engleski

Analysis of proteomic changes during myxomatrous degenerative changes of mitral valve in dogs

Objective: Myxomatous mitral valve disease (MMVD) is the most common heart disease and the most frequent cause of congestive heart failure in canine species. The MMVD pathology is almost identical in humans and in dogs ; the murmur of mitral valve gurgitation appears years before the clinical onset of heart failure. According to the American College of Veterinary Internal Medicine staging system, dogs with diagnosed MMVD may be asymptomatic with no/mild (stage B1) or more advanced (stage B2) mitral valve regurgitation as well as symptomatic, with clinical signs of heart failure (stage C). The study compared quantitative proteome profiles in serum of healthy and dogs with diagnosed MMVD at different stages. The ultimate goal was identification of potential proteomic biomarkers for early diagnosis of MMVD and detection of progression from stage B1 to B2. Methods: Serum samples from 50 dogs were collected at the time of initial diagnosis and before any treatment. According to findings on clinical examination and ultrasound imaging, four groups were formed: healthy dogs (N= 12), MMVD stage B1 (N=13), stage B2 (N=12) and stage C (N=13). The samples were processed using shotgun, TMT-based quantitative workflow. Top8 data-dependent acquisition was performed on the Q Exactive Plus mass spectrometer (Thermo Fisher Scientific, Bremen, Germany) after peptide separation on the Ultimate 3000 RSLCnano system (Dionex, Germering, Germany). Protein identification and relative quantification were performed using Proteome Discoverer software (version 2.3., Thermo Fisher Scientific) with SEQUEST algorithm implemented and database search against Canis lupus FASTA files. Statistical and bioinformatics analysis were done using R and PANTHER classification tool. Results: Altogether, 318 proteins were quantified, 33 proteins had statistically different abundance between four experimental groups. The post-hoc analysis identified 15 proteins that had significantly different abundances between control group and MMVD stage B1, approximately half were down regulated (N=8) and half up regulated (N=7) in MMVD stage B1. In diseased dogs (stage B1) transferrin receptor and xaa-Pro dipeptidase proteins, classified by gene ontology as metalloproteases, and gelsolin protein, a non-motor actin binding protein involved in FAS signalling pathway were down regulated in dogs with stage B1 of MMVD. In addition, blood coagulation protein (vitamin K- dependent protein S), glycoproteins (haptoglobin- like, glycoprotein 80 and hemopexin) and several binding proteins (C4b-binding protein alpha chain and retinol-binding protein) were up regulated. In comparison to stage B1, three proteins were down regulated (C-C motif chemokine 14-like, complement C3-like and haptoglobin-like), while complement component C7 isoform X1 was up regulated in stage B2. Conclusion: The quantitative proteome analysis enabled discovery of potential serum biomarkers for early diagnosis of MMVD (stage B1) and differentiation of MMVD stages B1 and B2. Conclusion: The quantitative proteome analysis enabled discovery of potential serum biomarkers for early diagnosis of MMVD (stage B1) and differentiation of MMVD stages B1 and B2.

myxomatrous degenerative changes, mitral valves, dogs, proteomics

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