Tumor necrosis factor in the heart

The role of pyroptosis in heart failure and related traditional chinese medicine treatments

Pyroptosis is a type of programmed cell death that is mediated by both typical and atypical pathways and ultimately leads to the lysis and rupture of cell membranes and the release of proinflammatory factors, triggering an intense inflammatory response. Heart failure (HF) is a serious and terminal stage of various heart diseases. Myocardial hypertrophy, myocardial fibrosis, ventricular remodeling, oxidative stress, the inflammatory response and cardiomyocyte ionic disorders caused by various cardiac diseases are all risk factors for and aggravate HF. Numerous studies have shown that pyroptosis can induce and exacerbate these reactions, causing progression to HF. Therefore, targeting pyroptosis is a promising strategy to treat HF. This paper summarizes the role of pyroptosis in the development of HF and the underlying mechanism involved. Recent research progress on the ability of traditional Chinese medicine (TCM) extracts and formulas to inhibit pyroptosis and treat HF was summarized, and some traditional Chinese medicine extracts and formulas can alleviate different types of HF, including heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), and heart failure with midrange ejection fraction (HFmrEF), by targeting pyroptosis. These findings may provide new ideas and evidence for the treatment or adjuvant treatment of HF by targeting pyroptosis.

The Exacerbating Effects of the Tumor Necrosis Factor in Cardiovascular Stenosis: Intimal Hyperplasia

TNF-α functions as a master regulator of inflammation, and it plays a prominent role in several immunological diseases. By promoting important cellular mechanisms, such as cell proliferation, migration, and phenotype switch, TNF-α induces its exacerbating effects, which are the underlying cause of many proliferative diseases such as cancer and cardiovascular disease. TNF-α primarily alters the immune component of the disease, which subsequently affects normal functioning of the cells. Monoclonal antibodies and synthetic drugs that can target TNF-α and impair its effects have been developed and are currently used in the treatment of a few select human diseases. Vascular restenosis is a proliferative disorder that is initiated by immunological mechanisms. In this review, the role of TNF-α in exacerbating restenosis resulting from neointimal hyperplasia, as well as molecular mechanisms and cellular processes affected or induced by TNF-α, are discussed. As TNF-α-targeting drugs are currently not approved for the treatment of restenosis, the summation of the topics discussed here is anticipated to provide information that can emphasize on the use of TNF-α-targeting drug candidates to prevent vascular restenosis.

Food-grade titanium dioxide and zinc oxide nanoparticles induce toxicity and cardiac damage after oral exposure in rats

BACKGROUND

Metallic nanoparticles (NPs) are widely used as food additives for human consumption. NPs reach the bloodstream given their small size, getting in contact with all body organs and cells. NPs have adverse effects on the respiratory and intestinal tract; however, few studies have focused on the toxic consequences of orally ingested metallic NPs on the cardiovascular system. Here, the effects of two food-grade additives on the cardiovascular system were analyzed.

METHODS

Titanium dioxide labeled as E171 and zinc oxide (ZnO) NPs were orally administered to Wistar rats using an esophageal cannula at 10 mg/kg bw every other day for 90 days. We evaluated cardiac cell morphology and death, expression of apoptotic and autophagic proteins in cardiac mitochondria, mitochondrial dysfunction, and concentration of metals on cardiac tissue.

RESULTS

Heart histology showed important morphological changes such as presence of cellular infiltrates, collagen deposition and mitochondrial alterations in hearts from rats exposed to E171 and ZnO NPs. Intracellular Cyt-C levels dropped, while TUNEL positive cells increased. No significant changes in the expression of inflammatory cytokines were detected. Both NPs altered mitochondrial function indicating cardiac dysfunction, which was associated with an elevated concentration of calcium. ZnO NPs induced expression of caspases 3 and 9 and two autophagic proteins, LC3B and beclin-1, and had the strongest effect compared to E171.

CONCLUSIONS

E171 and ZnO NPs induce adverse cardiovascular effects in rats after 90 days of exposure, thus food intake containing these additives, should be taken into consideration, since they translocate into the bloodstream and cause cardiovascular damage.

Sex as Biological Variable in Cardiac Mitochondrial Bioenergetic Responses to Acute Stress

Cardiac dysfunction/damage following trauma, shock, sepsis, and ischemia impacts clinical outcomes. Acute inflammation and oxidative stress triggered by these injuries impair mitochondria, which are critical to maintaining cardiac function. Despite sex dimorphisms in consequences of these injuries, it is unclear whether mitochondrial bioenergetic responses to inflammation/oxidative stress are sex-dependent. We hypothesized that sex disparity in mitochondrial bioenergetics following TNFα or H2O2 exposure is responsible for reported sex differences in cardiac damage/dysfunction. Methods and Results: Cardiomyocytes isolated from age-matched adult male and female mice were subjected to 1 h TNFα or H2O2 challenge, followed by detection of mitochondrial respiration capacity using the Seahorse XF96 Cell Mito Stress Test. Mitochondrial membrane potential (ΔΨm) was analyzed using JC-1 in TNFα-challenged cardiomyocytes. We found that cardiomyocytes isolated from female mice displayed a better mitochondrial bioenergetic response to TNFα or H2O2 than those isolated from male mice did. TNFα decreased ΔΨm in cardiomyocytes isolated from males but not from females. 17β-estradiol (E2) treatment improved mitochondrial metabolic function in cardiomyocytes from male mice subjected to TNFα or H2O2 treatment. Conclusions: Cardiomyocyte mitochondria from female mice were more resistant to acute stress than those from males. The female sex hormone E2 treatment protected cardiac mitochondria against acute inflammatory and oxidative stress.

Research Progress on the Mechanism of Sepsis Induced Myocardial Injury

Sepsis is an abnormal condition with multiple organ dysfunctions caused by the uncontrolled infection response and one of the major diseases that seriously hang over global human health. Besides, sepsis is characterized by high morbidity and mortality, especially in intensive care unit (ICU). Among the numerous subsequent organ injuries of sepsis, myocardial injury is one of the most common complications and the main cause of death in septic patients. To better manage septic inpatients, it is necessary to understand the specific mechanisms of sepsis induced myocardial injury (SIMI). Therefore, this review will elucidate the pathophysiology of SIMI from the following certain mechanisms: apoptosis, mitochondrial damage, autophagy, excessive inflammatory response, oxidative stress and pyroptosis, and outline current therapeutic strategies and potential approaches in SIMI.

TNF-α Inhibitors and Other Biologic Agents for the Treatment of Immune Checkpoint Inhibitor-Induced Myocarditis

With anti-PD-1 antibodies serving as a representative drug, immune checkpoint inhibitors (ICIs) have become the main drugs used to treat many advanced malignant tumors. However, immune-related adverse events (irAEs), which might involve multiple organ disorders, should not be ignored. ICI-induced myocarditis is an uncommon but life-threatening irAE. Glucocorticoids are the first choice of treatment for patients with ICI-induced myocarditis, but high proportions of steroid-refractory and steroid-resistant cases persist. According to present guidelines, tumor necrosis factor alpha (TNF-α) inhibitors are recommended for patients who fail to respond to steroid therapy and suffer from severe cardiac toxicity, although evidence-based studies are lacking. On the other hand, TNF-α inhibitors are contraindicated in patients with moderate-to-severe heart failure. This review summarizes real-world data from TNF-α inhibitors and other biologic agents for ICI-induced myocarditis to provide more evidence of the efficacy and safety of TNF-α inhibitors and other biologic agents.

Early Protective Role of Inflammation in Cardiac Remodeling and Heart Failure: Focus on TNFα and Resident Macrophages

Cardiac hypertrophy, initiated by a variety of physiological or pathological stimuli (hemodynamic or hormonal stimulation or infarction), is a critical early adaptive compensatory response of the heart. The structural basis of the progression from compensated hypertrophy to pathological hypertrophy and heart failure is still largely unknown. In most cases, early activation of an inflammatory program reflects a reparative or protective response to other primary injurious processes. Later on, regardless of the underlying etiology, heart failure is always associated with both local and systemic activation of inflammatory signaling cascades. Cardiac macrophages are nodal regulators of inflammation. Resident macrophages mostly attenuate cardiac injury by secreting cytoprotective factors (cytokines, chemokines, and growth factors), scavenging damaged cells or mitochondrial debris, and regulating cardiac conduction, angiogenesis, lymphangiogenesis, and fibrosis. In contrast, excessive recruitment of monocyte-derived inflammatory macrophages largely contributes to the transition to heart failure. The current review examines the ambivalent role of inflammation (mainly TNFα-related) and cardiac macrophages (Mφ) in pathophysiologies from non-infarction origin, focusing on the protective signaling processes. Our objective is to illustrate how harnessing this knowledge could pave the way for innovative therapeutics in patients with heart failure.

