Transforming growth factor-beta in allergic inflammatory disease of the upper airways: friend or foe?

Polymorphism -509C/T in TGFB1 Promoter Is Associated With Increased Risk and Severity of Persistent Allergic Rhinitis in a Chinese Population

BACKGROUND

Polymorphism -509C/T in the promoter of transforming growth factor beta1 (TGFB1) gene is implicated in the pathogenesis of asthma. This polymorphism might also act to regulate the development of allergic rhinitis (AR).

OBJECTIVES

To investigate whether -509C/T is associated with AR susceptibility and severity in a Han Chinese population.

METHODS

The study enrolled 263 patients with persistent AR and 249 healthy controls. AR patients were classified as mild or moderate/severe AR groups according to the Allergic Rhinitis and its Impact on Asthma classification. TGFB1 gene polymorphism -509C/T was genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum total Immunoglobulin E (IgE) and specific IgE levels were determined using an ImmunoCAP.

RESULTS

Significant difference was found in the allele frequency of TGFB1 -509C/T between AR patients and healthy controls (P = .027) but not in the genotype frequency (P =.051). However, the genotype frequency of TGFB1 -509C/T showed significant difference between the mild AR group, the moderate/severe AR group, and the control group (P = .012); between the moderate/severe AR group and the control group (P =.036); between the mild AR group and the moderate/severe AR group (P = .038); but not between the mild AR group and the control group (P =.075).

CONCLUSION

TGFB1 promoter polymorphism -509C/T may be associated with the susceptibility and the severity of persistent AR of Han Chinese, but the functional relationship still needs clarification.

Potential Role of the Micro-Immunotherapy Medicine 2LALERG in the Treatment of Pollen-Induced Allergic Inflammation

In this study, we evaluated the efficacy of a micro-immunotherapy medicine (MIM), 2LALERG, in a preclinical model of allergic respiratory disease sensitized with birch pollen extract (BPE). BALB/c mice were immunized with BPE, or saline solution, and were then challenged. Micro-immunotherapy medicine pillules were diluted in water, and 3 doses (0.75; 1.5; 3 mg/mouse) were tested and compared to vehicle control (3 mg/mouse). Treatments and vehicle were orally administered by gavage for 10 days. Micro-immunotherapy medicine (0.75 mg/mouse) reduced the number of total cells as well as the levels of interleukin (IL)-13 in bronchoalveolar lavage fluid (BALF) compared to vehicle control. Eosinophils in BALF tended to be lower compared to vehicle group, and the difference is close to significance. Histological analysis in the lungs confirms a moderate effect of MIM (0.75 mg/mice) on inflammatory infiltration and mucus production. Serum levels of IL-5 in MIM (0.75 mg/mouse)-treated mice were lower compared to vehicle; IL-4 levels tended to be lower too. Total immunoglobulin E (IgE) decreased in serum of MIM (1.5 and 0.75 mg/mouse) groups compared to vehicle control. Micro-immunotherapy medicine exerted the highest effect at the lowest dose tested. Micro-immunotherapy medicine resolved the local and systemic inflammation, even if partially, in a model of pollen-induced, IgE-mediated inflammation.

Different effects of allergic rhinitis on nasal mucosa remodeling in chronic rhinosinusitis with and without nasal polyps

Background

Allergic rhinitis (AR) has been reported to be associated with chronic rhinosinusitis (CRS). The objective of this study was to investigate the effect of AR on nasal mucosa remodeling in CRS.

Methods

Patients were enrolled and divided into the following groups: CRS with nasal polyps (NP) with allergic rhinitis (AR)(CRSwNPwAR; n = 20), CRS with NP without AR (CRSwNPsAR; n = 20), CRS without NP with AR (CRSsNPwAR; n = 20), CRS without NP without AR (CRSsNPsAR; n = 20), AR without CRS (AR; n = 20) and controls (n = 14). Eosinophil infiltration, mucus production, and collagen deposition were examined by hematoxylin and eosin, periodic acid schiff and masson’s trichrome staining, respectively. VEGF-A and microvessel density were detected by immunohistochemistry. The expression of remodeling markers, including TGF-β1, MMP-7, MMP-9 and TIMP-1 were measured by Western blot.

