Oxygen: From Toxic Waste to Optimal (Toxic) Fuel of Life

Some 2.5 billion years ago, the great oxygenation event (GOE) led to a 105‐fold rise in atmospheric oxygen [O2], killing most species on Earth. In spite of the tendency to produce toxic reactive oxygen species (ROS), the highly exergonic reduction of O2 made it the ideal biological electron acceptor. During aerobic metabolism, O2 is reduced to water liberating energy, which is coupled to adenosine triphosphate (ATP) synthesis. Today, all organisms either aerobic or not need to deal with O2 toxicity. O2‐permeant organisms need to seek adequate [O2], for example, aquatic crustaceans bury themselves in the sea bottom where O2 is scarce. Also, the intestinal lumen and cytoplasm of eukaryotes is a microaerobic environment where many facultative bacteria or intracellular symbionts hide from oxygen. Organisms such as plants, fish, reptiles and mammals developed O2‐impermeable epithelia, plus specialized external respiratory systems in combination with O2‐binding proteins such as hemoglobin or leg‐hemoglobin control [O2] in tissues. Inside the cell, ROS production is prevented by rapid O2 consumption during the oxidative phosphorylation (OxPhos) of ATP. When ATP is in excess, OxPhos becomes uncoupled in an effort to continue eliminating O2. Branched respiratory chains, unspecific pores and uncoupling proteins (UCPs) uncouple OxPhos. One last line of resistance against ROS is deactivation by enzymes such as super oxide dismutase and catalase. Aerobic organisms profit from the high energy released by the reduction of O2, while at the same time they need to avoid the toxicity of ROS

Ácidos hidroxicinámicos en producción animal: farmacocinética, farmacodinamia y sus efectos como promotor de crecimiento. Revisión

Use of natural source additives in animal production is increasingly important because they potentially promote growth in ways similar to synthetic compounds, such as anabolic hormones and antibiotics, but without risks to animal or consumer health or degrading meat quality. Encompassing a wide variety of compounds extracted from different plant parts, natural origin additives can be administered as essential oils, mixtures of compounds or isolated compounds to function as medicinal remedies or dietary supplements. Phenolic compounds are widely used and include hydroxycinnamic acids, present in a variety of vegetables, fruits and grains. These acids exhibit interesting bioactivities such as antioxidant, antimicrobial, prevention of cardiovascular diseases and immunomodulation. Use of hydroxycinnamic acids in animal production is currently limited but may hold promise in promoting growth. Before this can occur further research is needed on their pharmacokinetics and pharmacodynamics, posology, exposition period and effects, as well as their possible metabolic routes and biotransformation in animal organisms. This review covers inclusion of hydroxycinnamic acids in livestock diets, their pharmacokinetic properties and pharmacodynamics, and findings on their effects in promoting growth and improving meat quality.El uso de aditivos de origen natural en producción animal ha tomado gran importancia en el sector pecuario, debido a su potencial de promover el crecimiento de una forma similar a los compuestos sintéticos como hormonas y antibióticos, pero sin causar posibles daños a la salud del animal, del consumidor o detrimento en la calidad de la carne. En los aditivos de origen natural existe una amplia variedad de compuestos, que son extraídos de distintas partes de las plantas, donde se toman ciertos aceites esenciales, mezclas de compuestos o compuestos aislados para utilizarse como remedios medicinales o suplementos alimenticios. Dentro de estos extractos, se encuentran los ácidos hidroxicinámicos, presentes en una gran variedad de vegetales, frutas y granos; los cuales presentan interesantes propiedades bioactivas como son, antioxidantes, antimicrobianos, preventivos de enfermedades cardiovasculares e inmunomoduladores. El uso de este tipo de aditivos en producción animal aún es limitado, pero se sugiere que su inclusión puede ser favorable como una estrategia para promover el crecimiento; sin embargo, dos aspectos importantes a estudiarse en los ácidos hidroxicinámicos es su farmacocinética y farmacodinamia, y a partir de allí establecer las condiciones de dosis, períodos de uso y efectos, además las posibles rutas y biotransformaciones que pueden ocurrir en el organismo animal. Esta revisión discute sobre la inclusión de ácidos hidroxicinámicos en dietas de animales de engorda, propiedades farmacocinéticas y farmacodinamias, y los hallazgos como promotores de crecimiento y sus efectos en la calidad de la carne

