The role of methylation of placental glucocorticoid response gene in the association between pregnancy-related anxiety in the third trimester and birth outcomes / 中华预防医学杂志

Objective: To investigate the role of methylation of placental glucocorticoid response gene in the association between pregnancy-related anxiety in the third trimester and birth outcomes. Methods: Based on a prospective cohort study, singleton live births and their mothers from the Ma'anshan Birth Cohort Study (MABC) were included as participants in this study. The maternal pregnancy-related anxiety symptoms in the third trimester of pregnancy were evaluated by using the Pregnancy-related Anxiety Questionnaire. The neonatal birth outcomes were collected from medical records. The placental tissues from 300 pregnant women with pregnancy-related anxiety and 300 without pregnancy-related anxiety were collected to detect the methylation of FKBP5, NR3C1 and HSD11B2 genes using the Methyl Target approach. The methylation factors were extracted by exploratory factor analysis. Linear regression or logistic regression models were used to analyze the association between pregnancy-related anxiety in the third trimester, methylation factor scores, and birth outcomes. The mediating role of methylation factors in the association between pregnancy-related anxiety in the third trimester and birth outcomes was analyzed by using the Process procedure. Results: The mean age of 2 833 pregnant women was (26.60±3.60) years old. After adjusting for confounding factors, pregnancy-related anxiety in the third trimester increased the risk of small-for-gestational-age (OR=1.32, 95%CI:1.00-1.74). A total of 5 methylation factors were extracted, and the factor 5 was loaded with FKBP5 CpGs 18-21. Pregnancy-related anxiety in the third trimester was negatively correlated with the factor 5 (β=-0.24,95%CI:-0.44--0.05). The factor 5 was positively correlated with the gestational age (β=0.17, 95%CI:0.06-0.27). In addition, the factor 2 (β=0.02,95%CI:0.00-0.04) and factor 3 (β=0.03,95%CI:0.01-0.05) were positively correlated with 5-min Apgar score after delivery. However, this study did not found the mediating role of the scores of the factor characterized by FKBP5 in the relationship between pregnancy-related anxiety and birth outcomes. Conclusion: Pregnancy-related anxiety in the third trimester may reduce the methylation level of FKBP5 CpGs 18-21 in placental tissues and is associated with the risk of small-for-gestational-age.

Chronic psychological stress exacerbates aortic medial calcification via glucocorticoids / 生理学报

Chronic psychological stress can promote vascular diseases, such as hypertension and atherosclerosis. This study aims to explore the effects and mechanism of chronic psychological stress on aortic medial calcification (AMC). Rat arterial calcification model was established by nicotine gavage in combination with vitamin D3 (VitD3) intramuscular injection, and rat model of chronic psychological stress was induced by humid environment. Aortic calcification in rats was evaluated by using Alizarin red staining, aortic calcium content detection, and alkaline phosphatase (ALP) activity assay. The expression levels of the related proteins, including vascular smooth muscle cells (VSMCs) contractile phenotype marker SM22α, osteoblast-like phenotype marker RUNX2, and endoplasmic reticulum stress (ERS) markers (GRP78 and CHOP), were determined by Western blot. The results showed that chronic psychological stress alone induced AMC in rats, further aggravated AMC induced by nicotine in combination with VitD3, promoted the osteoblast-like phenotype transformation of VSMCs and aortic ERS activation, and significantly increased the plasma cortisol levels. The 11β-hydroxylase inhibitor metyrapone effectively reduced chronic psychological stress-induced plasma cortisol levels and ameliorated AMC and aortic ERS in chronic psychological stress model rats. Conversely, the glucocorticoid receptor agonist dexamethasone induced AMC, promoted AMC induced by nicotine combined with VitD3, and further activated aortic ERS. The above effects of dexamethasone could be inhibited by ERS inhibitor 4-phenylbutyrate. These results suggest that chronic psychological stress can lead to the occurrence and development of AMC by promoting glucocorticoid synthesis, which may provide new strategies and targets for the prevention and control of AMC.

Resposta endócrina à contenção física e isolamento em papagaios-verdadeiros / Endocrine response to physical restraint and isolation in blue-fronted parrots

