11 |
Avaliação dos efeitos da exposição ambiental paterna no fenótipo da prole de camundongos Swiss. / Avaliação dos efeitos da exposição ambiental paterna no fenótipo da prole de camundongos Swiss.Hoffmann, Lucas Barbosa 22 November 2018 (has links)
É crescente o interesse nos efeitos que o ambiente parental exerce sobre o fenótipo da prole, a chamada herança epigenética. Tem sido mostrado que essa herança ocorre especialmente para efeitos de plasticidade do desenvolvimento, os quais derivam de alteração ambiental durante o desenvolvimento parental. Dentre os estudados realizados em camundongos, várias estratégias ambientais foram abordadas, como o estresse durante a infância e o enriquecimento ambiental, com a avaliação da prole em relação a parâmetros comportamentais, fisiológicos e moleculares. De modo a estudar o fenômeno, o presente trabalho investigou, em camundongos Swiss machos, os efeitos de um estresse durante a infância, a Privação Materna em PND 9, com avaliação de comportamentos exploratório (Campo Aberto), do tipo ansioso (Labirinto em Cruz Elevado), depressivo (Nado Forçado) e relacionados ao álcool (Condicionamento Condicionado por Lugar e Sensibilização Comportamental), e, numa outra abordagem, do Enriquecimento Ambiental do desmame (PND 21) à idade adulta (PND 70), com avaliação de parâmetros fisiológicos diversos (peso corporal, de depósito de gordura, de baço e glândulas adrenais) e comportamentos exploratório (Campo Aberto), memória espacial (Labirinto de Barnes), dominância social (Tubo de Dominância Social), atratividade (Teste de Escolha de Parceiro), além de avaliação de corticosterona plasmática e BDNF hipocampal. A privação materna não promoveu diferenças para os parâmetros comportamentais avaliados. Optou-se pela utilização do paradigma do Enriquecimento Ambiental para investigação dos efeitos sobre o fenótipo da prole (machos e fêmeas). Foram observados nos filhotes machos resultados comportamentais opostos aos apresentados pela geração paterna. Porém, quando os filhos foram expostos a um período breve de enriquecimento durante a idade adulta, essas diferenças não foram mais encontradas. Portanto, conclui-se que o enriquecimento ambiental paterno foi capaz de gerar efeitos na prole, tornando os filhotes machos menos adaptados ao ambiente não enriquecido. / There is a growing interest in the effects of the parental environment on the offspring phenotype, the so-called epigenetic inheritance. It has been shown that this inheritance occurs especially for developmental plasticity effects, which stem from environmental changes during parental development. Studies carried out in mice have adopted several environmental strategies, such as early life stress and environmental enrichment, and the offspring have been assessed for behavioural, physiological and molecular parameters. In order to study the phenomenon, the present work investigated, in Swiss male mice, the effects of an early-life stress protocol, the Maternal Deprivation on PND 9, assessing behaviours such as exploratory (Open Field), anxiety-like (Elevated-Plus Maze), depressive-like (Forced Swim) and alcohol-related behaviours (Conditioned Place Preference and Behavioural Sensitisation) and, through a different approach, the environmental enrichment, from weaning (PND 21) to adulthood (PND 70), assessing diverse physiological parameters (body weight, fat pad weight, spleen and adrenal glands weights) and behaviours such as exploratory (Open Field), spatial memory (Barnes Maze), social dominance (Social Dominance Tube Test), attractiveness (Mate Choice Teste) as well as plasmatic corticosterone and hippocampal BDNF. The maternal deprivation did not yield any differences in the behavioural parameters assessed. The Environmental Enrichment paradigm was adopted for studying its effects on the offspring phenotype (males and females). Behavioural results were observed in the male offspring, which were the opposite of those found in the paternal generation. However, when the male offspring was exposed to a brief period of enrichment during adulthood, these differences were no longer found. Therefore, paternal environmental enrichment was able to induce effects on the offspring, turning male offspring less adapted to the non-enriched environment.