Results

The expression of remodeling factors, including VEGF-A, CD31, CD34 and TIMP-1 were significantly increased in CRSwAR compared to CRSsAR. Goblet cell hyperplasia, as well as VEGF-A, CD31, CD34, and MMP-9 expression were significantly higher in CRSwNPwAR compared to CRSwNPsAR. However, the expression of collagen fibers, MMP-7 and TGF-β1 were significantly higher in CRSsNPwAR compared to CRSsNPsAR.

Conclusions

AR could enhance the remodeling process in CRS. Moreover, AR had different effects on CRSwNP and CRSsNP.

Aqueous Extract of Gumiganghwal-tang, a Traditional Herbal Medicine, Reduces Pulmonary Fibrosis by Transforming Growth Factor-β1/Smad Signaling Pathway in Murine Model of Chronic Asthma

Gumiganghwal-tang is a traditional herbal prescription that is used widely for the treatment of the common cold and inflammatory diseases in Korea and other Asian countries. In this study, we investigated the protective effects of a Gumiganghwal-tang aqueous extract (GGTA) against airway inflammation and pulmonary fibrosis using a mouse model of chronic asthma. Chronic asthma was modeled in BALB/c mice via sensitization/challenge with an intraperitoneal injection of 1% ovalbumin (OVA) and inhalation of nebulized 1% OVA for 4 weeks. GGTA (100 mg/kg or 200 mg/kg) was also administered by oral gavage once a day for 4 weeks. We investigated the number of inflammatory cells, production of T-helper type 2 (Th2) cytokines, chemokine and the total transforming growth factor-β1 (TGF-β1) in bronchoalveolar lavage fluid (BALF); the levels of immunoglobulin E (IgE) in the plasma; the infiltration of inflammatory cells in lung tissue; and the expression of TGF-β1, Smad-3, and collagen in lung tissue. Our results revealed that GGTA lowered the recruitment of inflammatory cells (particularly, lymphocyte); and decreased the production of Th2 cytokines, chemokine and total TGF-β1; and attenuated the levels of total and OVA-specific IgE; and decreased the infiltration of inflammatory cells. Moreover, GGTA significantly reduced the expression of TGF-β1 and Smad-3, and lowered collagen deposition. These results indicate that GGTA reduces airway inflammation and pulmonary fibrosis by regulating Th2 cytokines production and the TGF-β1/Smad-3 pathway, thus providing a potential treatment for chronic asthma.

Differing roles for TGF-β/Smad signaling in osteitis in chronic rhinosinusitis with and without nasal polyps

BACKGROUND

Chronic rhinosinusitis (CRS) without nasal polyps (CRSsNP) and with nasal polyps (CRSwNP) is reported to involve different inflammatory processes in sinonasal mucosa and bone tissue, and these processes remain uncharacterized.

OBJECTIVE

We aimed to investigate the molecular mechanisms of osteitis in Chinese patients with CRS to better understand the pathogenesis of CRS.

METHODS

The study included 10 controls, 16 patients with CRSsNP, and 23 patients with CRSwNP. Ethmoid bone tissue samples were evaluated by histologic examination. Quantitative real-time reverse transcription polymerase chain reaction was used to assess expression of transforming growth factor (TGF) β1, TGF-β receptor I and II, Smad2, and Smad3. Immunohistochemical examination of osteoblast expression of TGF-β1, TGF-β receptor I and II, phosphorylated (p) Smad2, and p-Smad3 in ethmoid bone tissue was also performed.

RESULTS

The histopathologic evaluation of ethmoid sinus bone tissue showed that eosinophils had infiltrated the periosteum and induced TGF-β1 expression, periosteal thickening, increased osteoblast activity, and neo-osteogenesis. Messenger RNA levels of TGF-β1, TGF-β receptor I, and Smad3 in CRSwNP ethmoid bone tissues were significantly higher than those in ethmoid bone tissues of patients with CRSsNP and the controls. Immunohistochemical staining showed that TGF-β1, TGF-β receptor I, p-Smad2, and p-Smad3 protein expression was upregulated in patients with CRSwNP, consistent with the corresponding messenger RNA levels.

