Asthma therapy in the new millennium

Intervention Studies of Inhaled Corticosteroids Combined with Long-acting Theophylline or Long-acting β2-agonists in Patients with Moderate to Severe Asthma: A Randomized, Controlled Study

PURPOSE

To evaluate and contrast the therapeutic effect and safety of fluticasone aerosol combined with theophylline tablets in patients with moderate to severe asthma, compared with salmeterol/fluticasone propionate aerosol.

METHODS

After a screening period, patients meeting the inclusion criteria were randomly assigned to the experiment group (fluticasone aerosol combined with theophylline tablets) or the control group (salmeterol/fluticasone aerosol combined with placebo tablets) for 12 weeks of treatment. The main outcome measurements were forced expiratory volume in 1 second and fractional concentration of exhaled nitric oxide value, whereas the secondary measures were forced vital capacity, peak expiratory flow value, and Asthma Control Test/Asthma Quality of Life Questionnaire score.

FINDINGS

Forty-four cases completed the course, with 23 cases in the experiment group and 21 cases in the control group. The forced expiratory volume in 1 second values of both groups were significantly improved from before (P < 0.05). The fractional concentration of exhaled nitric oxide values of both groups were significantly decreased from before (P < 0.05). The secondary outcome measurements after treatment achieved obvious improvement from baseline (P < 0.05) in both. There was no significant difference between the 2 groups in all measurements. In addition, the blood biochemistry results, ECG results, and vital signs of both groups had no significant abnormality.

IMPLICATIONS

There was no significant difference in therapeutic effect and safety between the 2 groups in treating patients with moderate to severe persistent asthma, which suggests that fluticasone aerosol combined with theophylline tablets is worth considering for use in primary hospitals or for low-income populations.

Inferring genome-wide functional modulatory network: a case study on NF-κB/RelA transcription factor

How different pathways lead to the activation of a specific transcription factor (TF) with specific effects is not fully understood. We model context-specific transcriptional regulation as a modulatory network: triplets composed of a TF, target gene, and modulator. Modulators usually affect the activity of a specific TF at the posttranscriptional level in a target gene-specific action mode. This action may be classified as enhancement, attenuation, or inversion of either activation or inhibition. As a case study, we inferred, from a large collection of expression profiles, all potential modulations of NF-κB/RelA. The predicted modulators include many proteins previously not reported as physically binding to RelA but with relevant functions, such as RNA processing, cell cycle, mitochondrion, ubiquitin-dependent proteolysis, and chromatin modification. Modulators from different processes exert specific prevalent action modes on distinct pathways. Modulators from noncoding RNA, RNA-binding proteins, TFs, and kinases modulate the NF-κB/RelA activity with specific action modes consistent with their molecular functions and modulation level. The modulatory networks of NF-κB/RelA in the context epithelial-mesenchymal transition (EMT) and burn injury have different modulators, including those involved in extracellular matrix (FBN1), cytoskeletal regulation (ACTN1), and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long intergenic nonprotein coding RNA, and tumor suppression (FOXP1) for EMT, and TXNIP, GAPDH, PKM2, IFIT5, LDHA, NID1, and TPP1 for burn injury.

What is new in the management of childhood asthma?

The prevalence of asthma has increased in developed countries. The efficacy of available drugs in those with severe persistent disease is limited. This has led to a renewed search for the reasons for failures of the existing treatment and for novel concepts. Treatment with inhaled corticosteroids, and to a much lesser extent theophylline, can reduce the survival of inflammatory cells including eosinophils. Emerging trends in treatments for asthma could include strategies to alter the cytokine/chemokine balance. It is evident that the current ICS are already very efficient and safe, it will be difficult to introduce further improved formulations. Perhaps the most fruitful effort shall be in developing patient friendly easy to use targeted delivery systems. The newer therapies are planned for the several upstream targets and may have potential to prevent the disease. Various potential therapies are being worked upon like-targeting prevention of T cell activation, modulation of Th-1/Th-2 differentiation, inhibition of Th-2 related cytokines, Th-1/Th-2 modulation, inhibition of downstream mediators etc. The new strategy shall perhaps lie with matching the patients and their disease with the most suitable therapy.

