RESUMEN
Nuclear receptors play a central role in both energy metabolism and cardiomyocyte death and survival in the heart. Recent evidence suggests they may also influence cardiomyocyte endowment. Although several members of the nuclear receptor family play key roles in heart maturation (including thyroid hormone receptors) and cardiac metabolism, here, the focus will be on the corticosteroid receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). The heart is an important target for the actions of corticosteroids, yet the homeostatic role of GR and MR in the healthy heart has been elusive. However, MR antagonists are important in the treatment of heart failure, a condition associated with mitochondrial dysfunction and energy failure in cardiomyocytes leading to mitochondria-initiated cardiomyocyte death (Ingwall and Weiss, Circ Res 95:135-145, 2014; Ingwall , Cardiovasc Res 81:412-419, 2009; Zhou and Tian , J Clin Invest 128:3716-3726, 2018). In contrast, animal studies suggest GR activation in cardiomyocytes has a cardioprotective role, including in heart failure.
Asunto(s)
Insuficiencia Cardíaca , Receptores de Mineralocorticoides , Animales , Insuficiencia Cardíaca/metabolismo , Miocitos Cardíacos/metabolismo , Receptores de Glucocorticoides/fisiología , Receptores de Hormona Tiroidea/metabolismoRESUMEN
The late gestational rise in glucocorticoids contributes to the structural and functional maturation of the perinatal heart. Here, we hypothesized that glucocorticoid action contributes to the metabolic switch in perinatal cardiomyocytes from carbohydrate to fatty acid oxidation. In primary mouse fetal cardiomyocytes, dexamethasone treatment induced expression of genes involved in fatty acid oxidation and increased mitochondrial oxidation of palmitate, dependent upon a glucocorticoid receptor (GR). Dexamethasone did not, however, induce mitophagy or alter the morphology of the mitochondrial network. In vivo, in neonatal mice, dexamethasone treatment induced cardiac expression of fatty acid oxidation genes. However, dexamethasone treatment of pregnant C57Bl/6 mice at embryonic day (E)13.5 or E16.5 failed to induce fatty acid oxidation genes in fetal hearts assessed 24 h later. Instead, at E17.5, fatty acid oxidation genes were downregulated by dexamethasone, as was GR itself. PGC-1α, required for glucocorticoid-induced maturation of primary mouse fetal cardiomyocytes in vitro, was also downregulated in fetal hearts at E17.5, 24 h after dexamethasone administration. Similarly, following a course of antenatal corticosteroids in a translational sheep model of preterm birth, both GR and PGC-1α were downregulated in heart. These data suggest that endogenous glucocorticoids support the perinatal switch to fatty acid oxidation in cardiomyocytes through changes in gene expression rather than gross changes in mitochondrial volume or mitochondrial turnover. Moreover, our data suggest that treatment with exogenous glucocorticoids may interfere with normal fetal heart maturation, possibly by downregulating GR. This has implications for clinical use of antenatal corticosteroids when preterm birth is considered a possibility. KEY POINTS: Glucocorticoids are steroid hormones that play a vital role in late pregnancy in maturing fetal organs, including the heart. In fetal cardiomyocytes in culture, glucocorticoids promote mitochondrial fatty acid oxidation, suggesting they facilitate the perinatal switch from carbohydrates to fatty acids as the predominant energy substrate. Administration of a synthetic glucocorticoid in late pregnancy in mice downregulates the glucocorticoid receptor and interferes with the normal increase in genes involved in fatty acid metabolism in the heart. In a sheep model of preterm birth, antenatal corticosteroids (synthetic glucocorticoid) downregulates the glucocorticoid receptor and the gene encoding PGC-1α, a master regulator of energy metabolism. These experiments suggest that administration of antenatal corticosteroids in anticipation of preterm delivery may interfere with fetal heart maturation by downregulating the ability to respond to glucocorticoids.
