Lysine acetyltransferases (KATs) and lysine deacetylases (KDACs) are known to cooperate with the glucocorticoid receptor (GR) to regulate transcription. The current model of GR-mediated transcription classifies KATs as coactivators as they acetylate histones to form an open chromatin conformation and casts KDACs as corepressors that deacetylate histones and condense chromatin. Our recent studies have challenged this long-standing model. In the current study, we show that KDACs act as versatile coregulators, facilitating both the onset and maintenance of GC-induced transcriptional activation and repression. Through siRNA depletion studies, we define KDAC1 as the predominant Class I KDAC for efficient transactivation of a majority of the GR-target genes tested. KDACs 1 and 2 co-operate with each other to activate and repress a few target genes, however KDAC2 alone is not sufficient for activation or repression of the genes, thus questioning the functional redundancy of KDACs 1 and 2. Additionally, we found that there is a unique population of KDAC2 that does not associate with KDAC1 in our cell line. Through a series of siRNA depletion studies, steroid receptor coactivator proteins (SRCs) were shown to be dispensable for GC-induced gene activation and SRC2 was not required for Dex-induced transcriptional repression. We performed ChIP assays to address the mechanism by which Class I KDACs facilitate transactivation and transrepression. At GC-activated genes we found that KDACs are constitutively present at the gene enhancers and that KDAC inhibition does not affect the binding of GR or SRC proteins to chromatin. However, KDACs do influence the histone methylation status of H3K4 at GREs of activated genes and TSSs of repressed genes. To explain the change in the methylation status of this marker, we depleted LSD1, the specific demethylase for mono- and demethylation of H3K4, and found that LSD1 action is required for GC-mediated transrepression. However it is unlikely that KDAC inhibition impairs GR transactivation through effects on LSD1. Glucocorticoid signaling regulates multiple vital biological processes. Glucocorticoids play a major role in regulating carbohydrate, protein and lipid metabolism. They increase hepatic gluconeogenesis to maintain blood glucose concentration in the fasting state. GCs also act as potent anti-inflammatory molecules, stimulate lung maturation in the developing fetus, and affect bone metabolism. Additionally, excess or deficiency of GCs can lead to a variety of psychological abnormalities, indicating their role in CNS functions. Our results indicate that pharmaceutical modulation of KDACs may impair proper glucocorticoid signaling and disrupt vital biological processes. Other steroid hormone receptors function similarly to GR in regulating gene expression and could also be impacted by KDAC inhibition, thus suggesting serious physiological implications in patients. Therefore, the possibility of endocrine modulation should be taken into account when using KDAC inhibitors in the clinic.

A Artrite idiopática juvenil (AIJ) é a artropatia crônica mais prevalente na infância e adolescência. A prevalência da síndrome metabólica, assim como da obesidade, vem apresentando um rápido aumento, atingindo todas as faixas etárias, incluindo a infância. A síndrome metabólica é caracterizada por um conjunto de riscos para doença cardiovascular e diabetes melito tipo 2, incluindo adiposidade abdominal, resistência à insulina, dislipidemias e hipertensão arterial sistêmica. Além destes componentes, a inflamação tem sido reconhecida cada vez mais como um fator importante na síndrome metabólica e obesidade, e pacientes com doenças caracterizadas por processos inflamatórios crônicos, como a AIJ, poderiam representar grupos de risco especiais. Os glicocorticoides são utilizados rotineiramente no controle da inflamação da artrite idiopática juvenil, em doses elevadas e com uso prolongado. O uso crônico do glicocorticoide pode induzir resistência à insulina, hipertensão arterial sistêmica e obesidade, aumentando o risco de desenvolver síndrome metabólica. O presente trabalho tem como objetivo avaliar a prevalência de obesidade e síndrome metabólica em pacientes com AIJ. Em pacientes acompanhados no Serviço de Reumatologia do Hospital de Clínicas de Porto Alegre (HCPA) e Hospital da Criança Santo Antônio (complexo Santa Casa) foram observados uma prevalência de 19,7% de síndrome metabólica e 22,7% de obesidade, sem diferença entre os subtipos da doença. A obesidade foi associada com tempo de duração da doença, obesidade abdominal, pressão arterial elevada, resistência à insulina e presença de síndrome metabólica. O IMC, circunferência da cintura, triglicerídeos, baixos níveis de HDL-c, pressão arterial sistólica e diastólica, níveis séricos de insulina e resistência a insulina (HOMA-ir) mostraram associação com a SM (p<0,05). Não houve associação entre a presença de SM e dose cumulativa de glicocorticoide, atividade da doença e tempo de duração da doença. Os resultados mostram uma alta frequência de obesidade e síndrome metabólica em pacientes com AIJ, sugerindo um aumento do risco de futuras complicações cardiovasculares. e parecem ser independentes do uso de glicocorticoide. Ações de intervenção são necessárias entre os pacientes com AIJ para reduzir o excesso de peso, evitar as complicações metabólicas e fatores de risco cardiovasculares na vida adulta. / Juvenile idiopathic arthritis is the most prevalent chronic arthropathy in childhood and adolescence. The prevalence of metabolic syndrome, as well as obesity, is increasing fast, in all age groups, including the childhood. Metabolic syndrome is defined as a cluster of risk factors for cardiovascular and type 2 diabetes, including abdominal obesity, insulin resistance, dyslipidaemia and hypertension. Besides these components, inflammation has been increasingly considered as a significant component in metabolic syndrome and obesity, and patients with diseases characterized by the presence of chronic inflammation, such as JIA, could represent special groups of risk. Glucocorticoids are used routinely in the management of the inflammation of JIA, in high doses and long-term. Long-term use of the glucocorticoids can cause insulin resistance, hypertension and obesity, increasing the risk for the metabolic syndrome. The aim of the present study was to evaluate prevalence of the obesity and metabolic syndrome in patients with juvenile idiopathic arthritis (JIA). In patients followed in the Hospital de Clínicas de Porto Alegre (HCPA) and Hospital da Criança Santo Antônio (Santa Casa Complex) service of reumatology were observed a prevalence of 19.7% of metabolic syndrome and 22.7% of obese, without difference between the subtypes of the disease. Obesity was associated with disease duration, abdominal obesity, arterial hypertension, insulin resistance and presence of metabolic syndrome. BMI, waist circunference, triglycerides, low HDL-c level, systolic and diastolic BP, fasting insulin serum levels and insulin resistance (HOMA-ir) showed significant association with MetS (p<0,05). There was no correlation between the presence of metabolic syndrome and cumulative glucocorticoid dose, disease activity and duration of disease. The results showed that there were high frequencies of obesity and metabolic syndrome in JIA patients and use appears to be indeoendent of the use glucocorticoid. Intervation actions are needed among JIA patients, to decrease excess weight, metabolic complications and cardiovascular risk factors in adulthood.

