121 research outputs found

    Human Glucocorticoid Receptor β Regulates Gluconeogenesis and Inflammation in Mouse Liver

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    Whilein vitrostudies have demonstrated that a glucocorticoid receptor (GR) splice isoform, β-isoform of human GR (hGRβ), acts as a dominant-negative inhibitor of the classic hGRα and confers glucocorticoid resistance, thein vivofunction of hGRβ is poorly understood. To this end, we created an adeno-associated virus (AAV) to express hGRβ in the mouse liver under the control of the hepatocyte-specific promoter. Genome-wide expression analysis of mouse livers showed that hGRβ significantly increased the expression of numerous genes, many of which are involved in endocrine system disorders and the inflammatory response. Physiologically, hGRβ antagonized GRα's function and attenuated hepatic gluconeogenesis through downregulation of phosphoenolpyruvate carboxykinase (PEPCK) in wild-type (WT) mouse liver. Interestingly, however, hGRβ did not repress PEPCK in GR liver knockout (GRLKO) mice. In contrast, hGRβ regulates the expression of STAT1 in the livers of both WT and GRLKO mice. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays demonstrated that hGRβ binds to the intergenic glucocorticoid response element (GRE) of the STAT1 gene. Furthermore, treatment with RU486 inhibited the upregulation of STAT1 mediated by hGRβ. Finally, our array data demonstrate that hGRβ regulates unique components of liver gene expressionin vivoby both GRα-dependent and GRα-independent mechanisms

    Establecimiento de las ventajas de las redes sociales como estrategia de comercialización en las empresas del sector servicios de fumigación

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    The main objective of this work is to "identify whether factors such as social networks, periodicity and offers obtained sales in the fumigation services sector", thanks to the results obtained and the analysis prepared, the objectives could be achieved and reaffirmed. According to the objective that was raised at the beginning, such as identifying by applying descriptive statistical methods and factor analysis, the main relationships that exist between social networks, the periodicity and the offers with the increase in sales of the fumigation companies in the state of Colima. With the results obtained and the study carried out, the hypotheses could be verified, by establishing a significant correlation with each of the independent variables such as social networks, periodicity and offers, verifying that they are essential factors to achieve increased sales in the fumigation companies. Therefore, the independent variables such as social networks, periodicity and offers have a significant correlation and it is 100% fulfilled based on the factor analysis that was done for this type of study, culminating with the formula that was obtained when doing this analysis. factorial: formula y = a + xb so each increase in coefficient B will show a proportional increase in the other variables.El presente trabajo tiene como principal objetivo “identificar si los factores como las redes sociales, la periodicidad y las ofertas aumentan las ventas del sector servicios de fumigación”, gracias a los resultados obtenidos y el análisis elaborado se pudieron lograr los objetivos y reafirmarlos. De acuerdo al objetivo que se planteó al inicio tal como identificar aplicando métodos estadísticos descriptivos y análisis factoriales, las principales relaciones que existen entre las redes sociales, la periodicidad y  las ofertas con el aumento de ventas de las empresas de fumigación en el estado de Colima. Con los resultados obtenidos y el estudio realizado se pudieron comprobar las hipotesis, al establecer una correlación significativa con cada una de las variables independientes como redes sociales, periodicidad y ofertas, comprobando que son factores esenciales para lograr aumentar las ventas en las empresas de fumigación. Por lo tanto las variables independientes tales como redes sociales, periodicidad y  ofertas tienen una correlación significativa y se cumple en un 100%  con base al análisis factorial que se hizo para este tipo de estudio, culminando con la fórmula que se obtuvo al hacer este análisis factorial: fórmula y=a+xb por lo que cada que aumente el coeficiente B se verá un aumento proporcional de las demás variables

    Corticosteroids Are Essential for Maintaining Cardiovascular Function in Male Mice

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    Activation of the hypothalamic-pituitary-adrenal axis results in the release of hormones from the adrenal glands, including glucocorticoids and mineralocorticoids. The physiological association between corticosteroids and cardiac disease is becoming increasingly recognized; however, the mechanisms underlying this association are not well understood. To determine the biological effects of corticosteroids on the heart, we investigated the impact of adrenalectomy in C57BL/6 male mice. Animals were adrenalectomized (ADX) at 1 month of age and maintained for 3–6 months after surgery to evaluate the effects of long-term adrenalectomy on cardiac function. Morphological evaluation suggested that ADX mice showed significantly enlarged hearts compared with age-matched intact controls. These changes in morphology correlated with deficits in left ventricular (LV) function and electrocardiogram (ECG) abnormalities in ADX mice. Correlating with these functional defects, gene expression analysis of ADX hearts revealed aberrant expression of a large cohort of genes associated with cardiac hypertrophy and arrhythmia. Combined corticosterone and aldosterone replacement treatment prevented the emergence of cardiac abnormalities in ADX mice, whereas corticosterone replacement prevented the effects of adrenalectomy on LV function but did not block the emergence of ECG alterations. Aldosterone replacement did not preserve the LV function but prevented ECG abnormalities. Together, the data indicate that adrenal glucocorticoids and mineralocorticoids either directly or indirectly have selective effects in the heart and their signaling pathways are essential in maintaining normal cardiac function

