Immunomodulation: a new horizon for medical treatment of heart failure

A ceramide-1-phosphate analogue, PCERA-1, simultaneously suppresses tumour necrosis factor-alpha and induces interleukin-10 production in activated macrophages

Tight regulation of the production of the key pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha) is essential for the prevention of chronic inflammatory diseases. In vivo administration of a synthetic phospholipid, named hereafter phospho-ceramide analogue-1 (PCERA-1), was previously found to suppress lipopolysaccharide (LPS)-induced TNF-alpha blood levels. We therefore investigated the in vitro anti-inflammatory effects of PCERA-1. Here, we show that extracellular PCERA-1 potently suppresses production of the pro-inflammatory cytokine TNF-alpha in RAW264.7 macrophages, and in addition, independently and reciprocally regulates the production of the anti-inflammatory cytokine interleukin-10 (IL-10). Specificity is demonstrated by the inability of the phospholipids ceramide-1-phosphate (C1P), sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) to perform these activities. Similar TNF-alpha suppression and IL-10 induction by PCERA-1 were observed in macrophages when activated by Toll-like receptor 4 (TLR4), TLR2 and TLR7 agonists. Regulation of cytokine production is demonstrated at the mRNA and protein levels. Finally, we show that, while PCERA-1 does not block activation of nuclear factor (NF)-kappaB and mitogen-activated protein kinases by LPS, it elevates the intracellular cAMP level. In conclusion, the anti-inflammatory activity of PCERA-1 seems to be mediated by a cell membrane receptor, upstream of cAMP production, and eventually TNF-alpha suppression and IL-10 induction. Thus, identification of the PCERA-1 receptor may provide new pharmacological means to block inflammation.

The effect of cardiovascular drugs on pro-inflammatory cytokine secretion and natural killer activity of peripheral blood mononuclear cells of patients with chronic heart failure in vitro

Recent studies have shown that patients with heart failure over-express pro-inflammatory cytokines which enhance natural killer (NK) activity and negatively influence contractility and contribute to the remodeling of myocardium. The question is that how cardiovascular drugs influence on the cytokines of Peripheral Blood Mononuclear Cells (PBMCs) in Chronic Heart Failure (CHF). To study the effect of cardiovascular drugs on PBMCs-cytokines and NK activity of CHF patients. PBMCs of CHF patients/normal controls collected by Ficoll-paque density centrifugation. NK activity against K562 target cell was measured with MTT colorimetric assay. PBMCs were cultivated in RPMI/FCS, stimulated with phytohaemaglutinin (PHA). Tumor necrosis factor (TNF)-alpha interleukin (IL)-6, IL-2 and IL-1beta of culture supernatants after 24 h incubation with/without furosemide, captopril and digoxin were measured with sandwitch ELISA. Patients had higher NK activity than controls (56.9% +/- 1.6 vs 50.9% +/- 1.2, p < 0.05). NK activity of patients who already consumed Captopril/Furosemide didn't show difference with controls. Captopril (3, 1, 0.3 microg mL(-1)) and Furosemide (5, 2.5, 1.25 microg mL(-1)) caused a dose dependent inhibition in TNF-alpha compared with control (329 +/- 23, 427 +/- 15, 519 +/- 19 and 343 +/- 19, 430 +/- 14, respectively vs. 562 +/- 24 pg mL(-1) p < 0.05). Furosemide caused a dose dependent decrease in IL-6 (421 +/- 31, 534 +/- 33 vs. 662 +/- 41 pg mL(-1) p < 0.05). Captopril and Furosemide didn't show any significant effect on IL-1beta/IL-2. Digoxin had no significant effect on PBMCs-cytokines. These data suggest that the immunomodulatory effects of Captopril and Furosemide may contribute to their beneficial and no long-term adverse effects on PBMCs.