O objetivo deste trabalho foi analisar a resposta dos papagaios-verdadeiros aos procedimentos de contenção e separação física por método não invasivo, como a dosagem das concentrações de metabólitos de glicocorticoides nas excretas. Para tanto, foram utilizadas 24 aves, 17 machos e sete fêmeas, inicialmente mantidas em viveiros amplos e adjacentes, separadas por sexo. Após captura e contenção de três minutos, 13 aves voltaram para os viveiros coletivos e 11 foram alojadas em gaiolas individuais no mesmo recinto dos viveiros, de modo a permitir que as aves isoladas mantivessem contato visual e auditivo com as demais. Para avaliar se os animais responderiam de maneira diferente quando fisicamente isolados ou em grupo, amostras de excretas foram coletadas sequencialmente em intervalos de três horas durante 24 horas para avaliação dos metabólitos de glicocorticoides por enzimaimunoensaio. Não houve efeito significativo de sexo (P=0,5850), tratamento (P=0,6805) e tempo (P=0,2293), e as concentrações de metabólitos de glicocorticoides mantiveram-se dentro da variação diurna esperada para esta espécie. Portanto, ambos os grupos responderam endocrinologicamente de forma semelhante e o estresse de captura e separação física não foi significativo para as aves.(AU)

The aim of this study was to evaluate the response of blue-fronted parrots to restraint procedures and separation by non-invasive methods such as measurement of glucocorticoid metabolites in droppings. For this, we utilized 24 birds, 17 males and 7 females, initially kept in large adjacent aviaries, separated by sex. After capture and 3 minutes of manual contention, by random, 13 birds returned to the aviary and 11 animals were housed in individual cages in the same facility of the aviaries allowing the maintenance of auditory and visual contact between them. In order to evaluate if the physically isolated birds isolated or in groups would react in different ways, all droppings samples were collected at 3-hours intervals during 24 hours to evaluation of excreted glucocorticoid metabolites by enzimeimmunoassay. There were no significant effects of sex (P=0.5850), treatment (P=0.6805) and time (P=0.2293) and the glucocorticoid metabolites concentrations were within the diurnal range expected for this specie. Therefore, the endocrine response of both groups was similar and stress of capture and physical separation was not significant for the birds.(AU)

Fecal cortisol metabolites as indicators of stress in crab-eating-fox (Cerdocyoun thous) in captivity / Metabolitos fecais de cortisol como indicadores de estresse em cachorro-do-mato (Cerdocyoun thous) em cativeiro

Blood samples collection is a common method in biological research using domestic animals. However, most blood sampling techniques are complicated and highly invasive and may therefore not be appropriate for wildlife animals in research concerning stress. Thus, a non-invasive method to measure steroid hormones is critically needed. The first goal of this study was to determine how glucocorticoids concentrations are impacted by translocation and reproductive activity in crab-eating-fox (Cerdocyoun thous) in captivity. The physiological relevance of fecal glucocorticoid metabolites was further validated by demonstrating: (1) The translocation of a male to a females enclosure resulted in a 3.5-fold increase compared to baseline concentrations, (2) changes in adrenocortical activity, as reflected in concentrations of fecal cortisol metabolites during reproduction, gestation and lactation in females foxes, indicating that social interactions resulted in large increases of fecal glucocorticoids metabolites during the reproductive season. From these findings we conclude that fecal samples can be used for the non-invasive assessment of adrenocortical status in crab-eating-fox...

Coleta de sangue é um método comumente utilizado na pesquisa com animais domésticos. Entretanto, a técnica de coleta de sangue torna-se complicada e altamente invasiva em animais selvagens devido ao estresse, tornando-a inapropriada para pesquisa. Dessa maneira, métodos não invasivos utilizados na mensuração de hormonios tornam-se necessários. O principal objetivo deste estudo foi determinar como as concentrações de glucocorticoides atuam durante a translocação e a atividade reprodutiva de cachorro-do-mato (Cerdocyoun thous) em cativeiro. A relevância fisiológica da análise de metabolitos fecais de glucocorticoides pôde ser validada pela demonstração de que: (1) A translocação de machos para o recinto de fêmeas resultou em um aumento de 3.5 vezes comparado a concentrações basais; (2) mudanças na atividade adrenocortical, como reflexo das concentrações de metabolitos de cortisol fecal durante a reprodução, gestação e lactação em femeas de cachorro-do-mato (Cerdocyoun thous), indicaram que interações sociais resultaram em aumento de glucocorticoides fecais durante a época reprodutiva. Com estas constatações podemos concluir que amostras fecais podem ser usadas para acesso não invasivo da atividade adrenocortical em cachorro-do-mato (Cerdocyoun thous)...

Anatomopathology of the Superstructure of the Stapes in Patients with Otosclerosis

Introduction Otosclerosis is a disease that causes bone resorption and deposition in the auditory structures, leading to deafness. Many studies have evaluated the histopathology of the stapes footplate in this disease (osteoblasts, osteoclasts, vascular proliferation, fibroblasts, and histiocytes), but we found no studies in the literature involving the histology of the superstructure of the stapes. Objectives To perform an analysis under optical microscopy of histopathologic findings of the superstructure of the stapes from patients with otosclerosis. Methods A contemporary cross-sectional cohort study of pathology analysis of superstructures of the stapes of patients with otosclerosis. Results Fifteen superstructures of stapes in patients with otosclerosis operated in our service and four stapes of cadavers used for dissection (controls) were evaluated. No areas of bone resorption or deposition or presence of osteoclasts and osteoblasts in the superstructure of the stapes were found. However, we found in themore distal portions of the crura areas with prominent cementitious lines and woven bone, which was different than the mature trabecular bone found in the head of the stapes or in the controls. Conclusion There were histologic changes in the superstructure of the stapes in patients with otosclerosis operated in our service. .

