Novel therapies for the treatment of inflammatory airway disease

Increased expression of Siglec-9 in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common inflammatory lung disease. Sialic acid-binding immunoglobulin-type lectins 9 (Siglec-9) is predominantly expressed on innate immune cells and has been shown to exert regulatory effect on immune cells through glycan recognition. Soluble Siglec-9 (sSiglec-9), the extracellular region of Siglec-9, might fulfill its function partly by competitive inhibiting siglec-9 binding to its ligands; however, the role of Siglec-9 and sSiglec-9 in the pathogenesis COPD remain largely unknown. In this study, we showed that Siglec-9 expression in alveolar and peripheral blood neutrophil were increased in COPD patients by immunofluorescence and flow cytometry, respectively. Plasma levels of sSiglelc-9 were elevated in COPD patients by ELISA. In vitro, Siglec-9 expression and/or sSiglelc-9 levels were up-regulated by cigarette smoke extract (CSE), lipopolysaccharide (LPS), some cytokines, and dexamethasone (DEX). Recombinant sSiglce-9 increased oxidative burst in neutrophil and enhanced neutrophil chemotaxis toward IL-8 independent on CXCR1 and CXCR2 expression, but it did not affect neutrophil apoptosis or secretions of inflammatory cytokines. In conclusion, Siglec-9 was complementarily increased to induce a negative feedback loop to limit neutrophil activation in COPD, sSiglce-9 enhanced neutrophil ROS and chemotaxis toward IL-8 likely via competitively inhibiting ligands binding to Siglec-9.

The Isosteroid Alkaloid Imperialine from Bulbs of Fritillaria cirrhosa Mitigates Pulmonary Functional and Structural Impairment and Suppresses Inflammatory Response in a COPD-Like Rat Model

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the world. Present therapies for COPD have limited effect on reducing the progression of COPD and suppressing the inflammatory response in the lung. Bulbs of Fritillaria cirrhosa D. Don (BFC) have been used in many Asian countries for a long time to treat pulmonary diseases, such as cough, expectoration, and asthma. Steroidal alkaloids are the major biological active constituents in BFC, whereby imperialine is one of the important steroidal alkaloids. So far, there are no studies reporting the effect of imperialine on COPD. In this study, we investigated the effect of imperialine on pulmonary function and structure and inflammation in a COPD-like rat model which was induced by the combination of exposure to CS and intratracheal administration of LPS. Our data show that imperialine mitigates pulmonary functional and structural impairment and suppressed inflammatory response in a COPD-like rat model by mediating expression of related cytokines in lung tissues of the COPD-like rats, such as IL-1β, IL-6, IL-8, TNF-α, NF-κB, TGF-β1, MMP-9, and TIMP-1.

COPD: the patient perspective

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by nonreversible airway obstruction. Well-characterized symptoms such as exertional dyspnea and fatigue have a negative impact on patients' quality of life (QoL) and restrict physical activity in daily life. The impact of COPD symptoms on QoL is often underestimated; for example, 36% of patients who describe their symptoms as being mild-to-moderate also admit to being too breathless to leave the house. Additionally, early morning and nighttime symptoms are a particular problem. Methods are available to allow clinicians to accurately assess COPD symptoms, including patient questionnaires. Integrated approaches to COPD management, particularly pulmonary rehabilitation, are effective strategies for addressing symptoms, improving exercise capacity and, potentially, also increasing physical activity. Inhaled bronchodilators continue to be the mainstay of drug therapy in COPD, where options can be tailored to meet patients' needs with careful selection of the inhaled medication and the device used for its delivery. Overall, an integrated approach to disease management should be considered for improving QoL and subsequent patient outcomes in COPD.

