Interleukin-1β levels predict long-term mortality and need for heart transplantation in ambulatory patients affected by idiopathic dilated cardiomyopathy

The Role of Inflammasomes in Heart Failure

Heart failure (HF) poses a significant world health challenge due to the increase in the aging population and advancements in cardiac care. In the pathophysiology of HF, the inflammasome has been correlated with the development, progression, and complications of HF disease. Discovering biomarkers linked to inflammasomes enhances understanding of HF diagnosis and prognosis. Directing inflammasome signaling emerges as an innovative therapeutic strategy for managing HF. The present review aims to delve into this inflammatory cascade, understanding its role in the development of HF, its potential role as biomarker, as well as the prospects of modulating inflammasomes as a therapeutic approach for HF.

Pathogenic pathways and therapeutic targets of inflammation in heart diseases: A focus on Interleukin-1

BACKGROUND

An exuberant and dysregulated inflammatory response contributes to the development and progression of cardiovascular diseases (CVDs).

METHODS

This narrative review includes original articles and reviews published over the past 20 years and found through PubMed. The following search terms (or combination of terms) were considered: "acute pericarditis," "recurrent pericarditis," "myocarditis," "cardiac sarcoidosis," "atherosclerosis," "acute myocardial infarction," "inflammation," "NLRP3 inflammasome," "Interleukin-1" and "treatment."

RESULTS

Recent evidence supports the role of inflammation across a wide spectrum of CVDs including myocarditis, pericarditis, inflammatory cardiomyopathies (i.e. cardiac sarcoidosis) as well as atherosclerotic CVD and heart failure. Interleukins (ILs) are the signalling mediators of the inflammatory response. The NACHT, leucine-rich repeat and pyrin-domain containing protein 3 (NLRP3) inflammasome play a key role in producing IL-1β, the prototypical pro-inflammatory cytokine involved in CVDs. Other pro-inflammatory cytokines (e.g. tumour necrosis factor) have been implicated in cardiac sarcoidosis. As a proof of this, IL-1 blockade has been proven efficacious in pericarditis and chronic coronary syndrome.

CONCLUSION

Tailored strategies aiming at quenching the inflammatory response have emerged as promising to treat CVDs. In this review article, we summarize recent evidence regarding the role of inflammation across a broad spectrum of CVDs. We also review novel evidence regarding targeted therapeutic strategies.

Dilated cardiomyopathy and chronic cardiac inflammation: Pathogenesis, diagnosis and therapy

Dilated cardiomyopathy (DCM) is typically defined by left ventricular dilation and systolic dysfunction in the absence of a clear precipitant. Idiopathic disease is common; up to 50% of patients with DCM have no cause found despite imaging, genetic and biopsy assessments. Treatment remains focused on managing symptoms, reducing the risk of sudden cardiac death and ameliorating the structural and electrical complications of disease progression. In the absence of aetiology-specific treatments, the condition remains associated with a poor prognosis; mortality is approximately 40% at 10 years. The role of immune-mediated inflammatory injury in the development and progression of DCM was first proposed over 30 years ago. Despite the subsequent failures of three large clinical trials of immunosuppressive treatment (ATTACH, RENEWAL and the Myocarditis Treatment Trial), evidence for an abnormal adaptive immune response in DCM remains significant. In this review, we summarise and discuss available evidence supporting immune dysfunction in DCM, with a specific focus on cellular immunity. We also highlight current clinical and experimental treatments. We propose that the success of future immunosuppressive treatment trials in DCM will be dependent on the deep immunophenotyping of patients, to identify those with active inflammation and/or an abnormal immune response who are most likely to respond to therapy.