Cyclooxygenase-2 inhibitor treatment improves left ventricular function and mortality in a murine model of doxorubicin-induced heart failure

BACKGROUND

Progression of heart failure after initial myocardial injury is mediated in part by various redundant inflammatory mediators, including the widely expressed cyclooxygenase-2 (COX-2). Because COX-2 inhibitors are useful in treating many inflammation-mediated diseases, we asked whether COX-2 inhibition can attenuate heart failure progression.

METHODS AND RESULTS

Heart failure was experimentally induced in 100 mice by administration of doxorubicin (4 mg. kg(-1). wk(-1) for 6 weeks). Beginning at day 42, mice were fed daily with either COX-2 inhibitor-containing mice chow (n=50) or plain mice chow (controls; n=50). Left ventricular ejection fraction was evaluated as a measure of heart failure by a novel method of transthoracic echocardiography (with intravascular ultrasound catheters) at baseline and on days 42, 56, and 70. From baseline to study termination, left ventricular ejection fraction in COX-2 inhibitor-treated mice decreased significantly less than in control mice (9% versus 29%, P<0.01). Mortality was significantly lower for COX-2 inhibitor-treated mice than for control mice (18% versus 38%, P<0.01). These results were confirmed in a revalidation study in COX-2 inhibitor-treated mice (n=25) and controls (n=25). That study revealed that the hearts from control mice weighed roughly the same as hearts from COX-2 inhibitor-treated mice but showed more extensive signs of cardiomyopathy (as determined by pathological analysis by an independent, blinded observer) and higher levels of COX-2 proteins (as determined by immunoblotting [6442+/-1635 versus 4300+/-2408 arbitrary units, P<0.022]).

CONCLUSIONS

COX-2 inhibitors can attenuate the progression of heart failure in a murine model of doxorubicin-induced heart failure.

Vesnarinone: a differentiation-inducing anti-cancer drug

Vesnarinone has been shown to be a unique anti-proliferating, differentiation-inducing and apoptosis inducing drug against several human malignancies, including leukemia and several solid tumors. Furthermore, vesnarinone potentiates the effect of conventional cytotoxic chemotherapy or radiation therapy. Combination of differentiation-inducing therapy by vesnarinone with conventional chemotherapy or radiation therapy might be second- or third-line therapy in patients with advanced cancer. Analysis of the molecular mechanisms of the tumor differentiation therapy by vesnarinone might provide selective and targeted molecules for novel tumor dormancy therapy.

Gap junctions, homeostasis, and injury

Gap junctions (Gj) play an important role in the communication between cells of many tissues. They are composed of channels that permit the passage of ions and low molecular weight metabolites between adjacent cells, without exposure to the extracellular environment. These pathways are formed by the interaction between two hemichannels on the surface of opposing cells. These hemichannels are formed by the association of six identical subunits, named connexins (Cx), which are integral membrane proteins. Cell coupling via Gj is dependent on the specific pattern of Cx gene expression. This pattern of gene expression is altered during several pathological conditions resulting in changes of cell coupling. The regulation of Cx gene expression is affected at different levels from transcription to post translational processes during injury. In addition, Gj cellular communication is regulated by gating mechanisms. The alteration of Gj communication during injury could be rationalized by two opposite theories. One hypothesis proposes that the alteration of Gj communication attenuates the spread of toxic metabolites from the injured area to healthy organ regions. The alternative proposition is that a reduction of cellular communication reduces the loss of important cellular metabolisms, such as ATP and glucose.

Innovative drug treatments for viral and autoimmune myocarditis

Myocarditis is a common cause of cardiomyopathy and is thought to account for 25% of all cases in humans. Unfortunately, the disease is difficult to detect clinically before a myopathic process ensues. Management of myocarditis-induced heart failure includes the standard regimen of diuretics, digoxin, angiotensin-converting enzyme inhibitors, angiotensin-II receptor blockers, and beta-adrenergic blockers. The management of myocarditis itself is dependent on the etiology of the illness. Treatments that are currently under investigation include immunosuppressants, nonsteroidal antiinflammatory agents, immunoglobulins, immunomodulation, antiadrenergics, calcium-channel blockers, angiotensin-converting enzyme inhibitors, nitric oxide inhibitors (e.g., aminoguanidine), and antivirals. Despite advances in treatment, more work needs to be done in the early detection of myocarditis. Additionally, better means need to be established for distinguishing between viral and noninfectious autoimmune forms of the disease, so that appropriate treatment can be instituted.