CONCLUSION

Different signaling pathways are involved in osteitis in CRS and are activated by the TGF-β/Smad signaling pathway in CRSwNP versus the TGF-β/Smad-independent signaling pathway in CRSsNP. Eosinophil infiltration of the periosteum, along with TGF-β1 expression, in CRSwNP indicates that eosinophils may play an important role in the bone remodeling process in CRSwNP.

Inhibition of tumor progression during allergic airway inflammation in a murine model: significant role of TGF-β

Introduction

TGF-β is an important mediator of pulmonary allergic inflammation, and it has been recently reported to be a potential inhibitor of lung tumor progression. The correlation between cancer and allergic inflammatory diseases remains controversial. Thus, the aim of the present study was to evaluate the effects of pulmonary allergic inflammation and in particular the role of TGF-β on cancer progression.

Methods

Cancer cells were implanted in a BALB/c mice model of allergic airway inflammation, and tumor growth was measured. Apoptosis was evaluated by TUNEL assay, and TGF-β was measured by ELISA. Expression of proliferating cell nuclear antigen, TGF-β, TGF-β receptors I and II, phospho-Smad2 and phospho-Smad4 was evaluated by immunohistochemistry and quantified using digital pathology. The effect of a TGF-β activity inhibitor and recombinant TGF-β on tumor growth was analyzed. The effect of exogenous TGF-β on cell proliferation and apoptosis was evaluated in vitro.

Results

Mice with allergic airway inflammation exhibited decreased tumor volumes due to cell proliferation inhibition and increased apoptosis. TGF-β was increased in the sera and tumor tissues of allergic mice. TGF-β activity inhibition increased tumor progression in allergic mice by enhancing proliferation and decreasing apoptosis of tumor cells. The administration of TGF-β resulted in reduced tumor growth.

Conclusion

This study is the first to establish an inverse relationship between allergic airway inflammation and tumor progression. This effect appears to be mediated by TGF-β, which is overexpressed in tumor cells during pulmonary allergic inflammation. This study indicates that TGF-β is a potential target for antitumor therapy.

Electronic supplementary material

The online version of this article (doi:10.1007/s00262-015-1722-4) contains supplementary material, which is available to authorized users.

Uygur medicine Xipayi Kui Jie'an affects gene expression profiles in intestinal tissue lesions in a rat model of ulcerative colitis

Background

The aim of this study was to investigate the mechanisms underlying the therapeutic effect of Uygur medicine KJA on UC in a rat model.

Methods

UC was induced in Wistar rats by application of 2, 4-dinitrochlorobenzene and acetic acid and were then treated with three different doses of KJA, and normal saline as control. After treatment for 20 days, the gene expression profile of colonic tissue was analyzed by microarray and verified by quantitative real-time RT-PCR.

Results

Animals treated with the three different doses of KJA were compared with normal saline controls, wherein microarray analysis identified 1991, 2163, and 1677 differentially expressed genes respectively, of which 444 genes were raised and 670 genes were decrease spliced together in the three doses tested. The KEGG pathway analyses found commonly raised genes related to several different biological functions. Interesting genes included TRL2, IL-1β, TGF-β1, and NF-κB were confirmed by quantitative PCR.

Conclusions

The therapeutic effect of KJA on UC is likely explained by specific effects on the expression of genes, which are the effector molecules known to be involved in the development of UC. Further studies on differentially expressed genes will help explain the mechanism of action of Uygur medicine KJA.

Inflammatory cytokines in allergy and rhinosinusitis

PURPOSE OF REVIEW

Cytokines are involved in initiating and perpetuating the host immune response to allergens and also modulating the mucosal cellular milieu characteristic of chronic rhinosinusitis. This paper reviews the current state of knowledge regarding the most relevant cytokines in allergy and rhinosinusitis and highlights recent findings in the literature.

RECENT FINDINGS

Chronic rhinosinusitis with nasal polyps is characterized by a type 2 T helper cell cytokine polarization, whereas chronic rhinosinusitis without nasal polyps has a type 1 T helper cell cytokine expression pattern. Targeted therapies against specific cytokines such as interleukin-5 have shown promise in treating allergic diseases. Genetic polymorphisms in cytokines and their receptors have been shown to confer susceptibility to asthma and allergy. Transforming growth factor-beta has been found to have proinflammatory and anti-inflammatory effects in the nose and paranasal sinuses and appears to have a role in airway remodeling.

SUMMARY

Cytokines drive the immune system's response to allergen exposure and participate in sinonasal mucosal inflammatory conditions. Although the roles of individual cytokines in atopic disease and rhinosinusitis are becoming clearer, future studies will need to build on our knowledge of cytokine functions by focusing on therapeutic approaches to quieting the immune system and dampening the inflammatory cascade.

Simvastatin downregulates expression of TGF-βRII and inhibits proliferation of A549 cells via ERK

Lung cancer is the leading cause of cancer-related death worldwide. Transforming growth factor-β receptor II (TGF-βRII) plays an important role in the regulation of proliferation and progression in cancer. Statins have been documented to exhibit anticancer and cancer chemopreventive properties. However, the effects and mechanisms of simvastatin on the development of lung cancer are still unclear. In the present study, quiescent A549 cells were treated in vitro with fetal bovine serum (FBS) in the presence or absence of simvastatin. MTT, Western blot, and real-time qPCR were used to detect cell viability, activation of ERK, and expression of TGF-βRII at the protein and RNA level. Our results demonstrated that simvastatin inhibited activation of ERK, downregulated expression of TGF-βRII, and suppressed A549 cell proliferation. Furthermore, the effects of simvastatin can be reversed by farnesyl pyrophosphate (FPP). Therefore, these results suggest that simvastatin may inhibit A549 cell proliferation and downregulate TGF-βRII expression by inhibiting activation of ERK. Our findings may advance the current understanding of the effects of simvastatin on cancer progression and contribute to the study of cancer treatment.

TGF- β: an important mediator of allergic disease and a molecule with dual activity in cancer development

The transforming growth factor- β (TGF- β ) superfamily is a family of structurally related proteins that includes TGF- β , activins/inhibins, and bone morphogenic proteins (BMPs). Members of the TGF- β superfamily regulate cellular functions such as proliferation, apoptosis, differentiation, and migration and thus play key roles in organismal development. TGF- β is involved in several human diseases, including autoimmune disorders and vascular diseases. Activation of the TGF- β receptor induces phosphorylation of serine/threonine residues and triggers phosphorylation of intracellular effectors (Smads). Once activated, Smad proteins translocate to the nucleus and induce transcription of their target genes, regulating various processes and cellular functions. Recently, there has been an attempt to correlate the effect of TGF- β with various pathological entities such as allergic diseases and cancer, yielding a new area of research known as "allergooncology," which investigates the mechanisms by which allergic diseases may influence the progression of certain cancers. This knowledge could generate new therapeutic strategies aimed at correcting the pathologies in which TGF- β is involved. Here, we review recent studies that suggest an important role for TGF- β in both allergic disease and cancer progression.

Transforming growth factor-beta 1 pathways in inflammatory airway diseases

Transforming growth factor-beta 1 (TGF-β1) has been reported being involved in the remodeling and immunosuppression processes of inflammatory airway diseases; understanding the regulation of TGF-β1 is therefore a key to unravel the pathomechanisms of these diseases. This review briefly summarizes the current knowledge on the influencing factors for driving TGF-β1 and its regulatory pathways in inflammatory airway diseases and discusses possible therapeutic approaches to TGF-β1 control. The factors include smoking and oxidative stress, prostaglandins (PGs), leukotrienes (LTs), bradykinin (BK), and microRNAs (miRs). Based on the summary, new innovative treatment strategies may be developed for inflammatory airway diseases with an impaired expression of TGF-β1.

