Dapagliflozin Alleviates Myocardial Inflammation by Regulating the Macrophage Polarization and Stat3-related Pathways in Coxsackie Virus B3-induced Acute Viral Myocarditis

Viral myocarditis (VMC), which is most prevalently caused by Coxsackievirus B3 (CVB3) infection, is a serious clinical condition characterized by cardiac inflammation. Dapagliflozin, a kind of sodium glucose co-transporters 2(SGLT-2) inhibitor, exhibited protective effects on plenty of inflammatory diseases, while its effect on viral myocarditis has not been studied. Recently we found the protective effect of dapagliflozin on VMC. After CVB3 infection, dapagliflozin were given orally to Balb/c male mice for 8 days and then the severity of myocarditis was assessed. Our results indicated that dapagliflozin significantly alleviated the severity of viral myocarditis, elevated the survival rate, and ameliorated cardiac function. Besides, dapagliflozin can decrease the level of proinflammatory cytokines included IL-1β, IL-6, TNF-α. Furthermore, dapagliflozin can inhibit macrophages differentiate to classically activated macrophages (M1) in cardiac tissue and activate the Stat3 signal pathway which is reported to promote polarization of the alternatively activated macrophage (M2). In conclusion, our study demonstrates that dapagliflozin alleviates myocardial inflammation by regulating the macrophage polarization and Stat3-related pathways in coxsackie virus B3-induced acute viral myocarditis.

Effects of Nano-α-Linolenic Acid and miR-146 on Mice with Viral Myocarditis

Micro RNA-146 (miR-146) is involved in mediating many innate and adaptive immune and inflammatory responses in the body. It is associated with a variety of systemic inflammation or autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and type 2 diabetes. In recent years, microRNAs (miRNAs) and nanotechnology have become research hotspots in cardiovascular pathology. The close relationship between host miRNAs and coxsackie virus B3 has gradually been discovered by scientists, which may provide new directions for the treatment and prevention of viral myocarditis. At the same time, recent studies have also found that nano-α-linolenic acid and its metabolites can inhibit the production of inflammatory cytokines such as TNF-α and IL-17; At the same time, they also have anti-lipid peroxidation effects. Therefore, in order to further explore the role of miR-146 and nano-α-linolenic acid in the occurrence and development of viral myocarditis, in this study, a mouse model of viral myocarditis was used to establish a VMC mouse model using coxsackie virus B3. Intervention with different doses of nano-α-linolenic acid, the control group was injected with the same amount of sodium chloride buffer, and the changes in cardiac function and inflammation indexes were compared to evaluate the role in the pathogenesis of viral myocarditis. The results showed that this study suggested that serum miR-146 concentration in viral myocarditis mice is increased and is positively correlated with serum IL-17 and TNF-α concentrations. This suggest that miR-146 in the circulation may be involved in the pathogenesis of viral myocarditis through IL-17 and TNF-α, providing a theoretical basis for the role of miR-146 in viral myocarditis, but its specific mechanism of action needs to be further studied. At the same time, the research in this experiment showed that nano-α-linolenic acid significantly improves the survival rate of CVB3 infected mice and reduces myocardial damage. And with the increase of the dosage of nano-α-linolenic acid, the effect is more significant, showing a significant dose-effect relationship.

Advancement of Mechanisms of Coxsackie Virus B3-Induced Myocarditis Pathogenesis and the Potential Therapeutic Targets

Viral myocarditis is a cardiac disease caused by Group B Coxsackie virus of Enterovirus genus in the Picorna viridae family. It causes heart failure in children, young and adults. Ten Percent (10%) of acute heart failure and 12% of sudden deaths in young and adults who are less than 40 years is due to this viral myocarditis. If treatment action is not taken earlier, the viral disease can develop into chronic myocarditis and Dilated Cardiomyopathy which lead to congestive heart failure. And these eventually result in a reduced cardiac function which finally brings the victim to death. The only treatment option of the disease is heart transplantation once the acute stage of disease develops to chronic and Dilated Cardiomyopathy. Currently, there is a limitation in daily clinical treatments and even some available treatment options are ineffective. Therefore, focusing on search for treatment options through investigation is imperative. Recent studies have reported that biological molecules show a promising role. But their mechanism of pathogenesis is still unclear. A detailed study on identifying the role of biological molecules involved in Coxsackie B3 virus induced myocarditis and their mechanisms of pathogenesis; compiling and disseminating the findings of the investigation to the scientific communities contribute one step forward to the solution. Therefore, this review is aimed at compiling information from findings of current studies on the potential therapeutic role of micro RNA, cytokines and chemokines on the mechanism of pathogenesis of Coxsackie virus B3- induced myocarditis to give brief information for scholars to conduct a detailed study in the area.

Tanshinone IIA Ameliorate Coxsackie Virus B3-Induced Viral Myocarditis through the Inhibition of Inflammation and Modulation T Helper 1/T Helper 2 Balance in Mice

To investigate the effect of Tanshinone IIA (TSA) on viral myocarditis (VMC). VMC animal model was established using BALB/c mice by intraperitoneally injecting Coxsackie virus B3 (CVB3). The mice were randomly divided into control group, model group, and TSA group. We detected the survival rate, the heart weight to body weight (HW/BW) ratio and hemodynamic and cardiac function parameters. The pathological features of VMC were measured through H&E staining. The expression of serum enzyme, inflammatory cytokines, and T helper (Th)1/Th2 markers was also investigated. TSA remarkably alleviated CVB3-caused myocardial injury, decreased the HW/BW ratio, and improved survival rate. TSA obviously improved hemodynamic parameters and reversed the damage to the heart pump function. Furthermore, the serum levels of lactate dehydrogenase, creatine kinase, and Th1 cytokines in the TSA group were significantly lower than those in the VMC group, and TSA treatment significantly improved the pathological condition. The interferon-gamma (IFN-γ) and interleukin-2 (IL-2) levels in VMC model group was higher than control group, and lower levels of IL-4 and IL-10 were identified. However, TSA treatment elevated IL-4 and IL-10 levels and decreased IFN-γ and IL-2 levels. TSA could effectively protect the myocardium against CVB3-induced myocarditis by the inhibition of inflammation and modulation Th1/Th2 balance in mice.