Orosomucoid: a mortality risk factor in elderly people living in the community?

AIM

We explored the value of variables relating to inflammation and nutrition as a prognostic factors for mortality in an elderly community-dwelling population.

METHODS

We measured plasma levels of orosomucoid, C-reactive protein (CRP), albumin, and transthyretin, and the body mass index (BMI) of 245 subjects aged 65 to 95 living in the community (PAQUID study). The risk of death was analyzed two, four and six years after blood sampling by use of the Cox proportional hazards model with delayed entry. A survival curve was generated by the Kaplan-Meier method.

RESULTS

Multivariate analysis--including sex, BMI, and plasma levels of albumin, transthyretin orosomucoid and CRP levels--showed that orosomucoid in the highest quartile (>0.88 g/L) was the strongest predictor of mortality two years after blood sampling [relative risk (RR)=7.4; 95% interval confidence (IC) 2.2-24.6; P<0.1]; the association remained significant four and six years after blood sampling [RR=2.5; 95%IC 1.2-5.2 and RR=1.9; 95%IC 1.0-3.4 respectively, P<0.05]. Orosomucoid levels above 1 g/L (the most accurate threshold for prediction of mortality) were associated with a strong increase in the risk of death two years [RR=12.3; 95%IC 4.3-35.0; P<0.001], four years [RR=6.9; 95%IC 3.3-14.7; P<0.001], and six years [RR=4.4; 95%IC 2.3-8.5; P<0.001) after blood sampling.

CONCLUSION

These results further underline the association between systemic inflammation and mortality. They may help us to identify of high-risk subpopulations of elderly subjects so we can employ prevention strategies.

Immune and neurohormonal pathways in chronic heart failure

Chronic heart failure is a complex disorder with interactions among the cardiovascular, immune, and neurohormonal systems. The concept that the progression of heart failure is due to neurohormonal abnormalities has received the greatest attention to date, leading to substantial therapeutic benefits. Although many current therapies are also thought to exert a variety of immunologic effects, this has been much less studied. In this review, the authors discuss a number of interactions among immune pathways and neurohormonal abnormalities relevant to heart failure. Cytokines, in particular tumor necrosis factor-alpha, have tremendous interactive opportunities within a regulatory network of energy metabolism, immune function, and neuroendocrine and hormonal function. Inflammatory cytokines are known to contribute to the progression of heart failure, and have been related to patients' prognosis. Advanced heart failure can be considered a state of chronic (low-grade) inflammation, and there are many reasons to suggest that anticytokine therapy could be successful in these patients. These novel approaches are certainly not without some risk, and many of them are very expensive, which may limit their application to certain subgroups of patients. In the future, it may not be enough to monitor cardiac function alone. Rather, the immune and neurohormonal status of patients may also need to be included in the performance of a complete assessment.

The underreporting of results and possible mechanisms of 'negative' drug trials in patients with chronic heart failure

Large drug trials have become very important to determine which drugs should be used in the treatment of patients with chronic heart failure (CHF). When these trials showed "positive" results, publication of the data soon followed, leading to a substantial impact on prescription patterns. In the case of "negative" results, many times they were not published, or were reported as an abstract or as short paper disclosing only the main findings. In this article we will discuss some of these trials that were conducted in the last 10 years, since we believe they may provide insight into the pathophysiology and treatment options in CHF.

