Background Asthma is characterized by increased airway narrowing in response to nonspecific stimuli. The disorder is influenced by both environmental and genetic factors. Exosomes are nanosized ...vesicles of endosomal origin released from inflammatory and epithelial cells that have been implicated in asthma. In this study we characterized the microRNA (miRNA) content of exosomes in healthy control subjects and patients with mild intermittent asthma both at unprovoked baseline and in response to environmental challenge. Objective To investigate alterations in bronchoalveolar lavage fluid (BALF) exosomal miRNA profiles due to asthma, and following subway air exposure. Methods Exosomes were isolated from BALF from healthy control subjects (n = 10) and patients with mild intermittent asthma (n = 10) after subway and control exposures. Exosomal RNA was analyzed by using microarrays containing probes for 894 human miRNAs, and selected findings were validated with quantitative RT-PCR. Results were analyzed by using multivariate modeling. Results The presence of miRNAs was confirmed in exosomes from BALF of both asthmatic patients and healthy control subjects. Significant differences in BALF exosomal miRNA was detected for 24 miRNAs with a subset of 16 miRNAs, including members of the let-7 and miRNA-200 families, providing robust classification of patients with mild nonsymptomatic asthma from healthy subjects with 72% cross-validated predictive power (Q2 = 0.72). In contrast, subway exposure did not cause any significant alterations in miRNA profiles. Conclusion These studies demonstrate substantial differences in exosomal miRNA profiles between healthy subjects and patients with unprovoked, mild, stable asthma. These changes might be important in the inflammatory response leading to bronchial hyperresponsiveness and asthma.
Background Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide and is increasing, primarily among women. Underdiagnosis is common, and because of the ...heterogeneous disease characteristics, molecular markers of specific disease phenotypes and more efficacious treatment regimens are urgently needed. Objective In this study the soluble proteome of bronchoalveolar lavage cells, primarily consisting of macrophages, was investigated with the aim of identifying phenotypic differences in early disease development. Methods Two-dimensional difference gel electrophoresis was used for relative quantification of protein levels, and multivariate modeling was applied to identify proteins of interest that were subsequently identified by means of liquid chromatography–mass spectrometry. Results Significant gender differences were unveiled, with numerous alterations in the bronchoalveolar lavage cell proteome occurring in female but not male patients with COPD. Specifically, a subset of 19 proteins provided classification of female healthy smokers from female patients with COPD with 78% predictive power. Subsequent pathway analyses linked the observed alterations to downregulation of the lysosomal pathway and upregulation of the oxidative phosphorylation pathway, possibly linking dysregulation of macroautophagy to a female-dominated COPD disease phenotype. Conclusion This investigation makes an important contribution to the elucidation of putative molecular mechanisms underlying gender-based differences in the pathophysiology of COPD, linking alterations of specific molecular pathways to previously observed gender differences in clinical COPD phenotypes. Furthermore, these results stress the importance of the gender-specific search for biomarkers, diagnosis, and treatment in COPD.
Background Sarcoidosis is an inflammatory granulomatous disorder characterized by accumulation of TH 1-type CD4+ T cells and immune effector cells within affected organs, most frequently the lungs. ...Exosomes are extracellular vesicles conveying intercellular communication with possible diagnostic and therapeutic applications. Objectives We aimed to provide an understanding of the proinflammatory role of bronchoalveolar lavage fluid (BALF) exosomes in patients with sarcoidosis and to find candidates for disease biomarkers. Methods We performed a mass spectrometric proteomics characterization of BALF exosomes from 15 patients with sarcoidosis and 5 healthy control subjects and verified the most interesting results with flow cytometry, ELISA, and Western blot analyses in an additional 39 patients and 22 control subjects. Results More than 690 proteins were identified in the BALF exosomes, several of which displayed significant upregulation in patients, including inflammation-associated proteins, such as leukotriene A4 hydrolase. Most of the complement-activating factors were upregulated, whereas the complement regulator CD55 was seen less in patients compared with healthy control subjects. In addition, for the first time, we detected vitamin D–binding protein in BALF exosomes, which was more abundant in patients. To evaluate exosome-associated vitamin D–binding protein as a biomarker for sarcoidosis, we investigated plasma exosomes from 23 patients and 11 healthy control subjects and found significantly higher expression in patients. Conclusion Together, these data contribute to understanding the role of exosomes in lung disease and provide suggestions for highly warranted sarcoidosis biomarkers. Furthermore, the validation of an exosome-associated biomarker in the blood of patients provides novel, and less invasive, opportunities for disease diagnosis.
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