Bioactive lipid profiling reveals drug target engagement of a soluble epoxide hydrolase inhibitor in a murine model of tobacco smoke exposure

The inflammatory process underlying chronic obstructive pulmonary disease (COPD) may be caused by tobacco smoke (TS) exposure. Previous studies show that epoxyeicosatrienoic acids (EETs) possess promising anti-inflammatory properties, therefore stabilization of EETs and other fatty acid epoxides through inhibition of soluble epoxide hydrolase (sEH) was investigated in mouse models of acute and sub-chronic inflammation caused by TS exposure. During the entire TS exposure, the potent sEH inhibitor 1-(1-methylsulfonyl-piperidin-4-yl)-3-(4-trifluoromethoxy-phenyl)-urea (TUPS) was given via drinking water. To assess drug target engagement of TUPS, a tandem mass spectrometry method was used for bioactive lipid profiling of a broad range of fatty acid metabolites, including EETs, and their corresponding diols (DHETs) derived from arachidonic acid, as well as epoxides and diols derived from other fatty acids. Several, but not all, plasma epoxide/diol ratios increased in mice treated with sEH inhibitor, compared to non-treated mice suggesting a wider role for sEH involving more fatty acid precursors besides arachidonic acid. This study supports qualitative use of epoxide/diol ratios explored by bioactive lipid profiling to indicate drug target engagement in mouse models of TS exposure relevant to COPD, which may have ramifications for future therapeutic interventions of sEH.

Use of a soluble epoxide hydrolase inhibitor in smoke-induced chronic obstructive pulmonary disease

Tobacco smoke-induced chronic obstructive pulmonary disease (COPD) is a prolonged inflammatory condition of the lungs characterized by progressive and largely irreversible airflow limitation attributable to a number of pathologic mechanisms, including bronchitis, bronchiolitis, emphysema, mucus plugging, pulmonary hypertension, and small-airway obstruction. Soluble epoxide hydrolase inhibitors (sEHIs) demonstrated anti-inflammatory properties in a rat model after acute exposure to tobacco smoke. We compared the efficacy of sEHI t-TUCB (trans-4-{4-[3-(4-trifluoromethoxy-phenyl)-ureido]-cyclohexyloxy}-benzoic acid) and the phosphodiesterase-4 (PDE4) inhibitor Rolipram (Biomol International, Enzo Life Sciences, Farmingdale, NY) to reduce lung injury and inflammation after subacute exposure to tobacco smoke over a period of 4 weeks. Pulmonary physiology, bronchoalveolar lavage, cytokine production, and histopathology were analyzed to determine the efficacy of sEHI and Rolipram to ameliorate tobacco smoke-induced inflammation and injury in the spontaneously hypertensive rat. Both t-TUCB and Rolipram inhibited neutrophil elevation in bronchoalveolar lavage. sEHI t-TUCB suppressed IFN-γ, while improving lung function by reducing tobacco smoke-induced total respiratory resistance and tissue damping (small-airway and peripheral tissue resistance). Increases in tobacco smoke-induced alveolar airspace size were attenuated by t-TUCB. Rolipram inhibited the production of airway mucus. Both t-TUCB and Rolipram inhibited vascular remodeling-related growth factor. These findings suggest that sEHI t-TUCB has therapeutic potential for treating COPD by improving lung function and attenuating the lung inflammation and emphysematous changes caused by tobacco smoke. To the best of our knowledge, this is the first report to demonstrate that sEHI exerts significant protective effects after repeated, subacute tobacco smoke-induced lung injury in a rat model of COPD.

Antibiotic therapy for exacerbations of chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is already the world's fourth most common cause of mortality and likely to become the third in a few year's time. Because it is an inflammatory airway disease with altered host immune response, infectious complications are frequent. Acute exacerbations of COPD (AECOPD) significantly worsen the patient's general health, accelerating disability. Each exacerbation leads progressively to further deterioration of lung function. Among the various causes of AECOPD, including viruses, bacteria and air pollution, a bacterial etiology is most common (50-69%). The management of AECOPD remains extremely challenging and places a heavy economic burden on health care institutions. The decision to administer antibiotics in AECOPD is multifactorial, the most important considerations being severity of the COPD stage and patient performance status, clinical symptoms (increased dyspnea, sputum volume and sputum purulence), severity of current and previous exacerbations, comorbidity and current smoking. Exacerbations which require hospital admission are associated with significant in-patient mortality. AECOPD patients presenting with worsening dyspnea, increased sputum volume and purulence should be offered antimicrobial therapy. If treating with antibiotics, treatment must include coverage for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in all cases, but other bacteria (such as Gram-negatives) may need to be covered depending on the condition of the patient. Antibiotics, particularly macrolides and fluoroquinolones, when administered under suitable conditions, shorten the clinical course and prevent severe deterioration. possible complications resulting from untreated severe AECOPD surpass the potential risks from the use of antibiotic therapy. Additional anti-inflammatory and immunomodulatory actions of some antibiotics may contribute to their efficacy in AECOPD.

