URINE PROTEOME FROM HEALTHY DOGS, CATS, HORSES AND COWS

Background: Data on the urinary proteome of domestic animals are limited, as a consequence the study of urinary proteome of healthy domestic animals is the first step to discover new biomarkers of nephropathy. Objective: The study of the urine proteome from healthy dogs, cats, horses and cows. Methods: Urine samples were collected from clinically healthy dogs (15), cats (10), horses (37) and cows (10). For all samples, UP/C was calculated and SDS-PAGE with silver staining was performed. Results: All samples had UP/C lower than 0.2. After SDS-PAGE, all samples showed many bands, which were undetectable by routine methods. In dogs were found 15-19 bands, in cats 17-20, in horses 13-15 and in cows 15-18. On the basis of the apparent molecular weight (MW) reported in kDa and comparing with human urine proteome, we tried an identification of the most represented proteins: P90 (Tamm-Horsfall), P76 (transferrin), P64 (albumin) P54 (immunoglobulin heavy chain) P27 (immunoglobulin light chain) and P14 (lysozyme). All samples presented putative albumin, transferrin, IG heavy and light chains; Tamm-Horsfall was clearly evident in dogs, horses and cats. Dogs and cows presented proteins mainly at MW lower than albumin, cats presented proteins mainly at MW higher than albumin, while horses presented proteins at both high and low MW. Conclusion: SDS-PAGE/silver staining is a very sensitive method to detect low abundance proteins in urine of healthy domestic animals, allowing the identification of different species-specific electrophoretic profiles. Work is in progress to confirm the identity of the different proteins.