Prevention of cardiac hypertrophy and heart failure by silencing of NF-kappaB

Ellagic acid protects against angiotensin II-induced hypertrophic responses through ROS-mediated MAPK pathway in H9c2 cells

The early myocardial response of hypertension is an elevation of angiotensin-II (Ang-II) concentration, leading to heart failure and cardiac hypertrophy. This hypertrophic event of the heart is mediated by the interaction of Ang type 1 receptors (AT-R1), thereby modulating NADPH oxidase activity in cardiomyocytes, which alters redox status in cardiomyocytes. Ellagic acid (EA) has anti-inflammatory and anti-oxidative capacities. Thus, EA has potential preventive effects on cardiovascular diseases and diabetes. In the last decades, because the protective effect of EA on Ang-II-induced hypertrophic responses is unclear, this study aims to investigate the protective effect of EA in cardiomyocytes. H9c2 cells were treated to Ang-II 1 μM for 24 h to induce cellular damage. We found that EA protected against Ang-II-increased cell surface area and pro-hypertrophic gene expression in H9c2. EA reduced Ang-II-caused AT-R1 upregulation, thereby inhibiting oxidative stress NADPH oxidase activation. EA mitigated Ang-II-enhanced p38 and extracellular-signal-regulated kinase (ERK) phosphorylation. Moreover, EA treatment under Ang-II stimulation also reversed NF-κB activity and iNOS expression. This study shows that EA protects against Ang-II-induced myocardial hypertrophy and attenuates oxidative stress through reactive oxygen species-mediated mitogen-activated protein kinase signaling pathways in H9c2 cells. Thus, EA may be an effective compound for preventing Ang-II-induced myocardial hypertrophy.

Mitochondrial Ca2+ Uniporter-Dependent Energetic Dysfunction Drives Hypertrophy in Heart Failure

The role of the mitochondrial calcium uniporter (MCU) in energy dysfunction and hypertrophy in heart failure (HF) remains unknown. In angiotensin II (ANGII)-induced hypertrophic cardiac cells we have shown that hypertrophic cells overexpress MCU and present bioenergetic dysfunction. However, by silencing MCU, cell hypertrophy and mitochondrial dysfunction are prevented by blocking mitochondrial calcium overload, increase mitochondrial reactive oxygen species, and activation of nuclear factor kappa B-dependent hypertrophic and proinflammatory signaling. Moreover, we identified a calcium/calmodulin-independent protein kinase II/cyclic adenosine monophosphate response element-binding protein signaling modulating MCU upregulation by ANGII. Additionally, we found upregulation of MCU in ANGII-induced left ventricular HF in mice, and in the LV of HF patients, which was correlated with pathological remodeling. Following left ventricular assist device implantation, MCU expression decreased, suggesting tissue plasticity to modulate MCU expression.

Meta-analysis reveals differential gene expression in tetralogy of Fallot versus controls

OBJECTIVES

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect in the United States. We aimed to identify genetic variations associated with TOF using meta-analysis of publicly available digital samples to spotlight targets for prevention, screening, and treatment strategies.

METHODS

We used the Search Tag Analyze Resource for Gene Expression Omnibus (STARGEO) platform to identify 39 TOF and 19 non-TOF right ventricle tissue samples from microarray data and identified upregulated and downregulated genes. Associated gene expression data were analyzed using ingenuity pathway analysis and restricted to genes with a statistically significant (p < .05) difference and an absolute experimental log ratio >0.1 between disease and control samples.

RESULTS

Our analysis identified 220 genes whose expression profiles were significantly altered in TOF vs. non-TOF samples. The most striking differences identified in gene expression included genes FBXO32, PTGES, MYL12a, and NR2F2. Some top associated canonical pathways included adrenergic signaling, estrogen receptor signaling, and the role of NFAT in cardiac hypertrophy. In general, genes involved in adaptive, defensive, and reparative cardiovascular responses showed altered expression in TOF vs. non-TOF samples.

CONCLUSIONS

We introduced the interpretation of open "big data" using the STARGEO platform to define robust genomic signatures of congenital heart disease pathology of TOF. Overall, our meta-analysis results indicated increased metabolism, inflammation, and altered gene expression in TOF patients. Estrogen receptor signaling and the role of NFAT in cardiac hypertrophy represent unique pathways upregulated in TOF patients and are potential targets for future pharmacologic treatments.

JMJD6 protects against isoproterenol-induced cardiac hypertrophy via inhibition of NF-κB activation by demethylating R149 of the p65 subunit

Histone modification plays an important role in pathological cardiac hypertrophy and heart failure. In this study we investigated the role of a histone arginine demethylase, Jumonji C domain-containing protein 6 (JMJD6) in pathological cardiac hypertrophy. Cardiac hypertrophy was induced in rats by subcutaneous injection of isoproterenol (ISO, 1.2 mg·kg-1·d-1) for a week. At the end of the experiment, the rats underwent echocardiography, followed by euthanasia and heart collection. We found that JMJD6 levels were compensatorily increased in ISO-induced hypertrophic cardiac tissues, but reduced in patients with heart failure with reduced ejection fraction (HFrEF). Furthermore, we demonstrated that JMJD6 overexpression significantly attenuated ISO-induced hypertrophy in neonatal rat cardiomyocytes (NRCMs) evidenced by the decreased cardiomyocyte surface area and hypertrophic genes expression. Cardiac-specific JMJD6 overexpression in rats protected the hearts against ISO-induced cardiac hypertrophy and fibrosis, and rescued cardiac function. Conversely, depletion of JMJD6 by single-guide RNA (sgRNA) exacerbated ISO-induced hypertrophic responses in NRCMs. We revealed that JMJD6 interacted with NF-κB p65 in cytoplasm and reduced nuclear levels of p65 under hypertrophic stimulation in vivo and in vitro. Mechanistically, JMJD6 bound to p65 and demethylated p65 at the R149 residue to inhibit the nuclear translocation of p65, thus inactivating NF-κB signaling and protecting against pathological cardiac hypertrophy. In addition, we found that JMJD6 demethylated histone H3R8, which might be a new histone substrate of JMJD6. These results suggest that JMJD6 may be a potential target for therapeutic interventions in cardiac hypertrophy and heart failure.

Resveratrol prevents Ang II-induced cardiac hypertrophy by inhibition of NF-κB signaling

BACKGROUND

Pathological cardiac hypertrophy is a hallmark of various cardiovascular diseases (CVD) including chronic heart failure (HF) and an important target for the treatment of these diseases. Aberrant activation of Angiotensin II (Ang II)/AT1R signaling pathway is one of the main triggers of cardiac hypertrophy, which further gives rise to excessive inflammation that is mediated by the key transcription factor NF-κB. Resveratrol (REV) is a natural polyphenol with multiple anti-inflammatory and anti-oxidative effects, however the ability of REV in preventing Ang II-induced cardiac hypertrophy in combination with NF-κB signaling activation remains unclear.

METHODS

Murine models of cardiac hypertrophy was conducted via implantation of Ang II osmotic pumps. Primary neonatal rat cardiomyocyte and heart tissues were examined to determine the effect and underlying mechanism of REV in preventing Ang II-induced cardiac hypertrophy.

RESULTS

Administrations of REV significantly prevented Ang II-induced cardiac hypertrophy, as well as robustly attenuated Ang II-induced cardiac fibrosis, and cardiac dysfunction. Furthermore, REV not only directly prevented Ang II/AT1R signal transductions, but also prevented Ang II-induced expressions of pro-inflammatory cytokines and activation of NF-κB signaling pathway.

CONCLUSIONS

Our study provides important new mechanistic insight into the cardioprotective effects of REV in preventing Ang II-induced cardiac hypertrophy via inhibiting adverse NF-κB signaling activation. Our findings further suggest the therapeutic potential of REV as a promising drug for the treatment of cardiac hypertrophy and heart failure.

Impact of atmospheric variables on incidence of acute coronary syndrome amongst Gujarati Asian Indians - IOAPIC study

OBJECTIVES

The study evaluated the effects of climatic conditions and its variables on incidence of ACS in Gujarati Asian Indians.

METHODS

In this multicentric, retrospective, observational case control study of a total of 3256 patients, the Electronic Medical Records (EMS) of all 740 patients who were hospitalised for ACS at the 2 tertiary care centres of Ahmedabad over 3 years between January 2017 to December 2019 were compared with demographically matched 2516 non- ACS, CAD controls were compared for the impact of climatic parameters viz. temperature, barometric pressure, humidity as reported by monthly averages by the state meteorological department for monthly incidence of ACS.

