ASC Methylation and Interleukin-1β Are Associated with Aerobic Capacity in Heart Failure

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.

The Effects of Exercise on Telomere Length in Persons With Heart Failure

BACKGROUND

Telomere length is reduced in persons with heart failure (HF). Inflammation is a putative mechanism contributing to telomere shortening. Although physical activity is known to increase telomere length, its effects in HF are unknown.

OBJECTIVE

The aim of this study was to examine the effects of exercise on telomere length and its relationship with interleukin (IL)-1β in persons with HF.

METHODS

This secondary analysis of a 3-month home-based aerobic exercise intervention measured total telomere length and IL-1β levels in persons with HF (69% with reduced ejection fraction).

RESULTS

Total telomere length increased and plasma IL-1β levels decreased in the exercise group from baseline to 3 months. Total telomere length was negatively associated with IL-1β at baseline (r = -0.441 P = .001).

CONCLUSIONS

The association between telomere length and IL-1β suggests a relationship between inflammation and cellular aging. Moderate-intensity exercise may help maintain cellular functions. Further research is needed to examine the effects on outcomes in persons with HF.

NLRP3 inflammasome as a novel therapeutic target for heart failure

Heart failure (HF) is a leading cause of mortality worldwide. The pathogenesis of HF is complex and has not yet been fully elucidated, which has slowed drug development and long-term treatments. Inflammasome-mediated responses occur during the progression of HF. It has been reported that energy metabolism and metabolites of intestinal flora are also involved in the process of HF, and they interact with each other to promote the progression of HF. NLR family pyrin domain containing 3 (NLRP3) inflammasome may be a key target in the relationship between inflammation-mediated energy metabolism and metabolites of intestinal flora. Elucidating the relationship among the above three factors may help to identify new molecular targets for the prevention and treatment of HF and ultimately affect the course of HF. In this study, we systematically summarize evidence regarding the relationship among NLRP3 inflammasome, energy metabolism, intestinal microflora metabolites, and inflammation, as well as highlight advantages of NLRP3 inflammasome in treating HF.

Promoting brain health through physical activity among adults exposed to early life adversity: Potential mechanisms and theoretical framework

Adverse childhood experiences such as abuse, neglect, and poverty, profoundly alter neurobehavioral development in a manner that negatively impacts health across the lifespan. Adults who have been exposed to such adversities exhibit premature and more severe age-related declines in brain health. Unfortunately, it remains unclear whether the negative effects of early life adversity (ELA) on brain health can be remediated through intervention in adulthood. Physical activity may represent a low-cost behavioral approach to address the long-term consequences of ELA on brain health. However, there has been limited research examining the impact of physical activity on brain health among adults with a history of ELA. Accordingly, the purpose of this review is to (1) review the influence of ELA on brain health in adulthood and (2) highlight evidence for the role of neurotrophic factors, hypothalamic-adrenal-pituitary axis regulation, inflammatory processes, and epigenetic modifications in mediating the effects of both ELA and physical activity on brain health outcomes in adulthood. We then propose a theoretical framework to guide future research in this area.

The Role of the Inflammasome in Heart Failure

Inflammation promotes the development of heart failure (HF). The inflammasome is a multimeric protein complex that plays an essential role in the innate immune response by triggering the cleavage and activation of the proinflammatory cytokines interleukins (IL)-1β and IL-18. Blocking IL-1β with the monoclonal antibody canakinumab reduced hospitalizations and mortality in HF patients, suggesting that the inflammasome is involved in HF pathogenesis. The inflammasome is activated under various pathologic conditions that contribute to the progression of HF, including pressure overload, acute or chronic overactivation of the sympathetic system, myocardial infarction, and diabetic cardiomyopathy. Inflammasome activation is responsible for cardiac hypertrophy, fibrosis, and pyroptosis. Besides inflammatory cells, the inflammasome in other cardiac cells initiates local inflammation through intercellular communication. Some inflammasome inhibitors are currently being investigated in clinical trials in patients with HF. The current evidence suggests that the inflammasome is a critical mediator of cardiac inflammation during HF and a promising therapeutic target. The present review summarizes the recent advances in both basic and clinical research on the role of the inflammasome in HF.

Epigenetic signatures underlying inflammation: an interplay of nutrition, physical activity, metabolic diseases, and environmental factors for personalized nutrition

Aim and objective

Emerging translational evidence suggests that epigenetic alterations (DNA methylation, miRNA expression, and histone modifications) occur after external stimuli and may contribute to exacerbated inflammation and the risk of suffering several diseases including diabetes, cardiovascular diseases, cancer, and neurological disorders. This review summarizes the current knowledge about the harmful effects of high-fat/high-sugar diets, micronutrient deficiencies (folate, manganese, and carotenoids), obesity and associated complications, bacterial/viral infections, smoking, excessive alcohol consumption, sleep deprivation, chronic stress, air pollution, and chemical exposure on inflammation through epigenetic mechanisms. Additionally, the epigenetic phenomena underlying the anti-inflammatory potential of caloric restriction, n-3 PUFA, Mediterranean diet, vitamin D, zinc, polyphenols (i.e., resveratrol, gallic acid, epicatechin, luteolin, curcumin), and the role of systematic exercise are discussed.

