RESUMO
Brain-Derived Neurotrophic Factor (BDNF) has been linked to various conditions of the cardiovascular and nervous systems. Scarce data exist about the concentrations of BDNF in children and adolescents in relation with obesity and metabolic syndrome (MetS). The aim of this study was to examine the serum BDNF concentrations in adolescents with metabolic syndrome and according to their body mass index (BMI) status. This was a case-control study, assessing BDNF concentrations between adolescents with MetS (with obesity vs. normal-BMI), in relation to sex, anthropometric, metabolic and endocrine parameters. Participants included male and female adolescents, whose anthropometric and metabolic panel, as well as serum BDNF concentrations were measured. A total of 59 adolescents (obesity: 29; normal-BMI: 30) were included in the study. Increased serum BDNF concentrations were observed in MetS adolescents with obesity when compared with normal-BMI adolescents (p < 0.001). Males exhibited higher concentrations of BDNF than females (p = 0.045). The sample was further divided into four categories by sex and BMI status, with normal-BMI females exhibiting significantly lower BDNF concentrations than females and males with obesity(p = 0.005). In the entire study sample, serum BDNF concentrations correlated positively with BMI z-scores, however, this statistical significance was preserved only in the females of the sample. No statistical difference was observed between males of different BMI z-scores categories. Conclusion: Obesity appeared as a major factor for increased serum BDNF concentrations in adolescents with MetS (vs. normal-BMI), with a higher impact on BDNF concentrations in females than males. What is Known: ⢠The brain-derived neurotrophic factor (BDNF) is involved in metabolic syndrome in adults but data in adolescents are scarce. What is New: ⢠Obesity (vs. normal BMI) was a major factor for increased serum BDNF in adolescents with metabolic syndrome. ⢠Obesity had a higher impact on BDNF concentrations in females than males with metabolic syndrome.
Assuntos
Síndrome Metabólica , Obesidade Infantil , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Índice de Massa Corporal , Fator Neurotrófico Derivado do Encéfalo , Estudos de Casos e Controles , Obesidade Infantil/complicaçõesRESUMO
OBJECTIVE: To present the initial assessment of psychosocial adaptation among Greek parents whose children were newly diagnosed with cancer amidst the turmoil of an ongoing financial crisis. STUDY DESIGN: This prospective observational study used a quantitative approach. PARTICIPANTS: Sixty-one parents of children with cancer treated at a large urban tertiary-care children's hospital were prospectively recruited to participate in our study during the first week of their child's diagnosis (2013-2016). METHODS: The parents were asked to complete the psychosocial assessment tool (PAT 2.0), Zung Depression Scale, State-Trait Anxiety Inventory, Hospital Anxiety and Depression Scale, and World Health Organization Quality of Life-Bref Instrument; Moreover, three female healthcare providers (the physician oncologist, the head nurse and a senior nurse) completed the relevant PAT 2.0 -Staff Perceptions questionnaire the results of which were then compared to those of the child's parent. FINDINGS: The majority of parents had PAT 2.0 scores indicative of increased psychosocial risk :54% were stratified into the "Targeted" (moderate risk) and 15% into the "Clinical" (highest risk) categories, whereas healthcare providers underestimated psychosocial risk in 57%-59% of the cases. The subscales that most contributed to the increased scores were Parental Stress Reaction, Family Structure and Resources, and Family Social Support. The PAT 2.0 had statistically significant correlations with most of the anxiety and depression scales, with Zung having the strongest correlation (r-value: +0.5, p-value <0.01). Our cohort presented more anxiety and depression compared to the general Greek population (14% for depression versus 2,9% for the general population and 46% for anxiety compared to 4,1%) in the years of financial recession in Greece. CONCLUSIONS: The parents of children newly diagnosed with cancer in Greece are at increased risk for developing anxiety and depression in the years of financial recession in Greece compared to general population. IMPLICATIONS FOR PSYCHOSOCIAL PROVIDERS: Parental stress reaction to diagnosis as well as lack of family resources and social support may contribute to this difference. Screening for psychosocial risk factors is essential for the early identification of these families and for the optimal utilization of the limited available resources in times of economic hardship.
RESUMO
Female infertility and reproduction is an ongoing and rising healthcare issue, resulting in delaying the decision to start a family. Therefore, in this review, we examine potential novel metabolic mechanisms involved in ovarian aging according to recent data and how these mechanisms may be addressed through new potential medical treatments. We examine novel medical treatments currently available based mostly on experimental stem cell procedures as well as caloric restriction (CR), hyperbaric oxygen treatment and mitochondrial transfer. Understanding the connection between metabolic and reproductive pathways has the potential to offer a significant scientific breakthrough in preventing ovarian aging and prolonging female fertility. Overall, the field of ovarian aging is an emerging field that may expand the female fertility window and perhaps even reduce the need for artificial reproductive techniques.
