Leukocyte iNOS is required for inflammation and pathological remodeling in ischemic heart failure

Macrophage-mediated heart repair and remodeling: A promising therapeutic target for post-myocardial infarction heart failure

Heart failure (HF) remains prevalent in patients who survived myocardial infarction (MI). Despite the accessibility of the primary percutaneous coronary intervention and medications that alleviate ventricular remodeling with functional improvement, there is an urgent need for clinicians and basic scientists to further reveal the mechanisms behind post-MI HF as well as investigate earlier and more efficient treatment after MI. Growing numbers of studies have highlighted the crucial role of macrophages in cardiac repair and remodeling following MI, and timely intervention targeting the immune response via macrophages may represent a promising therapeutic avenue. Recently, technology such as single-cell sequencing has provided us with an updated and in-depth understanding of the role of macrophages in MI. Meanwhile, the development of biomaterials has made it possible for macrophage-targeted therapy. Thus, an overall and thorough understanding of the role of macrophages in post-MI HF and the current development status of macrophage-based therapy will assist in the further study and development of macrophage-targeted treatment for post-infarction cardiac remodeling. This review synthesizes the spatiotemporal dynamics, function, mechanism and signaling of macrophages in the process of HF after MI, as well as discusses the emerging bio-materials and possible therapeutic agents targeting macrophages for post-MI HF.

Myocardial Inflammation in Heart Failure With Reduced and Preserved Ejection Fraction

Heart failure (HF) is characterized by a progressive decline in cardiac function and represents one of the largest health burdens worldwide. Clinically, 2 major types of HF are distinguished based on the left ventricular ejection fraction (EF): HF with reduced EF and HF with preserved EF. While both types share several risk factors and features of adverse cardiac remodeling, unique hallmarks beyond ejection fraction that distinguish these etiologies also exist. These differences may explain the fact that approved therapies for HF with reduced EF are largely ineffective in patients suffering from HF with preserved EF. Improving our understanding of the distinct cellular and molecular mechanisms is crucial for the development of better treatment strategies. This article reviews the knowledge of the immunologic mechanisms underlying HF with reduced and preserved EF and discusses how the different immune profiles elicited may identify attractive therapeutic targets for these conditions. We review the literature on the reported mechanisms of adverse cardiac remodeling in HF with reduced and preserved EF, as well as the immune mechanisms involved. We discuss how the knowledge gained from preclinical models of the complex syndrome of HF as well as from clinical data obtained from patients may translate to a better understanding of HF and result in specific treatments for these conditions in humans.

Neutrophils are indispensable for adverse cardiac remodeling in heart failure

Persistent immune activation contributes significantly to left ventricular (LV) dysfunction and adverse remodeling in heart failure (HF). In contrast to their well-known essential role in acute myocardial infarction (MI) as first responders that clear dead cells and facilitate subsequent reparative macrophage polarization, the role of neutrophils in the pathobiology of chronic ischemic HF is poorly defined. To determine the importance of neutrophils in the progression of ischemic cardiomyopathy, we measured their production, levels, and activation in a mouse model of chronic HF 8 weeks after permanent coronary artery ligation and large MI. In HF mice, neutrophils were more abundant both locally in failing myocardium (more in the border zone) and systemically in the blood, spleen, and bone marrow, together with increased BM granulopoiesis. There were heightened stimuli for neutrophil recruitment and trafficking in HF, with increased myocardial expression of the neutrophil chemoattract chemokines CXCL1 and CXCL5, and increased neutrophil chemotactic factors in the circulation. HF neutrophil NETotic activity was increased in vitro with coordinate increases in circulating neutrophil extracellular traps (NETs) in vivo. Neutrophil depletion with either antibody-based or genetic approaches abrogated the progression of LV remodeling and fibrosis at both intermediate and late stages of HF. Moreover, analogous to murine HF, the plasma milieu in human acute decompensated HF strongly promoted neutrophil trafficking. Collectively, these results support a key tissue-injurious role for neutrophils and their associated cytotoxic products in ischemic cardiomyopathy and suggest that neutrophils are potential targets for therapeutic immunomodulation in this disease.

Thioredoxin-1 and its mimetic peptide improve systolic cardiac function and remodeling after myocardial infarction

Myocardial infarction (MI) is characterized by a significant loss of cardiomyocytes (CMs), and it is suggested that reactive oxygen species (ROS) are involved in cell cycle arrest, leading to impaired CM renewal. Thioredoxin-1 (Trx-1) scavenges ROS and may play a role in restoring CM renewal. However, the truncated form of Trx-1, Trx-80, can compromise its efficacy by exerting antagonistic effects. Therefore, a Trx-1 mimetic peptide called CB3 was tested as an alternative way to restore CMs. This study aimed to investigate the effects of Trx-1, Trx-80, and CB3 on mice with experimental MI and study the underlying mechanism of CB3 on CMs. Mouse cardiac parameters were quantified by echocardiography, and infarction size and fibrosis determined using Trichrome and Picro-Sirius Red staining. The study found that Trx-1 and CB3 improved mouse cardiac function, reduced the size of cardiac infarct and fibrosis, and decreased the expression of cardiac inflammatory markers. Furthermore, CB3 polarized macrophages into M2 phenotype, reduced apoptosis and oxidative stress after MI, and increased CM proliferation in cell culture and in vivo. CB3 effectively protected against myocardial infarction and could represent a new class of compounds for treating MI.

Inhibition of galectin-3 post-infarction impedes progressive fibrosis by regulating inflammatory profibrotic cascades

AIMS

Acute myocardial infarction (MI) causes inflammation, collagen deposition, and reparative fibrosis in response to myocyte death and, subsequently, a pathological myocardial remodelling process characterized by excessive interstitial fibrosis, driving heart failure (HF). Nonetheless, how or when to limit excessive fibrosis for therapeutic purposes remains uncertain. Galectin-3, a major mediator of organ fibrosis, promotes cardiac fibrosis and remodelling. We performed a preclinical assessment of a protein inhibitor of galectin-3 (its C-terminal domain, Gal-3C) to limit excessive fibrosis resulting from MI and prevent ventricular enlargement and HF.

METHODS AND RESULTS

Gal-3C was produced by enzymatic cleavage of full-length galectin-3 or by direct expression of the truncated form in Escherichia coli. Gal-3C was intravenously administered for 7 days in acute MI models of young and aged rats, starting either pre-MI or 4 days post-MI. Echocardiography, haemodynamics, histology, and molecular and cellular analyses were performed to assess post-MI cardiac functionality and pathological fibrotic progression. Gal-3C profoundly benefitted left ventricular ejection fraction, end-systolic and end-diastolic volumes, haemodynamic parameters, infarct scar size, and interstitial fibrosis, with better therapeutic efficacy than losartan and spironolactone monotherapies over the 56-day study. Gal-3C therapy in post-MI aged rats substantially improved pump function and attenuated ventricular dilation, preventing progressive HF. Gal-3C in vitro treatment of M2-polarized macrophage-like cells reduced their M2-phenotypic expression of arginase-1 and interleukin-10. Gal-3C inhibited M2 polarization of cardiac macrophages during reparative response post-MI. Gal-3C impeded progressive fibrosis post-MI by down-regulating galectin-3-mediated profibrotic signalling cascades including a reduction in endogenous arginase-1 and inducible nitric oxide synthase (iNOS).

CONCLUSION

Gal-3C treatment improved long-term cardiac function post-MI by reduction in the wound-healing response, and inhibition of inflammatory fibrogenic signalling to avert an augmentation of fibrosis in the periinfarct region. Thus, Gal-3C treatment prevented the infarcted heart from extensive fibrosis that accelerates the development of HF, providing a potential targeted therapy.

An ischemic area-targeting, peroxynitrite-responsive, biomimetic carbon monoxide nanogenerator for preventing myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (MI/R) injury is common in patients who undergo revascularization therapy for myocardial infarction, often leading to cardiac dysfunction. Carbon monoxide (CO) has emerged as a therapeutic molecule due to its beneficial properties such as anti-inflammatory, anti-apoptotic, and mitochondrial biogenesis-promoting properties. However, its clinical application is limited due to uncontrolled release, potential toxicity, and poor targeting efficiency. To address these limitations, a peroxynitrite (ONOO^-)-triggered CO donor (PCOD585) is utilized to generate a poly (lactic-co-glycolic acid) (PLGA)-based, biomimetic CO nanogenerator (M/PCOD@PLGA) that is coated with the macrophage membrane, which could target to the ischemic area and neutralize proinflammatory cytokines. In the ischemic area, local produced ONOO^- triggers the continuous release of CO from M/PCOD@PLGA, which efficiently ameliorates MI/R injury by clearing harmful ONOO^-, attenuating the inflammatory response, inhibiting cardiomyocyte apoptosis, and promoting mitochondrial biogenesis. This study provides a novel insight into the safe therapeutic use of CO for MI/R injury by utilizing a novel CO donor combined with biomimetic technology. The M/PCOD@PLGA nanogenerator offers targeted delivery of CO to the ischemic area, minimizing potential toxicity and enhancing therapeutic efficacy.

