TNF-alpha as a promising therapeutic target in chronic asthma: a lesson from rheumatoid arthritis

Infliximab alleviates inflammation and ex vivo airway hyperreactivity in asthmatic E3 rats

Tumor necrosis factor-α (TNF-α) has been implicated in the pathogenesis of asthma, and neutralization of TNF-α is an effective therapy for inflammatory diseases. The present study tested the idea that a TNF-α antibody, infliximab, may be useful in the management of asthma. E3 rats were immunized with ovalbumin (OVA)/alum and received infliximab intra-peritoneally. Two weeks later, OVA-PBS was instilled intranasally daily for 7 days. Bronchoalveolar lavage fluids (BALFs), serum and lung homogenates were collected for analysis of cells and inflammatory mediators. Contractile responses of lobar-bronchus segments to agonists were functionally tested. Pulmonary tissues were investigated using histological examination. The results showed that the sensitized 'model E3 rats' exhibited an increase in the total amount of inflammatory cells, primarily eosinophils, in BALF and pulmonary tissue, as well as epithelial damage. Serum levels of IgE increased and so did the levels of nitric oxide, inducible nitric oxide synthase, TNF-α and IL-4, IL-5 and IL-13 in lung homogenate and serum. Furthermore, the contractile responses in bronchi induced by endothelin-1, sarafotoxin 6c and bradykinin increased and isoprenaline-induced relaxations decreased. All these changes induced by the sensitization procedure were reduced by the infliximab treatment. The results suggest that infliximab prevents the development of local airway inflammation and antagonizes changes of the bronchial smooth muscle receptor phenotype, thereby blocking the development of airway smooth muscle hyperreactivity of asthmatic rats.

Cytokine gene polymorphism and asthma susceptibility, progress and control level

Asthma is a multifactor inflammatory disorder, and its management requires understanding of its various pathogenesis and control mechanisms. Cytokines and other inflammatory mediators are important factors in asthma pathophysiology. In this study, we evaluated the role of cytokine polymorphisms in the asthma susceptibility, progress, control, and lung functions. IL-4-C590T polymorphism by PCR-RFLP method, IFN-γ T+874A, TNF-α-A308G, IL-6 G-174C and TGF-β T+869C variants by ARMS-PCR method and IgE serum level by ELISA technique were determined in 81 asthmatic patients and 124 normal subjects. Asthma diagnosis, treatment and control levels were considered using standard schemes and criteria. TNF-α-308GA genotype was more frequent in asthmatics (P = 0.025, OR 3.352), and polymorphisms between different asthma control levels (P > 0.05) were not different. IFN-γ+874AT genotype had a positive correlation with the familial history of asthma (P = 0.034, OR 2.688). IL-6-174C allele (P = 0.045), TNF-α-308GG genotype (P = 0.002) and TNF-α-308G allele (P = 0.004) showed reduced values, and TNF-α-308GA genotype (P = 0.002) increased FEF25-75 value in asthmatics. IFN-γ+874AA genotype caused a decrease in FVC factor (P = 0.045). This study showed that TNF-α-308GA is a risk factor for asthma, but cytokine gene variants do not affect asthma control and IgE serum levels. Variants producing lower levels of IL-6, TNF-α and IFN-γ are associated with reduced pulmonary capacities. To achieve an appropriate schema for asthma management, further studies with consideration of different aspects in a larger group of patients would be more elucidative.

Does airway smooth muscle express an inflammatory phenotype in asthma?

In addition to hyperresponsiveness in asthma, airway smooth muscle (ASM) also manifests an inflammatory phenotype characterized by augmented expression of mediators that enhance inflammation, contribute to tissue remodelling and augment leucocyte trafficking and activity. Our present review summarizes contemporary understanding of ASM-derived mediators and their paracrine and autocrine actions in airway diseases.

Certolizumab pegol (CDP870) for rheumatoid arthritis in adults

BACKGROUND

TNF-alpha inhibitors have been shown to reduce the risk of joint damage and improve physical function and quality of life in people with rheumatoid arthritis (RA). This is the first Cochrane review of certolizumab pegol, a new TNF-alpha inhibitor.

OBJECTIVES

To assess the effectiveness and safety of certolizumab pegol (CDP870) in patients with RA who have not responded well to conventional disease modifying anti-rheumatic drugs (DMARDs).

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2009, Issue 3),  MEDLINE (1966 to November 2009), EMBASE (1966 to November 2009), Scopus (January 2004 to November 2009), TOXLINE (until November 2009), Web of Knowledge (until November 2009); websites of the US Food and Drug Administration (FDA) and European Medicines Evaluation Agency (EMEA) (until November 2009), and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials that compared certolizumab pegol with any other agent including placebo or methotrexate (MTX) in adult RA patients with active rheumatoid arthritis despite current or prior treatment with conventional DMARDs, such as methotrexate (MTX).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results, trial quality and extracted data.

MAIN RESULTS

Five trials were included. We included in the analysis 2394 people for effectiveness and 2094 people for safety. The duration of follow-up was from 12 to 52 weeks, and the range of doses of certolizumab pegol were from 50 to 400 mg subcutaneously (sc). In three trials the control was placebo plus methotrexate (MTX) and in two trials it was just placebo. Significant improvements were observed at 24 weeks with the approved dose of 200 mg certolizumab pegol: American College of Rheumatology (ACR) 50% improvement: risk ratio (RR) 6.01 (95% CI 3.84 to 9.40) with an absolute benefit of 29% (95% CI 25% to 34%), number needed to treat to benefit (NNTB) of 4 (3 to 5) and the Health Assessment Questionnaire (HAQ) mean difference (MD) - 0.39 (95% CI -0.45 to -0.32) (scale 0 to 3). At 52 weeks the results were quite similar: ACR 50% improvement RR 5.27 (95% CI 3.19 to 8.71), HAQ mean difference (MD) - 0.42 (95% CI -0.52 to -0.32). Serious adverse events were more frequent for certolizumab pegol 200 mg, Peto OR 2.02 (95% CI 1.24 to 3.30). The most common adverse events with certolizumab pegol 200 mg were: upper respiratory tract infections, Peto OR 2.21 (95% CI 1.15 to 4.25); hypertension, Peto OR 2.81 (95% CI 1.38 to 5.75); and nasopharyngitis, Peto OR 2.71 (95% CI 1.30 to 5.66).

