A privação dos hormônios sexuais em fêmeas contribui para o aparecimento de distúrbios metabólicos e endócrinos devido à ausência de estrógenos. Nesse estudo foi avaliado o efeito da castração e da suplementação com DHEA sobre aspectos metabólicos em ratas. A ovariectomia aumentou a adiposidade e o consumo de ração, diminuiu o consumo hídrico, além de promover resistência à insulina e intolerância à glicose, e o uso do DHEA reduziu a sensibilidade à insulina. Ainda, a castração levou a redução nos níveis plasmáticos de DHEA, estradiol, VLDL-c e triacilglicerol, albumina, uréia e creatinina, e o tratamento com DHEA restaurou parcialmente a concentração de estradiol no grupo OVX+DHEA. E por fim, a ooforectomia reduziu a expressão proteica do IRb, IRS1, PI3K e AKT no fígado, músculo gastrocnêmio ou coração, além diminuir o grau de fosforilação em tirosina da pp185 (IRS1/2). Deste modo, concluímos que a castração promoveu resistência à insulina e intolerância à glicose associada à obesidade, e neste modelo, o uso do DHEA piorou a sensibilidade à insulina nos animais. / Deprivation of sex hormones in females contributes to the onset of metabolic and endocrine disorders due loss of estrogen. In this study the effect of castration and supplementation with DHEA on metabolic aspects in rats was evaluated. Ovariectomy increased adiposity and food consumption, decreased water consumption, besides promoting insulin resistance and glucose intolerance, and the use of DHEA reduced insulin sensitivity. Furthermore, castration led to decreasing of DHEA plasma levels, estradiol, VLDL-c and triacylglycerol, albumin, urea and creatinine, and DHEA treatment partially restored the concentration of estradiol in OVX+DHEA group. Finally, ovariectomy reduced the protein expression IRb, IRS1, PI3K and AKT in the liver, gastrocnemius muscle or heart. Indeed, decrease tyrosine phosphorylation status of pp185 (IRS1/2) was observed. Thus, we conclude that castration promoted insulin resistance and glucose intolerance associated with obesity, and in this model, the use of DHEA impairs insulin sensitivity in animals.

A redução dos hormônios gonadais seja pelo processo natural de falência folicular denominado nas humanas de menopausa, seja pela ooforectomia, está associado com aumento da incidência de doença cardiovascular em mulheres no período pós menopausa. O objetivo desse estudo é avaliar o efeito da ooforectomia e a suplementação com DHEA sobre a morfologia dos cardiomiócitos, a expressão de proteínas celulares envolvidas com crescimento e apoptose celular e a função cardíaca. A ooforectomia induz maior ganho de massa corporal e do coração, no entanto, a avaliação morfológica do VE mostrou que há uma redução da espessura dos cardiomiócitos e do número de núcleos. Ademais, o immunoblotting demonstrou uma diminuição na expressão das proteínas IR, IRS1 e AKT nos corações das ratas ooforectomizadas e os parâmetros hemodinâmicos foram semelhantes entre os grupos. O tratamento com DHEA reverteu a redução do número de núcleos sem interferir nos demais parâmetros avaliados. Os dados obtidos nos permite concluir que a ausência dos esteroides gonadais por si só resulta em modificações morfológicas dos cardiomiócitos que podem estar relacionados ao processo de apoptose sem afetar a função de bomba do coração e o uso do DHEA é capaz de reverter a redução numérica dos núcleos. / The reduction of gonadal hormones by menopause, the natural process of failure in the human follicle, or by surgical removal, is associated with increased incidence of cardiovascular disease in postmenopause women. The aim of this study is to evaluate the effect of oophorectomy and the DHEA supplementation on the morphology of cardiomyocytes, on the expression of proteins involved in cell growth, on apoptosis (IGF-1R, IR, IRS-1, PI3K, AKT, MAPKp42/44, JAK2) and on the cardiac function. Oophorectomy enhances both the body mass e heart weight, however the left ventricle showed a reduction in cardiomyocyte thickness by 15% and in the number of nuclei by 20%. Moreover the immunoblotting showed a decrease from 25 to 50% in the expression of IR, IRS-1 and AKT proteins in the hearts of oophorectomized rats. The hemodynamic parameters were similar between groups. Treatment with DHEA reversed the reduction in the number of nuclei with no change in the other parameters evaluated. Our data allow us to conclude that the absence of gonadal steroids per se induces morphological changes in the cardiomyocytes that may be related to apoptosis with no change on the heart pump function. The DHEA supplementation is able to reverse the reduced number of nuclei.