Assessment of Squalene-Adenosine Nanoparticles in Two Rodent Models of Cardiac Ischemia-Reperfusion

Reperfusion injuries after a period of cardiac ischemia are known to lead to pathological modifications or even death. Among the different therapeutic options proposed, adenosine, a small molecule with platelet anti-aggregate and anti-inflammatory properties, has shown encouraging results in clinical trials. However, its clinical use is severely limited because of its very short half-life in the bloodstream. To overcome this limitation, we have proposed a strategy to encapsulate adenosine in squalene-based nanoparticles (NPs), a biocompatible and biodegradable lipid. Thus, the aim of this study was to assess, whether squalene-based nanoparticles loaded with adenosine (SQAd NPs) were cardioprotective in a preclinical cardiac ischemia/reperfusion model. Obtained SQAd NPs were characterized in depth and further evaluated in vitro. The NPs were formulated with a size of about 90 nm and remained stable up to 14 days at both 4 °C and room temperature. Moreover, these NPs did not show any signs of toxicity, neither on HL-1, H9c2 cardiac cell lines, nor on human PBMC and, further retained their inhibitory platelet aggregation properties. In a mouse model with experimental cardiac ischemia-reperfusion, treatment with SQAd NPs showed a reduction of the area at risk, as well as of the infarct area, although not statistically significant. However, we noted a significant reduction of apoptotic cells on cardiac tissue from animals treated with the NPs. Further studies would be interesting to understand how and through which mechanisms these nanoparticles act on cardiac cells.

Chemotactic NO/H2S Nanomotors Realizing Cardiac Targeting of G-CSF against Myocardial Ischemia-Reperfusion Injury

Recombinant granulocyte colony-stimulating factor (G-CSF), with a direct repair effect on injured cardiomyocytes against myocardial infarction ischemia-reperfusion-injury (IRI), displays a poor effect owing to the limited cardiac targeting efficacy. There are almost no reports of nanomaterials that deliver G-CSF to the IRI site. Herein, we propose a way to protect G-CSF by constructing one layer of nitric oxide (NO)/hydrogen sulfide (H₂S) nanomotors on its outside. NO/H₂S nanomotors with specific chemotactic ability to high expression of reactive oxygen species (ROS)/induced nitric oxide synthase (iNOS) at the IRI site can deliver G-CSF to the IRI site efficiently. Meanwhile, superoxide dismutase is covalently bound to the outermost part, reducing ROS at the IRI site through a cascade effect with NO/H₂S nanomotors. The synergistic effect between NO and H₂S on the effective regulation of the IRI microenvironment can not only avoid toxicity caused by excessive concentration of a single gas but also reduce inflammation level and relieve calcium overload, so as to promote G-CSF to play a cardioprotective role.

Polygonum orientale L. Alleviates Myocardial Ischemia-Induced Injury via Activation of MAPK/ERK Signaling Pathway

Although Polygonum orientale L. (PO) has a beneficial effect on treatment of myocardial ischemia (MI), its mechanism remains unclear. This study aimed to explore the pharmacological mechanism of PO against MI through MAPK signaling pathways. Firstly, the therapeutic effect of PO was evaluated for treatment of MI mice. Using Western blot and immunohistochemistry, the influence of PO on MAPK signaling pathways and cell apoptosis was investigated. Subsequently, one key pathway (ERK) of MAPK signaling pathways was screened out, on which PO posed the most obvious impact. Finally, an inhibitor of ERK1/2 was utilized to further verify the regulatory effect of PO on the MAPK/ERK signaling pathway. It was found that PO could reduce the elevation of the ST segment; injury of heart tissue; the activity of LDH, CK, NOS, cNOS and iNOS and the levels of NO, BNP, TNF-α and IL-6. It is notable that PO could significantly modulate the protein content of p-ERK/ERK in mice suffering from MI but hardly had an effect on p-JNK/JNK and p-p38/p38. Additionally, the expressions of bax, caspase3 and caspase9 were inhibited in heart tissue in the PO-treated group. To evaluate whether ERK1/2 inhibitor (PD98059) could block the effect of PO on treatment of MI, both PO and PD98059 were given to mice with MI. It was discovered that the inhibitor indeed could significantly reverse the regulatory effects of PO on the above indicators, indicating that PO could regulate p-ERK/ERK. This study provides experimental evidence that PO extenuates MI injury, cardiomyocyte apoptosis and inflammation by activating the MAPK/ERK signaling pathway.

Untargeted metabolomic analysis of ischemic injury in human umbilical vein endothelial cells reveals the involvement of arginine metabolism

OBJECTIVE

In this study, differentially expressed metabolites of vascular endothelial cells were examined to further understand the metabolic regulation of ischemic injury by untargeted metabolomics.

METHOD

Human umbilical vein endothelial cells (HUVECs) were selected to construct an ischemia model using oxygen-glucose deprivation (OGD) and 0, 3, 6, and 9 h of treatment. After that, cell survival levels were determined by CCK8 detection. Flow cytometry, ROS detection, JC-1 detection, and western blotting were used to measure apoptosis and oxidative stress in cells. Then, combined with UPLC Orbitrap/MS, we verified the impacted metabolism pathways by western blotting and RT‒PCR.

RESULTS

CCK8 assays showed that the survival of HUVECs was decreased with OGD treatment. Flow cytometry and the expression of cleaved caspase 3 showed that the apoptosis levels of HUVECs increased following OGD treatment. The ROS and JC-1 results further suggested that oxidative stress injury was aggravated. Then, combined with the heatmap, KEGG and IPA, we found that arginine metabolism was differentially altered during different periods of OGD treatment. Furthermore, the expression of four arginine metabolism-related proteins, ASS1, ARG2, ODC1 and SAT1, was found to change during treatment.

CONCLUSION

Arginine metabolism pathway-related proteins were significantly altered by OGD treatment, which suggests that they may have a potential role in ischemic injury.

Molecular Mechanisms of Mitochondrial Quality Control in Ischemic Cardiomyopathy

Ischemic cardiomyopathy (ICM) is a special type of coronary heart disease or an advanced stage of the disease, which is related to the pathological mechanism of primary dilated cardiomyopathy. Ischemic cardiomyopathy mainly occurs in the long-term myocardial ischemia, resulting in diffuse myocardial fibrosis. This in turn affects the cardiac ejection function, resulting in a significant impact on myocardial systolic and diastolic function, resulting in a decrease in the cardiac ejection fraction. The pathogenesis of ICM is closely related to coronary heart disease. Mainly due to coronary atherosclerosis caused by coronary stenosis or vascular occlusion, causing vascular inflammatory lesions and thrombosis. As the disease progresses, it leads to long-term myocardial ischemia and eventually ICM. The pathological mechanism is mainly related to the mechanisms of inflammation, myocardial hypertrophy, fibrosis and vascular remodeling. Mitochondria are organelles with a double-membrane structure, so the composition of the mitochondrial outer compartment is basically similar to that of the cytoplasm. When ischemia-reperfusion induces a large influx of calcium into the cell, the concentration of calcium ions in the mitochondrial outer compartment also increases. The subsequent opening of the membrane permeability transition pore in the inner mitochondrial membrane and the resulting calcium overload induces the homeostasis of cardiomyocytes and activates the mitochondrial pathway of apoptosis. Mitochondrial Quality Control (MQC), as an important mechanism for regulating mitochondrial function in cardiomyocytes, affects the morphological structure/function and lifespan of mitochondria. In this review, we discuss the role of MQC (including mitophagy, mitochondrial dynamics, and mitochondrial biosynthesis) in the pathogenesis of ICM and provide important evidence for targeting MQC for ICM.

Qishen Granule (QSG) Inhibits Monocytes Released From the Spleen and Protect Myocardial Function via the TLR4-MyD88-NF-κB p65 Pathway in Heart Failure Mice

Preliminary clinical and basic researches have proved that Qishen granule (QSG) is an effective prescription for treating heart failure (HF) in China, with a characteristic of regulating the ratio of M1/M2 macrophage in the myocardium. However, the regulative mechanism of monocytes targeting the cardio-splenic axis has not been fully elucidated. This study aimed to investigate the effects and mechanism of QSG inhibiting the release of splenic monocytes and the recruitment of myocardial tissue both in vivo and in vitro. Experiments in mice with acute myocardial infarction (AMI)-induced HF demonstrated that QSG could exert anti-inflammatory effects by inhibiting splenic monocytes release and phenotypic changes. Moreover, in vitro experiments indicated QSG could inhibit LPS-stimulated macrophage-conditioned medium (CM)-induced H9C2 cardiomyocyte injury by upregulating the key proteins in TLR4-MyD88-NF-κB p65 pathway. In addition, knockdown or overexpression of TLR4 in H9C2 cells further confirmed that QSG could attenuate inflammatory injury in cardiomyocytes via the TLR4-MyD88-NF-κB p65 pathway. Overall, these data suggested that QSG could improve cardiac function and reduce the inflammatory response in AMI-induced HF by inhibiting splenic monocytes release, and protecting myocardial function via the TLR4-MyD88-NF-κB pathway in heart failure mice.

Nanoparticles Targeting the Molecular Pathways of Heart Remodeling and Regeneration

Cardiovascular diseases are the main cause of death worldwide, a trend that will continue to grow over the next decade. The heart consists of a complex cellular network based mainly on cardiomyocytes, but also on endothelial cells, smooth muscle cells, fibroblasts, and pericytes, which closely communicate through paracrine factors and direct contact. These interactions serve as valuable targets in understanding the phenomenon of heart remodeling and regeneration. The advances in nanomedicine in the controlled delivery of active pharmacological agents are remarkable and may provide substantial contribution to the treatment of heart diseases. This review aims to summarize the main mechanisms involved in cardiac remodeling and regeneration and how they have been applied in nanomedicine.