Asunto(s)
Glucocorticoides , Nacimiento Prematuro , Animales , Dexametasona/farmacología , Ácidos Grasos , Femenino , Corazón Fetal , Glucocorticoides/farmacología , Ratones , Miocitos Cardíacos , Embarazo , Receptores de Glucocorticoides/genética , OvinosRESUMEN
There are few biomarkers to predict efficacy of glucocorticoid treatment in childhood acute lymphoblastic leukemia (ALL) at diagnosis. Here, we demonstrate reciprocal regulation of 11beta-hydroxysteroid dehydrogenase (11ß-HSD), may predict the apoptotic response of ALL to glucocorticoid treatment. Our data may be useful to refine glucocorticoid treatment, to retain benefit while minimizing side effects.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/fisiología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/fisiología , Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Prednisolona/uso terapéutico , Adolescente , Células Cultivadas , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Resultado del TratamientoRESUMEN
RATIONALE: The activity of the glucocorticoid activating enzyme 11ß-hydroxysteroid dehydrogenase type-1 (11ßHSD1) is altered in diseases such as obesity, inflammation and psychiatric disorders. In rodents 11ßHSD1 converts inert 11-dehydrocorticosterone (11-DHC) into the active form, corticosterone (CORT). A sensitive, specific liquid chromatography/tandem mass spectrometry method was sought to simultaneously quantify total 11-DHC and total and free CORT in murine plasma for simple assessment of 11ßHSD1 activity in murine models. METHODS: Mass spectrometry parameters were optimised and a method for the chromatographic separation of CORT and 11-DHC was developed. Murine plasma was prepared by 10:1 chloroform liquid-liquid extraction (LLE) for analysis. Limits of quantitation (LOQs), linearity and other method criteria were assessed, according to bioanalytical method validation guidelines. RESULTS: Reliable separation of 11-DHC and CORT was achieved using an ACE Excel 2 C18-AR (2.1 × 150 mm; 2 µm) fused core column at 25°C, with an acidified water/acetonitrile gradient over 10 min. Analytes were detected by multiple reaction monitoring after positive electrospray ionisation (m/z 345.1.1 â 121.2, m/z 347.1 â 121.1 for 11-DHC and CORT, respectively). The LOQs were 0.25 and 0.20 ng/mL for 11-DHC and CORT, respectively. CONCLUSIONS: This LC/MS method is suitable for the reliable analysis of 11-DHC and CORT following simple LLE of murine plasma, bringing preclinical analysis in line with recommendations for clinical endocrinology and biochemistry.
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Cromatografía Liquida/métodos , Corticosterona/análogos & derivados , Espectrometría de Masas en Tándem/métodos , Animales , Corticosterona/sangre , Corticosterona/química , Corticosterona/aislamiento & purificación , Límite de Detección , Modelos Lineales , Extracción Líquido-Líquido , Masculino , Ratones , Ratones Endogámicos C57BL , Reproducibilidad de los ResultadosRESUMEN
Insufficient alveolar gas exchange capacity is a major contributor to lung disease. During lung development, a population of distal epithelial progenitors first produce bronchiolar-fated and subsequently alveolar-fated progeny. The mechanisms controlling this bronchiolar-to-alveolar developmental transition remain largely unknown. We developed a novel grafting assay to test if lung epithelial progenitors are intrinsically programmed or if alveolar cell identity is determined by environmental factors. These experiments revealed that embryonic lung epithelial identity is extrinsically determined. We show that both glucocorticoid and STAT3 signalling can control the timing of alveolar initiation, but that neither pathway is absolutely required for alveolar fate specification; rather, glucocorticoid receptor and STAT3 work in parallel to promote alveolar differentiation. Thus, developmental acquisition of lung alveolar fate is a robust process controlled by at least two independent extrinsic signalling inputs. Further elucidation of these pathways might provide therapeutic opportunities for restoring alveolar capacity.
Asunto(s)
Células Epiteliales/citología , Células Epiteliales/metabolismo , Glucocorticoides/metabolismo , Pulmón/citología , Pulmón/metabolismo , Células Madre/citología , Células Madre/metabolismo , Adenoviridae/genética , Células Epiteliales Alveolares/citología , Células Epiteliales Alveolares/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Células Cultivadas , Glucocorticoides/antagonistas & inhibidores , Humanos , Ratones , Mifepristona/farmacología , Alveolos Pulmonares/citología , Alveolos Pulmonares/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genéticaRESUMEN
