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1.
Urology ; 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39173930

RESUMO

OBJECTIVE: To assess how race, ethnicity, primary language, clinical and other sociodemographic factors predict surgical treatment for pelvic organ prolapse (POP) in a minority-majority Hispanic population. METHODS: We identified patients with POP ICD-10 codes from Oct 2019 to Dec 2022 at our Urogynecology academic practice. Data were collected by chart review. Covariates were obtained by manual abstraction. Continuous and categorical variables were analyzed using t-test and chi-square test, and Wilcoxon rank-sum test for non-parametric data. A logistic regression model was fitted to identify independent predictors of surgery. RESULTS: Of 943 patients over 38 months, 441 (46.8%) underwent surgery. On univariate analysis, younger age, Hispanic/Latino ethnicity, Spanish as primary language, private insurance, stage of prolapse and obesity correlated with higher rates of surgical treatment. On multivariate regression, only age and prolapse compartment remained significant predictors. Younger age and apical prolapse increased the likelihood of surgery (OR=.98 [.96-.99], P = <.001; R=2.31 [1.13-4.72], P = <.001, respectively). CONCLUSION: Controlling for confounders, age, and apical prolapse compartment predicted surgical treatment for POP in our Hispanic minority-majority population. Previously identified barriers to care including minority status and non-English primary language do not appear to exist in our population. This may be related to linguistic, ethnic, and racial concordance between healthcare staff and patients, alongside protective aspects of ethnic enclaves. Further research is warranted to understand the impact of cultural barriers, such as provider language, on patient-provider dynamics and surgical decision-making.

3.
J Neurosci ; 42(2): 325-348, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34819339

RESUMO

Globally, more than 67 million people are living with the effects of ischemic stroke. Importantly, many stroke survivors develop a chronic inflammatory response that may contribute to cognitive impairment, a common and debilitating sequela of stroke that is insufficiently studied and currently untreatable. 2-Hydroxypropyl-ß-cyclodextrin (HPßCD) is an FDA-approved cyclic oligosaccharide that can solubilize and entrap lipophilic substances. The goal of the present study was to determine whether the repeated administration of HPßCD curtails the chronic inflammatory response to stroke by reducing lipid accumulation within stroke infarcts in a distal middle cerebral artery occlusion mouse model of stroke. To achieve this goal, we subcutaneously injected young adult and aged male mice with vehicle or HPßCD 3 times per week, with treatment beginning 1 week after stroke. We evaluated mice at 7 weeks following stroke using immunostaining, RNA sequencing, lipidomic, and behavioral analyses. Chronic stroke infarct and peri-infarct regions of HPßCD-treated mice were characterized by an upregulation of genes involved in lipid metabolism and a downregulation of genes involved in innate and adaptive immunity, reactive astrogliosis, and chemotaxis. Correspondingly, HPßCD reduced the accumulation of lipid droplets, T lymphocytes, B lymphocytes, and plasma cells in stroke infarcts. Repeated administration of HPßCD also preserved NeuN immunoreactivity in the striatum and thalamus and c-Fos immunoreactivity in hippocampal regions. Additionally, HPßCD improved recovery through the protection of hippocampal-dependent spatial working memory and reduction of impulsivity. These results indicate that systemic HPßCD treatment following stroke attenuates chronic inflammation and secondary neurodegeneration and prevents poststroke cognitive decline.SIGNIFICANCE STATEMENT Dementia is a common and debilitating sequela of stroke. Currently, there are no available treatments for poststroke dementia. Our study shows that lipid metabolism is disrupted in chronic stroke infarcts, which causes an accumulation of uncleared lipid debris and correlates with a chronic inflammatory response. To our knowledge, these substantial changes in lipid homeostasis have not been previously recognized or investigated in the context of ischemic stroke. We also provide a proof of principle that solubilizing and entrapping lipophilic substances using HPßCD could be an effective strategy for treating chronic inflammation after stroke and other CNS injuries. We propose that using HPßCD for the prevention of poststroke dementia could improve recovery and increase long-term quality of life in stroke sufferers.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/uso terapêutico , Encéfalo/efeitos dos fármacos , Infarto da Artéria Cerebral Média/tratamento farmacológico , Inflamação/tratamento farmacológico , Fatores Etários , Animais , Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Inflamação/metabolismo , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Resultado do Tratamento
4.
J Pharmacol Exp Ther ; 380(2): 126-141, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34893553

