Inhibition of Calpain Alleviates Apoptosis in Coxsackievirus B3-induced Acute Virus Myocarditis Through Suppressing Endoplasmic Reticulum Stress.

Virus myocarditis (VMC) is a common cardiovascular disease and a major cause of sudden death in young adults. However, there is still a lack of effective treatments. Our previous studies found that calpain activation was involved in VMC pathogenesis. This study aims to explore the underlying mechanisms further. Neonatal rat cardiomyocytes (NRCMs) and transgenic mice overexpressing calpastatin (Tg-CAST), the endogenous calpain inhibitor, were used to establish VMC model. Hematoxylin and eosin and Masson staining revealed inflammatory cell infiltration and fibrosis. An ELISA array detected myocardial injury. Cardiac function was measured using echocardiography. CVB3 replication was assessed by capsid protein VP1. Apoptosis was measured by TUNEL staining, flow cytometry, and western blot. The endoplasmic reticulum (ER) stress-related proteins were detected by western blot. Our data showed that CVB3 infection resulted in cardiac injury, as evidenced by increased inflammatory responses and fibrosis, which induced myocardial apoptosis. Inhibiting calpain, both by PD150606 and calpastatin overexpression, could attenuate these effects. Furthermore, ER stress was activated during CVB3 infection. However, calpain inhibition could downregulate some ER stress-associated protein levels such as GRP78, pancreatic ER kinase-like ER kinase (PERK), and inositol-requiring enzyme-1α (IRE-1α), and ER stress-related apoptotic factors, during CVB3 infection. In conclusion, calpain inhibition attenuated CVB3-induced myocarditis by suppressing ER stress, thereby inhibiting cardiomyocyte apoptosis.

Macrophage AXL receptor tyrosine kinase inflames the heart after reperfused myocardial infarction.

Tyro3, AXL, and MerTK (TAM) receptors are activated in macrophages in response to tissue injury and as such have been proposed as therapeutic targets to promote inflammation resolution during sterile wound healing, including myocardial infarction. Although the role of MerTK in cardioprotection is well characterized, the unique role of the other structurally similar TAMs, and particularly AXL, in clinically relevant models of myocardial ischemia/reperfusion infarction (IRI) is comparatively unknown. Utilizing complementary approaches, validated by flow cytometric analysis of human and murine macrophage subsets and conditional genetic loss and gain of function, we uncover a maladaptive role for myeloid AXL during IRI in the heart. Cross signaling between AXL and TLR4 in cardiac macrophages directed a switch to glycolytic metabolism and secretion of proinflammatory IL-1ß, leading to increased intramyocardial inflammation, adverse ventricular remodeling, and impaired contractile function. AXL functioned independently of cardioprotective MerTK to reduce the efficacy of cardiac repair, but like MerTK, was proteolytically cleaved. Administration of a selective small molecule AXL inhibitor alone improved cardiac healing, which was further enhanced in combination with blockade of MerTK cleavage. These data support further exploration of macrophage TAM receptors as therapeutic targets for myocardial infarction.

Effects of Xinjierkang on Nrf2/HO-1 expression in viral myocarditis mice models.

