Urinary proteome of dogs with kidney injury during babesiosis

Abstract This study aimed to identify proteins found in the urine of dogs with renal dysfunction leading to acute injury during the natural course of babesiosis (n=10) and to compare them with proteins of a control group (n=10) to reveal any potential biomarkers of renal damage. Pooled urine samples of both groups were separated by 2D electrophoresis (two dimensional electrophoresis), followed by the identification of all proteins using MALDI-TOF mass spectrometry (matrix assisted laser desorption ionization-time of flight). In total, 176 proteins were identified in the urine samples from healthy dogs, and 403 proteins were identified in the urine samples from dogs with babesiosis. Of the 176 proteins, 146 were assigned exclusively to healthy dogs, and 373 of the 403 proteins were assigned exclusively to dogs with babesiosis; 30 proteins were common to both groups. Characteristic analysis of the 373 proteins found in dogs with babesiosis led to the isolation of 8 proteins associated with 10 metabolic pathways that were attributed to immune and inflammatory response development. Furthermore, it was hypothesized that the epithelial-mesenchymal transition might play an important role in mechanisms underlying pathological renal tissue changes during babesiosis, as indicated by a causal relationship network built by combining 5 of the 10 selected metabolic pathways and 4 of the 8 proteins associated with these pathways. These included cadherins, gonadotropin releasing hormone receptors, inflammatory responses mediated by chemokine and cytokine signalling pathways, integrins, interleukin and TGF-β (transforming growth factor β) pathways. These pathways were linked by interleukin-13, bone morphogenetic protein 7, α2(1) collagen, and FER tyrosine kinase, which are potential damage biomarkers during babesiosis in dogs that might be assigned to early renal injury. Keywords: Acute kidney injury; Babesiosis; Dog; Proteomics; Urine