AUTHORS' CONCLUSIONS

With an overall high grade of evidence this review revealed an improvement of clinical results (ACR50, 28 joint disease activity score (DAS-28) remission and HAQ scores) with certolizumab pegol. Adverse events were more frequent with certolizumab; there was a statistically significant increase in the number of serious adverse events, infections and hypertension.

Anti-inflammatory effects of the neurotransmitter agonist Honokiol in a mouse model of allergic asthma

Chronic airway inflammation is a hallmark of asthma, an immune-based disease with great societal impact. Honokiol (HNK), a phenolic neurotransmitter receptor (γ-aminobutyric acid type A) agonist purified from magnolia, has anti-inflammatory properties, including stabilization of inflammation in experimentally induced arthritis. The present study tested the prediction that HNK could inhibit the chronic inflammatory component of allergic asthma. C57BL/6 mice sensitized to and challenged with OVA had increased airway hyperresponsiveness to methacholine challenge and eosinophilia compared with naive controls. HNK-treated mice showed a reduction in airway hyperresponsiveness as well as a significant decrease in lung eosinophilia. Histopathology studies revealed a marked drop in lung inflammation, goblet cell hyperplasia, and collagen deposition with HNK treatment. Ag recall responses from HNK-treated mice showed decreased proinflammatory cytokines in response to OVA, including TNF-α-, IL-6-, Th1-, and Th17-type cytokines, despite an increase in Th2-type cytokines. Regulatory cytokines IL-10 and TGF-β were also increased. Assessment of lung homogenates revealed a similar pattern of cytokines, with a noted increase in the number of FoxP3(+) cells in the lung. HNK was able to alter B and T lymphocyte cytokine secretion in a γ-aminobutyric acid type A-dependent manner. These results indicate that symptoms and pathology of asthma can be alleviated even in the presence of increased Th2 cytokines and that neurotransmitter agonists such as HNK have promise as a novel class of anti-inflammatory agents in the treatment of chronic asthma.

Role of muscarinic receptor activation in regulating immune cell activity in nasal mucosa

BACKGROUND

The prevalence of airway inflammatory disorders keeps rising; its pathogenic mechanism is still not fully understood.

OBJECTIVE

The present study aimed to investigate the role of muscarinic receptor (M receptor) in regulating the immune cell activity in nasal mucosa by using surgical removed nasal mucosa from patients with nasal polyposis (NP) as a study platform.

METHODS

Human nasal mucosal sample was collected from inferior turbinectomy of 86 patients with NP or/and allergic rhinitis. Expression of tumor necrosis factor alpha (TNF-alpha), M receptor, OX40 ligand was measured in nasal mucosa by enzyme-linked immunosorbent assay, flow cytometry, and Western blotting assay.

RESULTS

When compared with non-NP (nNP) nasal mucosa, contents of TNF-alpha and TNF-alpha+ cells markedly increased in NP nasal mucosa; immune staining colocalized M3 receptor+ and TNF-alpha+ cells in NP nasal mucosa; exposure of isolated CD4+ T cells to methacholine induced the release of TNF-alpha. We also found CD11c+/M3 receptor+ cells in NP nasal mucosa. Methacholine increased the expression of OX40L in dendritic cells. Staphylococcal (S) aureus and S. enterotoxin B (SEB) were detected in NP nasal mucosa. Exposure of dendritic cells or naïve CD4+ T cells to SEB initiated the expression of M3 receptor at mRNA and protein levels.

CONCLUSIONS

The present data demonstrate that parasympathetic activity has the capacity to activate dendritic cells to release OX40 ligand, the latter induces CD4+ T cells to produce IL-4 and TNF-alpha that may further contribute to the pathogenesis of NP.

Tumor necrosis factor-alpha in severe corticosteroid-refractory asthma

Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine. Blocking TNF-alpha has been demonstrated to be effective in various diseases, including both rheumatoid and psoriatic arthritis. There is evidence to show that levels of TNF-alpha are elevated in patients with severe asthma. TNF-alpha is involved in the initiation and perpetuation of the inflammatory process, epithelial damage and remodeling, and mucin hypersecretion. Furthermore, TNF-alpha polymorphism has also been reported in the asthmatic population. Based on the necessity for alternative treatments for asthmatics with severe disease and those who are particularly resistant to conventional asthma therapy, it has been shown that molecules targeted at blocking the effects of TNF-alpha probably constitute a considerable advance in the management of these difficult patients. This review focuses on the evidence of TNF-alpha axis upregulation in severe corticosteroid-refractory asthma, as well as the role of TNF-alpha inhibition and the adverse effects of treatment.

Protective effects of quercetin on liver injury induced by ethanol

Quercetin, a natural compound of multiple origins, has broad biopharmacological effects, such as antioxidant, directly scavenging free radical, and hepatoprotectivity effects. This study is designed to investigate the interveneous effect of quercetin on liver injury induced by ethanol in rats. The rats that were orally treated with 50% ethanol for continuous ten days, which resulted in cell necrosis, fibrosis and inflammatory infiltration, were included in this study. Higher contents of AST, ALT ADH, γ-GT, TG in plasma and MDA in liver tissue, and lower content of GSH in liver tissue were highlighted in ethanol-treated rats when compared with healthy ones. The levels of cytokines such as IL-1β, IL-1, IL-6, IL-8, and TNF-α in rats plasma were also significantly enhanced, and level of IL-10 was obviously lowered through ethanol treatment. By preventive and synchronism treatment with quercetin for fourteen days, the contents of AST, ALT ADH, γ-GT, TG and MDA, and levels of IL-1β, IL-1, IL-6, IL-8, and TNF-α were significantly reduced, whereas GSH and level of IL-10 were obviously increased. It may be deduced that quercetin, by multiple mechanisms interplay, demonstrated somewhat protective effect on liver injury induced by ethanol in rats.