RESUMO

The aim of this study was to test whether poststroke oral administration of a small molecule p75 neurotrophin receptor (p75NTR) modulator (LM11A-31) can augment neuronal survival and improve recovery in a mouse model of stroke. Mice were administered LM11A-31 for up to 12 weeks, beginning 1 week after stroke. Metabolomic analysis revealed that after 2 weeks of daily treatment, mice that received LM11A-31 were distinct from vehicle-treated mice by principal component analysis and had higher levels of serotonin, acetylcholine, and dopamine in their ipsilateral hemisphere. LM11A-31 treatment also improved redox homeostasis by restoring reduced glutathione. It also offset a stroke-induced reduction in glycolysis by increasing acetyl-CoA. There was no effect on cytokine levels in the infarct. At 13 weeks after stroke, adaptive immune cell infiltration in the infarct was unchanged in LM11A-31-treated mice, indicating that LM11A-31 does not alter the chronic inflammatory response to stroke at the site of the infarct. However, LM11A-31-treated mice had less brain atrophy, neurodegeneration, tau pathology, and microglial activation in other regions of the ipsilateral hemisphere. These findings correlated with improved recovery of motor function on a ladder test, improved sensorimotor and cognitive abilities on a nest construction test, and less impulsivity in an open field test. These data support small molecule modulation of the p75NTR for preserving neuronal health and function during stroke recovery. SIGNIFICANCE STATEMENT: The findings from this study introduce the p75 neurotrophin receptor as a novel small molecule target for promotion of stroke recovery. Given that LM11A-31 is in clinical trials as a potential therapy for Alzheimer's disease, it could be considered as a candidate for assessment in stroke or vascular dementia studies.


Assuntos
Infarto da Artéria Cerebral Média/tratamento farmacológico , Isoleucina/análogos & derivados , Morfolinas/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Glutationa/metabolismo , Glicólise , Infarto da Artéria Cerebral Média/metabolismo , Isoleucina/farmacologia , Isoleucina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Morfolinas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Neurotransmissores/metabolismo , Receptor de Fator de Crescimento Neural/metabolismo
5.
PLoS One ; 15(9): e0238777, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32886719

RESUMO

BACKGROUND: Obstetric fistula significantly impacts women's mental health and well-being. Routine screening for mental health in fistula repair programs can be a gateway to link patients to services, and can produce routine data to inform programmatic investments. This study observed the integration of a mental health screening program into an obstetric fistula repair program in Mali, with two specific objectives: 1) to describe the social and mental health well-being of women presenting with obstetric fistulas in Mali, and 2) to document the impact of the mental health screening pilot on policy change in Mali. METHODS: Seven fistula repair campaigns were conducted between June 2016 and May 2017. All individuals presenting for fistula repair completed a mental health assessment at intake, including a depression screener (PHQ-9) and an assessment of psycho-social impacts of fistula. The depression screener was repeated three months following inpatient discharge. Findings were shared with stakeholders in Mali and impacts on policy were documented. RESULTS: Of 207 women who presented for fistula repair, 167 patients completed the mental health assessment at surgical intake, and 130 patients repeated the screener at 3-month follow-up. At intake, 36.5% of women had moderate or severe depression, decreasing to 16.9% at follow-up. The mean depression score differed significantly by timepoint (9.14 vs. 6.72, p <0.001). Results were shared in a report with stakeholders, and consultations with the Mali Ministry of Health. As a result of advocacy, mental health was a key component of Mali's National Fistula Prevention and Treatment Strategy (2018-2022). CONCLUSION: The high prevalence of depression in Malian fistula patients underscores a need for more robust mental health support for patients after surgery. Data on mental health from routine screening informs community reintegration strategies for individual patients, elevates the overall quality of care of fistula repair programs by addressing patients' holistic health needs, and contributes to evidence-informed decision-making and data-driven policy change within the larger health system.


