Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
J Autism Dev Disord ; 53(10): 3835-3846, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35925431

RESUMEN

Law enforcement officers are the primary individuals called and who respond to situations of heightened concern. They make split-second observations and decisions based on how best to react to given safety situations and those involved. Characteristics of autism spectrum disorders (ASD), if not properly understood and reacted to, may quickly escalate a law enforcement officer call in a negative way, making autism training for law enforcement officers imperative. To ascertain what is known about autism training for law enforcement officers, a scoping review was conducted. Five studies met final inclusion criteria. The trainees, context and development of the training, evaluation procedures, and training outcomes are synthesized to provide guidance for future training implementation teams. Areas for future research are presented.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Humanos , Policia/educación , Trastorno del Espectro Autista/terapia
2.
Genome Biol ; 23(1): 2, 2022 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-34980216

RESUMEN

BACKGROUND: Reproducible detection of inherited variants with whole genome sequencing (WGS) is vital for the implementation of precision medicine and is a complicated process in which each step affects variant call quality. Systematically assessing reproducibility of inherited variants with WGS and impact of each step in the process is needed for understanding and improving quality of inherited variants from WGS. RESULTS: To dissect the impact of factors involved in detection of inherited variants with WGS, we sequence triplicates of eight DNA samples representing two populations on three short-read sequencing platforms using three library kits in six labs and call variants with 56 combinations of aligners and callers. We find that bioinformatics pipelines (callers and aligners) have a larger impact on variant reproducibility than WGS platform or library preparation. Single-nucleotide variants (SNVs), particularly outside difficult-to-map regions, are more reproducible than small insertions and deletions (indels), which are least reproducible when > 5 bp. Increasing sequencing coverage improves indel reproducibility but has limited impact on SNVs above 30×. CONCLUSIONS: Our findings highlight sources of variability in variant detection and the need for improvement of bioinformatics pipelines in the era of precision medicine with WGS.


Asunto(s)
Genoma Humano , Polimorfismo de Nucleótido Simple , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación INDEL , Reproducibilidad de los Resultados , Secuenciación Completa del Genoma
4.
Artículo en Inglés | MEDLINE | ID: mdl-29734692

RESUMEN

The Inverse Care Law is principally concerned with the effect of market forces on health care which create inequities in access to health services through privileging individuals who possess the forms of social capital that are valued within health care settings. The fields of disaster risk reduction need to consider the ways in which inequities, driven by economic and social policy as well as institutional decision-making, create vulnerabilities prior to a disaster, which are then magnified post disaster through entrenched structural differences in access to resources. Drawing on key principles within the Inverse Care Law, the Inverse Response Law refers to the idea that people in lower socio-economic groups are more likely to be impacted and to experience disparities in service provision during the disaster response and recovery phase. In a market model of recovery, vulnerable groups struggle to compete for necessary services creating inequities in adaptive capacity as well as in social and wellbeing outcomes over time. Both the Inverse Care Law and the Inverse Response Law focus on the structural organisation of services at a macro level. In this article, the Inverse Care Law is outlined, its application to medical treatment following disasters considered and an explanation of the Inverse Response Law provided. Case studies from recent disasters, in London, New Zealand, Puerto Rico and Mexico City are examined in order to illustrate themes at work relating to the Inverse Response Law.


Asunto(s)
Planificación en Desastres/organización & administración , Desastres , Accesibilidad a los Servicios de Salud/organización & administración , Salud Pública , Planificación en Desastres/legislación & jurisprudencia , Eficiencia Organizacional , Accesibilidad a los Servicios de Salud/legislación & jurisprudencia , Necesidades y Demandas de Servicios de Salud , Disparidades en el Estado de Salud , Humanos , Poblaciones Vulnerables
5.
Health Soc Care Community ; 25(5): 1601-1606, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-26956945

RESUMEN

Many older people in Britain spend Christmas day alone. The Christmas period may be especially difficult for older people who are socially isolated, living with dementia or who have physical impairments, and may feel particularly marginalised at this time of year. This paper draws on evaluative research findings from a community Christmas event held in December 2014 at the University of Salford for older people and their carers who would be on their own on Christmas day. A multi-method approach was employed, seven guests took part in semi-structured interviews to explore their experiences and perceptions of the event, seven staff and student volunteers participated in a group interview to explore and discuss their participation in the event. Data collection took place during April and May 2015. Interview transcripts were subjected to thematic analysis. Three overarching themes were identified from the interviews: 'reasons for participants attending the event', 'a different Christmas day: the impact on guests and volunteers', and 'learning, planning and moving forwards'. The findings illustrate that a range of people participated in the Christmas day event for a variety of reasons. The event itself had a positive impact, including the shared experience of social belonging, for all involved. There are tangible longer term benefits as a result of the event, such as ongoing contact between participants and the development of supportive networks in the local community.