Assuntos
Envelhecimento , Infertilidade Feminina , Feminino , Humanos , Ovário/metabolismo , Reprodução , Infertilidade Feminina/metabolismo , Técnicas Reprodutivas , Oócitos/metabolismoRESUMO
In this review, we analyzed existing literature regarding the use of Gonadotropin-releasing Hormone (GnRH) analogues (agonists, antagonists) as a co-treatment to chemotherapy and radiotherapy. There is a growing interest in their application as a prophylaxis to gonadotoxicity caused by chemotherapy and/or radiotherapy due to their ovarian suppressive effects, making them a potential option to treat infertility caused by such chemotherapy and/or radiotherapy. They could be used in conjunction with other fertility preservation options to synergistically maximize their effects. GnRH analogues may be a valuable prophylactic agent against chemotherapeutic infertility by inhibiting rapid cellular turnover on growing follicles that contain types of cells unintentionally targeted during anti-cancer treatments. These could create a prepubertal-like effect in adult women, limiting the gonadotoxicity to the lower levels that young girls have. The use of GnRH agonists was found to be effective in hematological and breast cancer treatment whereas for ovarian endometrial and cervical cancers the evidence is still limited. Studies on GnRH antagonists, as well as the combination of both agonists and antagonists, were limited. GnRH antagonists have a similar protective effect to that of agonists as they preserve or at least alleviate the follicle degradation during chemo-radiation treatment. Their use may be preferred in cases where treatment is imminent (as their effects are almost immediate) and whenever the GnRH agonist-induced flare-up effect may be contra-indicated. The combination treatment of agonists and antagonists has primarily been studied in animal models so far, especially rats. Factors that may play a role in determining their efficacy as a chemoprotective agent that limits gonadal damage, include the type and stage of cancer, the use of alkylating agents, age of patient and prior ovarian reserve. The data for the use of GnRH antagonist alone or in combination with GnRH agonist is still very limited. Moreover, studies evaluating the impact of this treatment on the ovarian reserve as measured by Anti-Müllerian Hormone (AMH) levels are still sparse. Further studies with strict criteria regarding ovarian reserve and fertility outcomes are needed to confirm or reject their role as a gonadal protecting agent during chemo-radiation treatments.
Assuntos
Fertilidade/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/farmacologia , Neoplasias/tratamento farmacológico , Reprodução/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Feminino , Preservação da Fertilidade/métodos , Humanos , Ovário/efeitos dos fármacosRESUMO
Glucocorticoids are ubiquitous, pleotropic steroid hormones secreted from the cortices of the adrenal glands in a circadian fashion under the strong influence of the central Clock center located in the suprachiasmatic nuclei (SCN) of the hypothalamus. In previous work, we reported that the circadian transcription factor CLOCK and its heterodimer partner BMAL1 suppress the transcriptional activity of the glucocorticoid receptor (GR) by acetylating a lysine cluster located in its hinge region between the DNA- and ligand-binding domains. This regulation of GR transcriptional activity by CLOCK/BMAL1 functions as a counter-regulatory loop against the diurnally fluctuating circulating glucocorticoids. Here, we have performed further analyses of our data using bioinformatics and computational methods. Gene expression data were analyzed using unsupervised machine learning methods, such as hierarchical clustering, k-means, Naïve Bayes classification, and polynomial regression analyses. We determined expression patterns of Clock-related genes, unraveled the dynamics of spatial data, and defined the temporal function of Clock-mediated GR-regulated genes. Gene expressions manifested nonlinear dynamics, possibly because we obtained dynamic results from stationary measurements. The mechanics of the circadian rhythms are still obscure, and more studies are required to understand how such rhythms influence mammalian physiology.