Modification of Ischemia/Reperfusion-Induced Alterations in Subcellular Organelles by Ischemic Preconditioning

It is now well established that ischemia/reperfusion (I/R) injury is associated with the compromised recovery of cardiac contractile function. Such an adverse effect of I/R injury in the heart is attributed to the development of oxidative stress and intracellular Ca²⁺-overload, which are known to induce remodeling of subcellular organelles such as sarcolemma, sarcoplasmic reticulum, mitochondria and myofibrils. However, repeated episodes of brief periods of ischemia followed by reperfusion or ischemic preconditioning (IP) have been shown to improve cardiac function and exert cardioprotective actions against the adverse effects of prolonged I/R injury. This protective action of IP in attenuating myocardial damage and subcellular remodeling is likely to be due to marked reductions in the occurrence of oxidative stress and intracellular Ca²⁺-overload in cardiomyocytes. In addition, the beneficial actions of IP have been attributed to the depression of proteolytic activities and inflammatory levels of cytokines as well as the activation of the nuclear factor erythroid factor 2-mediated signal transduction pathway. Accordingly, this review is intended to describe some of the changes in subcellular organelles, which are induced in cardiomyocytes by I/R for the occurrence of oxidative stress and intracellular Ca²⁺-overload and highlight some of the mechanisms for explaining the cardioprotective effects of IP.

Effect of Anti-Rheumatic Drugs on Cardiovascular Disease Events in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by erosive arthritis, which can involve multiple systems. Patients with RA may have a variety of comorbidities, including cardiovascular disease (CVD), lung cancer, lymphoma, infection, osteoporosis, fatigue, depression, colon cancer, breast cancer, prostate cancer, and Alzheimer's disease. Among these comorbidities, the incidence of CVD, lung cancer, lymphoma, infection, and osteoporosis is higher. CVD is a serious complication of RA. The risk of CVD and associated mortality rate in patients with RA is high, and the treatment rate is low. In addition to traditional risk factors, such as age, sex, blood pressure, and diabetes, RA is also associated with inflammation. Furthermore, therapeutic drugs for RA, including non-steroidal anti-inflammatory drugs, glucocorticoids, and disease-modifying anti-rheumatic drugs, have beneficial or harmful effects on cardiovascular events in patients with RA. This article discusses the effects of therapeutic drugs for RA on cardiovascular events.

Right ventricular failure: a comorbidity or a clinical emergency?

There has been ample data providing a convincing perception about the underlying mechanism pertaining to left ventricle (LV) hypertrophy progressing towards LV failure. In comparison, data available on the feedback of right ventricle (RV) due to volume or pressure overload is minimal. Advanced imaging techniques have aided the study of physiology, anatomy, and diseased state of RV. However, the treatment scenario of right ventricular failure (RVF) demands more attention. It is a critical clinical risk in patients with carcinoid syndrome, pulmonary hypertension, atrial septal defect, and several other concomitant diseases. Although the remodeling responses of both ventricles on an increase of end-diastolic pressure are mostly identical, the stressed RV becomes more prone to oxidative stress activating the apoptotic mechanism with diminished angiogenesis. This instigates the advancement of RV towards failure in contrast to LV. Empirical heart failure (HF) therapies have been ineffective in improving the mortality rate and cardiac function in patients, which prompted a difference between the underlying pathophysiology of RVF and LV failure. Treatment strategies should be devised, taking into consideration the anatomical and physiological characteristics of RV. This review would emphasize on the pathophysiology of the RVF and the differences between two ventricles in molecular response to stress. A proper insight into the underlying pathophysiology is required to develop optimized therapeutic management in RV-specific HF.

Role of Inflammation and Redox Status on Doxorubicin-Induced Cardiotoxicity in Infant and Adult CD-1 Male Mice

Doxorubicin (DOX) is a topoisomerase II inhibitor commonly used in the treatment of several types of cancer. Despite its efficacy, DOX can potentially cause fatal adverse effects, like cardiotoxicity. This work aimed to assess the role of inflammation in DOX-treated infant and adult mice and its possible link to underlying cardiotoxicity. Two groups of CD-1 male mice of different ages (infants or adults) were subjected to biweekly DOX administrations, to reach a cumulative dose of 18.0 mg/kg, which corresponds approximately in humans to 100.6 mg/m2 for infants and 108.9 mg/m2 for adults a clinically relevant dose in humans. The classic plasmatic markers of cardiotoxicity increased, and that damage was confirmed by histopathological findings in both groups, although it was higher in adults. Moreover, in DOX-treated adults, an increase of cardiac fibrosis was observed, which was accompanied by an increase in specific inflammatory parameters, namely, macrophage M1 and nuclear factor kappa B (NF-κB) p65 subunit, with a trend toward increased levels of the tumor necrosis factor receptor 2 (TNFR2). On the other hand, the levels of myeloperoxidase (MPO) and interleukin (IL)-6 significantly decreased in DOX-treated adult animals. In infants, a significant increase in cardiac protein carbonylation and in the levels of nuclear factor erythroid-2 related factor 2 (Nrf2) was observed. In both groups, no differences were found in the levels of tumor necrosis factor (TNF-α), IL-1β, p38 mitogen-activated protein kinase (p38 MAPK) or NF-κB p52 subunit. In conclusion, using a clinically relevant dose of DOX, our study demonstrated that cardiac effects are associated not only with the intensity of the inflammatory response but also with redox response. Adult mice seemed to be more prone to DOX-induced cardiotoxicity by mechanisms related to inflammation, while infant mice seem to be protected from the damage caused by DOX, possibly by activating such antioxidant defenses as Nrf2.

Minimizing Ischemia Reperfusion Injury in Xenotransplantation

The recent dramatic advances in preventing "initial xenograft dysfunction" in pig-to-non-human primate heart transplantation achieved by minimizing ischemia suggests that ischemia reperfusion injury (IRI) plays an important role in cardiac xenotransplantation. Here we review the molecular, cellular, and immune mechanisms that characterize IRI and associated "primary graft dysfunction" in allotransplantation and consider how they correspond with "xeno-associated" injury mechanisms. Based on this analysis, we describe potential genetic modifications as well as novel technical strategies that may minimize IRI for heart and other organ xenografts and which could facilitate safe and effective clinical xenotransplantation.

Role of IL-37- and IL-37-Treated Dendritic Cells in Acute Coronary Syndrome

As a chronic inflammatory disease, atherosclerosis is a leading cause of morbidity and mortality in most countries. Inflammation is responsible for plaque instability and the subsequent onset of acute coronary syndrome (ACS), which is one of the leading causes of hospitalization. Therefore, exploring the potential mechanism underlying ACS is of considerable concern, and searching for alternative therapeutic targets is very urgent. Interleukin-37 (IL-37) inhibits the production of proinflammatory chemokines and cytokines and acts as a natural inhibitor of innate and adaptive immunity. Interestingly, our previous study with murine models showed that IL-37 alleviated cardiac remodeling and myocardial ischemia/reperfusion injury. Of note, our clinical study revealed that IL-37 is elevated and plays a beneficial role in patients with ACS. Moreover, dendritic cells (DCs) orchestrate both immunity and tolerance, and tolerogenic DCs (tDCs) are characterized by more secretion of immunosuppressive cytokines. As expected, IL-37-treated DCs are tolerogenic. Hence, we speculate that IL-37- or IL-37-treated DCs is a novel therapeutic possibility for ACS, and the precise mechanism of IL-37 requires further study.

Circulating TNFrII levels predict incidence of ischemic heart disease and total mortality, independently of intima media thickness and pulse wave velocity in male with type 2 diabetes

New and clinically useful markers of cardiovascular risk are of great importance in patients with type 2 diabetes since cardiovascular disease is a major cause of death in these patients. We analyzed inflammatory markers and other risk factors for heart disease in 761 patients who participated in the CARDIPP-study, Cardiovascular Risk factors in Patients with Diabetes-a Prospective study in Primary care. All participants had type 2 diabetes and were 55-66 years old at recruitment during the years 2005-2008. Patients were followed for incidence of stroke, myocardial infarction, or death from cardiovascular disease until the end of the year 2018 using the national Swedish Cause of Death and Hospitalization Registries. Besides traditional risk-markers for vascular disease, we also measured carotid-femoral pulse-wave velocity and intima-media thickness of carotid arteries. During a median period of 13 years, 165 men and 65 women died or were hospitalized for ischemic heart disease and stroke. TNFrII showed statistically significance as a risk factor for stroke, ischemic heart disease, and total mortality in male patients with diabetes type 2, independently of age, diabetes duration, BMI, Hba1c, systolic blood pressure, triglycerides, IMT and PWV (p = 0.002, HR 2.70, CI 1.42:5.13, p = 0.002). Circulating TNFrII levels failed to present a similar correlation in women (p = 0.48, CI 0.48:4.84). TNFrII stayed significant in males when HDL/LDL-ratio, CRP and smoking were added to the statistical analysis. Our data support the use of serum TNFrII in male type 2 diabetes patients to add independent prognostic information in terms of mortality and heart disease independently of other strong and well-established risk markers including cholesterol, inflammatory cytokines, PWV and IMT.Trial registration: ClinicalTrials.gov NCT01049737.