In this study, the changes of Nrf2/HO-1 and cytokines TNF-α, IL-6, IL-17 and IL-1ß in cardiac muscle cells of Viral myocarditis (VMC) mice were detected in order to clarify the mechanism of action of Xinjierkang (XJEK). One hundred and fifty healthy male BALBC mice were randomly divided into the normal group, model group, low-, medium- and high-dose XJEK groups, with 30 in each group. Replication of the VMC model in mice inoculated with CVB3m. Serum inflammatory factors TNF-α, IL-6, IL-17 and IL-1ß, Nrf2 and HO-1 protein levels in myocardial tissue were compared. The results showed that no apoptotic cells were found in the myocardium of normal mice. The percentage of cardiomyocyte apoptosis in the low, medium and high dose groups of XJEK was significantly lower than the model group (P <0.05). At 3, 7, 14, 21, and 28 days after inoculation, compared with the normal group, the TNF-α, IL-6, IL-17 and IL-1ß levels in the model group significantly increased (p < 0.05). After the administration of XJEK, compared with the model group, the TNF-α, IL-6, IL-17, and IL-1ß levels in the low-, middle-, and high-dose XJEK groups significantly decreased (p < 0.05). At 28 days after inoculation, compared with the normal group, the expressions of Nrf2 and HO-1 proteins in the myocardial tissue of the model group were significantly down-regulated (p < 0.05); and compared with the model group, the expressions of Nrf2 and HO-1 proteins in the low-, medium-, and high-dose XJEK groups were significantly up-regulated (p < 0.05) in a concentration-dependent manner. In conclusion, XJEK can prevent myocardial injury in VMC mice, and its mechanism of action may be related to improving myocardial cell apoptosis, inhibiting inflammatory response, and up-regulating the expression of Nrf2 and HO-1 proteins in myocardial tissue.

Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Platform to Study SARS-CoV-2 Related Myocardial Injury.

BACKGROUND: SARS-CoV-2 infection is associated with myocardial injury, but there is a paucity of experimental platforms for the condition.Methods and Results:Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) infected by SARS-CoV-2 for 3 days ceased beating and exhibited cytopathogenic changes with reduced viability. Active viral replication was evidenced by an increase in supernatant SARS-CoV-2 and the presence of SARS-CoV-2 nucleocaspid protein within hiPSC-CMs. Expressions of BNP, CXCL1, CXCL2, IL-6, IL-8 and TNF-α were upregulated, while ACE2 was downregulated. CONCLUSIONS: Our hiPSC-CM-based in-vitro SARS-CoV-2 myocarditis model recapitulated the cytopathogenic effects and cytokine/chemokine response. It could be exploited as a drug screening platform.

Folate Receptor ß-Targeted PET Imaging of Macrophages in Autoimmune Myocarditis.

Currently available imaging techniques have limited specificity for the detection of active myocardial inflammation. Aluminum 18F-labeled 1,4,7-triazacyclononane-N,N',N″-triacetic acid conjugated folate (18F-FOL) is a PET tracer targeting folate receptor ß (FR-ß), which is expressed on activated macrophages at sites of inflammation. We evaluated 18F-FOL PET for the detection of myocardial inflammation in rats with autoimmune myocarditis and studied the expression of FR-ß in human cardiac sarcoidosis specimens. Methods: Myocarditis was induced by immunizing rats (n = 18) with porcine cardiac myosin in complete Freund adjuvant. Control rats (n = 6) were injected with Freund adjuvant alone. 18F-FOL was intravenously injected, followed by imaging with a small-animal PET/CT scanner and autoradiography. Contrast-enhanced high-resolution CT or 18F-FDG PET images were used for coregistration. Rat tissue sections and myocardial autopsy samples from 6 patients with cardiac sarcoidosis were studied for macrophages and FR-ß. Results: The myocardium of 10 of 18 immunized rats showed focal macrophage-rich inflammatory lesions, with FR-ß expression occurring mainly in M1-polarized macrophages. PET images showed focal myocardial 18F-FOL uptake colocalizing with inflammatory lesions (SUVmean, 2.1 ± 1.1), whereas uptake in the remote myocardium of immunized rats and controls was low (SUVmean, 0.4 ± 0.2 and 0.4 ± 0.1, respectively; P < 0.01). Ex vivo autoradiography of tissue sections confirmed uptake of 18F-FOL in myocardial inflammatory lesions. Uptake of 18F-FOL in inflamed myocardium was efficiently blocked by a nonlabeled FR-ß ligand folate glucosamine in vivo. The myocardium of patients with cardiac sarcoidosis showed many FR-ß-positive macrophages in inflammatory lesions. Conclusion: In a rat model of autoimmune myocarditis, 18F-FOL shows specific uptake in inflamed myocardium containing macrophages expressing FR-ß, which were also present in human cardiac sarcoid lesions. Imaging of FR-ß expression is a potential approach for the detection of active myocardial inflammation.

