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3123 TGFbeta, Early Cytokine Dysregulation, and Airway Smooth Muscle Dysfunction in Cystic Fibrosis
- Elizabeth L Kramer, Rhonda Szczesniak, Weiji Su, Satish Madala, Kristin Hudock, Cynthia Davidson, Alicia Ostmann, Lauren Strecker, John P. Clancy
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- Journal:
- Journal of Clinical and Translational Science / Volume 3 / Issue s1 / March 2019
- Published online by Cambridge University Press:
- 26 March 2019, pp. 22-23
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OBJECTIVES/SPECIFIC AIMS: This study aims to first describe the unique cytokine profile and TGFbeta levels of young children with CF, then understand the pathologic effects of TGFbeta on lung function in a CF animal model. These powerful translational studies linking observations in clinical disease with a transgenic mouse model allow us a unique opportunity to investigate the role of TGFbeta in early CF lung disease. METHODS/STUDY POPULATION: Cytokine levels (TGFbeta, TNFalpha, IL-8, IL-6, HNE, and IL-1beta) in bronchoalveolar lavage fluid (BALF) from CF patients (n = 15) and non-CF control patients (n = 21) under 6 years old were determined by ELISA and Luminex assay. Tracheotomized patients without significant underlying lung disease were chosen as non-CF inflamed control patients, as they had similar levels of neutrophilic inflammation and infection as CF patients. The percentage of BAL neutrophils (% PMNs) in each sample was assessed. The relationships between cytokines were analyzed using linear regression and principal components analysis. In animal studies, CF and non-CF mice (n = 4-5 per group) were treated with intratracheal adenoviral TGFbeta1 vector, an empty vector control, or PBS. After one week, animals were collected; lung function, response to the bronchoconstrictor methacholine, and rescue with albuterol were measured utilizing a FlexiVent machine. Lungs were collected for histology. Immunohistochemistry for alpha-SMA was performed and pictures of all cross-sectional airways were obtained. Burden of ASM was assessed by dividing the square root of alpha-SMA stained airway smooth muscle by the basement membrane perimeter length of each airway. RESULTS/ANTICIPATED RESULTS: Patient characteristics of CF and non-CF inflamed control patients were similar in terms of age (3.6 yrs vs 3.3 yrs respectively, p = 0.49), positive BAL culture (13% vs 14%, p = 0.94), and % PMNs (65% vs 56%, p = 0.64). Despite these similarities, TGFbeta levels were 2-fold higher in CF versus non-CF BAL (p = 0.034). Analysis of BAL cytokines from both patient groups showed that three principal components describe 86% of total variance across the cytokine variables. These components represent different contributions from the cytokines, with TGFbeta, IL6, and % PMNs comprising one component of similarly regulated inflammatory markers. These components can distinguish CF versus non-CF patients with 77% accuracy (area under the curve: 0.77). TGFbeta concentrations were uniquely associated with increased IL-6 in CF samples (r = 0.74; p = 0.0015) but did not demonstrate association with other cytokines. After TGFbeta exposure, CF mice demonstrated greater abnormalities in airway resistance than non-CF mice, with heightened response to methacholine. Importantly, this increase in airway obstruction in CF mice was reversible with albuterol treatment, indicating airway smooth muscle dysfunction as a principal driver of lung function abnormalities. Furthermore, TGFbeta induced an increased ASM burden on lung histology in both CF and non-CF mice (p<0.05). IL-6 levels in the BAL of CF mice showed greater increases after TGFbeta treatment compared to non-CF mice (p<0.05). Empty vector control treatment did not cause lung pathology. DISCUSSION/SIGNIFICANCE OF IMPACT: Young children with CF have a unique pattern of pulmonary inflammation compared to inflamed non-CF control patients. In CF, TGFbeta pulmonary levels are uniquely associated with IL-6, a driver of ASM dysfunction in other pulmonary diseases. We followed up this clinical observation study by investigating the effect of TGFbeta on pulmonary disease in a mouse model. CF mice demonstrate increased pulmonary IL-6, airway obstruction, and ASM dysfunction after TGFbeta exposure. This study provides evidence that TGFbeta is associated with a distinct cytokine pattern that may promote ASM dysfunction in early CF lung disease. Understanding the mechanism of early CF pathophysiology will be critical in developing targeted therapeutics that can prevent early lung damage.
2045 The role of TGFβ in driving early cystic fibrosis lung disease
- Elizabeth L. Kramer, William Hardie, Kristin Hudock, Cynthia Davidson, Alicia Ostmann, John P. Clancy
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- Journal:
- Journal of Clinical and Translational Science / Volume 2 / Issue S1 / June 2018
- Published online by Cambridge University Press:
- 21 November 2018, p. 33
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OBJECTIVES/SPECIFIC AIMS: Transforming growth factor-beta (TGFβ) is a genetic modifier of cystic fibrosis (CF) lung disease. TGFβ’s pulmonary levels in young CF patients and its mechanism of action in CF are unknown. We examined TGFβ levels in children with CF and investigated responses of human airway epithelial cells (AECs) and mice to TGFβ. METHODS/STUDY POPULATION: TGFβ levels in bronchoalveolar lavage fluid from CF patients (n=15) and non-CF control patients (n=21)<6 years old were determined by ELISA. CF mice and non-CF mice were intratracheally treated with an adenoviral TGFβ1 vector or PBS; lungs were collected for analysis at day 7. Human CF and non-CF AECs were treated with TGFβ or PBS for 24 hours then collected for analysis. RESULTS/ANTICIPATED RESULTS: Young CF patients had higher bronchoalveolar lavage fluid TGFβ than non-CF controls (p=0.03). Mouse lungs exposed to TGFβ demonstrated inflammation, goblet cell hyperplasia, and decreased CFTR expression. CF mice had greater TGFβ-induced lung mechanics abnormalities than controls; both CF human AECs and CF mice showed higher TGFβ induced MAPK and PI3K signaling compared with controls. DISCUSSION/SIGNIFICANCE OF IMPACT: For the first time, we show increased TGFβ levels very early in CF. TGFβ drives CF lung abnormalities in mouse and human models; CF models are more sensitive to TGFβ’s effects. Understanding the role of TGFβ in promoting CF lung disease is critical to developing patient specific treatments.