Introduction

Idiopathic dilated cardiomyopathy (iDCM) is the second most common cardiac disease in dogs with an unknown aetiology and poor prognosis. Since it is considered that the blood proteome reflects the systemic changes that happen upon organ dysfunction, large-scale proteomic studies can contribute to the understanding of pathologic mechanisms involved in canine iDCM.

Objectives

The goal was to examine the differences between serum proteome of dogs with iDCM and healthy dogs using tandem mass tags (TMT) quantitative proteomics approach.

Methods

Serum was collected from 8 dogs with iDCM and 8 healthy dogs. Serum samples were depleted from albumin, labeled with different TMT reagents and analysed by Orbitrap Elite mass spectrometer. Bioinformatics quantitative analysis of relative protein abundance was performed using Proteome Discoverer and gene ontology analysis using the Cytoscape software.

Results

There were 134 proteins identified and quantified in serum samples. The average protein abundance fold change (iDCM/healthy ratio) ranged from 0.5–2. The abundance of 13 proteins was significantly different between iDCM and healthy serum (p<0.05) with the fold changes of 1.2 or 0.8. Biological functions of differentially abundant proteins indicate the involvement of various pathways in canine iDCM, including lipoprotein particle dynamics, complement activation and regulation of systemic arterial blood pressure.

Conclusions

This study shows that the differences in serum proteome between dogs with iDCM and healthy dogs can be detected with label-based LC-MS/MS method. This proteomic approach in research of canine iDCM can aid in better understanding of its pathophysiology and potentially lead to the discovery of biomarkers relevant for the disease.