Disruption of glucose tolerance caused by glucocorticoid excess in rats is partially prevented, but not attenuated, by arjunolic acid.

Arjunolic acid (AA) obtained from plants of the Combretaceae family has shown anti-diabetic effects. Here, we analyzed whether the diabetogenic effects of dexamethasone (DEX) treatment on glucose homeostasis may be prevented or attenuated by the concomitant administration of AA. Adult Wistar rats were assigned to the following groups: vehicle-treated (Ctl), DEX-treated (1 mg/kg body weight intraperitoneally for 5 days) (Dex), AA-treated (30 mg/kg body weight by oral gavage twice per day) (Aa), AA treatment previous to and concomitant to DEX treatment (AaDex), and AA treatment after initiation of DEX treatment (DexAa). AA administration significantly ameliorated (AaDex) (P>0.05), but did not attenuate (DexAa), the glucose intolerance induced by DEX treatment. AA did not prevent or attenuate the elevation in hepatic glycogen and triacylglycerol content caused by DEX treatment. All DEX-treated rats exhibited hepatic steatosis that seemed to be more pronounced when associated with AA treatment given for a prolonged period (AaDex). Markers of liver function and oxidative stress were not significantly altered among the groups. Therefore, AA administered for a prolonged period partially prevents the glucose intolerance induced by DEX treatment, but it fails to produce this beneficial effect when given after initiation of GC treatment. Since AA may promote further hepatic steatosis when co-administered with GCs, care is required when considering this phytochemical as a hypoglycemiant and/or insulin-sensitizing agent.

Cortisol: the villain in Metabolic Syndrome? / Cortisol: o vilão na Síndrome Metabólica?

Objective This article reviews the state of the art regarding the association between glucocorticoid actions and both obesity and insulin resistance, two main features of the metabolic syndrome. Methods A methodological assessment of the literature on PubMed and SciELO databases was conducted by using the following terms: stress, metabolic syndrome, glucocorticoids, obesity, insulin resistance, hypothalamic-pituitary-adrenal-axis and 11β-hydroxysteroid dehydrogenase. Results Chronic stress, mainly through hypothalamic-pituitary-adrenal axis dysregulation, promotes the accumulation of visceral fat. Reciprocally, obesity promotes a systemic low-grade inflammation state, mediated by increased adipokine secretion, which can chronically stimulate and disturb stress system. This vicious cycle, probably initiated by visceral adipose tissue dysfunction, might be the trigger for the development of metabolic syndrome. Conclusion Given the strong evidences linking glucocorticoid release, obesity and type 2 diabetes, better understanding of the mechanisms underlying this connection might be useful for prevention and treatment of the metabolic syndrome. .

Objetivo Este artigo revê o estado da arte relativamente à associação entre as ações dos glicocorticoides e a obesidade e a resistência à insulina, dois dos principais componentes da síndrome metabólica. Métodos Uma revisão da literatura nas bases de dados PubMed e SciELO foi realizada usando os seguintes termos: estresse, síndrome metabólica, glicocorticoides, obesidade, resistência à insulina, eixo hipotálamo-hipófise-suprarrenal e 11β-hidroxiesteróide desidrogenase. Resultados O estresse crônico, principalmente através da desregulação do eixo hipotálamo-hipófise-suprarrenal, promove a acumulação de gordura visceral. Reciprocamente, a obesidade promove um estado inflamatório sistêmico de baixo grau, mediado por alterações na secreção de adipocinas, que cronicamente podem estimular e perturbar o sistema de estresse. Esse círculo vicioso, provavelmente iniciado pela disfunção do tecido adiposo visceral, pode ser o mecanismo primário que conduz ao desenvolvimento da síndrome metabólica. Conclusão Um conhecimento mais aprofundado sobre os mecanismos envolvidos na associação entre a liberação de glicocorticoides, a obesidade e o diabete tipo 2 pode ser útil na prevenção e tratamento da síndrome metabólica. .

Molecular Interaction between the Glucocorticoid Receptor and MAPK Signaling Pathway: A novel link in Modulating the Anti-inflammatory Role of Glucocorticoids.

