Nitrotyrosine as a Biomarker of Diabetes pp. 177-203
Authors: (Magdalena Stobiecka and Maria Hepel, Department of Chemistry, State University of New York at Potsdam, Potsdam, NY, 13676, U.S.A)
Abstract: Recent advances in genetics, genomics, and proteomics offer a great opportunity for the identification of new biomarkers for diabetes.The newly discovered biomarkers have the potential to provide an increased accuracy in the diagnosisand classification of diabetes and, more importantly, to provide means for monitoring of the disease development and controlling the drug delivery in the applied therapeutic intervention. Accurate prediction and identification of diabetes using biomarkers is a key factor for disease prevention so that therapy can be provided to those individuals who are most likely to develop the disease or in early stages of the disease. There is now mounting evidence that oxidative and nitrosative stress resulting from hyperglycemia is involved in the development of diabetes and is implicated in the micro- and macrovascular complications of the disease.Different mechanisms involved in the pathogenesis of complications related to diabetes result from a single hyperglycemia-induced process of the overproduction of superoxide by the mitochondrial electron-transport chain. Such biomarkers of oxidative stress as nitrotyrosine and homocysteine show elevated levels and glutathione shows a decreased level in a progressing disease. In this study, the interactions of nitrotyrosine with gold nanoparticles and two fluorescent dyes with different spectral characteristics have been investigated. These interactions result in changes in the resonance elastic light scattering (RELS) and fluorescence quenching that can be utilized in designing assays for the biomarker. In contrast to homocysteine and glutathione that induce gold nanoparticle assembly in specific pH ranges, no aggregation of nanoparticles has been found in the presence of nitrotyrosine. The adsorptionmeasurements of nitrotyrosine and coumarin C120 on a QC/Au piezoelectrode corroboratethe observed RELS and static fluorescence quenching effects.