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Vitamin D Levels in Children with Asthma, Atopic Dermatitis, and Food Allergy
AB44 Abstracts
SATURDAY
172
PGE2 May Decrease Airway Inflammation and Muscular Hyperplasia in Eosinophilic Bronchitis Patients through Prostanoid Receptors EP2 and EP4 ´ NDEZ-NIETO M.1,2, LO ´ PEZ E.1,2, GA ´ MEZ SASTRE B.1,2, FERNA C.1,2, AGUADO E.1,2, QUIRCE S.3,2, SASTRE J.1,2, DEL POZO V.1; 1 ´ N JIME´NEZ-DI´AZ, MADRID, SPAIN, 2CIBER de EnferFUNDACIO medades Respiratorias (CIBERES), Madrid, SPAIN, 3HOSPITAL UNIVERSITARIO LA PAZ, MADRID, SPAIN. RATIONALE: Eosinophilic bronchitis (EB) is characterized by chronic cough and sputum eosinophilia without bronchial hyperresponsiveness. Patients with EB show increased levels of prostaglandin E2 (PGE2) in sputum supernatant compared with asthmatic subjects. PGE2 could play a protective role in this disorder. METHODS: Twenty-one patients with EB, 16 asthmatic patients and 12 healthy subjects were studied. We analyzed PGE2 receptors (EP2 and EP4) by Real-Time PCR from peripheral blood eosinophils, induced sputum and bronchial biopsies. Also, receptor expression was analyzed by confocal microscopy and flow cytometry in peripheral blood eosinophils. Moreover, we tested the effect of sputum supernatants from EB and asthmatic patients on bronchial smooth muscle cells (BSMC) proliferation. RESULTS: Patients with EB showed higher mRNA expression levels of EP2 and EP4 than asthmatic patients in peripheral blood eosinophils (7.78 and 10.86-fold), in sputum cells (2.02 and 1.36-fold) and in bronchial biopsies (1.85 and 2.38-fold). Also, an elevated expression of EP2 and EP4 in eosinophils of EB patients with respect to asthmatic patients was observed by flow cytometry. When BSMC were cultured with EB sputum supernatants an important inhibition of BSMC proliferation was observed when compared with asthmatic sputum supernatants (60.33% vs 48.92%; p<0.05). CONCLUSIONS: The protective role of PGE2 in eosinophilic bronchitis is probably exerted through EP2 and EP4. PGE2 inhibits BSMC proliferation entailing a reduction of smooth muscle hyperplasia and preventing airflow obstruction. These results may open novel therapeutic approaches to inflammatory respiratory diseases.
173 174
Withdrawn
Tie2-mediated Downstream Effects in Airway Epithelial Cells and Potential Regulation of Tie2 by Flt3L in Asthmatic Airways T. O. Makinde, D. K. Agrawal; Creighton University School of Medicine, Omaha, NE. RATIONALE: Elevated levels of angiopoietin (Ang) 1 and 2 in asthmatic airways correlate with the severity of airway occlusion. We recently found that Tie-2 tyrosine kinase receptor (Tie2) expression in asthmatic airway epithelial cells (AECs) correlate with the features of airway remodeling. Also, Flt3 ligand (Flt3L) reverses airway hyperresponsiveness (AHR) and airway remodeling. Here, we examined the relationship between the reversal of pathophysiological changes and Tie2 expression, and the downstream effects of Tie-2-mediated signaling in AECs. METHODS: Lung tissues were isolated from three groups of Balb/c mice: PBS, OVA-sensitized and challenged, and OVA-sensitized and challenged mice treated with Flt3L. Lung sections were analyzed for Tie2 expression using immunofluorescence. BEAS-2b AECs were transfected to over express Tie2 and these cells were treated with Ang 1 and 2 alone and in combination with transforming growth factor (TGF)-b and epidermal growth factor (EGF). Functional properties of AECs, such as proliferation, migration and wound healing, were analyzed following treatment. RESULTS: No detectable expression of Tie2 was found in the lung of PBS mice. Tie2 expression was significantly up-regulated in AECs of OVA-sensitized and challenged mice. This was reversed by administration of mice with Flt3L. Constitutive expression of Tie2 was found in the vasculature of all three groups of mice. Ang2 significantly increased migration, inhibited TGF-b-induced apoptosis and attenuated EGF-induced proliferation and wound healing in Tie2 over-expressed BEAS-2b cells.