RESULTS

The highest number of ACS cases were observed during the month of September (N=127; 27%) followed by August (N=123; 26%). Higher humidity and decreasing atmospheric pressure were associated with highest occurrence of ACS in the state of Gujarat. ST elevation Myocardial Infarction (STEMI) was the most common type of ACS (N=598; 80.8%). In ACS, the Coefficient of correlation for humidity was 0.712 (P= 0.009), while that for temperature was 0.506 (P=0.093). Effect of atmospheric pressure was found to be significant with a negative Coefficient of correlation of -0.571 (P=0.052). However amongst the controls, the coefficient of correlation for humidity was 0.062 (P=0.722) and atmospheric pressure Correlation coefficient was 0.107 (P=0.539) non-significant.

CONCLUSIONS

The higher humidity/temperature and lower atmospheric pressure had a positive correlation with the incidence of ACS with highest incidence noted in August and September in the state of Gujarat.

Inappropriate Activation of TLR4/NF-κB is a Cause of Heart Failure

Significance: Heart failure, a disease with extremely high incidence, is closely associated with inflammation and oxidative stress. The Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway plays an important role in the occurrence and development of heart failure.

Recent advances: Previous studies have shown that TLR4/NF-κB causes heart failure by inducing oxidative stress and inflammation; damaging the endothelia; promoting fibrosis; and inducing myocardial hypertrophy, apoptosis, pyroptosis, and autophagy.

Critical issues: Understanding the pathogenesis of heart failure is essential for the treatment of this disease. In this review, we outline the mechanisms underlying TLR4/NF-κB pathway-mediated heart failure and discuss drugs that alleviate heart failure by regulating the TLR4/NF-κB pathway.

Future directions: During TLR4/NF-κB overactivation, interventions targeting specific receptor antagonists may effectively alleviate heart failure, thus providing a basis for the development of new anti-heart failure drugs.

Upregulation of Phospholipase C Gene Expression Due to Norepinephrine-Induced Hypertrophic Response

The activation of phospholipase C (PLC) is thought to have a key role in the cardiomyocyte response to several different hypertrophic agents such as norepinephrine, angiotensin II and endothelin-1. PLC activity results in the generation of diacylglycerol and inositol trisphosphate, which are downstream signal transducers for the expression of fetal genes, increased protein synthesis, and subsequent cardiomyocyte growth. In this article, we describe the signal transduction elements that regulate PLC gene expression. The discussion is focused on the norepinephrine- α₁-adrenoceptor signaling pathway and downstream signaling processes that mediate an upregulation of PLC isozyme gene expression. Evidence is also indicated to demonstrate that PLC activities self-regulate the expression of PLC isozymes with the suggestion that PLC activities may be part of a coordinated signaling process for the perpetuation of cardiac hypertrophy. Accordingly, from the information provided, it is plausible that specific PLC isozymes could be targeted for the mitigation of cardiac hypertrophy.

Investigation of the Potential Key Genes and the Multitarget Mechanisms of Polygonum cuspidatum against Heart Failure Based on Network Pharmacology and Experimental Validation

In this study, systematic pharmacology and bioinformatic approaches were employed to identify the potential targets of Polygonum cuspidatum (PC) for treating heart failure (HF). The active ingredients of PC were screened by using the TCMSP database, and HF-related genes were identified in the GEO database. Then, the herb-HF targeted-gene networks were constructed using Cytoscape software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional analyses were performed to obtain the enriched molecular pathways associated with the pathogenesis of HF. Finally, in vitro experiment was performed to evidence network pharmacology analysis. 170 intersection genes were obtained, and key genes (FOXO3, NFKB1, and TNF) were identified. Besides, GO and KEGG findings indicated that PC treatment of HF was achieved via regulating apoptosis, IL-17 signaling pathway, TNF signaling pathway, response to oxidative stress, and response to reactive oxygen species. And cell experiment revealed that PC could decrease the expression of NFKB1 and TNF and increase the expression of FOXO3, SOD1, and GPX1 in H9C2 cells. These findings showed that the therapeutic mechanism of PC in the treatment of HF may be associated with the regulation of inflammation-related and oxidative stress-related genes.

Can Epigenetics Help Solve the Puzzle Between Concomitant Cardiovascular Injury and Severity of Coronavirus Disease 2019?

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has significant implications in patients with concomitant cardiovascular disease (CVD) because they are the population at the greatest risk of death. The treatment of such patients and complications may represent a new challenge for the fields of cardiology and pharmacology. Thus, understanding the involvement of this viral infection in CVD might help to reduce the aggressiveness of SARS-CoV-2 in causing multiorgan infection and damage. SARS-CoV-2 disturbs the host epigenome and several epigenetic processes involved in the pathophysiology of COVID-19 that can directly affect the function and structure of the cardiovascular system (CVS). Hence, it would be relevant to identify epigenetic alterations that directly impact CVS physiology after SARS-CoV-2 infection. This could contribute to the view of this virus-induced CVS injury and direct forthcoming tackles for COVID-19 treatment to reduce mortality in patients with CVD. Targeting epigenetic marks could offer strong evidence for the development of novel antiviral therapies, especially in the context of COVID-19-related CVS damage. In this review, we address some of the main signaling pathways that are currently known as being involved in COVID-19 pathophysiology and the importance of this glint on epigenetics and some of its modifiers (epidrugs) to control the unregulated epitope activity in the context of SARS-CoV-2 infection, COVID-19, and underlying CVD.

Measuring hypertrophy in neonatal rat primary cardiomyocytes and human iPSC-derived cardiomyocytes

In the heart, left ventricular hypertrophy is initially an adaptive mechanism that increases wall thickness to preserve normal cardiac output and function in the face of coronary artery disease or hypertension. Cardiac hypertrophy develops in response to pressure and volume overload but can also be seen in inherited cardiomyopathies. As the wall thickens, it becomes stiffer impairing the distribution of oxygenated blood to the rest of the body. With complex cellular signalling and transcriptional networks involved in the establishment of the hypertrophic state, several model systems have been developed to better understand the molecular drivers of disease. Immortalized cardiomyocyte cell lines, primary rodent and larger animal models have all helped understand the pathological mechanisms underlying cardiac hypertrophy. Induced pluripotent stem cell-derived cardiomyocytes are also used and have the additional benefit of providing access to human samples with direct disease relevance as when generated from patients suffering from hypertrophic cardiomyopathies. Here, we briefly review in vitro and in vivo model systems that have been used to model hypertrophy and provide detailed methods to isolate primary neonatal rat cardiomyocytes as well as to generate cardiomyocytes from human iPSCs. We also describe how to model hypertrophy in a "dish" using gene expression analysis and immunofluorescence combined with automated high-content imaging.

The Effect of Daily Methylsulfonylmethane (MSM) Consumption on High-Density Lipoprotein Cholesterol in Healthy Overweight and Obese Adults: A Randomized Controlled Trial

Interventions to decrease inflammation and improve metabolic function hold promise for the prevention of obesity-related diseases. Methylsulfonylmethane (MSM) is a naturally occurring compound that demonstrates antioxidant and anti-inflammatory effects. Improvements in measures of metabolic health have been observed in mouse models of obesity and diabetes following MSM treatment. However, the effects of MSM on obesity-related diseases in humans have not been investigated. Therefore, the purpose of this investigation was to determine whether MSM supplementation improves cardiometabolic health, and markers of inflammation and oxidative status. A randomized, double-blind, placebo-controlled design was utilized with a total of 22 overweight or obese adults completing the study. Participants received either a placebo (white rice flour) or 3 g MSM daily for 16 weeks. Measurements occurred at baseline and after 4, 8, and 16 weeks. Outcome measures included fasting glucose, insulin, blood lipids, blood pressure, body composition, metabolic rate, and markers of inflammation and oxidative status. The primary finding of this work shows that high-density lipoprotein cholesterol was elevated at 8 and 16 weeks of daily MSM consumption compared to baseline, (p = 0.008, p = 0.013). Our findings indicate that MSM supplementation may improve the cholesterol profile by resulting in higher levels of high-density lipoprotein cholesterol.

