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Tater A, Gupta A, Upadhyay G, Deshpande A, Date R, Tamboli IY. In vitro assays for characterization of distinct multiple catalytic activities of thyroid peroxidase using LC-MS/MS. Curr Res Toxicol 2021; 2:19-29. [PMID: 34345847 PMCID: PMC8320612 DOI: 10.1016/j.crtox.2021.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/30/2020] [Accepted: 01/05/2021] [Indexed: 11/30/2022] Open
Abstract
Multiple reactions catalyzed by thyroid peroxidase (TPO) were monitored by a battery of unique in vitro assays. Monoiodination and diiodination of L-Tyr to MIT and DIT was examined in a single assay. MIT to DIT and T3 to T4 monoiodination reactions were monitored separately. DIT to T4 conversion assay was used to study coupling of iodotyrosine phenolic rings. Distinct Km, Vmax, Kcat and Kcat/ Km values for each of the TPO catalysed reaction are presented. Differential response of 5 known inhibitors with specific TPO reactions was studied.
A diverse set of environmental contaminants have raised a concern about their potential adverse effects on endocrine signaling. Robust and widely accepted battery of in vitro assays is available to assess the disruption of androgenic and estrogenic pathways. However, such definitive systems to investigate effects on the disruption of thyroid pathways by the xenobiotics are not yet well established. One of the major “Molecular Initiating Events” (MIEs) in thyroid disruption involves targeting of thyroid peroxidase (TPO), a key enzyme involved in thyroid hormone synthesis. TPO catalyzes mono- and diiodination of L-Tyrosine (L-Tyr) to generate 3-Iodo-l-tyrosine (MIT) and 3,5-Diiodo-l-tyrosine (DIT), respectively, followed by the coupling of iodinated tyrosine rings to generate thyroid hormones, 3,3’5-Triiodo-l-thyronine (T3) and Levothyroxine (T4). We sought to develop a robust, sensitive, and rapid in vitro assay systems to evaluate the effects of test chemicals on the multiple catalytic activities of thyroid peroxidase. Simple in vitro assays were designed to study TPO mediated distinct reactions using a single LC-MS/MS method. Herein, we describe a battery of assays to investigate the iodination of L-Tyr to MIT and DIT, MIT to DIT as well as, T3 to T4 catalyzed by rat thyroid TPO. Importantly, two sequential reactions involving mono- and diiodination of L-Tyr could be analyzed in a single assay. The assay that monitors in vitro conversion of DIT to T4 was developed to study the coupling of tyrosine rings. Enzyme kinetics studies revealed distinct characteristics of multiple reactions catalyzed by TPO. Further, the known TPO inhibitors were used to assess their potency towards individual TPO substrates and reactions. The resultant half maximum inhibitory concentration (IC50) values highlighted differential targeting of TPO catalyzed reactions by the same inhibitor. Overall results underscore the need to develop more nuanced approaches that account for distinct multiple catalytic activities of TPO.
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Affiliation(s)
- Abhishek Tater
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
| | - Aditi Gupta
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
| | - Gopal Upadhyay
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
| | - Abhay Deshpande
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
| | - Rahul Date
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
| | - Irfan Y Tamboli
- Jai Research Foundation, N. H. 48, Near Daman-Ganga bridge, Valvada 396105, India
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Noyes PD, Friedman KP, Browne P, Haselman JT, Gilbert ME, Hornung MW, Barone S, Crofton KM, Laws SC, Stoker TE, Simmons SO, Tietge JE, Degitz SJ. Evaluating Chemicals for Thyroid Disruption: Opportunities and Challenges with in Vitro Testing and Adverse Outcome Pathway Approaches. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:95001. [PMID: 31487205 PMCID: PMC6791490 DOI: 10.1289/ehp5297] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 07/01/2019] [Accepted: 08/13/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Extensive clinical and experimental research documents the potential for chemical disruption of thyroid hormone (TH) signaling through multiple molecular targets. Perturbation of TH signaling can lead to abnormal brain development, cognitive impairments, and other adverse outcomes in humans and wildlife. To increase chemical safety screening efficiency and reduce vertebrate animal testing, in vitro assays that identify chemical interactions with molecular targets of the thyroid system have been developed and implemented. OBJECTIVES We present an adverse outcome pathway (AOP) network to link data derived from in vitro assays that measure chemical interactions with thyroid molecular targets to downstream events and adverse outcomes traditionally derived from in vivo testing. We examine the role of new in vitro technologies, in the context of the AOP network, in facilitating consideration of several important regulatory and biological challenges in characterizing chemicals that exert effects through a thyroid mechanism. DISCUSSION There is a substantial body of knowledge describing chemical effects on molecular and physiological regulation of TH signaling and associated adverse outcomes. Until recently, few alternative nonanimal assays were available to interrogate chemical effects on TH signaling. With the development of these new tools, screening large libraries of chemicals for interactions with molecular targets of the thyroid is now possible. Measuring early chemical interactions with targets in the thyroid pathway provides a means of linking adverse outcomes, which may be influenced by many biological processes, to a thyroid mechanism. However, the use of in vitro assays beyond chemical screening is complicated by continuing limits in our knowledge of TH signaling in important life stages and tissues, such as during fetal brain development. Nonetheless, the thyroid AOP network provides an ideal tool for defining causal linkages of a chemical exerting thyroid-dependent effects and identifying research needs to quantify these effects in support of regulatory decision making. https://doi.org/10.1289/EHP5297.