Assuntos
Transtorno Depressivo/epidemiologia , Complicações do Trabalho de Parto/psicologia , Fístula Vesicovaginal/psicologia , Adulto , Feminino , Humanos , Mali/epidemiologia , Saúde Mental/estatística & dados numéricos , Pessoa de Meia-Idade , Gravidez , Adulto Jovem
6.
eNeuro ; 5(5)2018.
Artigo em Inglês | MEDLINE | ID: mdl-30417081

RESUMO

Here we used mouse models of heart and brain ischemia to compare the inflammatory response to ischemia in the heart, a protein rich organ, to the inflammatory response to ischemia in the brain, a lipid rich organ. We report that ischemia-induced inflammation resolves between one and four weeks in the heart compared to between eight and 24 weeks in the brain. Importantly, we discovered that a second burst of inflammation occurs in the brain between four and eight weeks following ischemia, which coincided with the appearance of cholesterol crystals within the infarct. This second wave shares a similar cellular and molecular profile with atherosclerosis and is characterized by high levels of osteopontin (OPN) and matrix metalloproteinases (MMPs). In order to test the role of OPN in areas of liquefactive necrosis, OPN-/- mice were subjected to brain ischemia. We found that at seven weeks following stroke, the expression of pro-inflammatory proteins and MMPs was profoundly reduced in the infarct of the OPN-/- mice, although the number of cholesterol crystals was increased. OPN-/- mice exhibited faster recovery of motor function and a higher number of neuronal nuclei (NeuN) positive cells in the peri-infarct area at seven weeks following stroke. Based on these findings we propose that the brain liquefies after stroke because phagocytic cells in the infarct are unable to efficiently clear cholesterol rich myelin debris, and that this leads to the perpetuation of an OPN-dependent inflammatory response characterized by high levels of degradative enzymes.


Assuntos
Aterosclerose/complicações , Isquemia Encefálica/complicações , Encéfalo/patologia , Osteopontina/farmacologia , Acidente Vascular Cerebral/complicações , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Doenças Neurodegenerativas/patologia , Acidente Vascular Cerebral/metabolismo
7.
Acta Neuropathol Commun ; 4(1): 100, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27600707

RESUMO

This study provides a parallel characterization of the cytokine and chemokine response to stroke in the human and mouse brain at different stages of infarct resolution. The study goal was to address the hypothesis that chronic inflammation may contribute to stroke-related dementia. We used C57BL/6 and BALB/c mice to control for strain related differences in the mouse immune response. Our data indicate that in both mouse strains, and humans, there is increased granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), interleukin-12 p70 (IL-12p70), interferon gamma-induced protein-10 (IP-10), keratinocyte chemoattractant/interleukin-8 (KC/IL-8), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), macrophage inflammatory protein-1ß (MIP-1ß), regulated on activation, normal T cell expressed and secreted (RANTES), and Tumor necrosis factor-α (TNF-α) in the infarct core during the acute time period. Nevertheless, correlation and two-way ANOVA analyses reveal that despite this substantial overlap between species, there are still significant differences, particularly in the regulation of granulocyte colony-stimulating factor (G-CSF), which is increased in mice but not in humans. In the weeks after stroke, during the stage of liquefactive necrosis, there is significant resolution of the inflammatory response to stroke within the infarct. However, CD68+ macrophages remain present, and levels of IL-6 and MCP-1 remain chronically elevated in infarcts from both mice and humans. Furthermore, there is a chronic T cell response within the infarct in both species. This response is differentially polarized towards a T helper 1 (Th1) response in C57BL/6 mice, and a T helper 2 (Th2) response in BALB/c mice, suggesting that the chronic inflammatory response to stroke may follow a different trajectory in different patients. To control for the fact that the average age of the patients used in this study was 80 years, they were of both sexes, and many had suffered from multiple strokes, we also present findings that reveal how the chronic inflammatory response to stroke is impacted by age, sex, and multiple strokes in mice. Our data indicate that the chronic cytokine and chemokine response to stroke is not substantially altered in 18-month old compared to 3-month old C57BL/6 mice, although T cell infiltration is attenuated. We found a significant correlation in the chronic cytokine response to stroke in males and females. However, the chronic cytokine response to stroke was mildly exacerbated by a recurrent stroke in both C57BL/6 and BALB/c mice.