A novel inflammatory signaling pathway in patients with slow coronary flow: NF-κB/IL-1β/nitric oxide

PURPOSE

The slow coronary flow (SCF) was identified as delayed opacification of epicardial coronary arteries in the absence of stenotic lesion. Metabolic syndrome (MetS), oxidative stress, and inflammation may be possible known insulting factors for the pathogenesis of SCF. This investigation aimed to assess the relationship between some inflammatory markers, oxidative stress parameters and MetS components with SCF phenomenon.

METHODS

A total of 35 patients with SCF and 35 subjects with normal coronary flow (NCF) were included in the study. We assessed some inflammatory markers (IL-1β, IL-18, TNF-α, and NF-κB mRNA expression in peripheral blood mononuclear cells (PBMCs)). Moreover, blood samples of the participants were tested for total antioxidant capacity (TAC), glutathione peroxidase (GPX) and nitric oxide (NO) levels using enzyme-linked immunosorbent assay (ELISA). Diagnosis of MetS was based on the National Cholesterol Education Program's Adult Treatment Panel III report (ATPIII) criteria, 2005. Diagnostic criteria for coronary flow rates of all subjects were documented by thrombolysis in myocardial infarction (TIMI) frame count method.

RESULTS

SCF patients had significantly higher prevalence of MetS (46%, p = 0.048).We found that the level of TAC was significantly higher in the NCF group (p = 0.006). Furthermore, the NO concentration was significantly lower in SCF groups (p = 0.001). A significant incremental difference was detected in IL-1β (fold change 2.82 ± 0.31, p < 0.05) and NF-κB (fold change 4.62 ± 0.32, p < 0.05) mRNA expression in the SCF group when compared with its level in the NCF group. Furthermore, according to logistic regression analysis, there were significant associations between IL-1β, NF-κB expression levels and the incidence of SCF (p < 0.05).

CONCLUSION

Based on the findings of this study, the pathogenesis of the SCF phenomenon may be closely associated with metabolic syndrome and inflammation. The NF-κB/IL-1β/nitric oxide & MetS signaling pathway might be considered as potential therapeutic targets in the management of SCF patients but further researches is required to guarantee these findings.

Various aspects of inflammation in heart failure

Despite significant advances in the prevention and treatment of heart failure (HF), the prognosis in patients who have been hospitalised on at least one occasion due to exacerbation of HF is still poor. Therefore, a better understanding of the underlying pathophysiological mechanisms of HF is crucial in order to achieve better results in the treatment of this clinical syndrome. One of the areas that, for years, has aroused the interest of researchers is the activation of the immune system and the elevated levels of biomarkers of inflammation in patients with both ischaemic and non-ischaemic HF. Additionally, it is intriguing that the level of circulating pro-inflammatory biomarkers correlates with the severity of the disease and prognosis in this group of patients. Unfortunately, clinical trials aimed at assessing interventions to modulate the inflammatory response in HF have been disappointing, and the modulation of the inflammatory response has had either no effect or even a negative effect on the HF prognosis. The article presents a summary of current knowledge on the role of immune system activation and inflammation in the pathogenesis of HF. Understanding the immunological mechanisms pathogenetically associated with left ventricular remodelling and progression of HF may open up new therapeutic possibilities for HF.

UCHL1 inhibition attenuates cardiac fibrosis via modulation of nuclear factor-κB signaling in fibroblasts

The ubiquitin-proteasome system (UPS) plays an essential role in cellular homeostasis and myocardial function. Ubiquitin carboxy-terminal hydrolase 1 (UCHL1) is involved in cardiac remodeling, but its underlying mechanisms are largely unknown. Here, we observed that the UCHL1 was significantly up-regulated in angiotensin II-infused heart and primary cardiac fibroblast (CF). Systemic administration of the UCHL1 inhibitor LDN57444 significantly ameliorated cardiac fibrosis and improved cardiac function induced by angiotensin II. Also, LDN57444 inhibited CF cell proliferation as well as attenuated collagen I, and CTGF gene expression in the presence of Ang II. Mechanistically, UCHL1 promotes angiotensin II-induced fibrotic responses by way of activating nuclear factor kappa B (NF-κB) signaling. Moreover, suppression of the NF-κB pathway interfered with UCHL1 overexpression-mediated fibrotic responses. Besides, the chromatin immunoprecipitation assay demonstrated that NF-κB can bind to the UCHL1 promoter and trigger its transcription in cardiac fibroblasts. These findings suggest that UCHL1 positively regulates cardiac fibrosis by modulating NF-κB signaling pathway and identify UCHL1 could be a new treatment strategy for cardiac fibrosis.

Transcriptomic Analysis of Right Ventricular Remodeling in Two Rat Models of Pulmonary Hypertension: Identification and Validation of Epithelial-to-Mesenchymal Transition in Human Right Ventricular Failure

BACKGROUND

Right ventricular (RV) dysfunction is a significant prognostic determinant of morbidity and mortality in pulmonary arterial hypertension (PAH). Despite the importance of RV function in PAH, the underlying molecular mechanisms of RV dysfunction secondary to PAH remain unclear. We aim to identify and compare molecular determinants of RV failure using RNA sequencing of RV tissue from 2 clinically relevant animal models of PAH.

METHODS

We performed RNA sequencing on RV from rats treated with monocrotaline or Sugen with hypoxia/normoxia. PAH and RV failure were confirmed by catheterization and echocardiography. We validated the RV transcriptome results using quantitative real-time polymerase chain reaction, immunofluorescence, and Western blot. Immunohistochemistry and immunofluorescence were performed on human RV tissue from control (n=3) and PAH-induced RV failure patients (n=5).

RESULTS

We identified similar transcriptomic profiles of RV from monocrotaline- and Sugen with hypoxia-induced RV failure. Pathway analysis showed genes enriched in epithelial-to-mesenchymal transition, inflammation, and metabolism. Histological staining of human RV tissue from patients with RV failure secondary to PAH revealed significant RV fibrosis and endothelial-to-mesenchymal transition, as well as elevated cellular communication network factor 2 (top gene implicated in epithelial-to-mesenchymal transition/endothelial-to-mesenchymal transition) expression in perivascular areas compared with normal RV.

CONCLUSIONS

Transcriptomic signature of RV failure in monocrotaline and Sugen with hypoxia models showed similar gene expressions and biological pathways. We provide translational relevance of this transcriptomic signature using RV from patients with PAH to demonstrate evidence of epithelial-to-mesenchymal transition/endothelial-to-mesenchymal transition and protein expression of cellular communication network factor 2 (CTGF [connective tissue growth factor]). Targeting specific molecular mechanisms responsible for RV failure in monocrotaline and Sugen with hypoxia models may identify novel therapeutic strategies for PAH-associated RV failure.

HDL cholesterol: A potential mediator of the association between urinary cadmium concentration and cardiovascular disease risk

Evidence from previous studies has shown that exposure to metals is associated with cardiovascular disease (CVD). However, the association between metal mixtures and CVD risk and the potential mechanisms in epidemiologic studies remain unclear. The data of 14,795 adults who participated in the U.S. National Health and Nutrition Examination Survey (NHANES) 1999-2016 were analyzed. Multivariate logistic regression was performed to investigate the associations between urinary metal levels and CVDs. Weighted quantile sum (WQS) regression was performed to examine the effects of mixed metals on CVDs. Multivariate linear regression and mediation analysis were conducted to explore the associations between metals and blood lipids. Urinary cadmium (Cd) was significantly associated with an increased total CVD risk and with individual CVD risk. The odds ratio (OR) for CVD in the highest quartile of the WQS index was 1.43 (95% confidence interval [CI]: 1.19, 1.71). One augmented urinary Cd concentration unit (Log10) was associated with a 0.93 mg/dL decrease in HDL cholesterol, a 1.34 mg/dL increase in LDL cholesterol and a 1.30 mg/dL increase in total cholesterol in the fully adjusted model. Mediation analysis showed that HDL cholesterol mediated 4.91% of the association between urinary Cd and the prevalence of CVD. Our findings suggest that urinary Cd and metal mixtures were significantly and positively associated with CVD. The downregulation of HDL cholesterol might play a significant role in mediating Cd exposure-associated CVD risk increases.