Therapeutic targets for new therapy for corticosteroid refractory asthma

BACKGROUND

Corticosteroids are the most potent anti-inflammatory agents for the treatment of mild to moderate asthma. However, a small percentage of the asthma population (< 10%) do not respond well, or at all, to corticosteroid therapy, and this severe corticosteroid-refractory asthma contributes to more than 50% of health care expenditure for all asthma because these is no appropriate pharmacological therapy.

METHODS

If the molecular mechanism of corticosteroid insensitivity is uncovered, it may in turn provide insights into the key mechanism of corticosteroid action and rational implementation of treatment regimens that restore corticosteroid sensitivity or replace corticosteroid therapy. This review focuses on why severe asthma patients are corticosteroid-insensitive, and discusses present and future therapeutic and preventative strategies for corticosteroid-refractory asthma.

CONCLUSIONS

Corticosteroid-refractory asthma is a heterogeneous disease and can be controlled by add-on treatment of corticosteroid-sparing agents or effective new drugs based on individual abnormalities. The elucidation of the cause of the relative lack of corticosteroid response in this subgroup of asthmatic individuals may have important implications for other diseases.

Pre-exposure to Staphylococcal enterotoxin A exacerbates the pulmonary allergic eosinophil recruitment in rats

Gram-positive Staphylococcus aureus releases classical enterotoxins which aggravates allergic airway diseases. However, little is known about the mechanisms underlying the cell influx exacerbation in asthmatic individuals under exposure to Staphylococcal enterotoxins. We therefore aimed to investigate the effects of airways exposure to Staphylococcal enterotoxin A (SEA) to pulmonary leukocyte recruitment in rats sensitized and challenged with ovalbumin (OVA). Rats were exposed to SEA at 4h prior to OVA challenge or at 4h post-OVA challenge. Bronchoalveolar lavage (BAL) fluid, bone marrow and lung tissue were obtained at 24h after OVA challenge. Pre-exposure to SEA markedly enhanced the eosinophil counts in both BAL fluid and pulmonary tissue in OVA-challenged rats, whereas neutrophil and mononuclear cell counts remained unchanged. In bone marrow, pre-exposure to SEA alone significantly increased the number of eosinophils, and that was further increased in OVA-challenged rats. Exposure to SEA post-OVA challenge did not affect the number of eosinophils, neutrophils and mononuclear cells in BAL fluid. Pre-exposure to the endotoxin lipopolyssacharide (LPS) in OVA-challenged animals rather enhanced the neutrophil number in BAL fluid. In rats pre-exposed to SEA and OVA-challenged, a marked elevation in the levels of TNF-alpha and eotaxin (but not of IL-10) in BAL fluid was observed. The eotaxin levels increased by about of 3-fold in alveolar macrophages treated with SEA in vitro. In conclusion, airways pre-exposure to SEA causes a selective increase in eosinophil number in BAL fluid and bone marrow of OVA-challenged rats by mechanisms involving enhancement of TNF-alpha and eotaxin synthesis.

Immunopathogenesis of bronchial asthma

Bronchial asthma is a common immune-mediated disorder characterized by reversible airway inflammation, mucus production, and variable airflow obstruction with airway hyperresponsiveness. Allergen exposure results in the activation of numerous cells of the immune system, of which dendritic cells (DCs) and Th2 lymphocytes are of paramount importance. Although the epithelium was initially considered to function solely as a physical barrier, it is now evident that it plays a central role in the Th2-cell sensitization process due to its ability to activate DCs. Cytokines are inevitable factors in driving immune responses. To the list of numerous cytokines already known to be involved in the regulation of allergic reactions, new cytokines were added, such as TSLP, IL-25, and IL-33. IgE is also a central player in the allergic response. The activity of IgE is associated with a network of proteins, especially with its high- and low-affinity Fc receptors. Understanding the cellular and molecular mechanisms of allergic reactions helps us not only to understand the mechanisms of current treatments, but is also important for the identification of new targets for biological intervention. An IgE-specific monoclonal antibody, omalizumab, has already reached the clinic and similar biological agents will surely follow.

Managing patients with chronic severe asthma: rise to the challenge

Most asthmatic patients with moderate to severe disease can be satisfactorily managed with a combination of inhaled corticosteroids and beta(2)-agonists. However, there are perhaps 10% of the asthmatic population with persistent symptoms, impaired quality of life and excessive health-care utilization, despite this management regime. These patients often require frequent and even occasionally regular oral corticosteroid use. Chronic, severe asthma is a heterogeneous disease with distinct sub-phenotypes. A systematic diagnostic work-up may help to identify these distinct sub-phenotypes and this may help guide treatment and may even provide information about prognosis. Optimal treatment of chronic severe asthma should achieve the best possible asthma control and quality of life with the least dose of systemic corticosteroids. The choice and formulation of therapeutic agent is dictated by the severity of disease and includes conventional, immunosuppressive/immunomodulating and biologic therapies. Unfortunately, current asthma management guidelines offer little contribution to the care of the challenging patient with chronic severe asthma. This review article aims at summarizing the evidence regarding various therapeutic modalities for chronic severe asthma and also aims to provide a practical approach to diagnosis and management for the benefit of those who have a specific interest in this problematic condition.

