The Inflammatory Heart Diseases: Causes, Symptoms, and Treatments

Proteomics of the heart

Mass spectrometry-based proteomics is a sophisticated identification tool specializing in portraying protein dynamics at a molecular level. Proteomics provides biologists with a snapshot of context-dependent protein and proteoform expression, structural conformations, dynamic turnover, and protein-protein interactions. Cardiac proteomics can offer a broader and deeper understanding of the molecular mechanisms that underscore cardiovascular disease, and it is foundational to the development of future therapeutic interventions. This review encapsulates the evolution, current technologies, and future perspectives of proteomic-based mass spectrometry as it applies to the study of the heart. Key technological advancements have allowed researchers to study proteomes at a single-cell level and employ robot-assisted automation systems for enhanced sample preparation techniques, and the increase in fidelity of the mass spectrometers has allowed for the unambiguous identification of numerous dynamic posttranslational modifications. Animal models of cardiovascular disease, ranging from early animal experiments to current sophisticated models of heart failure with preserved ejection fraction, have provided the tools to study a challenging organ in the laboratory. Further technological development will pave the way for the implementation of proteomics even closer within the clinical setting, allowing not only scientists but also patients to benefit from an understanding of protein interplay as it relates to cardiac disease physiology.

Investigation into Cardiac Myhc-α 334-352-Specific TCR Transgenic Mice Reveals a Role for Cytotoxic CD4 T Cells in the Development of Cardiac Autoimmunity

Myocarditis is one of the major causes of heart failure in children and young adults and can lead to dilated cardiomyopathy. Lymphocytic myocarditis could result from autoreactive CD4+ and CD8+ T cells, but defining antigen specificity in disease pathogenesis is challenging. To address this issue, we generated T cell receptor (TCR) transgenic (Tg) C57BL/6J mice specific to cardiac myosin heavy chain (Myhc)-α 334-352 and found that Myhc-α-specific TCRs were expressed in both CD4+ and CD8+ T cells. To investigate if the phenotype is more pronounced in a myocarditis-susceptible genetic background, we backcrossed with A/J mice. At the fourth generation of backcrossing, we observed that Tg T cells from naïve mice responded to Myhc-α 334-352, as evaluated by proliferation assay and carboxyfluorescein succinimidyl ester staining. The T cell responses included significant production of mainly pro-inflammatory cytokines, namely interferon (IFN)-γ, interleukin-17, and granulocyte macrophage-colony stimulating factor. While the naïve Tg mice had isolated myocardial lesions, immunization with Myhc-α 334-352 led to mild myocarditis, suggesting that further backcrossing to increase the percentage of A/J genome close to 99.99% might show a more severe disease phenotype. Further investigations led us to note that CD4+ T cells displayed the phenotype of cytotoxic T cells (CTLs) akin to those of conventional CD8+ CTLs, as determined by the expression of CD107a, IFN-γ, granzyme B natural killer cell receptor (NKG)2A, NKG2D, cytotoxic and regulatory T cell molecules, and eomesodermin. Taken together, the transgenic system described in this report may be a helpful tool to distinguish the roles of cytotoxic cardiac antigen-specific CD4+ T cells vs. those of CD8+ T cells in the pathogenesis of myocarditis.

Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases

Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.

2-undecanone protects against fine particles-induced heart inflammation via modulating Nrf2/HO-1 and NF-κB pathways

Exposure to air pollution has been closely associated with some cardiovascular disease. One of the mechanisms of PM_2.5 -mediated heart injury may be to promote inflammation. We aim to investigate whether the main extract of Houttuynia cordata, 2-undecanone, can prevent the inflammation caused by PM_2.5 , and to reveal the underlying mechanisms. The results showed that PM_2.5 increased the expression of certain inflammatory cytokines, and caused oxidative damage in BALB/c mice and H9C2 cells. Supplementation with 2-undecanone attenuated this PM_2.5 -induced inflammatory injury and oxidative damage. Further, we elucidated that the protective effect of 2-undecanone may be associated with NF-κB and Nrf2/HO-1 pathways. The NF-κB pathway was distinctly activated after treated by PM_2.5 , which can be blocked by 2-undecanone, accompanied by increasing Nrf2 and HO-1 levels. To figure out the relationship between NF-κB and Nrf2/HO-1 pathways, we knocked down Nrf2 gene. NF-κB pathway proteins and downstream inflammatory cytokines were significantly increased after treatment with PM_2.5 , while 2-undecanone could decrease expression of these proteins. In conclusion, it is possible that 2-undecanone can induce the expression of the antioxidant enzyme HO-1 by activating Nrf2, thereby reducing NF-κB pathway and inflammatory damage of mouse myocardium caused by PM_2.5 exposure.

The protective effect of rutin against lipopolysaccharide induced acute lung injury in mice based on the pharmacokinetic and pharmacodynamic combination model