Effects of Cr(VI) exposure on electrocardiogram, myocardial enzyme parameters, inflammatory factors, oxidative kinase, and ATPase of the heart in Chinese rural dogs.

Heavily chromium-polluted areas, where people are prohibited from entering, are paradises for stray dogs. In this study, stray dogs were used to study the effects of chromium exposure on the heart of dogs in severely Cr(VI)-contaminated rural areas of China. The dogs were given water (control), low dose (L, 0.92 mg/kg), medium dose (M, 1.15 mg/kg), and high dose (H, 1.38 mg/kg) of Cr(VI). The changes of electrocardiogram (ECG), myocardial enzyme parameters, inflammatory factors, oxidative kinase, and ATPase were measured to determine the toxicity of chromium on the heart of dogs. Results showed that the ST segment of ECG increased significantly, and the amplitude of T wave increased in the experimental group. The myocardial enzyme (CK-MB, AST, CK, and LDH) content in groups M and H increased significantly over time. The values of CAT, T-SOD, IL-10, and ATPase (K+-Na+-ATPase and Ca2+-Mg2+-ATPase) decreased with the increase of Cr(VI) dose, and the content of MDA, IL-1ß, IL-8, and TNF-α increased with the increase of Cr(VI) dose. Our study suggested that the heart of Chinese rural dog was damaged by Cr(VI), and Cr(VI) could cause oxidative damage and alteration of ATPase content in dogs.

Cross-platform metabolic profiling deciphering the potential targets of Shenfu injection against acute viral myocarditis in mice.

Acute viral myocarditis (AVMC) is typically caused by cardiotropic viral infection. There is a paucity of specific treatment options available with proven efficacy. Chinese patented pharmaceutical product Shenfu injection (SFI) has potent efficacy on treating AVMC in clinical practice. However, the molecular mechanism is still unknown. We employed cross-platform metabolomics combined with computational systems analysis, based on reversed-phase liquid chromatography-mass spectrometry (RPLC-MS), hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) and gas chromatography-mass spectrometry (GC-MS), to deciphering the targeted metabolic pathways of SFI against AVMC induced by coxsackievirus B3 (CVB3). Quantitative real-time PCR (qRT-PCR) technique was further applied to determining the expressions of the key genes associated with the SFI-targeted metabolic pathways. We have identified 48 significantly changed metabolites related to CVB3-induced AVMC, and SFI can significantly regulate the abnormalities of 33 metabolites and 9 relevant enzymes. Combined metabolic pathway enrichment and topology analyses revealed that the mechanisms of SFI against CVB3-induced AVMC may be attributed to modulating the disordered homeostasis of sphingolipid metabolism, glycerophospholipid metabolism, arachidonic acid metabolism, tryptophan metabolism, and TCA cycle. It provides new experimental information on the pathogenesis of AVMC, unravels the potential targeted metabolic pathways of SFI against AVMC on the whole metabolic network and highlights the importance of metabolomics combined with computational systems analysis as a potential tool for deciphering drug-targeted metabolic pathways.

The Falconoid Luteolin Mitigates the Myocardial Inflammatory Response Induced by High-Carbohydrate/High-Fat Diet in Wistar Rats.