A hallmark of chronic liver injury is fibrosis, with accumulation of extracellular matrix orchestrated by activated hepatic stellate cells (HSCs). Glucocorticoids limit HSC activation in vitro, and tissue glucocorticoid levels are amplified by 11beta-hydroxysteroid dehydrogenase-1 (11ßHSD1). Although 11ßHSD1 inhibitors have been developed for type 2 diabetes mellitus and improve diet-induced fatty liver in various mouse models, effects on the progression and/or resolution of liver injury and consequent fibrosis have not been characterized. We have used the reversible carbon tetrachloride-induced model of hepatocyte injury and liver fibrosis to show that in two models of genetic 11ßHSD1 deficiency (global, Hsd11b1-/- , and hepatic myofibroblast-specific, Hsd11b1fl/fl /Pdgfrb-cre) 11ßHSD1 pharmacological inhibition in vivo exacerbates hepatic myofibroblast activation and liver fibrosis. In contrast, liver injury and fibrosis in hepatocyte-specific Hsd11b1fl/fl /albumin-cre mice did not differ from that of controls, ruling out 11ßHSD1 deficiency in hepatocytes as the cause of the increased fibrosis. In primary HSC culture, glucocorticoids inhibited expression of the key profibrotic genes Acta2 and Col1α1, an effect attenuated by the 11ßHSD1 inhibitor [4-(2-chlorophenyl-4-fluoro-1-piperidinyl][5-(1H-pyrazol-4-yl)-3-thienyl]-methanone. HSCs from Hsd11b1-/- and Hsd11b1fl/fl /Pdgfrb-cre mice expressed higher levels of Acta2 and Col1α1 and were correspondingly more potently activated. In vivo [4-(2-chlorophenyl-4-fluoro-1-piperidinyl][5-(1H-pyrazol-4-yl)-3-thienyl]-methanone administration prior to chemical injury recapitulated findings in Hsd11b1-/- mice, including greater fibrosis. CONCLUSION: 11ßHSD1 deficiency enhances myofibroblast activation and promotes initial fibrosis following chemical liver injury; hence, the effects of 11ßHSD1 inhibitors on liver injury and repair are likely to be context-dependent and deserve careful scrutiny as these compounds are developed for chronic diseases including metabolic syndrome and dementia. (Hepatology 2018;67:2167-2181).
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasas/antagonistas & inhibidores , 11-beta-Hidroxiesteroide Deshidrogenasas/deficiencia , Cirrosis Hepática/etiología , Miofibroblastos/fisiología , Animales , Modelos Animales de Enfermedad , Hepatocitos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Fetoplacental glucocorticoid overexposure is a significant mechanism underlying fetal growth restriction and the programming of adverse health outcomes in the adult. Placental glucocorticoid inactivation by 11ß-hydroxysteroid dehydrogenase type 2 (11ß-HSD2) plays a key role. We previously discovered that Hsd11b2(-/-) mice, lacking 11ß-HSD2, show marked underdevelopment of the placental vasculature. We now explore the consequences for fetal cardiovascular development and whether this is reversible. We studied Hsd11b2(+/+), Hsd11b2(+/-), and Hsd11b2(-/-) littermates from heterozygous (Hsd11b(+/-)) matings at embryonic day (E)14.5 and E17.5, where all three genotypes were present to control for maternal effects. Using high-resolution ultrasound, we found that umbilical vein blood velocity in Hsd11b2(-/-) fetuses did not undergo the normal gestational increase seen in Hsd11b2(+/+) littermates. Similarly, the resistance index in the umbilical artery did not show the normal gestational decline. Surprisingly, given that 11ß-HSD2 absence is predicted to initiate early maturation, the E/A wave ratio was reduced at E17.5 in Hsd11b2(-/-) fetuses, suggesting impaired cardiac function. Pravastatin administration from E6.5, which increases placental vascular endothelial growth factor A and, thus, vascularization, increased placental fetal capillary volume, ameliorated the aberrant umbilical cord velocity, normalized fetal weight, and improved the cardiac function of Hsd11b2(-/-) fetuses. This improved cardiac function occurred despite persisting indications of increased glucocorticoid exposure in the Hsd11b2(-/-) fetal heart. Thus, the pravastatin-induced enhancement of fetal capillaries within the placenta and the resultant hemodynamic changes correspond with restored fetal cardiac function. Statins may represent a useful therapeutic approach to intrauterine growth retardation due to placental vascular hypofunction.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/fisiología , Retardo del Crecimiento Fetal/prevención & control , Glucocorticoides/metabolismo , Cardiopatías/prevención & control , Enfermedades Placentarias/prevención & control , Pravastatina/farmacología , Animales , Anticolesterolemiantes/farmacología , Femenino , Retardo del Crecimiento Fetal/metabolismo , Retardo del Crecimiento Fetal/patología , Cardiopatías/metabolismo , Cardiopatías/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Enfermedades Placentarias/metabolismo , Enfermedades Placentarias/patología , Embarazo , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Chronically elevated glucocorticoid levels impair cognition and are pro-inflammatory in the brain. Deficiency or inhibition of 11ß-hydroxysteroid dehydrogenase type-1 (11ß-HSD1), which converts inactive into active glucocorticoids, protects against glucocorticoid-associated chronic stress- or age-related cognitive impairment. Here, we hypothesised that 11ß-HSD1 deficiency attenuates the brain cytokine response to inflammation. Because inflammation is associated with altered energy metabolism, we also examined the effects of 11ß-HSD1 deficiency upon hippocampal energy metabolism. Inflammation was induced in 11ß-HSD1 deficient (Hsd11b1Del/Del) and C57BL/6 control mice by intraperitoneal injection of lipopolysaccharide (LPS). LPS reduced circulating neutrophil and monocyte numbers and increased plasma corticosterone levels