Assuntos
Infarto Encefálico/imunologia , Encéfalo/imunologia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Encéfalo/patologia , Infarto Encefálico/patologia , Doença Crônica , Feminino , Humanos , Imunoensaio , Imuno-Histoquímica , Infarto da Artéria Cerebral Média , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Recidiva , Caracteres Sexuais , Especificidade da Espécie
8.
J Neurosci ; 35(5): 2133-45, 2015 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-25653369

RESUMO

Each year, 10 million people worldwide survive the neurologic injury associated with a stroke. Importantly, stroke survivors have more than twice the risk of subsequently developing dementia compared with people who have never had a stroke. The link between stroke and the later development of dementia is not understood. There are reports of oligoclonal bands in the CSF of stroke patients, suggesting that in some people a B-lymphocyte response to stroke may occur in the CNS. Therefore, we tested the hypothesis that a B-lymphocyte response to stroke could contribute to the onset of dementia. We discovered that, in mouse models, activated B-lymphocytes infiltrate infarcted tissue in the weeks after stroke. B-lymphocytes undergo isotype switching, and IgM, IgG, and IgA antibodies are found in the neuropil adjacent to the lesion. Concurrently, mice develop delayed deficits in LTP and cognition. Genetic deficiency, and the pharmacologic ablation of B-lymphocytes using an anti-CD20 antibody, prevents the appearance of delayed cognitive deficits. Furthermore, immunostaining of human postmortem tissue revealed that a B-lymphocyte response to stroke also occurs in the brain of some people with stroke and dementia. These data suggest that some stroke patients may develop a B-lymphocyte response to stroke that contributes to dementia, and is potentially treatable with FDA-approved drugs that target B cells.


Assuntos
Subpopulações de Linfócitos B/imunologia , Demência/etiologia , Infarto da Artéria Cerebral Média/imunologia , Idoso , Animais , Estudos de Casos e Controles , Demência/imunologia , Demência/fisiopatologia , Feminino , Humanos , Imunoglobulinas/imunologia , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/fisiopatologia , Potenciação de Longa Duração , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
9.
Brain Res ; 1298: 1-12, 2009 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-19729001

RESUMO

Although androgens induce numerous actions in brain, relatively little is known about which cell signaling pathways androgens activate in neurons. Recent work in our laboratory showed that the androgens testosterone and dihydrotestosterone (DHT) activate androgen receptor (AR)-dependent mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling. Since the transcription factor cyclic AMP response element binding protein (CREB) is a downstream effector of MAPK/ERK and androgens activate CREB in non-neuronal cells, we investigated whether androgens activate CREB signaling in neurons. First, we observed that DHT rapidly activates CREB in cultured hippocampal neurons, as evidenced by CREB phosphorylation. Further, we observed that DHT-induced CREB phosphorylation is AR-dependent, as it occurs in PC12 cells stably transfected with AR but in neither wild-type nor empty vector-transfected cells. Next, we sought to identify the signal transduction pathways upstream of CREB phosphorylation using pharmacological inhibitors. DHT-induced CREB phosphorylation in neurons was found to be dependent upon protein kinase C (PKC) signaling but independent of MAPK/ERK, phosphatidylinositol 3-kinase, protein kinase A, and Ca(2+)/calmodulin-dependent protein kinase IV. These results demonstrate that DHT induces PKC-dependent CREB signaling, which may contribute to androgen-mediated neural functions.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Di-Hidrotestosterona/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Análise de Variância , Androgênios/metabolismo , Androgênios/farmacologia , Animais , Western Blotting , Células Cultivadas , Di-Hidrotestosterona/farmacologia , Hipocampo/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Células PC12 , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Transfecção
10.
J Neurochem ; 105(6): 2477-88, 2008 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-18346198

