Evolutionary view of acyl-CoA diacylglycerol acyltransferase (DGAT), a key enzyme in neutral lipid biosynthesis

<p>Abstract</p> <p>Background</p> <p>Triacylglycerides (TAGs) are a class of neutral lipids that represent the most important storage form of energy for eukaryotic cells. DGAT (acyl-CoA: diacylglycerol acyltransferase; EC 2.3.1.20) is a transmembrane enzyme that acts in the final and committed step of TAG synthesis, and it has been proposed to be the rate-limiting enzyme in plant storage lipid accumulation. In fact, two different enzymes identified in several eukaryotic species, DGAT1 and DGAT2, are the main enzymes responsible for TAG synthesis. These enzymes do not share high DNA or protein sequence similarities, and it has been suggested that they play non-redundant roles in different tissues and in some species in TAG synthesis. Despite a number of previous studies on the DGAT1 and DGAT2 genes, which have emphasized their importance as potential obesity treatment targets to increase triacylglycerol accumulation, little is known about their evolutionary timeline in eukaryotes. The goal of this study was to examine the evolutionary relationship of the DGAT1 and DGAT2 genes across eukaryotic organisms in order to infer their origin.</p> <p>Results</p> <p>We have conducted a broad survey of fully sequenced genomes, including representatives of Amoebozoa, yeasts, fungi, algae, musses, plants, vertebrate and invertebrate species, for the presence of DGAT1 and DGAT2 gene homologs. We found that the DGAT1 and DGAT2 genes are nearly ubiquitous in eukaryotes and are readily identifiable in all the major eukaryotic groups and genomes examined. Phylogenetic analyses of the DGAT1 and DGAT2 amino acid sequences revealed evolutionary partitioning of the DGAT protein family into two major DGAT1 and DGAT2 clades. Protein secondary structure and hydrophobic-transmembrane analysis also showed differences between these enzymes. The analysis also revealed that the MGAT2 and AWAT genes may have arisen from DGAT2 duplication events.</p> <p>Conclusions</p> <p>In this study, we identified several DGAT1 and DGAT2 homologs in eukaryote taxa. Overall, the data show that DGAT1 and DGAT2 are present in most eukaryotic organisms and belong to two different gene families. The phylogenetic and evolutionary analyses revealed that DGAT1 and DGAT2 evolved separately, with functional convergence, despite their wide molecular and structural divergence.</p

Carotenoid extraction from the gonad of the scallop Nodipecten nodosus (Linnaeus, 1758) (Bivalvia: Pectinidae)

In marine bivalve mollusks, unsaturated molecules called carotenoids are present in the natural diet and play an important role in different biological process, especially in reproduction. In order to gain more insights into these compounds in Nodipecten nodosus it was necessary to develop a suitable protocol for extraction of carotenoids from the gonads. Female gonads of cultured scallops (75 mm length) were lyophilized and macerated in liquid N2. To verify the effect of composition in organosolvents on the extracting solutions, two organic solvents were tested: acetone and hexane (Ac = O:Hex) at four ratios, 1:1, 1:3, 1:5, and 2:3, in four static extraction times: 0, 5, 10, and 15 minutes. Total carotenoids and astaxanthin contents were determined in the crude extracts by UV-visible spectrophotometry and high performance liquid chromatography (HPLC), respectively. Triplicate aliquots of 50 mg were used for each treatment. The results indicated that the best single extraction (0.312 ± 0.016 µg carotenoids/mg) was attained with Ac = O: Hex 1:3, for 15 minutes. Through exhaustive extraction methodology (10x), a superior yield (0.41 ± 0.001 µg carotenoids/mg) was obtained from a gonad sample in comparison to the highest value found for a single extraction. Astaxanthin content was reduced by 8.6% in carotenoid extract preservation assay, i.e., -18 °C, 26 days incubation, under N2 atmosphere

Sexual stages of the female portion in the scallop Nodipecten nodosus (Linn\ue9, 1758) and astaxanthin quantity in each stage

This work describes the gametogenic cycle of the scallop Nodipecten nodosus kept in a culture system. To this end, during one year, samples were taken from the broodstocks every 30 days to be submitted to macroscopic and microscopic analyses and to measure the amount of astaxanthin. To perform the microscopic evaluation, 5 &#956; slices from the median portion of the female part of the gonad were submitted to the pattern methodology for histological analyses with paraffin and HE coloration. The remaining portion of the female gonad was lyophilised to extract and quantify the levels of astaxanthin using HPLC. The microscopic analyses revealed four well defined stages for the reproductive cycle. Analyses of data taken throughout the year indicated preferential spawning periods from December to January and from July to September. The astaxanthin analyses showed higher amounts of this carotenoid during the advanced pre-spawning and the initial spawning periods than during gametogenesis, initial pre-spawning, advanced spawning, and the spent stages. According to these results, it was possible to establish a descriptive table of the sexual stages of the female portion of the gonad and the amount of astaxanthin in the sexual stage of the scallop Nodipecten nodosus