Bangpungtongseong-san, a traditional herbal medicine, attenuates chronic asthmatic effects induced by repeated ovalbumin challenge

Airway remodeling is characterized by airway wall thickening, subepithelial fibrosis, increased smooth muscle mass, angiogenesis and increased mucus secretion, which can lead to chronic and obstinate asthma and can obstruct pulmonary function. In this study, the effects of Bangpungtongseong-san water extract (BPTS) on airway remodeling were examined using a murine model of bronchial asthma induced by ovalbumin (OVA) challenge. We focused on the effects of BPTS on the regulation of chronic asthma. BALB/c mice were randomly assigned to 5 groups, some of which were sensitized and challenged with OVA for 4 weeks. After the final ovalbumin challenge, typical asthma-like morphological changes were observed in the lung tissue with hematoxylin and eosin staining, periodic acid-Schiff, as well as with Masson's trichrome staining. The levels of transforming growth factor-β1 (TGF-β1) and Smad3 were assessed by immunohistochemistry and western blot analysis. The expression levels of vascular endothelial growth factor (VEGF) and adhesion molecules, such as intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were also detected by western blot analysis. Our results revealed that BPTS reduced the OVA-induced increase in the infiltration of leukocytes, mucus hyperplasia and collagen deposition. Compared with the OVA-challenged group, the BPTS group had lower expression levels of adhesion molecules, TGF-β1, Smad3 and VEGF proteins in the lung tissues. The results of the current study suggest that BPTS prevents asthma airway remodeling in chronic asthma by inhibiting the activation of the TGF-β1-Smad3-signaling pathway, as well as the expression of VEGF and adhesion molecules. BPTS may thus be a potential drug for the treatment of patients with changes that occur in the airways due to severe asthma.

The effect of decellularization of tracheal allografts on leukocyte infiltration and of recellularization on regulatory T cell recruitment

Tracheal transplantation without immunosuppressive therapy has been accomplished with a tissue-engineering approach using decellularized biological scaffolds in combination with recipient progenitor cells. The mechanisms of immune response directed towards these tracheal allografts have not been fully determined. In this study, we evaluated the immunogenicity of these grafts at the protein level, and functionally, in vitro and in vivo in a large animal model. Long-segment circumferential tracheal allografts were decellularized using two different protocols and recellularized using recipient mesenchymal stromal cells (MSC) and tracheal epithelial progenitor cells (TEC). Residual MHCI and MHCII immunostaining was found surrounding the submucosal glands despite cyclical decellularization. In an in vitro lymphocyte proliferation assay, CD4+ T cells continued to proliferate on decellularized pieces and this proliferation was inhibited by co-culture with autologous MSC. Allografts were heterotopically transplanted under a muscle flap in the neck of the recipients and decellularization was found to delay leukocyte infiltration but resulted in eventual cartilage degradation. Recellularization prevented this infiltration up to 3 weeks post-transplantation and allowed for preservation of the cartilage. The immune cells found within these grafts included a significant number of CD4+CD25+Foxp3+ regulatory T cells. Furthermore, gene expression of anti-inflammatory cytokines, such as IL-10 and TGF-β1, involved in proliferation, differentiation and function of regulatory T cells was found in these grafts. These results indicate that the immunological modification induced by recellularized tracheal scaffolds is an active process involving the recruitment of immunosuppressive cells, rather than simply the removal of donor-derived antigenic components.

Epithelium and stroma from nasal polyp mucosa exhibits inverse expression of TGF-β1 as compared with healthy nasal mucosa

Objective

To evaluate TGF-β₁ expression in polypoid mucosa (epithelium and stroma) of patients with chronic rhinosinusitis with nasal polyposis (CRSwNP).

Methods

Cross-sectional study with two groups: 17 patients with nasal polyposis and 11 controls. Polyps and normal nasal mucosa were processed by immunohistochemical methods for TGF-β1 visualization. Then, the percentage of TGF-β1 expression in stroma and epithelium was objectively quantified using UT Morph software.

Results

A lower percentage of positive expression was found in the epithelium of CRSwNP patients (32.44%) versus normal controls (55.91%) (p < 0.05), and a higher percentage of positive expression in the stroma of CRSwNP patients (23.24%) versus controls (5.88%) (p < 0.05).

Conclusion

The lower percentage of TGF-β₁ expression in the nasal epithelium of CRSwNP patients may have an impact on epithelium-directed topical treatments employed in this patient population.