Glucocorticoids (GCs) have a broad spectrum of life-sustaining functions and play an important role in health and diseases. At pharmacologic doses, GCs are potent immunosuppressive and anti-inflammatory agents. Inflammation and its related diseases present a huge ever increasing burden on the health and disease management. A plausible link of inflammation with aging, cardiovascular diseases and cancer makes matter even worst and calls for a better understanding to resolve the mechanisms associated with the cause and cure of inflammation. Understanding the physiological and molecular interlinks is an utmost importance in designing novel therapeutic strategies in combating inflammation. Advancement in research related to the mitogen-activated protein kinase (MAPK) signaling pathway and its regulation on inflammation has open up new and promising avenues in targeting inflammation as well as understanding the anti-inflammatory property of GCs. Molecular interaction between the ligand-activated glucocorticoid receptor (GR) and the MAPK signaling at different junctions inhibit the latter and thus may account for the anti-inflammatory role of GCs. Therapeutic application of GCs in combination with the recently added class of GR modulators having greater transrepresssion over transactivation (dissociative property) might overcome the clinical side effects associated with GCs.

Maternal undernutrition and the offspring kidney: from fetal to adult life

Maternal dietary protein restriction during pregnancy is associated with low fetal birth weight and leads to renal morphological and physiological changes. Different mechanisms can contribute to this phenotype: exposure to fetal glucocorticoid, alterations in the components of the renin-angiotensin system, apoptosis, and DNA methylation. A low-protein diet during gestation decreases the activity of placental 11ß-hydroxysteroid dehydrogenase, exposing the fetus to glucocorticoids and resetting the hypothalamic-pituitary-adrenal axis in the offspring. The abnormal function/expression of type 1 (AT1R) or type 2 (AT2R) AngII receptors during any period of life may be the consequence or cause of renal adaptation. AT1R is up-regulated, compared with control, on the first day after birth of offspring born to low-protein diet mothers, but this protein appears to be down-regulated by 12 days of age and thereafter. In these offspring, AT2R expression differs from control at 1 day of age, but is also down-regulated thereafter, with low nephron numbers at all ages: from the fetal period, at the end of nephron formation, and during adulthood. However, during adulthood, the glomerular filtration rate is not altered, due to glomerulus and podocyte hypertrophy. Kidney tubule transporters are regulated by physiological mechanisms; Na+/K+-ATPase is inhibited by AngII and, in this model, the down-regulated AngII receptors fail to inhibit Na+/K+-ATPase, leading to increased Na+ reabsorption, contributing to the hypertensive status. We also considered the modulation of pro-apoptotic and anti-apoptotic factors during nephrogenesis, since organogenesis depends upon a tight balance between proliferation, differentiation and cell death.

Molecular mechanisms of glucocorticoid receptor signaling / Mecanismos moleculares de señalización del receptor de glucocorticoides

This review highlights the most recent findings on the molecular mechanisms of the glucocorticoid receptor (GR). Most effects of glucocorticoids are mediated by the intracellular GR which is present in almost every tissue and controls transcriptional activation via direct and indirect mechanisms. Nevertheless the glucocorticoid responses are tissue -and gene- specific. GR associates selectively with corticosteroid ligands produced in the adrenal gland in response to changes of humoral homeostasis. Ligand interaction with GR promotes either GR binding to genomic glucocorticoid response elements, in turn modulating gene transcription, or interaction of GR monomers with other transcription factors activated by other signalling pathways leading to transrepression. The GR regulates a broad spectrum of physiological functions, including cell differentiation, metabolism and inflammatory responses. Thus, disruption or dysregulation of GR function will result in severe impairments in the maintenance of homeostasis and the control of adaptation to stress.

Esta revisión destaca los más recientes hallazgos sobre los mecanismos moleculares del receptor de glucocorticoides (GR). La mayoría de los efectos de los glucocorticoides son mediados por los GR intracelulares presentes en casi todos los tejidos y controlan la activación transcripcional por mecanismos directos e indirectos. Las respuestas a los glucocorticoides son específicas para cada gen y tejido. Los GR se asocian en forma selectiva con ligandos producidos en la glándula adrenal, corticosteroides, en respuesta a cambios neuroendocrinos. La interacción del ligando con el GR promueve: a) la unión del GR a elementos genómicos de respuesta a glucocorticoides, modulando la transcripción; b) la interacción de monómeros del GR con otros factores de transcripción activados por otras vías, llevando a la transrepresión. El GR regula un amplio espectro de funciones fisiológicas, incluyendo la diferenciación celular y las respuestas metabólicas e inflamatorias. Así, la desregulación de la función del GR resulta en graves defectos en el mantenimiento de la homeostasis y el control de la adaptación al estrés.

Glucocorticoids, master modulators of the thymic catecholaminergic system?

