Sphingolipid Effects on the Plasma Membrane Produced by Addition of Fumonisin B1 to Maize Embryos.

Fumonisin B1 is a mycotoxin produced by Fusarium verticillioides that modifies the membrane properties from animal cells and inhibits complex sphingolipids synthesis through the inhibition of ceramide synthase. The aim of this work was to determine the effect of Fumonisin B1 on the plant plasma membrane when the mycotoxin was added to germinating maize embryos. Fumonisin B1 addition to the embryos diminished plasma membrane fluidity, increased electrolyte leakage, caused a 7-fold increase of sphinganine and a small decrease in glucosylceramide in the plasma membrane, without affecting phytosphingosine levels or fatty acid composition. A 20%-30% inhibition of the plasma membrane H+-ATPase activity was observed when embryos were germinated in the presence of the mycotoxin. Such inhibition was only associated to the decrease in glucosylceramide and the addition of exogenous ceramide to the embryos relieved the inhibition of Fumonisin B1. These results indicate that exposure of the maize embryos for 24 h to Fumonisin B1 allowed the mycotoxin to target ceramide synthase at the endoplasmic reticulum, eliciting an imbalance of endogenous sphingolipids. The latter disrupted membrane properties and inhibited the plasma membrane H+-ATPase activity. Altogether, these results illustrate the mode of action of the pathogen and a plant defense strategy.

FOXP2 and language alterations in psychiatric pathology / FOXP2 and language alterations in psychiatric pathology

Abstract Background From the first reports of the linguist Noam Chomsky it has become clear that the development of language has an important genetic component. Several reports in families have shown the relationship between language disorders and genetic polymorphisms. The FOXP2 gene has been a fundamental piece for the understanding of language development. This gene codes for a transcription factor containing a forkhead domain of DNA binding and participates in the regulation of the expression of a large number of genes involved in the embryonic development of fundamental neuronal structures needed for the development of speech and language. Objective To present an updated view of the relationship between FOXP2 and language alterations in psychiatric pathology. Method Narrative review of information reported in databases on the recent advances supporting genetic participation in language disorders of psychiatric illness. Results Update of content related to FOXP2 and its participation in language alterations in psychiatric diseases. Discussion and conclusion Advances in the genetic study of language disorders in psychiatric pathology open up new avenues of investigation that allow us to explore how language emerged and how it evolved, as well as to carry out comparative studies on the structure and functioning of genes to approach the understanding of this complex characteristic that makes us human.

Resumen Antecedentes Desde los primeros reportes del lingüista Noam Chomsky ha quedado claro que el desarrollo del lenguaje tiene un importante componente genético. Diversos reportes en familias han mostrado la relación entre los trastornos del lenguaje y ciertos marcadores genéticos. El gen FOXP2 ha sido una pieza fundamental para entender el desarrollo del lenguaje. Se trata de un gen que codifica para un factor de transcripción con un dominio forkhead de unión al DNA y que participa en la regulación de la expresión de un gran número de genes durante el desarrollo embrionario de estructuras neuronales fundamentales para el desarrollo del habla y el lenguaje. Objetivo Presentar un panorama actualizado de la relación del gen FOXP2 en las alteraciones del lenguaje en la patología psiquiátrica. Método Revisión narrativa de la información reportada en diversas bases de datos sobre los recientes avances que soportan la participación genética en las alteraciones del lenguaje presentes en enfermedades psiquiátricas. Resultados Actualización del contenido relacionado con el gen FOXP2 y su participación en las alteraciones del lenguaje en las enfermedades psiquiátricas. Discusión y conclusión Los avances en el estudio genético de las alteraciones del lenguaje en la patología psiquiátrica abren nuevos caminos de investigación que permiten explorar cómo surgió y cómo ha evolucionado el lenguaje, así como para llevar a cabo estudios comparativos sobre la estructura y el funcionamiento de genes para aproximarse al entendimiento de esta compleja característica que nos hace humanos.

"Gestaltomics": Systems Biology Schemes for the Study of Neuropsychiatric Diseases.