Tetramethylpyrazine Improves Monocrotaline-Induced Pulmonary Hypertension through the ROS/iNOS/PKG-1 Axis

Background

Tetramethylpyrazine (TMP), a potent anti-free radical and anti-inflammations substance, has been demonstrated to possess a direct vessel relaxation property. This study aimed to evaluate the effect of TMP treatment in pulmonary hypertension (PH) and test the hypothesis that TMP prevents or reverses the process of PH.

Methods

Rats (n = 36) injected with 50 mg/kg of monocrotaline (MCT) subcutaneously 4 weeks to develop PH were then randomized to TMP (5 mg/kg per day) for another 4 weeks. Hemodynamics was evaluated via the right ventricle. Pulmonary vessels structural remodeling and inflammation were examined by histologic and transmission electron microscopy observation. The expression of inducible nitric oxide synthase (iNOS) and cGMP-dependent protein kinases 1 (PKG-1) was detected by immunohistochemical staining and Western blot. Generation of reactive oxygen species (ROS) and antioxidation species was measured by biochemical analyses.

Results

MCT increased PH and right ventricle hypertrophy. TMP alleviated pulmonary arterial pressure elevation, leukocyte infiltration, and structural remodeling of pulmonary arterials induced by MCT successfully. TMP treatment significantly increased the PKG-1 expression and suppressed the iNOS expression. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH), and catalase (CAT) was significantly higher than control group, while malondialdehyde (MDA) levels were lower compared with MCT group.

Conclusion

TMP can suppress established MCT-induced PH through the ROS/iNOS/PKG axis. The underlying mechanisms may be associated with its anti-inflammatory, antioxidant, and antiproliferative properties in pulmonary arterial.

Metabolism of tissue macrophages in homeostasis and pathology

Cellular metabolism orchestrates the intricate use of tissue fuels for catabolism and anabolism to generate cellular energy and structural components. The emerging field of immunometabolism highlights the importance of cellular metabolism for the maintenance and activities of immune cells. Macrophages are embryo- or adult bone marrow-derived leukocytes that are key for healthy tissue homeostasis but can also contribute to pathologies such as metabolic syndrome, atherosclerosis, fibrosis or cancer. Macrophage metabolism has largely been studied in vitro. However, different organs contain diverse macrophage populations that specialize in distinct and often tissue-specific functions. This context specificity creates diverging metabolic challenges for tissue macrophage populations to fulfill their homeostatic roles in their particular microenvironment and conditions their response in pathological conditions. Here, we outline current knowledge on the metabolic requirements and adaptations of macrophages located in tissues during homeostasis and selected diseases.

Catalpol alleviates myocardial ischemia reperfusion injury by activating the Nrf2/HO-1 signaling pathway

PURPOSE

Myocardial ischemia/reperfusion injury (MI/RI) is a major problem in the clinical treatment of ischemic cardiomyopathy, and its specific underlying mechanisms are complicated and still unclear. A number of studies have indicated that the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxidase-1(HO-1) signaling pathway might serve as an important target for the management of MI/RI. Catalpol is a kind of iridoid glucoside that has been found to exhibit diverse anti-inflammatory and antioxidant properties. This study was aimed at investigating the role of Catalpol in targeting MI/RI and its related mechanisms in an oxygen-glucose deprivation/reoxygenation (OGD/R) model in vitro and a preclinical ischemia/reperfusion (I/R) model.

METHODS

This study using both in vitro and in vivo models investigated the possible role and underlying mechanisms used by Catalpol for modulating of MI/RI. The potential effects of Catalpol on the viability of cardiomyocytes were measured by cell counting kit-8 (CCK-8) assays. The phenotypes of myocardial injury, oxidative stress and inflammation markers were measured by western blot, immunofluorescence, enzyme-linked immunosorbent assay (ELISA) etc. Nrf2/HO-1 signaling pathway was detected by immunofluorescence and western blot analysis.

RESULTS

We found that Catalpol significantly suppressed the process of MI/RI and protected OGD/R-treated cardiomyocytes by inhibiting the various markers of inflammation and suppressing oxidative stress. Additionally, mechanistically it was also demonstrated that Catalpol could effectively activate Nrf2/HO-1 signaling pathway to suppress the damage caused by inflammation and oxidative stress in MI/RI.

CONCLUSION

In summary, the findings suggest that Catalpol exerted significant cardioprotective effects following myocardial ischemia, possibly through the activation of the Nrf2/HO-1 signaling pathway.

Targeting Rac1 for the prevention of atherosclerosis among U.S. Veterans with inflammatory bowel disease

Evidence suggests that Ras-related C3 botulinum toxin substrate 1 (Rac1) might be a target in atherosclerotic disease (AD). We hypothesize that due to their ability to inhibit Rac1, thiopurines are associated with a lower risk of AD. We fit a time-dependent cox proportional hazards model estimating the hazard of AD among a national cohort of US veterans with inflammatory bowel disease. Patients exposed to thiopurines had a 7.5% lower risk of AD (HR = 0.925; 95% CI = (0.87-0.984)) compared to controls. The propensity score weighted analysis reveals thiopurine exposure reduces the risk of AD by 6.6% (HR = 0.934; 95% CI = (0.896-0.975)), compared to controls. Further exploration and evaluation of Rac1 inhibition as a target for AD is warranted.

Control of Tissue Fibrosis by 5-Methoxytryptophan, an Innate Anti-Inflammatory Metabolite

Tissue fibrosis causes debilitating human diseases such as liver cirrhosis, heart failure, chronic kidney disease and pulmonary insufficiency. It is a dynamic process orchestrated by specific subsets of monocyte-macrophages, fibroblasts, pericytes and hepatic stellate cells. Fibrosis is linked to tissue inflammation. Pro-inflammatory macrophages promote fibrosis by driving myofibroblast differentiation and macrophage myofibroblast transition. Myofibroblasts express α-smooth muscle cell actin (α-SMA) and secrete extracellular matrix (ECM) proteins notably collagen I and III. Deposition of ECM proteins at injury sites and interstitial tissues distorts normal structure and impairs vital functions. Despite advances in the mechanisms of fibrosis at cellular, molecular and genetic levels, prevention and treatment of fibrotic diseases remain poorly developed. Recent reports suggest that 5-methoxytryptophan (5-MTP) is effective in attenuating injury-induced liver, kidney, cardiac and pulmonary fibrosis. It inhibits macrophage activation and blocks fibroblast differentiation to myofibroblasts. Furthermore, it inhibits hepatic stellate cell differentiation into myofibroblasts. As 5-MTP is an endogenous molecule derived from tryptophan catabolism via tryptophan hydroxylase pathway, it is well-suited as a lead compound for developing new anti-fibrotic drugs. This article provides an overview of 5-MTP synthesis, and a critical review of its anti-fibrotic activities. Its mechanisms of actions and potential therapeutic value will be discussed.

Cardiac inflammation and fibrosis following chemo/radiation therapy: mechanisms and therapeutic agents

The incidence of cardiovascular disorders is one of the most concerns among people who underwent cancer therapy. The heart side effects of cancer therapy may occur during treatment to some years after the end of treatment. Some epidemiological studies confirm that heart diseases are one of the most common reasons for mortality among patients that were received treatment for cancer. Experimental studies and also clinical investigations indicate that inflammatory changes such as pericarditis, myocarditis, and also fibrosis are key mechanisms of cardiac diseases following chemotherapy/radiotherapy. It seems that chronic oxidative stress, massive cell death, and chronic overproduction of pro-inflammatory and pro-fibrosis cytokines are the key mechanisms of cardiovascular diseases following cancer therapy. Furthermore, infiltration of inflammatory cells and upregulation of some enzymes such as NADPH Oxidases are a hallmark of heart diseases after cancer therapy. In the current review, we aim to explain how radiation or chemotherapy can induce inflammatory and fibrosis-related diseases in the heart. We will explain the cellular and molecular mechanisms of cardiac inflammation and fibrosis following chemo/radiation therapy, and then review some adjuvants to reduce the risk of inflammation and fibrosis in the heart.

Inflammation in Human Heart Failure: Major Mediators and Therapeutic Targets

Inflammation has been recognized as a major pathophysiological contributor to the entire spectrum of human heart failure (HF), including HF with reduced ejection fraction, HF with preserved ejection fraction, acute HF and cardiogenic shock. Nevertheless, the results of several trials attempting anti-inflammatory strategies in HF patients have not been consistent or motivating and the clinical implementation of anti-inflammatory treatments for HF still requires larger and longer trials, as well as novel and/or more specific drugs. The present work reviews the different inflammatory mechanisms contributing to each type of HF, the major inflammatory mediators involved, namely tumor necrosis factor alpha, the interleukins 1, 6, 8, 10, 18, and 33, C-reactive protein and the enzymes myeloperoxidase and inducible nitric oxide synthase, and their effects on heart function. Furthermore, several trials targeting these mediators or involving other anti-inflammatory treatments in human HF are also described and analyzed. Future therapeutic advances will likely involve tailored anti-inflammatory treatments according to the patient's inflammatory profile, as well as the development of resolution pharmacology aimed at stimulating resolution of inflammation pathways in HF.