Luteolin is a major component of many medicinal plants and traditional medicines. The current study aims at testing its protective effect against high-carbohydrate/high-fat (HCHF) diet-induced cardiac dysfunction in rats. Male Wistar rats were divided into six groups as follows: control group that received standard rat chow, group received HCHF diet (~ 30% carbohydrate and 42% fat) daily for 16 weeks, and four groups received HCHF diet concurrently with luteolin (10, 25, 50 or 100 mg/kg; 10% w/v suspension in 0.9% NaCl) daily from the first week by oral gavage. Body weight was measured weekly. At the end of the study, histopathological examinations of stained heart sections were carried out. Lipid profile, oxidative stress, and cardiac function biomarkers were measured. Furthermore, neurohumoral mediators and inflammatory cytokines (TNF-α, IL-18) were assigned. Results showed a significant improvement in cardiac function, tissue integrity, and a decrease in the compensatory neurohumoral mediators by luteolin 50 and 100 mg/kg. In addition, a significant (P < 0.05) decrease in collagen deposition, fibrosis percentage, lipid peroxidation, and inflammatory cells (macrophages and lymphocytes) infiltration was observed. Tested doses of luteolin decreased lipid peroxidation and elevated the endogenous antioxidant biomarkers (reduced glutathione and superoxide dismutase) significantly (P < 0.05). Finally, luteolin decreased TNF-α and IL-18 (P < 0.001) in a dose-dependent manner. It can be concluded that luteolin has a cardioprotective effect against HCHF diet-induced myocardial inflammation through antioxidant anti-inflammatory mechanisms.

Effect of QiShenYiQi pill on myocardial collagen metabolism in experimental autoimmune myocarditis rats.

OBJECTIVE: To observe the effect of QiShenYiQi pill (QSYQ) on myocardial collagen metabolism in experimental autoimmune myocarditis rats, and to explore its mechanism of action. METHODS: Lewis rats underwent the injection of myocardial myosin mixed with freund's complete adjuvant were randomized into three groups: model, valsartan and QSYQ groups. And we treated rats which were injected phosphate buffered saline (PBS) mixed with freund's complete adjuvant as control group. Rats were intervened and euthanized at 4 and 8 weeks. We use alkaline hydrolysis to detect the content of myocardial hydroxyproline (HYP), and ELISA to detect the level of serum procollagen type I carboxyterminal peptide (PICP), procollagen type III amino-terminal peptide (PIIINP), and collagen C telopeptide type I (CTX-I). Myocardial MMP-1 and TIMP-1 protein expression was detected by immunohistochemistry, and myocardial MMP-1 and TIMP-1 mRNA expression was detected by real-time qPCR. RESULTS: QSYQ reduced the content of myocardial HYP, and this reduction was greater over time. QSYQ also reduced the serum concentration of PICP, PIIINP, CTX-I and the PICP/PIIINP ratio, which further reduced over time, whereas its effect on lowering PICP was significantly greater than that of valsartan at 4 and 8 weeks, and lowering CTX-I was significantly greater than that of valsartan at 8 weeks. In addition, after 4 weeks, QSYQ enhanced the protein and mRNA expression of MMP-1 and TIMP-1, and its effect on highering TIMP-1 was significantly greater than that of valsartan, whereas there was no significant difference in the expression of myocardial MMP-1 or TIMP-1 at 8 weeks. QSYQ reduced the ratio of MMP-1/TIMP-1, which further reduced over time, and the effect of QYSQ was significantly greater than that of valsartan after 4 weeks. CONCLUSION: This study provides evidence that QSYQ can reduce the rate of myocardial collagen synthesis and degradation. It also effectively improved the degree of myocardial fibrosis in experimental autoimmune myocarditis rats and it had a tendency to have a greater effect with longer treatment duration, which is related to the mechanism of regulation of MMP-1 and TIMP-1 expression in the myocardial rat.

Green Tea Polyphenol Epigallocatechin-3-gallate-Alleviated Coxsackievirus B3-induced Myocarditis Through Inhibiting Viral Replication but Not Through Inhibiting Inflammatory Responses.

Viral myocarditis, which is mainly caused by coxsackievirus B3 (CVB3), affects about 5%-20% of the world population and still lacks efficient treatments. Green tea, a tonic and healthful beverage that was originated in ancient China, has been receiving considerable attention for its protective effect on cardiovascular diseases in recent years. In the present investigation, we aimed to explore the effect of green tea polyphenol epigallocatechin-3-gallate (EGCG) on CVB3-induced myocarditis and its underlying mechanism. Our study showed that EGCG could alleviate CVB3-induced myocarditis as evidenced by less cardiac injury and higher survival rate. Furthermore, we found that EGCG failed to downregulate the expression of inflammatory cytokines but could significantly inhibit the replication of CVB3. Furthermore, we found that EGCG treatment could downregulate the protein expression level of coxsackievirus and adenovirus receptor, the major receptor for CVB3 to infect cardiac myocytes. In conclusion, our data indicated that EGCG could ameliorate CVB3-induced myocarditis through inhibiting viral replication, which might provide a potential novel therapeutic strategy for viral myocarditis.