The integration of different sources of biological information about what defines a behavioral phenotype is difficult to unify in an entity that reflects the arithmetic sum of its individual parts. In this sense, the challenge of Systems Biology for understanding the "psychiatric phenotype" is to provide an improved vision of the shape of the phenotype as it is visualized by "Gestalt" psychology, whose fundamental axiom is that the observed phenotype (behavior or mental disorder) will be the result of the integrative composition of every part. Therefore, we propose the term "Gestaltomics" as a term from Systems Biology to integrate data coming from different sources of information (such as the genome, transcriptome, proteome, epigenome, metabolome, phenome, and microbiome). In addition to this biological complexity, the mind is integrated through multiple brain functions that receive and process complex information through channels and perception networks (i.e., sight, ear, smell, memory, and attention) that in turn are programmed by genes and influenced by environmental processes (epigenetic). Today, the approach of medical research in human diseases is to isolate one disease for study; however, the presence of an additional disease (co-morbidity) or more than one disease (multimorbidity) adds complexity to the study of these conditions. This review will present the challenge of integrating psychiatric disorders at different levels of information (Gestaltomics). The implications of increasing the level of complexity, for example, studying the co-morbidity with another disease such as cancer, will also be discussed.

Proteomic Profiling Reveals the Induction of UPR in Addition to DNA Damage Response in HeLa Cells Treated With the Thiazolo[5,4-b]Quinoline Derivative D3ClP.

9-[(3-chloro)phenylamine]-2-[3-(diethylamine)propylamine]thiazolo[5,4-b]quinolone (D3ClP) is a bioisostere of N-(4-(acridin-9-ylamino)-3-methoxyphenyl)methanesulfonamide (m-AMSA) a DNA topoisomerase II inhibitor with proven cytotoxic activity and known to induce DNA damage and apoptotic cell death in K562 cells. However, recent evidence is not consistent with DNA topoisomerase II (DNA TOP2) as the primary target of D3ClP, in contrast to m-AMSA. We provide evidence of histone γH2AX phosphorylation at Ser135 in HeLa cells treated with D3ClP, a marker of DNA double strand repair through Mre11-Rad50-Nbs1 (MRN) pathway. Using two-dimensional gel electrophoresis and mass spectrometry, the upregulation of the protein GRP78, the cleavage of Cytokeratin 18, and the downregulation of prothymosine, calumenin, and the α chain of the nascent polypeptide associated complex were observed in HeLa cells treated with D3ClP. An increase in GRP78 has been related with the onset and progression of the unfolded protein response (UPR), a process aimed to reduce endoplasmic reticulum (ER) stress and protein misfolding. The IRE1-α dependent splicing of mRNA encoding X-box binding protein 1 was detected. Microtubule-associated Proteins 1A/1B, Light Chain 3-II (LC3b-II) accumulation was observed, and suggest some involvement of autophagy. The production of the pro-apoptotic protein DNA-damage-inducible protein 153 (GADD-153) was also detected. These results, are consistent with the induction of the UPR and the DNA-Damage Response in D3ClP-treated HeLa cells, and are also consistent with a concurrent apoptotic cell death. J. Cell. Biochem. 118: 1164-1173, 2017. © 2016 Wiley Periodicals, Inc.

Fatty acid profiles from the plasma membrane and detergent resistant membranes of two plant species.

It is essential to establish the composition of the plant plasma membrane in order to understand its organization and behavior under continually changing environments. Knowledge of the lipid phase, in particular the fatty acid (FA) complex repertoire, is important since FAs determine many of the physical-chemical membrane properties. FAs are constituents of the membrane glycerolipid and sphingolipid backbones and can also be linked to some sterols. In addition, FAs are components of complex lipids that can constitute membrane micro-domains, and the use of detergent-resistant membranes is a common approach to study their composition. The diversity and cellular allocation of the membrane lipids containing FAs are very diverse and the approaches to analyze them provide only general information. In this work, a detailed FA analysis was performed using highly purified plasma membranes from bean leaves and germinating maize embryos and their respective detergent-resistant membrane preparations. The analyses showed the presence of a significant amount of very long chain FAs (containing 28C, 30C and 32C), in both plasma membrane preparations from bean and maize, that have not been previously reported. Herein is demonstrated that a significant enrichment of very long chain saturated FAs and saturated FAs can occur in detergent-resistant membrane preparations, as compared to the plasma membranes from both plant species. Considering that a thorough analysis of FAs is rarely performed in purified plasma membranes and detergent-resistant membranes, this work provides qualitative and quantitative evidence on the contributions of the length and saturation of FAs to the organization of the plant plasma membrane and detergent-resistant membranes.

Comparative proteomic analysis of thiol proteins in the liver after oxidative stress induced by diethylnitrosamine.

