Immunoproteomics of Helicobacter pylori infection in patients with atrophic body gastritis, a predisposing condition for gastric cancer.

Atrophic body gastritis is considered an outcome of H. pylori infection at high risk for gastric cancer. Immunoproteomics has been used to detect H. pylori antigens, which may act as potential markers for neoplastic disease and may be used in specific serological tests. We used immunoproteome technology to identify H. pylori antigens, recognized by sera from patients with atrophic body gastritis. Here, we performed 2DE protein maps of H. pylori strain 10K, probed against single sera from 3 groups of H. pylori-positive patients (atrophic body gastritis; intestinal-type gastric cancer; peptic ulcer) and negative controls. Immunoreactive spots were identified by MALDI-TOF-MS. A total of 155 immunoreactive spots were detected corresponding to 14.1% of total spots detected in our reference map of H. pylori strain 10K. Sera from atrophic body gastritis (40.5±2%) and gastric cancer patients (25.9±1.8%) showed a significantly higher and stronger mean immunoreactivity versus H. pylori antigens compared to peptic ulcer patients (11.2±1.3%). The average intensity of immunoreactivity of sera from atrophic body gastritis and gastric cancer patients was significantly stronger compared to peptic ulcer patients. Sera from atrophic body gastritis and gastric cancer patients differentially recognized 17 H. pylori spots. Immunoproteome technology may discriminate between different H. pylori-related disease phenotypes showing a serological immunorecognition pattern common to patients with gastric cancer and atrophic body gastritis, its precursor condition. This tool may be promising for developing specific serological tests to identify patients with gastritis at high risk for gastric cancer, to be evaluated in prospective investigations.

Oxidative damage mediated by herbicides on yeast cells.

Agricultural herbicides are among the most commonly used pesticides worldwide, posing serious concerns for both humans, exposed to these chemicals through many routes, and the environment. To clarify the effects of three herbicides as commercial formulations (namely, Pointer, Silglif, and Proper Energy), parameters related to oxidative issues were investigated on an autochthonous wine yeast strain. It was demonstrated that herbicides were able to affect the enzymatic activities of catalase and superoxide dismutase, as well as to induce carbonylation and thiol oxidation as post-translational modifications of proteins. Saccharomyces cerevisiae is an optimal model system to study responses to xenobiotics and oxidative stress. Thus, the results obtained could further the understanding of mechanisms underlying the toxicity of herbicides.

Proteomics and redox-proteomics of the effects of herbicides on a wild-type wine Saccharomyces cerevisiae strain.

Several toxicological and environmental problems are associated with the extensive use of agricultural pesticides, such as herbicides. Nevertheless, little is known about the toxic effects of formulated herbicides, since many studies have been carried out using pure active molecules alone. In this work, we used as an eukaryotic model system an autochthonous wine yeast strain to investigate the effects of three commercial herbicides, currently used in the same geographical area from where this strain had been isolated. We carried out a comparative proteomic analysis to study the effects at the protein level of the herbicide-related stress, and found that the herbicides tested can alter the yeast proteome producing responses that share homologies with those observed treating yeast cells with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) or with well-known oxidizing agents. We evaluated, through redox-proteomic techniques, protein carbonylation as a biomarker of oxidative stress. This analysis showed that herbicide-induced carbonylation is a dynamic phenomenon with degrees of selectivity.