RESUMO

Age-related testosterone depletion in men is a risk factor for Alzheimer's disease. Prior studies suggest that androgens affect Alzheimer's disease risk by regulating accumulation of beta-amyloid protein (Abeta) by an undefined mechanism. In this study, we investigated the role of the Abeta-catabolizing enzyme neprilysin (NEP) in this process. First, we observed that androgens positively regulate neural expression of NEP in adult male rats. Next, we investigated androgen regulatory effects on both NEP expression and Abeta levels using cultured hippocampal neurons and neuronally differentiated rat pheochromocytoma cell 12 with or without androgen receptor (AR). Dihydrotestosterone (DHT) induced a time-dependent increase in NEP expression. DHT also significantly decreased levels of Abeta in AR-expressing cells transfected with amyloid precursor protein, but did not affect levels of either full-length or non-amyloidogenic, soluble amyloid precursor protein. Importantly, the DHT induced decrease of Abeta was blocked by pharmacological inhibition of NEP. The DHT-mediated increase in NEP expression and decrease in Abeta levels were (i) not observed in rat pheochromocytoma cell 12 lacking AR and (ii) blocked in AR-expressing cells by the antagonists, cyproterone acetate and flutamide. Together, these findings suggest that androgen regulation of Abeta involves an AR-dependent mechanism requiring up-regulation of the Abeta catabolizing enzyme NEP.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/metabolismo , Androgênios/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Neprilisina/biossíntese , Animais , Encéfalo/enzimologia , Encéfalo/metabolismo , Células Cultivadas , Humanos , Masculino , Neprilisina/genética , Neprilisina/fisiologia , Células PC12 , Ratos , Ratos Sprague-Dawley , Receptores Androgênicos/fisiologia , Regulação para Cima/fisiologia
11.
Endocrinology ; 148(6): 2936-43, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17347309

RESUMO

Androgens can exert profound effects on the organization, development, and function of the nervous system through activation of androgen receptors (ARs). Nonsteroidal and steroidal antiandrogens antagonize AR-mediated, classic genomic actions of androgens. However, emerging studies in nonneuronal cells indicate that antiandrogens can act as partial agonists for the AR. Here we investigated the effects of the antiandrogens flutamide and cyproterone acetate on neuroprotection induced by dihydrotestosterone (DHT). We observed that, although flutamide and cyproterone acetate blocked androgen-induced gene expression, they failed to inhibit DHT protection against apoptotic insults in cultured hippocampal neurons. Interestingly, flutamide and cyproterone acetate alone, like DHT, significantly reduced apoptosis. Furthermore, the protective actions of flutamide and cyproterone acetate were observed specifically in AR-expressing cell lines, suggesting a role for AR in the agonist effects of antiandrogens. Our results indicate that, in contrast to the classic antiandrogen properties of flutamide and cyproterone acetate, these AR modulators display agonist activities at the level of neuroprotection. These findings provide new insight into the agonist vs. antagonist properties of antiandrogens, information that will be crucial to understanding the neural implications of clinically used AR-modulating drugs.