Biomakers in Chronic Chagas Cardiomyopathy

The primary objective was to observe the relationship between serum levels of BNP, Ca-125, C-reactive protein and uric acid as prognostic and functional markers in patients with chronic Chagas cardiomyopathy (CCC). Circulating levels of cytokines: IL-1β, TNFα, IL-10, IL6, IL-8 and IL-12 were determined and investigated regarding their association with hemodynamic parameters, clinical signs of heart failure and outcome. Chagas is still a neglected disease that affects numerous individuals, many of them in their most productive years. CCC with left ventricular dysfunction is the most severe presentation of Chagas Disease. BNP is a well-recognized prognostic and clinical biomarker, not only in chronic heart failure patients but also in patients with CCC. Previous studies have shown Ca-125, C-reactive protein, and uric acid to be potentially good prognostic markers in heart failure (HF). Fifty patients with left ventricular fraction less (LVEF) than 55% were selected and followed for a mean period of 18 ± 8.3 months. Patient’s mean age was 43.42 ± 10.3 years (32 male), their BNP was 293 (160–530) pg/mL, Ca-125 8.5 (5.5–16.75) U/mL, uric acid 6.2 ± 2 mg/dL, and C- reactive protein 4.5 (4.5–7.3) mg/L. Patients who had LVEF less than 35% had higher BNP (p = 0.0023), Ca-125 (p = 0.027) and uric acid (p = 0.01) serum levels. Patients who died also showed higher BNP (p = 0.01), uric acid (p = 0.05) and a trend towards higher Ca-125 serum levels (p = 0.056). All markers: BNP, Ca-125, uric acid and C-reactive had good predictability of death in Cox-regression univariate analysis, however, not on the final multivariate model. Of the inflammatory cytokines, IL-8 and IL-12 showed a relation to LVEF of less than 35%. IL-12 was related to adverse cardiovascular events and non-survival. IL-1β was a good predictor of mortality in the final Cox regression model. Determination of Ca-125, uric acid levels and C-reactive protein may add useful clinical and prognostic information and may help clinical decision making for patients with CCC.

Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results

Inflammation has emerged as an important contributor to heart failure (HF) development and progression. Current research data highlight the diversity of immune cells, proteins, and signaling pathways involved in the pathogenesis and perpetuation of heart failure. Chronic inflammation is a major cardiovascular risk factor. Proinflammatory signaling molecules in HF initiate vicious cycles altering mitochondrial function and perturbing calcium homeostasis, therefore affecting myocardial contractility. Specific anti-inflammatory treatment represents a novel approach to prevent and slow HF progression. This review provides an update on the putative roles of inflammatory mediators involved in heart failure (tumor necrosis factor-alpha; interleukin 1, 6, 17, 18, 33) and currently available biological and non-biological therapy options targeting the aforementioned mediators and signaling pathways. We also highlight new treatment approaches based on the latest clinical and experimental research.

Altered mRNA Expression of Interleukin-1 Receptors in Myocardial Tissue of Patients with Left Ventricular Assist Device Support

Serum levels of cytokines interleukin 1 beta ( IL-1β) and interleukin 33 (IL-33) are highly abnormal in heart failure and remain elevated after mechanical circulatory support (MCS). However, local cytokine signaling induction remains elusive. Left (LV) and right ventricular (RV) myocardial tissue specimens of end-stage heart failure (HF) patients without (n = 24) and with MCS (n = 39; 594 ± 57 days) were analyzed for cytokine mRNA expression level of IL-1B, interleukin 1 receptor 1/2 (IL-1R1/2), interleukin 1 receptor-like 1 (IL-1RL1), IL-33 and interleukin-1 receptor accessory protein (IL-1RaP). MCS patients showed significantly elevated IL-1B expression levels (LV: 2.0 fold, p = 0.0058; RV: 3.3 fold, p < 0.0001). Moreover, IL-1R1, IL-1RaP and IL-33 expression levels strongly correlated with each other. IL-1RL1 and IL-1R2 expression levels were significantly higher in RV myocardial tissue (RV/LV ratio IL-1R2 HF: 4.400 ± 1.359; MCS: 4.657 ± 0.655; IL-1RL1 HF: 3.697 ± 0.876; MCS: 4.529 ± 0.5839). In addition, IL1-RaP and IL-33 RV expression levels were significantly elevated in MCS. Furthermore, IL-33 expression correlates with C-reactive protein (CRP) plasma levels in HF, but not in MCS patients. Increased expression of IL-1B and altered correlation patterns of IL-1 receptors indicate enhanced IL-1β signaling in MCS patients. Correlation of IL-1 receptor expression with IL-33 may hint towards a link between both pathways. Moreover, diverging expression in LV and RV suggests specific regulation of local cytokine signaling.