Sesquiterpene lactone parthenolide suppresses tumor growth in a xenograft model of renal cell carcinoma by inhibiting the activation of NF-kappaB

The transcription factor nuclear factor-kappaB (NF-kappaB) has been shown to be constitutively activated in various human malignancies, including leukemia, lymphoma and a number of solid tumors. NF-kappaB regulates the transcriptional of genes important for tumor invasion, metastasis and chemoresistance. The sesquiterpene lactone parthenolide, an inhibition of NF-kappaB, has been used conventionally to treat migraines and inflammation. In this study, renal cancer cell lines OUR-10 and ACHN were used for in vitro experiments to evaluate growth-inhibitory effects of parthenolide. An OUR-10 xenograft model in nude mice was also used to investigate the in vivo growth-inhibitory effects of parthenolide. Apoptosis in response to treatment of OUR-10 cells with parthenolide was confirmed. Localization of NF-kappaB in response to parthenolide treatment was examined of by immunofluorostaining of OUR-10 cells with antibody against NF-kappaB p65 and by Western blot analysis of OUR-10 cell and tumor nuclear and cytosol fraction. Parthenolide effectively inhibited proliferation of cultured OUR-10 cells and triggered apoptosis in vitro. Subcutaneous injection or oral administration of parthenolide showed significant tumor growth inhibition in the xenograft model via decreased production of interleukin-8 (IL-8) or vascular endothelial growth factor (VEGF). Immunohistochemistry and Western blot analysis showed decreased nuclear localization of NF-kappaB and phosphorylated NF-kappaB protein and subsequently expression of MMP-9, Bcl-xL and Cox-2 in response to parthenolide treatment. These results indicate that parthenolide is a useful in the treatment of renal cell carcinoma and acts via inhibition of NF-kappaB.

Unraveling androgen receptor interactomes by an array-based method: discovery of proto-oncoprotein c-Rel as a negative regulator of androgen receptor

The androgen receptor (AR) plays a key role in the development and function of male reproductive organs. Using a high-throughput transcription factor-transcription factor (TF-TF) interaction array method, we captured the AR interactomes in androgen-responsive LNCaP cells. Several known and unknown partners of AR, including AP-2, Pax 3/5 (BSAP), c-Rel, RREB-1, LIII BP, and NPAS2 were identified. We investigated one unreported AR-associated transcription factor, the proto-oncoprotein c-Rel, in detail. C-Rel belongs to the NF-kB/Rel families and is persistently active in a number of diseases, including cancer. The presence of c-Rel transcript, protein, and its in vitro and in vivo association with AR was determined. Co-localization of c-Rel with AR both in cytoplasm and nucleus was confirmed by indirect immunofluorescence analysis. Chromatin immunoprecipitation data indicated that c-Rel, like AR, is a part of the nucleoprotein complex regulating the androgen-responsive prostate-specific antigen (PSA) promoter. Overexpression of c-Rel downregulated the promoter activity of both PSA and GRE4-TATA-Luc plasmids in LNCaP and COS cells. Analysis of AR and c-Rel protein levels indicated that the promoter downregulation was not due to reciprocal decrease in the amounts of AR or c-Rel. In summary, we have identified several new partners of AR by using the TF-TF array method and have provided the first evidence of a functional role for c-Rel in androgen-responsive human prostate cancer cells.

Effects of capsazepine on human small airway responsiveness unravel a novel class of bronchorelaxants