Orientador: Artur Torres Cordeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T07:11:05Z (GMT). No. of bitstreams: 1 Ranzani_AmericoTavares_M.pdf: 3887425 bytes, checksum: 3ae590890f0f321ec227cb9c0967c6de (MD5) Previous issue date: 2013 / Resumo: Tripanossomíases são enfermidades associadas à infecção por protozoários do gênero Trypanosoma. Estas doenças são normalmente tratadas com medicamentos de alta toxicidade e baixa eficiência. A pesquisa de novos compostos que atuem de maneira específica contra alvos metabólicos pré-estabelecidos pode levar ao desenvolvimento de fármacos mais eficientes no tratamento destas enfermidades. A enzima glicose-6-fosfato desidrogenase (G6PD) é um alvo metabólico validado experimentalmente em Trypanosoma brucei. A G6PD catalisa o primeiro passo da via de síntese de pentoses que supre a célula com ribose-5-fosfato para síntese de bases nitrogenadas e NADPH para biosíntese de lípideos, colesterol e neutralização de espécies reativas de oxigênio. O esteróide desidroepiandrosterona (DHEA) e seus análogos são conhecidos inibidores incompetitivos da enzima humana e recentemente foram caracterizados também como potentes inibidores da G6PD de T. brucei e T. cruzi. Estes esteróides também apresentam efeito citotóxico à forma sanguínea de T. brucei e à forma epimastigota de T. cruzi. Em conjunto, estes resultados sugerem que esteróides análogos do DHEA devam ser explorados como uma nova classe de fármacos antiparasitários. Apesar de já haver estruturas da enzima, o sítio de ligação destes esteróides não é conhecido, informação que ajudaria no desenho racional de novos inibidores. Assim, este projeto teve como objetivo principal a identificação do sítio de inibição por cristalografia. Conseguiu-se estabelecer um protocolo de expressão, purificação e cristalização para a G6PD humana. Testou-se a co-cristalização, seeding e soaking com os esteróides DHEA, epiandrosterona (EA) e 16-bromo-epiandrosterona (16BrEA) com os substratos da enzima, além de outros complexos com frutose-6-fosfato, glucosamina-6-fosfato e NADPH. Na tentativa de diminuir a atividade da enzima para facilitar a cristalização com os substratos e os esteróides, fez-se o mutante D200N, que além de ser menos ativo, também apresentou uma menor inibição pelos esteróides. A enzima humana se apresenta como um equilíbrio de dímero e tetrâmero, não se sabendo a influência destes estados na atividade da enzima. Assim, para favorecer somente um estado oligomérico, foram avaliadas mutações na interface do tetrâmero. A mutação A277C permite a formação de uma ponte dissulfeto com a C294, estabilizando o tetrâmero. A mutação E347A é capaz de desestabilizar o tetrâmero, favorecendo a forma dimérica. Embora não tenha sido possível obter a estrutura da enzima com os esteróides, conseguiu-se pela primeira vez apontar para um resíduo importante para a inibição, o que abre oportunidade para investigações futuras que podem levar à descrição do sítio de inibição / Abstract: Trypanosomiases are infectious diseases caused by protozoan parasites from genus Trypanosoma. Such diseases are currently treated with low effective and highly toxic drugs. The research of novel compounds which inhibits validated metabolic targets might lead to the development of more efficient drugs to such neglected diseases. The enzyme glucose-6-phosphate dehydrogenase (G6PD) was experimentally validated as a metabolic target in T. brucei bloodstream form. G6PD catalyzes the first step of the pentose phosphate pathway (PPP), which supplies the cell with ribose-5-phosphate for synthesis of nucleotides and NADPH for biosynthesis of lipids, cholesterol and detoxification of reactive oxygen species. The steroid Dehydroepiandrosterone (DHEA) and analogues are known uncompetitive inhibitors of the human G6PD and recently they were also characterized as potent inhibitors of T. brucei and T. cruzi G6PD. It was also demonstrated that these