Advances in therapy for adult asthma

There are >22 million Americans with asthma. Chronic asthma is a worldwide problem with an increasing socioeconomic burden on individuals and on society. Recent advances have been made in diagnostic lung imaging, defining control of asthma, as well as in the education of patients with asthma. Accurate diagnosis of the cause of chronic cough in adults and of asthma in elderly individuals will help affected individuals receive appropriate treatment. Inhaled corticosteroids are the recommended first-line therapy for persistent asthma and can help prevent exacerbations in patients with asthma that are not well controlled. Early intervention and improved management can significantly reduce the socioeconomic burden of asthma. Patient education is an essential part of asthma management.

A novel hybrid aspirin-NO-releasing compound inhibits TNFalpha release from LPS-activated human monocytes and macrophages

Background

The cytoprotective nature of nitric oxide (NO) led to development of NO-aspirins in the hope of overcoming the gastric side-effects of aspirin. However, the NO moiety gives these hybrids potential for actions further to their aspirin-mediated anti-platelet and anti-inflammatory effects. Having previously shown that novel NO-aspirin hybrids containing a furoxan NO-releasing group have potent anti-platelet effects, here we investigate their anti-inflammatory properties. Here we examine their effects upon TNFα release from lipopolysaccharide (LPS)-stimulated human monocytes and monocyte-derived macrophages and investigate a potential mechanism of action through effects on LPS-stimulated nuclear factor-kappa B (NF-κB) activation.

Methods

Peripheral venous blood was drawn from the antecubital fossa of human volunteers. Mononuclear cells were isolated and cultured. The resultant differentiated macrophages were treated with pharmacologically relevant concentrations of either a furoxan-aspirin (B8, B7; 10 μM), their respective furazan NO-free counterparts (B16, B15; 10 μM), aspirin (10 μM), existing nitroaspirin (NCX4016; 10 μM), an NO donor (DEA/NO; 10 μM) or dexamethasone (1 μM), in the presence and absence of LPS (10 ng/ml; 4 h). Parallel experiments were conducted on undifferentiated fresh monocytes. Supernatants were assessed by specific ELISA for TNFα release and by lactate dehydrogenase (LDH) assay for cell necrosis. To assess NF-κB activation, the effects of the compounds on the loss of cytoplasmic inhibitor of NF-κB, IκBα (assessed by western blotting) and nuclear localisation (assessed by immunofluorescence) of the p65 subunit of NF-κB were determined.

Results

B8 significantly reduced TNFα release from LPS-treated macrophages to 36 ± 10% of the LPS control. B8 and B16 significantly inhibited monocyte TNFα release to 28 ± 5, and 49 ± 9% of control, respectively. The B8 effect was equivalent in magnitude to that of dexamethasone, but was not shared by 10 μM DEA/NO, B7, the furazans, aspirin or NCX4016. LDH assessment revealed none of the treatments caused significant cell lysis. LPS stimulated loss of cytoplasmic IκBα and nuclear translocation of the p65 NF-κB subunit was inhibited by the active NO-furoxans.

Conclusion

Here we show that furoxan-aspirin, B8, significantly reduces TNFα release from both monocytes and macrophages and suggest that inhibition of NF-κB activation is a likely mechanism for the effect. This anti-inflammatory action highlights a further therapeutic potential of drugs of this class.

TPL2-mediated activation of ERK1 and ERK2 regulates the processing of pre-TNF alpha in LPS-stimulated macrophages

Activation of the TPL2-MKK1/2-ERK1/2 signalling pathway is essential for lipopolysaccharide (LPS)-stimulated production of TNF alpha in macrophages. Here, we demonstrate that, unexpectedly, TPL2-deficient or MKK1-inhibited macrophages produce near normal levels of pre-TNF alpha when TLR2, TLR4 and TLR6 are activated by their respective agonists, but fail to secrete TNFalpha. We show that LPS stimulates the appearance of pre-TNFalpha at the cell surface and that this is prevented by inhibition of MAPK kinases 1 and 2 (MKK1/2) or in TPL2-deficient macrophages. However, the transport of pre-TNF alpha from the Golgi to the plasma membrane is unaffected by inhibition of the TPL2-MKK1/2-ERK1/2 pathway. Finally, we show that TACE, the protease that cleaves pre-TNF alpha to secreted TNFalpha, is phosphorylated by ERK1 and ERK2 (ERK1/2) at Thr735 in LPS-stimulated macrophages. Therefore, although TACE activity per se is not required for the LPS-stimulated cell surface expression of pre-TNF alpha, the phosphorylation of this protease might contribute to, or be required for, the cell surface expression of the pre-TNF alpha-TACE complex.

Gene response of human monocytic cells for the detection of antimigraine activity of feverfew extracts

The herb feverfew is a folk remedy for various conditions, including inflammation, fever, psoriasis, rheumatism, and asthma. Like many herbal medicines, feverfew's mechanisms of action in the human body are largely unknown and its active ingredients remain elusive. Very often, different extraction methods of herb material produce different physical and biochemical properties and variation in clinical efficacy. We identified 3 major methods of extraction for feverfew aerial parts and used microarray technology to test the hypothesis that extracts produced by different methods elicit different gene expression profiles. We have identified approximately 200 genes that are consistently regulated by the 2 presumptive active antimigraine feverfew extracts but not associated with the inactive extract. Our results suggest that the presumptive active feverfew extracts potently stimulate more genes in human cells than the inactive extracts. We also identified several genes as unique signatures for these active extracts. All 3 feverfew extracts exhibited similar blockades on lipopolysaccharide-mediated TNF-alpha (tumor necrosis factor alpha) release, implicating that TNF-alpha is not responsible for the differences in the effects of the 3 feverfew extracts in human cells. In contrast, the active extracts more effectively suppressed CCL2 (also known as monocyte chemoattractant protein 1, MCP-1) than the inactive extracts, suggesting that CCL2 is a potential cellular target for feverfew's antimigraine effects.

Tumor necrosis factor-alpha: a promising therapeutic target for asthma?