Asunto(s)
Cuidadores/estadística & datos numéricos , Vacaciones y Feriados , Soledad/psicología , Apoyo Social , Voluntarios/estadística & datos numéricos , Anciano , Femenino , Humanos , Masculino , Reino Unido
7.
Artículo en Inglés | MEDLINE | ID: mdl-27983666

RESUMEN

The Sendai Framework for Disaster Risk Reduction (2015) is a global strategy for addressing disaster risk and resilience that has been ratified by member countries of the United Nations. Its guiding principles emphasise building resilience through inter-sectoral collaboration, as well as partnerships that facilitate community empowerment and address underlying risk factors. Both public health and the emergency management sector face similar challenges related to developing and implementing strategies that involve structural change, facilitating community resilience and addressing individual risk factors. Familiarity with public health principles enables an understanding of the holistic approach to risk reduction that is outlined within the Sendai Framework. We present seven concepts that resonate with contemporary public health practice, namely: the social determinants of health; inequality and inequity; the inverse care law; community-based and community development approaches; hard to reach communities and services; the prevention paradox; and the inverse prevention law. These ideas from public health provide a useful conceptual base for the "new" agenda in disaster risk management that underpins the 2015 Sendai Framework. The relevance of these ideas to disaster risk management and research is illustrated through drawing on the Sendai Framework, disaster literature and exemplars from the 2010-2011 earthquakes in Canterbury, New Zealand.


Asunto(s)
Planificación en Desastres/organización & administración , Salud Pública , Características de la Residencia , Disparidades en el Estado de Salud , Disparidades en Atención de Salud , Humanos , Práctica de Salud Pública , Factores de Riesgo , Conducta de Reducción del Riesgo , Determinantes Sociales de la Salud , Naciones Unidas , Poblaciones Vulnerables
8.
Biol Reprod ; 93(3): 69, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26203175

RESUMEN

Polycystic ovary syndrome (PCOS) pathophysiology is poorly understood, due partly to lack of PCOS animal models fully recapitulating this complex disorder. Recently, a PCOS rat model using letrozole (LET), a nonsteroidal aromatase inhibitor, mimicked multiple PCOS phenotypes, including metabolic features absent in other models. Given the advantages of using genetic and transgenic mouse models, we investigated whether LET produces a similar PCOS phenotype in mice. Pubertal female C57BL/6N mice were treated for 5 wk with LET, which resulted in increased serum testosterone and normal diestrus levels of estradiol, similar to the hyperandrogenemia and follicular phase estrogen levels of PCOS women. As in PCOS, ovaries from LET mice were larger, polycystic, and lacked corpora lutea versus controls. Most LET females were acyclic, and all were infertile. LET females displayed elevated serum LH levels and higher Lhb mRNA in the pituitary. In contrast, serum FSH and Fshb were significantly reduced in LET females, demonstrating differential effects on gonadotropins, as in PCOS. Within the ovary, LET females had higher Cyp17, Cyp19, and Fsh receptor mRNA expression. In the hypothalamus, LET females had higher kisspeptin receptor mRNA expression but lower progesterone receptor mRNA levels. LET females also gained more weight than controls, had increased abdominal adiposity and adipocyte size, elevated adipose inflammatory mRNA levels, and impaired glucose tolerance, mirroring the metabolic phenotype in PCOS women. This is the first report of a LET paradigm in mice that recapitulates both reproductive and metabolic PCOS phenotypes and will be useful to genetically probe the PCOS condition.