Cacao polyphenols ameliorate autoimmune myocarditis in mice.

Myocarditis is a clinically severe disease; however, no effective treatment has been established. The aim of this study was to determine whether cacao bean (Theobroma cacao) polyphenols ameliorate autoimmune myocarditis. We used an experimental autoimmune myocarditis (EAM) model in Balb/c mice. Mice with induced EAM were treated with a cacao polyphenol extract (CPE, n=12) or vehicle (n=12). On day 21, hearts were harvested and analyzed. Elevated heart weight to body weight and fibrotic area ratios as well as high cardiac cell infiltration were observed in the vehicle-treated EAM mice. However, these increases were significantly suppressed in the CPE-treated mice. Reverse transcriptase-PCR revealed that mRNA expressions of interleukin (Il)-1ß, Il-6, E-selectin, vascular cell adhesion molecule-1 and collagen type 1 were lower in the CPE group compared with the vehicle group. The mRNA expressions of nicotinamide adenine dinucleotide phosphate-oxidase (Nox)2 and Nox4 were increased in the vehicle-treated EAM hearts, although CPE treatment did not significantly suppress the transcription levels. However, compared with vehicle treatment of EAM hearts, CPE treatment significantly suppressed hydrogen peroxide concentrations. Cardiac myeloperoxidase activity, the intensity of dihydroethidium staining and the phosphorylation of nuclear factor-κB p65 were also lower in the CPE group compared with the vehicle group. Our data suggest that CPE ameliorates EAM in mice. CPE is a promising dietary supplement to suppress cardiovascular inflammation and oxidative stress.

Antagonistic Interplay between MicroRNA-155 and IL-10 during Lyme Carditis and Arthritis.

MicroRNA-155 has been shown to play a role in immune activation and inflammation, and is suppressed by IL-10, an important anti-inflammatory cytokine. The established involvement of IL-10 in the murine model of Borrelia burgdorferi-induced Lyme arthritis and carditis allowed us to assess the interplay between IL-10 and miR-155 in vivo. As reported previously, Mir155 was highly upregulated in joints from infected severely arthritic B6 Il10-/- mice, but not in mildly arthritic B6 mice. In infected hearts, Mir155 was upregulated in both strains, suggesting a role of miR-155 in Lyme carditis. Using B. burgdorferi-infected B6, Mir155-/-, Il10-/-, and Mir155-/- Il10-/- double-knockout (DKO) mice, we found that anti-inflammatory IL-10 and pro-inflammatory miR-155 have opposite and somewhat compensatory effects on myeloid cell activity, cytokine production, and antibody response. Both IL-10 and miR-155 were required for suppression of Lyme carditis. Infected Mir155-/- mice developed moderate/severe carditis, had higher B. burgdorferi numbers, and had reduced Th1 cytokine expression in hearts. In contrast, while Il10-/- and DKO mice also developed severe carditis, hearts had reduced bacterial numbers and elevated Th1 and innate cytokine expression. Surprisingly, miR-155 had little effect on Lyme arthritis. These results show that antagonistic interplay between IL-10 and miR-155 is required to balance host defense and immune activation in vivo, and this balance is particularly important for suppression of Lyme carditis. These results also highlight tissue-specific differences in Lyme arthritis and carditis pathogenesis, and reveal the importance of IL-10-mediated regulation of miR-155 in maintaining healthy immunity.

Antioxidant defense is increased in aged hearts following omega-3 supplementation in the absence of changes in inflammation.