equally in C57BL/6 and Hsd11b1Del/Del mice, suggesting a similar peripheral inflammatory response. However, the induction of pro-inflammatory cytokine mRNAs in the hippocampus was attenuated in Hsd11b1Del/Del mice. Principal component analysis of mRNA expression revealed a distinct metabolic response to LPS in hippocampus of Hsd11b1Del/Del mice. Expression of Pfkfb3 and Ldha, key contributors to the Warburg effect, showed greater induction in Hsd11b1Del/Del mice. Consistent with increased glycolytic flux, levels of 3-phosphoglyceraldehyde and dihydroxyacetone phosphate were reduced in hippocampus of LPS injected Hsd11b1Del/Del mice. Expression of Sdha and Sdhb, encoding subunits of succinate dehydrogenase/complex II that determines mitochondrial reserve respiratory capacity, was induced specifically in hippocampus of LPS injected Hsd11b1Del/Del mice, together with increased levels of its product, fumarate. These data suggest 11ß-HSD1 deficiency attenuates the hippocampal pro-inflammatory response to LPS, associated with increased capacity for aerobic glycolysis and mitochondrial ATP generation. This may provide better metabolic support and be neuroprotective during systemic inflammation or aging.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , Metabolismo Energético/fisiología , Hipocampo/metabolismo , Inflamación/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Corticosterona/sangre , Hipocampo/efectos de los fármacos , Conducta de Enfermedad/efectos de los fármacos , Conducta de Enfermedad/fisiología , Inflamación/metabolismo , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/metabolismo , Monocitos/metabolismo , Neutrófilos/metabolismoRESUMEN
The glucocorticoid receptor (GR) is a member of the nuclear receptor superfamily, which controls programs regulating cell proliferation, differentiation, and apoptosis. We have identified an unexpected role for GR in mitosis. We discovered that specifically modified GR species accumulate at the mitotic spindle during mitosis in a distribution that overlaps with Aurora kinases. We found that Aurora A was required to mediate mitosis-driven GR phosphorylation, but not recruitment of GR to the spindle. GR was necessary for mitotic progression, with increased time to complete mitosis, frequency of mitotic aberrations, and death in mitosis observed following GR knockdown. Complementation studies revealed an essential role for the GR ligand-binding domain, but no clear requirement for ligand binding in regulating chromosome segregation. The GR N-terminal domain, and specifically phosphosites S203 and S211, were not required. Reduced GR expression results in a cell cycle phenotype, with isolated cells from mouse and human subjects showing changes in chromosome content over prolonged passage. Furthermore, GR haploinsufficient mice have an increased incidence of tumor formation, and, strikingly, these tumors are further depleted for GR, implying additional GR loss as a consequence of cell transformation. We identified reduced GR expression in a panel of human liver, lung, prostate, colon, and breast cancers. We therefore reveal an unexpected role for the GR in promoting accurate chromosome segregation during mitosis, which is causally linked to tumorigenesis, making GR an authentic tumor suppressor gene.
Asunto(s)
Transformación Celular Neoplásica/metabolismo , Segregación Cromosómica , Regulación Neoplásica de la Expresión Génica , Neoplasias/metabolismo , Receptores de Glucocorticoides/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Humanos , Ratones , Ratones Mutantes , Mitosis/genética , Neoplasias/genética , Neoplasias/patología , Estructura Terciaria de Proteína , Receptores de Glucocorticoides/genética , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor/genéticaRESUMEN
Genome-wide association studies have consistently implicated the interleukin-15 (IL-15) gene in acute lymphoblastic leukemia (ALL) biology, including associations with disease susceptibility, and increased risk of central nervous system (CNS) involvement. However, whether pre-B ALL blasts directly respond to IL-15 is unknown. Here, we show that most pre-B ALL primary samples and cell lines express IL-15 and components of its receptor and that primary pre-B ALL cells show increased growth in culture in response to IL-15. Investigation of mechanisms of action using IL-15-responsive SD-1 cells shows this growth advantage is maximal under low-serum conditions, mimicking those found in cerebrospinal fluid. IL-15 also upregulates PSGL-1 and CXCR3, molecules associated with CNS trafficking. Investigation of downstream signaling pathways indicates that IL-15 induces signal transducer and activator of transcription 5 (STAT5), extracellular signal-regulated kinase (ERK) 1/2, and to a lesser extent phosphatidylinositol 3-kinase (PI3K) and nuclear factor κB (NF-κB) phosphorylation. The IL-15-mediated growth advantage is abolished by mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK), PI3K, and NF-κB inhibitors but preserved in the presence of STAT5 inhibition. Together, these observations provide a mechanistic link between increased levels of IL-15 expression and leukemogenesis, high-risk disease, and CNS relapse and suggest potential therapeutic targets.