There is evidence that the major mediators of stress, i.e., catecholamines and glucocorticoids, play an important role in modulating thymopoiesis and consequently immune responses. Furthermore, there are data suggesting that glucocorticoids influence catecholamine action. Therefore, to assess the putative relevance of glucocorticoid-catecholamine interplay in the modulation of thymopoiesis we analyzed thymocyte differentiation/maturation in non-adrenalectomized and andrenalectomized rats subjected to treatment with propranolol (0.4 mg·100 g body weight-1·day-1) for 4 days. The effects of β-adrenoceptor blockade on thymopoiesis in non-adrenalectomized rats differed not only quantitatively but also qualitatively from those in adrenalectomized rats. In adrenalectomized rats, besides a more efficient thymopoiesis [judged by a more pronounced increase in the relative proportion of the most mature single-positive TCRαβhigh thymocytes as revealed by two-way ANOVA; for CD4+CD8- F (1,20) = 10.92, P < 0.01; for CD4-CD8+ F (1,20) = 7.47, P < 0.05], a skewed thymocyte maturation towards the CD4-CD8+ phenotype, and consequently a diminished CD4+CD8-/CD4-CD8+ mature TCRαβhigh thymocyte ratio (3.41 ± 0.21 in non-adrenalectomized rats vs 2.90 ± 0.31 in adrenalectomized rats, P < 0.05) were found. Therefore, we assumed that catecholaminergic modulation of thymopoiesis exhibits a substantial degree of glucocorticoid-dependent plasticity. Given that glucocorticoids, apart from catecholamine synthesis, influence adrenoceptor expression, we also hypothesized that the lack of adrenal glucocorticoids affected not only β-adrenoceptor- but also α-adrenoceptor-mediated modulation of thymopoiesis.

A pilot study on hypothalamo-pituitary-adrenocortical axis in primary hyperparathyroidism.

Background & objectives: Parathormone (PTH) and calcium, both have been shown to stimulate adrenal steroidogenesis in animal models and in vitro experiments. This is attributed to structural similarity between 15-25 amino acid region of the parathyroid hormone (PTH) and 1-11 amino acid region of adrenocorticotropin (ACTH). However, there are no in vivo human data regarding the effect of PTHcalcium axis on adrenocortical function. Materials: Ten patients with primary hyperparathyroidism underwent evaluation for cortisol dynamics including 0800 h and 2000 h plasma cortisol on day 1, cortisol response to insulin induced hypoglycaemia (IIH) on day 2, and 1 mg overnight dexamethasone suppression test (ONDST) on day 4. Serum aldosterone was also measured at 0800 h in fasting state on salt ad libitum for three days. These parameters were repeated 3 months after curative parathyroidectomy. Results: Basal plasma cortisol level at 0800 h and 2000 h were within upper normal range and loss of circadian rhythm in cortisol secretion was observed in half and forty per cent of patients had nonsuppressibility with ONDST. The defined peak cortisol response to insulin induced hypoglycaemia (>550 nmol/l) was achieved in all and nearly one third of patients had exaggerated response (>2000 nmol/l). After curative parathyroidectomy, the abnormalities in circadian rhythm and non-suppressibility with ONDST continued to prevail in 40 per cent of patients. The peak cortisol response to IIH showed a decrement but remained higher than normal. No correlation was observed between circulating parathyroid hormone and calcium with cortisol levels. Serum aldosterone was in upper normal range pre - and postoperatively, though it decreased postoperatively, but it could not attain a statistical significance (p = 0.5). Interpretation & conclusion: Abnormalities in hypothalamo-pituitary-adrenocortical axis in primary hyperparathyroidism do occur, however these are inconsistent and do not recover in majority of patients even after 3 months of curative parathyroidectomy.

Mecanismos de ação dos corticosteróides na polipose rinossinusal: [revisão] / Mechanism of action of glucocorticoids in nasal polyposis: [review]

Os glicocorticóides (GC) são drogas de escolha no tratamento clínico da polipose nasossinusal conforme recomendação da literatura. Entretanto, seus mecanismos de ação nas regressões dos sintomas clínicos e dos pólipos não são totalmente compreendidos. Sabe-se que a administração tópica e ou sistêmica dos glicocorticóides leva a variações na expressão de citocinas, quimiocinas e linfocinas, além das alterações celulares. Assim, os GC suprimem a expressão de citocinas pró-inflamatórias, de quimiocinas, de moléculas de adesão, além de estimular a transcrição de citocinas antiinflamatórias. Citocinas pró-fibróticas como a IL-11, fator básico de crescimento do fibroblasto (b-FGF) e fator de crescimento endotelial vascular (VEGF), relacionados com o crescimento do pólipo, também são suprimidos pela ação do GC. Tal ação depende fundamentalmente da interação com os seus receptores (GR), pois alguns indivíduos apresentam algum grau de resistência celular ao seu efeito, que parece estar relacionada com a presença da isoforma b do GR. Genes envolvidos nas fases de produção de imunoglobulinas, apresentação e processamento do antígeno também sofrem ação dos GC de forma variada. OBJETIVOS: Fazer uma revisão da literatura sobre os mecanismos de ação do GC na PNS. CONCLUSÃO: A compreensão desses mecanismos implicará no desenvolvimento de drogas mais eficazes na sua terapêutica.

