Non-coding RNAs in cardiac inflammation: key drivers in the pathophysiology of heart failure

Cardiomyopathies: The Role of Non-Coding RNAs

Cardiomyopathies are the structural and functional disorders of the myocardium. Etiopathogenesis is complex and involves an interplay of genetic, environmental, and lifestyle factors eventually leading to myocardial abnormalities. It is known that non-coding (Nc) RNAs, including micro (mi)-RNAs and long non-coding (lnc) RNAs, play a crucial role in regulating gene expression. Several studies have explored the role of miRNAs in the development of various pathologies, including heart diseases. In this review, we analyzed various patterns of ncRNAs expressed in the most common cardiomyopathies: dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic cardiomyopathy. Understanding the role of different ncRNAs implicated in cardiomyopathic processes may contribute to the identification of potential therapeutic targets and novel risk stratification models based on gene expression. The analysis of ncRNAs may also be helpful to unveil the molecular mechanisms subtended to these diseases.

Macrophage-based therapeutic approaches for cardiovascular diseases

Despite the advances in treatment options, cardiovascular disease (CVDs) remains the leading cause of death over the world. Chronic inflammatory response and irreversible fibrosis are the main underlying pathophysiological causes of progression of CVDs. In recent decades, cardiac macrophages have been recognized as main regulatory players in the development of these complex pathophysiological conditions. Numerous approaches aimed at macrophages have been devised, leading to novel prospects for therapeutic interventions. Our review covers the advancements in macrophage-centric treatment plans for various pathologic conditions and examines the potential consequences and obstacles of employing macrophage-targeted techniques in cardiac diseases.

Polo-like kinase 1 promotes sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is the main cause of mortality in sepsis. In this study, we identified Polo-like kinase 1 (Plk-1) is a promoter of SIMD. Plk-1 expression was increased in lipopolysaccharide (LPS)-treated mouse hearts and neonatal rat cardiomyocytes (NRCMs). Inhibition of Plk-1 either by heterozygous deletion of Plk-1 or Plk-1 inhibitor BI 6727 alleviated LPS-induced myocardial injury, inflammation, cardiac dysfunction, and thereby improved the survival of LPS-treated mice. Plk-1 was identified as a kinase of inhibitor of kappa B kinase alpha (IKKα). Plk-1 inhibition impeded NF-κB signal pathway activation in LPS-treated mouse hearts and NRCMs. Augmented Plk-1 is thus essential for the development of SIMD and is a druggable target for SIMD.

ETS2 promotes cardiomyocyte apoptosis and autophagy in heart failure by regulating lncRNA TUG1/miR-129-5p/ATG7 axis

Heart failure (HF) is a chronic disease in which the heart is unable to provide enough blood and oxygen to the peripheral tissues. Cardiomyocyte apoptosis and autophagy have been linked to HF progression. However, the underlying mechanism of HF is unknown. In this study, H₂ O₂ -treated AC16 cells were used as a cell model of HF. The mRNA and protein levels of related genes were examined using RT-qPCR and western blot. Cell viability and apoptosis were assessed using CCK-8 and flow cytometry, respectively. The interactions between ETS2, TUG1, miR-129-5p, and ATG7 were validated by luciferase activity, ChIP, and RNA-Binding protein Immunoprecipitation assays. According to our findings, H₂ O₂ stimulation increased the expression of ETS2, TUG1, and ATG7 while decreasing the expression of miR-129-5p in AC16 cells. Furthermore, H₂ O₂ stimulation induced cardiomyocyte apoptosis and autophagy, which were reversed by ETS2 depletion, TUG1 silencing, or miR-129-5p upregulation. Mechanistically, ETS2 promoted TUG1 expression by binding to the TUG1 promoter, and TUG1 sponged miR-129-5p to increase ATG7 expression. Furthermore, TUG1 overexpression reversed ETS2 knockdown-mediated inhibition of cardiomyocyte apoptosis and autophagy and miR-129-5p inhibition abolished TUG1 depletion-mediated suppression of cardiomyocyte apoptosis and autophagy in H₂ O₂ -induced AC16 cells. As presumed, ATG7 overexpression reversed miR-129-5p mimics-mediated repression of cardiomyocyte apoptosis and autophagy in H₂ O₂ -induced AC16 cells. Finally, ETS2 silencing reduced cardiomyocyte apoptosis and autophagy to slow HF progression by targeting the ETS2/TUG1/miR-129-5p/ATG7 axis, which may provide new therapeutic targets for HF treatment.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

The Role of MicroRNAs in Dilated Cardiomyopathy: New Insights for an Old Entity

Dilated cardiomyopathy (DCM) is a clinical diagnosis characterized by left ventricular or biventricular dilation and systolic dysfunction. In most cases, DCM is progressive, leading to heart failure (HF) and death. This cardiomyopathy has been considered a common and final phenotype of several entities. DCM occurs when cellular pathways fail to maintain the pumping function. The etiology of this disease encompasses several factors, such as ischemia, infection, autoimmunity, drugs or genetic susceptibility. Although the prognosis has improved in the last few years due to red flag clinical follow-up, early familial diagnosis and ongoing optimization of treatment, due to its heterogeneity, there are no targeted therapies available for DCM based on each etiology. Therefore, a better understanding of the mechanisms underlying the pathophysiology of DCM will provide novel therapeutic strategies against this cardiac disease and their different triggers. MicroRNAs (miRNAs) are a group of small noncoding RNAs that play key roles in post-transcriptional gene silencing by targeting mRNAs for translational repression or, to a lesser extent, degradation. A growing number of studies have demonstrated critical functions of miRNAs in cardiovascular diseases (CVDs), including DCM, by regulating mechanisms that contribute to the progression of the disease. Herein, we summarize the role of miRNAs in inflammation, endoplasmic reticulum (ER) stress, oxidative stress, mitochondrial dysfunction, autophagy, cardiomyocyte apoptosis and fibrosis, exclusively in the context of DCM.