Rutin is a flavonoid compound with many pharmacological activities, including antioxidation, anti-inflammation and cardiovascular and cerebrovascular protection. However, there are great limitations in clinical application in view of its poor solubility and slow absorption in vivo. In this study, a pharmacokinetic and pharmacodynomic model was adopted to study the correlation of the pharmacokinetics and pharmacodynomics of rutin in lipopolysaccharide-induced acute lung injury mice. Rutin was intragastrically administered continuously for 5 days at a dose of 200 mg/kg/d, and pharmacokinetic and pharmacodynamic indicators were measured every day after administration, including the blood concentration of rutin, the W/D ratio of lungs, the nitric oxide content and the expression levels of TLR4, TRAF6, IκB and P-IκB proteins. The results indicated that rutin can exert an anti-inflammatory protective effect by improving lung tissue injury, significantly decreasing the synthesis of the inflammatory mediator nitric oxide, and inhibiting the protein expression levels of TLR4, TRAF6 and P-IκB. The absorption of rutin conformed to a one-compartment model with the pharmacokinetic parameters as follows: t_1/2α= 9.76 h, t_1/2β= 19.44 h, T_max= 24.00 h, C_max= 22.65 μg/ml and AUC_(0-t)= 518.58 μg/ml·h. A PK-PD combination model was established to fit the optimal administration time of rutin with a one-compartment-Sigmod Emax model connected to the effect site. Meanwhile,the PK-PD combination model was a better approach for evaluating the relationships between the five pharmacodynamic indicators and the pharmacokinetic characteristics of rutin. The correlation between the pharmacokinetics and pharmacodynamics of rutin was quantitatively analysed to provide a theoretical basis for the research and development of new anti-inflammatory drugs in clinical practice.

Heart Infection Prognosis Analysis by Two-dimensional Spot Tracking Imaging

Cardiovascular death is one of the leading causes worldwide; an accurate identification followed by diagnosing the cardiovascular disease increases the chance of a better recovery. Among different demonstrated strategies, imaging on cardiac infections yields a visible result and highly reliable compared to other analytical methods. Two-dimensional spot tracking imaging is the emerging new technology that has been used to study the function and structure of the heart and test the deformation and movement of the myocardium. Particularly, it helps to capture the images of each segment in different directions of myocardial strain values, such as valves of radial strain, longitudinal strain, and circumferential strain. In this overview, we discussed the imaging of infections in the heart by using the two-dimensional spot tracking.

Triggers of Inflammatory Heart Disease

Inflammatory heart disease (IHD) is a group of diseases that includes pericarditis, myocarditis, and endocarditis. Although males appear to be more commonly affected than females, IHD can be seen in any age group. While the disease can be self-limiting leading to full recovery, affected individuals can develop chronic disease, suggesting that identification of primary triggers is critical for successful therapies. Adding to this complexity, however, is the fact that IHD can be triggered by a variety of infectious and non-infectious causes that can also occur as secondary events to primary insults. In this review, we discuss the immunological insights into the development of IHD as well as a mechanistic understanding of the disease process in animal models.

Improvement of insulin signalling rescues inflammatory cardiac dysfunction

Inflammation resulting from virus infection is the cause of myocarditis; however, the precise mechanism by which inflammation induces cardiac dysfunction is still unclear. In this study, we investigated the contribution of insulin signalling to inflammatory cardiac dysfunction induced by the activation of signalling by NF-κB, a major transcriptional factor regulating inflammation. We generated mice constitutively overexpressing kinase-active IKK-β, an essential kinase for NF-κB activation, in cardiomyocytes (KA mice). KA mice demonstrated poor survival and significant cardiac dysfunction with remarkable dilation. Histologically, KA hearts revealed increased cardiac apoptosis and fibrosis and the enhanced recruitment of immune cells. By molecular analysis, we observed the increased phosphorylation of IRS-1, indicating the suppression of insulin signalling in KA hearts. To evaluate the contribution of insulin signalling to cardiac dysfunction in KA hearts, we generated mice with cardiac-specific suppression of phosphatase and tensin homologue 10 (PTEN), a negative regulator of insulin signalling, in the KA mouse background (KA-PTEN). The suppression of PTEN successfully improved insulin signalling in KA-PTEN hearts, and interestingly, KA-PTEN mice showed significantly improved cardiac function and survival. These results indicated that impaired insulin signalling underlies the mechanism involved in inflammation-induced cardiac dysfunction, which suggests that it may be a target for the treatment of myocarditis.

Ferulic Acid Supplementation Improves Lipid Profiles, Oxidative Stress, and Inflammatory Status in Hyperlipidemic Subjects: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Ferulic acid is the most abundant phenolic compound found in vegetables and cereal grains. In vitro and animal studies have shown ferulic acid has anti-hyperlipidemic, anti-oxidative, and anti-inflammatory effects. The objective of this study is to investigate the effects of ferulic acid supplementation on lipid profiles, oxidative stress, and inflammatory status in hyperlipidemia. The study design is a randomized, double-blind, placebo-controlled trial. Subjects with hyperlipidemia were randomly divided into two groups. The treatment group (n = 24) was given ferulic acid (1000 mg daily) and the control group (n = 24) was provided with a placebo for six weeks. Lipid profiles, biomarkers of oxidative stress and inflammation were assessed before and after the intervention. Ferulic acid supplementation demonstrated a statistically significant decrease in total cholesterol (8.1%; p = 0.001), LDL-C (9.3%; p < 0.001), triglyceride (12.1%; p = 0.049), and increased HDL-C (4.3%; p = 0.045) compared with the placebo. Ferulic acid also significantly decreased the oxidative stress biomarker, MDA (24.5%; p < 0.001). Moreover, oxidized LDL-C was significantly decreased in the ferulic acid group (7.1%; p = 0.002) compared with the placebo group. In addition, ferulic acid supplementation demonstrated a statistically significant reduction in the inflammatory markers hs-CRP (32.66%; p < 0.001) and TNF-α (13.06%; p < 0.001). These data indicate ferulic acid supplementation can improve lipid profiles and oxidative stress, oxidized LDL-C, and inflammation in hyperlipidemic subjects. Therefore, ferulic acid has the potential to reduce cardiovascular disease risk factors.