Vesnarinone suppresses TNF-induced activation of NF-kappa B, c-Jun kinase, and apoptosis

Vesnarinone, a synthetic quinolinone derivative used in the treatment of cardiac failure, exhibits immunomodulatory, anti-inflammatory, and cell growth regulatory properties. The mechanisms underlying these properties are not understood, but due to the critical role of nuclear transcription factor NF-kappa B in these responses, we hypothesized that vesnarinone must modulate NF-kappa B activation. We investigated the effect of vesnarinone on NF-kappa B activation induced by inflammatory agents. Vesnarinone blocked TNF-induced activation of NF-kappa B in a concentration- and time-dependent manner. This effect was mediated through inhibition of phosphorylation and degradation of I kappa B alpha, an inhibitor of NF-kappa B. The effects of vesnarinone were not cell type specific, as it blocked TNF-induced NF-kappa B activation in a variety of cells. NF-kappa B-dependent reporter gene transcription activated by TNF was also suppressed by vesnarinone. The TNF-induced NF-kappa B activation cascade involving TNF receptor 1-TNF receptor associated death domain-TNF receptor associated factor 2 NF-kappa B-inducing kinase-IKK was interrupted at the TNF receptor associated factor 2 and NF-kappa B-inducing kinase sites by vesnarinone, thus suppressing NF-kappa B reporter gene expression. Vesnarinone also blocked NF-kappa B activation induced by several other inflammatory agents, inhibited the TNF-induced activation of transcription factor AP-1, and suppressed the TNF-induced activation of c-Jun N-terminal kinase and mitogen-activated protein kinase kinase. TNF-induced cytotoxicity, caspase activation, and lipid peroxidation were also abolished by vesnarinone. Overall, our results indicate that vesnarinone inhibits activation of NF-kappa B and AP-1 and their associated kinases. This may provide a molecular basis for vesnarinone's ability to suppress inflammation, immunomodulation, and growth regulation.

Insights into pathogenesis and treatment of cytokines in cardiomyopathy

Our understanding of the pathophysiology of chronic heart failure is rapidly expanding. recent investigations suggest a role for various proinflammatory and vasoconstrictive cytokines in the development and progression of the disease. In particular, tumor necrosis factor-alpha, interlukin-6, and endothelin have all been implicated in heart failure desease progression. These cytokines appear to be activated in response to a remodeling, induction of programmed cell death, neurohormonal activation, and hemodynamics, these agents cause a variety of deleterious effects in the setting of ventricular dysfunction. Investigational inhibitors and antagonists of these substances show promise for the future treatment of heart failure.

The role of inflammatory mediators in chronic heart failure: cytokines, nitric oxide, and endothelin-1

There is now considerable evidence to suggest that neurohormonal and immune mechanisms may play a central role in the pathogenesis of chronic heart failure (CHF), which is likely to have important implications for the management of this condition. It has been proposed that CHF is a state of immune activation with inflammatory cytokines contributing to both the central and the peripheral manifestations of this syndrome. The immune system is the body's natural defence mechanism against infection and other stresses, which has several different components that interact with each other in a complex manner. The main components which are thought to be relevant to the pathogenesis of CHF are: cytokines, adhesion molecules, autoantibodies, nitric oxide, and endothelin-1, and this review will concentrate on these factors. This article will also discuss the potential role of anti-cytokine therapies in the treatment of CHF.

Serum IL-6 level and the development of disability in older persons

BACKGROUND

The serum concentration of interleukin 6 (IL-6), a cytokine that plays a central role in inflammation, increases with age. Because inflammation is a component of many age-associated chronic diseases, which often cause disability, high circulating levels of IL-6 may contribute to functional decline in old age. We tested the hypothesis that high levels of IL-6 predict future disability in older persons who are not disabled.

METHODS

Participants at the sixth annual follow-up of the Iowa site of the Established Populations for Epidemiologic Studies of the Elderly aged 71 years or older were considered eligible for this study if they had no disability in regard to mobility or in selected activities of daily living (ADL), and they were re-interviewed 4 years later. Incident cases of mobility-disability and of ADL-disability were identified based on responses at the follow-up interview. Measures of IL-6 were obtained from specimens collected at baseline from the 283 participants who developed any disability and from 350 participants selected randomly (46.9%) from those who continued to be non-disabled.