Resolution-Based Therapies: The Potential of Lipoxins to Treat Human Diseases

Inflammation is an a physiological response instead an essential response of the organism to injury and its adequate resolution is essential to restore homeostasis. However, defective resolution can be the precursor of severe forms of chronic inflammation and fibrosis. Nowadays, it is known that an excessive inflammatory response underlies the most prevalent human pathologies worldwide. Therefore, great biomedical research efforts have been driven toward discovering new strategies to promote the resolution of inflammation with fewer side-effects and more specificity than the available anti-inflammatory treatments. In this line, the use of endogenous specialized pro-resolving mediators (SPMs) has gained a prominent interest. Among the different SPMs described, lipoxins stand out as one of the most studied and their deficiency has been widely associated with a wide range of pathologies. In this review, we examined the current knowledge on the therapeutic potential of lipoxins to treat diseases characterized by a severe inflammatory background affecting main physiological systems, paying special attention to the signaling pathways involved. Altogether, we provide an updated overview of the evidence suggesting that increasing endogenously generated lipoxins may emerge as a new therapeutic approach to prevent and treat many of the most prevalent diseases underpinned by an increased inflammatory response.

Effect of Cryptotanshinone on Measures of Rat Cardiomyocyte Oxidative Stress and Gene Activation Associated with Apoptosis

BACKGROUND

Oxidative stress is a key factor that results in cardiomyocyte apoptosis and cardiovascular diseases. Cryptotanshinone (CTS), one of the major bioactive constitutes extracted from the root of the plant Salvia miltiorrhizaBunge, has been widely studied for various disease treatments. However, the roles of CTS on cardiomyocytes remain unclear.

METHODS

In the present study, neonatal rat cardiomyocytes were pretreated with CTS for 4 h before being exposed to H2O2. Cell viability for the cells with or without pretreatment with CTS before exposure to H2O2 was evaluated by the MTT assay. Production of lactate dehydrogenase (LDH), nitric oxide (NO), prostaglandin E2 (PGE2), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxides (GSH-Px) was quantified by corresponding detection kits. The mRNA levels of Bcl-2 antiapoptotic and Bax-like proapoptotic genes were quantified with RT-PCR. Production of reactive oxygen species (ROS) was qualified and quantified with a dichlorofluorescein diacetate cellular ROS detection assay kit. The extracellular signal-related kinase (ERK) phosphorylation and nuclear factor κB (NF-κB) activation were measured by Western blot.

RESULTS

Our results revealed that the CTS pretreatment could enhance cell viability and promote Bcl-2 antiapoptotic gene expression. Additionally, CTS could abolish the H2O2-induced production of NO, LDH, and PGE2. Consistent with these findings, CTS could inhibit ROS and MDA production and promote SOD, CAT, and GSH-Px activities. Mechanistically, CTS may achieve these processes by inhibiting ERK and NF-κB signal pathways.

CONCLUSION

CTS protects cardiomyocytes against the H2O2-induced cellular injuries through ERK and NF-κB inactivation and ROS scavenging. Therefore, CTS is a promising reagent against ROS-induced cardiomyopathy.

Key Player in Cardiac Hypertrophy, Emphasizing the Role of Toll-Like Receptor 4

Toll-like receptor 4 (TLR4), a key pattern recognition receptor, initiates the innate immune response and leads to chronic and acute inflammation. In the past decades, accumulating evidence has implicated TLR4-mediated inflammatory response in regulation of myocardium hypertrophic remodeling, indicating that regulation of the TLR4 signaling pathway may be an effective strategy for managing cardiac hypertrophy's pathophysiology. Given TLR4's significance, it is imperative to review the molecular mechanisms and roles underlying TLR4 signaling in cardiac hypertrophy. Here, we comprehensively review the current knowledge of TLR4-mediated inflammatory response and its interaction ligands and co-receptors, as well as activation of various intracellular signaling. We also describe the associated roles in promoting immune cell infiltration and inflammatory mediator secretion, that ultimately cause cardiac hypertrophy. Finally, we provide examples of some of the most promising drugs and new technologies that have the potential to attenuate TLR4-mediated inflammatory response and prevent or reverse the ominous cardiac hypertrophy outcomes.

The Mechanism Underlying the Protective Effects of Tannic Acid Against Isoproterenol-Induced Myocardial Fibrosis in Mice

Tannic acid (TA) belongs to a class of complex water-soluble polyphenolic derivatives that show anticarcinogenic, antiinflammatory, antioxidant, and scavenging activities. Here, we investigate the protective effects of TA against isoproterenol (ISO)-induced myocardial fibrosis (MF) in mice. Mice received TA and ISO dosing and were sacrificed 48 h later. The activities of creatine kinase (CK), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and mitochondria enzymes were measured. Cardiac histopathology was done using H&E, Sirius red, and Masson’s Trichrome staining. Immunohistochemical staining was applied to indicate changes in B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), and basic fibroblast growth factor (bFGF) protein expressions in cardiac tissue. RT-PCR was used to measure the expression of atrial and brain natriuretic peptides (ANP and BNP, respectively), c-fos, and c-jun. Western blotting was used to measure the expression of nuclear factor-κB (NF-κB) p65, phosphorylated NF-κB p65), toll-like receptor 4 (TLR4), p38, phosphorylated p38, Bax, Bcl-2, and caspase-3. Compared to the ISO group, the TA group had reduced levels of TLR4, p38, p-p38, NF-κB (p65), p-NF-κB (p-p65), caspase-3, Bax, and Bcl-2, as well as CK, CK-MB, and LDH. These results indicate that TA protects against ISO-induced MF, possibly through its ability to suppress the TLR4-mediated NF-κB signaling pathway.

Leukocyte immunoglobulin-like receptor B4 protects against cardiac hypertrophy via SHP-2-dependent inhibition of the NF-κB pathway

Cardiac hypertrophy is a complex pathological process, and the molecular mechanisms underlying hypertrophic remodeling have not been clearly elucidated. Leukocyte immunoglobulin-like receptor B4 (lilrb4) is an inhibitory transmembrane protein that is necessary for the regulation of various cellular signaling pathways. To investigate whether lilrb4 plays a role in cardiac hypertrophy, we performed aortic banding in lilrb4 knockout mice, lilrb4 cardiac-specific transgenic mice, and their wild-type littermates. Cardiac hypertrophy was evaluated by echocardiographic, hemodynamic, pathological, and molecular analyses. We found that lilrb4 was expressed both in myocardial tissue and on cultured cardiomyocytes under basal conditions, but the expression was obviously decreased in mouse hearts following aortic banding and in cardiomyocytes treated with angiotensin II. Lilrb4 disruption aggravated cardiac hypertrophy, fibrosis, and dysfunction in response to pressure overload. Conversely, the cardiac overexpression of lilrb4 led to the opposite effects. Moreover, lilrb4 overexpression inhibited angiotensin II-induced cardiomyocyte hypertrophy in vitro. Mechanistically, we determined that the cardioprotective effect of lilrb4 was mediated through an interaction with SHP-2, the preservation of phosphorylated SHP-2, and the inhibition of the NF-κB pathway. In addition, SHP-2 knockdown in cardiomyocytes eliminated the inhibitory effects of lilrb4 on angiotensin II-induced hypertrophy and NF-κB activation. Our results suggest that lilrb4 protects against pathological cardiac hypertrophy via the SHP-2-dependent inhibition of the NF-κB pathway and may act as a potential therapeutic target for cardiac hypertrophy. KEY MESSAGES: Lilrb4 expression is decreased by hypertrophic stimuli. Lilrb4 protects against pathological cardiac hypertrophy. Lilrb4 interacts with SHP-2 and inhibits NF-κB pathway.

Relationship between urinary bisphenol a levels and cardiovascular diseases in the U.S. adult population, 2003-2014

BACKGROUND

Emerging evidence has identified cardiovascular system as a potential target of Bisphenol A (BPA). Although a few studies have revealed the relationship between BPA and the risk of several cardiovascular diseases (CVD) outcomes and CVD risk factors, no published studies have investigated the link between urinary BPA and the risk of stroke.

METHODS

Data were derived from the United States National Health and Nutrition Examination Surveys (NHANES), with a representative sample aged ≥20 years (n = 9139) from 2003 to 2014. We performed multivariable logistic regression model to estimate associations between quartiles and natural logarithm transformed urinary BPA concentrations and five specific CVD outcomes and total CVD.