Glucocorticoids (GC) are the drugs of choice for the clinical treatment of nasal polyposis, according to the medical literature. Its mechanism of action in the regression of clinical symptoms and polyps, however, is not fully understood. The topical and/or systemic use of glucocorticoids lead to variable expression of cytokines, chemokines and lymphokines, as well as changes in cells. It is known that GC suppresses the expression of pro-inflammatory cytokines, chemokines and adhesion molecules such as ICAM-1 and E-selectin; GC also stimulate the transcription of anti-inflammatory cytokines such as TGF-b. GC suppress pro-fibrotic cytokines related to polyp growth, such as IL-11, the basic fibroblast growth factor (b-FGF), and the vascular endotelial growth factor (VEGF). The action of GC depends fundamentally on their interaction with receptors (GR); certain subjects have a degree of resistance to its effect, which appears to be related with the presence of a b isoform of GR. GC also act variably on the genes involved in immunoglobulin production, presentation, and antigen processing. AIM: We present a review of the literature on the mechanisms of GC action in nasal polyosis. CONCLUSION: Understanding the mechanism of action of GC in nasal polyposis will aid in the development of new, more efficient, drugs.

Adipose tissue expression of 11beta-Hydroxysteroid dehydrogenase type 1 in cushing's syndrome and in obesity

Glucocorticoids have a major role in determining adipose tissue metabolism and distribution. 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) is a NADPH-dependent enzyme highly expressed in the liver and adipose tissue. In most intact cells and tissues it functions as a reductase (to convert inactive cortisone to active cortisol). It has been hypothesized that tissue-specific deregulation of cortisol metabolism may be involved in the complex pathophysiology of the metabolic syndrome (MS) and obesity. Transgenic mice overexpressing 11betaHSD1 in adipose tissue develop obesity with all features of the MS, whereas 11betaHSD1-knockout mice are protected from both. The bulk of evidences points to an overexpression and increased activity of 11betaHSD1 also in human adipose tissue. However, 11betaHSD1 seems to adjust local cortisol concentrations independently of its plasma levels. In Cushing's syndrome, 11betaHSD1 is downregulated and may not be responsible for the abdominal fat depots; it also undergoes downregulation in response to weight loss in human obesity. The nonselective 11betaHSD1 inhibitor carbenoxolone improves insulin sensitivity in humans, and selective inhibitors enhance insulin action in diabetic mice liver, thereby lowering blood glucose. Thus, 11betaHSD1 is now emerging as a modulator of energy partitioning and a promising pharmacological target to treat the MS and diabetes.

Os glicocorticóides (GC) têm papel importante na determinação do metabolismo e da distribuição do tecido adiposo. A 11beta-hidroxisteróide desidrogenase tipo 1 (11betaHSD1) é uma enzima dependente de NADPH, altamente expressa nos tecidos hepático e adiposo. Em muitas células e tecidos intactos, ela funciona como redutase (convertendo cortisona em cortisol). Postula-se que uma desregulação tecido-específica do cortisol estaria envolvida na complexa fisiopatologia da síndrome metabólica (SM) e obesidade. Ratos que super-expressam 11betaHSD1 no tecido adiposo desenvolvem obesidade e todas as características da SM, enquanto ratos knockout para 11betaHSD1 são protegidos. Evidências apontam para uma super-expressão e aumento da atividade 11betaHSD1 também no tecido adiposo humano. Entretanto, a 11betaHSD1 parece ajustar a concentração local de cortisol independente da sua concentração sérica. Na síndrome de Cushing, a expressão da 11betaHSD1 é regulada para baixo, não devendo ser a causa dos depósitos de gordura visceral; em obesos, há também regulação para baixo em resposta à perda de peso. A carbenoxolona, um inibidor não seletivo da 11betaHSD1, melhora a sensibilidade insulínica em humanos e inibidores seletivos aumentam a sensibilidade insulínica hepática e melhoram o controle glicêmico em ratos diabéticos. Assim, a 11betaHSD1 está emergindo como um modulador da compartimentalização de energia e um alvo farmacológico promissor para o tratamento da SM e do diabetes.

Depressão e estresse: existe um endofenótipo? / Depression and stress: is there an endophenotype?