Assuntos
Androgênios , Acetato de Ciproterona/farmacologia , Flutamida/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptores Androgênicos/fisiologia , Antagonistas de Androgênios/farmacologia , Antagonistas de Receptores de Andrógenos , Animais , Animais Recém-Nascidos , Regulação da Expressão Gênica/efeitos dos fármacos , Mimetismo Molecular , Células PC12 , Ratos , Ratos Sprague-Dawley
12.
J Neurosci ; 27(6): 1422-33, 2007 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-17287517

RESUMO

Estrogen is neuroprotective against a variety of insults, including beta-amyloid peptide (Abeta); however, the underlying mechanism(s) is not fully understood. Here, we report that 17beta-estradiol (E2) selectively regulates neuronal expression of the Bcl-2 family (bcl-2, bcl-x, bcl-w, bax, bak, bad, bik, bnip3, bid, and bim). In primary cerebrocortical neuron cultures under basal conditions, we observe that E2 upregulates expression of antiapoptotic Bcl-w and downregulates expression of proapoptotic Bim in an estrogen receptor (ER)-dependent manner. In the presence of toxic levels of Abeta, we observe that E2 attenuates indices of neuronal apoptosis: c-Jun N-terminal kinase (JNK)-dependent downregulation of Bcl-w and upregulation of Bim, mitochondrial release of cytochrome c and Smac, and cell death. These neuroprotective effects of E2 against Abeta-induced apoptosis are mimicked by the JNK inhibitor SP600125 (anthra[1,9-cd]pyrazol-6(2H)-one). In addition, E2 attenuates Abeta-induced JNK phosphorylation in an ER-dependent manner, but does not affect basal levels of JNK phosphorylation. These results suggest that E2 may reduce Abeta-induced neuronal apoptosis at least in part by two complementary pathways: (1) ER-dependent, JNK-independent upregulation of Bcl-w and downregulation of Bim under basal conditions, and (2) ER-dependent inhibition of Abeta-induced JNK activation and subsequent JNK-dependent downregulation of Bcl-w and upregulation of Bim, resulting in mitochondrial release of cytochrome c and Smac and eventual cell death. These data provide new understanding into the mechanisms contributing to estrogen neuroprotection, a neural function with potential therapeutic relevance to Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Proteínas Reguladoras de Apoptose/biossíntese , Apoptose/efeitos dos fármacos , Estradiol/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Proteínas de Membrana/biossíntese , Proteínas do Tecido Nervoso/biossíntese , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/biossíntese , Animais , Antracenos/farmacologia , Apoptose/fisiologia , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Proteínas de Transporte/análise , Córtex Cerebral/citologia , Citocromos c/análise , Ativação Enzimática/efeitos dos fármacos , Estradiol/análogos & derivados , Estradiol/fisiologia , Moduladores de Receptor Estrogênico/farmacologia , Fulvestranto , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas de Membrana/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Proteínas Mitocondriais/análise , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Neurônios/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2 , RNA Mensageiro/biossíntese , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
13.
J Neurochem ; 94(6): 1639-51, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16011741

RESUMO

Recent evidence indicates that testosterone is neuroprotective, however, the underlying mechanism(s) remains to be elucidated. In this study, we investigated the hypothesis that androgens induce mitogen-activated protein kinase (MAPK) signaling in neurons, which subsequently drives neuroprotection. We observed that testosterone and its non-aromatizable metabolite dihydrotestosterone (DHT) rapidly and transiently activate MAPK in cultured hippocampal neurons, as evidenced by phosphorylation of extracellular signal-regulated kinase (ERK)-1 and ERK-2. Importantly, pharmacological suppression of MAPK/ERK signaling blocked androgen-mediated neuroprotection against beta-amyloid toxicity. Androgen activation of MAPK/ERK and neuroprotection also was observed in PC12 cells stably transfected with androgen receptor (AR), but in neither wild-type nor empty vector-transfected PC12 cells. Downstream of ERK phosphorylation, we observed that DHT sequentially increases p90 kDa ribosomal S6 kinase (Rsk) phosphorylation and phosphorylation-dependent inactivation of Bcl-2-associated death protein (Bad). Prevention of androgen-induced phosphorylation of Rsk and Bad blocked androgen neuroprotection. These findings demonstrate AR-dependent androgen activation of MAPK/ERK signaling in neurons, and specifically identify a neuroprotective pathway involving downstream activation of Rsk and inactivation of Bad. Elucidation of androgen-mediated neural signaling cascades will provide important insights into the mechanisms of androgen action in brain, and may present a framework for therapeutic intervention of age-related neurodegenerative disorders.