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Affiliation(s)
- Pamela D Noyes
- National Center for Environmental Assessment, Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Washington, DC, USA
| | - Katie Paul Friedman
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Patience Browne
- Environment Health and Safety Division, Environment Directorate, Organisation for Economic Co-operation and Development (OECD), Paris, France
| | - Jonathan T Haselman
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Mary E Gilbert
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Michael W Hornung
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Stan Barone
- Office of Pollution Prevention and Toxics, Office of Chemical Safety and Pollution Prevention, U.S. EPA, Washington, DC, USA
| | - Kevin M Crofton
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Susan C Laws
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Tammy E Stoker
- Toxicity Assessment Division, NHEERL, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Steven O Simmons
- National Center for Computational Toxicology, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Joseph E Tietge
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
| | - Sigmund J Degitz
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory (NHEERL), ORD, U.S. EPA, Duluth, Minnesota, USA
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Serrano J, Kolanczyk RC, Tapper MA, Lahren T, Dongari N, Hammermeister DE, Kosian PA, Schmieder PK, Sheedy BR, Challis K, Kubátová A. Characterization and analysis of estrogenic cyclic phenone metabolites produced in vitro by rainbow trout liver slices using GC-MS, LC-MS and LC-TOF-MS. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1126-1127:121717. [PMID: 31437775 DOI: 10.1016/j.jchromb.2019.121717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/18/2019] [Accepted: 07/12/2019] [Indexed: 11/25/2022]
Abstract
Cyclic phenones are chemicals of interest to the USEPA and international organizations due to their potential for endocrine disruption to aquatic and terrestrial species. The metabolic conversion of cyclic phenones by liver hepatocytes and the structure of main metabolites yielded have not been assessed in fish species. As part of a larger project, in this study we investigated the structure of metabolites produced in vitro by rainbow trout (rt) liver slices after exposure to the model cyclic phenones benzophenone (DPK), cyclobutyl phenyl ketone (CBP) and cyclohexyl phenyl ketone (CPK). While only one distinct metabolite was detected for DPK and CBP (benzhydrol and CBPOH, respectively), CPK yielded nine positional isomers (M1-M9) as products. In absence of standards, improved inference of CPK metabolites tentative structures was achieved by combining GC-MS with and without derivatization, LC with tandem MS, LC with high resolution time of flight (TOF) MS and LC fractionation data with CPK phase II conjugative metabolism information. Data supported that CPK is metabolized by phase I oxidation of the cyclohexyl ring and not the phenyl group as predicted by metabolism simulators. CPK metabolites M1 and M2 (MW 186), were proposed to be cyclohexenyl-derivatives. Also, M6-M9 were proposed to be hydroxylated metabolites (MW 204), with the potential for undergoing phase II conjugative metabolism to glucuronides and sulfates. Finally, M3, M4 and M5 were proposed as cyclohexanone-derivatives of CPK (MW 202), resulting from the limited redox-interconversion of their hydroxylated pairs M8, M6 and M7, respectively. Assessment of metabolite role in biological responses associated with endocrine disruption will advance the development of methods for species extrapolation and the understanding of differential sensitivity of species to chemical exposure.