The purpose of this study was to determine the effect of a 15-week omega-3 rich diet on age-related differences in myocardial antioxidant defense and inflammation. 20 mature (M) (6 mo.) and 20 old (O) (15 mo.) male Fisher 344 rats were assigned to two diet groups: Control (CON) or Fish Oil (FO). Following the diet, animals were sacrificed and left ventricular (LV) heart tissue was harvested for biochemical assays and western blot analysis. No differences were observed in expression of LV interleukin-6 (IL-6) and tumor necrosis factor-alpha as well as hydrogen peroxide (H(2)O(2)) production between MCON and OCON. However, LV catalase protein expression and activity were increased in OCON vs. MCON and accompanied by increased expression of superoxide dismutase (SOD)-1. In contrast, LV IL-6 was lower in MFO vs. old rats, and LV H(2)O(2) was decreased in MFO and OFO relative to respective control groups. Protein expression and activity of LV catalase and SOD-1 expression were increased in OFO similarly to OCON, but LV SOD activity was also increased in OFO vs. mature rats. In summary, FO supplementation increased myocardial antioxidant defense in all animals and augmented age-associated increases in antioxidant capacity in the absence of changes in inflammation.

Human induced pluripotent stem cell-derived cardiomyocytes as an in vitro model for coxsackievirus B3-induced myocarditis and antiviral drug screening platform.

RATIONALE: Viral myocarditis is a life-threatening illness that may lead to heart failure or cardiac arrhythmias. A major causative agent for viral myocarditis is the B3 strain of coxsackievirus, a positive-sense RNA enterovirus. However, human cardiac tissues are difficult to procure in sufficient enough quantities for studying the mechanisms of cardiac-specific viral infection. OBJECTIVE: This study examined whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) could be used to model the pathogenic processes of coxsackievirus-induced viral myocarditis and to screen antiviral therapeutics for efficacy. METHODS AND RESULTS: hiPSC-CMs were infected with a luciferase-expressing coxsackievirus B3 strain (CVB3-Luc). Brightfield microscopy, immunofluorescence, and calcium imaging were used to characterize virally infected hiPSC-CMs for alterations in cellular morphology and calcium handling. Viral proliferation in hiPSC-CMs was quantified using bioluminescence imaging. Antiviral compounds including interferonß1, ribavirin, pyrrolidine dithiocarbamate, and fluoxetine were tested for their capacity to abrogate CVB3-Luc proliferation in hiPSC-CMs in vitro. The ability of these compounds to reduce CVB3-Luc proliferation in hiPSC-CMs was consistent with reported drug effects in previous studies. Mechanistic analyses via gene expression profiling of hiPSC-CMs infected with CVB3-Luc revealed an activation of viral RNA and protein clearance pathways after interferonß1 treatment. CONCLUSIONS: This study demonstrates that hiPSC-CMs express the coxsackievirus and adenovirus receptor, are susceptible to coxsackievirus infection, and can be used to predict antiviral drug efficacy. Our results suggest that the hiPSC-CM/CVB3-Luc assay is a sensitive platform that can screen novel antiviral therapeutics for their effectiveness in a high-throughput fashion.

Effects of HMG-CoA reductase inhibitor on experimental autoimmune myocarditis.

