Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy.
Department of Veterinary Medical Sciences, University of Bologna, Ozzano, Bologna, Italy..
J Proteomics. 2020 Jun 30;222:103795. doi: 10.1016/j.jprot.2020.103795. Epub 2020 Apr 23.
Chronic kidney disease (CKD) is a progressive and irreversible disease. Although urine is an ideal biological sample for proteomics and metabolomics studies, sensitive and specific biomarkers are currently lacking in dogs. This study characterised dog urine proteome and metabolome aiming to identify and possibly quantify putative biomarkers of CKD in dogs. Twenty-two healthy dogs and 28 dogs with spontaneous CKD were selected and urine samples were collected. Urinary proteome was separated by SDS-PAGE and analysed by mass spectrometry, while urinary metabolome was analysed in protein-depleted samples by 1D H NMR spectra. The most abundant proteins in urine samples from healthy dogs were uromodulin, albumin and, in entire male dogs, arginine esterase. In urine samples from CKD dogs, the concentrations of uromodulin and albumin were significantly lower and higher, respectively, than in healthy dogs. In addition, these samples were characterised by a more complex protein pattern indicating mixed glomerular (protein bands ≥65 kDa) and tubular (protein bands <65 kDa) proteinuria. Urine spectra acquired by NMR allowed the identification of 86 metabolites in healthy dogs, belonging to 49 different pathways mainly involved in amino acid metabolism, purine and aminoacyl-tRNA biosynthesis or tricarboxylic acid cycle. Seventeen metabolites showed significantly different concentrations when comparing healthy and CKD dogs. In particular, carnosine, trigonelline, and cis-aconitate, might be suggested as putative biomarkers of CKD in dogs. SIGNIFICANCE: Urine is an ideal biological sample, however few proteomics and metabolomics studies investigated this fluid in dogs and in the context of CKD (chronic kidney disease). In this research, applying a multi-omics approach, new insights were gained regarding the molecular changes triggered by this disease in canine urinary proteome and metabolome. In particular, the involvement of the tubular component was highlighted, suggesting uromodulin, trigonelline and carnosine as possible biomarkers of CKD in dogs.
慢性肾病（CKD）是一种进行性和不可逆的疾病。尽管尿液是蛋白质组学和代谢组学研究的理想生物样本，但目前犬类缺乏敏感和特异性的生物标志物。本研究旨在对犬尿液蛋白质组和代谢组进行特征分析，以鉴定和可能量化犬 CKD 的潜在生物标志物。选择了 22 只健康犬和 28 只自发性 CKD 犬，并采集尿液样本。通过 SDS-PAGE 分离尿液蛋白质组，并通过质谱进行分析，而蛋白质组耗尽样本中的尿液代谢组通过 1D H NMR 谱进行分析。健康犬尿液样本中最丰富的蛋白质是尿调蛋白、白蛋白，在所有雄性犬中，还有精氨酸酯酶。在 CKD 犬的尿液样本中，尿调蛋白和白蛋白的浓度分别显著降低和升高。此外，这些样本的蛋白质图谱更复杂，表明混合性肾小球（蛋白带≥65 kDa）和肾小管（蛋白带<65 kDa）蛋白尿。通过 NMR 获得的尿液光谱可鉴定出 86 种健康犬的代谢物，属于 49 种不同的代谢途径，主要涉及氨基酸代谢、嘌呤和氨酰-tRNA 生物合成或三羧酸循环。17 种代谢物在比较健康犬和 CKD 犬时显示出明显不同的浓度。特别是，肌肽、瓜氨酸和顺乌头酸可能被建议作为犬 CKD 的潜在生物标志物。意义：尿液是一种理想的生物样本，然而，很少有蛋白质组学和代谢组学研究在犬类和 CKD 背景下对这种液体进行研究。在这项研究中，应用多组学方法，我们对犬尿液蛋白质组和代谢组中由这种疾病引发的分子变化有了新的认识。特别是，肾小管成分的参与得到了强调，提示尿调蛋白、瓜氨酸和肌肽可能是犬 CKD 的潜在生物标志物。