Asunto(s)
Sistema Nervioso Central/inmunología , Interleucina-15/inmunología , Proteínas Quinasas Activadas por Mitógenos/inmunología , FN-kappa B/inmunología , Fosfatidilinositol 3-Quinasas/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Sistema Nervioso Central/metabolismo , Sistema Nervioso Central/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Interleucina-15/genética , Glicoproteínas de Membrana/genética , Ratones , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , FN-kappa B/antagonistas & inhibidores , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidor 1 de Activador Plasminogénico/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Receptores CXCR3/genética , Factor de Transcripción STAT5/antagonistas & inhibidores , Factor de Transcripción STAT5/inmunología , Transducción de Señal , Regulación hacia ArribaRESUMEN
Glucocorticoids are vital for the structural and functional maturation of foetal organs, yet excessive foetal exposure is detrimental to adult cardiovascular health. To elucidate the role of glucocorticoid signalling in late-gestation cardiovascular maturation, we have generated mice with conditional disruption of glucocorticoid receptor (GR) in cardiomyocytes and vascular smooth muscle cells using smooth muscle protein 22-driven Cre recombinase (SMGRKO mice) and compared them with mice with global deficiency in GR (GR(-/-)). Echocardiography shows impaired heart function in both SMGRKO and GR(-/-) mice at embryonic day (E)17.5, associated with generalized oedema. Cardiac ultrastructure is markedly disrupted in both SMGRKO and GR(-/-) mice at E17.5, with short, disorganized myofibrils and cardiomyocytes that fail to align in the compact myocardium. Failure to induce critical genes involved in contractile function, calcium handling and energy metabolism underpins this common phenotype. However, although hearts of GR(-/-) mice are smaller, with 22% reduced ventricular volume at E17.5, SMGRKO hearts are normally sized. Moreover, while levels of mRNA encoding atrial natriuretic peptide are reduced in E17.5 GR(-/-) hearts, they are normal in foetal SMGRKO hearts. These data demonstrate that structural, functional and biochemical maturation of the foetal heart is dependent on glucocorticoid signalling within cardiomyocytes and vascular smooth muscle, though some aspects of heart maturation (size, ANP expression) are independent of GR at these key sites.
Asunto(s)
Corazón Fetal/crecimiento & desarrollo , Glucocorticoides/metabolismo , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Transducción de Señal , Animales , Corticosterona/sangre , Corticosterona/fisiología , Corazón Fetal/fisiología , Corazón/embriología , Corazón/fisiología , Ratones , Ratones Transgénicos , Músculo Liso Vascular/embriología , Músculo Liso Vascular/metabolismo , Contracción Miocárdica , Miocardio/ultraestructura , Miocitos Cardíacos/citología , Miocitos Cardíacos/metabolismo , Miofibrillas/ultraestructuraRESUMEN
The 5-hydroxytryptamine2C (5-HT)2C receptor is widely implicated in the aetiology of affective and eating disorders as well as regulation of the hypothalamo-pituitary-adrenal axis. Signalling through this receptor is regulated by A-to-I RNA editing, affecting three amino acids in the protein sequence, with unedited transcripts encoding a receptor (INI) that, in vitro, is hyperactive compared with edited isoforms. Targeted alteration (knock-in) of the Htr2c gene to generate 'INI' mice with no alternate splicing, solely expressing the full-length unedited isoform, did not produce an overt metabolic phenotype or altered anxiety behaviour, but did display reduced depressive-like and fear-associated behaviours. INI mice exhibited a hyperactive hypothalamo-pituitary-adrenal axis, with increased nadir plasma corticosterone and corticotrophin-releasing hormone expression in the hypothalamus but responded normally to chronic stress and showed normal circadian activity and activity in a novel environment. The circadian patterns of 5-HT2C receptor mRNA and mbii52, a snoRNA known to regulate RNA editing and RNA splicing of 5-HT2C receptor pre-mRNA, were altered in INI mice compared with wild-type control mice. Moreover, levels of 5-HT1A receptor mRNA were increased in the hippocampus of INI mice. These gene expression changes may underpin the neuroendocrine and behavioural changes observed in INI mice. However, the phenotype of INI mice was not consistent with a globally hyperactive INI receptor encoded by the unedited transcript in the absence of alternate splicing. Hence, the in vivo outcome of RNA editing may be neuronal cell type specific.