Convergence of two major pathophysiologic mechanisms in nasal polyposis: immune response to Staphylococcus aureus and airway remodeling

This review is addressed two pathophysiologic mechanisms implicated in the pathogenesis of nasal polyposis: the unique remodeling process found in nasal polyp tissue and the immune response of patients with nasal polyposis to Staphylococcus aureus.

These two theories converge to the same direction in different aspects, including decreased extracellular matrix production, impaired T regulation and favoring of a Th2 immune response.

In patients with nasal polyposis, an exaggerated immune response to Staphylococcus aureus may aggravate the airway remodeling process.

Asthmatic airway neutrophilia after allergen challenge is associated with the glutathione S-transferase M1 genotype

RATIONALE

Asthma is a heterogeneous lung disorder characterized by airway inflammation and airway dysfunction, manifesting as hyperresponsiveness and obstruction. Glutathione S-transferase M1 (GSTM1) is a multifunctional phase II enzyme and regulator of stress-activated cellular signaling relevant to asthma pathobiology. A common homozygous deletion polymorphism of the GSTM1 gene eliminates enzyme activity.

OBJECTIVES

To determine the effect of GSTM1 on airway inflammation and reactivity in adults with established atopic asthma in vivo.

METHODS

Nineteen GSTM1 wild-type and eighteen GSTM1-null individuals with mild atopic asthma underwent methacholine and inhaled allergen challenges, and endobronchial allergen provocations through a bronchoscope.

MEASUREMENTS AND MAIN RESULTS

The influx of inflammatory cells, panels of cytokines and chemokines linked to asthmatic inflammation, F(2)-isoprostanes (markers of oxidative stress), and IgE were measured in bronchoalveolar lavage fluid at baseline and 24 hours after allergen instillation. Individuals with asthma with the GSTM1 wild-type genotype had greater baseline and allergen-provoked airway neutrophilia and concentrations of myeloperoxidase than GSTM1-null patients. In contrast, the eosinophilic inflammation was unaffected by GSTM1. The allergen-stimulated generation of acute-stress and proneutrophilic mediators, tumor necrosis factor-α, CXCL-8, IL-1β, and IL-6, was also greater in the GSTM1 wild-type patients. Moreover, post-allergen airway concentrations of IgE and neutrophil-generated mediators, matrix metalloproteinase-9, B-cell activating factor, transforming growth factor-β1, and elastase were higher in GSTM1 wild-type individuals with asthma. Total airway IgE correlated with B-cell activating factor concentrations. In contrast, levels of F(2)-isoprostane were comparable in both groups. Finally, GSTM1 wild-type individuals with asthma required lower threshold concentrations of allergen to produce bronchoconstriction.

CONCLUSIONS

The functional GSTM1 genotype promotes neutrophilic airway inflammation in humans with atopic asthma in vivo.

Transforming growth factor-beta1 in inflammatory airway disease: a key for understanding inflammation and remodeling

Airway diseases such as chronic rhinosinusitis, asthma, and chronic obstructive pulmonary disorder are characterized by inflammation and remodeling. Among inflammatory and extracellular matrix regulatory cytokines, transforming growth factor-beta (TGF-β) stands central, as it possesses both important immunomodulatory and fibrogenic activities, and should be considered a key for understanding inflammation and remodeling processes. This review will briefly summarize the recent findings on the role of TGF-β1, from the view points of inflammation and remodeling, and discuss the role of TGF-β in the upper and lower airway diseases. This may reveal new perspectives in the understanding of airway inflammation and remodeling processes and may open innovative treatment strategies for the regulation of TGF-β1.

Transforming growth factor beta: a role in the upper airway and rhinosinusitis-Dermatophagoides pteronyssinus-induced apoptosis with pulmonary alveolar cells

BACKGROUND

There is a link with the upper and lower airway and disruption of alveolar epithelial cells, which is a potential trigger for the reactivation of the epithelial-mesenchymal trophic unit (EMTU) and induced characteristic airway changes associated with allergic asthma. Dermatophagoides pteronyssinus is a common inhalant indoor allergen and is known for causing allergic rhinitis and airway inflammation. Transforming growth factor beta 1 (TGF-beta1) is a major participant in the airway remodeling of asthma, a component of cellular stress response pathways, and enhanced epithelial immunoreactivity is known to occur in allergic rhinitis.

