after injection, and the myocardial specimens were obtained. The dynamic expression of VDR in the myocardium was determined by the immunohistochemical technique. The pathological changes in the myocardium were examined using hematoxylin and eosin staining.

RESULTSIn the experimental group, the mice had significantly increased expression of VDR after virus injection (P<0.01); the expression of VDR reached the peak at 7 days after injection, and then declined gradually; the expression of VDR remained high at 28 days after injection. At 3, 7, 14, and 28 days after injection, the expression of VDR in the experimental group was significantly higher than that in the control group (P<0.01). Moreover, in the experimental group, the changes in the pathological score of the myocardium were in accordance with the changes in the expression of VDR; the expression level of VDR in the myocardium was positively correlated with the pathological changes in the myocardium in the experimental group (P<0.01).

CONCLUSIONSVDR may be involved in the inflammatory-immune process in the pathogenesis of VMC.

Animals ; Coxsackievirus Infections ; metabolism ; Enterovirus B, Human ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; metabolism ; pathology ; Myocardium ; chemistry ; pathology ; Receptors, Calcitriol ; analysis ; physiology

Pericarditis and myocarditis are characterised by electrocardiographic changes and elevated cardiac enzymes, respectively, and patients with perimyocarditis often complain of chest discomfort. These findings are nonspecific and often lead to diagnostic difficulties, as ST-elevation myocardial infarction commonly presents in a similar fashion. Clinical differentiation between perimyocarditis and myocardial infarction are especially important because adverse side effects can occur if reperfusion therapy is administered for a patient with acute pericarditis or if a diagnosis of acute myocardial infarction is missed. We herein describe a case of perimyocarditis with ST elevation and raised cardiac markers, which led to two emergency coronary angiographies that were subsequently found to be normal. We include the three serial electrocardiographies (ECGs) performed to show the characteristic features of perimyocarditis and further discuss the importance of identifying typical and atypical ECG features of pericarditis.
Acute Disease ; Aged ; Biopsy ; Blood Pressure ; Coronary Angiography ; Electrocardiography ; Female ; Humans ; Myocardial Infarction ; pathology ; Myocarditis ; diagnosis ; physiopathology