PURPOSE: Myocarditis is an acute inflammatory disease of the heart and is often a precursor of dilated cardiomyopathy. Experimental autoimmune myocarditis (EAM) has been used as a model for human myocarditis. The purpose of this study was to investigate the therapeutic role of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, rosuvastatin, on the development of EAM. METHODS: Experimental autoimmune myocarditis was induced in BALB/c mice by immunization with murine cardiac α-myosin heavy chain (MyHc-α(614-629) [Ac-SLKLMATLFSTYASAD-OH]). High-dose (10 mg/kg/day) or low-dose (1 mg/kg/day) rosuvastatin or vehicle was administered orally by gastric gavage to mice with EAM from day 0 to day 21 after immunization. On day 21 after immunization, echocardiography was carried out and the severity of myocarditis was detected by histopathological evaluation. Levels of serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 were measured by ELISA. Histopathology was performed using haematoxylin and eosin. With apoptosis examined by Tunel, the expression of active caspase-3 in myocardium was investigated by immunohistochemistry. RESULTS: Rosuvastatin attenuated the histopathological severity of myocarditis. Cardiac function was improved in the two rosuvastatin-treated groups compared to the non-treated EAM group (LVFS: high-dose rosuvastatin group [group H], 0.38 ± 0.10%; low-dose rosuvastatin group [group L], 0.34 ± 0.06%; non-treated EAM group [group N], 0.29 ± 0.07%. LVEF: group H, 0.80 ± 0.09%; group L, 0.71 ± 0.07%; group N, 0.68 ± 0.07%). Furthermore, treatment with rosuvastatin decreased the expression levels of TNF-α (group H, 65.19 ± 7.06 pg/ml; group L, 108.20 ± 5.28 pg/ml; group N, 239.34 ± 11.65 pg/ml) and IL-6 (group H, 14.33 ± 2.15 pg/ml; group L, 19.67 ± 3.04 pg/ml; group N, 40.39 ± 7.17 pg/ml). The rates of expression of active Caspase-3 and myocardial apoptosis were positively correlated with the scores for myocardial pathology. CONCLUSIONS: These results demonstrate that administration of rosuvastatin can ameliorate EAM progression, inhibit apoptosis of cardiomyocytes, and preserve cardiac output, and they also suggest rosuvastatin may be a promising novel therapeutic strategy for the clinical treatment of myocarditis.

[Effects of astragaloside on IGF-1 and associated protein expression in mice with acute viral myocarditis].

OBJECTIVE: To study the effects of astragaloside on the expression of insulin-like growth factor-1 (IGF-1) and associated proteins in mice with viral myocarditis. METHODS: Sixty-five 4-week-old BALB/C mice were randomly divided into 5 groups: normal control, astragaloside control, untreated myocarditis, low-dose and high-dose astragaloside-treated myocarditis. The BALB/C mice in the later three groups were intraperitoneally injected with CVB3. The low-dose and high-dose astragaloside-treated myocarditis groups were given astragaloside of 0.07 and 0.6 mg/kg•d, respectively by intragastric administration. Fifteen days later, the samples of blood and muscular tissues were obtained. The expression of IGF-1 in plasma was measured using ELISA. The levels of IGF-1 and associated proteins in muscular tissues were measured by immunohistochemistry. The expression of IGF-1 mRNA in muscular tissues was examined by RT-polymerase chain reaction (RT-PCR). RESULTS: The expression of IGF-1 and associated proteins increased significantly in mice infected with CVB3. High-dose astragaloside treatment reduced the expression of IGF-1 and associated proteins, but low-dose astragaloside did not. CONCLUSIONS: High-dose astragaloside may reduce the expression of IGF-1 and associated proteins in mice with acute viral myocarditis, possibly thus providing protective effects on muscular tissues.

Inhibition of cardiac oxidative and endoplasmic reticulum stress-mediated apoptosis by curcumin treatment contributes to protection against acute myocarditis.

Curcumin is used anecdotally as an herb in traditional Indian and Chinese medicine. In the present study, the effects and possible mechanism of curcumin in experimental autoimmune myocarditis (EAM) rats were further investigated. They were divided randomly into a treatment and vehicle group, and orally administrated curcumin (50 mg/kg/day) and 1% gum arabic, respectively, for 3 weeks after myosin injection. The results showed that curcumin significantly suppressed the myocardial protein expression of inducible nitric oxide synthase (iNOS) and the catalytic subunit of nicotinamide adenine dinucleotide phosphate reduced (NADPH) oxidase. In addition, curcumin significantly decreased myocardial endoplasmic reticulum (ER) stress signaling proteins and improved cardiac function. Furthermore, curcumin significantly decreased the key regulators or inducers of apoptosis. In summary, our results indicate that curcumin has the potential to protect EAM by modulating cardiac oxidative and ER stress-mediated apoptosis, and provides a novel therapeutic strategy for autoimmune myocarditis.

