Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease

Background: Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls. Hypothesis/Objectives: Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD). Animals: Recurrent airway obstruction-affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client-owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited. Methods: Pulmonary function and BALF were evaluated from control and RAO-affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client-owned horses (RAO-affected horses, n = 17; IAD-affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots. Results: Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO-affected horses than in IAD-affected and control horses. Conclusions and Clinical Importance: Secretoglobin and transferrin expression is decreased in BALF of RAO-affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease

Secretoglobin and Transferrin Expression in Bronchoalveolar Lavage Fluid of Horses with Chronic Respiratory Disease

Background: Lower expression of secretoglobin and transferrin has been found in the bronchoalveolar lavage fluid (BALF) of a small number of horses with experimentally induced signs of recurrent airway obstruction (RAO) compared to healthy controls. Hypothesis/Objectives: Secretoglobin and transferrin BALF expression will be similarly decreased in horses with naturally occurring clinical signs of RAO and in horses with experimentally induced clinical signs of RAO as compared to healthy controls and intermediate in horses with inflammatory airway disease (IAD). Animals: Recurrent airway obstruction-affected and control horses were subjected to an experimental hay exposure trial to induce signs of RAO. Client-owned horses with a presumptive diagnosis of RAO and controls from the same stable environments were recruited. Methods: Pulmonary function and BALF were evaluated from control and RAO-affected research horses during an experimental hay exposure trial (n = 5 in each group) and from client-owned horses (RAO-affected horses, n = 17; IAD-affected horses, n = 19; healthy controls, n = 5). The concentrations of secretoglobin and transferrin in BALF were assessed using Western blots. Results: Naturally occurring and experimentally induced RAO horses had similar decreases in BALF transferrin expression, but secretoglobin expression was most decreased in naturally occurring RAO. Secretoglobin and transferrin expression were both lower in BALF of RAO-affected horses than in IAD-affected and control horses. Conclusions and Clinical Importance: Secretoglobin and transferrin expression is decreased in BALF of RAO-affected horses after both experimental and natural exposure. Secretoglobin and transferrin likely play clinically relevant roles in the pathophysiology of RAO, and may thus be used as biomarkers of the disease

Microarray molecular mapping of horses with severe asthma

International audienceBackground :Severe asthma (SA) in horses, resembling human asthma, is a prevalent, debilitating allergic respiratory condition marked by elevated allergen‐specific immunoglobulin E (IgE) against environmental proteins; however, research exploring the exposome's influence on IgE profiles is currently limited but holds paramount significance for diagnostic and therapeutic developments. Animals: Thirty‐five sports horses were analyzed, consisting of environmentally matched samples from France (5 SA; 6 control), the United States (6 SA; 6 control), and Canada (6 SEA; 6 control). Methods : This intentional cross‐sectional study investigated the sensitization profiles of SA‐affected and healthy horses via serological antigen microarray profiling. Partial least square‐discriminant analysis (PLS‐DA) was used to identify and rank the importance of allergens for class separation (ie, affected/non‐affected) as variable influence of projection (VIP), and allergen with commonality internationally established via frequency analysis. Results: PLS‐DA models showed high discriminatory power in predicting SA in horses from Canada (area under the curve [AUC] 0.995) and France (AUC 0.867) but poor discriminatory power in horses from the United States (AUC 0.38). Hev b 5.0101, Cyn D, Der p 2, and Rum cr were the only shared allergens across all geographical groups. Conclusions and clinical importance : Microarray profiling can identify specific allergenic components associated with SA in horses, while mathematical modeling of this data can be used for disease classification, highlighting the variability of sensitization profiles between geographical locations and emphasizing the importance of local exposure to the prevalence of different allergens. Frequency scoring analysis can identify important variables that contribute to the classification of SA across different geographical regions

Comparison of genomic and proteomic data in recurrent airway obstruction affected horses using ingenuity pathway analysis

Background: Recurrent airway obstruction (RAO) is a severe chronic respiratory disease affecting horses worldwide, though mostly in the Northern hemisphere. Environmental as well as genetic factors strongly influence the course and prognosis of the disease. Research has been focused on characterization of immunologic factors contributing to inflammatory responses, on genetic linkage analysis, and, more recently, on proteomic analysis of airway secretions from affected horses. The goal of this study was to investigate the interactions between eight candidate genes previously identified in a genetic linkage study and proteins expressed in bronchoalveolar lavage fluid (BALF) collected from healthy and RAO-affected horses. The analysis was carried out with Ingenuity Pathway Analysis bioinformatics software. Results: The gene with the greatest number of indirect interactions with the set of proteins identified is Interleukin 4 Receptor (IL-4R), whose protein has also been detected in BALF. Interleukin 21 receptor and chemokine (C-C motif) ligand 24 also showed a large number of interactions with the group of detected proteins. Protein products of other genes like that of SOCS5, revealed direct interactions with the IL-4R protein. The interacting proteins found in several pathways are reported regulators of the nfb pathway. Conclusions: The pathways generated highlight possible important intracellular signaling cascades implicating, for instance, nfb. Furthermore, the proposed interaction between SOCS5 and IL-4R could explain how different genes can lead to identical clinical RAO phenotypes, as observed in two Swiss Warmblood half sibling families because these proteins interact upstream of an important cascade where they may act as a functional unit

Comparison of genomic and proteomic data in recurrent airway obstruction affected horses using ingenuity pathway analysis\u3csup\u3e®\u3c/sup\u3e