steroids are toxic to cultured T. brucei bloodstream form and T. cruzi epimastigote form. Together these results suggest that DHEA derivatives must be explored as a novel anti-parasite drug class. Although the structure of the enzyme is solved, the binding site of these steroids is unknown, information that would help in the rational design of new inhibitors. So, the main goal of this project was the identification of the inhibition site by crystallography. It was established an expression, purification and crystallization protocol for the human G6PD. It was tried the co-crystallization, seeding and soaking of the steroids DHEA, epiandrosterone (EA) and 16-bromo-epiandrosterone (16BrEA) with the substrates of the enzyme, beyond other complexes with fructose-6-phosphate, glucosamine-6-phosphate and NADPH. Attempting to diminish the enzyme activity to facilitate the crystallization with the substrates and the steroids, it was made the mutant D200N, which not only is less active, but it's also less inhibited by the steroids. The human enzyme is in equilibrium between dimer and tetramer, being unknown the effect of these states to the enzyme activity. This way, to favor one oligomer state, it was assessed mutations at the tetramer interface. The mutation A277C allows the formation of a disulfide bond with the C294, stabilizing the tetramer. The mutation E347A is able to destabilize the tetramer, favoring the dimer. Although it was not possible to determine the structure of the enzyme with the steroids, for the first time it was shown the involvement of a residue in the steroid inhibition, which makes possible future investigations that can lead to the inhibition site description / Mestrado / Fármacos, Medicamentos e Insumos para Saúde / Mestre em Biociências e Tecnologia de Produtos Bioativos

As Doenças inflamatórias intestinais (DII) são multifatoriais e sua etiologia envolve susceptibilidade genética, fatores ambientais, disbiose e ativação exacerbada do sistema imunológico no intestino. Essas doenças também tem sido relacionadas a baixos níveis de dehidroepiandrosterona (DHEA), um hormônio precursor de diversos esteroides e relacionado à modulação das respostas imunes. Porém, os mecanismos precisos que relacionam as ações deste hormônio com a proteção ou susceptibilidade à doença de Crohn ou colite ulcerativa ainda não são totalmente conhecidos. Sendo assim, este projeto buscou entender o papel imunomodulador do DHEA exógeno in vitro e in vivo durante a inflamação intestinal experimental induzida por dextran sulfato de sódio (DSS) em camundongos C57BL/6. Inicialmente, in vitro, DHEA inibiu a proliferação de células do baço de forma dose dependente nas concentrações de 5?M, 50?M ou 100?M, com diminuição da produção de IFN-?. Este hormônio não foi tóxico para células de linhagem mieloide, embora tenha causado necrose em leucócitos nas doses mais elevada (50 ?M e 100?M), o que pode ter influenciado a diminuição das citocinas in vitro. Nos ensaios in vivo, os camundongos tratados com DHEA (40 mg/Kg) foram avaliados na fase de indução da doença (dia 6) e durante o reparo tecidual, quando os animais expostos ao DSS e ao DHEA por 9 dias foram mantidos na ausência destas drogas até o dia 15. Houve diminuição do escore pós-morte, melhora no peso e nos sinais clínicos da inflamação intestinal, com redução de monócitos no sangue periférico com 6 dias e aumento de neutrófilos circulantes na fase de reparo tecidual (15 dias). Ainda, a suplementação com DHEA levou à redução da celularidade da lâmina própria (LP) e ao restabelecimento do comprimento normal do intestino. O uso deste hormônio também diminuiu a expressão do RNAm de IL-6 e TGF-?, enquanto aumentou a expressão de IL-13 no colón dos animais durante a fase de indução da doença, o que provavelmente ajudou na atenuação da inflamação intestinal. Além disso, houve acúmulo de linfócitos CD4+ e CD8+ no baço e diminuição apenas de linfócitos CD4+ nos linfonodos mesentéricos (LNM), indicando retenção das células CD4+ no baço após uso do DHEA. O tratamento foi também capaz de aumentar a frequência de células CD4 produtoras de IL-4 e diminuir CD4+IFN-?