Asunto(s)
Inhibidores Enzimáticos/toxicidad , Nitrilos/toxicidad , Síndrome del Ovario Poliquístico/inducido químicamente , Síndrome del Ovario Poliquístico/patología , Reproducción/efectos de los fármacos , Triazoles/toxicidad , Animales , Cuerpo Lúteo/metabolismo , Diestro/metabolismo , Ciclo Estral/efectos de los fármacos , Femenino , Hiperandrogenismo/sangre , Hiperandrogenismo/inducido químicamente , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Kisspeptinas/biosíntesis , Kisspeptinas/genética , Letrozol , Ratones , Ratones Endogámicos C57BL , Fenotipo , Hipófisis/efectos de los fármacos , Hipófisis/metabolismo , Síndrome del Ovario Poliquístico/metabolismo , Embarazo , Testosterona/sangre
9.
Endocrinology ; 155(11): 4433-46, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25147978

RESUMEN

Hypothalamic GnRH is the master regulator of the neuroendocrine reproductive axis, and its secretion is regulated by many factors. Among these is kisspeptin (Kp), a potent trigger of GnRH secretion. Kp signals via the Kp receptor (KISS1R), a Gαq/11-coupled 7-transmembrane-spanning receptor. Until this study, it was understood that KISS1R mediates GnRH secretion via the Gαq/11-coupled pathway in an ERK1/2-dependent manner. We recently demonstrated that KISS1R also signals independently of Gαq/11 via ß-arrestin and that this pathway also mediates ERK1/2 activation. Because GnRH secretion is ERK1/2-dependent, we hypothesized that KISS1R regulates GnRH secretion via both the Gαq/11- and ß-arrestin-coupled pathways. To test this hypothesis, we measured LH secretion, a surrogate marker of GnRH secretion, in mice lacking either ß-arrestin-1 or ß-arrestin-2. Results revealed that Kp-dependent LH secretion was significantly diminished relative to wild-type mice (P < .001), thus supporting that ß-arrestin mediates Kp-induced GnRH secretion. Based on this, we hypothesized that Gαq/11-uncoupled KISS1R mutants, like L148S, will display Gαq/11-independent signaling. To test this hypothesis, L148S was expressed in HEK 293 cells. and results confirmed that, although strongly uncoupled from Gαq/11, L148S retained the ability to trigger significant Kp-dependent ERK1/2 phosphorylation (P < .05). Furthermore, using mouse embryonic fibroblasts lacking ß-arrestin-1 and -2, we demonstrated that L148S-mediated ERK1/2 phosphorylation is ß-arrestin-dependent. Overall, we conclude that KISS1R signals via Gαq/11 and ß-arrestin to regulate GnRH secretion. This novel and important finding could explain why patients bearing some types of Gαq/11-uncoupled KISS1R mutants display partial gonadotropic deficiency and even a reversal of the condition, idiopathic hypogonadotropic hypogonadism.


Asunto(s)
Arrestinas/fisiología , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/fisiología , Hormona Luteinizante/metabolismo , Receptores Acoplados a Proteínas G/fisiología , Animales , Arrestinas/genética , Buserelina/farmacología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Kisspeptina-1 , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , beta-Arrestina 1 , Arrestina beta 2 , beta-Arrestinas
10.
Endocrinology ; 155(10): 3909-19, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25057795

RESUMEN

Mutations in neurokinin B (NKB) and its receptor, NK3R, were identified in human patients with hypogonadotropic hypogonadism, a disorder characterized by lack of puberty and infertility. Further studies have suggested that NKB acts at the level of the hypothalamus to control GnRH neuron activity, either directly or indirectly. We recently reported that treatment with senktide, a NK3R agonist, induced GnRH secretion and expression of c-fos mRNA in GT1-7 cells. Here, we map the responsive region in the murine c-fos promoter to between -400 and -200 bp, identify the signal transducer and activator of transcription (STAT) (-345) and serum response element (-310) sites as required for induction, a modulatory role for the Ets site (-318), and show that induction is protein kinase C dependent. Using gel shift and Gal4 assays, we further show that phosphorylation of Elk-1 leads to binding to DNA in complex with serum response factor at serum response element and Ets sites within the c-fos promoter. Thus, we determine molecular mechanisms involved in NKB regulation of c-fos induction, which may play a role in modulation of GnRH neuron activation.