Reactive oxygen species-based nanomaterials for the treatment of myocardial ischemia reperfusion injuries

Interventional coronary reperfusion strategies are widely adopted to treat acute myocardial infarction, but morbidity and mortality of acute myocardial infarction are still high. Reperfusion injuries are inevitable due to the generation of reactive oxygen species (ROS) and apoptosis of cardiac muscle cells. However, many antioxidant and anti-inflammatory drugs are largely limited by pharmacokinetics and route of administration, such as short half-life, low stability, low bioavailability, and side effects for treatment myocardial ischemia reperfusion injury. Therefore, it is necessary to develop effective drugs and technologies to address this issue. Fortunately, nanotherapies have demonstrated great opportunities for treating myocardial ischemia reperfusion injury. Compared with traditional drugs, nanodrugs can effectively increase the therapeutic effect and reduces side effects by improving pharmacokinetic and pharmacodynamic properties due to nanodrugs’ size, shape, and material characteristics. In this review, the biology of ROS and molecular mechanisms of myocardial ischemia reperfusion injury are discussed. Furthermore, we summarized the applications of ROS-based nanoparticles, highlighting the latest achievements of nanotechnology researches for the treatment of myocardial ischemia reperfusion injury.

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Cardiovascular diseases are the leading cause of death worldwide. Researches of the myocardial infarction pathology and development of new treatments have very important scientific significance in the biomedical field.

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Many nanomaterials have shown amazing therapeutic effects to reduce myocardial damage by eliminating ROS.

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Nanomaterials effectively reduced myocardial damage through eliminating ROS from NOXs, M-ETC, M-Ca²⁺, M-mPTP, and RIRR.

The ameliorative effect of N-acetylcysteine against penconazole induced neurodegenerative and neuroinflammatory disorders in rats

Penconazole (PEN) is a widely used systemic fungicide to treat various fungal diseases in plants but it leaves residues in crops and food products causing serious environmental and health problems. N-acetylcysteine (NAC) is a precursor of the antioxidant glutathione in the body and exerts prominent antioxidant and anti-inflammatory effects. The present study aimed to explore the mechanistic way of NAC to ameliorate the PEN neurotoxicity in male rats. Twenty-eight male rats were randomly divided into four groups (n = 7) and given the treated material via oral gavage for 10 days as the following: Group I (distilled water), Group II (50 mg/kg body weight [bwt] PEN), Group III (200 mg/kg bwt NAC), and Group IV (NAC + PEN). After 10 days all rats were subjected to behavioral assessment and then euthanized to collect brain tissues to perform oxidative stress, molecular studies, and pathological examination. Our results revealed that PEN exhibits neurobehavioral toxicity manifested by alteration in the forced swim test, elevated plus maze test, and Y-maze test. There were marked elevations in malondialdehyde levels with reduction in total antioxidant capacity levels, upregulation of messenger RNA levels of bax, caspase 3, and caspase 9 genes with downregulation of bcl2 genes. In addition, brain sections showed marked histopathological alteration in the cerebrum and cerebellum with strong bax and inducible nitric oxide synthetase protein expression. On the contrary, cotreatment of rats with NAC had the ability to improve all the abovementioned neurotoxic parameters. The present study can conclude that NAC has a neuroprotective effect against PEN-induced neurotoxicity via its antioxidant, anti-inflammatory, and antiapoptotic effect. We recommend using NAC as a preventive and therapeutic agent for a wide variety of neurodegenerative and neuroinflammatory disorders.

The role of anti-inflammatory drugs and nanoparticle-based drug delivery models in the management of ischemia-induced heart failure

Ongoing advancements in the treatment of acute myocardial infarction (MI) have significantly decreased MI related mortality. Consequently, the number of patients experiencing post-MI heart failure (HF) has continued to rise. Infarction size and the extent of left ventricular (LV) remodeling are largely determined by the extent of ischemia at the time of myocardial injury. In the setting of MI or acute phase of post-MI LV remodeling, anti-inflammatory drugs including intravenous immunoglobulin (IVIG) and Pentoxifylline have shown potential efficacy in preventing post-MI remodeling in-vitro and in some clinical trials. However, systemic administration of anti-inflammatory drugs are not without their off-target side effects. Herein, we explore the clinical feasibility of targeted myocardial delivery of anti-inflammatory drugs via biodegradable polymers, liposomes, hydrogels, and nano-particle based drug delivery models (NDDM) based on existing pre-clinical and clinical models. We summarize the barriers to clinical application of targeted anti-inflammatory delivery post-MI, including challenges in achieving sufficient retention and distribution, as well as the potential need for multiple dosing. Collectively, we suggest that localized delivery of anti-inflammatory agents to the myocardium using NDDM is a promising approach for successful treatment of ischemic HF. Future studies will be instrumental in determining the most effective target and delivery modalities for orchestrating NDDM-mediated treatment of HF.

5-Methoxytryptophan attenuates postinfarct cardiac injury by controlling oxidative stress and immune activation

AIMS

Myocardial infarction (MI) remains a major cause of heart failure. 5-Methoxytryptophan (5-MTP), a 5-methoxyindole metabolite of L-tryptophan, exerts anti-inflammatory and antifibrotic effects, but MI impairs the biosynthesis of cardiac 5-MTP. Therefore, we evaluated the effect of exogenous 5-MTP administration on rescuing post-MI cardiac injury.

METHODS AND RESULTS

After a detailed pharmacokinetic analysis of 5-MTP, Sprague Dawley rats that had undergone left anterior descending coronary artery ligation received intraperitoneal administration of either 17 mg/kg 5-MTP or saline at 0.5 and 24 h after MI. Cardiac systolic function, infarction size, and fibrosis were evaluated using echocardiography, triphenyltetrazolium chloride staining, and Masson trichrome staining, respectively. Myocardial apoptosis was analyzed by staining for caspase-3 and cardiac troponin I. 5-MTP treatment decreased the infarct area and myocardial apoptosis; attenuated systolic dysfunction and left ventricular dilatation; and reduced cardiomyocyte hypertrophy, myocardial fibrosis, and infarct expansion. Crucially, 5-MTP alleviated oxidative stress by preserving mitochondrial antioxidant enzymes and downregulating reactive oxygen species-generating NADPH oxidase isoforms and endothelin-1. Consequently, 5-MTP-treated MI rat hearts exhibited lower levels of chemokines and cytokines, namely interleukin (IL)-1β, IL-18, IL-6, C-C motif chemokine ligand (CCL)-2, and CCL5, accompanied by reduced infiltration of CD11b⁺ cells and CD4⁺ T cells. Notably, 5-MTP protected against H₂O₂-induced damage in HL-1 cardiomyocytes and human umbilical vein endothelial cells in vitro.

CONCLUSION

5-MTP prevented post-MI cardiac injury by promoting mitochondrial stabilization and controlling redox imbalance. This cytoprotective effect ameliorated macrophage and T-cell infiltration, thus reducing the infarct size, attenuating fibrosis, and restoring myocardial function.

Regular aerobic exercise activates PDGF-BB/PDGFR-β signaling and modulates the inflammatory-anti-inflammatory balance in diet-induced obese mice

OBJECTIVE

Regular aerobic exercise induces cardioprotection by counteracting the obesity-associated inflammatory response, dyslipidemia. PDGF-BB/PDGFR-β signaling is established as a crucial mechanism of endothelial cell-cardiomyocyte communication and cardioprotection, but its physiological roles in response to obesity and regular aerobic exercise are unknown.

METHODS

Thirty C57BL/6 mice were divided into three groups: a normal diet group, a high-fat diet group, and a high-fat diet plus aerobic exercise group. Glucose metabolic parameters, inflammation-related indicators, and blood lipids indicators were detected. In addition, gene expression levels of the inflammatory factors, PDGF-BB, PDGFR-β, PI3K, Akt, eNOS, and P53 in cardiac tissue were quantified. Morphological analysis was also used to quantify the magnitude of inflammation.

RESULTS

High-fat diet (HFD) feeding resulted in adiposity, dyslipidemia, and low levels of cardioprotective factors such as APN and eNOS (P < 0.05), which were improved significantly by 8 weeks of aerobic exercise (P < 0.05). HFD feeding increased the gene expression levels of proinflammatory cytokines and decreased the gene expression levels of anti-inflammatory cytokines in cardiac tissue (P < 0.05), which was reversed by regular aerobic exercise (P < 0.05). In addition, HFD feeding suppressed the levels of the cardioprotective factors PDGF-BB and eNOS through PDGF-BB/PDGFR-β/PI3K/Akt/eNOS signaling in cardiac tissue, while regular aerobic exercise activated PDGF-BB/PDGFR-β/PI3K/Akt/eNOS signaling.

CONCLUSION

Regular aerobic exercise improved adiposity, dyslipidemia induced by HFD feeding. Regular aerobic exercise exerted a prominent role in modulating the inflammatory-anti-inflammatory balance and activating the levels of the cardioprotective factors eNOS and PDGF-BB through PDGF-BB/PDGFR-β signaling.

Fundamental Mechanisms of the Cell Death Caused by Nitrosative Stress

Nitrosative stress, as an important oxygen metabolism disorder, has been shown to be closely associated with cardiovascular diseases, such as myocardial ischemia/reperfusion injury, aortic aneurysm, heart failure, hypertension, and atherosclerosis. Nitrosative stress refers to the joint biochemical reactions of nitric oxide (NO) and superoxide (O₂ ^-) when an oxygen metabolism disorder occurs in the body. The peroxynitrite anion (ONOO^-) produced during this process can nitrate several biomolecules, such as proteins, lipids, and DNA, to generate 3-nitrotyrosine (3-NT), which further induces cell death. Among these, protein tyrosine nitration and polyunsaturated fatty acid nitration are the most studied types to date. Accordingly, an in-depth study of the relationship between nitrosative stress and cell death has important practical significance for revealing the pathogenesis and strategies for prevention and treatment of various diseases, particularly cardiovascular diseases. Here, we review the latest research progress on the mechanisms of nitrosative stress-mediated cell death, primarily involving several regulated cell death processes, including apoptosis, autophagy, ferroptosis, pyroptosis, NETosis, and parthanatos, highlighting nitrosative stress as a unique mechanism in cardiovascular diseases.

