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Sample Preparation for Mass-spectrometry-based Proteomics Analysis of Ocular Microvessels
Published on: February 22, 2019
Tear Film Proteome of Healthy Domestic Cats
Jéssica Fontes Veloso1, Paula Elisa Brandão Guedes2, Luciana Carvalho Lacerda2
1Multidisciplinary Campus of Barra, Federal University of Western Bahia, Av. 23 de Agosto, 873, Assunção, Barra, Bahia, Brazil.
Insights
This study identified 16 proteins in domestic cat tear film, including novel proteins, to understand feline ocular surface health. The findings advance knowledge of the feline tear proteome and ocular surface homeostasis.
Area of Science:
- Veterinary Medicine
- Proteomics
- Ophthalmology
Background:
- The tear film proteome is crucial for ocular surface health and homeostasis.
- Limited research exists on the specific protein composition of domestic cat tear film.
Purpose of the Study:
- To comprehensively investigate and identify proteins present in the tear film of healthy domestic cats.
- To establish a baseline understanding of the feline tear proteome for future comparative studies.
Main Methods:
- Tear samples collected using Schirmer tear test strips from twelve healthy cats.
- Protein analysis via two-dimensional polyacrylamide gel electrophoresis and liquid chromatography-mass spectrometry.
- Spectra analysis and comparison with the Swiss-Prot database for protein identification.
Main Results:
- Identification of 16 unique proteins in the feline tear film.
- Confirmation of known proteins like lactotransferrin and serum albumin.
- Discovery of novel proteins, including cyclin-dependent protein kinase and apelin receptor, in feline tears.
Conclusions:
- The identified proteins play vital roles in defense and maintaining feline ocular surface homeostasis.
- This study provides the first in-depth report on the domestic cat tear film proteome.
- Findings contribute to a deeper understanding of feline ocular health and disease mechanisms.
Abstract:
The aim of this study was to investigate the proteins found in tear film of healthy domestic cats. Schirmer tear test strips were used to collect tear samples of twelve healthy cats, which were mixed, centrifuged, and placed in a single 1.5 mL microtube that was frozen at -20°C, until analysis by two-dimensional polyacrylamide gel and mass spectrometry associated with high-performance liquid chromatography. The resulting spectra were analyzed and compared with the Swiss-Prot search tool. Forty peptides were detected in the analyzed protein fragments of 90 spots, with 16 proteins identified. Of these, the authors confirmed what has been already found in other studies: lactotransferrin, serum albumin, allergenic lipocalins, and neutrophil gelatinase-associated lipocalin. Others were considered novel in tear film samples of all species: cyclin-dependent protein kinase, serine/arginine repetitive matrix protein, apelin receptor, secretory protein related to C1q/TNF, Wee1, α-1,4 glucan phosphorylase, and WD repeat domain 1. The network was divided into 11 clusters, and a biological function was assigned. Most of the proteins have functions in the defense and maintenance of feline ocular surface homeostasis. Serum albumin is a bottleneck protein, with a high betweenness value. This paper is a pioneer in reporting, in-depth, the tear film proteome of domestic cats.