Asunto(s)
Hormona Liberadora de Gonadotropina/metabolismo , Neuroquinina B/fisiología , Neuronas/efectos de los fármacos , Proteína Quinasa C/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Factor de Respuesta Sérica/metabolismo , Transcripción Genética/fisiología , Proteína Elk-1 con Dominio ets/fisiología , Animales , Línea Celular Transformada , Ratones , Neuroquinina B/farmacología , Neuronas/metabolismo , Ratas , Transducción de Señal , Transcripción Genética/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos
11.
Mol Cell Endocrinol ; 381(1-2): 8-15, 2013 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-23880664

RESUMEN

Reproduction is integrated by interaction of neural and hormonal signals converging on hypothalamic neurons for controlling gonadotropin-releasing hormone (GnRH). Kisspeptin, the peptide product of the kiss1 gene and the endogenous agonist for the GRP54 receptor, plays a key role in the regulation of GnRH secretion. In the present study, we investigated the interaction between kisspeptin, estrogen and BMPs in the regulation of GnRH production by using mouse hypothalamic GT1-7 cells. Treatment with kisspeptin increased GnRH mRNA expression and GnRH protein production in a concentration-dependent manner. The expression levels of kiss1 and GPR54 were not changed by kisspeptin stimulation. Kisspeptin induction of GnRH was suppressed by co-treatment with BMPs, with BMP-4 action being the most potent for suppressing the kisspeptin effect. The expression of kisspeptin receptor, GPR54, was suppressed by BMPs, and this effect was reversed in the presence of kisspeptin. It was also revealed that BMP-induced Smad1/5/8 phosphorylation and Id-1 expression were suppressed and inhibitory Smad6/7 was induced by kisspeptin. In addition, estrogen induced GPR54 expression, while kisspeptin increased the expression levels of ERα and ERß, suggesting that the actions of estrogen and kisspeptin are mutually enhanced in GT1-7 cells. Moreover, kisspeptin stimulated MAPKs and AKT signaling, and ERK signaling was functionally involved in the kisspeptin-induced GnRH expression. BMP-4 was found to suppress kisspeptin-induced GnRH expression by reducing ERK signaling activity. Collectively, the results indicate that the axis of kisspeptin-induced GnRH production is bi-directionally controlled, being augmented by an interaction between ERα/ß and GPR54 signaling and suppressed by BMP-4 action in GT1-7 neuron cells.


Asunto(s)
Proteína Morfogenética Ósea 4/fisiología , Estrógenos/fisiología , Kisspeptinas/fisiología , Receptores LHRH/metabolismo , Animales , Línea Celular , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Expresión Génica , Hormona Liberadora de Gonadotropina/metabolismo , Hipocampo/citología , Humanos , Sistema de Señalización de MAP Quinasas , Ratones , Neuronas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Kisspeptina-1 , Receptores LHRH/genética
12.
Mol Endocrinol ; 27(3): 437-54, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23393128

RESUMEN

Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription.


Asunto(s)
Hormona Liberadora de Gonadotropina/genética , Hormona Liberadora de Gonadotropina/metabolismo , Neuroquinina B/metabolismo , Neuronas/metabolismo , Transcripción Genética , Animales , Emparejamiento Base/genética , Sitios de Unión , Línea Celular , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Ensamble y Desensamble de Cromatina/genética , Elementos de Facilitación Genéticos/genética , Humanos , Ratones , Neuronas/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Unión Proteica/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Ratas , Receptores de Neuroquinina-3/metabolismo , Eliminación de Secuencia/genética , Sustancia P/análogos & derivados , Sustancia P/farmacología , Factores de Tiempo , Factor de Transcripción AP-1/metabolismo , Transcripción Genética/efectos de los fármacos
13.
J Clin Invest ; 121(2): 604-12, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21245576