Assuntos
Relógios Circadianos , Receptores de Glucocorticoides , Animais , Teorema de Bayes , Proteínas CLOCK/genética , Relógios Circadianos/genética , Biologia Computacional , Expressão Gênica , Receptores de Glucocorticoides/genéticaRESUMO
Glucocorticoids are the final products of the neuroendocrine hypothalamic-pituitary-adrenal axis, and play an important role in the stress response to re-establish homeostasis when it is threatened, or perceived as threatened. These steroid hormones have pleiotropic actions through binding to their cognate receptor, the human glucocorticoid receptor, which functions as a ligand-bound transcription factor inducing or repressing the expression of a large number of target genes. To achieve homeostasis, glucocorticoid signaling should have an optimal effect on all tissues. Indeed, any inappropriate glucocorticoid effect in terms of quantity or quality has been associated with pathologic conditions, which are characterized by short-term or long-lasting detrimental effects. Two such conditions, the primary generalized glucocorticoid resistance and hypersensitivity syndromes, are discussed in this review article. Undoubtedly, the tremendous progress of structural, molecular, and cellular biology, in association with the continued progress of biotechnology, has led to a better and more in-depth understanding of these rare endocrinologic conditions, as well as more effective therapeutic management.
Assuntos
Síndrome de Hipersensibilidade a Medicamentos/patologia , Resistência a Medicamentos/genética , Glucocorticoides/farmacologia , Erros Inatos do Metabolismo/patologia , Receptores de Glucocorticoides/deficiência , Receptores de Glucocorticoides/genética , Animais , Síndrome de Hipersensibilidade a Medicamentos/etiologia , Síndrome de Hipersensibilidade a Medicamentos/metabolismo , Humanos , Erros Inatos do Metabolismo/genéticaRESUMO
Stress is defined as a state of threatened or perceived as threatened homeostasis. The well-tuned coordination of the stress response system is necessary for an organism to respond to external or internal stressors and re-establish homeostasis. Glucocorticoid hormones are the main effectors of stress response and aberrant glucocorticoid signaling has been associated with an increased risk for psychiatric and mood disorders, including schizophrenia, post-traumatic stress disorder and depression. Emerging evidence suggests that life-stress experiences can alter the epigenetic landscape and impact the function of genes involved in the regulation of stress response. More importantly, epigenetic changes induced by stressors persist over time, leading to increased susceptibility for a number of stress-related disorders. In this review, we discuss the role of glucocorticoids in the regulation of stress response, the mechanism through which stressful experiences can become biologically embedded through epigenetic alterations, and we underline potential associations between epigenetic changes and the development of stress-related disorders.
Assuntos
Glucocorticoides/fisiologia , Receptores de Glucocorticoides/metabolismo , Transtornos de Estresse Pós-Traumáticos/metabolismo , Estresse Psicológico/metabolismo , Epigênese Genética , Humanos , Transdução de SinaisRESUMO
BACKGROUND: Obesity in adulthood is associated with decreased leucocyte telomere length (LTL), which is associated with cardiovascular disease and diabetes mellitus type 2. The aim of our study was to investigate whether increased body mass index (BMI) is associated with decreased LTL in children and adolescents, and to identify other risk factors of shorter LTL in this population. MATERIALS AND METHODS: A cross-sectional study was conducted among 919 Greek children aged 9-13 years (The Healthy Growth Study). Participants were classified as obese (n = 124), overweight (n = 276) or of normal BMI (n = 519). LTL was determined by monochrome multiplex quantitative real-time polymerase chain reaction. Univariate and multivariable linear regression analyses were applied to determine the predictive factors of LTL. RESULTS: Both overweight and obese children had significantly shorter LTL than their normal-BMI counterparts. Following adjustment for age, sex, total daily energy intake and average weekly physical activity (average total steps per day), increasing weight category was inversely associated with LTL in children and adolescents (ß: -0.110 ± 0.035; P = .002). CONCLUSION: Overweight and obesity in childhood and adolescence are associated with shorter LTL, even following adjustment for potential confounding effects. Therefore, the increased BMI in childhood and adolescence may be associated with accelerated biological ageing and may have an adverse impact on future health in adulthood.