Methods

Original and review articles encompassing epigenetics and inflammation were screened from major databases (including PubMed, Medline, Science Direct, Scopus, etc.) and analyzed for the writing of the review paper.

Conclusion

Although caution should be exercised, research on epigenetic mechanisms is contributing to understand pathological processes involving inflammatory responses, the prediction of disease risk based on the epigenotype, as well as the putative design of therapeutic interventions targeting the epigenome.

Low-grade chronic inflammation is attenuated by exercise training in obese adults through down-regulation of ASC gene in peripheral blood: a pilot study

Background

Obesity is characterized by low-grade chronic inflammation and an excess of adipose tissue. The ASC gene encodes a protein that is part of the NLRP3 inflammasome, a cytosolic multiprotein complex that is associated with inflammation and metabolic alterations. To our knowledge, there is no evidence regarding ASC gene activity in obese adults in response to lifestyle modifications.

Purpose

To evaluate the effect of hypocaloric diet and moderate-intensity structured exercise intervention on ASC gene expression and inflammatory markers in obese adults.

Methods

Thirty-seven obese individuals aged 25 to 50 years were randomized to the hypocaloric diet exercise group or hypocaloric diet group. The participants underwent a 4-month follow-up. Electrical bioimpedance was used for body composition analysis. Biochemical data were analyzed by dry chemistry and insulin levels by ELISA. ASC gene expression from peripheral blood was performed using real-time PCR. Dietary data was collected through questionnaires and analyzed using the Nutritionist Pro™ software. Quantification of cytokines was conducted using Bio-Plex Pro™ Human cytokine. The Astrand-Ryhming test was used to estimate the maximum oxygen volume and design the moderate-intensity structured exercise program ~ 75% heart rate (HR)

Results

After the intervention, both study groups significantly improved body composition (decreased weight, fat mass, waist circumference and abdominal obesity, p < 0.05). Besides, the diet-exercise group significantly decreased ASC mRNA expression, MCP-1, and MIP-1β inflammatory cytokines compared to the diet group (p < 0.05). While in the diet group, MCP-1 and IL-8 exhibited significantly decreased levels (p < 0.05). In the diet-exercise group, a positive correlation between the atherogenic index and waist circumference was found (r = 0.822, p = 0.011), and a negative correlation was observed between the delta of ASC mRNA expression and IL-10 levels at the end of the intervention (r = − 0.627, p = 0.019).

Conclusion

Low-grade chronic inflammation was attenuated through individualized exercise prescription and our findings highlight the role of the ASC gene in the inflammation of obese adults.

Trial registration

ClinicalTrials.gov, number NCT04315376. Registered 20 March 2020—retrospectively registered

Blockade of β-adrenergic signaling suppresses inflammasome and alleviates cardiac fibrosis

Background

Heart failure (HF) is an end-stage syndrome of all structural heart diseases which accompanies the loss of myocardium and cardiac fibrosis. Although the role of inflammasome in cardiac fibrosis has recently been a point of focus, the mechanism of inflammasome activation in HF has not yet been elucidated.

Methods

In this study, we investigated the expression of inflammasome proteins in a rat thoracic aorta constriction (TAC) model and cultured cardiac fibroblasts with stimulation of norepinephrine (NE).

Results

Our results showed that levels of inflammasome proteins in the myocardial of TAC rats were elevated. By blocking β-adrenergic signaling in the rats, inflammasome activation was suppressed and heart function was improved. The stimulation of cultured cardiac fibroblasts with NE activated inflammasome in vitro, which was abrogated by the inhibition of the calcium channels and reactive oxygen species (ROS). The activation of inflammasome by NE promoted cardiac fibrosis, whereas the inhibition of the calcium channels, ROS, and inflammasome reduced this effect.

Conclusions

The present study indicated that activation of inflammasome by β-adrenergic signaling promotes cardiac fibrosis. Therefore, modulation of inflammasome during HF might provide a novel strategy to treat this disease.

Altered inflammasome machinery as a key player in the perpetuation of Rett syndrome oxinflammation

Rett syndrome (RTT) is a progressive neurodevelopmental disorder mainly caused by mutations in the X-linked MECP2 gene. RTT patients show multisystem disturbances associated with an oxinflammatory status. Inflammasomes are multi-protein complexes, responsible for host immune responses against pathogen infections and redox-related cellular stress. Assembly of NLRP3/ASC inflammasome triggers pro-caspase-1 activation, thus, resulting in IL-1β and IL-18 maturation. However, an aberrant activation of inflammasome system has been implicated in several human diseases. Our aim was to investigate the possible role of inflammasome in the chronic subclinical inflammatory condition typical of RTT, by analyzing this complex in basal and lipopolysaccharide (LPS)+ATP-stimulated primary fibroblasts, as well as in serum from RTT patients and healthy volunteers. RTT cells showed increased levels of nuclear p65 and ASC proteins, pro-IL-1β mRNA, and NLRP3/ASC interaction in basal condition, without any further response upon the LPS + ATP stimuli. Moreover, augmented levels of circulating ASC and IL-18 proteins were found in serum of RTT patients, which are likely able to amplify the inflammatory response. Taken together, our findings suggest that RTT patients exhibited a challenged inflammasome machinery at cellular and systemic level, which may contribute to the subclinical inflammatory state feedback observed in this pathology.