+ no baço, além de reduzir a frequência de CD4+IL-17+ nos LNM, sugerindo efeito do DHEA no balanço das respostas Th1/Th2/Th17 relacionadas à colite. Em adição, as células de baço dos animais tratados com DHEA e expostos ao DSS se tornaram hiporresponsivas, como visto pela diminuição da proliferação após re-estímulos in vitro. Finalmente, DHEA foi capaz de atuar no metabolismo dos camundongos tratados, levando à diminuição de colesterol total e da fração LDL no soro durante a fase de indução da doença, sem gerar quaisquer disfunções hepáticas. Com isso, podemos concluir que o DHEA atua por meio do balanço das respostas imunes exacerbadas, minimizando os danos locais e sistêmicos causados pela inflamação intestinal induzida por DSS. / Inflammatory bowel diseases (IBD) are multifactorial diseases whose etiology involves genetic susceptibility, environmental factors, dysbiosis and exacerbated activation of the immune system in the gut. These diseases have also been associated to lower levels of dehydroepiandrosterone (DHEA), a precursor of various steroid hormones, related to modulation of immune responses. However, the precise mechanisms that link the actions of this hormone with protection or susceptibility to Crohn\'s disease or ulcerative colitis are still not fully understood. Thus, this project aimed to understand the immunomodulatory role of exogenous DHEA in vitro and in vivo in experimental intestinal inflammation induced by dextran sodium sulfate (DSS) in C57BL/6 mice. Initially, in vitro, DHEA inhibited the proliferation of spleen cells in a dose dependent way on the concentrations of 5?M, 50?M and 100?M, with decreased production of IFN-?. This hormone was not toxic to myeloid lineage cells, although it caused necrosis of leukocytes at the highest doses (50?M and 100?M), which may have influenced the decrease of the cytokines in vitro. Mice treated with DHEA (40 mg / kg) were evaluated at the induction phase of the disease (day 6) and during tissue repair, when animals exposed to DSS and DHEA for 9 days were maintained in the absence these drugs until the day 15. There was decrease of postmortem score, improved weight and clinical signs of intestinal inflammation, besides reduced peripheral blood monocytes on day 6, together with an increase in circulating neutrophils in tissue repair phase (15 days). Supplementation with DHEA also led to a reduction in cellularity of the lamina propria (LP) and to the restoration of normal length of the gut. The use of this hormone also decreased the expression of of IL-6 and TGF-? mRNA, while IL-13 was augmented in the colon of mice during the induction phase of the disease, a fact probably related to attenuation of intestinal inflammation. Furthermore, there was accumulation of CD4+ and CD8+ cells in the spleen along with decreased CD4+ leukocytes in mesenteric lymph nodes (MLN), indicating retention of CD4+ cells in the spleen after use of DHEA. The treatment was also able to increase the frequency of CD4+ cells producing IL-4 and decrease CD4+IFN-?+ in spleen, with reduced frequency of CD4+IL-17+ in the MLN, suggesting a role for DHEA on the balance of Th1/Th2/Th17 responses related colitis. In addition, splenocytes of mice treated with DHEA and exposed to DSS became hiporresponsives as seen by decreased proliferation after re-stimulation in vitro. Finally, DHEA was able to act on the metabolism of treated mice, leading to decreased total cholesterol and LDL cholesterol in serum during the induction phase of the disease, without generating any liver dysfunction. Thus, we concluded that DHEA acts by balancing the exacerbated immune responses, minimizing local and systemic damages caused by intestinal inflammation induced by DSS.