    Essential role of stress hormone signaling in cardiomyocytes for the prevention of heart disease

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    Stress is increasingly associated with heart disease. Glucocorticoids are primary stress hormones, yet their direct role in the heart is poorly understood. Mice lacking the glucocorticoid receptor specifically in cardiomyocytes die prematurely from heart failure. The deficiency in glucocorticoid signaling leads to the aberrant regulation of a large cohort of genes strongly associated with both cardiovascular and inflammatory disease processes. These findings reveal an obligate role for cardiomyocyte glucocorticoid receptors in maintaining normal heart function and define a paradigm for stress in cardiovascular disease

    Glucocorticoid receptor alters isovolumetric contraction and restrains cardiac fibrosis

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    Corticosteroids directly affect the heart and vasculature and are implicated in the pathogenesis of heart failure. Attention is focussed upon the role of the mineralocorticoid receptor (MR) in mediating pro-fibrotic and other adverse effects of corticosteroids upon the heart. In contrast, the role of the glucocorticoid receptor (GR) in the heart and vasculature is less well understood. We addressed this in mice with cardiomyocyte and vascular smooth muscle deletion of GR (SMGRKO mice). Survival of SMGRKO mice to weaning was reduced compared with that of littermate controls. Doppler measurements of blood flow across the mitral valve showed an elongated isovolumetric contraction time in surviving adult SMGRKO mice, indicating impairment of the initial left ventricular contractile phase. Although heart weight was elevated in both genders, only male SMGRKO mice showed evidence of pathological cardiomyocyte hypertrophy, associated with increased myosin heavy chain-β expression. Left ventricular fibrosis, evident in both genders, was associated with elevated levels of mRNA encoding MR as well as proteins involved in cardiac remodelling and fibrosis. However, MR antagonism with spironolactone from birth only modestly attenuated the increase in pro-fibrotic gene expression in SMGRKO mice, suggesting that elevated MR signalling is not the primary driver of cardiac fibrosis in SMGRKO mice, and cardiac fibrosis can be dissociated from MR activation. Thus, GR contributes to systolic function and restrains normal cardiac growth, the latter through gender-specific mechanisms. Our findings suggest the GR:MR balance is critical in corticosteroid signalling in specific cardiac cell types

    Cardiomyocyte glucocorticoid and mineralocorticoid receptors directly and antagonistically regulate heart disease in mice

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    Stress is increasingly associated with heart dysfunction and is linked to higher mortality rates in patients with cardiometabolic disease. Glucocorticoids are primary stress hormones that regulate homeostasis through two nuclear receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), both of which are present in cardiomyocytes. To examine the specific and coordinated roles that these receptors play in mediating the direct effects of stress on the heart, we generated mice with cardiomyocyte-specific deletion of GR (cardioGRKO), MR (cardioMRKO), or both GR and MR (cardioGRMRdKO). The cardioGRKO mice spontaneously developed cardiac hypertrophy and left ventricular systolic dysfunction and died prematurely from heart failure. In contrast, the cardioMRKO mice exhibited normal heart morphology and function. Surprisingly, despite the presence of myocardial stress, the cardioGRMRdKO mice were resistant to the cardiac remodeling, left ventricular dysfunction, and early death observed in the cardioGRKO mice. Gene expression analysis revealed the loss of gene changes associated with impaired Ca2+ handling, increased oxidative stress, and enhanced cell death and the presence of gene changes that limited the hypertrophic response and promoted cardiomyocyte survival in the double knockout hearts. Re-expression of MR in cardioGRMRdKO hearts reversed many of the cardioprotective gene changes and resulted in cardiac failure. These findings reveal a critical role for balanced cardiomyocyte GR and MR stress signaling in cardiovascular health. Therapies that shift stress signaling in the heart to favor more GR and less MR activity may provide an improved approach for treating heart disease

    Getting to the heart of intracellular glucocorticoid regeneration:11β-HSD1 in the myocardium

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    Corticosteroids influence the development and function of the heart and its response to injury and pressure overload via actions on glucocorticoid (GR) and mineralocorticoid (MR) receptors. Systemic corticosteroid concentration depends largely on the activity of the hypothalamic–pituitary–adrenal (HPA) axis, but glucocorticoid can also be regenerated from intrinsically inert metabolites by the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), selectively increasing glucocorticoid levels within cells and tissues. Extensive studies have revealed the roles for glucocorticoid regeneration by 11β-HSD1 in liver, adipose, brain and other tissues, but until recently, there has been little focus on the heart. This article reviews the evidence for glucocorticoid metabolism by 11β-HSD1 in the heart and for a role of 11β-HSD1 activity in determining the myocardial growth and physiological function. We also consider the potential of 11β-HSD1 as a therapeutic target to enhance repair after myocardial infarction and to prevent the development of cardiac remodelling and heart failure
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