Assuntos
Envelhecimento/metabolismo , Leucócitos/metabolismo , Obesidade Infantil/metabolismo , Telômero/metabolismo , Adolescente , Índice de Massa Corporal , Estudos de Casos e Controles , Criança , Feminino , Grécia , Humanos , Modelos Lineares , Masculino , Reação em Cadeia da Polimerase Multiplex , Análise Multivariada , Reação em Cadeia da Polimerase em Tempo RealRESUMO
BACKGROUND: Childhood obesity represents a major health problem of our century. The benefits of natural products, such as honey, in the management of obesity have gained renewed interest. In this study, we investigated the effect of honey on glucose and insulin concentrations in obese prepubertal girls. MATERIALS AND METHODS: Thirty healthy obese girls aged 10.55 (±SEM:0.34) years with a mean body mass index (BMI) above the 97th centile for age (28.58 ± 1.40 kg/m2 , BMI z-score 2.96) underwent a standard oral glucose tolerance test (OGTT) followed by an oral honey tolerance test (OHTT) 2 weeks later. Both solutions contained 75 g of glucose. Subsequently, subjects were randomized to receive either 15 g of honey or 15 g of marmalade daily, while both groups complied with dietetic instructions. Six months later all subjects were re-evaluated with an OGTT and an OHTT. RESULTS: At the end of the study, all subjects demonstrated a significant reduction in BMI (27.57 ± 1.40, z-score: 2.54 vs 28.58 ± 1.40 kg/m2 , z-score: 2.96, P < 0.001), however, there were no significant differences in BMI and all parameters tested between the group that received honey and the control group. The areas under the concentration-time curve for glucose and insulin for the entire population were significantly lower following ingestion of honey than glucose solution (P < 0.001) both at the beginning and at the end of study. CONCLUSIONS: These findings indicate that honey does not have an effect on stimulated plasma glucose and serum insulin concentrations compared with the standard glucose solution in obese prepubertal girls.
Assuntos
Glicemia/metabolismo , Mel , Insulina/metabolismo , Obesidade Infantil/sangue , Biomarcadores/metabolismo , Índice de Massa Corporal , Criança , Feminino , Seguimentos , Glucose/administração & dosagem , Teste de Tolerância a Glucose , Humanos , Edulcorantes/administração & dosagemRESUMO
BACKGROUND: Synthetic glucocorticoids are widely used in the treatment of several inflammatory, autoimmune and lymphoproliferative disorders. However, considerable variation in response to therapeutic doses of glucocorticoids has been documented among individuals. The aim of our study was to identify novel glucocorticoid sensitivity-determining genes using genome-wide expression profiling in healthy subjects. METHODS: One hundred one healthy subjects [mean age ± standard error of the mean (SEM); 26.52 ± 0.50 years] were given 0.25 mg dexamethasone at midnight, and serum cortisol concentrations were determined at 08:00 hours the following morning. Subjects were stratified into the 10% most glucocorticoid-sensitive and 10% most glucocorticoid-resistant according to the serum cortisol concentrations. Genomic DNA, RNA and plasma samples were obtained in the 22 subjects one month later. RESULTS: Transcriptomic analysis showed variability between glucocorticoid-resistant and glucocorticoid-sensitive subjects. One hundred thirty-three genes were upregulated and 49 downregulated in the glucocorticoid-resistant compared to the glucocorticoid-sensitive group. Further analysis revealed differences between 3 glucocorticoid-resistant and 3 glucocorticoid-sensitive subjects. The majority of the 1058 upregulated genes and 1139 downregulated genes were found to participate in telomere maintenance, systemic lupus erythematosus and Alzheimer's disease. Interestingly, Synuclein A, a key molecule in Parkinson's disease, was upregulated in the subgroup of glucocorticoid-sensitive subjects. CONCLUSIONS: We have identified differences in tissue sensitivity to glucocorticoids among healthy subjects at the transcriptomic level. These differences are associated with differential expression of genes related to autoimmune and neurological disorders.
Assuntos
Dexametasona/farmacologia , Glucocorticoides/farmacologia , Transcriptoma/efeitos dos fármacos , Adulto , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Regulação para Baixo/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica , Humanos , Hidrocortisona/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/genética , Masculino , Receptores de Glucocorticoides/genética , Homeostase do Telômero/efeitos dos fármacos , Homeostase do Telômero/genética , Regulação para Cima/efeitos dos fármacos , alfa-Sinucleína/sangueRESUMO
BACKGROUND: Obesity in childhood and adolescence represents a major health problem in our century. In Greece, more than 30%-35% of children and adolescents are either overweight or obese. MATERIALS AND METHODS: Using information and communication technologies, we developed a "National Registry for the Prevention and Management of Overweight and Obesity in Childhood and Adolescence" for guidance and training of Pediatricians and General Practitioners. The application supports interoperability with other national infrastructures and multi-layered security spanning preventive, detective and administrative controls. The Patient Summary Dataset includes information on medical history, family history, medications, immunizations, clinical examination and laboratory findings and appointment booking service. RESULTS: The application was launched in September 2015 and is accessible by: http://app.childhood-obesity.gr/. Based on the data that the doctor registers, the system calculates a personalized therapeutic algorithm that provides information on diet, physical exercise and sleep, as well as guidance on laboratory investigations and referral to specialized centres. A pilot study performed in 1270 children and adolescents indicated that using this system resulted in a reduction in obesity rates by 30% and overweight rates by 35% within 1 year. CONCLUSIONS: This National e-Health System appears to be effective in the management of overweight and obesity in childhood and adolescence.