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Affiliation(s)
- Jose Serrano
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA.
| | - Richard C Kolanczyk
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Mark A Tapper
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Tylor Lahren
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Nagaraju Dongari
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND, USA
| | - Dean E Hammermeister
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Patricia A Kosian
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Patricia K Schmieder
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Barbara R Sheedy
- USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Katie Challis
- Student Services Contractor, Mid-Continent Ecology Division, 6201 Congdon Boulevard, Duluth, MN, USA
| | - Alena Kubátová
- University of North Dakota, Department of Chemistry, 151 Cornell Street Stop 9024, Grand Forks, ND, USA
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Serrano J, Tapper MA, Kolanczyk RC, Sheedy BR, Lahren T, Hammermeister DE, Denny JS, Hornung MW, Kubátová A, Kosian PA, Voelker J, Schmieder PK. Metabolism of cyclic phenones in rainbow trout in vitro assays. Xenobiotica 2019; 50:192-208. [DOI: 10.1080/00498254.2019.1596331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jose Serrano
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Mark A. Tapper
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Richard C. Kolanczyk
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Barbara R. Sheedy
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Tylor Lahren
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Dean E. Hammermeister
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Jeffrey S. Denny
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Michael W. Hornung
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Alena Kubátová
- Department of Chemistry, University of North Dakota, Grand Forks, ND, USA
| | - Patricia A. Kosian
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
| | - Jessica Voelker
- Mid-Continent Ecology Division, Student Services Contractor, Duluth, MN, USA
| | - Patricia K. Schmieder
- Mid-Continent Ecology Division, USEPA, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Duluth, MN, USA
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Nagasawa K, Tanizaki Y, Okui T, Watarai A, Ueda S, Kato T. Significant modulation of the hepatic proteome induced by exposure to low temperature in Xenopus laevis. Biol Open 2013; 2:1057-69. [PMID: 24167716 PMCID: PMC3798189 DOI: 10.1242/bio.20136106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 07/22/2013] [Indexed: 01/24/2023] Open
Abstract
The African clawed frog, Xenopus laevis, is an ectothermic vertebrate that can survive at low environmental temperatures. To gain insight into the molecular events induced by low body temperature, liver proteins were evaluated at the standard laboratory rearing temperature (22°C, control) and a low environmental temperature (5°C, cold exposure). Using nano-flow liquid chromatography coupled with tandem mass spectrometry, we identified 58 proteins that differed in abundance. A subsequent Gene Ontology analysis revealed that the tyrosine and phenylalanine catabolic processes were modulated by cold exposure, which resulted in decreases in hepatic tyrosine and phenylalanine, respectively. Similarly, levels of pyruvate kinase and enolase, which are involved in glycolysis and glycogen synthesis, were also decreased, whereas levels of glycogen phosphorylase, which participates in glycogenolysis, were increased. Therefore, we measured metabolites in the respective pathways and found that levels of hepatic glycogen and glucose were decreased. Although the liver was under oxidative stress because of iron accumulation caused by hepatic erythrocyte destruction, the hepatic NADPH/NADP ratio was not changed. Thus, glycogen is probably utilized mainly for NADPH supply rather than for energy or glucose production. In conclusion, X. laevis responds to low body temperature by modulating its hepatic proteome, which results in altered carbohydrate metabolism.
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Affiliation(s)
- Kazumichi Nagasawa
- Department of Integrative Bioscience and Biomedical Engineering, Graduate School of Advanced Science and Engineering, Center for Advanced Life and Medical Science, Waseda University , TWIns Building, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480 , Japan
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Martyniuk CJ, Alvarez S, Denslow ND. DIGE and iTRAQ as biomarker discovery tools in aquatic toxicology. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 76:3-10. [PMID: 22056798 PMCID: PMC4238381 DOI: 10.1016/j.ecoenv.2011.09.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/27/2011] [Accepted: 09/28/2011] [Indexed: 05/31/2023]
Abstract
Molecular approaches in ecotoxicology have greatly enhanced mechanistic understanding of the impact of aquatic pollutants in organisms. These methods have included high throughput Omics technologies, including quantitative proteomics methods such as 2D differential in-gel electrophoresis (DIGE) and isobaric tagging for relative and absolute quantitation (iTRAQ). These methods are becoming more widely used in ecotoxicology studies to identify and characterize protein bioindicators of adverse effect. In teleost fish, iTRAQ has been used successfully in different fish species (e.g. fathead minnow, goldfish, largemouth bass) and tissues (e.g. hypothalamus and liver) to quantify relative protein abundance. Of interest for ecotoxicology is that many proteins commonly utilized as bioindicators of toxicity or stress are quantifiable using iTRAQ on a larger scale, providing a global baseline of biological effect from which to assess changes in the proteome. This review highlights the successes to date for high throughput quantitative proteomics using DIGE and iTRAQ in aquatic toxicology. Current challenges for the iTRAQ method for biomarker discovery in fish are the high cost and the lack of complete annotated genomes for teleosts. However, the use of protein homology from teleost fishes in protein databases and the introduction of hybrid LTQ-FT (Linear ion trap-Fourier transform) mass spectrometers with high resolution, increased sensitivity, and high mass accuracy are able to improve significantly the protein identification rates. Despite these challenges, initial studies utilizing iTRAQ for ecotoxicoproteomics have exceeded expectations and it is anticipated that the use of non-gel based quantitative proteomics will increase for protein biomarker discovery and for characterization of chemical mode of action.