RESUMEN

In addition to its role in reproduction, estradiol-17ß is critical to the regulation of energy balance and body weight. Estrogen receptor α-null (Erα-/-) mutant mice develop an obese state characterized by decreased energy expenditure, decreased locomotion, increased adiposity, altered glucose homeostasis, and hyperleptinemia. Such features are reminiscent of the propensity of postmenopausal women to develop obesity and type 2 diabetes. The mechanisms by which ERα signaling maintains normal energy balance, however, have remained unclear. Here we used knockin mice that express mutant ERα that can only signal through the noncanonical pathway to assess the role of nonclassical ERα signaling in energy homeostasis. In these mice, we found that nonclassical ERα signaling restored metabolic parameters dysregulated in Erα-/- mutant mice to normal or near-normal values. The rescue of body weight and metabolic function by nonclassical ERα signaling was mediated by normalization of energy expenditure, including voluntary locomotor activity. These findings indicate that nonclassical ERα signaling mediates major effects of estradiol-17ß on energy balance, raising the possibility that selective ERα agonists may be developed to reduce the risks of obesity and metabolic disturbances in postmenopausal women.


Asunto(s)
Metabolismo Energético/fisiología , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Transducción de Señal/fisiología , Animales , Peso Corporal/genética , Ingestión de Alimentos , Femenino , Homeostasis , Humanos , Leptina/metabolismo , Ratones , Ratones Noqueados , Ratones Obesos , Actividad Motora , Obesidad/genética , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo
14.
Biol Reprod ; 81(5): 956-65, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19605792

RESUMEN

Aromatase (CYP19A1) catalyzes the conversion of C(19) steroids to estrogens. Aromatase and its product estradiol (E(2)) are crucial for the sexually dimorphic development of the fetal brain and the regulation of gonadotropin secretion and sexual interest in adults. The regulation of aromatase expression in the brain is not well understood. The aromatase (Cyp19a1) gene is selectively expressed in distinct neurons of the hypothalamus through a distal brain-specific promoter I.f located approximately 36 kb upstream of the coding region. Here, we investigated a short feedback effect of E(2) on aromatase mRNA expression and enzyme activity using estrogen receptor alpha (ESR1; also known as ER alpha)-positive or ESR1-negative mouse embryonic hypothalamic neuronal cell lines that express aromatase via promoter I.f. Estradiol regulated aromatase mRNA expression and enzyme activity in a time- and dose-dependent manner, whereas an E(2) antagonist reversed these effects. The nucleotide -200/-1 region of promoter I.f conferred E(2) responsiveness. Two activator protein 1 (AP-1) elements in this region were essential for induction of promoter activity by E(2). ESR1 and JUN (c-Jun) bound to these AP-1 motifs in intact cells and under cell-free conditions. The addition of an ESR1 mutant that interacts with JUN but not directly with DNA enhanced E(2)-dependent promoter I.f activity. Independently, we demonstrated an interaction between ESR1 and JUN in hypothalamic cells. Knockdown of ESR1 abolished E(2)-induced aromatase mRNA and enzyme activity. Taken together, E(2) regulates Cyp19a1 expression via promoter I.f by enhanced binding of an ESR1/JUN complex to distinct AP-1 motifs in hypothalamic cells. We speculate that this mechanism may, in part, regulate gonadotropin secretion and sexual activity.


Asunto(s)
Aromatasa/metabolismo , Receptor alfa de Estrógeno/metabolismo , Hipotálamo/metabolismo , Neuronas/metabolismo , Regiones Promotoras Genéticas/fisiología , Análisis de Varianza , Animales , Aromatasa/genética , Western Blotting , Línea Celular , Células Cultivadas , Inmunoprecipitación de Cromatina , Relación Dosis-Respuesta a Droga , Ensayo de Cambio de Movilidad Electroforética , Pruebas de Enzimas , Estradiol/análogos & derivados , Estradiol/farmacología , Antagonistas de Estrógenos/farmacología , Estrógenos/farmacología , Fulvestrant , Hipotálamo/citología , Hipotálamo/efectos de los fármacos , Ratones , Neuronas/citología , Neuronas/efectos de los fármacos , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas c-fos/genética , Proteínas Proto-Oncogénicas c-fos/metabolismo , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Tiempo , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismo , Transfección
15.
J Neurosci ; 29(29): 9390-5, 2009 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-19625529

RESUMEN

Kisspeptin is a product of the Kiss1 gene and is expressed in the forebrain. Neurons that express Kiss1 play a crucial role in the regulation of pituitary luteinizing hormone secretion and reproduction. These neurons are the direct targets for the action of estradiol-17beta (E(2)), which acts via the estrogen receptor alpha isoform (ER alpha) to regulate Kiss1 expression. In the arcuate nucleus (Arc), where the dynorphin gene (Dyn) is expressed in Kiss1 neurons, E(2) inhibits the expression of Kiss1 mRNA. However, E(2) induces the expression of Kiss1 in the anteroventral periventricular nucleus (AVPV). The mechanism for differential regulation of Kiss1 in the Arc and AVPV by E(2) is unknown. ER alpha signals through multiple pathways, which can be categorized as either classical, involving the estrogen response element (ERE), or nonclassical, involving ERE-independent mechanisms. To elucidate the molecular basis for the action of E(2) on Kiss1 and Dyn expression, we studied the effects of E(2) on Kiss1 and Dyn mRNAs in the brains of mice bearing targeted alterations in the ER alpha signaling pathways. We found that stimulation of Kiss1 expression by E(2) in the AVPV and inhibition of Dyn in the Arc required an ERE-dependent pathway, whereas the inhibition of Kiss1 expression by E(2) in the Arc involved ERE-independent mechanisms. Thus, distinct ER alpha signaling pathways can differentially regulate the expression of identical genes across different brain regions, and E(2) can act within the same neuron through divergent ER alpha signaling pathways to regulate different neurotransmitter genes.


Asunto(s)
Encéfalo/efectos de los fármacos , Dinorfinas/metabolismo , Estradiol/farmacología , Receptor alfa de Estrógeno/metabolismo , Estrógenos/farmacología , Proteínas/metabolismo , Animales , Núcleos Talámicos Anteriores/efectos de los fármacos , Núcleos Talámicos Anteriores/metabolismo , Núcleo Arqueado del Hipotálamo/efectos de los fármacos , Núcleo Arqueado del Hipotálamo/metabolismo , Encéfalo/metabolismo , Dinorfinas/genética , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Sustitución del Gen , Kisspeptinas , Hormona Luteinizante/sangre , Ratones , Ratones Transgénicos , Núcleos Talámicos de la Línea Media/efectos de los fármacos , Núcleos Talámicos de la Línea Media/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Proteínas/genética , ARN Mensajero/metabolismo , Transducción de Señal
16.
Proc Natl Acad Sci U S A ; 106(17): 7221-6, 2009 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-19359483

RESUMEN

Nonclassical estrogen receptor alpha (ERalpha) signaling can mediate E(2) negative feedback actions in the reproductive axis; however, downstream pathways conveying these effects remain unclear. These studies tested the hypothesis that p21-activated kinase 1 (PAK1), a serine/threonine kinase rapidly activated by E(2) in nonneural cells, functions as a downstream node for E(2) signaling pathways in cells of the preoptic area, and it may thereby mediate E(2) negative feedback effects. Treatment of ovariectomized (OVX) rats with estradiol benzoate (EB) caused rapid and transient induction of phosphorylated PAK1 immunoreactivity in the medial preoptic nucleus (MPN) but not the arcuate nucleus. To determine whether rapid induction of PAK phosphorylation by E(2) is mediated by nonclassical [estrogen response element (ERE)-independent] ERalpha signaling, we used female ERalpha null (ERalpha(-/-)) mice possessing an ER knock-in mutation (E207A/G208A; AA), in which the mutant ERalpha is incapable of binding DNA and can signal only through membrane-initiated or ERE-independent genotropic pathways (ERalpha(-/AA) mice). After 1-h EB treatment, the number of pPAK1-immunoreactive cells in the MPN was increased in both wild-type (ERalpha(+/+)) and ERalpha(-/AA) mice but was unchanged in ERalpha(-/-) mice. Serum luteinizing hormone (LH) was likewise suppressed within 1 h after EB treatment in ERalpha(+/+) and ERalpha(-/AA) but not ERalpha(-/ -) mice. In OVX rats, 5-min intracerebroventricular infusion of a PAK inhibitor peptide but not control peptide blocked rapid EB suppression of LH secretion. Taken together, our findings implicate PAK1 activation subsequent to nonclassical ERalpha signaling as an important component of the negative feedback actions of E(2) in the brain.


