Proteomic signature of circulating extracellular vesicles in dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) remains a major cause of heart failure and carries a poor prognosis despite important advances in recent years. Better disease characterization using novel molecular techniques is needed to refine its progression. This study explored the proteomic signature of plasma-derived extracellular vesicles (EVs) obtained from DCM patients and healthy controls using size-exclusion chromatography (SEC). EV-enriched fractions were analyzed by liquid chromatography-mass spectrometry (LC-MS/MS). Raw data obtained from LC-MS/MS were analyzed against the Uniprot human database using MaxQuant software. Additional analyses using Perseus software were based on the Intensity-Based Absolute Quantification (iBAQ) values from MaxQuant analyses. A total of 90.07 ± 21 proteins (227 different proteins) in the DCM group and 96.52 ± 17.91 proteins (183 different proteins) in the control group were identified. A total of 176 proteins (74.6%) were shared by controls and DCM patients, whereas 51 proteins were exclusive for the DCM group and 7 proteins were exclusive for the control group. Fibrinogen (α, β and γ chain), serotransferrin, α-1-antitrypsin, and a variety of apolipoprotein family members (C-I, C-III, D, H or β-2-glycoprotein, and J or clusterin) were clustered in SEC-EVs derived from DCM patients relative to controls (p < 0.05). Regarding Gene Ontology analysis, response to stress and protein activation-related proteins were enriched in DCM-EVs compared with controls. Thus, the present study reports the distinct proteomic signature of circulating DCM-EVs compared with control-EVs. Furthermore, we confirm that SEC obtains highly purified EV fractions from peripheral blood samples for subsequent use in determining disease-specific proteomic signatures.