The Diagnostic and Therapeutic Value of Multimarker Analysis in Heart Failure. An Approach to Biomarker-Targeted Therapy

Background: Heart failure is a pathophysiological state, which is still associated with high morbidity and mortality despite established therapies. Diverse well-known biomarkers fail to assess the variety of individual pathophysiology in the context of heart failure.

Methods: An analysis of prospective, multimarker-specific therapeutic approaches to heart failure based on studies in current literature was performed. A total of 159 screened publications in the field of biomarkers in heart failure were hand-selected and found to be eligible for this study by a team of experts.

Results: Established biomarkers of the inflammatory axis, matrix remodeling, fibrosis and oxidative stress axis, as well as potential therapeutic interventions were investigated. Interaction with end organs, such as cardio-hepatic, cardio-renal and cardio-gastrointestinal interactions show the complexity of the syndrome and could be of further therapeutic value. MicroRNAs are involved in a wide variety of physiologic and pathophysiologic processes in heart failure and could be useful in diagnostic as well as therapeutic setting.

Conclusion: Based on our analysis by a biomarker-driven approach in heart failure therapy, patients could be treated more specifically in long term with a consideration of different aspects of heart failure. New studies evaluating a multimarker – based therapeutic approach could lead in a decrease in the morbidity and mortality of heart failure patients.

Ischemic dilated cardiomyopathy pathophysiology through microRNA-16-5p

INTRODUCTION AND OBJECTIVES

The expression levels of microRNA-16-5p (miR-16) are upregulated in ischemic cardiomyopathy and in animal models of ischemic dilated cardiomyopathy (iDCM), inducing myocardial apoptosis. We investigated the role of miR-16 in the adaptive cellular response associated with endoplasmic reticulum (ER) stress and autophagy in the apoptotic iDCM environment.

METHODS

We quantified the miR-16 plasma levels of 168 participants-76 controls, 60 iDCM patients, and 32 familial DCM patients with the pathogenic variant of BAG3-by quantitative real-time polymerase chain reaction and correlated the levels with patient variables. The effects of intracellular miR-16 overexpression were analyzed in a human cardiac cell line. Apoptosis and cell viability were measured, as well as the levels of markers associated with ER stress, cardiac injury, and autophagy.

RESULTS

Plasma miR-16 levels were upregulated in iDCM patients (P=.039). A multivariate logistic regression model determined the association of miR-16 with iDCM clinical variables (P <.001). In vitro, miR-16 overexpression increased apoptosis (P=.02) and reduced cell viability (P=.008). Furthermore, it induced proapoptotic components of ER stress, based on upregulation of the PERK/CHOP pathway. However, we observed augmentation of autophagic flux (P <.001) without lysosomal blockade by miR-16 as a possible cytoprotective mechanism.

CONCLUSIONS

MiR-16 is specifically associated with iDCM. In an ischemic setting, miR-16 activates ER stress and promotes inflammation followed by autophagy in human cardiac cells. Thus, autophagy may be an attempt to maintain cellular homeostasis in response to misfolded/aggregated proteins related to ER stress, prior to apoptosis.

