Proteome Analysis of Plasma Exosomes in a Mouse Model of Dilated Cardiomyopathy (4C30 strain)

Abstract

AimThe role of exosomes is focused on in various diseases. In this study, I examined protein profiles in plasma exosomes of a mouse model of dilated cardiomyopathy (4C30 strain) to discover possible protein biomarkers for cardiomyopathy in plasma exosomes.MethodsPlasma samples were collected from 15‐week‐old male mice of cardiomyopathic 4C30 and normal C57BL/6NCr mice (five mice/strain). Plasma exosomes were collected from 1 mL of plasma, pooled from the five mice (0.2 mL/mice) in each strain using Exosome extraction kit for plasma (Invitrogen). Exosomal proteins were solubilized, cleaned up, reduced and alkylated. Approximately 50 µg of exosomal proteins were separated by isoelectric focusing and then SDS‐PAGE. After SyproRuby staining, two‐dimension electropherograms of exosomal proteins were compared between two strains. Some protein spots were punched out and their protein identities were determined by mass spectrometry.Results and DiscussionOnly a few differences were found in exosomal proteins between strains. Of proteins preferentially present in the 4C30 exosome, three spots were picked up and examined by mass spectrometry. One of them was fibrinogen gamma chain (FGG), which was thought to be a contaminant from plasma soluble components. The other two spots were under examination. Our results suggest that cardiomyopathy induces only a subtle change in exosomal proteins. This work was supported by a grant from the Ministry of Health, Labour and Welfare of Japan.