Publications (14) View all
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Article: Vascular Endothelial Growth Factor as a Key Inducer of Angiogenesis in the Asthmatic Airways.
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ABSTRACT: Asthma is a chronic inflammatory disease of the airways characterized by structural airway changes, which are known as airway remodeling, including smooth muscle hypertrophy, goblet cell hyperplasia, subepithelial fibrosis, and angiogenesis. Vascular remodeling in asthmatic lungs results from increased angiogenesis, which is mainly mediated by vascular endothelial growth factor (VEGF). VEGF is a key regulator of blood vessel growth in the airways of asthma patients by promoting proliferation and differentiation of endothelial cells and inducing vascular leakage and permeability. In addition, VEGF induces allergic inflammation, enhances allergic sensitization, and has a role in Th2 type inflammatory responses. Specific inhibitors of VEGF and blockers of its receptors might be useful to control chronic airway inflammation and vascular remodeling, and might be a new therapeutic approach for chronic inflammatory airway disease like asthma.Current Allergy and Asthma Reports 10/2012; · 2.50 Impact Factor -
Article: Mechanisms of IFN-γ-induced apoptosis of human skin keratinocytes in patients with atopic dermatitis.
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ABSTRACT: Enhanced apoptosis of keratinocytes is the main cause of eczema and spongiosis in patients with the common inflammatory skin disease atopic dermatitis (AD). The aim of the study was to investigate molecular mechanisms of AD-related apoptosis of keratinocytes. Primary keratinocytes isolated from patients with AD and healthy donors were used to study apoptosis by using annexin V/7-aminoactinomycin D staining. Illumina mRNA Expression BeadChips, quantitative RT-PCR, and immunofluorescence were used to study gene expression. In silico analysis of candidate genes was performed on genome-wide single nucleotide polymorphism data. We demonstrate that keratinocytes of patients with AD exhibit increased IFN-γ-induced apoptosis compared with keratinocytes from healthy subjects. Further mRNA expression analyses revealed differential expression of apoptosis-related genes in AD keratinocytes and skin and the upregulation of immune system-related genes in skin biopsy specimens of chronic AD lesions. Three apoptosis-related genes (NOD2, DUSP1, and ADM) and 8 genes overexpressed in AD skin lesions (CCDC109B, CCL5, CCL8, IFI35, LYN, RAB31, IFITM1, and IFITM2) were induced by IFN-γ in primary keratinocytes. The protein expression of IFITM1, CCL5, and CCL8 was verified in AD skin. In line with the functional studies and AD-related mRNA expression changes, in silico analysis of genome-wide single nucleotide polymorphism data revealed evidence of an association between AD and genetic markers close to or within the IFITM cluster or RAB31, DUSP1, and ADM genes. Our results demonstrate increased IFN-γ responses in skin of patients with AD and suggest involvement of multiple new apoptosis- and inflammation-related factors in the development of AD.The Journal of allergy and clinical immunology 03/2012; 129(5):1297-306. · 9.17 Impact Factor -
Article: Inhibition of angiogenesis by IL-32: possible role in asthma.
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ABSTRACT: IL-32 is a proinflammatory cytokine involved in various chronic inflammatory diseases. Chronic airway inflammation in asthmatic patients results in structural airway changes, including angiogenesis. Vascular endothelial growth factor (VEGF) is a key inducer of angiogenesis in the airways of asthmatic patients. The aim of the study was to investigate the expression and function of IL-32 in patients with angiogenesis and asthma. The expression and regulation of IL-32 in normal human bronchial epithelial (NHBE) cells was analyzed by using RT-PCR, ELISA, Western blotting, immunofluorescent staining, and flow cytometry. After knockdown of IL-32 in NHBE cells by small interfering RNA (siRNA) transfections, VEGF secretion was quantified by means of ELISA. New blood vessel formation was determined with human umbilical vein endothelial cells by culturing with supernatants from IL-32 siRNA-transfected NHBE cells. IL-32 was determined in serum and induced sputum samples of asthmatic patients and healthy control subjects by means of ELISA. IL-32 is expressed in NHBE cells on stimulation with IFN-γ, TNF-α, T(H)1 cells, and rhinovirus. Inhibition of IL-32 expression resulted in significantly increased secretion of the proangiogenic factors VEGF and platelet-derived growth factor by NHBE cells. Human umbilical vein endothelial cells cultured in supernatants from IL-32 siRNA-transfected NHBE cells showed enhanced in vitro angiogenesis. IL-32 is detectable in induced sputum from asthmatic patients. IL-32 serum levels were significantly higher in asthmatic patients compared with those seen in healthy control subjects and correlated with response to asthma treatment. IL-32 is induced by IFN-γ, TNF-α, T(H)1 cells, and rhinovirus in bronchial epithelial cells. It inhibits angiogenesis, and its serum levels are associated with a good treatment response in asthmatic patients.The Journal of allergy and clinical immunology 02/2012; 129(4):964-73.e7. · 9.17 Impact Factor -
Article: Mechanisms of immune tolerance to allergens.