Corticosteroids (inhaled and/or intranasal) in the treatment of respiratory allergy in children: safety vs. efficacy

BACKGROUND

Topical administration of Corticosteroids (CS) can reduce the total dose of CS required to treat the patient and minimize side effects. Topical CS is extremely effective and has an excellent safety profile. Nonetheless, care must be taken when multiple sites such as lungs, nose and skin are being treated. CS mechanisms of action on the inflammatory process are complex. The aim of this study is to review such mechanisms and the adverse events secondary to it.

METHODS

Review English database (Embase, PubMed, Scielo) searching words: CS, adverse events, inhaled CS, intranasal CS, and children.

RESULTS

There is a classic mechanism involving a genomic effect of CS and a non-genomic effect, independently of gene transcription process. This mechanism acts by reducing mucosal blood flow in the asthmatic airways. Second-generation topical CS is the treatment of choice in allergic diseases control because of their good anti-inflammatory activity, poor absorption and first-pass hepatic metabolism. When comparing different CS, it is important to compare therapeutically equivalent doses. Although topical CS reduces systemic side effects, local and even systemic side effects can occur. Many factors affect the amount of drug that reaches the lung, including inhaler technique and inhaler type, fine particle dose and particle distribution.

CONCLUSION

Most patients with allergic diseases respond to CS treatment, but there is a small subset of them whose response is unsatisfactory even with high doses of CS. They are classified as corticosteroid-resistant asthmatics. Pro-inflammatory cytokines appear to up regulate the expression of GRb that has been associated with CS resistance.

The treatment of asthma in children: inhaled corticosteroids

The evidence that asthma is characterized by extensive inflammation of the airways has warranted the use of inhaled corticosteroid (ICS) in asthma maintenance therapy. Corticosteroid treatment, especially if high or frequent doses are required, is associated with a range of adverse effects including adrenal suppression and impairment in growth and bone metabolism. New corticosteroids are in development, including mometasone furoate, and some of these are predicted to have reduced adverse effects such as the soft steroid ciclesonide. Soft steroids are designed for delivery near to their site of action, to exert their effect and then to undergo controlled and predictable metabolism to inactive metabolites. This review points out the anti-inflammatory effects of corticosteroid in asthmatic airways and the clinical efficacy and safety of ICS in asthmatic children. The development of a soft steroid should help to achieve the aim of improving the therapeutic profile of ICS in asthma and thus alleviate the ongoing problem of poor patient compliance especially in childhood.

Steroid-resistant Inflammation in a Rat Model of Chronic Obstructive Pulmonary Disease Is Associated with a Lack of Nuclear Factor-κB Pathway Activation

RATIONALE

Emphysema is one component of chronic obstructive pulmonary disease (COPD), a respiratory disease currently increasing in prevalence worldwide. The mainstay therapy adopted to treat patients with COPD is glucocorticoids; unfortunately, this treatment has limited impact on disease symptoms or underlying airway inflammation.

OBJECTIVE

There is an urgent need to develop therapies that modify both the underlying inflammation, thought to be involved in disease progression, and the structural changes in the emphysematous lung.

METHODS

We have characterized an elastase-driven model of experimental emphysema in the rat that demonstrates COPD-like airway inflammation and determined the impact of a clinically relevant glucocorticoid.

MEASUREMENTS AND MAIN RESULTS

We observed an increase in lung neutrophils, lymphomononuclear cells, mucus production, and inflammatory cytokines. Also present were increases in average air space area, which are associated with emphysema-like changes in lung function, such as increased residual volume and decreased flow; these increases in area were maintained for up to 10 weeks. In addition, we observed that elastase-induced airway neutrophilia is steroid resistant. Interestingly, the inflammation observed after elastase administration was found to be temporally associated with a lack of nuclear factor-kappaB pathway activation. This apparent nuclear factor-kappaB-independent inflammation may explain why treatment with a glucocorticoid was ineffective in this preclinical model and could suggest parallels in the steroid-resistant human disease.