J ALLERGY CLIN IMMUNOL FEBRUARY 2010
CONCLUSIONS: Tie-2 signaling in AECs in allergic asthmatic lung can lead to aberrant cellular functions that contribute to exacerbation of inflammation and airway remodeling in chronic asthma.
175
Moderate Intensity Aerobic Exercise Training Increases CD4+CD25+Foxp3+ Regulatory T cell Responses in Asthmatic Mice L. M. Schwiebert, K. Dugger, T. W. Lowder, K. Estell; University of Alabama at Birmingham, Birmingham, AL. RATIONALE: We have reported that moderate intensity aerobic exercise training attenuates asthma-related responses. Recent studies implicate CD4+CD25+ regulatory T (Treg) cells in decreasing airway inflammation and hyperresponsiveness; therefore, the current study examined the effect of exercise on CD4+CD25+ Treg cell function in a murine asthma model. METHODS: CD4+CD25+ Treg cells were isolated from TLUX mice, which contain T cells that express a luciferase reporter gene, and adoptively transferred into recipients. Recipients were sensitized with ovalbumin (OVA) prior to exercise training at a moderate intensity 3x/week for 4 wks; exercise was performed as treadmill running (13.5 m/min, 0% grade). Throughout the protocol, mice were OVA challenged; concomitantly, changes in CD4+CD25+ Treg cell distribution were monitored via bioluminescence imaging. At protocol completion, mice were analyzed for changes in the distribution and suppressive function of CD4+CD25+ Treg cells isolated from lungs, mediastinal lymph nodes (MLN), and spleens. RESULTS: Exercise increased significantly the number of CD4+CD25+ Treg cells within the pulmonary compartment of OVA-treated mice as compared with sedentary controls (p 0.05). CD4+CD25+ Treg cells from the lungs, MLN, and/or spleens of exercised, OVA-treated mice suppressed CD4+CD25- cell proliferation and production of Th1 and Th2 cytokines, chemokines, and growth factors in vitro more effectively as compared with sedentary controls (p 0.01). CONCLUSIONS: These data demonstrate that exercise-mediated increases in Treg cell function may play a role in the attenuation of asthmatic responses. Future studies will define the mechanisms that underlie exercise-mediated increases in CD4+CD25+ Treg cell homing and suppressive function in vivo.
176
Vitamin D Levels in Children with Asthma, Atopic Dermatitis, and Food Allergy D. A. Searing, J. Murphy, P. Hauk, D. Y. M. Leung; National Jewish Health, Denver, CO. RATIONALE: There is evidence that vitamin D insufficiency may contribute to the pathophysiology of allergic disease. Further knowledge is needed in children about the variables associated with vitamin D insufficiency. METHODS: We performed a retrospective analysis of 25-hydroxyvitamin D [25(OH)D] levels in 99 patients aged 0-18 years with asthma, atopic dermatitis (AD), and/or food allergy (FA). Demographic and clinical data were recorded. Multivariate linear regression was used to determine an efficient model associating demographic and clinical factors with 25(OH)D levels. RESULTS: 56% of patients had insufficient levels of 25(OH)D (<30 ng/ mL) and 17% were deficient (<20 ng/mL). In linear regression analysis, 25(OH)D levels were inversely correlated with age (p < 0.0001) and number of positive environmental skin prick tests (p 5 0.03), but were directly correlated with FEV1/FVC ratio (p 5 0.04). Trends approaching significance were noted for lower vitamin D levels and higher log IgE level, latitude, and BMI. After controlling for significant demographic factors in the multivariate model (age, latitude), the presence of asthma was significantly correlated with lower vitamin D levels (p 5 0.047). Amongst asthmatics, vitamin D levels were inversely correlated with taking an inhaled corticosteroid (p 5 0.036). CONCLUSIONS: Vitamin D insufficiency is common in children with asthma and allergies. The diagnosis of asthma and taking an inhaled corticosteroid were significantly correlated with lower vitamin D levels. Future trials are needed to determine appropriate vitamin D supplementation in children and its impact on disease management.
