Proteomic analysis of tear film composition in diabetic dogs

Abstract

AbstractPurposeDiabetes mellitus is becoming an increasing concern in veterinary practice and research. Not treated, it can lead to serious systemic complications and even animal death. The most common form of diabetes in dogs resembles type 1 diabetes in humans. Tear film is easily accessible fluid that can be collected during routine veterinary visit. Based on research conducted in humans, we propose that diabetes can reflect on tear film proteomic composition.MethodsThe study was conducted on 49 dogs. Enrollment was restricted to clinically stable diabetic dogs. Nineteen healthy age‐ and sex‐matched dogs were included as a control group. Tear film was collected with Schirmer strips from the diabetes and sex‐ and age‐matched control group. Two‐dimensional electrophoresis was performed followed by MALDI‐TOF mass spectrometry identification of differential proteins. Quantitative analysis of the differentiating electrophoretic spots was done with 2Delta software. Metabolic pathways associated with those proteins were identified with Panther GO software.ResultsNine out of a total 489 proteins detected on all of the gels were identified as significantly differentially expressed (p ≤ 0.05) in tear film samples collected from diabetic patients. Eight of the nine proteins were assigned to downregulated, namely Phosphatydylinositol‐4 kinase, Pro‐melanin concentrating hormone, Flotillin‐1, Protein mono‐adp ribosyltransferase, ATP‐dependent RNA helicase, GRIP and coiled coil domain containing protein 2, Tetratricopeptide repeat protein 36, Myosin light chain 6B and Prelamin A/C. One of the nine proteins (SRC kinase signalling inhibitor 1) was assigned to upregulated.ConclusionsTear film obtained from dogs with diabetes differs from the healthy controls. Those findings correspond with research conducted in humans, and can add value to our understanding about the course of the disease in dogs. Also, dogs serve well as an animal model of various human diseases.