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Affiliation(s)
- Christopher J Martyniuk
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5.
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Korte JJ, Sternberg RM, Serrano JA, Thoemke KR, Moen SM, Lillegard KE, Hornung MW, Tietge JE, Degitz SJ. Thyroid-stimulating hormone (TSH): measurement of intracellular, secreted, and circulating hormone in Xenopus laevis and Xenopus tropicalis. Gen Comp Endocrinol 2011; 171:319-25. [PMID: 21354158 DOI: 10.1016/j.ygcen.2011.02.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2010] [Revised: 02/03/2011] [Accepted: 02/20/2011] [Indexed: 11/29/2022]
Abstract
Thyroid-stimulating hormone (TSH) is an important regulator of the hypothalamic-pituitary-thyroid (HPT) axis in Xenopus laevis. To evaluate the role of this hormone on developing tadpoles, immunologically-based Western blots and sandwich ELISAs were developed for measuring intracellular (within pituitaries), secreted (ex vivo pituitary culture), and circulating (serum) amounts. Despite the small size of the tadpoles, these methods were able to easily measure intracellular and secreted TSH, and circulating TSH was measurable in situations where high levels were induced. The method was validated after obtaining a highly purified and enriched TSH sample using anti-TSH-β antibodies conjugated to magnetic beads. Subsequent mass-spectrometric analysis of the bands from SDS-PAGE and Western procedures identified the presence of amino acid sequences corresponding to TSH subunits. The purified sample was also used to prepare standard curves for quantitative analysis. The Western and ELISA methods had limits of detection in the low nanogram range. While the majority of the developmental work for these methods was done with X. laevis, the methods also detected TSH in Xenopus tropicalis. To our knowledge this is the first report of a specific detection method for TSH in these species, and the first to measure circulating TSH in amphibians. Examples of the utility of the methods include measuring a gradual increase in pituitary TSH at key stages of development, peaking at stages 58-62; the suppression of TSH secretion from cultured pituitaries in the presence of thyroid hormone (T4); and increases in serum TSH following thyroidectomy.
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Affiliation(s)
- Joseph J Korte
- Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, 6201 Congdon Blvd., Duluth, MN 55804, USA.
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Chen G, Zhang Y, Jin X, Zhang L, Zhou Y, Niu J, Chen J, Gu Y. Urinary proteomics analysis for renal injury in hypertensive disorders of pregnancy with iTRAQ labeling and LC-MS/MS. Proteomics Clin Appl 2011; 5:300-10. [PMID: 21538910 DOI: 10.1002/prca.201000100] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 01/15/2011] [Accepted: 01/18/2011] [Indexed: 12/18/2022]
Abstract
PURPOSE As a noninvasive examination, urinary proteomics is a very useful tool to identify renal disease. The purpose of the present study was to find differential proteins among women with preeclampsia, gestational hypertension and normal pregnancy, and to screen potential biomarkers for the early diagnosis of preeclampsia. EXPERIMENTAL DESIGN Urinary proteins were identified by iTRAQ labeling coupled with 2-D LC-MS/MS. The bioinformatics analysis was performed with the Metacore software and the International Protein Index (IPI) and the Gene Ontology (GO) Database. The differentially expressed proteins were verified by ELISA. RESULTS 362 nonredundant proteins were identified, 113 of which were expressed differentially between preeclampsia and normal pregnant group and 31 differential proteins among three groups. These differential proteins were associated with biological processes of blood coagulation, cell adhesion and differentiation, immune response and cytoskeleton development, etc. They interacted with each other in the network. The urinary angiotensinogen (AGT) was downregulated, which was consistent with the ELISA validation results. CONCLUSIONS AND CLINICAL RELEVANCE The present study found a multitude of differential proteins that might provide a clue for investigating the mechanism of proteinuria development in preeclampsia. Low urinary angiotensinogen levels were useful for identifying preeclampsia.
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Affiliation(s)
- Guixiang Chen
- Division of Nephrology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, P. R. China
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