SATURDAY
172
PGE2 May Decrease Airway Inflammation and Muscular Hyperplasia in Eosinophilic Bronchitis Patients through Prostanoid Receptors EP2 and EP4 ´ NDEZ-NIETO M.1,2, LO ´ PEZ E.1,2, GA ´ MEZ SASTRE B.1,2, FERNA C.1,2, AGUADO E.1,2, QUIRCE S.3,2, SASTRE J.1,2, DEL POZO V.1; 1 ´ N JIME´NEZ-DI´AZ, MADRID, SPAIN, 2CIBER de EnferFUNDACIO medades Respiratorias (CIBERES), Madrid, SPAIN, 3HOSPITAL UNIVERSITARIO LA PAZ, MADRID, SPAIN. RATIONALE: Eosinophilic bronchitis (EB) is characterized by chronic cough and sputum eosinophilia without bronchial hyperresponsiveness. Patients with EB show increased levels of prostaglandin E2 (PGE2) in sputum supernatant compared with asthmatic subjects. PGE2 could play a protective role in this disorder. METHODS: Twenty-one patients with EB, 16 asthmatic patients and 12 healthy subjects were studied. We analyzed PGE2 receptors (EP2 and EP4) by Real-Time PCR from peripheral blood eosinophils, induced sputum and bronchial biopsies. Also, receptor expression was analyzed by confocal microscopy and flow cytometry in peripheral blood eosinophils. Moreover, we tested the effect of sputum supernatants from EB and asthmatic patients on bronchial smooth muscle cells (BSMC) proliferation. RESULTS: Patients with EB showed higher mRNA expression levels of EP2 and EP4 than asthmatic patients in peripheral blood eosinophils (7.78 and 10.86-fold), in sputum cells (2.02 and 1.36-fold) and in bronchial biopsies (1.85 and 2.38-fold). Also, an elevated expression of EP2 and EP4 in eosinophils of EB patients with respect to asthmatic patients was observed by flow cytometry. When BSMC were cultured with EB sputum supernatants an important inhibition of BSMC proliferation was observed when compared with asthmatic sputum supernatants (60.33% vs 48.92%; p<0.05). CONCLUSIONS: The protective role of PGE2 in eosinophilic bronchitis is probably exerted through EP2 and EP4. PGE2 inhibits BSMC proliferation entailing a reduction of smooth muscle hyperplasia and preventing airflow obstruction. These results may open novel therapeutic approaches to inflammatory respiratory diseases.
173 174
Withdrawn
Tie2-mediated Downstream Effects in Airway Epithelial Cells and Potential Regulation of Tie2 by Flt3L in Asthmatic Airways T. O. Makinde, D. K. Agrawal; Creighton University School of Medicine, Omaha, NE. RATIONALE: Elevated levels of angiopoietin (Ang) 1 and 2 in asthmatic airways correlate with the severity of airway occlusion. We recently found that Tie-2 tyrosine kinase receptor (Tie2) expression in asthmatic airway epithelial cells (AECs) correlate with the features of airway remodeling. Also, Flt3 ligand (Flt3L) reverses airway hyperresponsiveness (AHR) and airway remodeling. Here, we examined the relationship between the reversal of pathophysiological changes and Tie2 expression, and the downstream effects of Tie-2-mediated signaling in AECs. METHODS: Lung tissues were isolated from three groups of Balb/c mice: PBS, OVA-sensitized and challenged, and OVA-sensitized and challenged mice treated with Flt3L. Lung sections were analyzed for Tie2 expression using immunofluorescence. BEAS-2b AECs were transfected to over express Tie2 and these cells were treated with Ang 1 and 2 alone and in combination with transforming growth factor (TGF)-b and epidermal growth factor (EGF). Functional properties of AECs, such as proliferation, migration and wound healing, were analyzed following treatment. RESULTS: No detectable expression of Tie2 was found in the lung of PBS mice. Tie2 expression was significantly up-regulated in AECs of OVA-sensitized and challenged mice. This was reversed by administration of mice with Flt3L. Constitutive expression of Tie2 was found in the vasculature of all three groups of mice. Ang2 significantly increased migration, inhibited TGF-b-induced apoptosis and attenuated EGF-induced proliferation and wound healing in Tie2 over-expressed BEAS-2b cells.