|
12 |
Environment and early life stages in fish : developmental plasticity responds to seawater changes in oxygen and temperature / Environnement et jeunes stades de vie chez le poisson : la plasticité développementale comme réponse aux contraintes hypoxiques et thermiquesCadiz Barrera, Laura 20 December 2017 (has links)
Dans le contexte du changement global, la diminution de la disponibilité en oxygène (hypoxie) combinée à la hausse de la température sont deux phénomènes particulièrement présents dans les eaux côtières vers lesquelles les larves de poissons peuvent dériver à la fin de leur développement. Il est admis que les régulations mises en oeuvre par les organismes pour faire face à leur environnement au cours des premières étapes de leur vie peuvent avoir des conséquences sur leur trajectoire de vie ultérieure (plasticité développementale). Ainsi, l'objectif principal de cette thèse était d’évaluer si des conditions d'oxygénation (40% et 100% de saturation) combinées à des conditions thermiques (15 et 20 °C) au stade larvaire, pouvaient avoir des impacts durables sur la physiologie des futurs juvéniles de bar (Dicentrarchus labrax). Nos résultats ont révélé que les retards de croissance associés à la plus basse température et à l’hypoxie au stade larvaire induisent une croissance compensatrice. De plus, les analyses des réserves hépatiques en glycogène et en lipides ont révélé que le métabolisme des juvéniles pourrait être affecté par les conditions environnementales au stade larvaire. Par ailleurs, nos données indiquent que la capacité d'extraction de l'oxygène a été affectée chez des juvéniles en raison de déformations operculaires causées par l’exposition précoce à l'hypoxie. Enfin, l'exposition précoce à l'hypoxie induit une sur-expression à long terme de gènes de l'hémoglobine de juvéniles replacés en situation d’hypoxie. Globalement, nos résultats contribuent à faire avancer les connaissances sur la façon dont les poissons marins font face aux changements climatiques actuels. / In the context of global change, decrease in oxygen availability (hypoxia) combined with rising water temperature are especially prevalent in coastal regions, towards which marine fish larvae may drift at the end of their development. It is well admitted that the physiological regulations implemented by organisms to cope with their environment during the early life stages of life can cause profound consequences in their subsequent life-history trajectory (developmental plasticity). Therefore, the main objective of this thesis was to investigate whether ecologically relevant conditions of oxygenation (40% and 100% air saturation) combined with thermic conditions (15 and 20 °C), occurring at the last stages of larval development of European sea bass (Dicentrarchus labrax) larvae, could have long-lasting impacts on juvenile physiology. Our data showed that growth depression resulting from low temperature and hypoxic conditions at larval stage induced a subsequent compensatory growth. Moreover, our analyses of hepatic glycogen and lipid stores revealed that metabolic features of juvenile could be affected by early exposure to oxygen and temperature conditions. Furthermore, our data revealed that oxygen extraction capacity was affected due to opercular deformities caused by early exposure to hypoxia. Finally, when seabass juveniles, that have been exposed to hypoxia at larval stage, were under chronic hypoxic condition they show a long-term up-regulation of hemoglobin genes. Overall, our findings contribute to make predictions of how the marine fish communities could be altered by current climate change.
|
13 |
Carryover Effects of Hydroperiod Length, Neonicotinoid Pesticide Exposure, and Predation Risk in a Pond-Breeding AmphibianThompson, Cassandra Marie 16 September 2022 (has links)
No description available.
|
14 |
Caractérisation de la voie de signalisation du récepteur des minéralocorticoïdes dans le rein foetal suite à une restriction de croissance intrautérineMailhot-Daye, Ève 12 1900 (has links)
La restriction de croissance intrautérine (RCIU) est associée à l’apparition de maladies à l’âge adulte et le phénotype de la condition pathologique peut être différent selon le sexe. Notre laboratoire a développé un modèle de RCIU chez le rat en administrant une diète faible en sodium lors du dernier tiers de la gestation entraînant une réduction de l’expansion volémique maternelle et de la perfusion utéroplacentaire. L'activité rénine et la concentration d'aldostérone plasmatique sont augmentées chez la mère et les foetus RCIU. Antérieurement, notre laboratoire a démontré une augmentation de l’expression génique et protéique rénale de la Na+-K+-ATPase-α1 uniquement chez les foetus femelles RCIU. Ainsi, nous émettons l’hypothèse que la diminution du volume circulant chez la rate gestante entraîne une augmentation et une expression différentielle, selon le sexe, des éléments de la cascade de signalisation du récepteur des minéralocorticoïdes (MR) dans les reins de foetus RCIU. L’expression des gènes est réalisée par qRT-PCR et celle des protéines par immunobuvardage de type Western. Bien que les résultats démontrent que la transcription génique de SGK1, α-ENaC et GILZ soit augmentée dans les reins de foetus RCIU, l’expression protéique de SGK1, pSGK1(Thr 256) et α-ENaC est similaire à celle des témoins. La protéine GILZ est indétectable. Pour CNKSR3, aucune différence de l’ARNm ou de la protéine n’a été observée entre les deux groupes. Par contre, même si l’expression génique du MR n’est pas différente, l’expression protéique est diminuée chez les RCIU. Aucun effet du sexe n’a été observé. En conclusion, l’augmentation d'aldostérone plasmatique chez les foetus ayant subi une RCIU stimule la transcription des gènes associés à la voie de réabsorption sodique, mais la quantité protéique demeure inchangée. Ceci suggère qu’il peut avoir des mécanismes de régulation post-transcriptionnelle ou une dégradation accélérée des protéines. Malgré la pertinence du sexe dans le développement de maladies, le sexe n’influence pas l’expression des composantes de la voie de rétention sodique chez le foetus. Il serait important de suivre cette voie en fonction de l’âge et de corréler les expressions génique et protéique avec l’apparition de maladies. / Intrauterine growth restriction (IUGR) contributes to the development of diseases in adulthood, of which some are influenced by sex. Our laboratory has developed an IUGR model in the rat by administering a low-sodium diet during the last third of gestation which leads to a reduced volume expansion and uteroplacental perfusion. Plasma renin activity (PRA) and aldosterone concentration are increased in IUGR dams and foetuses. Previously, our laboratory has shown that gene and protein expression of Na+-K+-ATPase-α1 was increased solely in female IUGR kidneys. Therefore, we hypothesize that the reduced maternal volume will result in an increase and differential expression, influenced by foetal sex, of elements from the mineralocorticoid receptor (MR) pathway. Gene expression is determined by qRT-PCR and for protein, Western blotting is performed. Although results show that gene expression of SGK1, α-ENaC and GILZ is increased in IUGR foetal kidneys, protein expression for SGK1, pSGK1 (Thr256), and α-ENaC is similar to controls. GILZ protein is not detected. For CNKSR3, no difference in mRNA or protein expression is observed between the groups. Gene expression of MR is unchanged, while its protein expression is decreased in IUGR foetuses. In conclusion, the increase in plasma aldosterone in IUGR foetuses stimulates gene transcription of several components of the sodium reabsorption pathway without affecting protein expression. These results suggest that there may be post-transcriptional regulation or a higher protein turnover. Despite the importance of biological sex in the development of disease, it did not affect the expression of elements from the sodium reabsorption pathway in the foetus. It would be important to verify this same pathway in animals of different ages to correlate gene and protein expression with the appearance of diseases.
|
15 |
Immune-to-brain communication driven by sterile lung injuryLitvin, David Gregory, Litvin 31 August 2018 (has links)
No description available.
|
16 |
Impact des glucocorticoïdes circulants sur la maturation et le fonctionnement de l'inhibition spinale GABAergique / Impact of glucocorticoids on maturation and functioning of the inhibitory transmission involving GABA neurotransmitterZell, Vivien 22 November 2013 (has links)
Les glucocorticoïdes (GC) sont des hormones stéroïdes synthétisées par les glandes surrénales. La production de ces GC est une des réponses de l’organisme pour rétablir l’homéostasie grâce à différentes actions comprenant des effets centraux sur le comportement et la douleur. C’est ce dernier qui a fait l’objet de mes travaux dans le cadre de cette thèse.Les afférences sensorielles primaires véhiculent les informations de la périphérie dans les cornes dorsales de la moelle épinière. Ces informations qui peuvent être nociceptives sont modulées par un réseau de neurones spinal avant d’être transmises et intégrées. Nous avons montré que les GC sont impliqués dans la maturation et le fonctionnement de la transmission inhibitrice faisant intervenir le neurotransmetteur GABA. Dans les cornes dorsales, cette inhibition est cruciale pour limiter les mécanismes de transmission de l’information nociceptive. / Glucocorticoids (GC) are steroid hormones synthesized in adrenals following HPA axis activation. GC production is a response of the organism to alleviate homeostasis perturbations through different actions. One of them involves central neuronal modulation of behavior and pain perception.Primary afferents convey peripheral sensory information in the dorsal horns of the spinal cord. This information can be nociceptive and are modulated by a spinal neuronal network before being transmitted and integrated. We showed that GC are implied in the maturation and functioning of the inhibitory transmission involving GABA neurotransmitter. In the dorsal horns this inhibitory transmission is of major importance, limiting the processing of nociceptive information.
|
17 |
The potential relationships between hormone biomarkers and functional and health outcomes of ageingEendebak, Robert January 2017 (has links)
Although the female menopause has been extensively characterized as a well-defined symptomatic state of oestrogen deficiency, which responds relatively well to oestrogen replacement therapy, the symptomatic state of androgen deficiency in men is poorly defined and uncertainty exists whether it responds to testosterone replacement. It has been proposed that hypothalamic-pituitary-testicular (HPT)-axis function (responsible for the production of androgens) and regulation could be viewed as a âbarometerâ of health status in older men and that potential alterations in HPT-axis function and regulation reflect subclinical and clinical deficits in function and health, which may result in an aged phenotype of human health and disease in older men. The HPT-axis constitutes a well-defined, tractable, clinically-relevant, biological system, which may permit insight into the mechanisms underlying the expression of ageing-related phenotypes of human health and disease. By using a different lens â such as the genetic background; the compensatory responses within the HPT-axis; the syndromes of androgen deficiency; the ethnic background of an individual or the life course trajectory of function and health from conception into older age â to magnify potential dysregulation in the HPT-axis will it be possible to visualize and understand the phenotypic expression of human male ageing as a gradient of functional and health outcomes. This will allow for a better understanding of the physiological mechanics underlying symptomatic expression of dysregulation in the HPT-axis.
|
Page generated in 0.0937 seconds