Asunto(s)
Afecto/fisiología , Hormona Liberadora de Corticotropina/metabolismo , Sistema Hipotálamo-Hipofisario/metabolismo , Sistema Hipófiso-Suprarrenal/metabolismo , Receptor de Serotonina 5-HT2C/metabolismo , Empalme Alternativo , Animales , Ritmo Circadiano/fisiología , Corticosterona/sangre , Depresión/genética , Depresión/metabolismo , Miedo/fisiología , Técnicas de Sustitución del Gen , Masculino , Memoria/fisiología , Ratones Endogámicos C57BL , Ratones Transgénicos , Actividad Motora/fisiología , Edición de ARN , ARN Mensajero/metabolismo , ARN Nucleolar Pequeño/metabolismo , Receptor de Serotonina 5-HT1A/metabolismo , Receptor de Serotonina 5-HT2C/genética , Estrés Psicológico/genética , Estrés Psicológico/metabolismoRESUMEN
11ß-Hydroxysteroid dehydrogenase type-1 (11ß-HSD1) converts inert cortisone into active cortisol, amplifying intracellular glucocorticoid action. 11ß-HSD1 deficiency improves cardiovascular risk factors in obesity but exacerbates acute inflammation. To determine the effects of 11ß-HSD1 deficiency on atherosclerosis and its inflammation, atherosclerosis-prone apolipoprotein E-knockout (ApoE-KO) mice were treated with a selective 11ß-HSD1 inhibitor or crossed with 11ß-HSD1-KO mice to generate double knockouts (DKOs) and challenged with an atherogenic Western diet. 11ß-HSD1 inhibition or deficiency attenuated atherosclerosis (74-76%) without deleterious effects on plaque structure. This occurred without affecting plasma lipids or glucose, suggesting independence from classical metabolic risk factors. KO plaques were not more inflamed and indeed had 36% less T-cell infiltration, associated with 38% reduced circulating monocyte chemoattractant protein-1 (MCP-1) and 36% lower lesional vascular cell adhesion molecule-1 (VCAM-1). Bone marrow (BM) cells are key to the atheroprotection, since transplantation of DKO BM to irradiated ApoE-KO mice reduced atherosclerosis by 51%. 11ß-HSD1-null macrophages show 76% enhanced cholesterol ester export. Thus, 11ß-HSD1 deficiency reduces atherosclerosis without exaggerated lesional inflammation independent of metabolic risk factors. Selective 11ß-HSD1 inhibitors promise novel antiatherosclerosis effects over and above their benefits for metabolic risk factors via effects on BM cells, plausibly macrophages.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/deficiencia , Aterosclerosis/metabolismo , Médula Ósea/metabolismo , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/antagonistas & inhibidores , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Aterosclerosis/genética , Médula Ósea/efectos de los fármacos , Glucocorticoides/metabolismo , Ratones , Ratones Noqueados , Factores de Riesgo , Molécula 1 de Adhesión Celular Vascular/metabolismoAsunto(s)
Glucocorticoides/metabolismo , Síndrome Mucocutáneo Linfonodular/metabolismo , Transducción de Señal , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Niño , Femenino , Humanos , Japón , Masculino , ARN Mensajero/metabolismo , Receptores de Glucocorticoides/genéticaRESUMEN
Bone marrow adipose tissue (BMAT) comprises >10% of total adipose mass in healthy humans. It increases in diverse conditions, including ageing, obesity, osteoporosis, glucocorticoid therapy, and notably, during caloric restriction (CR). BMAT potentially influences skeletal, metabolic, and immune functions, but the mechanisms of BMAT expansion remain poorly understood. Our hypothesis is that, during CR, excessive glucocorticoid activity drives BMAT expansion. The enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) amplifies glucocorticoid activity by catalysing intracellular regeneration of active glucocorticoids from inert 11-keto forms. Mice lacking 11ß-HSD1 resist metabolic dysregulation and bone loss during exogenous glucocorticoid excess; thus, we hypothesised that 11ß-HSD1 knockout mice would also resist excessive glucocorticoid action during CR, thereby restrining BMAT expansion and bone loss. To test this, we first confirmed that 11ß-HSD1 is expressed in mouse and human bone marrow. We then investigated the effects of CR in male and female control and 11ß-HSD1 knockout mice from 9 to 15 weeks of age. CR increased Hsd11b1 mRNA in adipose tissue and bone marrow. Deletion of Hsd11b1 did not alter bone or BMAT characteristics in mice fed a control diet and had little effect on tibial bone microarchitecture during CR. Notably, Hsd11b1 deletion attenuated the CR-induced increases in BMAT and prevented increases in bone marrow corticosterone in males but not females. This was not associated with suppression of glucocorticoid target genes in bone marrow. Instead, knockout males had increased progesterone in plasma and bone marrow. Together, our findings show that knockout of 11ß-HSD1 prevents CR-induced BMAT expansion in a sex-specific manner and highlights progesterone as a potential new regulator of bone marrow adiposity.