Asthma is a disease that encompasses a variety of features including airway smooth muscle abnormalities, airway inflammation, and structural changes in the airway. Historically, it has been classified depending on the severity of the disease, the frequency of symptoms, and the level of treatment required to control them. Severe or refractory asthma accounts for approximately 10% of the patient population with asthma and for about 30% of the healthcare costs of this disease. It is often associated with conditions that might lead to activation of innate immunity in the lung, and it has been suggested that some of the features of severe asthma might be due to upregulation of the tumor necrosis factor-alpha (TNFalpha) pathway. In support of this, studies have shown that severe asthma is associated with an increased presence of TNFalpha within the airway and an increase in TNFalpha expression on peripheral blood mononuclear cells. Moreover, TNFalpha has the ability to induce several of the pro-inflammatory changes associated with severe asthma. Interest in the role of TNFalpha in severe asthma has increased following reports that antagonism with etanercept or infliximab is associated with improvement in asthma control in patients with severe asthma. In this article, we discuss the biology, function, and clinical effects of TNFalpha with particular reference to severe asthma.

Universal risk factors for multifactorial diseases: LifeLines: a three-generation population-based study

The risk for multifactorial diseases is determined by risk factors that frequently apply across disorders (universal risk factors). To investigate unresolved issues on etiology of and individual's susceptibility to multifactorial diseases, research focus should shift from single determinant-outcome relations to effect modification of universal risk factors. We present a model to investigate universal risk factors of multifactorial diseases, based on a single risk factor, a single outcome measure, and several effect modifiers. Outcome measures can be disease overriding, such as clustering of disease, frailty and quality of life. "Life course epidemiology" can be considered as a specific application of the proposed model, since risk factors and effect modifiers of multifactorial diseases typically have a chronic aspect. Risk factors are categorized into genetic, environmental, or complex factors, the latter resulting from interactions between (multiple) genetic and environmental factors (an example of a complex factor is overweight). The proposed research model of multifactorial diseases assumes that determinant-outcome relations differ between individuals because of modifiers, which can be divided into three categories. First, risk-factor modifiers that determine the effect of the determinant (such as factors that modify gene-expression in case of a genetic determinant). Second, outcome modifiers that determine the expression of the studied outcome (such as medication use). Third, generic modifiers that determine the susceptibility for multifactorial diseases (such as age). A study to assess disease risk during life requires phenotype and outcome measurements in multiple generations with a long-term follow up. Multiple generations will also enable to separate genetic and environmental factors. Traditionally, representative individuals (probands) and their first-degree relatives have been included in this type of research. We put forward that a three-generation design is the optimal approach to investigate multifactorial diseases. This design has statistical advantages (precision, multiple-informants, separation of non-genetic and genetic familial transmission, direct haplotype assessment, quantify genetic effects), enables unique possibilities to study social characteristics (socioeconomic mobility, partner preferences, between-generation similarities), and offers practical benefits (efficiency, lower non-response). LifeLines is a study based on these concepts. It will be carried out in a representative sample of 165,000 participants from the northern provinces of the Netherlands. LifeLines will contribute to the understanding of how universal risk factors are modified to influence the individual susceptibility to multifactorial diseases, not only at one stage of life but cumulatively over time: the lifeline.

Allergen induced gene expression of airway epithelial cells shows a possible role for TNF-alpha

BACKGROUND

Epithelium is more than a physical barrier for pathogens and allergens, as it is also capable of producing mediators in response to these environmental factors. Some of these mediators have an immuno-modulatory function, suggesting that epithelium is an active component of the immune response. Here, we fully characterize the expression profile of airway epithelial cells in response to house dust mite (HDM) allergen.

METHODS

H292 cells were exposed to HDM extract for 24 h, RNA and supernatant was used for microarray analysis and multiplex enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTS

A total of 38,500 genes, 813 were differentially expressed by more than twofold and 116 even more than fivefold. Interestingly, among the most up-regulated genes, a large number are involved in cell-to-cell communication. These include chemokines (CCL-8 and -20, CXCL-1, -2 and -3), cytokines (IL-1alpha, -6 and -11), anti-inflammatory factors [PTX-3, interleukin (IL)-13Ralpha, tumour necrosis factor (TNF)-alphaIP3], and factors that are involved in repair of the mucosal tissue (LOXL-2, NID-2, HBEGF, MUC-5AC and MUC-5B). Pathway analysis showed that a number of these genes are transcriptionally regulated by TNF-alpha, which we could detect by quantitative polymerase chain reaction at earlier time points after HDM exposure. In addition, we could detect increased protein levels for TNF-alpha, IL-6, IL8, granulocyte-macrophage colony-stimulating factor, granulocyte colony stimulating factor and interferon (IFN)-gamma using ELISA.

CONCLUSION

Our data show that a broad range of mediators produced upon allergen exposure by these mediators' epithelial cells can participate in the immune response via recruitment and activation of cells of the immune system.

Pharmacotherapy of asthma

The pharmacotherapy of asthma is a complex and evolving topic. A detailed understanding of the pathophysiologic processes involved in the asthmatic response forms the basis for understanding the actions of drugs used to treat this condition. Likewise, a solid comprehension of the medicinal chemistry and pharmacologic properties of the numerous agents involved in the treatment of asthma is critical for rationalizing drug choices and understanding potential side effects. Asthma is addressed at several points in the PharmD curriculum at South University including in the Pathophysiology (quarter 2), Integrated Sequence III (quarter 6), and Critical Care (quarter 9) courses. Various teaching strategies are employed throughout, along with weekly case-based recitations. The content presented here includes a synopsis of the pathophysiology and pharmacology from our Integrated Sequence III block on inflammatory diseases and asthma. A short review of pertinent pathophysiology is followed by a detailed presentation on the various classes of asthma drugs which includes their chemistry, mechanism of action, pharmacokinetics, toxicity, and interactions. This presentation is designed to prepare students for asthma therapeutics, which follows next in the schedule. The complexities of asthma pharmacotherapy are stressed along with current controversies and future drug development.