Antioxidant and anti-inflammatory peptide fraction from oyster soft tissue by enzymatic hydrolysis

Recent studies have confirmed that the peptide fractions derived from marine organisms exhibit good antioxidant and anti-inflammatory activity, and oyster is an excellent nutrient resource with high-protein content. In this study, the peptide fractions from oyster soft tissue were prepared after hydrolysis by pepsin (pH 2, 37°C), trypsin (pH 8, 37°C), and Maxipro PSP (pH 4.2, 50°C) with the optimized parameters (enzyme-to-substrate (E/S) ratio, 1:100 (w/w); hydrolysis time, 4 hr), respectively. Four fractions named as PEP-1, PEP-2, TRYP-2, and MIX-2 were obtained after separation with elution consisting of 20% or 40% ethanol. The MIX-2 exhibited the highest hydrophobicity correlated well with its hydrophobic amino acid content, and TRYP-2 exhibited much better antioxidant activity than other three elution samples. Furthermore, all of the bioactive peptide fractions were noncytotoxic and could selectively repress pro-inflammatory mediators, TNF-α, IL-1β, IL-6, and i-NOS, at transcription level in RAW264.7 macrophage cells after LPS stimulation. The result suggests that the peptide fraction TRYP-2 from oyster soft tissue hydrolysates might be a potential resource for natural anti-inflammatory components.

Cold-inducible RNA-binding protein (CIRBP) promotes porcine reproductive and respiratory syndrome virus (PRRSV)-induced inflammatory response

Porcine reproductive and respiratory syndrome virus (PRRSV) infection causes severe systemic inflammation. Based on transcriptome sequencing data, a new cold-inducible RNA-binding protein (CIRBP) was identified, and its upregulated expression was detected in PRRSV-infected porcine alveolar macrophages (PAMs). However, the immunoregulatoryeffect of CIRBP in PRRSV infection remains unclear. In this study, we found that CIRBP, as an RNA-binging protein, migrates to the cytoplasm from the nucleus and exists in cytoplasmic stress granules under PRRSV infection. In addition, as a new pro-inflammatory factor, the overexpression of CIRBP promotes the expression of inflammatory cytokines and oxidative stress as showing the production of iNOS and ROS in PRRSV-infected cells, which contributes to the inflammatory response via the NF-κB pathway. Our findings suggested that CIRBP is involved in the regulation of PRRSV-induced inflammatory response.

The Apolipoprotein A-I Mimetic L-4F Attenuates Monocyte Activation and Adverse Cardiac Remodeling after Myocardial Infarction

Excessive inflammation after myocardial infarction (MI) can promote infarct expansion and adverse left ventricular (LV) remodeling. L-4F, a mimetic peptide of apolipoprotein A-I (apoA-I), exhibits anti-inflammatory and anti-atherogenic properties; however, whether L-4F imparts beneficial effects after myocardial infarction (MI) is unknown. Here we demonstrate that L-4F suppresses the expansion of blood, splenic, and myocardial pro-inflammatory monocytes and macrophages in a mouse model of reperfused MI. Changes in immune cell profiles were accompanied by alleviation of post-MI LV remodeling and dysfunction. In vitro, L-4F also inhibited pro-inflammatory and glycolytic gene expression in macrophages. In summary, L-4F treatment prevents prolonged and excessive inflammation after MI, in part through modulation of pro-inflammatory monocytes and macrophages, and improves post-MI LV remodeling. These data suggest that L-4F could be a used as a therapeutic adjunct in humans with MI to limit inflammation and alleviate the progression to heart failure.

Exogenous CXCL4 infusion inhibits macrophage phagocytosis by limiting CD36 signalling to enhance post-myocardial infarction cardiac dilation and mortality

Aims

Macrophage phagocytosis of dead cells is a prerequisite for inflammation resolution. Because CXCL4 induces macrophage phagocytosis in vitro, we examined the impact of exogenous CXCL4 infusion on cardiac wound healing and macrophage phagocytosis following myocardial infarction (MI).

Methods and results

CXCL4 expression significantly increased in the infarct region beginning at Day 3 post-MI, and macrophages were the predominant source. Adult male C57BL/6J mice were subjected to coronary artery occlusion, and MI mice were randomly infused with recombinant mouse CXCL4 or saline beginning at 24 h post-MI by mini-pump infusion. Compared with saline controls, CXCL4 infusion dramatically reduced 7 day post-MI survival [10% (3/30) for CXCL4 vs. 47% (7/15) for saline, P < 0.05] as a result of acute congestive heart failure. By echocardiography, CXCL4 significantly increased left ventricular (LV) volumes and dimensions at Day 5 post-MI (all P < 0.05), despite similar infarct areas compared with saline controls. While macrophage numbers were similar at Day 5 post-MI, CXCL4 infusion increased Ccr4 and Itgb4 and decreased Adamts8 gene levels in the infarct region, all of which linked to CXCL4-mediated cardiac dilation. Isolated Day 5 post-MI macrophages exhibited comparable levels of M1 and M4 markers between saline and CXCL4 groups. Interestingly, by both ex vivo and in vitro phagocytosis assays, CXCL4 reduced macrophage phagocytic capacity, which was connected to decreased levels of the phagocytosis receptor CD36. In vitro, a CD36 neutralizing antibody (CD36Ab) significantly inhibited macrophage phagocytic capacity. The combination of CXCL4 and CD36Ab did not have an additive effect, indicating that CXCL4 regulated phagocytosis through CD36 signalling. CXCL4 infusion significantly elevated infarct matrix metalloproteinase (MMP)-9 levels at Day 5 post-MI, and MMP-9 can cleave CD36 as a down-regulation mechanism.

Conclusion

CXCL4 infusion impaired macrophage phagocytic capacity by reducing CD36 levels through MMP-9 dependent and independent signalling, leading to higher mortality and LV dilation.

Protective Effects of Activated Myofibroblasts in the Pressure-Overloaded Myocardium Are Mediated Through Smad-Dependent Activation of a Matrix-Preserving Program

RATIONALE

The heart contains abundant interstitial and perivascular fibroblasts. Traditional views suggest that, under conditions of mechanical stress, cytokines, growth factors, and neurohumoral mediators stimulate fibroblast activation, inducing ECM (extracellular matrix) protein synthesis and promoting fibrosis and diastolic dysfunction. Members of the TGF (transforming growth factor)-β family are upregulated and activated in the remodeling myocardium and modulate phenotype and function of all myocardial cell types through activation of intracellular effector molecules, the Smads (small mothers against decapentaplegic), and through Smad-independent pathways.

OBJECTIVES

To examine the role of fibroblast-specific TGF-β/Smad3 signaling in the remodeling pressure-overloaded myocardium.

METHODS AND RESULTS

We examined the effects of cell-specific Smad3 loss in activated periostin-expressing myofibroblasts using a mouse model of cardiac pressure overload, induced through transverse aortic constriction. Surprisingly, FS3KO (myofibroblast-specific Smad3 knockout) mice exhibited accelerated systolic dysfunction after pressure overload, evidenced by an early 40% reduction in ejection fraction after 7 days of transverse aortic constriction. Accelerated systolic dysfunction in pressure-overloaded FS3KO mice was associated with accentuated matrix degradation and generation of collagen-derived matrikines, accompanied by cardiomyocyte myofibrillar loss and apoptosis, and by enhanced macrophage-driven inflammation. In vitro, TGF-β1, TGF-β2, and TGF-β3 stimulated a Smad3-dependent matrix-preserving phenotype in cardiac fibroblasts, suppressing MMP (matrix metalloproteinase)-3 and MMP-8 synthesis and inducing TIMP (tissue inhibitor of metalloproteinases)-1. In vivo, administration of an MMP-8 inhibitor attenuated early systolic dysfunction in pressure-overloaded FS3KO mice, suggesting that the protective effects of activated cardiac myofibroblasts in the pressure-overloaded myocardium are, at least in part, because of suppression of MMPs and activation of a matrix-preserving program. MMP-8 stimulation induces a proinflammatory phenotype in isolated macrophages.

CONCLUSIONS

In the pressure-overloaded myocardium, TGF-β/Smad3-activated cardiac fibroblasts play an important protective role, preserving the ECM network, suppressing macrophage-driven inflammation, and attenuating cardiomyocyte injury. The protective actions of the myofibroblasts are mediated, at least in part, through Smad-dependent suppression of matrix-degrading proteases.

Small molecule inhibitors and stimulators of inducible nitric oxide synthase in cancer cells from natural origin (phytochemicals, marine compounds, antibiotics)

Nitric oxide synthases (NOS) are a family of isoforms, which generate nitric oxide (NO). NO is one of the smallest molecules in nature and acts mainly as a potent vasodilator. It participates in various biological processes ranging from physiological to pathological conditions. Inducible NOS (iNOS, NOS2) is a calcium-independent and inducible isoform. Despite high iNOS expression in many tumors, the role of iNOS is still unclear and complex with both enhancing and prohibiting actions in tumorigenesis. Nature presents a broad variety of natural stimulators and inhibitors, which may either promote or inhibit iNOS response. In the present review, we give an overview of iNOS-modulating agents with a special focus on both natural and synthetic molecules and their effects in related biological processes. The role of iNOS in physiological and pathological conditions is also discussed.