RESULTS

In quartile analysis, highest level of urinary BPA was associated with increased prevalence of myocardial infarction (MI) (OR = 1.73, 95% CI = 1.11-2.69) and stroke (OR = 1.61, 95% CI = 1.09-2.36), when compared with those at the lowest quartile. Per unit (μg/g creatinine) increment in ln-transformed BPA concentration was shown to be significantly associated with 19%, 19%, 25%, 29%, 20%, and 16% increased odds ratios of prevalence of congestive heart failure, coronary heart disease (CHD), angina pectoris, MI, stroke and total CVD among total participants, respectively. Similar associations were found in males rather than in females.

CONCLUSION

We provided the premier evidence of positive relationship between urinary BPA concentration and stroke in U.S.

POPULATION

Urinary BPA levels were also positively correlated with congestive heart failure, CHD, angina pectoris, MI, as well as total CVD. These associations were more evident in males. Well-coordinated and prospective studies are warranted to gain the human effects of BPA on CVD.

SIRT3-mediated inhibition of FOS through histone H3 deacetylation prevents cardiac fibrosis and inflammation

Sirtuin 3 (SIRT3) is a deacetylase that modulates proteins that control metabolism and protects against oxidative stress. Modulation of SIRT3 activity has been proposed as a promising therapeutic target for ameliorating metabolic diseases and associated cardiac disturbances. In this study, we investigated the role of SIRT3 in inflammation and fibrosis in the heart using male mice with constitutive and systemic deletion of SIRT3 and human cardiac AC16 cells. SIRT3 knockout mice showed cardiac fibrosis and inflammation that was characterized by augmented transcriptional activity of AP-1. Consistent with this, SIRT3 overexpression in human and neonatal rat cardiomyocytes partially prevented the inflammatory and profibrotic response induced by TNF-α. Notably, these effects were associated with a decrease in the mRNA and protein levels of FOS and the DNA-binding activity of AP-1. Finally, we demonstrated that SIRT3 inhibits FOS transcription through specific histone H3 lysine K27 deacetylation at its promoter. These findings highlight an important function of SIRT3 in mediating the often intricate profibrotic and proinflammatory responses of cardiac cells through the modulation of the FOS/AP-1 pathway. Since fibrosis and inflammation are crucial in the progression of cardiac hypertrophy, heart failure, and diabetic cardiomyopathy, our results point to SIRT3 as a potential target for treating these diseases.

Therapeutic Potential of Lipoxin A4 in Chronic Inflammation: Focus on Cardiometabolic Disease

Several studies have shown that failure to resolve inflammation may contribute to the progression of many chronic inflammatory disorders. It has been suggested targeting the resolution of inflammation might be a novel therapeutic approach for chronic inflammatory diseases, including inflammatory bowel disease, diabetic complications, and cardiometabolic disease. Lipoxins [LXs] are a class of endogenously generated mediators that promote the resolution of inflammation. Biological actions of LXs include inhibition of neutrophil infiltration, promotion of macrophage polarization, increase of macrophage efferocytosis, and restoration of tissue homeostasis. Recently, several studies have demonstrated that LXs and synthetic analogues protect tissues from acute and chronic inflammation. The mechanism includes down-regulation of pro-inflammatory cytokines and chemokines (e.g., interleukin-1β and tumor necrosis factor-α), inhibition of the activation of the master pro-inflammatory pathway (e.g., nuclear factor κ-light-chain-enhancer of activated B cells pathway) and increased release of the pro-resolving cytokines (e.g., interleukin-10). Three generations of LXs analogues are well described in the literature, and more recently a fourth generation has been generated that appears to show enhanced potency. In this review, we will briefly discuss the potential therapeutic opportunity provided by lipoxin A₄ as a novel approach to treat chronic inflammatory disorders, focusing on cardiometabolic disease and the current drug development in this area.

An Integrated System Biology Approach Yields Drug Repositioning Candidates for the Treatment of Heart Failure

Identifying effective pharmacological treatments for heart failure (HF) patients remains critically important. Given that the development of drugs de novo is expensive and time consuming, drug repositioning has become an increasingly important branch. In the present study, we propose a two-step drug repositioning pipeline and investigate the novel therapeutic effects of existing drugs approved by the US Food and Drug Administration to discover potential therapeutic drugs for HF. In the first step, we compared the gene expression pattern of HF patients with drug-induced gene expression profiles to obtain preliminary candidates. In the second step, we performed a systems biology approach based on the known protein–protein interaction information and targets of drugs to narrow down preliminary candidates to obtain final candidates. Drug set enrichment analysis and literature search were applied to assess the performance of our repositioning approach. We also constructed a mode of action network for each candidate and performed pathway analysis for each candidate using genes contained in their mode of action network to uncover pathways that potentially reflect the mechanisms of candidates’ therapeutic efficacy to HF. We discovered numerous preliminary candidates, some of which are used in clinical practice and supported by the literature. The final candidates contained nearly all of the preliminary candidates supported by previous studies. Drug set enrichment analysis and literature search support the validity of our repositioning approach. The mode of action network for each candidate not only displayed the underlying mechanisms of drug efficacy but also uncovered potential biomarkers and therapeutic targets for HF. Our two-step drug repositioning approach is efficient to find candidates with potential therapeutic efficiency to HF supported by the literature and might be of particular use in the discovery of novel effective pharmacological therapies for HF.

Pyrrolidine Dithiocarbamate Attenuates Cardiocyte Apoptosis and Ameliorates Heart Failure Following Coronary Microembolization in Rats

Background

Nuclear factor-kB is highly activated in cardiovascular disorders. However, few articles have targeted at the role of nuclear factor-kB inhibitor in heart failure.

Aims

To evaluate the effects of nuclear factor-kB inhibitor pyrrolidine dithiocarbamate on cardiocyte apoptosis and cardiac function in a rat heart failure model.

Study Design

Animal experiment.

Methods

A stable and reproducible rat heart failure model (n=64) was prepared by injecting homologous microthrombotic particles into the left ventricle of Sprague–Dawley rats while obstructing the ascending aorta to produce coronary microembolization. Rats with heart failure were randomized into untreated (HFu) and pyrrolidine dithiocarbamate-treated (HFp) groups; the latter received an intraperitoneal injection of pyrrolidine dithiocarbamate (100 mg/kg/day) 1 h prior to surgery as well as on postoperative days 1-7. The sham group comprised 32 Sprague–Dawley rats. Eight rats from each group were sacrificed on days 1, 3, 7, and 14 postoperatively. Masson’s trichrome staining was used to determine the micro-fibrotic area to indicate the severity of myocardial loss. Terminal transferase uridine triphosphate nick end labeling staining was used to detect apoptotic cardiomyocytes. Echocardiography and hemodynamics were performed to evaluate left ventricular function.

Results

Rats with heart failure exhibited pathological changes evidenced by patchy myocardial fibrosis, remarkably elevated severity of myocardial loss, and persistently reduced left ventricular function. At the end of the study, compared with the HFu group, myocardial infarct size was reduced by 28% (p=0.001), cardiocyte apoptosis was suppressed (7.17%±1.47% vs 2.83%±0.75%, p<0.001), cardiac function parameters such as left ventricular ejection fraction (80%±4% vs 61%±6%), left ventricular + dP/dt max (4828±289 vs 2918±76 mmHg.s−1), left ventricular - dP/dt max (4398±269 vs 2481±365 mmHg.s−1), and left ventricular systolic pressure (126±13 vs 100±10 mmHg) were significantly increased, and left ventricular end-diastolic pressure was reduced (18±2 vs 13±1 mmHg) (p<0.001, for all) in the HFu group.

Conclusion

Our rat model can adequately mimic heart failure via coronary vessel embolization. Moreover, pyrrolidine dithiocarbamate treatment can reduce cardiocyte apoptosis and improve cardiac function, which may be beneficial for patients with heart failure secondary to myocardial infarction.

Immunometabolic cross-talk in the inflamed heart

Inflammatory processes underlie many diseases associated with injury of the heart muscle, including conditions without an obvious inflammatory pathogenic component such as hypertensive and diabetic cardiomyopathy. Persistence of cardiac inflammation can cause irreversible structural and functional deficits. Some are induced by direct damage of the heart muscle by cellular and soluble mediators but also by metabolic adaptations sustained by the inflammatory microenvironment. It is well established that both cardiomyocytes and immune cells undergo metabolic reprogramming in the site of inflammation, which allow them to deal with decreased availability of nutrients and oxygen. However, like in cancer, competition for nutrients and increased production of signalling metabolites such as lactate initiate a metabolic cross-talk between immune cells and cardiomyocytes which, we propose, might tip the balance between resolution of the inflammation versus adverse cardiac remodeling. Here we review our current understanding of the metabolic reprogramming of both heart tissue and immune cells during inflammation, and we discuss potential key mechanisms by which these metabolic responses intersect and influence each other and ultimately define the prognosis of the inflammatory process in the heart.