Tumor necrosis factor inhibitors for the treatment of asthma

Asthma is a unique form of chronic airway inflammation characterized by reversible airway obstruction, airway hyperresponsiveness and the production of specific inflammatory mediators. Local activation of both immune and nonimmune cells in the lung triggers the release of these immunomodulator molecules. Among them, tumor necrosis factor (TNF)-alpha, a multipotent pro-inflammatory mediator, plays a critical role in immunoregulation of asthma by contributing to bronchopulmonary inflammation and airway hyperresponsiveness. Blocking TNF-alpha activity has already shown outstanding efficacy in other chronic inflammatory diseases including rheumatoid arthritis, Crohn's disease, and psoriasis. The successful treatment of these other chronic inflammatory diseases provides hope that TNF inhibitors may have application for the treatment of asthma. Recent developments in animal models and clinical trials in patients with severe asthma provide strong support for the concept that blocking TNF-alpha activity represents a new approach in asthma therapy. In this review, we address the multipotential role of TNF-alpha in asthma and the efficacy and safety of TNF-alpha blocking agents in asthma.

Regulation of Cellular Metabolism and Cytokines by the Medicinal Herb Feverfew in the Human Monocytic THP-1 Cells

The herb feverfew is a folk remedy for various symptoms including inflammation. Inflammation has recently been implicated in the genesis of many diseases including cancers, atherosclerosis and rheumatoid arthritis. The mechanisms of action of feverfew in the human body are largely unknown. To determine the cellular targets of feverfew extracts, we have utilized oligo microarrays to study the gene expression profiles elicited by feverfew extracts in human monocytic THP-1 cells. We have identified 400 genes that are consistently regulated by feverfew extracts. Most of the genes are involved in cellular metabolism. However, the genes undergoing the highest degree of change by feverfew treatment are involved in other pathways including chemokine function, water homeostasis and heme-mediated signaling. Our results also suggest that feverfew extracts effectively reduce Lipopolysaccharides (LPS)-mediated TNF-alpha and CCL2 (MCP-1) releases by THP-1 cells. We hypothesize that feverfew components mediate metabolism, cell migration and cytokine production in human monocytes/macrophages.

Increased expression of the macrophage markers and of 11beta-HSD-1 in subcutaneous adipose tissue, but not in cultured monocyte-derived macrophages, is associated with liver fat in human obesity

OBJECTIVE

To determine whether increased expression of macrophage markers and of inflammatory markers in subcutaneous adipose tissue is associated with liver fat in human obesity. We also determined whether expression of TNF (gene encoding TNF-alpha), HSD11B1 (gene encoding 11beta-HSD-1) and RETN (gene encoding resistin) in cultured monocyte-derived macrophages differs between obese/overweight and non-obese subjects.

DESIGN

Cross-sectional comparison of obese/overweight and non-obese subjects with respect to adipose tissue gene expression, gene expression in monocyte-derived macrophages, liver fat content and in vivo insulin sensitivity.

SUBJECTS

Adipose tissue gene expression, gene expression in monocyte-derived macrophages, liver fat content and in vivo insulin sensitivity: 10 healthy non-obese (24.2+/-1.0 kg/m(2)) and 10 healthy obese/overweight (33.1+/-1.7 kg/m(2)) women. Gene expression in monocyte-derived macrophages: seven healthy non-obese (22.1+/-0.7 kg/m(2)) and seven healthy obese/overweight (36.9+/-2.2 kg/m(2)) women.

MEASUREMENTS

Adipose tissue biopsies and blood samples for isolation of peripheral mononuclear cells were taken after an overnight fast. Liver fat content was measured using magnetic resonance proton spectroscopy. Whole body insulin sensitivity was measured using the hyperinsulinemic euglycemic clamp technique. Expression levels of TNF, HSD11B1, RETN and the macrophage markers CD68 and ITGAM were determined by real-time PCR.

RESULTS

In adipose tissue, expression of HSD11B1, ITGAM and CD68 was significantly increased in the obese/overweight as compared to the non-obese group. Expression of all these genes was closely positively correlated with liver fat content and inversely correlated with whole body insulin sensitivity. The associations between expression of CD68, ITGAM and HSD11B1 and liver fat were independent of obesity. There were no differences in TNF, HSD11B1, RETN or CD68 gene expression basally or after stimulation with lipopolysaccharide in monocyte-derived macrophages between obese/overweight and non-obese subjects.

CONCLUSION

Accumulation of fat in the liver is associated with increased adipose tissue inflammation independent of obesity.

Steroid-resistant sarcoidosis: is antagonism of TNF-alpha the answer?

Steroid-resistant sarcoidosis has conventionally been treated with various drugs, including methotrexate, azathioprine, cyclophosphamide, cyclosporine, antimalarial drugs and thalidomide, with variable success. There is a compelling need for more efficient and safer alternatives to these agents. Several lines of evidence suggest a critical role of TNF-alpha (tumour necrosis factor-alpha) in the initiation and organization of sarcoid granulomas. Inhibition of TNF-alpha with monoclonal antibodies has therefore received attention as a potential treatment option in therapy-resistant sarcoidosis. A number of case reports and small case series describe successful treatment of refractory disease with infliximab. Preliminary evidence from an RCT (randomized controlled trial) with infliximab in pulmonary sarcoidosis suggests a modest improvement in functional and radiological parameters. In contrast, the results with etanercept have been disappointing, perhaps related to differences in the mechanism of TNF-alpha blockade. The experience with adalimumab in sarcoidosis is too limited to draw conclusions. An open-label study and an RCT evaluating the efficacy of adalimumab in sarcoidosis with pulmonary and cutaneous involvement respectively, have been initiated. Although TNF-alpha antagonists appear relatively safe, especially when compared with conventional agents, caution is warranted in view of the increased incidence of tuberculosis, which may be a particular diagnostic challenge in patients with sarcoidosis. Pending publication of the RCTs, the use of TNF-alpha blockade in sarcoidosis should remain in the realm of experimental treatment.