OBJETIVO: Revisar os achados recentes sobre a relação entre estresse, eixo hipotálamo-pituitária-adrenal e depressão, na tentativa de explicar um endofenótipo de vulnerabilidade para o desenvolvimento da depressão. MÉTODO: Revisão não sistemática da literatura baseada na hipótese de endofenótipo. RESULTADOS: A depressão está relacionada à hipercortisolemia em muitos pacientes; porém, nem todos os deprimidos apresentam esta alteração na função hipotálamo-pituitária-adrenal. Os primeiros estudos publicados observaram esta hiperativação do eixo hipotálamo-pituitária-adrenal por meio do teste de supressão da dexametasona. Estes resultados não foram largamente replicados em grande parte devido à falta de acurácia desse teste. A hipercortisolemia ocorre freqüentemente em pacientes com depressão grave, do tipo melancólico, psicóticos ou não. Está relacionada a um polimorfismo específico do gene do transportador da serotonina; a história de abuso ou negligência durante a infância ou perda parental precoce; e ao temperamento que resulta em alterações na resposta ao estresse. CONCLUSÕES: As alterações do eixo hipotálamo-pituitária-adrenal dependem de diversos fatores, como gravidade e tipo de depressão, genótipo, história de trauma na infância, temperamento e, provavelmente, resiliência. Todas essas variáveis se relacionam a um endofenótipo vulnerável ao desenvolvimento de depressão.

OBJECTIVE: To review the new findings about stress, hypothalamic-pituitary-adrenal axis and depression trying to explain a possible endophenotype prone to depression. METHOD: Nonsystematic review of the literature based on the endophenotype hypothesis. RESULTS: Depression is linked to hypercortisolemia in many patients, but not all patients present these hypothalamic-pituitary-adrenal axis dysfunction. The dexamethasone suppression test is not the most accurate test to measure the hypothalamic-pituitary-adrenal axis function, and its use in the first studies published probably jeopardized the results. Hypercortisolemia frequently occurs in patients with severe depression, melancholic, either psychotic or nonpsychotic type; it is linked to the presence of a polymorphism in the promoter of the serotonin transporter gene, with a history of childhood abuse or neglect, or other significant stressful experiences like the loss of a parent during childhood and temperament leading to alterations in the response to stress. CONCLUSIONS: The alterations of the hypothalamic-pituitary-adrenal axis depend on many factors like severity and type of depression, genotype, history of exposure to stress, temperament, and probably resilience. All these factors together result in an endophenotype thought to be prone to depression.

Repercussões imunológicas dos distúrbios do sono: o eixo hipotálamo-pituitária-adrenal como fator modulador / Immune outcomes of sleep disorders: the hypothalamic-pituitary-adrenal axis as a modulatory factor

OBJETIVO: Revisar a literatura a respeito da interação entre sono e sistema imunológico. MÉTODO: Busca no Web of Science e no PubMed com os descritores: sono, privação de sono, estresse, eixo hipotálamo-pituitária-adrenal, sistema imunológico e doenças auto-imunes. RESULTADOS: Foram encontrados 588 artigos no Web of Science. As 61 referências mais significativas e mais relacionadas aos objetivos do estudo foram utilizadas. Foram incluídos artigos originais e de revisão. CONCLUSÃO: A privação de sono e o sistema imunológico exercem e sofrem influências mútuas. A privação de sono é considerada um estressor, uma vez que induz a elevação do cortisol em seres humanos - ou da corticosterona em roedores. Os glicocorticóides, por sua vez, exercem um efeito imunossupressor. Por essas razões, foi proposto que o aumento da ativação do eixo hipotálamo-pituitária-adrenal seja um importante mediador das alterações imunológicas observadas em pacientes com insônia ou privados de sono.

OBJECTIVE: To review the literature on the interaction between sleep and the immune system. METHOD: A search on Web of Science and Pubmed database including the keywords sleep, sleep deprivation, stress, hypothalamic-pituitary-adrenal axis, immune system, and autoimmune diseases. RESULTS: On Web of Science, 588 publications were retrieved; 61 references, more significant and closer to our objective, were used, including original articles and review papers. CONCLUSION: Sleep deprivation and immune system exert a bidirectional influence on each other. Since sleep deprivation is considered a stressor, inasmuch as it induces elevation of cortisol or corticosterone levels in humans and rodents, respectively, and given the well-known immunosuppressive effect of glucocorticoids, we propose that increased activation of the hypothalamic-pituitary-adrenal axis is a major mediator of the immune alterations observed in patients with insomnia or in sleep deprived subjects.

