Tissue composition and haemolymphatic metabolites during gonadal development in Aegla platensis (Crustacea, Decapoda) maintained in experimental culture

This study describes the variation of tissue composition and haemolymphatic metabolites in the anomuran crab A. platensis, which was maintained for 90, 120, 150, and 180 days under laboratory conditions, and relates the data collected to reproductive aspects of this species. Individuals were collected during the winter from Mineiro Creek, in Rio Grande do Sul, Brazil. Some of the individuals were killed when collected and the remaining animals were maintained in a laboratory for different time periods using a commercial diet. Haemolymph, hepatopancreas and gonads were removed at different times of cultivation to determine their biochemical composition using spectrophotometric methods. Hepatosomatic and gonadosomatic indexes were determined. Statistical analysis revealed significant differences between the sexes in all metabolites except in the proteins levels in the haemolymph. We observed an increase of ovigerous females kept under the same culture conditions between 120 and 150 days and we found an increase in the gonadosomatic index and a decrease in the hepatosomatic index in both sexes for the same times. Results showed that the regular food supply caused an increase in the gonadosomatic index in both sexes during all the time periods when compared to the results of animals from the natural environment. We also observed that the females used part of their hepatopancreatic reserves for vitellogenesis and gametogenesis, but the nutrients obtained from the other tissues and the diet were very important for supporting reproduction. Males used the metabolic reserves for growth, gametogenesis, and reproductive behaviors. This study indicates that reproductive events depend on a regular food supply.(Composição tecidual e metabolitos hemolinfaticos durante o desenvolvimento gonadal de Aegla platensis (Crustacea, Decapoda) mantidas em cultura experimental). Este estudo descreve a variação da composição tecidual e metabólitos hemolinfáticos nos caranguejos anomuros A. platensis mantidos por 90, 120, 150 e 180 dias no laboratório, e relaciona esses dados com os aspectos reprodutivos. Os animais foram coletados no arroio do Mineiro, Rio Grande do Sul, Brasil durante o inverno. Parte dos animais foi sacrificado em campo, e os restantes animais foram mantidos em laboratório por diferentes períodos com uma dieta comercial. A hemolinfa, o hepatopâncreas e as gônadas foram retiradas em diferentes épocas de cultivo para determinar a sua composição bioquímica por métodos espectrofotométricos. Os índices hepatossomático e gonadossomático foram determinados. A análise estatística revelou diferenças significativas entre os sexos em todos os seus metabolitos, exceto nos níveis de proteínas na hemolinfa. Observamos um aumento de fêmeas ovígeras mantidas sob as condições de cultivo entre 120 e 150 dias e encontramos um aumento do índice gonadossomático e uma diminuição do índice hepatossomático em ambos os sexos no mesmo periodo. Os resultados mostraram que o fornecimento regular de alimentos provocou um aumento no índice gonadossomático em ambos os sexos durante todo o período, quando comparado com os resultados dos animais do ambiente natural. Também foi observado que as fêmeas utilizadas parte das suas reservas do hepatopâncreas para a vitelogênese e a gametogênese, mas os nutrientes obtidos a partir de outros tecidos e da dieta foram muito importantes para apoiar a reprodução. Os machos utilizaram a reserva metabólica para o crescimento, gametogênese e comportamentos reprodutivos. Este estudo indica que os eventos reprodutivos dependem de um fornecimento regular de alimentos

New records and extension of the known distribution of some freshwater shrimps in Brazil

Freshwater prawns are distributed in rivers and streams of inland and brackish waters throughout America. In Brazilian waters are registered 35 species into 4 families (Atyidae, Euryrhynchidae, Palaemonidae, and Sergestidae). Information about the geographic distribution of this fauna is scattered in the literature and frequently not founded on documented data in scientific collections. Here we examined a series of specimens and detected several new records and extension of the known distribution of some freshwater shrimps in Brazil

External Morphology and Ultrastructure of Tegumental Glands of Aegla platensis (Crustacea, Anomura, Aeglidae) Pleopods: Might They Play A Role in Egg Attachment?

Egg incubation on the female abdomen is the parental care behavior observed in aeglids, in which eggs are kept adhered to maternal pleopods and maintained, cleaned and aerated. In A. platensis, egg attachment occurs with the aid of pleopodal setae, which are twisted around their axis in the distal region, forming the funiculus, and pleopodal glands, which are responsible for the production of the adhesive substance that seems to be involved in egg fixation to pleopodal setae. Those glands are acini formed by secretory cells arranged concentrically around a central duct, giving them a rosette appearance. Two types of secretory cells were observed, those that produce electron-lucid vesicles and those having electron-dense ones. Both kinds of vesicles are released in a duct whose opening pore is located on the pleopodal surface and constitute the adhesive substance that coats eggs and pleopodal setae, ensuring egg fixation to the female body and maternal care maintenance. This study investigates the internal and external morphology of Aegla platensis pleopods, to understand the egg attachment process and identify the structures involved in this phenomenon. Three microscopy techniques are used: scanning electron microscopy (SEM), transmission electron microscopy (TEM), and optical microscopy (OM)

Metabolismo intermediário do tecido branquial do lagostim Parastacus varicosus (Decapoda: Parastacidae) na Bacia do Rio Gravataí, Rio Grande do Sul, Brasil

 Specialized literature has demonstrated, in Decapods, that anterior gills are morphologically and physiologically adapted for gas exchange and breathing, while the posterior gills are specialized for osmorregulation. The goal of this work was to analyze the seasonal variations of the intermediate metabolism of the gills of Parastacus varicosus, relating variation of these metabolites with ecological and behavioral factors of the animal and abiotics factors. Crayfishes were collected from June/2004 until May/2005 in Gravataí, Rio Grande do Sul State, Brazil. Gills were removed and separated in anterior and posterior parts for determination of the levels of glycogen, proteins and lipids. The results were analyzed with ANOVA followed by Bonferroni test. For the comparision between males and females and anterior and posterior gills was used the two-way ANOVA test. Both tests were made with a significant level of 0.05 in the Statistical Package for the Social Sciences (SPSS-11.5) software. The results showed a bigger consumption of the glycogen and lipids in the males in relation to the females for anterior gills. This pattern can be related to the agonist behaviors of the males and the increase of the activity of exploration of the environment mainly in search of reproductive partners. The gills of P. varicosus act in different way in relation to its position (anterior and posterior) and sex, showing a clear seasonal variation. The storage and the consumption of the metabolites in each season differ between the sexes and the localization of the gills. These differences can be occurring due to environmental factor, behavioral or the addition of both of these factors.A literatura especializada tem demonstrado, em Decapoda, que as brânquias anteriores estão morfologicamente e fisiologicamente adaptadas a trocas de gases e respiração; já as posteriores são especializadas para osmorregulação. Este trabalho tem como objetivo analisar as variações sazonais do metabolismo intermediário das brânquias de P. varicosus, relacionando a variação destes metabólicos com fatores ecológicos e comportamentais do animal e fatores abióticos. Os lagostins foram coletados de Junho/2004 a Maio/2005 em Gravataí, Rio Grande do Sul, Brasil. As brânquias foram removidas e separadas as anteriores das posteriores para a determinação dos níveis de glicogênio, proteínas e lipídios. Ao compararmos os sexos, observa-se que as brânquias anteriores apresentam um comportamento diferencial ao longo do ano; padrão semelhante foi encontrado para as posteriores quando considerados os níveis de glicogênio, proteínas e lipídios. Foi observada também, uma variação na composição bioquímica das brânquias anteriores e posteriores entre as estações. Os resultados mostram um maior consumo de glicogênio e lipídios nos machos em relação às fêmeas somente para brânquias anteriores. Esta resposta pode estar relacionada a comportamentos agonistas dos machos e ao aumento da atividade de exploração do meio ambiente principalmente em busca de parceiras reprodutivas. As brânquias de P. varicosus atuam de maneira diferente quanto a sua posição (anterior e posterior) e quanto ao sexo; apresentando clara variação sazonal. O armazenamento e o consumo dos metabólitos em cada estação diferem tanto entre os sexos e quanto à localização das brânquias, tais diferenças podem estar ocorrendo por fatores ambientais, comportamentais ou pela soma destes fatores.

A CAG repeat threshold for therapeutics targeting somatic instability in Huntington's disease

The Huntington's disease mutation is a CAG repeat expansion in the huntingtin gene that results in an expanded polyglutamine tract in the huntingtin protein. The CAG repeat is unstable and expansions of hundreds of CAGs have been detected in Huntington's disease post-mortem brains. The age of disease onset can be predicted partially from the length of the CAG repeat as measured in blood. Onset age is also determined by genetic modifiers, which in six cases involve variation in DNA mismatch repair pathways genes. Knocking-out specific mismatch repair genes in mouse models of Huntington's disease prevents somatic CAG repeat expansion. Taken together, these results have led to the hypothesis that somatic CAG repeat expansion in Huntington's disease brains is required for pathogenesis. Therefore, the pathogenic repeat threshold in brain is longer than (CAG)40, as measured in blood, and is currently unknown. The mismatch repair gene MSH3 has become a major focus for therapeutic development, as unlike other mismatch repair genes, nullizygosity for MSH3 does not cause malignancies associated with mismatch repair deficiency. Potential treatments targeting MSH3 currently under development include gene therapy, biologics and small molecules, which will be assessed for efficacy in mouse models of Huntington's disease. The zQ175 knock-in model carries a mutation of approximately (CAG)185 and develops early molecular and pathological phenotypes that have been extensively characterized. Therefore, we crossed the mutant huntingtin allele onto heterozygous and homozygous Msh3 knockout backgrounds to determine the maximum benefit of targeting Msh3 in this model. Ablation of Msh3 prevented somatic expansion throughout the brain and periphery, and reduction of Msh3 by 50% decreased the rate of expansion. This had no effect on the deposition of huntingtin aggregation in the nuclei of striatal neurons, nor on the dysregulated striatal transcriptional profile. This contrasts with ablating Msh3 in knock-in models with shorter CAG repeat expansions. Therefore, further expansion of a (CAG)185 repeat in striatal neurons does not accelerate the onset of molecular and neuropathological phenotypes. It is striking that highly expanded CAG repeats of a similar size in humans cause disease onset before 2 years of age, indicating that somatic CAG repeat expansion in the brain is not required for pathogenesis. Given that the trajectory for somatic CAG expansion in the brains of Huntington's disease mutation carriers is unknown, our study underlines the importance of administering treatments targeting somatic instability as early as possible

Cigarette smoke extract profoundly suppresses TNFα-mediated proinflammatory gene expression through upregulation of ATF3 in human coronary artery endothelial cells

Endothelial dysfunction caused by the combined action of disturbed flow, inflammatory mediators and oxidants derived from cigarette smoke is known to promote coronary atherosclerosis and increase the likelihood of myocardial infarctions and strokes. Conversely, laminar flow protects against endothelial dysfunction, at least in the initial phases of atherogenesis. We studied the effects of TNFα and cigarette smoke extract on human coronary artery endothelial cells under oscillatory, normal laminar and elevated laminar shear stress for a period of 72 hours. We found, firstly, that laminar flow fails to overcome the inflammatory effects of TNFα under these conditions but that cigarette smoke induces an anti-oxidant response that appears to reduce endothelial inflammation. Elevated laminar flow, TNFα and cigarette smoke extract synergise to induce expression of the transcriptional regulator activating transcription factor 3 (ATF3), which we show by adenovirus driven overexpression, decreases inflammatory gene expression independently of activation of nuclear factor-κB. Our results illustrate the importance of studying endothelial dysfunction in vitro over prolonged periods. They also identify ATF3 as an important protective factor against endothelial dysfunction. Modulation of ATF3 expression may represent a novel approach to modulate proinflammatory gene expression and open new therapeutic avenues to treat proinflammatory diseases

Epigenetic regulation of F2RL3 associates with myocardial infarction and platelet function

DNA hypomethylation at the F2RL3 (F2R like thrombin or trypsin receptor 3) locus has been associated with both smoking and atherosclerotic cardiovascular disease; whether these smoking-related associations form a pathway to disease is unknown. F2RL3 encodes protease-activated receptor 4, a potent thrombin receptor expressed on platelets. Given the role of thrombin in platelet activation and the role of thrombus formation in myocardial infarction, alterations to this biological pathway could be important for ischemic cardiovascular disease. METHODS: We conducted multiple independent experiments to assess whether DNA hypomethylation at F2RL3 in response to smoking is associated with risk of myocardial infarction via changes to platelet reactivity. Using cohort data (N=3205), we explored the relationship between smoking, DNA hypomethylation at F2RL3, and myocardial infarction. We compared platelet reactivity in individuals with low versus high DNA methylation at F2RL3 (N=41). We used an in vitro model to explore the biological response of F2RL3 to cigarette smoke extract. Finally, a series of reporter constructs were used to investigate how differential methylation could impact F2RL3 gene expression. RESULTS: Observationally, DNA methylation at F2RL3 mediated an estimated 34% of the smoking effect on increased risk of myocardial infarction. An association between methylation group (low/high) and platelet reactivity was observed in response to PAR4 (protease-activated receptor 4) stimulation. In cells, cigarette smoke extract exposure was associated with a 4.9% to 9.3% reduction in DNA methylation at F2RL3 and a corresponding 1.7-(95% CI, 1.2–2.4, P=0.04) fold increase in F2RL3 mRNA. Results from reporter assays suggest the exon 2 region of F2RL3 may help control gene expression. CONCLUSIONS: Smoking-induced epigenetic DNA hypomethylation at F2RL3 appears to increase PAR4 expression with potential downstream consequences for platelet reactivity. Combined evidence here not only identifies F2RL3 DNA methylation as a possible contributory pathway from smoking to cardiovascular disease risk but from any feature potentially influencing F2RL3 regulation in a similar manner

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy