Urine Proteomic Analysis of Differences Between Patients With Hyperthyroidism Before and After Carbimazole Treatment

Abstract

Abstract Background: Hyperthyroidism, characterised by increased circulating thyroid hormone (TH) levels, alters the body’s metabolic and systemic haemodynamic balance and directly influences renal function However, the underlying mechanisms and metabolic implications of these changes are not well understood. Objective: In the present study we aimed to study the changes occurring in the urinary proteome of patients with hyperthyroidism before and after treatment. The levels of the excreted proteins in the urine were studied using an untargeted 2D DIGE MALDI TOF proteomic approach with network analysis. Methods: The study included 9 age matched patients with mean age 38.6 ± 12.1 years with newly diagnosed hyperthyroidism. The patients were evaluated at baseline and after receiving treatment with carbimazole. Urine samples were obtained from the same patient at baseline (hyperthyroid state) with serum FT4 levels of 35.4 + 9.9 pmol/L and TSH 0.014 + 0.014 mIU/L (mean + SD), and post treatment with anti-thyroid drugs (euthyroid state) with levels of FT4 17.0 + 2.8 pmol/L and TSH 0.6 + 0.5 mIU/L (mean + SD). Results: Alterations in the abundance of urinary proteins, analyzed by Progenesis software, revealed statistically significant differential abundance in a total of 40 spots corresponding to 33 proteins, 26 up and 7 down (≥1.5-fold change, ANOVA, p ≤ 0.05). The proteins identified in the study are known to regulate processes related to cellular metabolism, transport, acute phase response. The urinary proteins upregulated with hyperthyroidism included serotransferrin, transthyretin, serum albumin, ceruloplasmin, α1B glycoprotein, syntenin-1, nesprin, and glutamilnyl peptide cyclotransferase while the 3 notable down regulated proteins were plasma kallikrein, protein glutamine gamma-glutamyl transferase and serpin B3. Bioinformatic analysis using Ingenuity Pathway Analysis (IPA) identified dysregulation of pathways related to cellular compromise, inflammatory response, cellular assembly and organization and identified the involvement of the APP and AKT signaling pathways via their interactions with interleukins as the central nodes. Conclusion: The urine proteomic profiling between the hyperthyroid and euthyroid states demonstrates alteration in the protein levels involved in acute phase response and in maintaining an individual’s haemodynamic state.