Aspectos moleculares da sensibilidade aos glicocorticóides / Molecular aspects of glucocorticoid sensitivity / Molecular aspects of glucocorticoid sensitivity

Os glicocorticóides exercem um papel importante na regulação fisiológica e na adaptação a situações de stress, sendo a maioria dos efeitos destes hormônios mediada pela interação com os receptores glicocorticóides. A sensibilidade ao glicocorticóide depende da densidade celular de receptores expressos, bem como da eficiência da transdução do sinal mediada pelo complexo hormônio-receptor. Os estados de resistência ou de hipersensibilidade ao glicocorticóide, observados, respectivamente, nas doenças inflamatórias auto-imunes e na síndrome metabólica, podem representar a variabilidade dos fatores que influenciam a cascata de sinalização do glicocorticóide. O reconhecimento destes fatores contribui para uma melhor compreensão tanto do fenótipo clínico e da evolução destas doenças quanto da resposta terapêutica com glicocorticóide. A compreensão destes mecanismos fisiopatológicos também pode contribuir para a escolha de intervenções terapêuticas. Neste artigo de revisão, descrevemos os múltiplos fatores envolvidos nesta cascata de sinalização, os quais são capazes de influenciar a sensibilidade ao glicocorticóide.

Glucocorticoids play an essential role in maintaining basal and stress-related homeostasis. Most known effects of glucocorticoids are mediated by the intracellular glucocorticoid receptors. The glucocorticoid sensitivity seems to depend on the amount of receptors expressed and the efficiency of glucocorticoid receptor-mediated signal transduction. Glucocorticoid resistance or hypersensitivity, seen in autoimmune-inflammatory diseases and in metabolic syndrome respectively, can represent the variability of several steps that influence the signaling cascade of glucocorticoid action. The recognition of these steps could provide the understanding of the clinical phenotype and course of such diseases as well as their responsiveness to glucocorticoid therapy. The comprehension of these pathophysiological mechanisms can also improve the possible therapeutic interventions. In this review, we have summarized the multiple factors that have been shown to be involved in this signaling cascade and, thus, to influence glucocorticoid sensitivity.

A treatise on hazards of endocrine disruptors and tool to evaluate them.

Hormones mediate a major part of our essential physiological functions. Both endogenous and exogenous compounds and their metabolites are known to act through hormone receptors leading to regulation of endocrine function. The endogenous ligands that control reproductive functions are generally steroids such as 17beta-estradiol, androgens, progesterone, pregnenolone and glucocorticoids. However, exogenous compounds that are structurally and functionally similar gain entry into animals including humans through the diet or by occupational exposures, causing endocrine disruption. In the recent decade, there is a lot of apprehension about the so-called "endocrine disruptors" which are wide spread in the environment, mainly due to unrestricted human activity. These compounds of anthropogenic or natural origin mimic the action of sex hormones and can interfere with the endocrine system. It has been hypothesized that environmental exposure to synthetic estrogenic chemicals and related endocrine active compounds may be responsible for malformations in the male reproductive tract, crytorchidism, hypospadias, decrease in sperm counts, decreased male reproductive capacity and even testicular cancers. The increasing concern in both public and scientific communities about these abnormalities have prompted the initiation of epidemiological studies to not only identify, but to also analyze the short and long term effects of endocrine disruptors. As a result, a number of assays have been developed and are undergoing validation aimed at high throughput screening of chemical agents that disrupt endocrine activity. This review consolidates the findings of epidemiological studies, particularly in relation to male reproductive disorders and brings to light the various types of in vitro and in vivo models that are available for tiered testing of suspected compounds.

Mast cell changes in experimental diabetes: focus on attenuation of allergic events

The prevalence of atopic diseases and diabetes is increasing worldwide though the concurrence of these pathologies in individual patients is found less frequent than it would be predicted. Moreover, co-existence of diabetes and allergy is generally marked by attenuation of their respective symptoms, and effective treatment of one disease exacerbates the other. This review gives an update of the state-of-the-art concerning the intercurrence of allergy and diabetes, particularly focusing on the consequences to the allergen-evoked vascular and cellular changes. It is proposed that the reduction in mast cell numbers and reactivity may be a pivotal mechanism behind the mutual exclusion phenomenon.

Effects of Methylprednisolone on the Neural Conduction of the Motor Evoked Potentials in Spinal Cord Injured Rats

Methylprednisolone (MP), a glucocorticoid steroid, has an anti-inflammatory action and seems to inhibit the formation of oxygen free radicals produced during lipid peroxidation in a spinal cord injury (SCI). However, the effects of MP on the functional recovery after a SCI is controversial. The present study was conducted to determine the effects of MP on the recovery of neural conduction following a SCI. A SCI was produced using the NYU spinal cord impactor. A behavioral test was conducted to measure neurological disorders, and motor evoked potentials (MEPs) were recorded. According to the behavioral test, using BBB locomotor scaling, MP-treated animals showed improved functional recoveries when compared to salinetreated animals. MEP latencies in the MP-treated group were shortened when compared to those in the control group. Peak amplitudes of MEPs were larger in the MP-treated group than those in the control group. The thresholds of MEPs tended to be lower in the MP-treated group than those in the control group. These results suggest that MP may improve functional recovery after a SCI.