Autophagy and Inflammasome Activation in Dilated Cardiomyopathy

Background: The clinical outcome of patients affected by dilated cardiomyopathy (DCM) is heterogeneous, since its pathophysiology is only partially understood. Interleukin 1β levels could predict the mortality and necessity of cardiac transplantation of DCM patients. Objective: To investigate mechanisms triggering sterile inflammation in dilated cardiomyopathy (DCM). Methods: Hearts explanted from 62 DCM patients were compared with 30 controls, employing immunohistochemistry, cellular and molecular biology, as well as metabolomics studies. Results: Although misfolded protein accumulation and aggresome formation characterize DCM hearts, aggresomes failed to trigger the autophagy lysosomal pathway (ALP), with consequent accumulation of both p62^SQSTM1 and dysfunctional mitochondria. In line, DCM hearts are characterized by accumulation of lipoperoxidation products and activation of both redox responsive pathways and inflammasome. Consistently with the fact that mTOR signaling may impair ALP, we observed, an increase in DCM activation, together with a reduction in the nuclear localization of Transcription Factor EB -TFEB- (a master regulator of lysosomal biogenesis). These alterations were coupled with metabolomic alterations, including accumulation of branched chain amino acids (BCAAs), known mTOR activators. Consistently, reduced levels of PP2Cm, a phosphatase that regulates the key catabolic step of BCAAs, coupled with increased levels of miR-22, a regulator of PP2Cm levels that triggers senescence, characterize DCM hearts. The same molecular defects were present in clinically relevant cells isolated from DCM hearts, but they could be reverted by downregulating miR-22. Conclusion: We identified, in human DCM, a complex series of events whose key players are miR-22, PP2Cm, BCAA, mTOR, and ALP, linking loss of proteostasis with inflammasome activation. These potential therapeutic targets deserve to be further investigated.

The circulating level of interleukins 6 and 18 in ischemic and idiopathic dilated cardiomyopathy

Introduction: By aging population, the heart failure and its life-threatening complications have become an enormous issue in public health. Regarding the inflammation as a major contributing pathological factor, the determination of most important inflammatory targets for immunomodulation is a problematic puzzle in the treatment of heart failure patients and the inflammatory pathways primarily involved in different underlying conditions contributing to heart failure can be an area which is worthy of focused research. Considering the dilated cardiomyopathy (DCM) as a relatively high-incident disease leading to heart failure, the aim of this study is to determine the difference in the expression level of interleukin (IL)-6 and IL-18 in patients with ischemic and idiopathic DCM. Methods: 39 non-diabetic patients with ischemic and 37 ones with idiopathic DCM were enrolled in the study. 48 healthy individuals were also considered as control group. For quantitative determination of the mRNA expression level of IL-6 and IL-18 genes, an in-house- SYBR Green real-time PCR was used and Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was considered as internal control gene. The left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) was calculated by 2D echocardiographic assessment. Data were finally analyzed via SPSS statistical software version 19.0 using independent t test and 2-∆∆Ct method and P<0.05 were considered statistically significant. Results: The IL-6 was significantly higher expressed in patients with ischemic and idiopathic DCM than in healthy controls (274.3 and 168.8 times, respectively, both P values <0.001). The same higher expression of IL-18 was observed in ischemic DCM (48.5 times) and idiopathic DCM (45.2 times) compared with healthy individuals (both P values <0.001). Conclusion: Both ischemic and idiopathic DCM associates with IL-6 and IL-18 overexpression. However, no significant difference was observed between these two subtypes of DCM in either interleukin expression level. There is certainly need to further studies for evaluating the uniformity of results and also assessing other molecules in determining their roles in pathophysiology and probable utility for management.

Role of cytokines and inflammation in heart function during health and disease

By virtue of their actions on NF-κB, an inflammatory nuclear transcription factor, various cytokines have been documented to play important regulatory roles in determining cardiac function under both physiological and pathophysiological conditions. Several cytokines including TNF-α, TGF-β, and different interleukins such as IL-1 IL-4, IL-6, IL-8, and IL-18 are involved in the development of various inflammatory cardiac pathologies, namely ischemic heart disease, myocardial infarction, heart failure, and cardiomyopathies. In ischemia-related pathologies, most of the cytokines are released into the circulation and serve as biological markers of inflammation. Furthermore, there is an evidence of their direct role in the pathogenesis of ischemic injury, suggesting cytokines as potential targets for the development of some anti-ischemic therapies. On the other hand, certain cytokines such as IL-2, IL-4, IL-6, IL-8, and IL-10 are involved in the post-ischemic tissue repair and thus are considered to exert beneficial effects on cardiac function. Conflicting reports regarding the role of some cytokines in inducing cardiac dysfunction in heart failure and different types of cardiomyopathies seem to be due to differences in the nature, duration, and degree of heart disease as well as the concentrations of some cytokines in the circulation. In spite of extensive research work in this field of investigation, no satisfactory anti-cytokine therapy for improving cardiac function in any type of heart disease is available in the literature.