METHODS

In this study, we show the ability of D. pteronyssinus allergens from dialyzed standardized immunotherapy extract to induce apoptosis and increase TGF-beta1 secretion in a confluent A549 cell line model. A549 cells were treated with either 600 AU/mL dialyzed D. pteronyssinus immunotherapy extract (eDp) or Ctl media (Ctl) for 24 hours. Cells and supernatants were collected, washed, and treated with Annexin V-FITC Apoptosis Detection Kit II (BD Pharmingen, La Jolla, CA) and then analyzed by flow cytometry. TGF-beta1 secretion was determined by ELISA using cell culture supernatants.

RESULTS

The eDp group showed a fourfold increase in early apoptotic cells with a twofold increase in late apoptotic cells versus the Ctl group, along with a 1.65-fold increase of TGF-beta1.

CONCLUSION

eDp induced viable A549 cells to undergo apoptosis determined by flow cytometry analysis with a significant increase in TGF-beta1 secretion compared with Ctl.

Anti-Asthma Simplified Herbal Medicine Intervention-induced long-lasting tolerance to allergen exposure in an asthma model is interferon-γ, but not transforming growth factor-β dependent

BACKGROUND

Chronic allergic asthma is the result of a T-helper type 2 (Th2)-biased immune status. Current asthma therapies control symptoms in some patients, but a long-lasting therapy has not been established. Anti-Asthma Simplified Herbal Medicine Intervention (ASHMI™), a Chinese herbal formula, improved symptoms and lung function, and reduced Th2 responses in a controlled trial of patients with persistent moderate to severe asthma.

OBJECTIVE

We evaluated the persistence of ASHMI™ beneficial effects following therapy in a murine model of chronic asthma and the immunological mechanisms underlying such effects. Methods BALB/c mice sensitized intraperitoneally with ovalbumin (OVA) received 3 weekly intratracheal OVA challenges to induce airway hyper-reactivity (AHR) and inflammation (OVA mice). Additionally, OVA mice were treated with ASHMI™ (OVA/ASHMI™) or water (OVA/sham) for 4 weeks, and then challenged immediately and 8 weeks post-therapy. In other experiments, OVA mice received ASHMI™ treatment with concomitant neutralization of IFN-γ or TGF-β. Effects on airway responses, cytokine- and OVA-specific IgE levels were determined 8 weeks post-therapy.

RESULTS

Before treatment, OVA mice exhibited AHR and pulmonary eosinophilic inflammation following OVA challenge, which was almost completely resolved immediately after completing treatment with ASHMI™ and did not re-occur following OVA re-challenge up to 8 weeks post-therapy. Decreased allergen-specific IgE and Th2 cytokine levels, and increased IFN-γ levels also persisted at least 8 weeks post-therapy. ASHMI™ effects were eliminated by the neutralization of IFN-γ, but not TGF-β, during therapy.

CONCLUSION

ASHMI™ induced long-lasting post-therapy tolerance to antigen-induced inflammation and AHR. IFN-γ is a critical factor in ASHMI™ effects.

TGF-beta signaling may play a role in the development of goblet cell hyperplasia in a mouse model of allergic rhinitis

BACKGROUND

Transforming growth factor-beta (TGF-beta) levels are elevated in the nasal mucosa in allergic rhinitis. However, because TGF-beta is secreted extracellulary in latent complexes, it remains unclear whether the local TGF-beta expression actually drives active signaling and affects the pathophysiology of allergic rhinitis. The objective of this study is to investigate whether TGF-beta signaling is activated in allergic rhinitis and plays a role in the pathophysiology of allergic rhinitis.

METHODS

An ovabumin (OVA)-sensitized and -nasally challenged mouse model of allergic rhinitis was established and phosphorylation of Smad2 in the nasal mucosa was examined by immunohistochemistry. In addition, the effects of the pharmacological inhibition of endogenous TGF-beta signaling on the allergic rhinitis model were histologically examined. Furthermore, phosphorylation of Smad2 in the nasal mucosa samples obtained from patients with allergic rhinitis was also evaluated.