Zeaxanthin Isolated from Dunaliella salina Microalgae Ameliorates Age Associated Cardiac Dysfunction in Rats through Stimulation of Retinoid Receptors

Retinoids are essential during early cardiovascular morphogenesis. However, recent studies showed their important role in cardiac remodeling in rats with hypertension and following myocardial infarction. The present study aimed to investigate the effect of zeaxanthin heneicosylate (ZH); a carotenoid ester isolated from Dunaliella salina microalgae, on cardiac dysfunction ensuing d-galactose injection in rats. Rats injected with d-GAL (200 mg/kg; I.P) for 8 weeks were orally treated with ZH (250 μg/kg) for 28 consecutive days. Results showed that d-GAL injection caused dramatic electrocardiographic changes as well as marked elevation in serum levels of homocysteine, creatinine kinase isoenzyme and lactate dehydrogenase. A reduction in the cardiac contents of glucose transporter-4 and superoxide dismutase along with the elevation of inducible nitric oxide synthetase and interleukin-6 was also noticed. Oral administration of ZH significantly improved the above mentioned cardiac aging manifestations; this was further emphasized through histopathological examinations. The effect of ZH is mediated through the interaction with retinoid receptor alpha (RAR-α) as evidenced through a significant elevation of RAR-α expression in cardiac tissue following the lead of an in silico molecular docking study. In conclusion, zeaxanthin heneicosylate isolated from D. salina ameliorated age-associated cardiac dysfunction in rats through the activation of retinoid receptors.

Puerarin prevents diabetic cardiomyopathy in vivo and in vitro by inhibition of inflammation

Diabetic cardiomyopathy (DCM) is one of the chief diabetes mellitus complications. Inflammation factors may be one reason for the damage from DM. The purpose of this research is to study the potential protective effects of puerarin on DM and the possible mechanisms of action related to NF-κB signal pathway. Following administration of puerarin to the disease model rat, several changes were observed including the changes of serum biochemical index, improved diastolic dysfunction, and enhanced endogenous antioxidant enzymes activities, further NF-κB signaling activation. Puerarin showed cardio-protective effects on DCM by inhibiting inflammation, and it might be a potential candidate for the treatment of DCM.

NFkappaB is a Key Player in the Crosstalk between Inflammation and Cardiovascular Diseases

Inflammation is a key mechanism of cardiovascular diseases. It is an essential component of atherosclerosis and a significant risk factor for the development of cardiovascular events. In the crosstalk between inflammation and cardiovascular diseases, the transcription factor NFκB seems to be a key player since it is involved in the development and progression of both inflammation and cardiac and vascular damage. In this review, we deal with the recent findings of the role of inflammation in cardiac diseases, focusing, in particular, on NFκB as a functional link. We describe strategies for the therapeutic targeting of NFκB as a potential strategy for the failing heart.

Modification of gene expression in rat cardiomyocytes by linoleic and docosahexaenoic acids 1

Regulation of cardiac fatty acid metabolism is central to the development of cardiac hypertrophy and heart failure. We investigated the effects of select fatty acids on the expression of genes involved in immediate early as well as inflammatory and hypertrophic responses in adult rat cardiomyocytes. Cardiac remodeling begins with upregulation of immediate early genes for c-fos and c-jun, followed by upregulation of inflammatory genes for nuclear factor kappa B (NF-κB) and nuclear factor of activated T-cells (NFAT). At later stages, genes involved in hypertrophic responses, such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), are upregulated. Adult rat cardiomyocytes were treated with palmitic acid, a saturated fatty acid; oleic acid, a monounsaturated fatty acid; linoleic acid, a polyunsaturated fatty acid belonging to the n-6 class; and docosahexaenoic acid, a polyunsaturated fatty acid belonging to the n-3 class. Linoleic acid produced a greater increase in the mRNA expression of c-fos, c-jun, NF-κB, NFAT3, ANP, and BNP relative to palmitic acid and oleic acid. In contrast, docosahexaenoic acid caused a decrease in the expression of genes involved in cardiac hypertrophy. Our findings suggest that linoleic acid may be a potent inducer of genes involved in cardiac hypertrophy, whereas docosahexaenoic acid may be protective against the cardiomyocyte hypertrophic response.

Integrative analysis of competing endogenous RNA networks reveals the functional lncRNAs in heart failure

Heart failure has become one of the top causes of death worldwide. It is increasing evidence that lncRNAs play important roles in the pathology processes of multiple cardiovascular diseases. Additionally, lncRNAs can function as ceRNAs by sponging miRNAs to affect the expression level of mRNAs, implicating in numerous biological processes. However, the functional roles and regulatory mechanisms of lncRNAs in heart failure are still unclear. In our study, we constructed a heart failure-related lncRNA-mRNA network by integrating probe re-annotation pipeline and miRNA-target interactions. Firstly, some lncRNAs that had the central topological features were found in the heart failure-related lncRNA-mRNA network. Then, the lncRNA-associated functional modules were identified from the network, using bidirectional hierarchical clustering. Some lncRNAs that involved in modules were demonstrated to be enriched in many heart failure-related pathways. To investigate the role of lncRNA-associated ceRNA crosstalks in certain disease or physiological status, we further identified the lncRNA-associated dysregulated ceRNA interactions. And we also performed a random walk algorithm to identify more heart failure-related lncRNAs. All these lncRNAs were verified to show a strong diagnosis power for heart failure. These results will help us to understand the mechanism of lncRNAs in heart failure and provide novel lncRNAs as candidate diagnostic biomarkers or potential therapeutic targets.

CaMKIIδ interacts directly with IKKβ and modulates NF-κB signalling in adult cardiac fibroblasts

Calcium/calmodulin dependent protein kinase IIδ (CaMKIIδ) acts as a molecular switch regulating cardiovascular Ca²⁺ handling and contractility in health and disease. Activation of CaMKIIδ is also known to regulate cardiovascular inflammation and is reported to be required for pro-inflammatory NF-κB signalling. In this study the aim was to characterise how CaMKIIδ interacts with and modulates NF-κB signalling and whether this interaction exists in non-contractile cells of the heart. Recombinant or purified CaMKIIδ and the individual inhibitory -κB kinase (IKK) proteins of the NF-κB signalling pathway were used in autoradiography and Surface Plasmon Resonance (SPR) to explore potential interactions between both components. Primary adult rat cardiac fibroblasts were then used to study the effects of selective CaMKII inhibition on pharmacologically-induced NF-κB activation as well as interaction between CaMKII and specific IKK isoforms in a cardiac cellular setting. Autoradiography analysis suggested that CaMKIIδ phosphorylated IKKβ but not IKKα. SPR analysis further supported a direct interaction between CaMKIIδ and IKKβ but not between CaMKIIδ and IKKα or IKKγ. CaMKIIδ regulation of IκΒα degradation was explored in adult cardiac fibroblasts exposed to pharmacological stimulation. Cells were stimulated with agonist in the presence or absence of a CaMKII inhibitor, autocamtide inhibitory peptide (AIP). Selective inhibition of CaMKII resulted in reduced NF-κB activation, as measured by agonist-stimulated IκBα degradation. Importantly, and in agreement with the recombinant protein work, an interaction between CaMKII and IKKβ was evident following Proximity Ligation Assays in adult cardiac fibroblasts. This study provides new evidence supporting direct interaction between CaMKIIδ and IKKβ in pro-inflammatory signalling in cardiac fibroblasts and could represent a feature that may be exploited for therapeutic benefit.