Crocetin alleviates myocardial ischemia/reperfusion injury by regulating inflammation and the unfolded protein response

Crocetin, a natural compound, has been demonstrated to exhibit beneficial effects in cardiovascular diseases. Previous studies demonstrated that crocetin reduced ischemia/reperfusion (I/R) injury by attenuating cytotoxicity and cellular apoptosis. However, the previous mechanistic studies did not fully elucidate its pharmacological effects on cardiac damage, especially I/R injury. The present study verified its cardioprotective effects in a Langendorff perfusion system, an ex vivo model of I/R. It was demonstrated that crocetin significantly attenuated the activities of pro-inflammatory cytokines and nuclear factor erythroid-2 related factor 2 (Nrf2)/heme oxygenase-1 signaling. The present study provided novel insight that crocetin regulated the unfolded protein response (UPR) and decreased associated protein levels to protect the heart. Furthermore, it was identified that Nrf2 played a key role in the cardioprotective effect of crocetin by attenuating inflammation and the UPR.

Nitric Oxide Synthase 2 Induction Promotes Right Ventricular Fibrosis

The ability of the right ventricle to compensate pressure overload determines survival in pulmonary arterial hypertension (PAH). Nitric oxide (NO) reduces the right ventricular afterload through pulmonary vasodilation, but excessive NO amounts cause oxidative stress. Oxidative stress drives remodeling of pulmonary arteries and the right ventricle. In the present study, we hypothesized that nitric oxide synthase 2 (NOS2) induction leads to excessive NO amounts that contribute to oxidative stress and impair right ventricular adaptation to PAH. We used a surgical pulmonary artery banding (PAB) mouse model in which right ventricular dysfunction and remodeling occur independently of changes in the pulmonary vasculature. Three weeks after PAB, NOS2 expression was increased twofold in the hypertrophied right ventricle on transcript and protein levels together with increased NO production. Histomorphology localized NOS2 in interstitial and perivascular cardiac fibroblasts after PAB, which was confirmed by cell isolation experiments. In the hypertrophied right ventricle, NOS2 induction was accompanied by an increased formation of reactive oxidants blocked by ex vivo NOS inhibition. We show that reactive oxidant formation in the hypertrophied right ventricle is in part NOS2 dependent (in NOS2-deficient mice [NOS2^-/-]). Lack of NOS2 induction prevented superoxide scavenging and decreased reactive oxidant formation. Functional measures of cardiac function by noninvasive echocardiography together with intracardiac catheterization revealed no differences in heart function between both genotypes after PAB. However, reduced NO and reactive oxidant formation in the hypertrophied right ventricle of NOS2^-/- mice was linked to reduced collagen accumulation through reduced collagen deposition from the cardiac fibroblast. Together, our data demonstrate a profibrotic role for NOS2 induction in the hypertrophied right ventricle.

CTRP9 induces iNOS expression through JAK2/STAT3 pathway in Raw 264.7 and peritoneal macrophages

The C1q tumor necrosis factor (TNF)-related proteins 9 (CTRP9), an adipocyte-derived cytokine, affects a number of physiological processes, including immune function and inflammation. We investigated whether CTRP9 affects the expression of inflammation-related genes in Raw 264.7 and peritoneal macrophages. The CTRP9-induced expression of iNOS increased in a time- and dose-dependent manner. LPS and CTRP9 promote the expression of iNOS jointly in Raw 264.7 and peritoneal macrophages. CTRP9 induced the phosphorylation of JAK2 and STAT3 in Raw 264.7 and peritoneal macrophages. VX509 (JAK2 inhibitor) reduced the CTRP9-induced iNOS protein production. In addition, the CTRP9-induced phosphorylation of JAK2 and STAT3 was dramatically reduced by VX509. Collectively, these results suggest that JAK2/STAT3 signaling is involved in the CTRP9-induced expression of iNOS.

Molecular Imaging of Myocardial Inflammation With Positron Emission Tomography Post-Ischemia: A Determinant of Subsequent Remodeling or Recovery

Inflammation after myocardial ischemia influences ventricular remodeling and repair and has emerged as a therapeutic target. Conventional diagnostic measurements address systemic inflammation but cannot quantify local tissue changes. Molecular imaging facilitates noninvasive assessment of leukocyte infiltration into damaged myocardium. Preliminary experience with ¹⁸F-labeled fluorodeoxyglucose ([¹⁸F]FDG) demonstrates localized inflammatory cell signal within the infarct territory as an independent predictor of subsequent ventricular dysfunction. Novel targeted radiotracers may provide additional insight into the enrichment of specific leukocyte populations. Challenges to wider implementation of inflammation imaging after myocardial infarction include accurate and reproducible quantification, prognostic value, and capacity to monitor inflammation response to novel treatment. This review describes myocardial inflammation following ischemia as a molecular imaging target and evaluates established and emerging radiotracers for this application. Furthermore, the potential role of inflammation imaging to provide prognostic information, support novel drug and therapeutic research, and assess biological response to cardiac disease is discussed.

Dysfunctional and Proinflammatory Regulatory T-Lymphocytes Are Essential for Adverse Cardiac Remodeling in Ischemic Cardiomyopathy

BACKGROUND

Heart failure (HF) is a state of inappropriately sustained inflammation, suggesting the loss of normal immunosuppressive mechanisms. Regulatory T-lymphocytes (Tregs) are considered key suppressors of immune responses; however, their role in HF is unknown. We hypothesized that Tregs are dysfunctional in ischemic cardiomyopathy and HF, and they promote immune activation and left ventricular (LV) remodeling.

METHODS

Adult male wild-type C57BL/6 mice, Foxp3-diphtheria toxin receptor transgenic mice, and tumor necrosis factor (TNF) α receptor-1 (TNFR1)^-/- mice underwent nonreperfused myocardial infarction to induce HF or sham operation. LV remodeling was assessed by echocardiography as well as histological and molecular phenotyping. Alterations in Treg profile and function were examined by flow cytometry, immunostaining, and in vitro cell assays.

RESULTS

Compared with wild-type sham mice, CD4⁺Foxp3⁺ Tregs in wild-type HF mice robustly expanded in the heart, circulation, spleen, and lymph nodes in a phasic manner after myocardial infarction, beyond the early phase of wound healing, and exhibited proinflammatory T helper 1-type features with interferon-γ, TNFα, and TNFR1 expression, loss of immunomodulatory capacity, heightened proliferation, and potentiated antiangiogenic and profibrotic properties. Selective Treg ablation in Foxp3-diphtheria toxin receptor mice with ischemic cardiomyopathy reversed LV remodeling and dysfunction, alleviating hypertrophy and fibrosis, while suppressing circulating CD4⁺ T cells and systemic inflammation and enhancing tissue neovascularization. Tregs reconstituted after ablation exhibited restoration of immunosuppressive capacity and normalized TNFR1 expression. Treg dysfunction was also tightly coupled to Treg-endothelial cell contact- and TNFR1-dependent inhibition of angiogenesis and the mobilization and tissue infiltration of CD34⁺Flk1⁺ circulating angiogenic cells in a C-C chemokine ligand 5/C-C chemokine receptor 5-dependent manner. Anti-CD25-mediated Treg depletion in wild-type mice imparted similar benefits on LV remodeling, circulating angiogenic cells, and tissue neovascularization.

CONCLUSIONS

Proinflammatory and antiangiogenic Tregs play an essential pathogenetic role in chronic ischemic HF to promote immune activation and pathological LV remodeling. The restoration of normal Treg function may be a viable approach to therapeutic immunomodulation in this disease.

Protection of the myocardium against ischemia/reperfusion injury by punicalagin through an SIRT1-NRF-2-HO-1-dependent mechanism

Punicalagin has been found to exert cardiac protective effects against myocardial ischemia/reperfusion (MI/R) injury, although the detailed mechanisms remain largely unknown. This experiment was performed to explore the potential involvement of silent information regulator 1 (SIRT1)-NFE2-related factor 2 (NRF-2)-heme oxygenase-1 (HO-1) pathway in the cardiac protective actions of punicalagin. Sprague-Dawley (SD) rats were subjected to MI/R operation with or without punicalagin treatment (40 mg kg^-1d^-1). We showed that punicalagin-treated group exhibited enhanced cardiac function, reduced myocardial infarction and decreased cleaved caspase-3 level. Furthermore, myocardial oxidative/nitrosative stress was ameliorated by punicalagin as evidenced by suppressed superoxide generation, gp91^phox and iNOS expressions, NO metabolites as well as myocardial nitrotyrosine level. Additionally, punicalagin decreased myocardial IL-6, TNF-α and the levels of ICAM-1, VCAM-1 and IKK-β expressions as well as IκB-α phosphorylation and NF-κB nuclear translocation. However, these effects were abolished by EX527 (5 mg kg^-1d^-1, a selective SIRT1 inhibitor). We further found that punicalagin dose-dependently enhanced SIRT1 nuclear distribution and NRF-2-HO-1 signaling. While EX527 treatment not only reduced SIRT1 activity, but also reversed the activation of NRF-2-HO-1 pathway. Collectively, these results revealed that punicalagin reduced cardiac oxidative/nitrosative stress and inflammatory response induced by MI/R operation through SIRT1-mediated activation of NRF-2-HO-1 signaling.