Etanercept Ameliorates Cardiac Fibrosis in Rats with Diet-Induced Obesity

Diet-induced obesity (DIO) is considered the main risk factor for cardiovascular diseases. Increases in the plasma levels of tumor necrosis factor alpha (TNF-α) is associated with DIO. Etanercept, a TNF-α inhibitor, has been shown to alleviate cardiac hypertrophy. To investigate the effect of etanercept on cardiac fibrosis in DIO model, rats on high fat diet (HFD) were subdivided into two groups: the etanercept group and vehicle group. Cardiac injury was identified by classic methods, while fibrosis was characterized by histological analysis of the hearts. Etanercept treatment at 0.8 mg/kg/week twice weekly by subcutaneous injection effectively alleviates the cardiac fibrosis in HFD-fed rats. STAT3 activation seems to be induced in parallel with fibrosis-related gene expression in the hearts of HFD-fed rats. Decreased STAT3 activation plays a role in the etanercept-treated animals. Moreover, fibrosis-related genes are activated by palmitate in parallel with STAT3 activation in H9c2 cells. Etanercept may inhibit the effects of palmitate, but it is less effective than a direct inhibitor of STAT3. Direct inhibition of STAT3 activation by etanercept seems unlikely. Etanercept has the ability to ameliorate cardiac fibrosis through reduction of STAT3 activation after the inhibition of TNF-α and/or its receptor.

Electrochemical sensing: A prognostic tool in the fight against COVID-19

The COVID-19 pandemic has devastated the world, despite all efforts in infection control and treatment/vaccine development. Hospitals are currently overcrowded, with health statuses of patients often being hard to gauge. Therefore, methods for determining infection severity need to be developed so that high-risk patients can be prioritized, resources can be efficiently distributed, and fatalities can be prevented. Electrochemical prognostic biosensing of various biomarkers may hold promise in solving these problems as they are low-cost and provide timely results. Therefore, we have reviewed the literature and extracted the most promising biomarkers along with their most favourable electrochemical sensors. The biomarkers discussed in this paper are C-reactive protein (CRP), interleukins (ILs), tumour necrosis factor alpha (TNFα), interferons (IFNs), glutamate, breath pH, lymphocytes, platelets, neutrophils and D-dimer. Metabolic syndrome is also discussed as comorbidity for COVID-19 patients, as it increases infection severity and raises chances of becoming infected. Cannabinoids, especially cannabidiol (CBD), are discussed as a potential adjunct therapy for COVID-19 as their medicinal properties may be desirable in minimizing the neurodegenerative or severe inflammatory damage caused by severe COVID-19 infection. Currently, hospitals are struggling to provide adequate care; thus, point-of-care electrochemical sensor development needs to be prioritized to provide an approximate prognosis for hospital patients. During and following the immediate aftermath of the pandemic, electrochemical sensors can also be integrated into wearable and portable devices to help patients monitor recovery while returning to their daily lives. Beyond the COVID-19 pandemic, these sensors will also prove useful for monitoring inflammation-based diseases such as cancer and cardiovascular disease.

Astaxanthin suppresses lipopolysaccharide‑induced myocardial injury by regulating MAPK and PI3K/AKT/mTOR/GSK3β signaling

Cardiac dysfunction is a significant manifestation of sepsis and it is associated with the prognosis of the disease. Astaxanthin (ATX) has been discovered to serve a variety of pharmacological effects, including anti‑inflammatory, antioxidant and antiapoptotic properties. The present study aimed to investigate the role and mechanisms of ATX in sepsis‑induced myocardial injury. Male C57BL/6 mice were divided into three groups (15 mice per group): Control group, lipopolysaccharide (LPS) group and LPS + ATX group. The cardiac dysfunction model was induced through an intraperitoneal injection of LPS (10 mg/kg) and ATX (40 mg/kg) was administered to the LPS + ATX group by intraperitoneal injection 30 min following the administration of LPS. All animals were sacrificed after 24 h. Inflammatory cytokine levels in the serum were detected using ELISAs, and cardiac B‑type natriuretic peptide (BNP) levels were analyzed using western blot analysis and reverse transcription‑quantitative PCR. Furthermore, the extent of myocardial injury was evaluated using pathological analysis, and cardiomyocyte apoptosis was analyzed using a TUNEL assay, in addition to determining the expression levels of Bcl‑2 and Bax. The expression levels of proteins involved in the mitogen activated protein kinase (MAPK) and PI3K/AKT signaling pathways were also analyzed using western blot analysis. ATX significantly suppressed the LPS‑induced increased production of TNF‑α and IL‑6 and suppressed the protein expression levels of BNP, Bax and Bcl‑2 to normal levels. ATX also prevented the histopathological changes to the myocardial tissue and reduced the extent of necrosis. Furthermore, the treatment with ATX suppressed the LPS‑activated MAPK and PI3K/AKT signaling. ATX additionally exerted a protective effect on cardiac dysfunction caused by sepsis by inhibiting MAPK and PI3K/AKT signaling.

The molecular mechanisms associated with the physiological responses to inflammation and oxidative stress in cardiovascular diseases

The complex physiological signal transduction networks that respond to the dual challenges of inflammatory and oxidative stress are major factors that promote the development of cardiovascular pathologies. These signaling networks contribute to the development of age-related diseases, suggesting crosstalk between the development of aging and cardiovascular disease. Inhibition and/or attenuation of these signaling networks also delays the onset of disease. Therefore, a concept of targeting the signaling networks that are involved in inflammation and oxidative stress may represent a novel treatment paradigm for many types of heart disease. In this review, we discuss the molecular mechanisms associated with the physiological responses to inflammation and oxidative stress especially in heart failure with preserved ejection fraction and emphasize the nature of the crosstalk of these signaling processes as well as possible therapeutic implications for cardiovascular medicine.

Mechanisms for the transition from physiological to pathological cardiac hypertrophy

The heart is capable of responding to stressful situations by increasing muscle mass, which is broadly defined as cardiac hypertrophy. This phenomenon minimizes ventricular wall stress for the heart undergoing a greater than normal workload. At initial stages, cardiac hypertrophy is associated with normal or enhanced cardiac function and is considered to be adaptive or physiological; however, at later stages, if the stimulus is not removed, it is associated with contractile dysfunction and is termed as pathological cardiac hypertrophy. It is during physiological cardiac hypertrophy where the function of subcellular organelles, including the sarcolemma, sarcoplasmic reticulum, mitochondria, and myofibrils, may be upregulated, while pathological cardiac hypertrophy is associated with downregulation of these subcellular activities. The transition of physiological cardiac hypertrophy to pathological cardiac hypertrophy may be due to the reduction in blood supply to hypertrophied myocardium as a consequence of reduced capillary density. Oxidative stress, inflammatory processes, Ca2+-handling abnormalities, and apoptosis in cardiomyocytes are suggested to play a critical role in the depression of contractile function during the development of pathological hypertrophy.

Effects of cardiopulmonary bypass on the development of lymphopenia and sepsis after cardiac surgery in children with congenital cardiopathy

The objective of the present study was to investigate whether lymphopenia occurring after heart surgery with cardiopulmonary bypass (CPB) is related to apoptosis and or sepsis in children. The design was a prospective cohort study in a third level care hospital in Mexico City. In total, 68 children (31 girls and 37 boys) with congenital cardiopathy who needed corrective cardiac surgery with or without CPB were included. The samples were obtained from central blood before, immediately after and 24 h after surgery. Complete blood counts and lymphocyte apoptosis were analyzed. Systemic inflammatory response syndrome (SIRS), sepsis and the type of microorganism were recorded. A total of 53 patients received CPB and 15 did not. Lymphocyte count decreased after surgery in both groups (P<0.001). However, neutrophil count increased markedly in both groups. Apoptosis of B (CD19⁺) lymphocytes was higher in the non-CPB group (14, 2 and 21% before, immediately after and 24 h after surgery, respectively) than the CPB group (0, 2 and 3%, respectively), but apoptosis of cytotoxic T lymphocytes (CD8⁺) was higher in the CPB group (5, 4 and 3% before, immediately after and 24 h after surgery, respectively) than in the non-CPB group (2, 3 and 2%, respectively). However, the extent of apoptosis of T and B lymphocytes after surgery did not differ between groups. The CPB group had more complications than the non-CPB group [38 (71.7%) vs. 9 (60.0%)]. In conclusion, the decrease in lymphocyte count may be related to apoptosis of cytotoxic T lymphocytes in children receiving cardiac surgery with CPB and to apoptosis of B lymphocytes in those not receiving CPB. The decreased lymphocyte counts in both groups suggested that CPB is not the main cause of this decrease. Children who received CPB during surgery had more complications, such as sepsis and cardiogenic shock than did those who did not receive CPB.

SDF-1 induces TNF-mediated apoptosis in cardiac myocytes

Chemokines are small secreted proteins with chemoattractant properties that play a key role in inflammation. One such chemokine, Stromal cell-derived factor-1 (SDF-1) also known as CXCL12, and its receptor, CXCR4, are expressed and functional in cardiac myocytes. SDF-1 both stimulates and enhances the cellular signal which attracts potentially beneficial stem cells for tissue repair within the ischemic heart. Paradoxically however, this chemokine is known to act in concert with the inflammatory cytokines of the innate immune response which contributes to cellular injury through the recruitment of inflammatory cells during ischemia. In the present study, we have demonstrated that SDF-1 has dose dependent effects on freshly isolated cardiomyocytes. Using Tunnel and caspase 3-activation assays, we have demonstrated that the treatment of isolated adult rat cardiac myocyte with SDF-1 at higher concentrations (pathological concentrations) induced apoptosis. Furthermore, ELISA data demonstrated that the treatment of isolated adult rat cardiac myocyte with SDF-1 at higher concentrations upregulated TNF-α protein expression which directly correlated with subsequent apoptosis. There was a significant reduction in SDF-1 mediated apoptosis when TNF-α expression was neutralized which suggests that SDF-1 mediated apoptosis is TNF-α-dependent. The fact that certain stimuli are capable of driving cardiomyocytes into apoptosis indicates that these cells are susceptible to clinically relevant apoptotic triggers. Our findings suggest that the elevated SDF-1 levels seen in a variety of clinical conditions, including ischemic myocardial infarction, may either directly or indirectly contribute to cardiac cell death via a TNF-α mediated pathway. This highlights the importance of this receptor/ligand in regulating the cardiomyocyte response to stress conditions.