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1 , Adiposidad , Médula Ósea , Restricción Calórica , Ratones Noqueados , Animales , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Femenino , Masculino , Adiposidad/genética , Médula Ósea/metabolismo , Ratones , Humanos , Tejido Adiposo/metabolismo , Ratones Endogámicos C57BL , Glucocorticoides/metabolismo , Factores SexualesRESUMEN
Atherosclerosis is a chronic inflammatory disease in which initial vascular damage leads to extensive macrophage and lymphocyte infiltration. Although acutely glucocorticoids suppress inflammation, chronic glucocorticoid excess worsens atherosclerosis, possibly by exacerbating systemic cardiovascular risk factors. However, glucocorticoid action within the lesion may reduce neointimal proliferation and inflammation. Glucocorticoid levels within cells do not necessarily reflect circulating levels due to pre-receptor metabolism by 11ß-hydroxysteroid dehydrogenases (11ß-HSDs). 11ß-HSD2 converts active glucocorticoids into inert 11-keto forms. 11ß-HSD1 catalyses the reverse reaction, regenerating active glucocorticoids. 11ß-HSD2-deficiency/inhibition causes hypertension, whereas deficiency/inhibition of 11ß-HSD1 generates a cardioprotective lipid profile and improves glycemic control. Importantly, 11ß-HSD1-deficiency/inhibition is atheroprotective, whereas 11ß-HSD2-deficiency accelerates atherosclerosis. These effects are largely independent of systemic risk factors, reflecting modulation of glucocorticoid action and inflammation within the vasculature. Here, we consider whether evidence linking the 11ß-HSDs to vascular inflammation suggests these isozymes are potential therapeutic targets in vascular injury and atherosclerosis.
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11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/fisiología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/fisiología , Aterosclerosis/inmunología , Glucocorticoides/inmunología , Vasculitis/inmunología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/antagonistas & inhibidores , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/inmunología , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/inmunología , Aterosclerosis/complicaciones , Aterosclerosis/enzimología , Glucocorticoides/metabolismo , Humanos , Neointima/inmunología , Vasculitis/complicaciones , Vasculitis/enzimologíaRESUMEN
Increased dietary fat intake is associated with obesity, insulin resistance, and metabolic disease. In transgenic mice, adipose tissue-specific overexpression of the glucocorticoid-amplifying enzyme 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) exacerbates high-fat (HF) diet-induced visceral obesity and diabetes, whereas 11ß-HSD1 gene knockout ameliorates this, favoring accumulation of fat in nonvisceral depots. Paradoxically, in normal mice HF diet-induced obesity (DIO) is associated with marked downregulation of adipose tissue 11ß-HSD1 levels. To identify the specific dietary fats that regulate adipose 11ß-HSD1 and thereby impact upon metabolic disease, we either fed mice diets enriched (45% calories as fat) in saturated (stearate), monounsaturated (oleate), or polyunsaturated (safflower oil) fats ad libitum or we pair fed them a low-fat (11%) control diet for 4 wk. Adipose and liver mass and glucocorticoid receptor and 11ß-HSD1 mRNA and activity levels were determined. Stearate caused weight loss and hypoinsulinemia, partly due to malabsorption, and this markedly increased plasma corticosterone levels and adipose 11ß-HSD1 activity. Oleate induced pronounced weight gain and hyperinsulinemia in association with markedly low plasma corticosterone and adipose 11ß-HSD1 activity. Weight gain and hyperinsulinemia was less pronounced with safflower compared with oleate despite comparable suppression of plasma corticosterone and adipose 11ß-HSD1. However, with pair feeding, safflower caused a selective reduction in visceral fat mass and relative insulin sensitization without affecting plasma corticosterone or adipose 11ß-HSD1. The dynamic depot-selective relationship between adipose 11ß-HSD1 and fat mass strongly implicates a dominant physiological role for local tissue glucocorticoid reactivation in fat mobilization.