Increased Plasma Soluble Fractalkine in Patients with Chronic Heart Failure and Its Clinical Significance

Fractalkine has been reported to play an important role in the pathophysiology of various cardiovascular disorders. This research aims to study the change of soluble fractalkine (sFKN) in plasma level of patients with chronic heart failure (CHF) and evaluate its prognostic value.A total of 96 patients with CHF and 45 healthy subjects were included in this study. The plasma levels of sFKN, brain natriuretic peptide (BNP), and Interleukin-18 (IL-18) were determined by ELISA kits when they were first admitted to the hospital. Left ventricular ejection fraction (LVEF) was measured by echocardiogram. Rehospitalization status within 1 year after the first hospitalization was also recorded.The plasma levels of sFKN, BNP, and IL-18 in patients with CHF were significantly higher than in the control group (P < 0.05). The concentrations of sFKN and BNP were increased with the severity of heart failure classified by NYHA classification (P < 0.05). There were no statistical differences among all CHF subgroups classified by etiology (P > 0.05). Plasma sFKN level in CHF group was positively correlated with BNP (r = 0.441, P < 0.001) and IL-18 (r = 0.592, P < 0.001). Receiver operating characteristic curve analysis showed that area under the curve values of FKN, BNP, and IL-18 were 0.885 (95%CI: 0.810 to 0.960, P < 0.001), 0.889 (95%CI: 0.842 to 0.956, P < 0.001), and 0.878 (95%CI: 0.801-0.954, P < 0.001), respectively. The concentrations of sFKN and BNP were increased in patients readmitted more than once within 1 year (P < 0.05).

Clofibrate Treatment Decreases Inflammation and Reverses Myocardial Infarction-Induced Remodelation in a Rodent Experimental Model

Myocardial infarction (MI) initiates an inflammatory response that promotes both beneficial and deleterious effects. The early response helps the myocardium to remove damaged tissue; however, a prolonged later response brings cardiac remodeling characterized by functional, metabolic, and structural pathological changes. Current pharmacological treatments have failed to reverse ischemic-induced cardiac damage. Therefore, our aim was to study if clofibrate treatment was capable of decreasing inflammation and apoptosis, and reverse ventricular remodeling and MI-induced functional damage. Male Wistar rats were assigned to (1) Sham coronary artery ligation (Sham) or (2) Coronary artery ligation (MI). Seven days post-MI, animals were further divided to receive vehicle (V) or clofibrate (100 mg/kg, C) for 7 days. The expression of IL-6, TNF-α, and inflammatory related molecules ICAM-1, VCAM-1, MMP-2 and -9, nuclear NF-kB, and iNOS, were elevated in MI-V. These inflammatory biomarkers decreased in MI-C. Also, apoptotic proteins (Bax and pBad) were elevated in MI-V, while clofibrate augmented anti-apoptotic proteins (Bcl-2 and 14-3-3ε). Clofibrate also protected MI-induced changes in ultra-structure. The ex vivo evaluation of myocardial functioning showed that left ventricular pressure and mechanical work decreased in infarcted rats; clofibrate treatment raised those parameters to control values. Echocardiogram showed that clofibrate partially reduced LV dilation. In conclusion, clofibrate decreases cardiac remodeling, decreases inflammatory molecules, and partly preserves myocardial diameters.

Mst1 promotes cardiac ischemia-reperfusion injury by inhibiting the ERK-CREB pathway and repressing FUNDC1-mediated mitophagy

Cardiac ischemia-reperfusion (I/R) injury results mainly from mitochondrial dysfunction and cardiomyocyte death. Mitophagy sustains mitochondrial function and exerts a pro-survival effect on the reperfused heart tissue. Mammalian STE20-like kinase 1 (Mst1) regulates chronic cardiac metabolic damage and autophagic activity, but its role in acute cardiac I/R injury, especially its effect on mitophagy, is unknown. The aim of this study is to explore whether Mst1 is involved in reperfusion-mediated cardiomyocyte death via modulation of FUN14 domain containing 1 (FUNDC1)-related mitophagy. Our data indicated that Mst1 was markedly increased in reperfused hearts. However, genetic ablation of Mst1 in Mst1-knockout (Mst1-KO) mice significantly reduced the expansion of the cardiac infarction area, maintained myocardial function and abolished I/R-mediated cardiomyocyte death. At the molecular level, upregulation of Mst1 promoted ROS production, reduced mitochondrial membrane potential, facilitated the leakage of mitochondrial pro-apoptotic factors into the nucleus, and activated the caspase-9-related apoptotic pathway in reperfused cardiomyocytes. Mechanistically, Mst1 activation repressed FUNDC1 expression and consequently inhibited mitophagy. However, deletion of Mst1 was able to reverse FUNDC1 expression and thus re-activate protective mitophagy, effectively sustaining mitochondrial homeostasis and blocking mitochondrial apoptosis in reperfused cardiomyocytes. Finally, we demonstrated that Mst1 regulated FUNDC1 expression via the MAPK/ERK-CREB pathway. Inhibition of the MAPK/ERK-CREB pathway prevented FUNDC1 activation caused by Mst1 deletion. Altogether, our data confirm that Mst1 deficiency sends a pro-survival signal for the reperfused heart by reversing FUNDC1-related mitophagy and thus reducing cardiomyocyte mitochondrial apoptosis, which identifies Mst1 as a novel regulator for cardiac reperfusion injury via modulation of mitochondrial homeostasis.

Inflammatory cells and their non-coding RNAs as targets for treating myocardial infarction

Myocardial infarction triggers infiltration of several types of immune cells that coordinate both innate and adaptive immune responses. These play a dual role in post-infarction cardiac remodeling by initiating and resolving inflammatory processes, which needs to occur in a timely and well-orchestrated way to ensure a reestablishment of normalized cardiac functions. Thus, therapeutic modulation of immune responses might have benefits for infarct patients. While such strategies have shown great potential in treating cancer, applications in the post-infarction context have been disappointing. One challenge has been the complexity and plasticity of immune cells and their functions in cardiac regulation and healing. The types appear in patterns that are temporally and spatially distinct, while influencing each other and the surrounding tissue. A comprehensive understanding of the immune cell repertoire and their regulatory functions following infarction is sorely needed. Processes of cardiac remodeling trigger additional genetic changes that may also play critical roles in the aftermath of cardiovascular disease. Some of these changes involve non-coding RNAs that play crucial roles in the regulation of immune cells and may, therefore, be of therapeutic interest. This review summarizes what is currently known about the functions of immune cells and non-coding RNAs during post-infarction wound healing. We address some of the challenges that remain and describe novel therapeutic approaches under development that are based on regulating immune responses through non-coding RNAs in the aftermath of the disease.

Overexpression of Mst1 reduces gastric cancer cell viability by repressing the AMPK-Sirt3 pathway and activating mitochondrial fission

BACKGROUND AND OBJECTIVE

Mammalian sterile 20-like kinase 1 (Mst1) plays a critical role in regulating cell survival and apoptosis. However, its influence on gastric cancer cell viability is not understood. Our study aims to explore the specific role of Mst1 in gastric cancer.

MATERIALS AND METHODS

Cellular viability was measured via TUNEL staining, MTT assays, and Western blotting. Immunofluorescence was performed to observe mitochondrial fission. Mst1 overexpression assays were conducted to observe the regulatory mechanisms of Mst1 in mitochondrial fission and cell apoptosis.

RESULTS

The results demonstrated that Mst1 was downregulated in AGS cells when compared with GES-1 cells. However, overexpression of Mst1 reduced cell viability and increased apoptosis in AGS cells. Molecular experiments showed that Mst1 overexpression mediated mitochondrial damage, as evidenced by decreased ATP production, increased ROS generation, more cyt-c translocation from the mitochondria into the cytoplasm and nucleus, and activated the caspase-9-related apoptotic pathway. Furthermore, we found that mitochondrial fission was required for Mst1-induced mitochondrial dysfunction; inhibition of mitochondrial fission sustained mitochondrial homeostasis in response to Mst1 overexpression. In addition, our data revealed that Mst1 controlled mitochondrial fission via repressing the AMPK-Sirt3 pathway. Activation of the AMPK-Sirt3 pathway negated the promoting effect of Mst1 overexpression on mitochondrial fission.

CONCLUSION

Altogether, our data identified Mst1 as a novel tumor-suppressive factor in promoting cell death in gastric cancer cells by triggering mitochondrial fission and blocking the AMPK-Sirt3 axis.

Excessive mitochondrial fragmentation triggered by erlotinib promotes pancreatic cancer PANC-1 cell apoptosis via activating the mROS-HtrA2/Omi pathways

Background

Mitochondrial fragmentation drastically regulates the viability of pancreatic cancer through a poorly understood mechanism. The present study used erlotinib to activate mitochondrial fragmentation and then investigated the downstream events that occurred in response to mitochondrial fragmentation.

Methods

Cell viability and apoptosis were determined via MTT assay, TUNEL staining and ELISA. Mitochondrial fragmentation was measured via an immunofluorescence assay and qPCR. siRNA transfection and pathway blockers were used to perform the loss-of-function assays.

Results

The results of our study demonstrated that erlotinib treatment mediated cell apoptosis in the PANC-1 pancreatic cancer cell line via evoking mitochondrial fragmentation. Mechanistically, erlotinib application increased mitochondrial fission and reduced mitochondrial fusion, triggering mitochondrial fragmentation. Subsequently, mitochondrial fragmentation caused the overproduction of mitochondrial ROS (mROS). Interestingly, excessive mROS induced cardiolipin oxidation and mPTP opening, finally facilitating HtrA2/Omi liberation from the mitochondria into the cytoplasm, where HtrA2/Omi activated caspase-9-dependent cell apoptosis. Notably, neutralization of mROS or knockdown of HtrA2/Omi attenuated erlotinib-mediated mitochondrial fragmentation and favored cancer cell survival.