Capsazepine is known as a transient receptor potential channel vanilloid subfamily 1 (TRPV(1)) antagonist that inhibits bronchoconstriction evoked in animals by TRPV(1) agonists. In this study, effects of capsazepine and chemically related analogues, so called capsazepinoids, were examined in vitro on contractile effects in human small airway preparations. Repeated cycles with 1h of LTD(4)-free physiological saline solution followed by 30min exposure to LTD(4) (10nM) demonstrated that the contractile responsiveness of the preparations exhibited little change over time despite repeated challenges (>12h). Capsazepine (1-100microM) reversibly and concentration-dependently inhibited the contractile response to LTD(4) with EC(50) approximately 10microM and approximately 90% relaxation at 100microM. Capsazepine (10microM) was approximately equally effective to attenuate the contractions evoked by several different inflammatory contractile agonists (LTD(4), PGD(2), histamine), and it relaxed preparations with established tonic contraction due to LTD(4). Higher concentrations of capsazepine were needed to relax ACh-contractions. The effect of capsazepine on LTD(4)-induced contractions was not significantly reduced by pre-treating the preparations with either of propranolol (10microM)+atropine (1microM), L-NAME (1mM), indomethacin (1microM), iberiotoxin (0.1microM), capsaicin (10microM), and nifedipine (10microM). Although the mechanism of action of the present capsazepine-induced bronchorelaxation remains unknown it emerged here that they represent a generally effective principle exerting a functional antagonism against contractile mediators but distinct from beta receptor agonists and inhibitors of L-type calcium channels. The inhibitory effect of capsazepine is shared by chemical analogues, but not with other TRPV(1) antagonists, suggesting the possibility that capsazepine represents a novel class of bronchorelaxants effective in human small airways. These findings were not predicted by previous observations that have concerned quite limited effects of capsazepine on airway tone in different animal test systems. If potency can be further increased and the results translated to in vivo, compounds representing the capsazepinoid class of bronchorelaxants might become useful in the treatment of patients suffering from asthma and COPD.

Comparison of inhaled corticosteroid combined with theophylline and double-dose inhaled corticosteroid in moderate to severe asthma

OBJECTIVE

Recent studies have found that theophylline exerts anti-inflammatory and immunomodulatory effects. This study was performed to compare the efficacy of inhaled corticosteroids (ICS) combined with slow-release theophylline (SRT) with that of double-dose ICS in asthma control, anti-inflammatory activity and safety.

METHODOLOGY

In a randomized, open, parallel, control trial, 41 patients with asthma were randomly treated with either beclomethasone dipropionate 500 microg b.i.d. (BDP group) or a combination of BDP 250 microg b.i.d and SRT 0.2 g b.i.d. (SRT/BDP group) for 6 weeks. At the start and at the end of treatment, lung function testing and sputum induction were performed, and plasma cortisol levels were measured. Sputum was analyzed for cell differential counts and the interleukin (IL)-5 level. Patients kept a record of peak expiratory flow (PEF), symptom score, and beta2-agonist use.

RESULTS

Significant increases in the morning and the evening PEF and FEV1 were observed (P < 0.05), together with an obvious reduction in symptom score and beta2-agonist use (P < 0.01). Significant decreases in the percentage eosinophils and IL-5 level in induced sputum also occurred (P < 0.05). However, there was no difference between the two groups for all these parameters. There was no significant change in the plasma cortisol level for either group.

CONCLUSIONS

Both ICS combined with SRT and double-dose ICS had the same effect on asthma control, improving symptoms and ameliorating lung function. Both therapies had similar anti-airway inflammatory effects and therapeutic safety. Combining SRT with ICS may allow a reduction in ICS dose when treating asthma.

New anti-inflammatory therapies and targets for asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) are diseases of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma and COPD is still rising and is predicted to continue to rise in the foreseeable future. Beta-agonists and corticosteroids form the basis of the therapies available to treat asthma. However, the treatments available for COPD, corticosteroids and anticholinergics, reduce the number and severity of exacerbations, but have a limited effect on slowing the progression of the disease. The inflammatory processes underlying the pathology of asthma have received a great deal of attention and more recently, those underlying COPD have begun to be elucidated. This has resulted in the identification of new targets that will allow the development of novel approaches by the pharmaceutical industry, which will be able to focus its efforts in an attempt to provide new and improved therapies to treat these debilitating diseases. The resultant therapies should impinge on the underlying development of these diseases rather than providing symptomatic relief or palliative treatment alone. This review will outline new targets and novel approaches currently under investigation, which may provide opportunities for novel anti-inflammatory therapeutic interventions that slow or halt disease progression in asthma and COPD.

Inhibitors of mitogen-activated protein kinases differentially regulate costimulated T cell cytokine production and mouse airway eosinophilia

Background

T cells play a dominant role in the pathogenesis of asthma. Costimulation of T cells is necessary to fully activate them. An inducible costimulator (ICOS) of T cells is predominantly expressed on Th2 cells. Therefore, interference of signaling pathways precipitated by ICOS may present new therapeutic options for Th2 dominated diseases such as asthma. However, these signaling pathways are poorly characterized in vitro and in vivo.