FINDINGS

Participants in the highest IL-6 tertile were 1.76 (95% CI, 1.17-2.64) times more likely to develop at least mobility-disability and 1.62 (95% CI, 1.02-2.60) times more likely to develop mobility plus ADL-disability compared with to the lowest IL-6 tertile. The strength of this association was almost unchanged after adjusting for multiple confounders. The increased risk of mobility-disability over the full spectrum of IL-6 concentration was nonlinear, with the risk rising rapidly beyond plasma levels of 2.5 pg/mL.

INTERPRETATION

Higher circulating levels of IL-6 predict disability onset in older persons. This may be attributable to a direct effect of IL-6 on muscle atrophy and/or to the pathophysiologic role played by IL-6 in specific diseases.

The changes of circulating tumor necrosis factor levels in patients with congestive heart failure influenced by therapy

Recent studies suggest that tumor necrosis factor-alpha (TNF-alpha) plays an important role in the pathogenesis of congestive heart failure and that drugs used in the treatment of heart failure have modulation effects on the production of TNF-alpha. To examine an alteration of circulating TNF-alpha concentration in patients with severe chronic heart failure after improving heart function and investigate the influence of agents on circulating TNF-alpha concentrations, we measured the plasma levels of TNF-alpha by enzyme linked immunoabsorbent assay in 31 patients and evaluated their heart functions before and after 72 h of therapy. The results showed that circulating TNF-alpha concentrations significantly decreased after therapy (from 124.36+/-14.85 pg/ml to 93.84+/-13.57 pg/ml, P<0.001). The circulating TNF-alpha concentrations of patients (n = 22) whose heart function was improved one class or more after therapy declined significantly (from 127.51+/-20.78 pg/ml to 91.54+/-18.56 pg/ml, P<0.01) but this situation did not exist in patients (n = 9) whose heart functions had no or little improvement. All patients were divided into three groups according to their management: 'group A' (n = 14) who received milrinone and angiotensin-converting enzyme inhibitors (ACEI), 'group B' (n = 6) who received milrinone but not ACEI and 'group C' (n = 11) who received ACEI and dobutamine but not milrinone. The circulating TNF-alpha concentration of patients in group A significantly declined (from 126.68+/-26.04 pg/ml to 95.92+/-24.79 pg/ml, P<0.01). No statistical significance of change of TNF-alpha concentration was found in patients in group B or group C, although a tendency of decline existed (from 119.92+/-34.72 pg/ml to 84.33+/-30.70 pg/ml and from 123.83+/-19.50 pg/ml to 96.37+/-16.62 pg/ml, respectively). These findings support that decreased plasma TNF-alpha level accompanies the improvement of heart function. This phenomenon may be explained by the special abilities of agents, such as ACEI and milrinone, to inhibit the TNF-alpha production.

Innovative drug treatments for viral and autoimmune myocarditis

Myocarditis has been shown to be a common cause of cardiomyopathy and is believed to account for 25% of all cases in human beings. Unfortunately, the disease is difficult to detect before a myopathic process ensues. Treatment of myocarditis-induced heart failure includes the standard regimen of diuretics, digoxin, angiotensin-converting enzyme inhibitors, and currently, beta-adrenergic blockers. Treatment of myocarditis itself is dependent on the etiology of the illness. Treatments under investigation include immunosuppressants, nonsteroidal antiinflammatory agents, immunoglobulins, immunomodulation, antiadrenergics, calcium-channel blockers, angiotensin-converting enzyme inhibitors, nitric oxide inhibition (e.g., aminoguanidine), and antiviral agents. Despite advances in treatment, more work needs to be done in the early detection of myocarditis. Additionally, better means need to be established for distinguishing between viral and autoimmune forms of the disease, so that appropriate treatment can be instituted.