Asunto(s)
Estradiol/farmacología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Quinasas p21 Activadas/metabolismo , Animales , Receptor alfa de Estrógeno/deficiencia , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Femenino , Hormona Luteinizante/metabolismo , Ratones , Ratones Noqueados , Fosforilación , Ratas , Transducción de Señal , Factores de Tiempo , Quinasas p21 Activadas/genética
17.
Endocrinology ; 149(12): 6198-206, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18719025

RESUMEN

The estrogen receptor-alpha (ERalpha) acts through multiple pathways, including estrogen response element (ERE)-dependent (classical) and ERE-independent (nonclassical) mechanisms. We previously created a mouse model harboring a two-amino-acid mutation of the DNA-binding domain (E207A, G208A) that precludes direct binding of ERalpha to an ERE. After crossing heterozygous mutant mice with an ERalpha knockout (ERKO) line, it was possible to assess the degree of physiological rescue by the isolated ERalpha nonclassical allele (-/AA; AA) when compared with ERKO mice (-/-) and to wild type (+/+; WT). In male ERKO mice up to 8 months of age, testosterone levels were high, although LH levels were similar to WT. Testosterone was normal in the AA mice, indicating that the AA allele rescues the enhanced testosterone biosynthesis in ERKO mice. Male ERKO mice exhibited distention of the seminiferous tubules as early as 2-3 months of age as a consequence of decreased water resorption in the efferent ducts. By 3-4 months of age, ERKO mice had impaired spermatogenesis in approximately 40% of their tubules, and sperm counts and motility declined in association with the histological changes. In the AA mice, histological defects were greatly reduced or absent, and sperm counts and motility were rescued. Levels of aquaporins 1 and 9, which contribute to water uptake in the efferent ducts, were reduced in ERKO mice and partially or fully rescued in AA mice, whereas another water transporter, sodium-hydrogen exchanger-3, was decreased in both ERKO and AA mice. We conclude that non-ERE-dependent estrogen pathways are sufficient to rescue the defective spermatogenesis observed in ERKO mice and play a prominent role in ERalpha action in the testis, including pathways that regulate water resorption and androgen biosynthesis.


Asunto(s)
Receptor alfa de Estrógeno/fisiología , Estrógenos/farmacología , Elementos de Respuesta/genética , Túbulos Seminíferos/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Animales , Western Blotting , Receptor alfa de Estrógeno/genética , Hormona Folículo Estimulante/sangre , Inmunohistoquímica , Hormona Luteinizante/sangre , Masculino , Ratones , Ratones Noqueados , Mutación , Túbulos Seminíferos/citología , Túbulos Seminíferos/metabolismo , Transducción de Señal/genética , Transducción de Señal/fisiología , Recuento de Espermatozoides , Motilidad Espermática , Espermatogénesis/efectos de los fármacos , Testosterona/sangre
18.
Endocrinology ; 149(11): 5328-34, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18635656

RESUMEN

During the female reproductive cycle, the neuroendocrine action of estradiol switches from negative feedback to positive feedback to initiate the preovulatory GnRH and subsequent LH surges. Estrogen receptor-alpha (ERalpha) is required for both estradiol negative and positive feedback regulation of LH. ERalpha may signal through estrogen response elements (EREs) in DNA and/or via ERE-independent pathways. Previously, a knock-in mutant allele (ERalpha-/AA) that selectively restores ERE-independent signaling onto the ERalpha-/- background was shown to confer partial negative but not positive estradiol feedback on serum LH. The current study investigated the roles of the ERE-dependent and ERE-independent ERalpha pathways for estradiol feedback at the level of GnRH neuron firing activity. The above ERalpha genetic models were crossed with GnRH-green fluorescent protein mice to enable identification of GnRH neurons in brain slices. Targeted extracellular recordings were used to monitor GnRH neuron firing activity using an ovariectomized, estradiol-treated mouse model that exhibits diurnal switches between negative and positive feedback. In wild-type mice, GnRH neuron firing decreased in response to estradiol during negative feedback and increased during positive feedback. In contrast, both positive and negative responses to estradiol were absent in GnRH neurons from ERalpha-/- and ERalpha-/AA mice. ERE-dependent signaling is thus required to increase GnRH neuron firing to generate a GnRH/LH surge. Furthermore, ERE-dependent and -independent ERalpha signaling pathways both appear necessary to mediate estradiol negative feedback on serum LH levels, suggesting central and pituitary estradiol feedback may use different combinations of ERalpha signaling pathways.