The extract from Agkistrodon halys venom protects against lipopolysaccharide (LPS)-induced myocardial injury

BACKGROUND

Snake venoms contain various bioactive constituents which possess potential therapeutic effects. The aim of this work was to investigate the effect of the extract from Agkistrodon halys venom on lipopolysaccharide (LPS)-induced myocardial injury.

METHODS

Thirty male Sprague-Dawley rats were randomly assigned to three groups (10 rats per group): control group, LPS group and LPS + extract group. Rats in control and the LPS groups were intravenously injected with sterile saline solution, and rats in the LPS + extract group with the extract. After 2 h, rats of the control group were intraperitoneally injected sterile saline solution, and rats in the LPS and the LPS + extract groups were treated with LPS (20 mg per kg body weight). Levels of creatine kinase (CK) and lactate dehydrogenase (LDH) in serum were determined. Anti-inflammation of the extract was analyzed via determination of TNF-α and IL-6 in serum, and expression of TNF-α, IL-6, COX-2 and p-ERK protein in hearts. Heme oxygenase-1 (HO-1) and p-NF-κB protein expression in hearts, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level in serum were used to evaluate the anti-oxidative properties of the extract.

RESULTS

Extract pretreatment significantly decreased the level of serum CK and LDH, reduced the generation of inflammatory cytokines such as TNF-α and IL-6, and also reduced serum level of MDA in the LPS + extract group compared with the LPS group. In addition, the extract increased SOD activity in serum, HO-1 protein expression in hearts, and decreased TNF-α, IL-6, COX-2, p-NF-κB and p-ERK1/2 protein expression.

CONCLUSION

Our results suggested that beneficial effect of this extract might be associated with an improved anti-oxidation and anti-inflammatory effect via downregulation of NF-κB/COX-2 signaling by activating HO-1/CO in hearts.

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

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

Cardiovascular inflammation: RNA takes the lead

Inflammation has recently gained tremendous attention as a key contributor in several chronic diseases. While physiological inflammation is essential to counter a wide variety of damaging stimuli and to improve wound healing, dysregulated inflammation such as in the myocardium and vasculature can promote cardiovascular diseases. Given the high severity, prevalence, and economic burden of these diseases, understanding the factors involved in the regulation of physiological inflammation is essential. Like other complex biological phenomena, RNA-based processes are emerging as major regulators of inflammatory responses. Among such processes are cis-regulatory elements in the mRNA of inflammatory genes, noncoding RNAs directing the production or localization of inflammatory cytokines/chemokines, or pathogenic RNA driving inflammatory responses. In this review, we describe several specific RNA-based molecular mechanisms by which physiological inflammation pertaining to cardiovascular diseases is regulated. These include the role of AU-rich element-containing mRNAs, long non-coding RNAs, microRNAs, and viral RNAs.

Gender-Dependent Alteration of Ca2+ and TNFα Signaling in db/db Mice, an Obesity-Linked Type 2 Diabetic Model

Cardiovascular complications are the primary death cause in type 2 diabetes, where inflammation can play a role. We, and others, have previously shown that, in diabetic cardiomyopathy, cardiac dysfunction is associated with Ca²⁺ mishandling. It is possible that diabetic cardiomyopathy differently affects men and women, as the latter present higher risk to develop heart failure and a higher plasmatic level of the pro-inflammatory cytokine, tumor necrosis factor alpha (TNFα), than men. However, the gender-dependent regulation of Ca²⁺ signaling in diabetes and its relationship with TNFα signaling are still unclear. Here, we analyzed TNFα signaling pathway and its role in Ca²⁺ signaling dysfunction in male and female rodent models of type 2 diabetes linked to obesity (db/db mice) using confocal microscopy in freshly isolated cardiomyocytes. TNFα increased [Ca²⁺]_i transient amplitude and accelerated its decay without affecting SR Ca²⁺ load or Ca²⁺ spark frequency in cells from control mice. All TNFα effects on Ca²⁺ handling were prevented by the inhibition of the ceramidase and the phospholipase A2 (PLA2). While the plasmatic level of TNFα was similar in male and female db/db mice, only male db/db hearts over-expressed both TNFα converting enzyme (TACE) and the protective TNFα receptors 2 (TNF-R2). TNFα receptor 1 (TNF-R1) expression, involved in negative inotropic response of TNFα, was unchanged in both male and female db/db mice compared to controls. We found that male db/db mice cardiomyocytes presented a decrease in [Ca²⁺]_i transient amplitude associated to a drop of sarcoplasmic reticulum Ca²⁺ load, not seen in female db/db mice. Interestingly, sustained incubation with TNFα did not restored Ca²⁺ signaling alteration observed in male db/db mice but still induces an increase in Ca²⁺ spark frequency as seen in control littermates. In cardiomyocytes from female db/db mice, TNFα had no visible effects on Ca²⁺ handling. In conclusion, our study shows that the alteration of Ca²⁺ signaling and TNFα, seen in db/db mice, is gender specific presenting an increase in TNFα cardio-protective pathway in male mice.

Effect of atorvastatin on oxidative stress and inflammation markers in myxomatous mitral valve disease in dogs: A comparison of subclinical and clinical stages

Myxomatous mitral valve disease (MMVD) is the most common acquired cardiac disorder found in dogs. The disease process can lead to heart failure (HF) and has been found to be associated with oxidative stress and inflammation. Statins exert antioxidant and anti-inflammatory effects in human HF patients. However, the beneficial effects of statins in MMVD dogs are still unclear. Thirty MMVD dogs were enrolled in the study and were divided into two groups: MMVD without HF dogs (n = 15) and MMVD with HF dogs (n = 15). Atorvastatin (8 mg kg^-1  day^-1 ) was administered orally to all dogs for 4 weeks. All dogs underwent physical examination and cardiac examination at the beginning and end of the experiment, including baseline values for hematology, blood chemistry profile, lipid profile, N-terminal pro B-type natriuretic peptide, oxidative stress marker (8-isoprostane), and inflammatory marker (tumor necrosis factor alpha). The results showed that atorvastatin reduced plasma cholesterol levels in both groups. In addition, plasma concentrations of 8-isoprostane, tumor necrosis factor alpha, and N-terminal pro B-type natriuretic peptide were significantly lower after atorvastatin administration, but only in MMVD dogs in the HF group. Atorvastatin found to be associated with possible antioxidant and inflammatory effects in dogs with HF secondary to MMVD. The potential benefits of statins in dogs with HF merits further investigation in larger, placebo-controlled studies.

Bimodal Function of Anti-TNF Treatment: Shall We Be Concerned about Anti-TNF Treatment in Patients with Rheumatoid Arthritis and Heart Failure?

Treatment with anti-TNF-α (tumor necrosis factor), one of the pivotal cytokines, was introduced to clinical practice at the end of last century and revolutionized the treatment of rheumatoid arthritis (RA) as well as many other inflammatory conditions. Such a treatment may however bring many safety issues regarding infections, tuberculosis, as well as cardiovascular diseases, including heart failure. Given the central role of proinflammatory cytokines in RA, atherosclerosis, and congestive heart failure (CHF), such a treatment might result in better control of the RA process on the one side and improvement of heart function on the other. Unfortunately, at the beginning of this century two randomized controlled trials failed to show any benefit of anti-TNF treatment in patients with heart failure (HF), suggesting direct negative impact of the treatment on morbidity and mortality in HF patients. As a result the anti-TNF treatment is contraindicated in all patients with heart failure and a substantial portion of patients with RA and impaired heart function are not able to benefit from the treatment. The role of TNF in CHF and RA differs substantially with regard to the source and pathophysiological function of the cytokine in both conditions, therefore negative data from CHF studies should be interpreted with caution. At least some of RA patients with heart failure may benefit from anti-TNF treatment, as it results not only in the reduction of inflammation but also contributes significantly to the improvement of cardiac function. The paper addresses the epidemiological data of safety of anti-TNF treatment in RA patients with the special emphasis to basic pathophysiological mechanisms via which TNF may act differently in both diseases.