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11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/biosíntesis , Tejido Adiposo/enzimología , Tejido Adiposo/fisiología , Composición Corporal/fisiología , Dieta , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , Adiposidad , Animales , Corticosterona/metabolismo , Ingestión de Alimentos/efectos de los fármacos , Ácidos Grasos/farmacología , Ácidos Grasos Monoinsaturados/farmacología , Ácidos Grasos Insaturados/farmacología , Heces/química , Expresión Génica/efectos de los fármacos , Homeostasis/efectos de los fármacos , Homeostasis/fisiología , Resistencia a la Insulina/fisiología , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Ratones , Ratones Endogámicos C57BL , ARN/biosíntesis , ARN/genética , Receptores de Glucocorticoides/biosíntesis , Receptores de Glucocorticoides/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Aumento de Peso/efectos de los fármacosRESUMEN
BACKGROUND AND PURPOSE: 11ß-Hydroxysteroid dehydrogenase 1 (11ß-HSD1) regulates tissue-specific glucocorticoid metabolism and its impaired expression and activity are associated with major diseases. Pharmacological inhibition of 11ß-HSD1 is considered a promising therapeutic strategy. This study investigated whether alternative 7-oxo bile acid substrates of 11ß-HSD1 or the ratios to their 7-hydroxy products can serve as biomarkers for decreased enzymatic activity. EXPERIMENTAL APPROACH: Bile acid profiles were measured by ultra-HPLC tandem-MS in plasma and liver tissue samples of four different mouse models with decreased 11ß-HSD1 activity: global (11KO) and liver-specific 11ß-HSD1 knockout mice (11LKO), mice lacking hexose-6-phosphate dehydrogenase (H6pdKO) that provides cofactor NADPH for 11ß-HSD1 and mice treated with the pharmacological inhibitor carbenoxolone. Additionally, 11ß-HSD1 expression and activity were assessed in H6pdKO- and carbenoxolone-treated mice. KEY RESULTS: The enzyme product to substrate ratios were more reliable markers of 11ß-HSD1 activity than absolute levels due to large inter-individual variations in bile acid concentrations. The ratio of the 7ß-hydroxylated ursodeoxycholyltaurine (UDC-Tau) to 7-oxolithocholyltaurine (7oxoLC-Tau) was diminished in plasma and liver tissue of all four mouse models and decreased in H6pdKO- and carbenoxolone-treated mice with moderately reduced 11ß-HSD1 activity. The persistence of 11ß-HSD1 oxoreduction activity in the face of H6PD loss indicates the existence of an alternative NADPH source in the endoplasmic reticulum. CONCLUSIONS AND IMPLICATIONS: The plasma UDC-Tau/7oxo-LC-Tau ratio detects decreased 11ß-HSD1 oxoreduction activity in different mouse models. This ratio may be a useful biomarker of decreased 11ß-HSD1 activity in pathophysiological situations or upon pharmacological inhibition. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.
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11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1 , Glucocorticoides , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/genética , Animales , Ácidos y Sales Biliares , Biomarcadores , Ratones , Ratones NoqueadosRESUMEN
Coronavirus disease (COVID-19) is caused by a new strain of coronavirus, the severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2. At the time of writing, SARS-CoV-2 has infected over 5 million people worldwide. A key step in understanding the pathobiology of the SARS-CoV-2 was the identification of -converting enzyme 2 (ACE2) as the receptor for SARS-CoV-2 to gain entry into host cells. ACE2 is an established component of the 'protective arm' of the renin-angiotensin-aldosterone-system (RAAS) that opposes ACE/angiotensin II (ANG II) pressor and tissue remodelling actions. Identification of ACE2 as the entry point for SARS-CoV-2 into cells quickly focused attention on the use of ACE inhibitors (ACEi), angiotensin receptor blockers (ARB) and mineralocorticoid receptor antagonists (MRA) in patients with hypertension and cardiovascular disease given that these pharmacological agents upregulate ACE2 expression in target cells. ACE2 is cleaved from the cells by metalloproteases ADAM10 and ADAM17. Steroid hormone receptors regulate multiple components of the RAAS and may contribute to the observed variation in the incidence of severe COVID-19 between men and women, and in patients with pre-existing endocrine-related disease. Moreover, glucocorticoids play a critical role in the acute and chronic management of inflammatory disease, independent of any effect on RAAS activity. Dexamethasone, a synthetic glucocorticoid, has emerged as a life-saving treatment in severe COVID-19. This review will examine the endocrine mechanisms that control ACE2 and discusses the impact of therapies targeting the RAAS, glucocorticoid and other endocrine systems for their relevance to the impact of SARS-CoV-2 infection and the treatment and recovery from COVID-19-related critical illness.