Androgens are well documented as important regulators of male health, primarily in the maintenance and development of male sexual characteristics. However, a decline in circulating androgens has also been associated with co-morbidities such as obesity, cardiac disease and metabolic syndrome. Previous research has focussed upon the body wide impact of adrenal androgens, however whilst androgen receptor (AR) is abundantly expressed in the adrenal cortex of both rodents and humans, surprisingly little is known about androgen action on the adrenal cortex itself. This gap in our understanding is at least in part due to the perceived lack of suitable animal models. Rodents have largely been overlooked as a model system as their adrenals are unable to produce androgens due to lack of 17α Hydroxylase and 17, 20 lyse activity and they therefore do not have a zona reticularis. However, historical studies using castrated mice showed that removal of androgens leads to the redevelopment of an additional cortex zone known as the transient X-zone. The foetal adrenal is thought to give rise the adult adrenal cortex in human and rodents. These foetal cells are maintained for a period postnatally and regress differently depending on species and sex. In the human this zone is known as the ‘foetal zone’, and the rodent homologue termed the ‘X-zone’. The mechanisms underpinning the regression of the X-zone and its purpose and maintenance postnatally still aren’t clearly understood. To provide a comprehensive overview of androgen signalling in the adrenal cortex, multiple mouse models were utilised. First, Cre/loxP technology was used to ablate AR specifically from the adrenal cortex. Further androgen manipulation was achieved through castration (removal of androgens) and human chorionic gonadotropin (hCG) treatment (increased androgens). The initial study investigates the impacts on the male mouse adrenal. Histology analysis revealed the presence of an X-zone in all experimental cohorts following loss of AR or circulating androgens, confirmed by 20- α-hydroxysteroid dehydrogenase (20 alpha-HSD) expression. These data demonstrate that androgens signalling via AR is required for X-zone regression during puberty. However, interrogation of morphology of hCG treated cohorts revealed no phenotypic changes compared to controls, this demonstrates that hyper stimulation with androgens does not negatively impact the adrenal cortex or influence X-zone morphology. Differences in X-zone morphology and 20 alpha-HSD localization prompted cortex measurements which revealed significant differences in X-zone depth and cell density depending on ablation of AR, circulating androgens or both. This suggests that androgens and androgen receptor are working together and also independently to regulate the adrenal cortex. This result was strengthened through analysis of steroid enzyme genes and cortex markers, which revealed that normal AKR1B7 expression was absent following loss of androgens but not androgen receptor. A final part of this study examined the impacts long term androgen receptor ablation and long term castration in ageing animals. A final part of this study examined the impacts long term androgen receptor ablation and long term castration in ageing animals. These results demonstrate that following prolonged loss of androgens that there is no major disruption to the adrenal cortex. Morphology analysis and X-zone measurements revealed that X-zone regression was occurring in mice with long term castration, characterized by a reduction in size and pockets of vacuolization throughout the X-zone. This phenotype is also observed in ageing females with X-zone regression via vacuolization. These data suggest that following prolonged loss of androgens, the male adrenal is feminized and behaves as such. In contrast, AR ablation only, results in an enlarged adrenal with large spindle cell lesions and X-zone expansion confirmed by X-zone measurements. Initial experiments have demonstrated that androgens can work independently of AR to regulate the adrenal cortex. Together these data suggests that AR is required to control the appropriate action of circulating androgens in the adrenal cortex, with loss of AR resulting in off target signalling from circulating androgens in the adrenal leading to spindle cell hyperplasia, X-zone expansion and X-zone mislocation. A second set of studies were carried out to determine the role of androgen signalling in the female adrenal, specifically, if loss of AR leads to the absence of normal X-zone regression during pregnancy. To answer this question the same selective AR ablation model was used. Analysis of litters comparing observed and expected genetic distribution revealed significantly fewer females being born carrying complete ablation of adrenal AR. Morphology analysis of these mice revealed severe cortex disruption and spindle cell hyperplasia similar to that observed in mutant males. Investigation of adrenals following pregnancy revealed that X-zone regression still occurred despite loss of AR. This result shows that X-zone regression in the female is under different regulation compared to male adrenal and occurs via an androgen-independent signalling mechanism. However, loss of AR still leads to anatomical dysregulation of the adrenal cortex. AR ablation revealed changes in glucocorticoid receptor (GR) expression in the adrenal cortex. To dissect this relationship further a final study was conducted, attempting to ablate GR from the adrenal cortex also using the Cyp11a1 Cre. Initial observations of these mice revealed excessive hair loss through barbering, curved spines and stressed behaviour when monitored in the cage under normal conditions. Immunohistochemistry was used to