Oleanonic acid ameliorates pressure overload-induced cardiac hypertrophy in rats: The role of PKCζ-NF-κB pathway

It has been reported that inflammation is closely related with cardiac hypertrophy. Some inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6 directly induce cardiac hypertrophy, which is associated with the activation of nuclear factorkappa B (NF-κB). Thus, NF-κB is an attractive target for cardiac hypertrophy. In the present study, oleanonic acid inhibited the elevation of transcriptional activity of NF-κB and reduced the mRNA expressions of hypertrophic genes such as atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) in a concentration-dependent manner in phenylephrine (PE)-treated cardiomyocytes. Furthermore, we found that oleanonic acid inhibited the phosphorylation of protein kinase C ζ (PKCζ) at Thr410 site and then reduced the activation of NF-κB using gain- and loss-of-function approaches in PE-treated cardiomyocytes. In vivo, similar results were observed in abdominal aortic constriction (AAC) rats that were intragastrically administered with oleanonic acid, and the pathological changes accompanying cardiac hypertrophy were relieved. In conclusion, oleanonic acid can effectively ameliorate cardiac hypertrophy by inhibiting PKCζ-NF-κB signaling pathway.

Methylsulfonylmethane decreases inflammatory response to tumor necrosis factor-α in cardiac cells

The development of various cardiovascular diseases (CVDs) are associated with chronic inflammation. Tumor necrosis factor α (TNF-α) is a pro-inflammatory cytokine that activates the nuclear factor-κB (NF-κB) signaling pathway, leading to increased inflammatory cytokine expression, such as interleukin-6 (IL-6). Interventions to reduce each of these factors have been demonstrated to reduce the development of CVD. Methylsulfonylmethane (MSM) is a naturally occurring compound that demonstrates anti-inflammatory effects in humans and various animal and cell culture models. The effects of MSM include decreased NF-κB activation, decreased expression of TNF-α, and IL-6. However, the effects of MSM within the heart have not yet been examined. Therefore, the purpose of this investigation was to determine whether MSM protects cardiac cells from inflammation that occurs in response to pro-inflammatory stimuli. A novel immortalized human ventricular cardiomyocyte cell line, designated Ac16, developed and characterized in the laboratory of Dr. Mercy Davidson, Columbia Invention Report No. 823, U.S. patent No. 7,223,599 were utilized. Cells were treated with TNF-α, alone or in combination with MSM. To confirm an appropriate dosage of MSM, the effect of various concentrations on cell viability, and IL-6 production were examined. The effect of MSM on transcript expression of pro-inflammatory markers and activation of NF-κB were examined with the established dose by real-time quantitative PCR and western blot, respectively. MSM treatment combined with TNF-α significantly decreased IL-6 production and transcript expression compared to TNF-α alone. These findings indicate that MSM may protect against inflammation in the heart, and thereby protect against inflammation-linked CVDs. Further study is warranted to determine the effect of MSM on cardiovascular health outcomes.

Inflammatory Mediators Drive Adverse Right Ventricular Remodeling and Dysfunction and Serve as Potential Biomarkers

Adverse right ventricular (RV) remodeling leads to ventricular dysfunction and failure that represents an important determinant of outcome in patients with pulmonary hypertension (PH). Recent evidence indicates that inflammatory activation contributes to the pathogenesis of adverse RV remodeling and dysfunction. It has been shown that accumulation of inflammatory cells such as macrophages and mast cells in the right ventricle is associated with maladaptive RV remodeling. In addition, inhibition of inflammation in animal models of RV failure ameliorated RV structural and functional impairment. Furthermore, a number of circulating inflammatory mediators have been demonstrated to be associated with RV performance. This work reviews the role of inflammation in RV remodeling and dysfunction and discusses anti-inflammatory strategies that may attenuate adverse structural alterations while promoting improvement of RV function.

G3BP2 is involved in isoproterenol-induced cardiac hypertrophy through activating the NF-κB signaling pathway

The RasGAP SH3 domain-binding proteins (G3BPs) are a family of RNA-binding proteins that can co-ordinate signal transduction and post-transcriptional gene regulation. G3BPs have been shown to be involved in mediating a great diversity of cellular processes such as cell survival, growth, proliferation and apoptosis. But the potential roles of G3BPs in the pathogenesis and progression of cardiovascular diseases remain to be clarified. In the present study, we provide the first evidence that suggests the participation of G3BP2 in cardiac hypertrophy. In cultured neonatal rat cardiomyocytes (NRCMs), treatment with isoproterenol (ISO, 0.1-100 μmol/L) significantly elevated the mRNA and protein levels of G3BP2. Similar results were observed in the hearts of rats subjected to 7D-injection of ISO, accompanied by obvious heart hypertrophy and elevated the expression of hypertrophy marker genes ANF, BNP and β-MHC in heart tissues. Overexpression of G3BP2 in NRCMs led to hypertrophic responses evidenced by increased cellular surface area and the expression of hypertrophy marker genes, whereas knockdown of G3BP2 significantly attenuated ISO-induced hypertrophy of NRCMs. We further showed that G3BP2 directly interacted with IκBα and promoted the aggregation of the NF-κB subunit p65 in the nucleus and increased NF-κB-dependent transcriptional activity. NF-κB inhibition with PDTC (50 μmol/L) or p65 knockdown significantly decreased the hypertrophic responses in NRCMs induced by ISO or G3BP2 overexpression. These results give new insight into the functions of G3BP2 and may help further elucidate the molecular mechanisms underlying cardiac hypertrophy.

Inhibition of myocardial hypertrophy by magnesium isoglycyrrhizinate through the TLR4/NF-κB signaling pathway in mice

Magnesium isoglycyrrhizinate (MgIG) is a magnesium salt of the 18-α glycyrrhizic acid stereoisomer that has exhibited hepato-protective effects and has anti-inflammatory, antioxidant, and antiviral activities. Here, we have investigated the effects and potential mechanisms of action of MgIG, with respect to myocardial fibrosis induced by isoproterenol (ISO) in mice. Mice were administered MgIG for 14days, with concurrent ISO dosing, and were sacrificed two weeks later. Lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations were measured in the blood. Pathological changes in the myocardium were observed via light microscopy. In addition, the expression of the Bax and Bcl-2 genes, and the basic fibroblast growth factor (bFGF) protein were measured via an immunohistochemical method. The RNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), c-fos, and c-jun mRNA were quantified by reverse transcription-polymerase chain reaction (RT-PCR) in the myocardial tissue. The protein expression of toll-like receptor (TLR) 4, and nuclear factor kappa B (NF-κB) (p65) were measured using Western blot assays. Compared with the control group, the ISO group showed significant increases in bFGF, Bax, Bcl-2, TLR4, and NF-κB (p65) expressions, as well as increased serum levels of LDH and CK. MgIG had a protective effect on ISO-induced myocardial fibrosis, which might be ascribed, at least in part, to the inhibition of the TLR4/NF-κB (p65) signaling pathway.

Lactacystin-Induced Model of Hypertension in Rats: Effects of Melatonin and Captopril

Lactacystin is a proteasome inhibitor that interferes with several factors involved in heart remodelling. The aim of this study was to investigate whether the chronic administration of lactacystin induces hypertension and heart remodelling and whether these changes can be modified by captopril or melatonin. In addition, the lactacystin-model was compared with NG-nitro-l-arginine-methyl ester (L-NAME)- and continuous light-induced hypertension. Six groups of three-month-old male Wistar rats (11 per group) were treated for six weeks as follows: control (vehicle), L-NAME (40 mg/kg/day), continuous light (24 h/day), lactacystin (5 mg/kg/day) alone, and lactacystin with captopril (100 mg/kg/day), or melatonin (10 mg/kg/day). Lactacystin treatment increased systolic blood pressure (SBP) and induced fibrosis of the left ventricle (LV), as observed in L-NAME-hypertension and continuous light-hypertension. LV weight and the cross-sectional area of the aorta were increased only in L-NAME-induced hypertension. The level of oxidative load was preserved or reduced in all three models of hypertension. Nitric oxide synthase (NOS) activity in the LV and kidney was unchanged in the lactacystin group. Nuclear factor-kappa B (NF-κB) protein expression in the LV was increased in all treated groups in the cytoplasm, however, in neither group in the nucleus. Although melatonin had no effect on SBP, only this indolamine (but not captopril) reduced the concentration of insoluble and total collagen in the LV and stimulated the NO-pathway in the lactacystin group. We conclude that chronic administration of lactacystin represents a novel model of hypertension with collagenous rebuilding of the LV, convenient for testing antihypertensive drugs or agents exerting a cardiovascular benefit beyond blood pressure reduction.

Effects of a Proteasome Inhibitor on Cardiomyocytes in a Pressure-Overload Hypertrophy Rat Model: An Animal Study

Background

The ubiquitin-proteasome system (UPS) is an important pathway of proteolysis in pathologic hypertrophic cardiomyocytes. We hypothesize that MG132, a proteasome inhibitor, might prevent hypertrophic cardiomyopathy (CMP) by blocking the UPS. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and androgen receptor (AR) have been reported to be mediators of CMP and heart failure. This study drew upon pathophysiologic studies and the analysis of NF-κB and AR to assess the cardioprotective effects of MG132 in a left ventricular hypertrophy (LVH) rat model.

Methods

We constructed a transverse aortic constriction (TAC)-induced LVH rat model with 3 groups: sham (TAC-sham, n=10), control (TAC-cont, n=10), and MG132 administration (TAC-MG132, n=10). MG-132 (0.1 mg/kg) was injected for 4 weeks in the TAC-MG132 group. Pathophysiologic evaluations were performed and the expression of AR and NF-κB was measured in the left ventricle.

Results

Fibrosis was prevalent in the pathologic examination of the TAC-cont model, and it was reduced in the TAC-MG132 group, although not significantly. Less expression of AR, but not NF-κB, was found in the TAC-MG132 group than in the TAC-cont group (p<0.05).

Conclusion

MG-132 was found to suppress AR in the TAC-CMP model by blocking the UPS, which reduced fibrosis. However, NF-κB expression levels were not related to UPS function.

Zinc Levels in Left Ventricular Hypertrophy

Zinc is one of the most important trace elements in the body and zinc homeostasis plays a critical role in maintaining cellular structure and function. Zinc dyshomeostasis can lead to many diseases, such as cardiovascular disease. Our aim was to investigate whether there is a relationship between zinc and left ventricular hypertrophy (LVH). A total of 519 patients was enrolled and their serum zinc levels were measured in this study. We performed analyses on the relationship between zinc levels and LVH and the four LV geometry pattern patients: normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH. We performed further linear and multiple regression analyses to confirm the relationship between zinc and left ventricular mass (LVM), left ventricular mass index (LVMI), and relative wall thickness (RWT). Our data showed that zinc levels were 710.2 ± 243.0 μg/L in the control group and were 641.9 ± 215.2 μg/L in LVH patients. We observed that zinc levels were 715 ± 243.5 μg/L, 694.2 ± 242.7 μg/L, 643.7 ± 225.0 μg/L, and 638.7 ± 197.0 μg/L in normal LV geometry, concentric remodeling, eccentric LVH, and concentric LVH patients, respectively. We further found that there was a significant inverse linear relationship between zinc and LVM (p = 0.001) and LVMI (p = 0.000) but did not show a significant relationship with RWT (p = 0.561). Multiple regression analyses confirmed that the linear relationship between zinc and LVM and LVMI remained inversely significant. The present study revealed that serum zinc levels were significantly decreased in the LVH patients, especially in the eccentric LVH and concentric LVH patients. Furthermore, zinc levels were significantly inversely correlated with LVM and LVMI.

Novel intracellular N-terminal truncated matrix metalloproteinase-2 isoform in skeletal muscle ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) occurs when blood returns to tissues following a period of ischemia. Reintroduction of blood flow results in the production of free radicals and reactive oxygen species that damage cells. Skeletal muscle IRI is commonly seen in orthopedic trauma patients. Experimental studies in other organ systems have elucidated the importance of extracellular and intracellular matrix metalloproteinase-2 (MMP-2) isoforms in regulating tissue damage in the setting of oxidant stress resulting from IRI. Although the extracellular full-length isoform of MMP-2 (FL-MMP-2) has been previously studied in the setting of skeletal muscle IRI, studies investigating the role of the N-terminal truncated isoform (NTT-MMP-2) in this setting are lacking. In this study, we first demonstrated significant increases in FL- and NTT-MMP-2 gene expression in C2C12 myoblast cells responding to re-oxygenation following hypoxia in vitro. We then evaluated the expression of FL- and NTT-MMP-2 in modulating skeletal muscle IRI using a previously validated murine model. NTT-MMP-2, but not FL-MMP-2 expression was significantly increased in skeletal muscle following IRI. Moreover, the expression of toll-like receptors (TLRs) -2 and -4, IL-6, OAS-1A, and CXCL1 was also significantly up-regulated following IRI. Treatment with the potent anti-oxidant pyrrolidine dithiocarbamate (PDTC) significantly suppressed NTT-MMP-2, but not FL-MMP-2 expression and improved muscle viability following IRI. This data suggests that NTT-MMP-2, but not FL-MMP-2, is the major isoform of MMP-2 involved in skeletal muscle IRI.

Asiatic acid inhibits cardiac hypertrophy by blocking interleukin-1β-activated nuclear factor-κB signaling in vitro and in vivo

BACKGROUND

Activated interleukin (IL)-1β signaling pathway is closely associated with pathological cardiac hypertrophy. This study investigated whether asiatic acid (AA) could inhibit IL-1β-related hypertrophic signaling, and thus suppressing the development of cardiac hypertrophy.

METHODS

Transverse aortic constriction (TAC) induced cardiac hypertrophy in C57BL/6 mice and cultured neonatal cardiac myocytes stimulated with IL-1β were used to evaluate the role of AA in cardiac hypertrophy. The expression of atrial natriuretic peptide (ANP) was evaluated by quantitative polymerase chain reaction (qPCR) and the nuclear factor (NF)-κB binding activity was measured by electrophoretic mobility shift assays (EMSA).

RESULTS

AA pretreatment significantly attenuated the IL-1β-induced hypertrophic response of cardiomyocytes as reflected by reduction in the cardiomyocyte surface area and the inhibition of ANP mRNA expression. The protective effect of AA on IL-1β-stimulated cardiomyocytes was associated with the reduction of NF-κB binding activity. In addition, AA prevented TAC-induced cardiac hypertrophy in vivo. It was found that AA markedly reduced the excessive expression of IL-1β and ANP, and inhibited the activation of NF-κB in the hypertrophic myocardium.

CONCLUSIONS

Our data suggest that AA may be a novel therapeutic agent for cardiac hypertrophy. The inhibition of IL-1β-activated NF-κB signaling may be the mechanism through which AA prevents cardiac hypertrophy.

Effects of cryptotanshinone on the expression levels of inflammatory factors in myocardial cells caused by Ang II and its mechanism

OBJECTIVE

This study aims to explore the effects of the traditional Chinese medicine monomer cryptotanshinone (CTS) on the expression levels of inflammatory factors in myocardial cells caused by Ang II and its mechanism.

METHODS

The neonatal rat myocardial cells were cultured in vitro in this study. Their purities were identified by immunocytochemical method. The cellular viability in different groups was determined by MTT assay. The levels of TNF-α and IL-6 in the supernatant of cell culture were detected with ELISA method. The levels of intracellular reactive oxygen species (ROS) were detected by Dihydrogen ethidium (DHE) staining method. The location changes of NF-κB in cells were detected by immunofluorescence method.

RESULTS

The purity of primary cultured neonatal rat myocardial cells was over 95%, CTS had no obvious effect on the viability of cells while it inhibited the increased levels of TNF-α, IL-6 and ROS caused by Ang II with dose dependent. NF-κB mainly distributed in the cytoplasmic region in normal cells, it translocated to the nucleus after Ang II stimulation while CTS inhibited the translocation.

CONCLUSIONS

CTS could inhibit the inflammatory factors such as TNF-α and IL-6 in myocardial cells induced by Ang II with dose dependent, its mechanism may be related with that CTS could decrease the levels of ROS in myocardial cells and inhibit NF-κB translocation into the nucleus.

Role of the calpain on the development of diabetes mellitus and its chronic complications

Diabetes mellitus (DM) is associated with acute and chronic complications that cause major morbidity and significant mortality. Calpains, a family of Ca(2+)-dependent cytosolic cysteine proteases, can modulate their substrates' structure and function through limited proteolytic activity. Calpain is a ubiquitous calcium-sensitive protease that is essential for normal physiologic function. However, alterations in calcium homeostasis lead to pathologic activation of calpain in diabetes mellitus. Since not much is known on the relationship between calpain and diabetes mellitus, this review outlines the contribution of calpain to chronic complications of diabetes mellitus, such as diabetic cardiomyopathy, diabetic nephropathy and diabetic retinopathy.