p38 MAP-kinases pathway regulation, function and role in human diseases

Mammalian p38 mitogen-activated protein kinases (MAPKs) are activated by a wide range of cellular stresses as well as in response to inflammatory cytokines. There are four members of the p38MAPK family (p38alpha, p38beta, p38gamma and p38delta) which are about 60% identical in their amino acid sequence but differ in their expression patterns, substrate specificities and sensitivities to chemical inhibitors such as SB203580. A large body of evidences indicates that p38MAPK activity is critical for normal immune and inflammatory response. The p38MAPK pathway is a key regulator of pro-inflammatory cytokines biosynthesis at the transcriptional and translational levels, which makes different components of this pathway potential targets for the treatment of autoimmune and inflammatory diseases. However, recent studies have shed light on the broad effect of p38MAPK activation in the control of many other aspects of the physiology of the cell, such as control of cell cycle or cytoskeleton remodelling. Here we focus on these emergent roles of p38MAPKs and their implication in different pathologies.

Therapeutic effects of nitric oxide-aspirin hybrid drugs

This review examines the therapeutic potential and mechanisms of action of drugs known as nitric oxide (NO)-aspirins. Drugs of this class have an NO-releasing moiety joined by ester linkage to the aspirin molecule. NO-aspirins have the capability to release NO in addition to retaining the cyclooxygenase-inhibitory action of aspirin. The protective nature of NO led to the development of NO-aspirins in the hope that they might avoid the gastric side effects associated with aspirin. However, it has become apparent that the drug-derived NO instills potential for a wide range of added beneficial effects over the parent compound. In this review, the authors focus on the analgesic, anti-inflammatory, cardiovascular and chemopreventative actions of compounds of this emerging drug class.

Asthma: new developments concerning immune mechanisms, diagnosis and treatment

PURPOSE OF REVIEW

This brief review discusses how recent research may modify our understanding of the immunology of asthma. Consideration is given to the possible impact that these observations may have upon diagnostic and therapeutic strategies.

RECENT FINDINGS

New studies indicate that current conceptions regarding the balance between Th1 and Th2 systems may need modification. The relationship between infection and the development of asthma in children has proven to be much more complex than originally suggested by the 'hygiene hypothesis'. In addition, important genetic differences have been found in the response of asthmatic patients to therapeutic agents.

SUMMARY

Greater insight into the mechanisms responsible for asthma and the introduction of new drugs will depend in part upon the development of reliable and simple methods for detecting airway inflammation. As the immunologic aspects of asthma are dissected, we can expect that many more potential targets for treatment will be discovered, but treatment may have to be individualized for genetic differences between different individuals.

Low level laser therapy partially restores trachea muscle relaxation response in rats with tumor necrosis factor alpha-mediated smooth airway muscle dysfunction

BACKGROUND AND OBJECTIVE

It is unknown if the decreased ability to relax airway smooth muscles in asthma and other inflammatory airways disorders can be influenced by low level laser therapy (LLLT) irradiation. To investigate if LLLT could reduce impairment in inflamed trachea smooth muscles (TSM) in rats.

STUDY DESIGN/MATERIALS AND METHODS

Controlled rat study where trachea was dissected and mounted in an organ bath apparatus with or without a TNF-alpha solution.

RESULTS

Low level laser therapy administered perpendicularly to a point in the middle of the dissected trachea with a wavelength of 655 nm and a dose of 2.6 J/cm(2), partially restored TSM relaxation response to isoproterenol. Tension reduction was 47.0 % (+/-2.85) in the laser-irradiated group compared to 22.0% (+/-2.21) in the control group (P < 0.01). Accumulation of cAMP was almost normalized after LLLT at 22.3 pmol/mg (+/-2.1) compared to 17.6 pmol/mg (+/-2.1) in the non-irradiated control group (P < 0.01).

CONCLUSION

Low level laser therapy partially restores the normal relaxation response in inflamed TSM and normalizes accumulation of cAMP in the presence of isoproterenol.

Etanercept for refractory asthma therapy

Asthma is a chronic disease of the airways in which inflammation causes bronchial hyper-reactivity and consequent asthma attacks triggered by various stimuli. The bronchospasm attacks are usually relieved by short-acting beta2 agonists, and inflammation and bronchial hyper-reactivity are reduced by maintenance therapy and, in particular, by inhaled corticosteroids. In milder asthma subjects, airway inflammation is dominated by eosinophils, whereas in more severe asthma increased neutrophil counts were detected. In severe/refractory asthma, TNF-alpha is known to play a role in the maintenance of neutrophilic inflammation and of bronchial hyper-responsiveness and is not influenced by corticosteroid therapy. Etanercept, a TNF-alpha-blocking agent, could represent one of the potential therapies for refractory asthma based on demonstrated safety and efficacy.

Oxyresveratrol dampens neuroimmune responses in vivo: a selective effect on TNF-α

Consumption of nutrients rich in hydroxystilbenes has been promoted because of their health benefits, including dampening of inflammatory responses. However, few studies have examined their effects in vivo. Here, we show that the hydroxystilbene oxyresveratrol (trans-2,3′,4,5′-tetrahydroxystilbene: o-RES) blocked hypothermia but caused no significant effect on the febrile response to the immune stimulus, bacterial LPS in rats. This was associated with a reduction in the LPS-induced plasma cytokine, tumor necrosis factor (TNF)-α, but not IL-6. Both IL-6-stimulated STAT-3 and LPS-induced cycoloxygenase-2 expression in the hypothalamus were not affected by o-RES. These data strongly suggest that the o-RES-induced dampening of neuroimmune responses is largely due to its inhibitory effect on TNF-α production. In contrast to in vitro experiments, o-RES has no direct effect on NF-κB signaling pathway in vivo. The specific inhibitory effect of o-RES on TNF-α opens new avenues for the clinical use of o-RES in pathological conditions where excessive production of TNF-α is deleterious.