Assuntos
Obesidade Infantil/terapia , Adolescente , Idade de Início , Índice de Massa Corporal , Criança , Feminino , Grécia/epidemiologia , Humanos , Masculino , Obesidade Infantil/epidemiologia , Projetos Piloto , Sistema de Registros , Distribuição por SexoRESUMO
BACKGROUND: The aim of this meta-analysis was to examine differences and predictors of serum 25-hydroxyvitamin D concentrations in women with polycystic ovary syndrome (PCOS) compared with non-PCOS controls matched for body mass index. MATERIALS AND METHODS: Three databases were searched (2003-2015) to retrieve studies that evaluated serum 25-hydroxyvitamin D in PCOS women and controls. Meta-regression analysis was performed with anthropometric and metabolic/endocrine parameters as covariates. RESULTS: Fourteen studies that included 2262 women (1150 PCOS patients/1162 controls) were eligible. Serum 25-hydroxyvitamin D, follicle-stimulating hormone and sex hormone-binding globulin were significantly lower in patients with PCOS than controls. Homoeostatic model assessment-insulin resistance index, serum insulin, total cholesterol, triglycerides, low-density lipoprotein cholesterol, luteinising hormone and testosterone were significantly higher in patients with PCOS compared to controls. Meta-regression analysis demonstrated significant effects of waist-to-hip ratio and glucose in PCOS women (ß = -1·60, 95% CI: -2·30 to -0·90, P = 0·003; ß = 0·20, 95% CI: 0·80-0·32, P = 0·004, respectively) and controls (ß = -2·36, 95% CI: -3·38 to -1·33, P = 0·003; ß = 0·11, 95% CI: 0·00-0·21, P = 0·05, respectively) and of total calcium and luteinising hormone in PCOS cases (ß = 2·43, 95% CI: 1·67-3·19, P = 0·005; ß = -0·37, 95% CI: -0·68 to -0·06, P = 0·03, respectively). CONCLUSIONS: Serum 25-hydroxyvitamin D may be predicted positively by serum calcium and negatively by luteinising hormone in women with PCOS, and negatively by waist-to-hip ratio and positively by fasting glucose in both PCOS and non-PCOS women, independently of the presence of obesity.
Assuntos
Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/diagnóstico , Vitamina D/análogos & derivados , Relação Cintura-Quadril , Biomarcadores/sangue , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Humanos , Incidência , Síndrome do Ovário Policístico/epidemiologia , Valor Preditivo dos Testes , Prognóstico , Valores de Referência , Medição de Risco , Vitamina D/sangueRESUMO
BACKGROUND: Stress is defined as a state of threatened or perceived as threatened homeostasis. A broad spectrum of extrinsic or intrinsic, real or perceived stressful stimuli, called 'stressors', activates a highly conserved system, the 'stress system', which adjusts homeostasis through central and peripheral neuroendocrine responses. Inadequate, excessive or prolonged adaptive responses to stress may underlie the pathogenesis of several disease states prevalent in modern societies. The development and severity of these conditions primarily depend on the genetic vulnerability of the individual, the exposure to adverse environmental factors and the timing of the stressful event(s), given that prenatal life, infancy, childhood and adolescence are critical periods characterized by increased vulnerability to stressors. MATERIALS AND METHODS: We conducted a systematic review of original articles and reviews published in MEDLINE from 1975 through June 2016. The search terms were 'childhood stress', 'pediatric stress', 'stress and disorders' and 'stress management'. RESULTS: In this review, we discuss the historical and neuroendocrine aspects of stress, and we present representative examples of paediatric stress system disorders, such as early-life adversity, obesity and bullying. We also discuss the adverse impact of a socio-economic crisis on childhood health. The tremendous progress of epigenetics has enabled us to have a deeper understanding of the molecular mechanisms underlying paediatric stress-related disorders. CONCLUSIONS: The need for early successful stress management techniques to decrease the incidence of paediatric stress-related diseases, as well as to prevent the development of several pathologic conditions in adolescence and adulthood, is imperative.