Effect of Hexadecyl Azelaoyl Phosphatidylcholine on Cardiomyocyte Apoptosis in Myocardial Ischemia-Reperfusion Injury: A Hypothesis

Reperfusion after myocardial ischemia can induce cardiomyocyte death, known as myocardial reperfusion injury. The pathophysiology of the process of reperfusion suggests the confluence multiple pathways. Recent studies have focused on the inflammatory response, which is considered to be the main mechanism during the process of myocardial ischemia-reperfusion injury and can cause cardiomyocyte apoptosis. Peroxisome proliferator-activated receptors gamma activated by endogenous ligands and exogenous ligand can decrease the inflammatory response in cardiomyocytes. Thiazolidinediones are synthetic, high-affinity, selective ligands for peroxisome proliferator-activated receptors gamma, and can inhibit the inflammatory response, decrease myocardial infarct size, and protect cardiac function. However, thiazolidinediones, including rosiglitazone and pioglitazone, can also contribute to adverse cardiovascular events such as congestive heart failure. Therefore, there are some limitations to the use of thiazolidinediones. Most endogenous ligands were of low affinity until hexadecyl azelaoyl phosphatidylcholine was identified as a high-affinity ligand and agonist for peroxisome proliferator-activated receptors gamma. Hexadecyl azelaoyl phosphatidylcholine binds recombinant peroxisome proliferator-activated receptors with an affinity (Kd(app) ≈40 nM) which is equivalent to rosiglitazone. Therefore, hexadecyl azelaoyl phosphatidylcholine is a specific peroxisome proliferator-activated receptors gamma agonist. Given these findings, we hypothesized that the use of hexadecyl azelaoyl phosphatidylcholine can activate the peroxisome proliferator-activated receptors gamma signal pathways and prevent the inflammatory response process of myocardial ischemia-reperfusion injury, with reduced cardiomyocyte apoptosis and death.

Serum levels of interleukin-6 are linked to the severity of the disease caused by Andes Virus

Andes virus (ANDV) is the etiological agent of hantavirus cardiopulmonary syndrome in Chile. In this study, we evaluated the profile of the pro-inflammatory cytokines IL-1β, IL-12p70, IL-21, TNF-α, IFN-γ, IL-10 and IL-6 in serum samples of ANDV-infected patients at the time of hospitalization. The mean levels of circulating cytokines were determined by a Bead-Based Multiplex assay coupled with Luminex detection technology, in order to compare 43 serum samples of healthy controls and 43 samples of ANDV-infected patients that had been categorized according to the severity of disease. When compared to the controls, no significant differences in IL-1β concentration were observed in ANDV-infected patients (p = 0.9672), whereas levels of IL-12p70 and IL-21 were significantly lower in infected cases (p = <0.0001). Significantly elevated levels of TNF-α, IFN-γ, IL-10, and IL-6 were detected in ANDV-infected individuals (p = <0.0001, 0.0036, <0.0001, <0.0001, respectively). Notably, IL-6 levels were significantly higher (40-fold) in the 22 patients with severe symptoms compared to the 21 individuals with mild symptoms (p = <0.0001). Using multivariate regression models, we show that IL-6 levels has a crude OR of 14.4 (CI: 3.3–63.1). In conclusion, the serum level of IL-6 is a significant predictor of the severity of the clinical outcome of ANDV-induced disease.

Andes virus (ANDV) causes hantavirus cardiopulmonary syndrome (HCPS) that is characterized by the development of vascular leakage syndrome, eventually leading to massive pulmonary edema, shock and, in many cases, death. To date, no FDA-approved immunotherapeutics, specific antivirals, or vaccines are available for use against HCPS. Patient survival rates hinge largely on early virus diagnosis, hospital admission and aggressive pulmonary and hemodynamic support in an intensive care unit. Individual host factors associated with the outcome of an ANDV infection are poorly known, and such knowledge could allow the disease progression of hospitalized patients to be predicted, resulting in individualized treatment. In this study, we show that serum levels of IL-6 at the time of hospitalization in ANDV-infected patients are associated with the severity of the clinical outcome of ANDV-induced disease. Therefore, these finding suggest that determining IL-6 levels at the time of admission to the hospital could be useful to predict the progression of ANDV-induced disease.

TNF-α stimulates endothelial palmitic acid transcytosis and promotes insulin resistance

Persistent elevation of plasma TNF-α is a marker of low grade systemic inflammation. Palmitic acid (PA) is the most abundant type of saturated fatty acid in human body. PA is bound with albumin in plasma and could not pass through endothelial barrier freely. Albumin-bound PA has to be transported across monolayer endothelial cells through intracellular transcytosis, but not intercellular diffusion. In the present study, we discovered that TNF-α might stimulate PA transcytosis across cardiac microvascular endothelial cells, which further impaired the insulin-stimulated glucose uptake by cardiomyocytes and promoted insulin resistance. In this process, TNF-α-stimulated endothelial autophagy and NF-κB signaling crosstalk with each other and orchestrate the whole event, ultimately result in increased expression of fatty acid transporter protein 4 (FATP4) in endothelial cells and mediate the increased PA transcytosis across microvascular endothelial cells. Hopefully the present study discovered a novel missing link between low grade systemic inflammation and insulin resistance.

CaMKIIδ subtypes differentially regulate infarct formation following ex vivo myocardial ischemia/reperfusion through NF-κB and TNF-α

Deletion of Ca2+/calmodulin-dependent protein kinase II delta (CaMKIIδ) has been shown to protect against in vivo ischemia/reperfusion (I/R) injury. It remains unclear which CaMKIIδ isoforms and downstream mechanisms are responsible for the salutary effects of CaMKIIδ gene deletion. In this study we sought to compare the roles of the CaMKIIδB and CaMKIIδC subtypes and the mechanisms by which they contribute to ex vivo I/R damage. WT, CaMKIIδKO, and mice expressing only CaMKIIδB or δC were subjected to ex vivo global ischemia for 25min followed by reperfusion. Infarct formation was assessed at 60min reperfusion by triphenyl tetrazolium chloride (TTC) staining. Deletion of CaMKIIδ conferred significant protection from ex vivo I/R. Re-expression of CaMKIIδC in the CaMKIIδKO background reversed this effect and exacerbated myocardial damage and dysfunction following I/R, while re-expression of CaMKIIδB was protective. Selective activation of CaMKIIδC in response to I/R was evident in a subcellular fraction enriched for cytosolic/membrane proteins. Further studies demonstrated differential regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and tumor necrosis factor alpha (TNF-α) expression by CaMKIIδB and CaMKIIδC. Selective activation of CaMKIIδC was also observed and associated with NF-κB activation in neonatal rat ventricular myocytes (NRVMs) subjected to oxidative stress. Pharmacological inhibition of NF-κB or TNF-α significantly ameliorated infarct formation in WT mice and those that re-express CaMKIIδC, demonstrating distinct roles for CaMKIIδ subtypes in I/R and implicating acute activation of CaMKIIδC and NF-κB in the pathogenesis of reperfusion injury.

TNF/Ang-II synergy is obligate for fibroinflammatory pathology, but not for changes in cardiorenal function

Angiotensin‐II (Ang‐II) infusion is associated with the development of interstitial fibrosis in both heart and kidney as a result of chemokine‐dependent uptake of monocytes and subsequent development of myeloid fibroblasts. This study emphasizes on the synergistic role of tumor necrosis factor (TNF) on the time course of Ang‐II‐induced fibrosis and inflammation in heart and kidney. In wild‐type (WT) hearts, Ang‐II‐induced fibrosis peaked within 1 week of infusion and remained stable over a 6‐week period, while the myeloid fibroblasts disappeared; TNF receptor‐1‐knockout (TNFR1‐KO) hearts did not develop a myeloid response or cardiac fibrosis during this time. WT hearts developed more accelerated cardiac hypertrophy and remodeling than TNFR1‐KO. In the kidney, 1‐week Ang‐II infusion did not evoke a fibrotic response; however, after 6 weeks, WT kidneys displayed modest but significant tubulointerstitial collagen deposition associated with the appearance of myeloid cells and profibrotic gene activation. Renal fibrosis was not seen in Ang‐II‐infused TNFR1‐KO. By contrast, while hypertension increased and cardiac function decreased more slowly in TNFR1‐KO than WT, they were equivalently abnormal at 6 weeks. Similarly, serum markers for renal dysfunction were not different after 6 weeks. In conclusion, Ang‐II infusion initiated fibroinflammatory responses with different time courses in heart and kidney, both requiring TNFR1 signaling, and both associated with monocyte‐derived myeloid fibroblasts. TNFR1 deletion obviated the fibroinflammatory effects of Ang‐II, but did not alter changes in blood pressure and cardiorenal function after 6 weeks. Thus, the synergy of TNF with Ang‐II targets the fibroinflammatory component of Ang‐II signaling.

The protective effect of trimetazidine on myocardial ischemia/reperfusion injury through activating AMPK and ERK signaling pathway

INTRODUCTION

Trimetazidine (TMZ) is an anti-anginal drug that has been widely used in Europe and Asia. The TMZ can optimize energy metabolism via inhibition of long-chain 3-ketoacyl CoA thiolase (3-KAT) in the heart, with subsequent decrease in fatty acid oxidation and stimulation of glucose oxidation. However, the mechanism by which TMZ aids in cardioprotection against ischemic injury has not been characterized. AMP-activated protein kinase (AMPK) is an energy sensor that controls ATP supply from substrate metabolism and protects heart from energy stress. TMZ changes the cardiac AMP/ATP ratio by modulating fatty acid oxidation, thereby triggering AMPK signaling cascade that contributes to the protection of the heart from ischemia/reperfusion (I/R) injury.