Assuntos
Androgênios/metabolismo , Encéfalo/metabolismo , Citoproteção/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neurônios/metabolismo , Fármacos Neuroprotetores/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/toxicidade , Androgênios/farmacologia , Animais , Proteínas de Transporte/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Células Cultivadas , Citoproteção/efeitos dos fármacos , Di-Hidrotestosterona/metabolismo , Di-Hidrotestosterona/farmacologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Inibidores Enzimáticos/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Células PC12 , Fosforilação/efeitos dos fármacos , Proteínas Quinases/efeitos dos fármacos , Proteínas Quinases/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Androgênicos/genética , Proteínas Quinases S6 Ribossômicas , Testosterona/metabolismo , Testosterona/farmacologia , Proteína de Morte Celular Associada a bcl
14.
J Neurosci ; 25(5): 1149-58, 2005 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-15689551

RESUMO

beta-Amyloid protein (Abeta) has been implicated as a key molecule in the neurodegenerative cascades of Alzheimer's disease (AD). Abeta directly induces neuronal apoptosis, suggesting an important role of Abeta neurotoxicity in AD neurodegeneration. However, the mechanism(s) of Abeta-induced neuronal apoptosis remain incompletely defined. In this study, we report that Abeta-induced neuronal death is preceded by selective alterations in expression of the Bcl-2 family of apoptosis-related genes. Specifically, we observe that Abeta significantly reduces expression of antiapoptotic Bcl-w and Bcl-x(L), mildly affects expression of bim, Bcl-2, and bax, but does not alter expression of bak, bad, bik, bid, or BNIP3.Abeta-induced downregulation of Bcl-w appears to contribute to the mechanism of apoptosis, because Abeta-induced neuronal death was significantly increased by Bcl-w suppression but significantly reduced by Bcl-w overexpression. Downstream of Bcl-w, Abeta-induced neuronal apoptosis is characterized by mitochondrial release of second mitochondrion-derived activator of caspase (Smac), an important precursor event to cell death. We observed that Smac release was potentiated by suppression of Bcl-w and reduced by overexpression of Bcl-w. Next, we investigated the upstream mediator of Abeta-induced Bcl-w downregulation and Smac release. We observed that Abeta rapidly activates c-Jun N-terminal kinase (JNK). Pharmacological inhibition of JNK effectively inhibited all measures of Abeta apoptosis: Bcl-w downregulation, Smac release, and neuronal death. Together, these results suggest that the mechanism of Abeta-induced neuronal apoptosis sequentially involves JNK activation, Bcl-w downregulation, and release of mitochondrial Smac, followed by cell death. Complete elucidation of the mechanism of Abeta-induced apoptosis promises to accelerate development of neuroprotective interventions for the treatment of AD.


Assuntos
Peptídeos beta-Amiloides/fisiologia , Apoptose/fisiologia , Proteínas de Transporte/fisiologia , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Proteínas Mitocondriais/fisiologia , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Proteínas/fisiologia , Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/farmacologia , Animais , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Proteína 11 Semelhante a Bcl-2 , Proteínas de Transporte/biossíntese , Proteínas de Transporte/genética , Células Cultivadas/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Regulação para Baixo , Ativação Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Genes bcl-2 , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Neurônios/citologia , Neurônios/metabolismo , Oligopeptídeos/farmacologia , Proteínas/genética , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Interferente Pequeno/fisiologia , Ratos , Ratos Sprague-Dawley , Proteína bcl-X
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