Methods

Human primary CD4⁺ T cells from blood were activated by beads with defined combinations of surface receptor stimulating antibodies and costimulatory receptor ligands. Real-time RT-PCR was used for measuring the production of cytokines from activated T cells. Activation of mitogen activated protein kinase (MAPK) signaling pathways leading to cytokine synthesis were investigated by western blot analysis and by specific inhibitors. The effect of inhibitors in vivo was tested in a murine asthma model of late phase eosinophilia. Lung inflammation was assessed by differential cell count of the bronchoalveolar lavage, determination of serum IgE and lung histology.

Results

We showed in vitro that ICOS and CD28 are stimulatory members of an expanding family of co-receptors, whereas PD1 ligands failed to co-stimulate T cells. ICOS and CD28 activated different MAPK signaling cascades necessary for cytokine activation. By means of specific inhibitors we showed that p38 and ERK act downstream of CD28 and that ERK and JNK act downstream of ICOS leading to the induction of various T cell derived cytokines. Using a murine asthma model of late phase eosinophilia, we demonstrated that the ERK inhibitor U0126 and the JNK inhibitor SP600125 inhibited lung inflammation in vivo. This inhibition correlated with the inhibition of Th2 cytokines in the BAL fluid. Despite acting on different signaling cascades, we could not detect synergistic action of any combination of MAPK inhibitors. In contrast, we found that the p38 inhibitor SB203580 antagonizes the action of the ERK inhibitor U0126 in vitro and in vivo.

Conclusion

These results demonstrate that the MAPKs ERK and JNK may be suitable targets for anti-inflammatory therapy of asthma, whereas inhibition of p38 seems to be an unlikely target.

The role of branched polyesters and their modifications in the development of modern drug delivery vehicles

Branched polyesters consisting of poly (vinyl alcohol) (PVA) grafted with chains of poly (lactic-co-glycolic acid) (PLGA) represent a new class of biodegradable polymers showing significant potential for the development of a variety of drug delivery vehicles. The amphiphilic character and the resulting increase in hydrophilicity of this class of polymers provide advantages when packaging sensitive drug molecules, such as proteins, peptides or DNA. Furthermore, the PVA backbone can be modified, for example, with sulfobutyl moieties or amine structures, to create polymers with negative or positive charges. The ability to modify not only the backbone but also the length of the PLGA side chains results in an extremely flexible polymer system, which can be adapted to meet the needs of almost any drug substance. Further, the rate of biodegradation may also be manipulated through polymer modification to achieve half-lives ranging from several hours to several weeks. This review provides an overview of the three major groups of branched polyesters based upon poly (vinyl alcohol)-grafted poly (lactic-co-glycolic acid) (PVA-g-PLGA), namely, the neutrally charged PVA-g-PLGA, the negatively charged sulfobutyl-modified PVA-g-PLGA and the positively charged amine-modified PVA-g-PLGA, as well as their use in various drug delivery systems.

New advances and potential therapies for the treatment of asthma

Asthma is a disease of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma is still rising and is predicted to continue to rise in the current century. Inhaled beta(2)-adrenoceptor agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma. There is a need for novel, safe treatments to tackle the underlying inflammation that characterizes asthma pathology. Furthermore, there is a requirement for new treatments to be developed as oral therapy in order to alleviate patient compliance issues, especially in children. A multitude of new approaches and new targets are being investigated, which may provide opportunities for novel therapeutic interventions in this debilitating disease. For simplicity, these approaches can be divided into two categories. The first comprises therapies directed against specific components or steps seen in allergic asthma. By 'components' we mean the key inflammatory cells (T cells [in particular T(h)2], B cells, eosinophils, mast cells, basophils and antigen presenting cells [APC]) and mediators (immunoglobulin E [IgE], cytokines, histamines, leukotrienes and prostanoids) believed to be involved in the chronic inflammation seen in asthma. By 'steps' we mean the allergic response, such as antigen processing and presentation, T(h)2-cell activation, B-cell isotype switching, mast cell involvement and airway remodeling. The other category of novel approaches to disease modification in asthma encompasses general anti-inflammatory therapies including phosphodiesterase 4 (PDE4) inhibitors, p38 mitogen-activated protein kinase (MAPK) inhibitors, peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, and lipoxins.