J ALLERGY CLIN IMMUNOL FEBRUARY 2010
CONCLUSIONS: Tie-2 signaling in AECs in allergic asthmatic lung can lead to aberrant cellular functions that contribute to exacerbation of inflammation and airway remodeling in chronic asthma.
175
Moderate Intensity Aerobic Exercise Training Increases CD4+CD25+Foxp3+ Regulatory T cell Responses in Asthmatic Mice L. M. Schwiebert, K. Dugger, T. W. Lowder, K. Estell; University of Alabama at Birmingham, Birmingham, AL. RATIONALE: We have reported that moderate intensity aerobic exercise training attenuates asthma-related responses. Recent studies implicate CD4+CD25+ regulatory T (Treg) cells in decreasing airway inflammation and hyperresponsiveness; therefore, the current study examined the effect of exercise on CD4+CD25+ Treg cell function in a murine asthma model. METHODS: CD4+CD25+ Treg cells were isolated from TLUX mice, which contain T cells that express a luciferase reporter gene, and adoptively transferred into recipients. Recipients were sensitized with ovalbumin (OVA) prior to exercise training at a moderate intensity 3x/week for 4 wks; exercise was performed as treadmill running (13.5 m/min, 0% grade). Throughout the protocol, mice were OVA challenged; concomitantly, changes in CD4+CD25+ Treg cell distribution were monitored via bioluminescence imaging. At protocol completion, mice were analyzed for changes in the distribution and suppressive function of CD4+CD25+ Treg cells isolated from lungs, mediastinal lymph nodes (MLN), and spleens. RESULTS: Exercise increased significantly the number of CD4+CD25+ Treg cells within the pulmonary compartment of OVA-treated mice as compared with sedentary controls (p 0.05). CD4+CD25+ Treg cells from the lungs, MLN, and/or spleens of exercised, OVA-treated mice suppressed CD4+CD25- cell proliferation and production of Th1 and Th2 cytokines, chemokines, and growth factors in vitro more effectively as compared with sedentary controls (p 0.01). CONCLUSIONS: These data demonstrate that exercise-mediated increases in Treg cell function may play a role in the attenuation of asthmatic responses. Future studies will define the mechanisms that underlie exercise-mediated increases in CD4+CD25+ Treg cell homing and suppressive function in vivo.
176
Vitamin D Levels in Children with Asthma, Atopic Dermatitis, and Food Allergy D. A. Searing, J. Murphy, P. Hauk, D. Y. M. Leung; National Jewish Health, Denver, CO. RATIONALE: There is evidence that vitamin D insufficiency may contribute to the pathophysiology of allergic disease. Further knowledge is needed in children about the variables associated with vitamin D insufficiency. METHODS: We performed a retrospective analysis of 25-hydroxyvitamin D [25(OH)D] levels in 99 patients aged 0-18 years with asthma, atopic dermatitis (AD), and/or food allergy (FA). Demographic and clinical data were recorded. Multivariate linear regression was used to determine an efficient model associating demographic and clinical factors with 25(OH)D levels. RESULTS: 56% of patients had insufficient levels of 25(OH)D (<30 ng/ mL) and 17% were deficient (<20 ng/mL). In linear regression analysis, 25(OH)D levels were inversely correlated with age (p < 0.0001) and number of positive environmental skin prick tests (p 5 0.03), but were directly correlated with FEV1/FVC ratio (p 5 0.04). Trends approaching significance were noted for lower vitamin D levels and higher log IgE level, latitude, and BMI. After controlling for significant demographic factors in the multivariate model (age, latitude), the presence of asthma was significantly correlated with lower vitamin D levels (p 5 0.047). Amongst asthmatics, vitamin D levels were inversely correlated with taking an inhaled corticosteroid (p 5 0.036). CONCLUSIONS: Vitamin D insufficiency is common in children with asthma and allergies. The diagnosis of asthma and taking an inhaled corticosteroid were significantly correlated with lower vitamin D levels. Future trials are needed to determine appropriate vitamin D supplementation in children and its impact on disease management.