Com o envelhecimento observa-se redução da massa muscular, aumento da resistência à insulina e queda nos níveis séricos de alguns hormônios, entre eles o DHEA. Ratos com 12-14 meses de idade apresentam regulação músculo-específica em vias da insulina e IGF 1 em músculos com populações distintas de tipos de fibras e como indicador de sarcopenia apresentam redução da proporção e tamanho de fibras tipo 2b. Dose única de DHEA não modula as vias da insulina e IGF 1 no músculo esquelético e reduz tamanho de fibras tipo 1 no EDL. / Reductions in skeletal muscle mass, increased insulin resistance, and decrements in several hormones serum levels, including DHEA, are features observed in aging. Twelve to fourteen months old rats present specific regulation in the insulin and the IGF-1 intracellular pathway in distinct skeletal muscle fiber composition and show reductions in size and proportion of muscle composed predominantly by fiber type 2. DHEA treatment had no effect in these intracellular pathways but induces reduction in the size of type 1 fiber in the EDL muscle.

Objective To determine the relationship between increased body hair growth in women and serum sex hormone level, body mass index, and clinical signs. Sample and methods The sample group consisted of 186 women, 18–35 year old residents of Lithuania who were referred to the Clinic of Endocrinology, Kaunas University of Medicine Hospital in 2002–2004 and complained for increased body hair growth. Exclusion criteria: 1) taking systemic medications within the period shorter than three months before the beginning of the study; 2) specific reasons of excessive body hair growth, such as androgen secreting adrenal or ovarian tumors, hyperprolactinemia, Cushing syndrome; 3) thyroid dysfunction. A total number of 37 women were excluded from further study. Statistical analysis was performed on 149 women. Increased body hair growth was assessed using Ferriman-Gallwey (F-G) method. Blood samples were drawn in the morning (08:00–10:00 h), in the early follicular phase, with an exclusion of 7 women with amenorrhea, while the blood sample of 12 women with oligomenorrhea was drawn following at least 2 months after the last menstruation. Serum hormones (total testosterone (T), sex hormone binding globulin (SHBG), free androgen index (FAI), dehydroepiandrosterone sulphate (DHEAS) level were measured using the commercial kits. FAI was calculated as follows: T (nmol/l) × 100/ SHBG (nmol/l). Results The significance of correlations between the F-G score and the tested variables decreased in the... [to full text]

Com o envelhecimento observa-se redução da massa muscular, aumento da resistência à insulina e queda nos níveis séricos de alguns hormônios, entre eles o DHEA. Ratos com 12-14 meses de idade apresentam regulação músculo-específica em vias da insulina e IGF 1 em músculos com populações distintas de tipos de fibras e como indicador de sarcopenia apresentam redução da proporção e tamanho de fibras tipo 2b. Dose única de DHEA não modula as vias da insulina e IGF 1 no músculo esquelético e reduz tamanho de fibras tipo 1 no EDL. / Reductions in skeletal muscle mass, increased insulin resistance, and decrements in several hormones serum levels, including DHEA, are features observed in aging. Twelve to fourteen months old rats present specific regulation in the insulin and the IGF-1 intracellular pathway in distinct skeletal muscle fiber composition and show reductions in size and proportion of muscle composed predominantly by fiber type 2. DHEA treatment had no effect in these intracellular pathways but induces reduction in the size of type 1 fiber in the EDL muscle.

Although the link between androgens and depression is well established in adults, the effects of cofactors on this association are less clearly understood, particularly in youth. Epidemiological cohort study of adolescents in Dresden, Germany. Analyses comprised data of 985 individuals assessed at baseline and of 512 individuals at 1-year follow-up. We investigated multivariable regression models for cross-sectional and longitudinal associations of hair testosterone, dehydroepiandrosterone (DHEA), and their cortisol ratios with 12-month diagnoses of major depressive disorder (MDD) and MDD without any anxiety disorder assessed with standardized diagnostic interview (DIA-X-5), and with dimensional depression scores (PHQ-9, PROMIS), separately for males and females. The potential moderating effect of social support was determined. Cross-sectional analyses yielded inverse associations of testosterone and DHEA with MDD and MDD without any anxiety disorders in males. In cross-sectional and longitudinal analyses, baseline ratio cortisol/DHEA was significantly, inversely associated to PROMIS-depression in males. Only cross-sectional associations for ratio cortisol/DHEA and PROMIS-depression remained significant after Bonferroni-Holm correction. No robust associations were observed in female participants. Social support exerted no consistent moderating effect on the investigated association. The present observational cohort study showed no consistent association of hair androgen concentrations with depressive disorders in adolescents. However, findings provide some support for the association between the cortisol/DHEA ratio and depression in males. Longitudinal research designs in large samples are needed to understand the interplay between androgens, depression, and developmental and social factors in youth.