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RTT cell shows a constitutive NFκB activation.

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Aberrant activation of inflammasome system is evident in RTT.

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This new evidence can explain the demonstrated subclinical inflammation in RTT.

Effects of Exercise on ASC Methylation and IL-1 Cytokines in Heart Failure

INTRODUCTION/PURPOSE

Inflammation contributes to heart failure (HF) progression and the interleukin (IL)-1 cytokine IL-1β is implicated in this process. The adaptor protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is necessary for inflammasome activation of IL-1β. Lower ASC methylation is associated with worse outcomes in HF. The purpose of this study was to examine the effects of exercise on changes in ASC methylation and activation of the IL-1 family cytokine IL-1β in persons with HF.

METHODS

Participants (N = 54) were randomized to receive exercise intervention (n = 38) or attention control (n = 16) for 3 months. Percent methylation of the ASC gene, plasma IL-1β, and ASC mRNA and were obtained at baseline, 3 months, and 6 months.

RESULTS

ASC methylation was higher in the exercise group as compared to control at 3 months (6.10% ± 0.5% vs 5.80% ± 0.4%; P = 0.04) and 6 months (6.07 ± 0.4 vs 5.82 ± 0.4; P = 0.04). Plasma IL-1β was lower in the exercise group at 3 months (1.43 ± 0.5 pg·mL vs 2.09 ± 1.3 pg·mL; P = 0.02) and 6 months (1.49 ± 0.5 pg·mL vs 2.13 ± 1.4 pg·mL; P = 0.004). ASC mRNA expression was negatively associated with ASC methylation at baseline (r = -0.97, P = 0.001), 3 months (r = -0.90, P = 0.001), and 6 months (r = -0.81, P = 0.001). ASC mRNA was lower than baseline at 3 months (P = 0.004) and 6 months (P = 0.002) among those in the exercise group. ASC methylation was positively associated with 6-min walk test at baseline (r = 0.517, P < 0.001), 3 months (r = 0.464, P = 0.004), and 6 months (r = 497, P = 0.05).

CONCLUSIONS

Exercise was related to increased mean percent ASC methylation and decreased IL-1β and ASC mRNA gene expression in HF. Epigenetic regulation of ASC can be a biological mechanism by which exercise can promote better outcomes in HF.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

Association Analysis of NLRP3 Inflammation-Related Gene Promotor Methylation as Well as Mediating Effects on T2DM and Vascular Complications in a Southern Han Chinese Population

Objective: To explore the association between the methylation levels in the promoter regions of the NLRP3, AIM2, and ASC genes and T2DM and its vascular complications in a Southern Han Chinese population and further analyze their interaction and mediating effects with environmental factors in T2DM. Methods: A case-control study was used to determine the association between population characteristics, the methylation level in the promoter region of the NLRP3, AIM2, and ASC genes and T2DM and vascular complications. A mediating effect among genes-environment-T2DM and the interaction of gene-gene or gene-environment factors was explored. Results: In the logistic regression model with adjusted covariants, healthy people with lower total methylation levels in the AIM2 promoter region exhibited a 2.29-fold [OR: 2.29 (1.28~6.66), P = 0.011] increased risk of developing T2DM compared with higher-methylation individuals. T2DM patients without any vascular complications who had lower methylation levels (<methylation median) in NLRP3 CpG2 and AIM2 total methylation had 6.45 (OR: 6.45, 95% CI: 1.05~39.78, P = 0.011) and 9.48 (OR: 9.48, 95% CI: 1.14~79.00, P = 0.038) times higher risks, respectively, of developing diabetic microvascular complications than T2DM patients with higher methylation. Similar associations were also found between the lower total methylation of the NLRP3 and AIM2 promoter regions and macrovascular complication risk (NLRP3 OR: 36.03, 95% CI: 3.11~417.06, P = 0.004; AIM2 OR: 30.90, 95% CI: 2.59~368.49, P = 0.007). Lower NLRP3 promoter total methylation was related to a 17.78-fold increased risk of micro-macrovascular complications (OR: 17.78, 95% CI: 2.04~155.28, P = 0.009). Lower ASC CpG1 or CpG3 methylation levels had significant partial mediating effects on T2DM vascular complications caused by higher age (ASC CpG1 explained approximately 52.8% or 32.9% of the mediating effect of age on macrovascular or macro-microvascular complications; ASC CpG3 explained approximately 38.9% of the mediating effect of age on macrovascular complications). No gene-gene or gene-environment interaction was identified in T2DM. Conclusion: Lower levels of AIM2 promoter total methylation might increase the risk of T2DM. NLRP3, AIM2, and ASC promoter total methylation or some CpG methylation loss might increase the risk of T2DM vascular complications, which merits further study to support the robustness of these findings.

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.