RESULTS

In the mouse model of allergic rhinitis, OVA challenge induced phosphorylation of Smad2 predominantly in epithelial cells in the nasal mucosa. In addition, the administration of an inhibitor of TGF-beta type I receptor kinase activity during OVA challenge suppressed goblet cell hyperplasia in the nasal mucosa. Furthermore, phosphorylated Smad2 expression increased in nasal epithelial cells in patients with allergic rhinitis.

CONCLUSIONS

These results suggest that TGF-beta signaling is activated in epithelial cells in the nasal mucosa in allergic rhinitis and may contribute to the development of goblet cell hyperplasia.

Exosomes from human macrophages and dendritic cells contain enzymes for leukotriene biosynthesis and promote granulocyte migration

BACKGROUND

Leukotrienes (LTs) are potent proinflammatory lipid mediators with key roles in the pathogenesis of asthma and inflammation. Recently, nanovesicles (exosomes), released from macrophages and dendritic cells (DCs), have become increasingly appreciated as messengers in immunity.

OBJECTIVE

We investigated whether exosomes from human macrophages, DCs, and plasma contain enzymes for LT biosynthesis and studied potential roles for exosomes in transcellular LT metabolism and granulocyte chemotaxis.

METHODS

The presence of LT pathway enzymes and LT biosynthesis in exosomes and cells was analyzed by Western blot, immunoelectron microscopy, and enzyme activity assays. Surface marker expression was evaluated by flow cytometry, and granulocyte migration was assessed in a multiwell chemotaxis system.

RESULTS

Exosomes from macrophages and DCs contain functional enzymes for LT biosynthesis. After incubation of intact cells with the LT biosynthesis intermediate LTA(4), LTB(4) was the major product of macrophages, whereas DCs primarily formed LTC(4). However, in exosomes from both cell types, LTC(4) was the predominant LTA(4) metabolite. Exosomal LTC(4) formation (per milligram protein) exceeded that of cells. In macrophages and DCs, TGF-β1 upregulated LTA(4) hydrolase along with increased LTB(4) formation also in the exosomes. Moreover, TGF-β1 modified the expression of surface marker proteins on cells and exosomes and reduced the exosome yield from macrophages. On Ca(2+)-ionophore and arachidonic acid stimulation, exosomes produced chemotactic eicosanoids and induced granulocyte migration. Interestingly, active LTA(4) hydrolase and LTC(4) synthase were present also in exosomes from human plasma.

CONCLUSION

Our findings indicate that exosomes can contribute to inflammation by participation in LT biosynthesis and granulocyte recruitment.

Bradykinin B(1) receptor antagonist R954 inhibits eosinophil activation/proliferation/migration and increases TGF-beta and VEGF in a murine model of asthma

In the present study the effects of bradykinin receptor antagonists were investigated in a murine model of asthma using BALB/c mice immunized with ovalbumin/alum and challenged twice with aerosolized ovalbumin. Twenty four hours later eosinophil proliferation in the bone marrow, activation (lipid bodies formation), migration to lung parenchyma and airways and the contents of the pro-angiogenic and pro-fibrotic cytokines TGF-beta and VEGF were determined. The antagonists of the constitutive B(2) (HOE 140) and inducible B(1) (R954) receptors were administered intraperitoneally 30min before each challenge. In sensitized mice, the antigen challenge induced eosinophil proliferation in the bone marrow, their migration into the lungs and increased the number of lipid bodies in these cells. These events were reduced by treatment of the mice with the B(1) receptor antagonist. The B(2) antagonist increased the number of eosinophils and lipid bodies in the airways without affecting eosinophil counts in the other compartments. After challenge the airway levels of VEGF and TGF-beta significantly increased and the B(1) receptor antagonist caused a further increase. By immunohistochemistry techniques TGF-beta was found to be expressed in the muscular layer of small blood vessels and VEGF in bronchial epithelial cells. The B(1) receptors were expressed in the endothelial cells. These results showed that in a murine model of asthma the B(1) receptor antagonist has an inhibitory effect on eosinophils in selected compartments and increases the production of cytokines involved in tissue repair. It remains to be determined whether this effects of the B(1) antagonist would modify the progression of the allergic inflammation towards resolution or rather towards fibrosis.