Asunto(s)
Receptor alfa de Estrógeno/fisiología , Retroalimentación Fisiológica/genética , Hormona Liberadora de Gonadotropina/metabolismo , Neuronas/fisiología , Transmisión Sináptica/genética , Animales , Electrofisiología , Estradiol/sangre , Estradiol/metabolismo , Estradiol/farmacología , Receptor alfa de Estrógeno/genética , Retroalimentación Fisiológica/efectos de los fármacos , Femenino , Hormona Luteinizante/sangre , Hormona Luteinizante/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/metabolismo , Ovariectomía , Hipófisis/metabolismo , Hipófisis/fisiología , Elementos de Respuesta/efectos de los fármacos , Elementos de Respuesta/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética
19.
Mol Cell Endocrinol ; 290(1-2): 24-30, 2008 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-18534740

RESUMEN

Estrogen receptor alpha (ERalpha) mediates estrogen (E2) actions in the brain and is critical for normal reproductive function and behavior. In the classical pathway, ERalpha binds to estrogen response elements (EREs) to regulate gene transcription. ERalpha can also participate in several non-classical pathways, including ERE-independent gene transcription via protein-protein interactions with transcription factors and rapid, non-genotropic pathways. To distinguish between ERE-dependent and ERE-independent mechanisms of E2 action in vivo, we have created ERalpha null mice that possess an ER knock-in mutation (E207A/G208A; "AA"), in which the mutant ERalpha cannot bind to DNA but retains activity in ERE-independent pathways (ERalpha(-/AA) mice). Understanding the molecular mechanisms of ERalpha action will be helpful in developing pharmacological therapies that differentiate between ERE-dependent and ERE-independent processes. This review focuses on how the ERalpha(-/AA) model has contributed to our knowledge of ERalpha signaling mechanisms in estrogen regulation of the reproductive axis and sexual behavior.


Asunto(s)
Estrógenos/metabolismo , Receptores de Estrógenos/metabolismo , Animales , Estrógenos/farmacología , Retroalimentación Fisiológica/efectos de los fármacos , Ratones , Ratones Noqueados , Reproducción/efectos de los fármacos , Conducta Sexual Animal/efectos de los fármacos
20.
Endocrinology ; 148(11): 5288-94, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17673514

RESUMEN

Estrogen receptor (ER)-alpha mediates estradiol (E(2)) actions in the male gonads and brain and is critical for normal male reproductive function. In the classical pathway, ERalpha binds to estrogen response elements (EREs) to regulate gene transcription. ERalpha can also regulate gene transcription independently of EREs via protein-protein interactions with transcription factors and additionally signal via rapid, nongenomic pathways originating at the cell membrane. This study assessed the degree to which ERE-independent ERalpha signaling can rescue the disrupted masculine sexual behaviors and elevated serum testosterone (T) levels that have been shown to result from ERalpha gene deletion. We utilized male ERalpha null mice that possess a ER knock-in mutation (E207A/G208A; AA), in which the mutant ERalpha is incapable of binding to DNA and can signal only through ERE-independent pathways (ERalpha(-/AA) mice). We found that sexual behavior, including mounting, is virtually absent in ERalpha(-/-) and ERalpha(-/AA) males, suggesting that ERE-independent signaling is insufficient to maintain any degree of normal sexual behavior in the absence of ERE binding. By contrast, ERE-independent signaling in the ERalpha(-/AA) mouse is sufficient to restore serum T levels to values observed in wild-type males. These data indicate that binding of ERs to EREs mediates most if not all of E(2)'s effects on male sexual behavior, whereas ERE-independent ERalpha signaling may mediate E(2)'s inhibitory effects on T production.


Asunto(s)
Estradiol/fisiología , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/fisiología , Elementos de Respuesta/fisiología , Conducta Sexual Animal/fisiología , Testosterona/metabolismo , Animales , Femenino , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factores Sexuales , Transducción de Señal/fisiología , Testosterona/sangre
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA