Larisa Kovacevic1, Hong Lu2, Joseph A Caruso3, Yegappan Lakshmanan2. 1. Department of Pediatric Urology, Children's Hospital of Michigan, Detroit, MI. Electronic address: lkovacev@dmc.org. 2. Department of Pediatric Urology, Children's Hospital of Michigan, Detroit, MI. 3. Institute of Environmental Health Sciences, Wayne State University, Detroit, MI.
Abstract
OBJECTIVE: To investigate whether inflammation, oxidation, and tubular injury are present in children with stones (RS) compared with healthy controls (HC) by measuring urinary proteins involved in these processes. METHODS: Quantitative proteomic comparison of pooled urine from RS (N = 30, 24 females, mean age 12.95 ± 4.03 years) versus age- and gender-matched HC (N = 30), using liquid chromatography-mass spectrometry. Relative protein abundance was estimated using spectral counting. Proteins of interest were selected using the following criteria: (1) ≥5 spectral counts; (2) ≥2-fold difference in spectral counts; and (3) P-value ≤.05 for Fisher's exact test. RESULTS: Of the 1813 proteins identified, 230 met the above criteria, with 163 proteins upregulated in the RS group and 67 upregulated in HC. Functional analysis revealed 19 inflammatory proteins, 5 proteins involved in oxidative stress, and 5 involved in tubular injury. Of those proteins, NADPH-oxidase, a major source of reactive oxygen species, was only found in the RS group, whereas glutathione S-transferase A2, an important antioxidant enzyme, was more abundant in controls. ELISA analysis confirmed statistically significant differences in the urinary excretion of retinol-binding protein 4, a marker of proximal tubular dysfunction, between stone patients with hypercalciuria and controls. CONCLUSION: We provide proteomic evidence of oxidative stress, inflammation, and tubular injury in children with renal stones. We speculate that inflammation and changes in the oxidant-antioxidant balance may cause tubular damage in these patients. Targeting these proteins may have therapeutic benefits.
OBJECTIVE: To investigate whether inflammation, oxidation, and tubular injury are present in children with stones (RS) compared with healthy controls (HC) by measuring urinary proteins involved in these processes. METHODS: Quantitative proteomic comparison of pooled urine from RS (N = 30, 24 females, mean age 12.95 ± 4.03 years) versus age- and gender-matched HC (N = 30), using liquid chromatography-mass spectrometry. Relative protein abundance was estimated using spectral counting. Proteins of interest were selected using the following criteria: (1) ≥5 spectral counts; (2) ≥2-fold difference in spectral counts; and (3) P-value ≤.05 for Fisher's exact test. RESULTS: Of the 1813 proteins identified, 230 met the above criteria, with 163 proteins upregulated in the RS group and 67 upregulated in HC. Functional analysis revealed 19 inflammatory proteins, 5 proteins involved in oxidative stress, and 5 involved in tubular injury. Of those proteins, NADPH-oxidase, a major source of reactive oxygen species, was only found in the RS group, whereas glutathione S-transferase A2, an important antioxidant enzyme, was more abundant in controls. ELISA analysis confirmed statistically significant differences in the urinary excretion of retinol-binding protein 4, a marker of proximal tubular dysfunction, between stone patients with hypercalciuria and controls. CONCLUSION: We provide proteomic evidence of oxidative stress, inflammation, and tubular injury in children with renal stones. We speculate that inflammation and changes in the oxidant-antioxidant balance may cause tubular damage in these patients. Targeting these proteins may have therapeutic benefits.
Authors: Karlie A Neilson; Naveid A Ali; Sridevi Muralidharan; Mehdi Mirzaei; Michael Mariani; Gariné Assadourian; Albert Lee; Steven C van Sluyter; Paul A Haynes Journal: Proteomics Date: 2011-01-17 Impact factor: 3.984
Authors: Przemyslaw Sikora; Sara Glatz; Bodo B Beck; Ludwig Stapenhorst; Malgorzata Zajaczkowska; Albrecht Hesse; Bernd Hoppe Journal: Pediatr Nephrol Date: 2003-08-13 Impact factor: 3.714
Authors: Larisa Kovacevic; Joseph A Caruso; Hong Lu; Natalija Kovacevic; Yegappan Lakshmanan; Nicholas J Carruthers; David S Goldfarb Journal: Int Urol Nephrol Date: 2018-12-05 Impact factor: 2.370
Authors: Ellen R Brooks; Bernd Hoppe; Dawn S Milliner; Eduardo Salido; John Rim; Leah M Krevitt; Julie B Olson; Heather E Price; Gulsah Vural; Craig B Langman Journal: Am J Nephrol Date: 2016-05-03 Impact factor: 3.754