The mechanisms, diagnosis, and management of severe asthma in adults

There has been a recent increase in the prevalence of asthma worldwide; however, the 5-10% of patients with severe disease account for a substantial proportion of the health costs. Although most asthma cases can be satisfactorily managed with a combination of anti-inflammatory drugs and bronchodilators, patients who remain symptomatic despite maximum combination treatment represent a heterogeneous group consisting of those who are under-treated or non-adherent with their prescribed medication. After excluding under-treatment and poor compliance, corticosteroid refractory asthma can be identified as a subphenotype characterised by a heightened neutrophilic airway inflammatory response in the presence or absence of eosinophils, with evidence of increased tissue injury and remodelling. Although a wide range of environmental factors such as allergens, smoking, air pollution, infection, hormones, and specific drugs can contribute to this phenotype, other features associated with changes in the airway inflammatory response should be taken into account. Aberrant communication between an injured airway epithelium and underlying mesenchyme contributes to disease chronicity and refractoriness to corticosteroids. The importance of identifying underlying causative factors and the recent introduction of novel therapeutic approaches, including the targeting of immunoglobulin E and tumour necrosis factor alpha with biological agents, emphasise the need for careful phenotyping of patients with severe disease to target improved management of the individual patient's needs.

The sodium/hydrogen exchanger: a possible mediator of immunity

Immune cells such as macrophages and neutrophils provide the first line of defence of the immune system using phagocytosis, cytokine and chemokine synthesis and release, as well as Reactive Oxygen Species (ROS) generation. Many of these functions are positively coupled with cytoplasmic pH (pHi) and/or phagosomal pH (pHp) modification; an increase in pHi represents an important signal for cytokine and chemokine release, whereas a decrease in pHp can induce an efficient antigen presentation. However, the relationship between pHi and ROS generation is not well understood. In immune cells two main transport systems have been shown to regulate pHi: the Na+/H+ Exchanger (NHE) and the plasmalemmal V-type H+ ATPase. NHE is a family of proteins which exchange Na+ for H+ according to their concentration gradients in an electroneutral manner. The exchanger also plays a key role in several other cellular functions including proliferation, differentiation, apoptosis, migration, and cytoskeletal organization. Since not much is known on the relationship between NHE and immunity, this review outlines the contribution of NHE to different aspects of innate and adaptive immune responses such as phagosomal acidification, NADPH oxidase activation and ROS generation, cytokine and chemokine release as well as T cell apoptosis. The possibility that several pro-inflammatory diseases may be modulated by NHE activity is evaluated.

Targeting tumour necrosis factor-alpha in corticosteroid-dependent asthma

Asthma is a chronic inflammatory disease of the airways characterised by bronchospasm attacks triggered by various stimuli. The underlying pathogenic mechanism is eosinophil-dominated inflammation causing bronchial hyper-responsiveness, but in more severe asthma subjects, neutrophil cells and their directly related cytokines, such as TNF-alpha, are known to play a role in the inflammatory process and also in diminished corticosteroid sensitivity. The bronchospasm attacks are usually relieved by short-acting beta2-agonists, whereas maintenance therapy is represented mainly by inhaled corticosteroids. However, in severe persistent asthma or in difficult to treat asthma these can be ineffective even at high doses. Therefore, other therapeutic alternatives are needed, and etanercept, a TNF-alpha blocking agent, could represent one of them provided the safety and efficacy data are supportive.

Anti-TNF-alpha and Th1 cytokine-directed therapies for the treatment of asthma

PURPOSE OF REVIEW

This article examines recent work about the role of TNF-alpha and of selected Th1-related cytokines in asthma with particular emphasis on the therapeutic potential of blocking the biological activity of these mediators.

RECENT FINDINGS

Current research endeavours suggest that asthma pathogenesis is driven by a mixed Th1/Th2 immune response. The contribution of individual Th1-associated and Th2-associated effector mechanisms to this mixed response profile is highly heterogeneous and variations in response patterns seem to be associated with heterogeneity in clinical phenotypes. In particular, it is now acknowledged that allergen-specific Th1 responses appear to be responsible for the pathogenetic effects seen in patients suffering from the more severe chronic forms of the disease. This is important because usual treatments for asthma appear to have limited effects on the more chronic severe forms of the disease and there is a pressing need for the development of new treatment strategies. The failure of topical corticosteroids to reduce TNF-alpha and Th1-derived cytokines to a significant level in asthmatic airways may explain to a certain extent why these drugs appear to have limited effects in the more severe forms of asthma.

SUMMARY

It is likely that therapies blocking TNF-alpha and interfering with Th1-derived cytokines may be a considerable advance in the management of those asthma patients who are particularly resistant to typical treatment modalities.

Inhibitory effects of coumarin and acetylene constituents from the roots of Angelica furcijuga on d-galactosamine/lipopolysaccharide-induced liver injury in mice and on nitric oxide production in lipopolysaccharide-activated mouse peritoneal macrophages

The methanolic extract (200 mg/kg, p.o. and i.p.), principal coumarin constituents (isoepoxypteryxin, anomalin, and praeroside IV), and a polyacetylene constituent (falcarindiol) (25 mg/kg, i.p.) from the roots of Angelica furcijuga protected the liver injury induced by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in mice. In in vitro experiments, coumarin constituents (hyuganins A-D, anomalin, pteryxin, isopteryxin, and suksdorfin) and polyacetylene constituents [(-)-falcarinol and falcarindiol] substantially inhibited LPS-induced NO and/or TNF-alpha production in mouse peritoneal macrophages, and isoepoxypteryxin inhibited D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. Furthermore, hyuganin A, anomalin, and isopteryxin inhibited the decrease in cell viability by TNF-alpha in L929 cells.