CONCLUSION

We believe that this model, in addition to its suitability for testing therapies that may modify existing emphysema, could be useful in the search for new therapies to reduce the steroid-resistant airway inflammation evident in COPD.

Modulation of neutrophil and inflammation markers in chronic obstructive pulmonary disease by short-term azithromycin treatment

The anti-inflammatory potential of azithromycin in chronic obstructive pulmonary disease (COPD) patients was explored following a standard oral dosing regimen. Patients with moderate and severe COPD were treated with azithromycin (500 mg, n=16) or placebo (n=8) once daily for 3 days in a randomized, double blind design, to compare effects on inflammation markers with those seen in a previous study in healthy volunteers. A battery of tests was made on serum, blood neutrophils and sputum on days 1 (baseline), 3, 4, 11, 18 and 32. In comparison to placebo, azithromycin resulted in an early transient increase in serum nitrites plus nitrates (day 3), associated with a tendency towards an increase in the blood neutrophil oxidative burst to phorbol myristic acetate. Subsequently, prolonged decreases in blood leukocyte and platelet counts, serum acute phase protein (including C reactive protein) and soluble E-selectin and blood neutrophil lactoferrin concentrations and a transient decrease in serum interleukin-8 were observed. Blood neutrophil glutathione peroxidase activity showed a prolonged increase after azithromycin treatment. The biphasic facilitatory-then-inhibitory response to azithromycin seen in healthy volunteers is not so clearly detectable in COPD patients, only potential anti-inflammatory effects. Treatment for longer periods may give therapeutic anti-inflammatory benefit in these patients.

Novel, potent and selective anilinoquinazoline and anilinopyrimidine inhibitors of p38 MAP kinase

SAR studies led to the identification of 4-(3-benzoylamino-6-methyl-anilino)quinazolines as potent and selective inhibitors of p38 MAP kinase. Further optimisation led to the identification of a series of 4-(3-benzoylamino-6-methyl-anilino)pyrimidines as potent inhibitors of the p38 MAP kinase signalling pathway in vitro and in vivo.

Design, synthesis, and biological evaluation of new phosphodiesterase type 4 inhibitors

The design, synthesis, and biological evaluation of new phosphodiesterase type 4 inhibitors, which possess new templates instead of a cyclohexane ring, are described. The mode of interaction with the enzyme is discussed based on the structure-activity relationship (SAR) data obtained for the synthesized inhibitors. Furthermore, the roles of three pharmacophores, a catechol moiety, a nitrile moiety, and acidic moieties, are discussed using in silico docking studies. More detailed biological evaluations of selected compounds are also presented.

Soft steroids: a new approach to the treatment of inflammatory airways diseases

Inhaled synthetic glucocorticosteroids are widely used in the treatment of bronchial asthma where they provide very effective first line treatment. However, a range of unwanted side effects and the often complex dosing schedules associated with these drugs frequently result in poor patient compliance. The soft drug approach has been utilised as a means of delivering these potent anti-inflammatory agents close to their site of action while reducing the degree of systemic exposure and thus limiting or eliminating the associated systemic and local side effects. A further target for pharmaceutical companies is to deliver these new treatments in a once daily formulation thus further enhancing patient compliance. While many soft steroids have failed to progress into the clinic two are meeting with some degree of success. Loteprednol etabonate, an inactive metabolite soft steroid, has been accepted for the treatment of ophthalmic disorders and is being examined in clinical trials for its effects on airway inflammation. Ciclesonide, a pro-drug soft steroid, has demonstrated efficacy without side effects in a once daily formulation in asthma patients and is being developed for the treatment of both asthma and chronic obstructive pulmonary disease with launches of a once daily inhaler formulation expected in 2003. These drugs may represent a significant step forward in the treatment of inflammatory diseases of the airways.