Conversion of protein -SH groups to disulfides is an early event during protein oxidation, which has prompted great interest in the study of thiol proteins. Chemical carcinogenesis is strongly associated with the formation of reactive oxygen species (ROS). The goal of this study was to detect thiol proteins that are sensitive to ROS generated during diethylnitrosamine (DEN) metabolism in the rat liver. DEN has been widely used to induce experimental hepatocellular carcinoma. We used modified redox-differential gel electrophoresis (redox-DIGE method) and mass spectrometry MALDI-TOF/TOF to identify differential oxidation protein profiles associated with carcinogen exposure. Our analysis revealed a time-dependent increase in the number of oxidized thiol proteins after carcinogen treatment; some of these proteins have antioxidant activity, including thioredoxin, peroxirredoxin 2, peroxiredoxin 6 and glutathione S-transferase alpha-3. According to functional classifications, the identified proteins in our study included chaperones, oxidoreductases, activity isomerases, hydrolases and other protein-binding partners. This study demonstrates that oxidative stress generated by DEN tends to increase gradually through DEN metabolism, causes time-dependent necrosis in the liver and has an oxidative effect on thiol proteins, thereby increasing the number of oxidized thiol proteins. Furthermore, these events occurred during the hepatocarcinogenesis initiation period.

The role of master regulators in the metabolic/transcriptional coupling in breast carcinomas.

Metabolic transformations have been reported as involved in neoplasms survival. This suggests a role of metabolic pathways as potential cancer pharmacological targets. Modulating tumor's energy production pathways may become a substantial research area for cancer treatment. The significant role of metabolic deregulation as inducing transcriptional instabilities and consequently whole-system failure, is thus of foremost importance. By using a data integration approach that combines experimental evidence for high-throughput genome wide gene expression, a non-equilibrium thermodynamics analysis, nonlinear correlation networks as well as database mining, we were able to outline the role that transcription factors MEF2C and MNDA may have as main master regulators in primary breast cancer phenomenology, as well as the possible interrelationship between malignancy and metabolic dysfunction. The present findings are supported by the analysis of 1191 whole genome gene expression experiments, as well as probabilistic inference of gene regulatory networks, and non-equilibrium thermodynamics of such data. Other evidence sources include pathway enrichment and gene set enrichment analyses, as well as motif comparison with a comprehensive gene regulatory network (of homologue genes) in Arabidopsis thaliana. Our key finding is that the non-equilibrium free energies provide a realistic description of transcription factor activation that when supplemented with gene regulatory networks made us able to find deregulated pathways. These analyses also suggest a novel potential role of transcription factor energetics at the onset of primary tumor development. Results are important in the molecular systems biology of cancer field, since deregulation and coupling mechanisms between metabolic activity and transcriptional regulation can be better understood by taking into account the way that master regulators respond to physicochemical constraints imposed by different phenotypic conditions.

Fumonisin B1, a sphingoid toxin, is a potent inhibitor of the plasma membrane H+-ATPase.

Fumonisin B(1) (FB(1)) is an amphipathic toxin produced by the pathogenic fungus Fusarium verticillioides which causes stem, root and ear rot in maize (Zea mays L.). In this work, we studied the action of FB(1) on the plasma membrane H(+)-ATPase (EC 3.6.1.34) from germinating maize embryos, and on the fluidity and lipid peroxidation of these membranes. In maize embryos the toxin at 40 microM inhibited root elongation by 50% and at 30 microM decreased medium acidification by about 80%. Irrespective of the presence and absence of FB(1), the H(+)-ATPase in plasma membrane vesicles exhibited non-hyperbolic saturation kinetics by ATPH-Mg, with Hill number of 0.67. Initial velocity studies revealed that FB(1) is a total uncompetitive inhibitor of this enzyme with an inhibition constant value of 17.5+/-1 microM. Thus FB(1) decreased V(max) and increased the apparent affinity of the enzyme for ATP-Mg to the same extent. Although FB(1) increased the fluidity at the hydrophobic region of the membrane, no correlation was found with its effect on enzyme activity, since both effects showed different FB(1)-concentration dependence. Peroxidation of membrane lipids was not affected by the toxin. Our results suggest that, under in vivo conditions, the plasma membrane H(+)-ATPase is a potentially important target of the toxin, as it is inhibited not only by FB(1) but also by its structural analogs, the sphingoid intermediates, which accumulate upon the inhibition of sphinganine N-acyltransferase by this toxin.