METHODS

The mouse model of in vivo regional ischemia and reperfusion by the ligation of the left anterior descending coronary artery (LAD) was used for determination of myocardial infarction. The infarct size was compared between C57BL/6J WT mice and AMPK kinase dead (KD) transgenic mice with or without TMZ treatment. The ex vivo working heart perfusion system was used to monitor the effect of TMZ on glucose oxidation and fatty acid oxidation in the heart.

RESULTS

TMZ treatment significantly stimulates cardiac AMPK and extracellular signal-regulated kinase (ERK) signaling pathways (p<0.05 vs. vehicle group). The administration of TMZ reduces myocardial infarction size in WT C57BL/6J hearts, the reduction of myocardial infarction size by TMZ in AMPK KD hearts was significantly impaired versus WT hearts (p<0.05). Intriguingly, the administration of ERK inhibitor, PD98059, to AMPK KD mice abolished the cardioprotection of TMZ against I/R injury. The ex vivo working heart perfusion data demonstrated that TMZ treatment significantly activates AMPK signaling and modulating the substrate metabolism by shifting fatty acid oxidation to glucose oxidation during reperfusion, leading to reduction of oxidative stress in the I/R hearts. Therefore, both AMPK and ERK signaling pathways mediate the cardioprotection of TMZ against ischemic injury. The metabolic benefits of TMZ for angina patients could be due to the activation of energy sensor AMPK in the heart by TMZ administration.

Protective Effects of HDL Against Ischemia/Reperfusion Injury

Several lines of evidence suggest that, besides being a strong independent predictor of the occurrence of primary coronary events, a low plasma high density lipoprotein (HDL) cholesterol level is also associated with short- and long-term unfavorable prognosis in patients, who have recovered from a myocardial infarction, suggesting a direct detrimental effect of low HDL on post-ischemic myocardial function. Experiments performed in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury have clearly shown that HDL are able to preserve cardiac function when given before ischemia or at reperfusion; the protective effects of HDL against I/R injury have been also confirmed in other tissues and organs, as brain and hind limb. HDL were shown to act on coronary endothelial cells, by limiting the increase of endothelium permeability and promoting vasodilation and neoangiogenesis, on white blood cells, by reducing their infiltration into the ischemic tissue and the release of pro-inflammatory and matrix-degrading molecules, and on cardiomyocytes, by preventing the activation of the apoptotic cascade. Synthetic HDL retains the cardioprotective activity of plasma-derived HDL and may become a useful adjunctive therapy to improve clinical outcomes in patients with acute coronary syndromes or undergoing coronary procedures.

Allopurinol Protects against Ischemia/Reperfusion-Induced Injury in Rat Urinary Bladders

Bladder ischemia-reperfusion (I/R) injury results in the generation of reactive oxygen species (ROS) and markedly elevates the risk of lower urinary tract symptoms (LUTS). Allopurinol is an inhibitor of xanthine oxidase (XO) and thus can serve as an antioxidant that reduces oxidative stress. Here, a rat model was used to assess the ability of allopurinol treatment to ameliorate the deleterious effects of urinary bladder I/R injury. I/R injury reduced the in vitro contractile responses of longitudinal bladder strips, elevated XO activity in the plasma and bladder tissue, increased the bladder levels of tumor necrosis factor-α (TNF-α), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase, reduced the bladder levels of extracellular regulated kinase (ERK), and decreased and increased the bladder levels of Bcl-2 and Bax, respectively. I/R injury also elevated lipid peroxidation in the bladder. Allopurinol treatment in the I/R injury was generated significantly ameliorating all I/R-induced changes. Moreover, an in situ fluorohistological approach also showed that allopurinol reduces the generation of intracellular superoxides enlarged by I/R injury. Together, the beneficial effects of allopurinol reducing ROS production may be mediated by normalizing the activity of the ERK, JNK, and Bax/Bcl-2 pathways and by controlling TNF-α expression.

Addressing the Global Burden of Trauma in Major Surgery

Despite a technically perfect procedure, surgical stress can determine the success or failure of an operation. Surgical trauma is often referred to as the "neglected step-child" of global health in terms of patient numbers, mortality, morbidity, and costs. A staggering 234 million major surgeries are performed every year, and depending upon country and institution, up to 4% of patients will die before leaving hospital, up to 15% will have serious post-operative morbidity, and 5-15% will be readmitted within 30 days. These percentages equate to around 1000 deaths and 4000 major complications every hour, and it has been estimated that 50% may be preventable. New frontline drugs are urgently required to make major surgery safer for the patient and more predictable for the surgeon. We review the basic physiology of the stress response from neuroendocrine to genomic systems, and discuss the paucity of clinical data supporting the use of statins, beta-adrenergic blockers and calcium-channel blockers. Since cardiac-related complications are the most common, particularly in the elderly, a key strategy would be to improve ventricular-arterial coupling to safeguard the endothelium and maintain tissue oxygenation. Reduced O2 supply is associated with glycocalyx shedding, decreased endothelial barrier function, fluid leakage, inflammation, and coagulopathy. A healthy endothelium may prevent these "secondary hit" complications, including possibly immunosuppression. Thus, the four pillars of whole body resynchronization during surgical trauma, and targets for new therapies, are: (1) the CNS, (2) the heart, (3) arterial supply and venous return functions, and (4) the endothelium. This is termed the Central-Cardio-Vascular-Endothelium (CCVE) coupling hypothesis. Since similar sterile injury cascades exist in critical illness, accidental trauma, hemorrhage, cardiac arrest, infection and burns, new drugs that improve CCVE coupling may find wide utility in civilian and military medicine.

Genetic and Environmental Factors Affecting TNF-α Responses in Relation to Sudden Infant Death Syndrome

Dysregulation of the inflammatory responses has been suggested to contribute to the events leading to sudden infant deaths. Our objectives were (1) to analyze a single nucleotide polymorphism (SNP) associated with high levels of tumor necrosis factor-α (TNF-α) responses, TNF G-308A, in sudden infant death syndrome (SIDS) infants, SIDS and control parents, and ethnic groups with different incidences of SIDS; (2) the effects of two risk factors for SIDS, cigarette smoke and virus infection, on TNF-α responses; and (3) to assess effects of genotype, cigarette smoke, and gender on TNF-α responses to bacterial toxins identified in SIDS infants. TNF G-308A genotypes were determined by real-time polymerase chain reaction for SIDS infants from Australia, Germany, and Hungary; parents of SIDS infants and their controls; and populations with high (Aboriginal Australian), medium (Caucasian), and low (Bangladeshi) SIDS incidences. Leukocytes from Caucasian donors were stimulated in vitro with endotoxin or toxic shock syndrome toxin-1 (TSST-1). TNF-α responses were measured by L929 bioassay (IU/ml) and assessed in relation to genotype, smoking status, and gender. There was a significantly higher proportion of the minor allele AA genotype among Australian SIDS infants (6/24, 24%) compared to 3/62 (4.8%) controls (p = 0.03). There were no significant differences in TNF-α responses by TNF G-308A genotypes when assessed in relation to smoking status or gender. Given the rarity of the TNF G-308A A allele in Caucasian populations, the finding that 24% of the Australian SIDS infants tested had this genotype requires further investigation and cautious interpretation. Although non-smokers with the AA genotype had higher TNFα responses to both TSST-1 and endotoxin, there were too few subjects with this rare allele to obtain statistically valid results. No effects of genotype, smoking, or gender were observed for TNF-α responses to these toxins.

TNF-α antagonism ameliorates myocardial ischemia-reperfusion injury in mice by upregulating adiponectin

Tumor necrosis factor-α (TNF-α) antagonism alleviates myocardial ischemia-reperfusion (MI/R) injury. However, the mechanisms by which the downstream mediators of TNF-α change after acute antagonism during MI/R remain unclear. Adiponectin (APN) exerts anti-ischemic effects, but it is downregulated during MI/R. This study was conducted to investigate whether TNF-α is responsible for the decrease of APN, and whether antagonizing TNF-α affects MI/R injury by increasing APN. Male adult wild-type (WT), APN knockout (APN KO) mice, and those with cardiac knockdowns of APN receptors via siRNA injection were subjected to 30 min of MI followed by reperfusion. The TNF-α antagonist etanercept or globular domain of APN (gAD) was injected 10 min before reperfusion. Etanercept ameliorated MI/R injury in WT mice as evidenced by improved cardiac function, and reduced infarct size and cardiomyocyte apoptosis. APN concentrations were augmented in response to etanercept, followed by an increase in AMP-activated protein kinase phosphorylation. Etanercept still increased cardiac function and reduced infarct size and apoptosis in both APN KO and APN receptors knockdown mice. However, its potential was significantly weakened in these mice compared with the WT mice. TNF-α is responsible for the decrease in APN during MI/R. The cardioprotective effects of TNF-α neutralization are partially due to the upregulation of APN. The results provide more insight into the TNF-α-mediated signaling effects during MI/R and support the need for clinical trials to validate the efficacy of acute TNF-α antagonism in the treatment of MI/R injury.