Assuntos
Neuroendocrinologia , Sistemas Neurossecretores/fisiopatologia , Obesidade/fisiopatologia , Estresse Fisiológico , Estresse Psicológico/fisiopatologia , Criança , HumanosRESUMO
BACKGROUND: Germline mutations of the KCNJ5 gene encoding Kir3·4, a member of the inwardly rectifying K+ channel, have been identified in 'normal' adrenal glands, patients with familial hyperaldosteronism (FH) type III, aldosterone-producing adenomas (APAs) and sporadic cases of primary aldosteronism (PA). OBJECTIVE: To present two novel KCNJ5 gene mutations in hypertensive patients without PA, but with Adrenocorticotropic hormone (ACTH)-dependent aldosterone hypersecretion. DESIGN AND PATIENTS: Two hypertensive patients without PA, who exhibited enhanced ACTH-dependent response of aldosterone secretion, underwent genetic testing for the presence of the CYP11B1/CYP11B2 chimeric gene and KCNJ5 gene mutations. Genomic DNA was isolated from peripheral white blood cells, and the exons of the entire coding regions of the above genes were amplified and sequenced. Electrophysiological studies were performed to determine the effect of identified mutation(s) on the membrane reversal potentials. Structural biology studies were also carried out. RESULTS: Two novel germline heterozygous KCNJ5 mutations, p.V259M and p.Y348N, were detected in the two subjects. Electrophysiological studies showed that the Y348N mutation resulted in significantly less negative reversal potentials, suggesting loss of ion selectivity, while the V259M mutation did not affect the Kir3.4 current. In the mutated structural biology model, the N348 mutant resulted in significant loss of the ability for hydrogen bonding, while the M259 mutant was capable of establishing weaker interactions. The CYP11B1/CYP11B2 chimeric gene was not detected. CONCLUSIONS: These findings expand on the clinical spectrum of phenotypes associated with KCNJ5 mutations and implicate these mutations in the pathogenesis of hypertension associated with increased aldosterone response to ACTH stimulation.
Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Aldosterona/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Mutação em Linhagem Germinativa/fisiologia , Hipertensão/etiologia , Citocromo P-450 CYP11B2/genética , Fenômenos Eletrofisiológicos , Feminino , Estudos de Associação Genética , Humanos , Hiperaldosteronismo , Masculino , Pessoa de Meia-Idade , Esteroide 11-beta-Hidroxilase/genéticaRESUMO
BACKGROUND: Chrousos syndrome is a rare pathologic condition characterized by generalized, partial resistance of target tissues to glucocorticoids and caused by inactivating mutations of the human glucocorticoid receptor (hGR) gene. A novel case of Chrousos syndrome has been reported in a patient with adrenal incidentaloma, who harboured a heterozygous point mutation in the hGR gene, which resulted in threonine (T) to isoleucine (I) substitution at amino acid position 556 in the ligand-binding domain of the receptor. OBJECTIVE: To delineate the molecular mechanisms through which the mutant receptor hGRαT556I causes Chrousos syndrome. DESIGN AND RESULTS: Compared with the wild-type receptor, the mutant receptor hGRαT556I demonstrated 50% reduction in its ability to transactivate glucocorticoid-responsive genes and in the affinity for the ligand, 30% increase in the ability to transrepress the nuclear factor-κB-target genes and a 3,4-fold delay in the cytoplasmic-to-nuclear translocation. The mutant receptor hGRαT556I did not exert a dominant negative effect upon the hGRα-mediated transcriptional activity; it preserved its ability to bind to DNA and interacted with the glucocorticoid receptor-interacting protein 1 coactivator mostly through its activation function-1 domain. Structural biology studies revealed that the T556I mutation caused disruption of the hydrogen bond formed by the T556 with the =O group of P637 backbone, which resulted in a significant relocation of the P637-bearing loop. This conformational alteration affected the local 3D arrangement of the receptor and hence the electrostatic surface of the region. CONCLUSIONS: The hGRαT556I causes Chrousos syndrome by impairing multiple steps of the glucocorticoid signal transduction pathway.
Assuntos
Erros Inatos do Metabolismo/genética , Receptores de Glucocorticoides/deficiência , Animais , Western Blotting , Células COS , Chlorocebus aethiops , Dexametasona/metabolismo , Glucocorticoides/metabolismo , Células HCT116 , Células HeLa , Humanos , Coativador 2 de Receptor Nuclear/metabolismo , Mutação Puntual , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Transdução de SinaisRESUMO
Adrenal insufficiency is the clinical manifestation of deficient production or action of glucocorticoids, with or without deficiency also in mineralocorticoids and adrenal androgens. It is a life-threatening disorder that can result from primary adrenal failure or secondary adrenal disease due to impairment of the hypothalamic-pituitary axis. Prompt diagnosis and management are essential. The clinical manifestations of primary adrenal insufficiency result from deficiency of all adrenocortical hormones, but they can also include signs of other concurrent autoimmune conditions. In secondary or tertiary adrenal insufficiency, the clinical picture results from glucocorticoid deficiency only, but manifestations of the primary pathological disorder can also be present. The diagnostic investigation, although well established, can be challenging, especially in patients with secondary or tertiary adrenal insufficiency. We summarise knowledge at this time on the epidemiology, causal mechanisms, pathophysiology, clinical manifestations, diagnosis, and management of this disorder.
