Fatty acid fingerprints in bronchoalveolar lavage fluid and its extracellular vesicles reflect equine asthma severity

Abstract

Equine asthma (EA) is an inflammatory disease of the lower airways driven by mediators released from cells. Extracellular vesicles (EVs) are vehicles for lipid mediators, which possess either pro-inflammatory or dual anti-inflammatory and pro-resolving functions. In this study, we investigated how the respiratory fatty acid (FA) profile reflects airway inflammatory status. The FA composition of bronchoalveolar lavage fluid (BALF), BALF supernatant, and bronchoalveolar EVs of healthy horses (n = 15) and horses with mild/moderate EA (n = 10) or severe EA (SEA, n = 5) was determined with gas chromatography and mass spectrometry. The FA profiles distinguished samples with different diagnoses in all sample types, yet they were insufficient to predict the health status of uncategorized samples. Different individual FAs were responsible for the discrimination of the diagnoses in different sample types. Particularly, in the EVs of SEA horses the proportions of palmitic acid (16:0) decreased and those of eicosapentaenoic acid (20:5n-3) increased, and all sample types of asthmatic horses had elevated dihomo-γ-linolenic acid (20:3n-6) proportions. The results suggest simultaneous pro-inflammatory and resolving actions of FAs and a potential role for EVs as vehicles for lipid mediators in asthma pathogenesis. EV lipid manifestations of EA can offer translational targets to study asthma pathophysiology and treatment options.

Tetraspanin profiles of serum extracellular vesicles reflect functional limitations and pain perception in knee osteoarthritis

“…As multicollinearity between variables might, in principle, confound the estimation of featuresʼ importance in RF classification, we sampled the variable groups (Fig. 1 ) to create a 1000-fold enriched dataset with only 6 features, one representing each group of variables as detailed in [ 54 ] (see also the “ Materials and methods ” section). This approach eliminates de facto a large fraction of the multicollinearity in the data and, at the same time, increases the size of the dataset.…”

“…RF analysis was performed using the sklearn Python package, following our approach published in [ 54 ]. To build the RF classifier, we used the following parameters: n_estimators = 100, criterion = ‘entropy’, max_depth = None, min_samples_split = 2, min_samples_leaf = 1, min_weight_fraction_leaf = 0.0, max_features = 6, max_leaf_nodes = None, min_impurity_decrease = 0.0, bootstrap = True, oob_score = False, n_jobs = − 1, random_state = None, verbose = 0, warm_start = False, class_weight = None, ccp_alpha = 0.0, max_samples = None.…”

“…As detailed in [ 54 ], we took advantage of the strong intra-group correlations between the different variables to enrich the original dataset 1000-fold, by sampling each group only once and by repeating the operation 1000 times until we obtained a reduced dataset of 6 features only (number of groups) but encompassing 1000 more pseudo-subjects (hereafter referred to as the 1000 × dataset). We next verified that the information encoded in the 6-features data was equivalent to that of the full dataset by randomly splitting the enriched 1000 × dataset in training (80% of the pseudo-subjects) and testing data (20%).…”

Metabolomics in Animal Models of Bronchial Asthma and Its Translational Importance for Clinics

“…Several endotypes and phenotypes of equine asthma have even been recognized [ 189 , 191 ]. To enhance laboratory verification of equine asthma or to differentiate the asthma endotypes and phenotypes, several metabolomic studies have been recently published [ 86 , 192 , 193 ], demonstrating significant changes in lipid metabolites.…”

Lipids in Equine Airway Inflammation: An Overview of Current Knowledge

“…Lipidomics have been used to investigate mechanisms and treatments of asthma and other lung diseases in humans [ 9 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], whilst studies in horses have included lipid and/or fatty acid (FA) compositions of plasma, surfactant [ 11 , 22 ], bronchoalveolar lavage fluid (BALF) cells [ 23 ], and BALF extracellular vesicles (EVs) [ 24 ] from horses affected by different types and severities of airway inflammation. The aim of this review article is to explore the basic concepts of biologically active lipids in the equine body, with special emphasis on the role of lipids in inflammation, and to collect and summarize the findings of recent lipidomic studies on equine airway inflammation.…”