Exercise ameliorates high fat diet induced cardiac dysfunction by increasing interleukin 10

Increasing evidence suggests that a sedentary lifestyle and a high fat diet (HFD) leads to cardiomyopathy. Moderate exercise ameliorates cardiac dysfunction, however underlying molecular mechanisms are poorly understood. Increased inflammation due to induction of pro-inflammatory cytokine such as tumor necrosis factor-alpha (TNF-α) and attenuation of anti-inflammatory cytokine such as interleukin 10 (IL-10) contributes to cardiac dysfunction in obese and diabetics. We hypothesized that exercise training ameliorates HFD- induced cardiac dysfunction by mitigating obesity and inflammation through upregulation of IL-10 and downregulation of TNF-α. To test this hypothesis, 8 week old, female C57BL/6J mice were fed with HFD and exercised (swimming 1 h/day for 5 days/week for 8 weeks). The four treatment groups: normal diet (ND), HFD, HFD + exercise (HFD + Ex) and ND + Ex were analyzed for mean body weight, blood glucose level, TNF-α, IL-10, cardiac fibrosis by Masson Trichrome, and cardiac dysfunction by echocardiography. Mean body weights were increased in HFD but comparatively less in HFD + Ex. The level of TNF-α was elevated and IL-10 was downregulated in HFD but ameliorated in HFD + Ex. Cardiac fibrosis increased in HFD and was attenuated by exercise in the HFD + Ex group. The percentage ejection fraction and fractional shortening were decreased in HFD but comparatively increased in HFD + Ex. There was no difference between ND and ND + Ex for the above parameters except an increase in IL-10 level following exercise. Based on these results, we conclude that exercise mitigates HFD- induced cardiomyopathy by decreasing obesity, inducing IL-10, and reducing TNF-α in mice.

Sodium tanshinone IIA silate inhibits oxygen-glucose deprivation/recovery-induced cardiomyocyte apoptosis via suppression of the NF-κB/TNF-α pathway

BACKGROUND AND PURPOSE

Inhibition of apoptosis may attenuate the irreversible injury associated with reperfusion. In the current study, we focused on the cytoprotective effects and the underlying mechanism of sodium tanshinone IIA silate (STS) against damage induced by oxygen-glucose deprivation/recovery (OGD/R). in H9c2 cardiomyocytes and the underlying mechanisms.

EXPERIMENTAL APPROACH

We used a model of cardiac ischaemia/reperfusion, OGD/R in H9c2 cardiomyocytes, to assess the cardioprotective effects of STS. Apoptosis of cells was measured with Hoechst 33342-based fluorescence microscopy, and annexin V-FITC-based flow cytometry. Caspase-3 and caspase-8 activities and mitochondrial membrane potential were also measured using commercial kits. TNF-α in the cell culture supernatant fractions were measured with sandwich elisa, and protein levels assayed using Western blot.

KEY RESULTS

STS inhibited OGD/R-induced apoptosis by suppressing JNK-mediated activation of NF-κB, TNF-α expression, activation of caspase-3 and caspase-8 and the Bax/Bcl-2 ratio. Additionally, positive feedback between NF-κB and TNF-α and amplification of TNF-α were inhibited, suggesting that STS plays a protective role against apoptosis in cardiomyocytes, even upon activation of pro-inflammatory cytokines. Interestingly, the cytoprotective effects of STS on OGD/R-induced apoptosis and promotion of cell survival were attenuated after inhibition of PI3K.

CONCLUSION AND IMPLICATIONS

The inhibitory effects of STS on TNF-α and positive feedback signalling of the NF-κB/TNF-α pathways may play important roles in myocardial protection against ischaemia/reperfusion. These protective effects of STS are mediated by suppressing JNK activity through activation of the PI3K-Akt pathway.

Effect of hydrogen sulfide on inflammatory cytokines in acute myocardial ischemia injury in rats

Hydrogen sulfide (H₂S) is believed to be involved in numerous physiological and pathophysiological processes, and now it is recognized as the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide; however, the effects of H₂S on inflammatory factors in acute myocardial ischemia injury in rats have not been clarified. In the present study, sodium hydrosulfide (NaHS) was used as the H₂S donor. Thirty-six male Sprague Dawley rats were randomly divided into five groups: Sham, ischemia, ischemia + low-dose (0.78 mg/kg) NaHS, ischemia + medium-dose (1.56 mg/kg) NaHS, ischemia + high-dose (3.12 mg/kg) NaHS and ischemia + propargylglycine (PPG) (30 mg/kg). The rats in each group were sacrificed 6 h after the surgery for sample collection. Compared with the ischemia group, the cardiac damage in the rats in the ischemia + NaHS groups was significantly reduced, particularly in the high-dose group; in the ischemia + PPG group, the myocardial injury was aggravated compared with that in the ischemia group. Compared with the ischemia group, the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in the serum of rats in the ischemia + medium- and high-dose NaHS groups were significantly reduced, and the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) protein in the myocardial tissues of rats was significantly reduced. In the ischemia + PPG group, the TNF-α, IL-1β and IL-6 levels in the serum were significantly increased, the expression of ICAM-1 mRNA was increased, although without a significant difference, and the expression of NF-κB was increased. The findings of the present study provide novel evidence for the dual effects of H₂S on acute myocardial ischemia injury via the modulation of inflammatory factors.

A rapid enzymatic assay for high-throughput screening of adenosine-producing strains

Adenosine is a major local regulator of tissue function and industrially useful as precursor for the production of medicinal nucleoside substances. High-throughput screening of adenosine overproducers is important for industrial microorganism breeding. An enzymatic assay of adenosine was developed by combined adenosine deaminase (ADA) with indophenol method. The ADA catalyzes the cleavage of adenosine to inosine and NH3 , the latter can be accurately determined by indophenol method. The assay system was optimized to deliver a good performance and could tolerate the addition of inorganic salts and many nutrition components to the assay mixtures. Adenosine could be accurately determined by this assay using 96-well microplates. Spike and recovery tests showed that this assay can accurately and reproducibly determine increases in adenosine in fermentation broth without any pretreatment to remove proteins and potentially interfering low-molecular-weight molecules. This assay was also applied to high-throughput screening for high adenosine-producing strains. The high selectivity and accuracy of the ADA assay provides rapid and high-throughput analysis of adenosine in large numbers of samples.

Protection of intestinal injury during heat stroke in mice by interleukin-6 pretreatment

KEY POINTS

Heat stroke afflicts thousands of humans each year, worldwide. The immune system responds to hyperthermia exposure resulting in heat stroke by producing an array of immunological proteins, such as interleukin-6 (IL-6). However, the physiological functions of IL-6 and other cytokines in hyperthermia are poorly understood. We hypothesized that IL-6 plays a protective role in conditions of heat stroke. To test this, we gave small IL-6 supplements to mice prior to exposing them to hot environments sufficient to induce conditions of heat stroke. Pretreatment with IL-6 resulted in improved ability to withstand heat exposure in anaesthetized mice, it protected the intestine from injury, reducing the permeability of the intestinal barrier, and it attenuated the release of other cytokines involved in inflammation. The results support the hypothesis that IL-6 is a 'physiological stress hormone' that plays an important role in survival during acute life-threatening conditions such as heat stroke.

ABSTRACT

The role of interleukin-6 (IL-6) in hyperthermia and heat stroke is poorly understood. Plasma IL-6 is elevated following hyperthermia in animals and humans, and IL-6 knockout mice are more intolerant of severe hyperthermia. We evaluated the effect of IL-6 supplementation on organ injury following severe hyperthermia exposure in anaesthetized mice. Two hours prior to hyperthermia, mice were treated with 0.6 μg intraperitoneal IL-6, or identical volumes of saline in controls. Mice were anaesthetized, gavaged with FITC-dextran for measures of gastrointestinal permeability, and exposed to incremental (0.5°C every 30 min) increases in temperature. Heating stopped when maximum core temperature (Tc) of 42.4°C was attained (Tc,max). The mice recovered at room temperature (≈22°C) for 30 or 120 min, at which time plasma and tissues were collected. IL-6-treated mice, on average, required ≈25 min longer to attain Tc,max . Injury and swelling of the villi in the duodenum was present in untreated mice after 30 min of recovery. These changes were blocked by IL-6 treatment. IL-6 also reduced gastrointestinal permeability, assayed by the accumulation of FITC-dextran in plasma. Plasma cytokines were also attenuated in IL-6-treated animals, including significant reductions in TNFα, MCP-1 (CXCL2), RANTES (CCL5) and KC (CCL5). The results demonstrate that IL-6 has a protective influence on the pattern of physiological responses to severe hyperthermia, suggesting that early endogenous expression of IL-6 may provide a protection from the development of organ damage and inflammation.

Nuclear factor-κB activation inhibitor attenuates ischemia reperfusion injury and inhibits Hmgb1 expression

OBJECTIVE AND DESIGN

To investigate the effects of nuclear factor-κB activation inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) on cardiac ischemia reperfusion injury in a transplantation model.

METHODS

Hearts of C57BL/6 mice were flushed and stored in cold Bretschneider solution for 8 h and then transplanted into syngeneic recipient. Some mice were administrated intraperitoneally with DHMEQ (8 mg/kg) 1 h before reperfusion. For inhibition of Hmgb1, mice were treated with glycyrrhizin at 250 mg/kg prior to reperfusion.