Review of the unique properties of budesonide

BACKGROUND

The aim of inhaled corticosteroid (ICS) therapy for asthma is to attain high therapeutic activity in the airways while keeping the risk of systemic adverse effects relatively low. However, the physicochemical and pharmacokinetic properties of various ICSs affect this ratio, thereby influencing their ability to fulfill the requirements of an ideal agent.

OBJECTIVE

This article reviews the physical and pharmacokinetic properties of budesonide, outlining how they, safety data, and use of different inhalation devices enable budesonide to meet many of the clinical requirements of an ideal ICS for the treatment of asthma.

RESULTS

ICS efficacy is influenced by lipophilicity, lung deposition, and retention in airway tissue, whereas the rate of elimination determines systemic activity. Budesonide is retained in the airways to a greater extent than other ICSs because of an esterification process that increases its lipophilicity. The prolonged retention of budesonide in the airways may contribute to its efficacy when administered QD. In addition to a pressurized metered-dose inhaler, budesonide is available as a dry-powder inhaler and in nebulized form, which can be used by asthma patients aged > or =6 months.

CONCLUSIONS

When combined with delivery devices suitable for a spectrum of patient groups, the physical and pharmacokinetic properties of budesonide lend it many of the characteristics of an ideal ICS, including favorable efficacy and tolerability profiles.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Inhibition of CCL11, CCL24, and CCL26-induced degranulation in HL-60 eosinophilic cells by specific inhibitors of MEK1/MEK2, p38 MAP kinase, and PI 3-kinase

Eosinophilic leukocytes are the cellular hallmark of allergic inflammation. Apart from being potent eosinophils chemoattractants, the eotaxins CCL11, CCL24 and CCL26 are capable of activating eosinophils to generate reactive oxygen species, lipid mediators of inflammation and degranulation of toxic granule proteins. Due to their central role in eosinophil trafficking and activation, understanding the signal transduction mechanism of the eotaxin-induced eosinophil effector functions may provide an innovative therapeutic strategy for eosinophil-associated diseases. Thus, these investigations were conducted to delineate signal transduction mechanisms of CCL11, CCL24 and CCL26-induced eosinophil peroxidase (EPO) degranulation following pretreatment of cells with or without a specific inhibitor of MEK1/MEK2 (U0126), inhibitor of p38 MAP kinase (SB203580) or a specific inhibitor of PI 3-kinase (LY294002). Results have shown that CCR3-mediated eotaxin-induced eosinophilic degranulation was concentration-dependently reduced by specific inhibitors of ERK1/ERK2, p38 MAP kinase and PI 3-kinase. However, the rank order of U0126 with respect to inhibition of chemokine-induced degranulation was CCL11 = CCL24 > CCL26. Potentiation of eotaxin-induced EPO degranulation by IL-5 was also seen. These investigations have not only confirmed the reported co-operativity between IL-5 and the eotaxins but also showed that the eosinophil-degranulating capabilities of the eotaxin CCL11, CCL24 and CCL26 is a consequence of activation of ERK1/ERK2, p38 MAP kinase and PI 3-kinase. Thus, these signaling molecules may provide the biochemical basis for mechanism-based therapy of allergic inflammatory diseases.

Novel therapies for the treatment of inflammatory airway disease

Asthma and chronic obstructive pulmonary disease (COPD) are diseases of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma and COPD is still rising and is predicted to continue to rise in the current century. The beta-agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma, whereas the treatments available for COPD have been shown to have a limited effect on slowing the progression of the disease. Asthma and COPD are both in need of novel, safe treatments to tackle the underlying inflammation that characterises their pathology. The inflammatory processes inherent in asthma and COPD provide the opportunity for innovative drug research. This review will outline the new approaches and targets being investigated, which may provide opportunities for novel therapeutic interventions in these debilitating diseases.