Assuntos
Insuficiência Adrenal , Insuficiência Adrenal/diagnóstico , Insuficiência Adrenal/etiologia , Insuficiência Adrenal/terapia , Feminino , Humanos , Gravidez , Complicações na GravidezRESUMO
BACKGROUND: Hydrocortisone therapy should be individualized in congenital adrenal hyperplasia (CAH) patients to avoid over and under replacement. We have assessed how differences in absorption and half-life of cortisol influence glucocorticoid exposure. PATIENTS AND METHODS: Forty-eight patients (21 M) aged between 6·1 and 20·3 years with CAH due to CYP21A2 deficiency were studied. Each patient underwent a 24-h plasma cortisol profile with the morning dose used to calculate absorption parameters along with an intravenous (IV) hydrocortisone (15 mg/m(2) body surface area) bolus assessment of half-life. Parameters derived were maximum plasma concentration (Cmax ), time of maximum plasma concentration (tmax ), time to attaining plasma cortisol concentration <100 nmol/l and half-life of cortisol. RESULTS: Mean half-life was 76·5 ± 5·2 (range 40-225·3) min, Cmax 780·7 ± 61·6 nmol/l and tmax 66·7 (range 20-118) min. Time taken to a plasma cortisol concentration less than 100 nmol/l was 289 (range 140-540) min. Those with a fast half-life and slow tmax took longest to reach a plasma cortisol concentration less than 100 nmol/l (380 ± 34·6 min), compared to those with a slow half-life and fast tmax (298 ± 34·8 min) and those with a fast half-life and fast tmax (249·5 ± 14·4 min) (One-way anovaF = 4·52; P = 0·009). CONCLUSIONS: Both rate of absorption and half-life of cortisol in the circulation play important roles in determining overall exposure to oral glucocorticoid. Dose regimens need to incorporate estimates of these parameters into determining the optimum dosing schedule for individuals.
Assuntos
Hiperplasia Suprarrenal Congênita/tratamento farmacológico , Glucocorticoides/administração & dosagem , Glucocorticoides/farmacocinética , Hidrocortisona/administração & dosagem , Hidrocortisona/sangue , Hidrocortisona/farmacocinética , Administração Oral , Adolescente , Hiperplasia Suprarrenal Congênita/sangue , Criança , Esquema de Medicação , Feminino , Glucocorticoides/sangue , Meia-Vida , Humanos , Masculino , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Primary Generalized Glucocorticoid Resistance or Chrousos syndrome is a rare genetic condition characterized by end-organ insensitivity to glucocorticoids owing to inactivating mutations of the NR3C1 gene. MATERIALS AND METHODS: We conducted a systematic review of the published, peer-reviewed medical literature using MEDLINE (1975 through November 2014) to identify original articles and reviews on this topic. The search terms included 'primary generalized glucocorticoid resistance', 'Chrousos syndrome', 'glucocorticoid receptor gene' and 'glucocorticoid receptor mutations'. RESULTS: Only a few cases of Chrousos syndrome have been described to date, ranging from asymptomatic to severe forms of mineralocorticoid and/or androgen excess. All reported cases have been associated with point mutations or deletions in the NR3C1 gene. The tremendous progress of molecular biology has enabled us to apply standard methods to investigate the molecular mechanisms of action of the mutant glucocorticoid receptors (GRs). We and others have identified and functionally characterized novel mutations causing Chrousos syndrome, while structural biology has enabled us to have a better understanding of how conformational changes of the receptor cause glucocorticoid resistance. In this review, we also present our results of the functional characterization of two recently described mutations, and we discuss the diagnostic approaches and therapeutic management of patients with Chrousos syndrome. CONCLUSIONS: Although Chrousos syndrome is a rare condition, many clinical cases remain unrecognized for a long time. We recommend determination of the 24-h urinary free cortisol excretion and sequencing of the NR3C1 gene in patients with hyperandrogenism and/or hypertension of unknown origin.