RESULTS

DHMEQ decreased cardiomyocyte apoptosis and recruitment of neutrophils and macrophages. Troponin T (TnT) production on 24 h after myocardial IR injury was reduced by DHMEQ treatment. Cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts with DHMEQ treatment (IR+DHMEQ: 58.6 ± 5.75 ml/min; IR: 25.9 ± 4.1 ml/min; P < 0.05). Furthermore, DHMEQ suppressed high mobility group protein (Hmgb1) expression. And the Caspase 3 activity, the number of TUNEL-positive cardiomyocytes and infiltrated neutrophil in cardiac allograft were markedly decreased with Hmgb1 inhibitor treatment.

CONCLUSIONS

Nuclear factor-κB activation inhibitor DHMEQ attenuates ischemia reperfusion injury in a cardiac transplantation model and it may be a suitable agent for the protection of the cardiac against ischemia reperfusion injury.

Transcription of the gene encoding TNF-α is increased by IL-1β in rat and human islets and β-cell lines

Synthesis and secretion of immunomodulatory proteins, such as cytokines and chemokines, controls the inflammatory response within pancreatic islets. When this inflammation does not resolve, destruction of pancreatic islet β-cells leads to diabetes mellitus. Production of the soluble mediators of inflammation, such as TNF-α and IL-1β, from resident and invading immune cells, as well as directly from islet β-cells, is also associated with suboptimal islet transplantation outcomes. In this study, we found that IL-1β induces rapid increases in TNF-α mRNA in rat and human islets and the 832/13 clonal β-cell line. The surge in transcription of the TNF-α gene required the inhibitor of kappa B kinase beta (IκKβ), the p65 subunit of the NF-κB and a signal-specific recruitment of RNA polymerase II to the gene promoter. Of note was the increased intracellular production of TNF-α protein in a manner consistent with mRNA accumulation in response to IL-1β, but no detectable secretion of TNF-α into the media. Additionally, TNF-α specifically induces expression of CD11b, but not CD11c, on neutrophils, which could contribute to the inflammatory milieu and diabetes progression. We conclude that activation of the NF-κB pathway in pancreatic β-cells leads to rapid intracellular production of the pro-inflammatory TNF-α protein through a combination of specific histone covalent modifications and NF-κB signaling pathways.

Role of exercise training on autonomic changes and inflammatory profile induced by myocardial infarction

The cardiovascular autonomic imbalance in patients after myocardial infarction (MI) provides a significant increase in mortality rate, and seems to precede metabolic, hormonal, and immunological changes. Moreover, the reduction in the parasympathetic function has been associated with inflammatory response in different pathological conditions. Over the years, most of the studies have indicated the exercise training (ET) as an important nonpharmacological tool in the management of autonomic dysfunction and reduction in inflammatory profile after a myocardial infarction. In this work, we reviewed the effects of ET on autonomic imbalance after MI, and its consequences, particularly, in the post-MI inflammatory profile. Clinical and experimental evidence regarding relationship between alterations in autonomic regulation and local or systemic inflammation response after MI were also discussed.

TNF, acting through inducibly expressed TNFR2, drives activation and cell cycle entry of c-Kit+ cardiac stem cells in ischemic heart disease

TNF, signaling through TNFR2, has been implicated in tissue repair, a process that in the heart may be mediated by activated resident cardiac stem cells (CSCs). The objective of our study is to determine whether ligation of TNFR2 can induce activation of resident CSCs in the setting of ischemic cardiac injury. We show that in human cardiac tissue affected by ischemia heart disease (IHD), TNFR2 is expressed on intrinsic CSCs, identified as c-kit(+)/CD45(-)/VEGFR2(-) interstitial round cells, which are activated as determined by entry to cell cycle and expression of Lin-28. Wild-type mouse heart organ cultures subjected to hypoxic conditions both increase cardiac TNF expression and show induced TNFR2 and Lin-28 expression in c-kit(+) CSCs that have entered cell cycle. These CSC responses are enhanced by exogenous TNF. TNFR2(-/-) mouse heart organ cultures subjected to hypoxia increase cardiac TNF but fail to induce CSC activation. Similarly, c-kit(+) CSCs isolated from mouse hearts exposed to hypoxia or TNF show induction of Lin-28, TNFR2, cell cycle entry, and cardiogenic marker, α-sarcomeric actin (α-SA), responses more pronounced by hypoxia in combination with TNF. Knockdown of Lin-28 by siRNA results in reduced levels of TNFR2 expression, cell cycle entry, and diminished expression of α-SA. We conclude that hypoxia-induced c-kit(+) CSC activation is mediated by TNF/TNFR2/Lin-28 signaling. These observations suggest that TNFR2 signaling in resident c-kit(+) CSCs induces cardiac repair, findings which provide further understanding of the unanticipated harmful effects of TNF blockade in human IHD.

Both castration and goserelin acetate ameliorate myocardial ischemia reperfusion injury and apoptosis in male rats

Although reperfusion of an ischemic organ is essential to prevent irreversible tissue damage, it may amplify tissue injury. This study investigates the role of endogenous testosterone in myocardial ischemia reperfusion and apoptosis in male rats. Material and method. Twenty four male rats were randomized into 4 equal groups: Group (1), sham group, rats underwent the same anesthetic and surgical procedure as the control group except for LAD ligation; Group (2), Active control group, rats underwent LAD ligation; Group (3), castrated, rats underwent surgical castration, left 3wks for recovery, and then underwent LAD ligation; and Group (4), Goserelin acetate treated, rats received 3.6 mg of Goserelin 3 wks before surgery and then underwent LAD ligation. At the end of experiment, plasma cTn I, cardiac TNF-α, IL1-β, ICAM-1, and Apoptosis level were measured and histological examination was made. Results. Compared to sham group, the levels of myocardial TNF-α, IL-1β, ICAM-1, apoptosis, and plasma cTn I were significantly increased (P < 0.05) in control group and all rats showed significant myocardial injury (P < 0.05). Castration and Goserelin acetates significantly counteract the increase in myocardial levels of TNF-α, IL-1β, ICAM-1, plasma cTn I, and apoptosis (P < 0.05) and significantly reduce (P < 0.05) the severity of myocardial injury. We conclude that castration and Goserelin acetates ameliorate myocardial I/R injury and apoptosis in rats via interfering with inflammatory reactions.

Effect of ECQ on Iodoacetamide-Induced Chronic Gastritis in Rats

This study investigated effect of extract containing quercetin-3-O-β-D-glucuronopyranoside from Rumex Aquaticus Herba (ECQ) against chronic gastritis in rats. To produce chronic gastritis, the animals received a daily intra-gastric administration of 0.1 ml of 0.15% iodoacetamide (IA) solution for 7 days. Daily exposure of the gastric mucosa to IA induced both gastric lesions and significant reductions of body weight and food and water intake. These reductions recovered with treatment with ECQ for 7 days. ECQ significantly inhibited the elevation of the malondialdehyde levels and myeloperoxidase activity, which were used as indices of lipid peroxidation and neutrophil infiltration. ECQ recovered the level of glutathione, activity of superoxide dismutase (SOD), and expression of SOD-2. The increased levels of total NO concentration and iNOS expression in the IA-induced chronic gastritis were significantly reduced by treatment with ECQ. These results suggest that the ECQ has a therapeutic effect on chronic gastritis in rats by inhibitory actions on neutrophil infiltration, lipid peroxidation and various steps of reactive oxygen species (ROS) generation.

Dietary choline modulates immune responses, and gene expressions of TOR and eIF4E-binding protein2 in immune organs of juvenile Jian carp (Cyprinus carpio var. Jian)

The present work evaluates the effects of various levels of dietary choline on immune parameters, immune-related gene expression and protection against Aeromonas hydrophila (AH) in juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed with six different experimental diets containing graded levels of choline at 165 (choline-deficient control), 310, 607, 896, 1167 and 1820 mg kg(-1) diet for 65 days. At the end of the feeding trail, Fish were challenged with AH and mortalities were recorded over 17 days. Dietary choline significantly enhanced spleen and head kidney weights, spleen index, red blood cell and white blood cell counts, and intestinal Lactobacillus counts of juvenile Jian carp; whereas, intestinal Escherichia coli and A. hydrophila counts decreased. Moreover, the post-challenge survival rate, leucocyte phagocytic capacity, serum lysozyme and acid phosphatase activities, hemagglutination titer, complement 3 and 4 contents, immunoglobulin M content, and anti-AH antibody titer were significantly enhanced by choline and the lowest in choline-deficient group, while serum total iron-binding capacity was the highest in choline-deficient group. The relative gene expressions of interleukin 10 in spleen and head kidney, target of rapamycin (TOR) in spleen and eIF4E-binding protein2 (4E-BP2) in head kidney significantly increased with increasing of dietary choline up to a certain point. However, the relative gene expressions of interleukin 1β, tumor necrosis factor α and transforming growth factor β2 in spleen and head kidney, TOR in head kidney and 4E-BP2 in spleen significantly decreased. In conclusion, dietary choline improved disease resistance, enhanced the immune function, and regulated immune-related gene expression of juvenile Jian carp.