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ABSTRACT: In allergic diseases, immune responses are induced by normally well-tolerated allergens, which result in chronic inflammation characterized by antibody secretion and T cell activation. For almost 100 years, allergen-specific immunotherapy (allergen-SIT) has been the potentially curative and antigen-specific method for the treatment of allergic diseases. Allergen-SIT alters the course of allergic diseases and can reduce allergic symptoms and medication use. The key mechanism behind allergen-SIT is the induction of peripheral T cell tolerance by altering the balance between Th cells and regulatory T cells. Both naturally occurring thymus-derived FOXP3(+)CD4(+)CD25(+) regulatory T cells and inducible type 1 regulatory T cells suppress the development of allergic diseases via several mechanisms including suppression of dendritic cells, Th cells, mast cells, eosinophils and basophils; suppression of inflammatory cell migration to tissues; and decrease of the ratio between allergen-specific IgE and IgG4 antibodies. These effects are mainly mediated by the suppressive cytokines IL-10 and TGF-β. Knowledge of this molecular basis is crucial to understanding the regulation of the immune response and their possible therapeutic applications for allergic diseases.Progress in allergy 01/2012; 96:30-8. -
Article: Claudin-1 expression in airway smooth muscle exacerbates airway remodeling in asthmatic subjects.
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ABSTRACT: Increased airway smooth muscle (ASM) mass is an essential component of airway remodeling and asthma development, and there is no medication specifically against it. Tight junction (TJ) proteins, which are expressed in endothelial and epithelial cells and affect tissue integrity, might exist in other types of cells and display additional functions in the asthmatic lung. The aim of this study was to investigate the existence, regulation, and function of TJ proteins in ASM in asthmatic patients. The expression and function of TJ proteins in primary ASM cell lines, human bronchial biopsy specimens, and a murine model of asthma were analyzed by means of RT-PCR, multispectral imaging flow cytometry, immunohistochemistry, Western blotting, 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester staining, tritiated thymidine incorporation, wound-healing assay, and luminometric bead array. Increased claudin-1 expression was observed in ASM of asthmatic patients, as well as in a murine model of asthma-like airway inflammation. Whereas IL-1β and TNF-α upregulated claudin-1 expression, it was downregulated by the T(H)2 cytokines IL-4 and IL-13 in primary human ASM cells. Claudin-1 was localized to the nucleus and cytoplasm but not to the cell surface in ASM cells. Claudin-1 played a central role in ASM cell proliferation, as demonstrated by increased ASM cell proliferation seen with overexpression and decreased proliferation seen with small interfering RNA knockdown of claudin-1. Overexpression of claudin-1 induced vascular endothelial growth factor and downregulated IL-6, IL-8, and IFN-γ-induced protein 10 production by ASM cells. Claudin-1 upregulation by IL-1β or TNF-α was suppressed by dexamethasone but not by rapamycin, FK506, or salbutamol. These results demonstrate that claudin-1 might play a role in airway remodeling in asthmatic patients by means of regulation of ASM cell proliferation, angiogenesis, and inflammation.The Journal of allergy and clinical immunology 06/2011; 127(6):1612-21.e8. · 9.17 Impact Factor
