Gabriel Moran1, Carolina Carcamo2, Margarita Concha3, Hugo Folch4. 1. Department of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile. Electronic address: gmoran@uach.cl. 2. Department of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile. 3. Department of Biochemistry, Faculty of Science, Universidad Austral de Chile, Valdivia, Chile. 4. Department of Immunology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile.
Abstract
BACKGROUND: Serum amyloid A (SAA) is an acute phase protein that is elevated in blood during inflammation. The role of this protein in allergic diseases of airways remains unclear. AIMS: The objective of this study was to evaluate the SAA in blood, lung and bronchial cells in a murine model of bronchial hypersensitivity to Aspergillus fumigatus. METHODS: To achieve this purpose, different groups of 5-month-old mice were housed in cages containing hay bedding that was contaminated with A. fumigatus and were kept in an isolation room for 16 days to allow for the induction of allergic airway inflammation. Subsequently, the mice were then exposed once again to Aspergillus spores at 0, 2, 8, 24 and 72 h, and they were bled to acquire serum and sacrificed to obtain bronchoalveolar lavage fluid (BALF) or lung tissues for analysis. SAA levels were measured in lung, serum and BALF by dot blot assay and RT-PCR (reverse transcription polymerase chain reaction). RESULTS: The results indicated that SAA protein levels increased in both serum and lung within 2-24h after mice were exposed to Aspergillus spores. Moreover, the SAA mRNA expression levels in the lungs and BALF cells demonstrated the same trend that was observed for the protein levels through the dot blot assay; in particular, SAA mRNA levels increased within the first hour after mice were exposed to A. fumigatus. CONCLUSIONS: In this allergic airway model, we conclude that A. fumigatus can induce an acute inflammatory response in the airways through the stimulation of the SAA protein, increasing its levels in serum, lung tissue and BALF samples during the early hours of exposure of mice that have been sensitised for this fungus.
BACKGROUND:Serum amyloid A (SAA) is an acute phase protein that is elevated in blood during inflammation. The role of this protein in allergic diseases of airways remains unclear. AIMS: The objective of this study was to evaluate the SAA in blood, lung and bronchial cells in a murine model of bronchial hypersensitivity to Aspergillus fumigatus. METHODS: To achieve this purpose, different groups of 5-month-old mice were housed in cages containing hay bedding that was contaminated with A. fumigatus and were kept in an isolation room for 16 days to allow for the induction of allergic airway inflammation. Subsequently, the mice were then exposed once again to Aspergillus spores at 0, 2, 8, 24 and 72 h, and they were bled to acquire serum and sacrificed to obtain bronchoalveolar lavage fluid (BALF) or lung tissues for analysis. SAA levels were measured in lung, serum and BALF by dot blot assay and RT-PCR (reverse transcription polymerase chain reaction). RESULTS: The results indicated that SAA protein levels increased in both serum and lung within 2-24h after mice were exposed to Aspergillus spores. Moreover, the SAA mRNA expression levels in the lungs and BALF cells demonstrated the same trend that was observed for the protein levels through the dot blot assay; in particular, SAA mRNA levels increased within the first hour after mice were exposed to A. fumigatus. CONCLUSIONS: In this allergic airway model, we conclude that A. fumigatus can induce an acute inflammatory response in the airways through the stimulation of the SAA protein, increasing its levels in serum, lung tissue and BALF samples during the early hours of exposure of mice that have been sensitised for this fungus.
Keywords:
Airway inflammation; Alergia; Allergy; Aspergillus fumigatus; Inflamación de las vías respiratorias; Proteína amiloide A sérica; Serum amyloid A
Authors: E Arellano-Orden; C Calero Acuña; V Sánchez-López; C López Ramírez; R Otero-Candelera; C Marín-Hinojosa; Jl López Campos Journal: Eur Clin Respir J Date: 2022-07-08