Conclusions

Together, our results identified the mROS-HtrA2/Omi axis as a novel signaling pathway that is activated by mitochondrial fragmentation and that promotes PANC-1 pancreatic cancer cell mitochondrial apoptosis in the presence of erlotinib.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0665-1) contains supplementary material, which is available to authorized users.

Mst1 deletion attenuates renal ischaemia-reperfusion injury: The role of microtubule cytoskeleton dynamics, mitochondrial fission and the GSK3β-p53 signalling pathway

Despite extensive research that has been carried out over the past three decades in the field of renal ischaemia-reperfusion (I/R) injury, the pathogenic role of mitochondrial fission in renal I/R injury is poorly understood. The aim of our study is to investigate the molecular mechanism by which mammalian STE20-like kinase 1 (Mst1) participates in renal I/R injury through modifying mitochondrial fission, microtubule cytoskeleton dynamics, and the GSK3β-p53 signalling pathway. Our data demonstrated that genetic ablation of Mst1 improved renal function, alleviated reperfusion-mediated tubular epithelial cell apoptosis, and attenuated the vulnerability of kidney to I/R injury. At the molecular level, Mst1 upregulation exacerbated mitochondrial damage, as evidenced by reduced mitochondrial potential, increased ROS generation, more cyt-c liberation from mitochondria into the cytoplasm, and an activated mitochondrial apoptotic pathway. Furthermore, we demonstrated that I/R-mediated mitochondrial damage resulted from mitochondrial fission, and the blockade of mitochondrial fission preserved mitochondrial homeostasis in the I/R setting. Functional studies have discovered that Mst1 regulated mitochondrial fission through two mechanisms: induction of Drp1 phosphorylation and enhancement of F-actin assembly. Activated Mst1 promoted Drp1 phosphorylation at Ser616, contributing to Drp1 translocation from the cytoplasm to the surface of the mitochondria. Additionally, Mst1 facilitated F-actin polymerization, contributing to mitochondrial contraction. Finally, we confirmed that Mst1 regulated Drp1 post-transcriptional modification and F-actin stabilization via the GSK3β-p53 signalling pathway. Inhibition of GSK3β-p53 signalling provided a survival advantage for the tubular epithelial cell in the context of renal I/R injury by repressing mitochondrial fission. Collectively, our study identified Mst1 as the primary pathogenesis for the development and progression of renal I/R injury via activation of fatal mitochondrial fission by modulating Drp1 phosphorylation, microtubule cytoskeleton dynamics, and the GSK3β-p53 signalling pathway.

•

Mst1 deletion sustains renal function after I/R injury.

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Excessive mitochondrial fission accounts for Mst1-mediated mitochondrial apoptosis.

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Mst1 enhances reperfusion-mediated mitochondrial fission via Drp1 phosphorylation and F-actin polymerization.

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Mst1 regulates Drp1 phosphorylation and F-actin polymerization by activating the GSK3β-p53 axis.

Sirtuin‑1 protects hair follicle stem cells from TNFα-mediated inflammatory stress via activating the MAPK-ERK-Mfn2 pathway

OBJECTIVE

Stem cell transplantation is a promising tool to treat burn injuries. However, the inflammatory microenvironment in damaged skin limits the efficiency of stem cell-based therapy via poorly understood mechanisms. The aim of our study is to explore the contribution and mechanism of Sirtuin-1 (Sirt1) in TNFα-mediated inflammatory stress in hair follicle stem cells (HFSCs).

METHODS

Cellular viability was determined using the MTT assay, TUNEL staining, western blot analysis and LDH release assay. Adenovirus-loaded Sirt1 was transduced into HFSCs to overexpress Sirt1 in the presence of TNFα. Mitochondrial function was determined using JC-1 staining, mitochondrial ROS staining, immunofluorescence staining and western blotting.

RESULTS

Sirt1 was downregulated in response to the TNFα treatment. Additionally, TNFα stress reduced the viability, mobility and proliferation of HFSCs, and these effects were reversed by the overexpression of Sirt1. At the molecular level, Sirt1 overexpression attenuated TNFα-mediated mitochondrial damage, as evidenced by increased mitochondrial energy metabolism, decreased mitochondrial ROS generation, stabilized mitochondrial potential and blockage of the mitochondrial apoptotic pathway. Furthermore, Sirt1 modulated mitochondrial homeostasis by activating the MAPK-ERK-Mfn2 axis; inhibition of this pathway abrogated the protective effects of Sirt1 on HFSC survival, migration and proliferation.

SIGNIFICANCE

Based on our results, the inflammatory stress-mediated HFSC injury may be associated with a decrease in Sirt1 expression and subsequent mitochondrial dysfunction. Accordingly, strategies designed to enhance Sirt1 expression would be an effective approach to enhance the survival of HFSCs in the inflammatory microenvironment.

BI1 alleviates cardiac microvascular ischemia-reperfusion injury via modifying mitochondrial fission and inhibiting XO/ROS/F-actin pathways

Pathogenesis of cardiac microvascular ischemia-reperfusion (IR) injury is associated with excessive mitochondrial fission. However, the upstream mediator of mitochondrial fission remains obscure. Bax inhibitor 1 (BI1) is linked to multiple mitochondrial functions, and there have been no studies investigating the contribution of BI1 on mitochondrial fission in the setting of cardiac microvascular IR injury. This study was undertaken to establish the action of BI1 on the cardiac microvascular reperfusion injury and figure out whether BI1 sustained endothelial viability via inhibiting mitochondrial fission. Our observation indicated that BI1 was downregulated in reperfused hearts and overexpression of BI1 attenuated microvascular IR injury. Mechanistically, reperfusion injury elevated the levels of xanthine oxidase (XO), an effect that was followed by increased reactive oxygen species (ROS) production. Subsequently, oxidative stress mediated F-actin depolymerization and the latter promoted mitochondrial fission. Aberrant fission caused mitochondrial dysfunction and ultimately activated mitochondrial apoptosis in cardiac microvascular endothelial cells. By comparison, BI1 overexpression repressed XO expression and thus neutralized ROS, interrupting F-actin-mediated mitochondrial fission. The inhibitory effect of BI1 on mitochondrial fission sustained endothelial viability, reversed endothelial barrier integrity, attenuated the microvascular inflammation response, and maintained microcirculation patency. Altogether, we conclude that BI1 is essential in maintaining mitochondrial homeostasis and alleviating cardiac microvascular IR injury. Deregulated BI1 via the XO/ROS/F-actin pathways plays a causative role in the development of cardiac microvascular reperfusion injury.

Therapeutic effect of Sirtuin 3 on ameliorating nonalcoholic fatty liver disease: The role of the ERK-CREB pathway and Bnip3-mediated mitophagy

Increased mitochondrial damage is related to the progression of a diet-induced nonalcoholic fatty liver disease. The aim of our study is to investigate the role of Sirtuin 3 (Sirt3) in treating nonalcoholic fatty liver disease with a focus on mitophagy and the ERK-CREB pathway. Our data indicated that Sirt3 was downregulated in liver tissue in response to chronic HFD treatment. Interestingly, re-introduction of Sirt3 protected hepatic function, attenuated liver fibrosis, alleviated the inflammatory response, and prevented hepatocyte apoptosis. Molecular investigations demonstrated that lipotoxicity was associated with an increase in mitochondrial apoptosis as evidenced by reduced mitochondrial potential, augmented ROS production, increased cyt-c leakage into the nucleus, and activated caspase-9 apoptotic signalling. Additionally, Sirt3 overexpression protected hepatocytes against mitochondrial apoptosis via promoting Bnip3-required mitophagy. Functional studies showed that Sirt3 reversed Bnip3 expression and mitophagy activity via the ERK-CREB signalling pathway. Blockade of the ERK-CREB axis repressed the promotive effects of Sirt3 on Bnip3 activation and mitophagy augmentation, finally negating the anti-apoptotic influences of Sirt3 on hepatocytes in the setting of high-fat-stress. Collectively, our data show that high-fat-mediated liver damage is associated with Sirt3 downregulation, which is followed by ERK-CREB pathway inactivation and Bnip3-mediated inhibition of mitophagy, causing hepatocytes to undergo mitochondria-dependent cell death. Based on this, strategies for enhancing Sirt3 activity and activating the ERK-CREB-Bnip3-mitophagy pathways could be used to treat nonalcoholic fatty liver disease.

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Sirt3 overexpression prevents diet-mediated fatty liver disease.

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Sirt3 blocks hepatocyte mitochondrial apoptosis in the setting of high-fat injury.

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Bnip3-mediated mitophagy protects mitochondria against high-fat-mediated damage.

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Sirt3 controls Bnip3-mediated mitophagy via the ERK-CREB signalling pathway.

Effects of neuromuscular electrical stimulation in patients with heart failure - review

Research conducted in the last two decades suggests that neuromuscular electrical stimulation of the lower limb muscles (NMES) may be a "bridge" to conventional exercise or an alternative for patients with advanced chronic heart failure (CHF), non-compliant or non-responsive to physical training. Through stimulating the work of the skeletal muscles, NMES increases the functional capacity, muscle mass and endurance in patients with CHF. A beneficial effect of NMES on functional capacity, vascular endothelial function, quality of life and aerobic enzymes activity has been shown. A significant benefit of this novel therapy in heart failure is the fact that the procedure can be home-based, after prior guidance of the patient.