confirm GR ablation in the adrenal cortex, however, to our surprise, GR expressing cells were not steroidogenic and thus were not targeted by the Cre recombinase. Despite no GR ablation in the adrenal, morphology analysis revealed severe disruption to the adrenal cortex. The Cyp11a1 Cre not only targets the adrenal but is expressed in the hindbrain. To determine if GR ablation in the hindbrain explains the phenotype, we next used PCR analysis interrogating hindbrain genomic DNA to determine if there was recombination of GR. Results confirmed GR recombination in the hindbrain. Due to the observation of stressed behaviour and adrenal cortex disruption, we wanted to determine if this was a result of hyperactivity of the adrenal cortex. Serum corticosterone was analysed and was elevated in these animals. These data revealed that GR ablation in the hindbrain results in adrenal cortex disruption and an elevated stress response, potentially highlighting a new model to investigate stress disorders and their impact on the hypothalamic-pituitary-adrenal axis. Together this data defines new roles for AR signalling in the adrenal cortex and the role of the hindbrain GR signalling in regulating adrenal morphology and function.

A Artrite idiopática juvenil (AIJ) é a artropatia crônica mais prevalente na infância e adolescência. A prevalência da síndrome metabólica, assim como da obesidade, vem apresentando um rápido aumento, atingindo todas as faixas etárias, incluindo a infância. A síndrome metabólica é caracterizada por um conjunto de riscos para doença cardiovascular e diabetes melito tipo 2, incluindo adiposidade abdominal, resistência à insulina, dislipidemias e hipertensão arterial sistêmica. Além destes componentes, a inflamação tem sido reconhecida cada vez mais como um fator importante na síndrome metabólica e obesidade, e pacientes com doenças caracterizadas por processos inflamatórios crônicos, como a AIJ, poderiam representar grupos de risco especiais. Os glicocorticoides são utilizados rotineiramente no controle da inflamação da artrite idiopática juvenil, em doses elevadas e com uso prolongado. O uso crônico do glicocorticoide pode induzir resistência à insulina, hipertensão arterial sistêmica e obesidade, aumentando o risco de desenvolver síndrome metabólica. O presente trabalho tem como objetivo avaliar a prevalência de obesidade e síndrome metabólica em pacientes com AIJ. Em pacientes acompanhados no Serviço de Reumatologia do Hospital de Clínicas de Porto Alegre (HCPA) e Hospital da Criança Santo Antônio (complexo Santa Casa) foram observados uma prevalência de 19,7% de síndrome metabólica e 22,7% de obesidade, sem diferença entre os subtipos da doença. A obesidade foi associada com tempo de duração da doença, obesidade abdominal, pressão arterial elevada, resistência à insulina e presença de síndrome metabólica. O IMC, circunferência da cintura, triglicerídeos, baixos níveis de HDL-c, pressão arterial sistólica e diastólica, níveis séricos de insulina e resistência a insulina (HOMA-ir) mostraram associação com a SM (p<0,05). Não houve associação entre a presença de SM e dose cumulativa de glicocorticoide, atividade da doença e tempo de duração da doença. Os resultados mostram uma alta frequência de obesidade e síndrome metabólica em pacientes com AIJ, sugerindo um aumento do risco de futuras complicações cardiovasculares. e parecem ser independentes do uso de glicocorticoide. Ações de intervenção são necessárias entre os pacientes com AIJ para reduzir o excesso de peso, evitar as complicações metabólicas e fatores de risco cardiovasculares na vida adulta. / Juvenile idiopathic arthritis is the most prevalent chronic arthropathy in childhood and adolescence. The prevalence of metabolic syndrome, as well as obesity, is increasing fast, in all age groups, including the childhood. Metabolic syndrome is defined as a cluster of risk factors for cardiovascular and type 2 diabetes, including abdominal obesity, insulin resistance, dyslipidaemia and hypertension. Besides these components, inflammation has been increasingly considered as a significant component in metabolic syndrome and obesity, and patients with diseases characterized by the presence of chronic inflammation, such as JIA, could represent special groups of risk. Glucocorticoids are used routinely in the management of the inflammation of JIA, in high doses and long-term. Long-term use of the glucocorticoids can cause insulin resistance, hypertension and obesity, increasing the risk for the metabolic syndrome. The aim of the present study was to evaluate prevalence of the obesity and metabolic syndrome in patients with juvenile idiopathic arthritis (JIA). In patients followed in the Hospital de Clínicas de Porto Alegre (HCPA) and Hospital da Criança Santo Antônio (Santa Casa Complex) service of reumatology were observed a prevalence of 19.7% of metabolic syndrome and 22.7% of obese, without difference between the subtypes of the disease. Obesity was associated with disease duration, abdominal obesity, arterial hypertension, insulin resistance and presence of metabolic syndrome. BMI, waist circunference, triglycerides, low HDL-c level, systolic and diastolic BP, fasting insulin serum levels and insulin resistance (HOMA-ir) showed significant association with MetS (p<0,05). There was no correlation between the presence of metabolic syndrome and cumulative glucocorticoid dose, disease activity and duration of disease. The results showed that there were high frequencies of obesity and metabolic syndrome in JIA patients and use appears to be indeoendent of the use glucocorticoid. Intervation actions are needed among JIA patients, to decrease excess weight, metabolic complications and cardiovascular risk factors in adulthood.