Attenuation of the cardiac inflammatory changes and lipid anomalies by (-)-epigallocatechin-gallate in cigarette smoke-exposed rats.

Cigarette smoking is a major risk factor for cardiovascular diseases and exerts negative effects on the lipid profile. This study was aimed to evaluate the preventive role of (-)-epigallocatechin-gallate (EGCG) on lipid metabolism and cardiac inflammatory changes in cigarette smoke (CS) induced myocardial dysfunction. Adult male albino rats were exposed to side stream CS for a period of 12 weeks and simultaneously administered with EGCG (20 mg/kg b.w./day, p.o.). Exposure to CS showed significant increased (P < 0.05) activities of cardiac injury markers such as, creatine kinase-MB (CKMB) and lactate dehydrogenase (LDH) in serum and subsequent decrease in these enzyme activities in heart. A significant increase (P < 0.05) in serum total cholesterol, fatty acids, phospholipids, and triglycerides were observed in CS exposed rats, along with elevated low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol and decreased high density lipoprotein (HDL) cholesterol. In myocardium, total cholesterol, fatty acids and triglycerides were increased, whereas the phospholipids were found to be decreased. Cardiac lecithin: cholesterol acyl trasferase (LCAT), lipoprotein lipase (LPL), and plasma LCAT activities were significantly decreased (P < 0.05) on CS exposure. Supplementation of EGCG reverted the cardiac injury markers, abnormalities of lipid profile, and lipid-metabolizing enzymes in serum and myocardium. Western blot analysis showed a significant increase in protein expression levels of nuclear factor kappa-B (NF-κB), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) in heart of CS exposed rats. EGCG-treated rats showed a significant decrease in the expression of inflammatory markers. Our data suggest that chronic CS causes lipidemic anomalies and cardiac inflammatory aberrations which may promote cardiac dysfunction and that the antioxidant EGCG exerts a cardio protective effect via reduction of oxidative stress.

Selenium deficiency contributes to the chronic myocarditis in coxsackievirus-infected mice.

Both coxsackievirus B3 (CVB3) infection and selenium (Se) deficiency play a pivotal role in Keshan disease of the heart. The Se deficiency was known to contribute to the CVB3-induced myocarditis in acute and subacute phase of infection. However, its effect on the myocarditis in chronic phase of infection has not been examined yet. To address this question, we kept mice on a Se-replete or Se-deficient diet for 28 days, infected them intraperitoneally with CVB3 and maintaining previous diets, we examined them for next 90 days for several parameters indicative of the infection or disease. We found out that the mice on the Se-deficient diet exhibited a higher mortality, lower serum glutathione peroxidase (GPx) activity, evident histopathological changes indicative of myocarditis, and a higher level of viral RNA in the heart. Summing up, these data suggest that the Se-deficiency creates a chronic myocarditis-prone condition by fostering the active virus replication.

[Effects of Chinese herbal compound for supplementing qi and activating blood circulation on actin, Cx43 expressions and gap junctional intercellular communication functions of myocardial cells in patients with Coxsackie virus B 3 viral myocarditis].

OBJECTIVE: To observe the effect of Chinese herbal compound for supplementing qi and activating blood circulation (CHC) on the gap junctional intercellular communication (GJIC) function of myocardial cells in patients with Coxsackie virus B 3 (CVB3) viral myocarditis. METHODS: Expressions of actin and connexin43 (Cx43) in myocardial cells of patients arranged in three groups (the normal control group, the viral infected group and the CHC treated group) were detected by immunohistochemical method; the fluorescence photobleaching recovery rate of cells was detected by laser scanning confocal microscope. RESULTS: As compared with the viral infected group, the expressions of actin and Cx43 were increased and the GJIC function was improved in the CHC treated group. CONCLUSION: CHC could antagonize viral injury on skeleton protein, and repair the structure of gap junction channel to improve the GJIC function of myocardial cells after being attacked by CVB3.