The pleiotropic association between IL-10 levels and CVD prognosis: Evidence from a meta-analysis

We examined the precise association between IL-10 levels and cardiovascular disease (CVD) prognosis and explored the pleiotropic role of IL-10 in different cardiac pathologies. We performed a meta-analysis of cross-sectional and longitudinal studies investigating IL-10 levels. Meta-regression analyses were used to determine the cause of the discrepancies. To assess publication bias, funnel plots were constructed, and Egger's tests were performed. Data from the GSE58015 dataset were used to investigate the levels of IL-10 under certain conditions. Because of substantial heterogeneity in the data used to compare the IL-10 levels between patients with CVD and healthy people, we could not determine the differences between the healthy controls and patients with ischemic or nonischemic pathologies (p > 0.05). The analysis of the association between IL-10 levels and CVD prognosis indicated that higher IL-10 levels were significantly associated with a poor prognosis in patients with nonischemic pathologies (HR = 1.10, 95% CI = 1.00-1.20, p = 0.043) but differentially associated with the prognosis of patients with ischemic pathologies based on the sampling time point (before percutaneous coronary intervention (PCI): HR = 4.90, 95% CI = 1.24-19.30, p < 0.001; after PCI: HR = 0.57, 95% CI = 0.43-0.75, p = 0.023). The meta-regression analysis showed that the pooled HR of the IL-10 levels was positively correlated with the IL-10/IL-6 ratio (β = 0.644, p = 0.024). The funnel plots and Egger's tests revealed no statistically significant bias in our meta-analysis (p > 0.1). Furthermore, our data mining analysis supported our findings. Our analysis showed that IL-10 levels may be pleiotropically associated with the CVD prognosis possibly based on the type of pathology, disease stage and levels of other proinflammatory factors, such as IL-6.

Immunity, Inflammation, and Oxidative Stress in Heart Failure: Emerging Molecular Targets

PURPOSE

Heart failure (HF) remains a major cause of morbidity and mortality worldwide. Although various therapies developed over the last two decades have shown improved long term outcomes in patients with established HF, there has been little progress in preventing the adverse cardiac remodeling that initiates HF. To fill the gap in treatment, current research efforts are focused on understanding novel mechanisms and signaling pathways. Immune activation, inflammation, oxidative stress, alterations in mitochondrial bioenergetics, and autophagy have been postulated as important pathophysiological events in this process. An improved understanding of these complex processes could facilitate a therapeutic shift toward molecular targets that can potentially alter the course of HF.

METHODS

In this review, we address the role of immunity, inflammation, and oxidative stress as well as other novel emerging concepts in the pathophysiology of HF that may have therapeutic implications.

CONCLUSION

Based on the experimental and clinical studies presented here, we anticipate that a better understanding of the pathophysiology of HF will open the door for new therapeutic targets. A one-size-fits-all approach may not be appropriate for all patients with HF, and further clinical trials utilizing molecular targeting in HF may result in improved outcomes.

The Inflammasomes in Cardiovascular Disease

Cardiovascular disease (CVD) is the number one cause of death worldwide. The pathogenesis of various disease entities that comprise the area of CVD is complex and multifactorial. Inflammation serves a central role in these complex aetiologies. The inflammasomes are intracellular protein complexes activated by danger-associated molecular patterns (DAMPs) present in CVD such as atherosclerosis and myocardial infarction (MI). After a two-step process of priming and activation, inflammasomes are responsible for the formation of pro-inflammatory cytokines interleukin-1β and interleukin-18, inducing a signal transduction cascade resulting in a strong immune response that culminates in disease progression. In the past few years, increased interest has been raised regarding the inflammasomes in CVD. Inflammasome activation is thought to be involved in the pathogenesis of various disease entities such as atherosclerosis, MI and heart failure (HF). Interference with inflammasome-mediated signalling could reduce inflammation and attenuate the severity of disease. In this chapter we provide an overview of the current literature available on the role of inflammasome inhibition as a therapeutic intervention and the possible clinical implications for CVD.