Background: Recurrent airway obstruction (RAO) is a severe chronic respiratory disease affecting horses worldwide, though mostly in the Northern hemisphere. Environmental as well as genetic factors strongly influence the course and prognosis of the disease. Research has been focused on characterization of immunologic factors contributing to inflammatory responses, on genetic linkage analysis, and, more recently, on proteomic analysis of airway secretions from affected horses. The goal of this study was to investigate the interactions between eight candidate genes previously identified in a genetic linkage study and proteins expressed in bronchoalveolar lavage fluid (BALF) collected from healthy and RAO-affected horses. The analysis was carried out with Ingenuity Pathway Analysis® bioinformatics software. Results: The gene with the greatest number of indirect interactions with the set of proteins identified is Interleukin 4 Receptor (IL-4R), whose protein has also been detected in BALF. Interleukin 21 receptor and chemokine (C-C motif) ligand 24 also showed a large number of interactions with the group of detected proteins. Protein products of nother genes like that of SOCS5, revealed direct interactions with the IL-4R protein. The interacting proteins NOD2, RPS6KA5 and FOXP3 found in several pathways are reported regulators of the NFkB pathway. Conclusions: The pathways generated with IL-4R highlight possible important intracellular signaling cascades implicating, for instance, NFkB. Furthermore, the proposed interaction between SOCS5 and IL-4R could explain how different genes can lead to identical clinical RAO phenotypes, as observed in two Swiss Warmblood half sibling families because these proteins interact upstream of an important cascade where they may act as a functional unit

Proteomic analysis of bronchoalveolar lavage fluid in an equine model of asthma during a natural antigen exposure trial

Background Heaves is a complex, asthma-like respiratory disease that affects many older horses. While environmental and genetic components to the disease have been proposed, the specific pathophysiology of heaves is still poorly understood. Using proteomic techniques, we compared the protein profile of bronchoalveolar lavage fluid (BALF) in the lungs of healthy horses and horses affected with heaves. Methods Clinical signs of the disease were induced in heaves-affected horses using an experimental hay exposure model.  Samples of BALF were collected from all horses before and after the hay exposure trial. Mass spectrometry (LC-MS) was used to evaluate the differences in the global BALF peptide profile between the control and heaves-affected horses. Tandem mass spectrometry (LC-MS/MS) was used to identify differentially expressed proteins in the two groups of horses. The identification of two proteins was validated with Western blot assays. Results One hundred peptides were differentially expressed between healthy controls and heaves-affected horses; 76 peptides were over-expressed in controls and 24 were over-expressed in heaves-affected horses. The identifications of transferrin and secretoglobin were confirmed with Western blot. Conclusions This study demonstrates that proteomics can be used to compare the protein profiles of BALF from healthy and diseased horses. These techniques may prove helpful in determining the pathophysiology of complex diseases

Allergy to natural rubber latex in severe equine asthma patients

International audienceBackground: Natural rubber latex (NRL) allergy has become an important occupational health problem in humans, with a higher prevalence in asthmatic individuals. However, the occurrence of NRL sensitisation in horses with severe equine asthma (sEA), a condition comparable to human allergic asthma, is unknown.Method: Specific IgE levels against 10 different Hev b proteins were measured in sera from n = 57 sEA-affected and n = 81 non-affected horses using a microarray platform. Slides were scanned in a GenePix® 4000B with GenePix® Pro 6 software. Multivariant modeling was used to rank the importance of individual allergens.Results: Modelling revealed a high association of Hev b 11, Hev b 6.02 and Hev b 5.0101 allergies in severe equine asthma patients. Given the adjuvant and sensitising effects of latex, these airborne particles could contribute to the increase in both latex sensitisation and asthma through direct and indirect mechanisms. The source of sensitisation to latex is yet to be determined, however the equine environment is ubiquitous with artificial riding surfaces which often contains shredded rubber.Conclusion: This study demonstrated a high prevalence of in vitro NRL allergies within the severe equine asthma population. At present, exposure should be considered a potential risk to the respiratory health of the horse

DNA binding activity of transcription factors in bronchial cells of horses with recurrent airway obstruction.

Horses with recurrent airway obstruction (RAO) present many similarities with human asthmatics including airway inflammation, hyperresponsiveness, reversible obstruction, and increased NF-kappaB expression. Studies in experimental asthma models have shown that transcriptions factors such as activator protein-1 (AP-1), GATA-3, cyclic AMP response element binding protein (CREB) and CAAT/enhancer binding protein (C/EBP) may also play an important role in airway inflammation. The purpose of this study was to measure DNA binding activity of these transcription factors in the airways of horses with RAO and to compare it to pulmonary function and bronchoalveolar lavage fluid (BALF) cytology. Seven horses with RAO and six control animals were studied during a moldy hay challenge and after 2 months at pasture. Pulmonary function, BALF cytology and transcription factors' activities in bronchial brushings were measured during hay and pasture exposures. During moldy hay challenge, RAO-affected horses developed severe airway obstruction and inflammation and a significantly higher airway AP-1 binding activity than in controls. After 2 months on pasture, pulmonary function and airway AP-1 binding activity were not different between RAO and control horses. The DNA binding activity of CREB in airways of RAO-affected horses increased significantly after 2 months at pasture and became higher than in controls. A significant positive correlation was detected between AP-1 binding activity and indicators of airway obstruction and inflammation. Airway GATA-3, CEBP and CREB binding activities were negatively correlated with indices of airway obstruction. However, contrarily to CREB binding activity, GATA-3 and CEBP binding activities were not different between RAO and control horses and were unaffected by changes in environment. These data support the view that AP-1 and CREB play a role in modulating airway inflammation in horses with RA