De novo assembly and transcriptome characterization of the freshwater prawn Palaemonetes argentinus: Implications for a detoxification response

Palaemonetes argentinus, an abundant freshwater prawn species in the northern and central region of Argentina, has been used as a bioindicator of environmental pollutants as it displays a very high sensitivity to pollutants exposure. Despite their extraordinary ecological relevance, a lack of genomic information has hindered a more thorough understanding of the molecular mechanisms potentially involved in detoxification processes of this species. Thus, transcriptomic profiling studies represent a promising approach to overcome the limitations imposed by the lack of extensive genomic resources for P. argentinus, and may improve the understanding of its physiological and molecular response triggered by pollutants. This work represents the first comprehensive transcriptome-based characterization of the non-model species P. argentinus to generate functional genomic annotations and provides valuable resources for future genetic studies. Trinity de novo assembly consisted of 24,738 transcripts with high representation of detoxification (phase I and II), anti-oxidation, osmoregulation pathways and DNA replication and bioenergetics. This crustacean transcriptome provides valuable molecular information about detoxification and biochemical processes that could be applied as biomarkers in further ecotoxicology studies.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Limnología "Dr. Raúl A. Ringuelet

Trypsin-Like Serine Proteases in Lutzomyia longipalpis – Expression, Activity and Possible Modulation by Leishmania infantum chagasi

Background: Midgut enzymatic activity is one of the obstacles that Leishmania must surpass to succeed in establishing infection. Trypsins are abundant digestive enzymes in most insects. We have previously described two trypsin cDNAs of L. longipalpis: one (Lltryp1) with a bloodmeal induced transcription pattern, the other (Lltryp2) with a constitutive transcription pattern. We have now characterized the expression and activity of trypsin-like proteases of Lutzomyia longipalpis, the main vector of visceral leishmaniasis in Brazil. Methodology and Principal Findings: In order to study trypsin expression profiles we produced antibodies against peptides specific for Lltryp1 and Lltryp2. The anti-Lltryp1-peptide antibody revealed a band of 28 kDa between 6 and 48 hours. The anti-Lltryp2 peptide antibody did not evidence any band. When proteinaceous substrates (gelatin, hemoglobin, casein or albumin) were co-polymerized in polyacrylamide gels, insect midguts obtained at 12 hours after feeding showed a unique proteolytic pattern for each substrate. All activity bands were strongly inhibited by TLCK, benzamidine and 4-amino-benzamidine, indicating that they are trypsin-like proteases. The trypsin-like activity was also measured in vitro at different time points after ingestion of blood or blood containing Leishmania infantum chagasi, using the chromogenic substrate BArNA. L. longipalpis females fed on blood infected with L. i. chagasi had lower levels of trypsin activity after 12 and 48 hours than non-infected insects, suggesting that the parasite may have a role in this modulation. Conclusions and Significance: Trypsins are important and abundant digestive enzymes in L. longipalpis. Protein production and enzymatic activity followed previously identified gene expression of a blood modulated trypsin gene. A decrease of enzymatic activity upon the parasite infection, previously detected mostly in Old World vectors, was detected for the first time in the natural vector-parasite pair L. longipalpis-L. i. chagasi

Understanding the Digestive Peptidases from Crustaceans: from Their Biochemical Basis and Classical Perspective to the Biotechnological Approach

Scientific studies about decapod crustaceans’ digestive physiology have increased, being an important topic with novel results in the last years. This revision aims to show how the study of crustacean peptidases has evolved, from the classical biochemical characterization studies to the assessment of their usefulness in biotechnological and industrial processes, with emphasis on commercial species of interest to world aquaculture and fisheries. First studies determined the proteolytic activity of the midgut gland crude extracts and evaluated the optimum biochemical properties of specific enzymes. Peptidase’s identity was determined using inhibitors and specific protein substrates on tube tests and electrophoresis gels. Later, various studies focused on the characterization of purified peptidases and their gene expression. Recently, the integrated mechanisms of enzyme participation during the digestive process of food protein have been established using novel techniques. Scientific research has revealed some of the potential biotechnological applications of crustacean peptidases in the food industry and other processes. However, the knowledge field is enormous, and there is much to explore and study in the coming years.Fil: Muhlia Almazán, Adriana Teresita. Centro de Investigación E/alimentos y Desarrollo A.c; MéxicoFil: Fernandez Gimenez, Analia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin