Gene expression and physiological changes of the Antarctic krill Euphausia superba under different hypoxia intensities

Antarctic krill (Euphausia superba) from South Georgia comprise one of the most northern and abundant krill stocks. South Georgia waters are undergoing rapid warming, as a result of climate change, which in turn could alter the oxygen concentration of the water. We investigated gene expression in Antarctic krill related to aerobic metabolism, antioxidant defence, and heat-shock response under severe (2.5% O2 saturation or 0.6 kPa) and threshold (20% O2 saturation or 4 kPa) hypoxia exposure compared to in situ levels (normoxic; 100% O2 saturation or 21 kPa). Biochemical metabolic and oxidative stress indicators complemented the genic expression analysis to detect in vivo signs of stress during the hypoxia treatments. Expression levels of the genes citrate synthase (CS), mitochondrial manganese superoxide dismutase (SODMn-m) and one heat-shock protein isoform (E) were higher in euphausiids incubated 6 h at 20% O2 saturation than in animals exposed to control (normoxic) conditions. All biochemical antioxidant defence parameters remained unchanged among treatments. Levels of lipid peroxidation were raised after 6 h of severe hypoxia. Overall, short-term exposure to hypoxia altered mitochondrial metabolic and antioxidant capacity, but did not induce anaerobic metabolism. Antarctic krill are swarming organisms and may experience short periods of hypoxia when present in dense swarms. A future, warmer Southern ocean, where oxygen saturation levels are decreased, may result in smaller, less dense swarms as they act to avoid greater levels of hypoxia.

Comparação do uso de noradrenalina, nitroprussiato e levosimendan na terapia do choque hipovolêmico: efeitos sobre a microcirculação e expressão gênica renal

Este trabalho teve como objetivo avaliar os efeitos sistêmicos, microcirculatórios assim como mudanças na expressão gênica renal, causados pela ação da noradrenalina, nitropussiato de sódio e levosimendan no tratamento do choque hemorrágico. Nesse estudo foi utilizado o modelo da câmara dorsal.Os animais foram sujeitos a choque hemorrágico e após, foram aleatoriamente divididos em quatro grupos. Os grupos foram: CTRL, recebeu apenas ringer lactato; NPS recebeu ringer lactato com nitroprussiato de sódio; NA recebeu ringer lactato com noradrenalina e LEV, recebeu ringer lactato com levosimendan. Foram avaliados parâmetros sistêmicos, assim como parâmetros microcirculatórios (comparados como percentual em relação ao momento basal). Além disso, foi avaliada a expressão gênica renal de eNOS, HIF-1α, ICAM e caspase-3. O grupo NPS apresentou uma recuperação sustentada do diâmetro arteriolar ( 89 12 %) e DCF (125 114 %) ao final do tratamento. Houve recuperação da velocidade de hemácias nos grupos CTRL e NPS. Não houve diferença em relação ao número de leucócitos aderidos e/ou rolantes ao final do tratamento. A expressão gênica renal de eNOS e caspase-3 entre os grupos não apontou diferenças, entretanto houve diferença significativa na expressão renal de HIF- 1α no grupo NA (0,65 0,08, UA) em relação ao grupo CTRL (0,44 0,06, UA) e LEV (0,45 0,06, UA). Todos os grupos tiveram uma maior expressão de ICAM (0,65 0,12; 0,7 0,12; 0,069 0,06; 0,65 0,12, UA) em relação ao grupo SHAM (0,50 0,05, UA). Ringer lactato puro ou associado com noradrenalina ou levosimendan não foram suficientes para recuperar e sustentar os parâmetros microvasculares. O tratamento com nitroprussiato de sódio foi o que apresentou os melhores resultados, com recuperação dos diâmetros arteriolar, da DCF e velocidade de hemácias.

Perfil transcricional de Bradyrhizobium elkanii SEMIA 587 in vitro e em simbiose com soja (Glycine max L. Merrill) através de microarranjo de DNA

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do exercício físico no remodelamento cardíaco de ratos espontaneamente hipertensos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antidepressivo modula o comportamento e a expressão gênica das cadeias de miosina, serca2 e fosfolambam em ratos com insuficiência aórtica?

Introduction: Aortic insufficiency (AoI), a volume overload, is characterized by the diastolic reflux of blood from the regurgitating aorta to the left ventricle. This effect results from malfunctioning aortic cusps. The main cause of AoI in developing countries is rheumatic fever, including Brazil, and valvar degeneration in developed countries. There is a strong association between cardiovascular diseases and depression. Selective serotonin reuptake inhibitors (SSRI) are one of the most prescribed antidepressants in the world. Previous studies of our laboratory showed that the utilization of a SSRI, paroxetine, improved cardiac function in rats with sub-chronic AoI and reduced the daily ingestion of hypertonic sodium (NaCl 0,3M). Cardiovascular diseases can determine behavior changes like increase of anxiety, and it is yet unknown if AoI would determine anxiety or anhedonia, incapacity of obtaining pleasure through physical or sensorial experiences. A possible target for SSRI action could be a change in the expression of enzyme isoforms that collaborate in the contractile function of the heart muscle, like the heavy chains of myosine, the sarcoplasmatic reticulum Ca2+/ATPase (SERCA) and its regulator protein, phospholamban (PLB). Objectives: Evaluation of behavior parameters for anxiety and anhedonia state and genic expression of a-myosine, b-myosine, SERCA2a and PLB in the heart tissue of rats with subchronic AoI that received treatment with an SSRI (paroxetine) for 4 weeks. Methods: Surgery to induce AoI was performed on male Wistar rats, anxiety was evaluated by the elevated plus-maze (EPM) and state of anhedonia was tested by ingestion of 2% sucrose solution. After euthanasia the heart tissue was collected and total RNA was extracted to be analyzed by the RT-qPCR method. Results: Heart fractional shortening was preserved in rats with AoI that were treated compared to rats with AoI that were not treated. There was no statistically ...

Effects of electroacupuncture on experimental periodontitis in rats

Background: Acupuncture has shown the capability of modulating the immuno-inflammatory response of the host. This study aims to evaluate the effects of electroacupuncture (EA) on ligature-induced periodontitis in rats. Methods: Thirty-two animals were divided into four groups: 1) control; 2) experimental periodontitis (EP); 3) sham-treated (EP/EA-sham); and 4) treated with EA (EP/EA). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. For EA treatment, large intestine meridian points LI4 and LI11 and stomach meridian points ST36 and ST44 were used. EA-sham was performed in off-meridian points. Animals were euthanized at day 11. Histomorphometric and microtomographic analyses were performed. Immunolabeling patterns for the receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) were assessed. Expressions of interleukin (IL)-1 beta, matrix metalloproteinase (MMP)-8, IL-6, and cyclooxygenase (COX)-2 messenger RNAs (mRNAs) were evaluated by quantitative reverse transcription-polymerase chain reaction. Data were analyzed statistically (P < 0.05, analysis of variance). Results: Histomorphometric and microtomographic analyses demonstrated that group EP/EA presented reduced alveolar bone loss when compared to group EP (P < 0.05). Reduced RANKL immunolabeling and fewer TRAP-positive multinucleated cells were observed in the EA-treated group in relation to group EP. No differences were observed in OPG expression among groups. EA treatment decreased the genic expression of IL-1 beta and MMP-8 (P < 0.05), increased the mRNA expression of IL-6 (P < 0.05), and did not modify the genic expression of COX-2 in animals with EP (P > 0.05). Conclusion: It can be concluded that EA reduced periodontal tissue breakdown and the expression of some proinflammatory mediators and a proresorptive factor in EP in rats.

Própolis na dieta de abelhas Apis mellifera L. e seu efeito no sistema imune, expressão de genes após o desafio bacteriano e detoxificação frente ao agroquímico fipronil

Pós-graduação em Zootecnia - FMVZ

Efeitos da adição do IGF-1 ou IGF-LongR3 sobre aspectos celulares e moleculares de complexos cumulus-oócito durante a maturação oocitária in vitro em bovinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos da melatonina sobre a inflamação e o estresse oxidativo tecidual de pacientes submetidos à laparoscopia cirúrgica

Pós-graduação em Anestesiologia - FMB

Impacto de andrógenos na diferenciação e atividade de osteoclastos em cultura celular

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da teneurina-2 (Ten-2) nos astrócitos do córtex cerebral de ratos adultos após lesão mecânica. Estudo imuno-histoquímico e de expressão gênica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impacto de andrógenos na diferenciação e atividade de osteoclastos em cultura celular

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da teneurina-2 (Ten-2) nos astrócitos do córtex cerebral de ratos adultos após lesão mecânica. Estudo imuno-histoquímico e de expressão gênica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Intergenic and genic sequence lengths have opposite relationships with respect to gene expression.

Eukaryotic genomes are mostly composed of noncoding DNA whose role is still poorly understood. Studies in several organisms have shown correlations between the length of the intergenic and genic sequences of a gene and the expression of its corresponding mRNA transcript. Some studies have found a positive relationship between intergenic sequence length and expression diversity between tissues, and concluded that genes under greater regulatory control require more regulatory information in their intergenic sequences. Other reports found a negative relationship between expression level and gene length and the interpretation was that there is selection pressure for highly expressed genes to remain small. However, a correlation between gene sequence length and expression diversity, opposite to that observed for intergenic sequences, has also been reported, and to date there is no testable explanation for this observation. To shed light on these varied and sometimes conflicting results, we performed a thorough study of the relationships between sequence length and gene expression using cell-type (tissue) specific microarray data in Arabidopsis thaliana. We measured median gene expression across tissues (expression level), expression variability between tissues (expression pattern uniformity), and expression variability between replicates (expression noise). We found that intergenic (upstream and downstream) and genic (coding and noncoding) sequences have generally opposite relationships with respect to expression, whether it is tissue variability, median, or expression noise. To explain these results we propose a model, in which the lengths of the intergenic and genic sequences have opposite effects on the ability of the transcribed region of the gene to be epigenetically regulated for differential expression. These findings could shed light on the role and influence of noncoding sequences on gene expression.