Este estudo investigou se o tratamento com glicocorticoide durante a gestação altera o metabolismo energético, hormonal e molecular materno, a função das ilhotas pancreáticas e mudanças correlativas sobre miRNAs. Foram utilizadas 80 ratas dividas em dois grupos de 40 animais, sendo um grupo destinado para envelhecimento até um ano após o desmame da prole, e o seguinte grupo destinado para experimentação no 20º dia de gestação, ambos dispostos em: CTL - controle, CTL-Dex - controle tratadas com dexametasona por 6 dias, P - prenhes e P-Dex - prenhes tratadas com dexametasona do 14º-19º dia de gestação. A expressão de miRNA das ilhotas foram analisadas em larga escala. Os genes alvos foram rastreados em banco de dados e confirmados. Por fim, investigou-se o mecanismo de modulação da homeostasia glicêmica. Inúmeras modificações resultaram da terapia com DEXA na gestação concluindo que a associação do tratamento ao período gravídico modula positivamente membros da família miRNA-29 ocasionando um desequilíbrio na homeostasia glicêmica por meio de falha na maquinaria exocitótica em longo prazo, desencadeado pela modulação negativa de progesterona e seu receptor promovendo prejuízo no processo de remodelação da ilhota pancreática na fase final da gestação. / This study investigated whether treatment with glucocorticoids during pregnancy alters the energetic, hormonal and molecular maternal metabolism, function of pancreatic islets and correlative changes of miRNAs. Were used 80 rats divided into two groups of 40 animals, one group designed to aging up one year after weaning, and the next group destined to experimentation at 20th day of gestation, both arranged: CTL - control, CTL-Dex - control treated with dexamethasone for 6 days, P - pregnant rats and P-Dex - pregnant rats treated with dexamethasone from 14th to 19th day of pregnancy. Pancreatic islets were collected for large-scale analysis of miRNA expression. The target genes were screened and confirmed by qPCR. Finally it was investigated the mechanism of modulation of glucose homeostasis through qPCR and Western Blot. We can be observed numerous changes resulting from therapy with DEXA in pregnancy concluded that the association of treatment to the pregnancy period modulates members of the miRNA-29 family causing an imbalance in glucose homeostasis through long-term failure in exocytotic machinery, triggered by the downregulation of the progesterone and its receptor promoting injury in the pancreatic islet remodeling process in late pregnancy.

Made available in DSpace on 2015-03-26T13:46:43Z (GMT). No. of bitstreams: 1 texto completo.pdf: 610406 bytes, checksum: ebad9c00b1406351285da383f10f132c (MD5) Previous issue date: 2004-05-14 / Osteoporosis is a disease characterized by low bone mass and deterioration of the microarchitecture of the skeleton, leading to an accentuated bone fragility and a consequent increase in the risk of fractures. Nowadays osteoporosis is being considered one of the largest and more preoccupying health problems in the world, which strikes men and women. An animal model with mice (Rattus norvegicus) is being used because it allows the access to information on the quality and bone structure that otherwise would not be obtained in patients of clinical selection, being therefore fundamental agents to accomplish an effective and safe measurement of the bone quality. The proposal of this model is to cause osteoporosis through castration, glucocorticoid administration, or the association of both, in males and females, and to evaluate that moment the disease starts. For the accomplishment of the experiment 192 adult mice were used (96 males and 96 females). They were divided in eight groups with 24 animals in each: group I - male control; group II - castrated males; group III - males with glucocorticoid therapy; group IV - castrated males with glucocorticoid therapy; group V - female control; group VI - castrated females; group VII - females with glucocorticoid therapy; group VIII - castrated females with glicocorticóide therapy. The collections took place to the 14, 28, 42 and 56 days after beginning of the administrating glucocorticoid in all the groups. It was performed plasmatic analysis of calcium, phosphorus and total proteins; quantitative analysis of calcium, phosphorus and magnesium of the humerus; flexing biomechanic test in shinbone and compression biomechanic test in lumbar vertebra (L5). Comparing the obtained results, all the experimental groups presented normal plasmatic concentrations of calcium:phosphorus (1:1 to 2:1) and bone concentrations of calcium:phosphorus (2:1) inferior to the normal rate, except for the control groups. In regarding to the biomechanic tests with males, the group IV showed smaller resistance to bone fracture, following by the group III and the group II when compared to the control group. In the groups of females it was verified that the group VI had a minimum bone loss, indicated mainly by the unbalance of the concentration of calcium:phosphorus in the bone and by the reduction of the rigidity observed in the biomechanic tests. On the other hand, the groups VII and VIII, presented inadequate bone concentration of calcium:phosphorus and bone fragility, which