Metabolomics: A Powerful Tool to Understand the Schizophrenia Biology.

ABSVTRACT: Schizophrenia, as any other psychiatric disorder, is a multifactorial and complex illness whose etiology is not completely established. Therefore, studies involving strategies that are able to describe the molecular alterations caused by the disease and, consequently, indicate the altered metabolic pathways are of increasing interest. Metabolomics is a very suitable approach that can be applied for this task, since it consists of the evaluation of the set of metabolites contained in a biological system undergoing a biological process, such as a disease or treatment. In metabolomics, state-of-the-art analytical techniques (mass spectrometry and nuclear magnetic resonance) are employed to identify and quantify the metabolites present in the studied biological samples, and chemometric and bioinformatic tools are applied to determine the specific metabolites and metabolic pathways that are relevant to the biological process under investigation. The aim of this chapter is to describe the basic principles of metabolomics, how this strategy can improve the understanding of the schizophrenia biology, and the findings obtained so far.

The New Omics Era into Systems Approaches: What Is the Importance of Separation Techniques?

Omics sciences have been facing challenges in different fields, especially in life sciences. One of these challenges involves assessing biology into systems interpretation. With the advance of genomics, molecular biology has been projected into the realm of systems biology. In a different direction, systems approaches are making definitive strides toward scientific understanding and biotechnological applications. Separation techniques provided meaningful progress in the omics era, conducting the classical molecular biology to contemporary systems biology. In this introductory chapter, the relevance of these techniques to the development of different omics sciences, within the systems biology context, will be discussed.

Comparative proteomic analysis of Xanthomonas citri ssp. citri periplasmic proteins reveals changes in cellular envelope metabolism during in vitro pathogenicity induction.

Citrus canker is a plant disease caused by Gram-negative bacteria from the genus Xanthomonas. The most virulent species is Xanthomonas citri ssp. citri (XAC), which attacks a wide range of citrus hosts. Differential proteomic analysis of the periplasm-enriched fraction was performed for XAC cells grown in pathogenicity-inducing (XAM-M) and pathogenicity-non-inducing (nutrient broth) media using two-dimensional electrophoresis combined with liquid chromatography-tandem mass spectrometry. Amongst the 40 proteins identified, transglycosylase was detected in a highly abundant spot in XAC cells grown under inducing condition. Additional up-regulated proteins related to cellular envelope metabolism included glucose-1-phosphate thymidylyltransferase, dTDP-4-dehydrorhamnose-3,5-epimerase and peptidyl-prolyl cis-trans-isomerase. Phosphoglucomutase and superoxide dismutase proteins, known to be involved in pathogenicity in other Xanthomonas species or organisms, were also detected. Western blot and quantitative real-time polymerase chain reaction analyses for transglycosylase and superoxide dismutase confirmed that these proteins were up-regulated under inducing condition, consistent with the proteomic results. Multiple spots for the 60-kDa chaperonin and glyceraldehyde-3-phosphate dehydrogenase were identified, suggesting the presence of post-translational modifications. We propose that substantial alterations in cellular envelope metabolism occur during the XAC infectious process, which are related to several aspects, from defence against reactive oxygen species to exopolysaccharide synthesis. Our results provide new candidates for virulence-related proteins, whose abundance correlates with the induction of pathogenicity and virulence genes, such as hrpD6, hrpG, hrpB7, hpa1 and hrpX. The results present new potential targets against XAC to be investigated in further functional studies.