Assuntos
Erros Inatos do Metabolismo/genética , Receptores de Glucocorticoides/deficiência , Hormônio Adrenocorticotrópico/sangue , Dexametasona/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Hidrocortisona/sangue , Hidrocortisona/urina , Erros Inatos do Metabolismo/diagnóstico , Erros Inatos do Metabolismo/tratamento farmacológico , Mutação , Receptores de Glucocorticoides/genéticaRESUMO
BACKGROUND: Natural mutations in the human glucocorticoid receptor (hGR, NR3C1) gene cause Chrousos syndrome, a rare condition characterized by generalized, partial, target-tissue insensitivity to glucocorticoids. OBJECTIVE: To present a new case of Chrousos syndrome caused by a novel mutation in the hGR gene, and to elucidate the molecular mechanisms through which the natural mutant receptor affects glucocorticoid signal transduction. DESIGN AND RESULTS: The index case presented with hirsutism, acne, alopecia, anxiety, fatigue and irregular menstrual cycles, but no clinical manifestations suggestive of Cushing's syndrome. Endocrinologic evaluation revealed elevated 08:00 h plasma adrenocorticotropic hormone, serum cortisol and androstenedione concentrations and increased urinary free cortisol excretion. The patient harbored a novel A > G transition at nucleotide position 2177, which resulted in histidine (H) to arginine (R) substitution at amino acid position 726 of the receptor (c.2177A > G, p.H726R). Compared with the wild-type receptor, the mutant receptor hGRαH726R demonstrated decreased ability to transactivate glucocorticoid-responsive genes and to transrepress the nuclear factor-κB signalling pathway, displayed 55% lower affinity for the ligand and a four-fold delay in nuclear translocation, and interacted with the glucocorticoid receptor-interacting protein 1 coactivator mostly through its activation function-1 domain. Finally, a 3-dimensional molecular modelling study of the H726R mutation revealed a significant structural shift in the rigidity of helix 10 of the receptor, which resulted in reduced flexibility and decreased affinity of the mutant receptor for binding to the ligand. CONCLUSIONS: The natural mutant receptor hGRαH726R impairs multiple steps of glucocorticoid signal transduction, thereby decreasing tissue sensitivity to glucocorticoids.
Assuntos
Erros Inatos do Metabolismo/genética , Receptores de Glucocorticoides/deficiência , Acne Vulgar/genética , Adulto , Alopecia/genética , Animais , Ansiedade/genética , Western Blotting , Células COS , Chlorocebus aethiops , Fadiga/genética , Feminino , Regulação da Expressão Gênica , Genótipo , Hirsutismo/genética , Humanos , Distúrbios Menstruais/genética , Modelos Moleculares , Simulação de Acoplamento Molecular , Mutação , Receptores de Glucocorticoides/genética , SíndromeRESUMO
BACKGROUND: Transient generalized glucocorticoid hypersensitivity is a rare disorder characterized by increased tissue sensitivity to glucocorticoids and compensatory hypo-activation of the hypothalamic-pituitary-adrenal axis. The condition itself and the underlying molecular mechanisms have not been elucidated. OBJECTIVE: To present the clinical manifestations, endocrinologic evaluation and transcriptomic profile in a patient with transient generalized glucocorticoid hypersensitivity. DESIGN AND RESULTS: A 9-year-old girl presented with an 8-month history of clinical manifestations suggestive of Cushing syndrome. Endocrinologic evaluation revealed undetectable 08:00 h ACTH (<1 pg/mL) and cortisol (0·025 µg/dL) concentrations, which remained decreased throughout the 24-h period and did not respond to stimulation with ovine CRH. The disease gradually resolved spontaneously over the ensuing 3 months. Sequencing of the human glucocorticoid receptor gene revealed no mutations or polymorphisms. Western blot analysis in peripheral blood mononuclear cells revealed equal protein expression of hGRα of the patient in the disease and postresolution phases compared with a control subject. Transcriptomic analysis in peripheral blood mononuclear cells in the disease and postresolution phases identified 903 differentially expressed genes. Of these, 106 genes were up-regulated and 797 were down-regulated in the disease compared with the resolution phase. Bioinformatics analysis on the differentially expressed gene networks revealed Nuclear Factor-κB as the predominant transcription factor influencing the expression of the majority of differentially expressed genes. CONCLUSIONS: Our findings indicate that a transient postreceptor defect, or a virus- or bacterium-encoded molecule, may have enhanced glucocorticoid signal transduction, leading to transient generalized glucocorticoid hypersensitivity and hypo-activation of the HPA axis.