was observed in the flexing and compression tests, considering that the group VII presented minor rigidity average and the group VIII smaller resistance to fracture vertebra L5 and in shinbone compared to the control group. / A osteoporose é uma doença caracterizada por baixa massa óssea e deterioração da microarquitetura do esqueleto, levando a uma acentuada fragilidade óssea e a um conseqüente aumento do risco de fraturas. Atualmente considera-se a osteoporose como um dos maiores e mais preocupantes problemas de saúde do mundo, que atinge homens e mulheres. O modelo animal com ratos (Rattus norvegicus) está sendo utilizado porque permite o acesso a informações sobre a qualidade e estrutura ósseas que não seriam obtidas em pacientes de triagem clínica, sendo portanto agentes fundamentais para se realizar uma mensuração eficaz e segura da qualidade óssea. A proposta deste modelo é estabelecer a osteoporose seja por meio da castração, ou da administração de glicocorticóide, ou ainda, pela associação da castração com a administração de glicocorticóide, tanto em machos como em fêmeas, e avaliar a partir de que momento isto ocorre. Para realização do experimento foram utilizados 192 ratos adultos (96 machos e 96 fêmeas). Os animais foram divididos em oito grupos com 24 ratos em cada: grupo I machos controle; grupo II machos castrados; grupo III machos com terapia de glicocorticóide; grupo IV machos castrados com terapia de glicocorticóide; grupo V fêmeas controle; grupo VI fêmeas castradas; grupo VII fêmeas com terapia de glicocorticóide; grupo VIII fêmeas castradas com terapia de glicocorticóide. As coletas foram realizadas em todos os grupos aos 14, 28, 42 e 56 dias após o início da administração do glicocorticóide. Foram realizadas análise plasmática de cálcio, fósforo e proteínas totais; análise quantitativa de cálcio, fósforo e magnésio do úmero; teste biomecânico de flexão em tíbia e teste biomecânico de compressão em vértebra lombar (L5). Associando-se os resultados obtidos, todos os grupos experimentais apresentaram concentrações plasmáticas normais de cálcio:fósforo (1:1 a 2:1) e concentrações ósseas de cálcio:fósforo (2:1) inferiores ao normal, com exceção dos grupos controle. Com relação aos testes biomecânicos nos machos, o grupo IV se apresentou com menor resistência a fratura óssea, seguido do grupo III e do grupo II quando comparados ao grupo controle. Sendo que nos grupos de fêmeas se constatou que o grupo VI teve uma perda óssea mínima, indicada principalmente pelo desequilíbrio da concentração óssea de cálcio:fósforo e pela redução da rigidez observada nos testes biomecânicos. Já os grupos VII e VIII, apresentaram tanto concentração óssea inadequada de cálcio:fósforo como fragilidade óssea, que foi observada nos testes de flexão e compressão, considerando que o grupo VII apresentou menor média de rigidez e o grupo VIII menor resistência a fratura tanto em vértebra L5 como em tíbia com relação ao grupo controle.

O estresse é um fenômeno conservado e observado evolutivamente, que tem como objetivo assegurar a sobrevivência do indivíduo. Porém quando o organismo perde a capacidade de se autorregular, torna-se uma ameaça. Algumas psicopatologias, como ansiedade e depressão, sugerem o envolvimento dos sistemas CRF e noradrenérgico e de níveis elevados de GCs. Avaliamos nesse trabalho algumas alterações morfofisiológicas e comportamentais decorrentes da exposição do estresse crônico imprevisível (EI) em ratos machos. Avaliados 24 h após o último estímulo estressor, os animais submetidos ao EI apresentaram níveis elevados de corticosterona plasmática, de RNAm de CRF2 e expressão de GR em regiões encefálicas (LSi e VmH e LSi, CeA, BST e PVH, respectivamente). Essas alterações morfofisiológicas foram, em parte, decorrentes da ação de GCs e de NE. Não foram observadas alterações comportamentais quanto à anedonia e ansiedade. Dessa maneira, podemos dizer que o EI utilizado nesse estudo, foi capaz de induzir algumas alterações morfofisiológicas, porém não comportamentais. / While acute stress initiates neuronal responses that prepare an organism to adapt to challenges, chronic stress may lead to maladaptative responses that could result in diseases. Evidence suggests the involvement of CRF system and high corticosterone levels in stress-related psychiatric disorders such as anxiety and major depressive disorders. The aim of this work was to investigate whether chronic unpredictable stress (CUS) could modulate de CRF system, GR expression in the CNS and behavior in male rats. Results showed an increase in corticosterone plasmatic levels, CRF2 mRNA and GR expression in specific regions of the CNS (LSi e VmH e LSi, CeA, BST e PVH, respectively), associated with the limbic system at 24 h after the last stress session. The chronic treatment with an inhibitor of GCs synthesis (metyrapone) and adrenergic receptor antagonists (atenolol and phentolamine) prevented the CUS effects in CRF2 mRNA levels and GR expression. No anxiety or depression-like behavior was observed in rats submitted to CUS. We conclude that CUS cause biochemical alterations since the increase CRF2 mRNA levels and GR expression in limbic region, but these changes were not able to cause behavioral changes.

A Artrite idiopática juvenil (AIJ) é a artropatia crônica mais prevalente na infância e adolescência. A prevalência da síndrome metabólica, assim como da obesidade, vem apresentando um rápido aumento, atingindo todas as faixas etárias, incluindo a infância. A síndrome metabólica é caracterizada por um conjunto de riscos para doença cardiovascular e diabetes melito tipo 2, incluindo adiposidade abdominal, resistência à insulina, dislipidemias e hipertensão arterial sistêmica. Além destes componentes, a inflamação tem sido reconhecida cada vez mais como um fator importante na síndrome metabólica e obesidade, e pacientes com doenças caracterizadas por processos inflamatórios crônicos, como a AIJ, poderiam representar grupos de risco especiais. Os glicocorticoides são utilizados rotineiramente no controle da inflamação da artrite idiopática juvenil, em doses elevadas e com uso prolongado. O uso crônico do glicocorticoide pode induzir resistência à insulina, hipertensão arterial sistêmica e obesidade, aumentando o risco de desenvolver síndrome metabólica. O presente trabalho tem como objetivo avaliar a prevalência de obesidade e síndrome metabólica em pacientes com AIJ. Em pacientes acompanhados no Serviço de Reumatologia do Hospital de Clínicas de Porto Alegre (HCPA) e Hospital da Criança Santo Antônio (complexo Santa Casa) foram observados uma prevalência de 19,7% de síndrome metabólica e 22,7% de obesidade, sem diferença entre os subtipos da doença. A obesidade foi associada com tempo de duração da doença, obesidade abdominal, pressão arterial elevada, resistência à insulina e presença de síndrome metabólica. O IMC, circunferência da cintura, triglicerídeos, baixos níveis de HDL-c, pressão arterial sistólica e diastólica, níveis séricos de insulina e resistência a insulina (HOMA-ir) mostraram associação com a SM (p<0,05). Não houve associação entre a presença de SM e dose cumulativa de glicocorticoide, atividade da doença e tempo de duração da doença. Os resultados mostram uma alta frequência de obesidade e síndrome metabólica em pacientes com AIJ, sugerindo um aumento do risco de futuras complicações cardiovasculares. e parecem ser independentes do uso de glicocorticoide. Ações de intervenção são necessárias entre os pacientes com AIJ para reduzir o excesso de peso, evitar as complicações metabólicas e fatores de risco cardiovasculares na vida adulta. / Juvenile idiopathic arthritis is the most prevalent chronic arthropathy in childhood and adolescence. The prevalence of metabolic syndrome, as well as obesity, is increasing fast, in all age groups, including the childhood. Metabolic syndrome is defined as a cluster of risk factors for cardiovascular and type 2 diabetes, including abdominal obesity, insulin resistance, dyslipidaemia and hypertension. Besides these components, inflammation has been increasingly considered as a significant component in metabolic syndrome and obesity, and patients with diseases characterized by the presence of chronic inflammation, such as JIA, could represent special groups of risk. Glucocorticoids are used routinely in the management of the inflammation of JIA, in high doses and long-term. Long-term use of the glucocorticoids can cause insulin resistance, hypertension and obesity, increasing the risk for the metabolic syndrome. The aim of the present study was to evaluate prevalence of the obesity and metabolic syndrome in patients with juvenile idiopathic arthritis (JIA). In patients followed in the Hospital de Clínicas de Porto Alegre (HCPA) and Hospital da Criança Santo Antônio (Santa Casa Complex) service of reumatology were observed a prevalence of 19.7% of metabolic syndrome and 22.7% of obese, without difference between the subtypes of the disease. Obesity was associated with disease duration, abdominal obesity, arterial hypertension, insulin resistance and presence of metabolic syndrome. BMI, waist circunference, triglycerides, low HDL-c level, systolic and diastolic BP, fasting insulin serum levels and insulin resistance (HOMA-ir) showed significant association with MetS (p<0,05). There was no correlation between the presence of metabolic syndrome and cumulative glucocorticoid dose, disease activity and duration of disease. The results showed that there were high frequencies of obesity and metabolic syndrome in JIA patients and use appears to be indeoendent of the use glucocorticoid. Intervation actions are needed among JIA patients, to decrease excess weight, metabolic complications and cardiovascular risk factors in adulthood.

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-06-10T12:31:17Z No. of bitstreams: 1 Solange Bezerra da Silva.pdf: 1381788 bytes, checksum: c7238a332030ad186c4380df20feeee2 (MD5) / Made available in DSpace on 2016-06-10T12:31:17Z (GMT). No. of bitstreams: 1 Solange Bezerra da Silva.pdf: 1381788 bytes, checksum: c7238a332030ad186c4380df20feeee2 (MD5) Previous issue date: 2012-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Dexamethasone is widely used in processes anti-inflammatory, immunosuppressive and in cases of pregnancy with risk of prematurity. Supraphysiological doses of dexamethasone can provide complications and affect embryogenesis. Melatonin, produced by the pineal gland, has been shown to prevent the deleterious effects of glucocorticoids. We evaluated the influence of melatonin on systemic effects of dexamethasone to pregnant rats through the following parameters: 1. Hematocrit and glucose profile, 2. Levels of progesterone and 3. Histomorphometry and histochemistry of organs. We used 20 rats divided into two groups: I - pregnant rats untreated (control), II - pregnant rats treated with dexamethasone (0.8mg/kg) lll - pregnant rats treated with melatonin (0.5 mg / kg) IV: pregnant rats treated with dexamethasone and melatonin. All treatments were initiated 10 days after confirmation of mating until the end of pregnancy. Blood was collected in the 7th, 14th and 21st days. Determination of carbohydrate was accomplished by anthrone method for reading plate. Progesterone was measured by ELISA. The liver, kidneys and adrenals were examined histochemically and morphometrically. The results showed a protection of melatonin to blood parameters (hematocrit, total RBC, total and differential leukocyte count), biochemical and hormonal. Treatment with dexamethasone caused a gradual reduction in the total number of red blood cells and anisocytosis, neutrophilia, lymphopenia and eosinopenia, and reduced plasma levels of carbohydrates on day 21 and progesterone at 14 and 21 days of gestation. No evidence of morphological and histochemical changes in the organs. Dexamethasone at a dosage of 0.8 mg / kg applied from the middle third of pregnancy produces hematological, biochemical and hormonal in rats, however, does not affect the liver, kidneys and adrenals, as to histochemical and morphometric parameters. These effects were prevented by melatonin. / Dexametasona é largamente utilizada nos processos antinflamatórios, imunossupressores e em casos de gestação com risco de prematuridade. Doses suprafisiológicas de dexametasona podem propiciar complicações e afetar a embriogênese. A melatonina, produzida pela pineal, tem demonstrado prevenir efeitos deletérios dos glicocorticóides. Assim, avaliamos a influência da melatonina sobre efeitos sistêmicos da dexametasona em ratas prenhes por meio dos seguintes parâmetros: 1. Hemograma e perfil glicídico; 2. Níveis de progesterona e 3. Histomorfometria e histoquímica de órgãos. Foram utilizadas 20 ratas divididas nos grupos: I – ratas prenhes sem tratamento (Controle); II – ratas prenhes tratadas com dexametasona (0.8mg/kg); lll - ratas prenhes tratadas com melatonina (0,5 mg/Kg); lV: ratas prenhes tratadas com dexametasona e melatonina. Todos os tratamentos foram iniciados 10 dias após confirmação do acasalamento até o final da gestação. O sangue foi coletado no 7o, 14o e 21o dia. A dosagem de carboidratos foi realizada pelo método antrona para a leitura em microplaca. A progesterona foi dosada pelo método ELISA. O fígado, rins e adrenais foram analisados histoquímica e morfometricamente. Os resultados mostraram uma proteção da melatonina para os parâmetros sanguíneos (valores de hematócrito, número total de hemácias, número total e contagem diferencial de leucócitos), bioquímicos e hormonais. O tratamento com dexametasona causou redução progressiva do número total de hemácias e anisocitose, neutrofilia, linfopenia e eosinopenia, além da redução dos níveis plasmáticos de carboidratos no 21o dia, e de progesterona aos 14 e 21 dias de gestação. Não se evidenciaram alterações morfométricas e histoquímicas nos órgãos. A dexametasona na dosagem de 0,8 mg/Kg aplicada a partir do terço médio da gestação produz alterações hematológicas, bioquímicas e hormonais em ratas, porém, não afeta o fígado, rins e adrenais, quanto aos parâmetros morfométricos e histoquímicos. Estes efeitos foram prevenidos pela melatonina.

A utilização do corticosteróide antenatal objetivando induzir artificialmente a maturação fetal e garantir a sobrevivência de neonatos críticos é bem estabelecido e rotineiramente utilizado em Medicina. Por outro lado, a utilização pós-natal de corticóide, como garantia de melhores condições clínicas do neonato, ainda figura como expressivo desafio tanto em neonatologia humana quanto veterinária. Deste modo, este estudo tem como objetivo avaliar a eficácia da corticoterapia pré ou pós-natal em cordeiros prematuros extremos na melhora da condição clínica, pulmonar, metabólica e hemodinâmica; necessidade de assistência ventilatória e na garantia de sobrevivência neonatal. Para tal, cordeiros prematuros, nascidos aos 135 dias de gestação, foram aleatoriamente alocados nos grupos: corticoterapia materna pré-natal (CORT PRÉ; n=8), corticoterapia pós-natal (CORT PÓS; n=9) e controle (CONT; n=5). A corticoterapia foi realizada com betametasona em dose única de 0,5 mg/Kg, por via de aplicação intra muscular, aos 133 dias de gestação ou aos 10 minutos após o nascimento para os grupos CORT PRÉ e CORT PÓS, respectivamente. O parto foi induzido utilizando-se o fármaco aglepristona às 49 horas prévias à data estimada para o parto. Os neonatos foram avaliados quanto ao escore Apgar, condição clínica geral (freqüência cardíaca, freqüência respiratória, tônus muscular e irritabilidade reflexa), temperatura corpórea, hemogasometria arterial, glicemia, lactatemia, concentrações séricas das enzimas antioxidantes (superoxido dismutase SOD e glutationa peroxidase GPx) e marcador do estresse oxidativo (TBARS) em 10 momentos pontuais durante os 3 dias subsequentes ao parto. Para os cordeiros destinados ao suporte ventilatório, avaliamos o tempo (em minutos) necessário para o início do protocolo ventilatório a partir do nascimento e o tempo de permanência na ventilação. Os dados foram analisados por meio de testes paramétricos e não-paramétricos, com nível de significância de 95%. As variáveis também foram submetidas ao teste de correlação de Spearman. Como resultados, observamos melhor condição de vitalidade e tônus muscular nos neonatos tratados em relação ao grupo controle. Quanto à avaliação cardiogênica, a betametasona pré-natal apresentou efeito bradicárdico, enquanto a administração pós-natal resultou em efeito taquicárdico. Tanto os resultados de frequência respiratória como temperatura corpórea foram estatisticamente superiores nos neonatos tratados em relação ao controle. Todos os cordeiros nasceram bradicárdicos e bradipneicos, com valores normais atingidos a partir de 10 minutos. Observamos hiperglicemia nos grupos tratados, com valor estatisticamente superior no grupo CORT PÓS. O valor de lactato foi estatisticamente superior no grupo CORT PÓS em relação ao controle. Quanto aos componentes do equilíbrio ácido-básico, os neonatos do grupo CORT PRÉ tiveram valores significativamente maiores de bicarbonato, enquanto menores pressões de CO2 foram observadas a partir de 60 minutos, embora sem diferença quanto ao pH e BE. Os tratamentos não determinaram alterações nos valores de PO2 e SO2. Entretanto, os diferentes protocolos corticoterápicos influenciaram no perfil hematológico neonatal, com valores significativamente maiores de hematócrito no grupo CORT PÓS, seguido pelo grupo CORT PRÉ. Observamos também atuação do tratamento pós-natal nos valores de SOD e correlação positiva com os valores de hematócrito e hemoglobina. Comparando-se o percentual de cordeiros submetidos à assistência ventilatória, verificou-se maior necessidade no grupo controle. Os neonatos do grupo CORT PRÉ permaneceram por tempo menor sob assistência ventilatória, em relação ao grupo controle Com base nos resultados obtidos, concluímos que a corticoterapia pós-natal ou pré-natal favorece a condição clínica neonatal (vitalidade, tônus muscular e funções vitais), a função pulmonar (trocas gasosas e compensação aos desequilíbrios ácido-básicos) e a atividade metabólica (controle glicêmico). O tratamento pós-natal aumentou a atividade da enzima SOD, reduzindo os riscos de danos pulmonares. Ainda, o tratamento com betametasona pós-natal ou materna pré-natal diminui a necessidade de assistência ventilatória em cordeiros prematuros extremos / The use of corticosteroid aiming artificially fetal lung maturation and survival of critical neonates is used as a routine in medicine. On the other hand, the postnatal steroid therapy used to improve clinical conditions of the newborn, It\'s still a therapeutic challenge both in human as veterinary neonatology. Thus, the aims this study is to assess the effectiveness of corticosteroid, used in the pre or postnatal period, in extremely preterm lambs to improve clinical, pulmonary, metabolic and hemodynamic condition; the need for ventilatory support and neonatal survival rate. For it, preterm lambs, born with 135 days of gestation, were randomly allocated into three groups: prenatal maternal corticosteroid therapy (CORT PRE; n = 8), postnatal corticosteroid therapy (CORT POST; n = 9) and control (CONT; n = 5). The steroid therapy was performed with betamethasone in a single dose of 0.5 mg/ kg, by intramuscular route of administration, at 133 days of pregnancy our after 10 minutes from the birth in the groups CORT PRÉ and CORT PÓS, respectively. The labor was induced with aglepristone administrated 49 hours prior to the estimated date of birth. Newborns were assessed by Apgar score, general medical condition (heart rate, respiratory rate, muscle tone and reflex irritability), body temperature, blood gas analysis, blood glucose, blood lactate concentration, serum concentrations of antioxidant enzymes (superoxide dismutase - SOD and glutathione peroxidase - GPx) and marker of oxidative stress (TBARS). The assessments were performed in 10 moments during the three days from delivery. For ventilated newborns, we assessed the needed time (in minutes) between birth and the beginning of ventilatory protocol, as well as length of stay on ventilatory support. Data were analyzed using parametric and nonparametric tests, with 95% of significance level. The variables were assessed from Spearman correlation test. As results, we noted better condition of vitality and muscle tone in newborns treated when compared with control group. Regarding cardiogenic values, antenatal betamethasone resulted in bradycardic effect, while its postnatal administration was related with tachycardia. Both results of respiratory and body temperature rates were significantly higher in newborns treated compared to the control. All lambs born whith bradycardia and bradypnea, reached normal values from 10 minutes of life. Hyperglycemia was observed in the treated groups, with statistically higher values in CORT PÓS group. The lactate value was statistically higher in CORT PÓST group compared to the control. Concerning the components of the acid-base balance, the CORT PRÉ showed significantly higher values of bicarbonate, while lower pressures of CO2 were observed from 60 minutes, although there were no differences in pH and BE values. The treatments did not determine changes in PO2 and SO2 values. However, the different protocols of steroid therapy influenced on neonatal blood profile, with significantly higher hematocrit values in CORT POST group, followed by CORT PRÉ. We also observed influence of postnatal treatment in SOD values as well as positive correlation between SOD and the hematocrit and hemoglobin values. Comparing the percentage of lambs submitted to mechanical ventilation, there were most ventilated neonates in the control group. Lower ventilation time was observed in the CORT PRÉ group. Then we conclude that, the postnatal or antenatal steroids improve neonatal clinical condition (vitality, muscle tone and vital functions), lung function (gas exchange and compensation to acid-base imbalances) and metabolic activity (glycemic control). The postnatal treatment increased the activity of SOD by reducing the risks of pulmonary damage. Moreover, treatment with postnatal betamethasone or prenatal maternal reduces the need for mechanical ventilation in extremely preterm lambs