<p>Autoimmune mechanisms and genetic susceptibility contribute to the pathogenesis of primary Sjögren’s syndrome and SLE. These chronic systemic autoimmune diseases have many serological and clinical features in common and have an impact on daily life. The studies in this thesis aim to elucidate their autoimmune mechanisms, define susceptibility genes and evaluate effects of androgen supplement on health-related quality of life.</p><p>Autoantibodies against α-fodrin, a widely distributed cytoskeletal protein, were detected at similar frequencies in sera from patients with primary and secondary Sjögren’s syndrome and SLE. Consequently, testing for antibodies against α-fodrin would not add diagnostic value compared to conventional serological analysis and does not discriminate between these diseases.</p><p>The type I interferon (IFN) system was found to be activated in primary Sjögren’s syndrome. IFN-α containing cells were detected in minor salivary gland biopsies, while sera from patients with primary Sjögren’s syndrome induced IFN-α production in the presence of apoptotic and necrotic cell material. This ability of sera correlated with the presence of antibodies against RNA-binding proteins and IFN-α production was dependent on RNA in immune complexes. The natural interferon producing cells/plasmacytoid dendritic cells (NIPC/PDC) were the IFN-α producers and blocking of FcγRIIa inhibited the production. Single nucleotide polymorphisms (SNPs) in two genes in the type I IFN signalling pathway, those for tyrosine kinase 2 and interferon regulatory factor 5, were strongly associated with SLE in a Swedish, Finnish and Icelandic population. The minor allele frequencies were lower in SLE patients than in healthy controls. These SNPs may decrease the function of the type I IFN system, thereby conferring protection against SLE. </p><p>Supplementation with dehydroepiandrosterone (DHEA) in glucocorticoid treated women with SLE led to mild improvements in health-related quality of life in respect of mental well-being and sexuality, whereas physical well-being was unaffected.</p>

Autoimmune mechanisms and genetic susceptibility contribute to the pathogenesis of primary Sjögren’s syndrome and SLE. These chronic systemic autoimmune diseases have many serological and clinical features in common and have an impact on daily life. The studies in this thesis aim to elucidate their autoimmune mechanisms, define susceptibility genes and evaluate effects of androgen supplement on health-related quality of life. Autoantibodies against α-fodrin, a widely distributed cytoskeletal protein, were detected at similar frequencies in sera from patients with primary and secondary Sjögren’s syndrome and SLE. Consequently, testing for antibodies against α-fodrin would not add diagnostic value compared to conventional serological analysis and does not discriminate between these diseases. The type I interferon (IFN) system was found to be activated in primary Sjögren’s syndrome. IFN-α containing cells were detected in minor salivary gland biopsies, while sera from patients with primary Sjögren’s syndrome induced IFN-α production in the presence of apoptotic and necrotic cell material. This ability of sera correlated with the presence of antibodies against RNA-binding proteins and IFN-α production was dependent on RNA in immune complexes. The natural interferon producing cells/plasmacytoid dendritic cells (NIPC/PDC) were the IFN-α producers and blocking of FcγRIIa inhibited the production. Single nucleotide polymorphisms (SNPs) in two genes in the type I IFN signalling pathway, those for tyrosine kinase 2 and interferon regulatory factor 5, were strongly associated with SLE in a Swedish, Finnish and Icelandic population. The minor allele frequencies were lower in SLE patients than in healthy controls. These SNPs may decrease the function of the type I IFN system, thereby conferring protection against SLE. Supplementation with dehydroepiandrosterone (DHEA) in glucocorticoid treated women with SLE led to mild improvements in health-related quality of life in respect of mental well-being and sexuality, whereas physical well-being was unaffected.