Monitoramento e avaliação dos efeitos colaterais da quimioterapia em pacientes com câncer de cólon Monitoreo y evaluación de los efectos colaterales de la quimioterapia en pacientes con neoplasia de colon Monitoring and evaluation of side effects of chemotherapy in patients with colon cancer

Este estudo objetivou monitorar e avaliar a ocorrência e grau de intensidade da náusea, vômito e diarréia em pacientes com neoplasia de cólon, submetidos à quimioterapia ambulatorial, que receberam informações de enfermagem para o manejo desses sintomas. Fizeram parte do estudo 17 pacientes tratados com 5-Fluorouracil e baixas doses de ácido folínico, no Ambulatório de Quimioterapia de Adultos do Hospital São Paulo/Universidade Federal de São Paulo. Foram elaborados instrumentos para o registro da ocorrência e grau de intensidade desses sintomas e folhetos com informações sobre o seu manejo. As informações e o seguimento foram realizados pela enfermeira do setor, durante as consultas de enfermagem. Os resultados evidenciaram que a maioria dos pacientes (82,4%) apresentou pelo menos um dos sinais e sintomas estudados, entre o primeiro e o 21º dias do ciclo de tratamento. A náusea foi o sintoma mais freqüente (76,5%), com pico no 4º e 5º dias do ciclo, seguida da diarréia (70,5%), com pico no 7º dia e, por último o vômito (53,0%), com pico no 5º dia. Quanto ao grau de intensidade desses sintomas, a maioria dos pacientes situou-se no grau 1, estabelecido como aceitável para o estudo, indicando que as orientações de enfermagem e o acompanhamento contínuo contribuíram para a maior efetividade do manejo desses sintomas por parte dos pacientes.<br>Este estudio tuvo como objetivo monitorear y evaluar la frecuencia y el grado de intensidad de la náusea, vómito y diarrea en pacientes con neoplasia de colon sometidos a quimioterapia ambulatoria que recibieron información de enfermería para el manejo de esos síntomas. Participaron del estudio 17 pacientes tratados con 5-Fluorouracil y bajas dosis de ácido folínico, en el Ambulatorio de Quimioterapia de Adultos del Hospital São Paulo / Universidad Federal de São Paulo, Brasil. Para el registro de la frecuencia e intensidad de esos síntomas fueron elaborados instrumentos y guías con informaciones de cómo manejarlos. Las informaciones y seguimiento de los pacientes fueron realizados por la enfermera del sector durante la consulta de enfermería. Los resultados evidenciaron que la mayoría de los pacientes (82,4%) presentó por lo menos uno de los síntomas estudiados, entre el primero y 21º día del ciclo de tratamiento. La náusea fue el síntoma más frecuente (76,5%), presentando pico en el 4º y 5º días del ciclo. Enseguida la diarrea (70,5%) con pico en el 7º día y, por ultimo, el vómito (53,0%) con pico en el 5º día. Cuanto al grado de intensidad de los síntomas, la mayoría de los pacientes se situó en el grado 1, establecido como aceptable para este estudio, indicando que las orientaciones de enfermería y el seguimiento continuo contribuyeron para la mayor efectividad del manejo de esos síntomas por parte de los pacientes.<br>This study aimed to monitor and evaluate the occurrence and intensity level of nausea, vomiting and diarrhea in patients with colon cancer, submitted to outpatient chemotherapy, who received nursing information for handling these symptoms. Study participants were 17 patients, who were treated with 5-Fluorouracil and low doses of folinic acid, at the Adult Outpatient Chemotherapy Clinic of the Hospital São Paulo/Federal University of São Paulo, Brazil. Instruments were elaborated for registering these symptoms' occurrence and intensity level and a patient guide for handling them. The information and patient monitoring were carried out by the nurse during the consultations. The results showed that most of the patients (82.4%) displayed at least one of the signs and symptoms under study between the first and the 21st day of the treatment cycle. Nausea was the most frequent symptom (76.5%), with a peak on the 4th and 5th day of the cycle, followed by diarrhea (70.5%), with a peak on the 7th day, and vomiting (53.0%), with a peak on the 5th day. Regarding the intensity of these symptoms, most patients were classified as level 1, which was established as acceptable for this study. These results indicate that the nursing instructions and the continuous monitoring contributed to the effectiveness of the patient's symptom management