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1.
J Neuroendocrinol ; 32(10): e12904, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33000549

RESUMEN

Neural progestin receptors (PR) function in reproduction, neural development, neuroprotection, learning, memory and the anxiety response. In the absence of progestins, PR can be activated by dopamine (DA) in the rodent hypothalamus to elicit female sexual behaviour. The present study investigated mechanisms of DA activation of PR by testing the hypothesis that proteins from DA-treated hypothalami interact with PR in the absence of progestins. Ovariectomised, oestradiol-primed mice were infused with a D1-receptor agonist, SKF38393 (SKF), into the third ventricle 30 minutes prior to death. Proteins from SKF-treated hypothalami were pulled-down with glutathione S-transferase-tagged mouse PR-A or PR-B and the interactomes were analysed by mass spectrometry. The largest functional group to interact with PR-A in a DA-dependent manner was synaptic proteins. To test the hypothesis that DA activation of PR regulates synaptic proteins, we developed oestradiol-induced PR-expressing hypothalamic-like neurones derived from human-induced pluripotent stem cells (hiPSCs). Similar to progesterone (P4), SKF treatment of hiPSCs increased synapsin1/2 expression. This SKF-dependent effect was blocked by the PR antagonist RU486, suggesting that PR are necessary for this DA-induced increase. The second largest DA-dependent PR-A protein interactome comprised metabolic regulators involved in glucose metabolism, lipid synthesis and mitochondrial energy production. Interestingly, hypothalamic proteins interacted with PR-A, but not PR-B, in an SKF-dependent manner, suggesting that DA promotes the interaction of multiple hypothalamic proteins with PR-A. These in vivo and in vitro results indicate novel mechanisms by which DA can differentially activate PR isoforms in the absence of P4 and provide a better understanding of ligand-independent PR activation in reproductive, metabolic and mental health disorders in women.


Asunto(s)
Dopamina/farmacología , Proteínas del Tejido Nervioso/metabolismo , Receptores de Progesterona/metabolismo , Animales , Femenino , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Progesterona/farmacología , Unión Proteica/efectos de los fármacos , Isoformas de Proteínas/efectos de los fármacos , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
2.
Front Aging Neurosci ; 11: 38, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30930764

RESUMEN

A major aspect of mammalian aging is the decline in functional competence of many self-renewing cell types, including adult-born neuronal precursors in a process termed neurogenesis. Adult neurogenesis is limited to specific brain regions in the mammalian brain, such as the subgranular zone (SGZ) of the hippocampus. Alterations in adult neurogenesis appear to be a common hallmark in different neurodegenerative diseases including Alzheimer's disease (AD). We and others have shown that PPARγ agonism improves cognition in preclinical models of AD as well as in several pilot clinical trials. Context discrimination is recognized as a cognitive task supported by proliferation and differentiation of adult-born neurons in the dentate gyrus of the hippocampus that we and others have previously shown declines with age. We therefore postulated that PPARγ agonism would positively impact context discrimination in middle-aged mice via mechanisms that influence proliferation and differentiation of adult-born neurons arising from the SGZ. To achieve our objective, 8-months old mice were left untreated or treated with the FDA-approved PPARγ agonist, rosiglitazone then tested for context discrimination learning and memory, followed by immunofluorescence evaluation of hippocampal SGZ cell proliferation and neuron survival. We found that PPARγ agonism enhanced context discrimination performance in middle-aged mice concomitant with stimulated SGZ cell proliferation, but not new neuron survival. Focal cranial irradiation that destroys neurogenesis severely compromised context discrimination in middle-aged mice yet rosiglitazone treatment significantly improved cognitive performance through an anti-inflammatory mechanism and resurrection of the neurogenic niche. Thus, we have evidence for divergent mechanisms by which PPARγ agonism impinges upon aging-related versus cranial irradiation-induced deficits in context discrimination learning and memory.

3.
Int J Mol Sci ; 20(4)2019 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-30813227

RESUMEN

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor highly expressed in hepatocytes. Researchers have employed global and liver-specific conditional Ahr knockout mouse models to characterize the physiological roles of the AHR; however, the gestational timing of AHR loss in these models can complicate efforts to distinguish the direct and indirect effects of post-gestational AHR deficiency. Utilizing a novel tamoxifen-inducible AHR knockout mouse model, we analyzed the effects of hepatocyte-targeted AHR loss in adult mice. The data demonstrate that AHR deficiency significantly reduces weight gain and adiposity, and increases multilocular lipid droplet formation within perigonadal white adipose tissue (gWAT). Protein and mRNA expression of fibroblast growth factor 21 (FGF21), an important hepatokine that activates thermogenesis in brown adipose tissue (BAT) and gWAT, significantly increases upon AHR loss and correlates with a significant increase of BAT and gWAT respiratory capacity. Confirming the role of FGF21 in mediating these effects, this phenotype is reversed in mice concomitantly lacking AHR and FGF21 expression. Chromatin immunoprecipitation analyses suggest that the AHR may constitutively suppress Fgf21 transcription through binding to a newly identified xenobiotic response element within the Fgf21 promoter. The data demonstrate an important AHR-FGF21 regulatory axis that influences adipose biology and may represent a "druggable" therapeutic target for obesity and its related metabolic disorders.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Respiración de la Célula , Factores de Crecimiento de Fibroblastos/metabolismo , Gónadas/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Termogénesis , Tejido Adiposo Blanco/efectos de los fármacos , Adiposidad/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Respiración de la Célula/efectos de los fármacos , Dieta Alta en Grasa , Ingestión de Líquidos , Metabolismo Energético/efectos de los fármacos , Conducta Alimentaria/efectos de los fármacos , Femenino , Factores de Crecimiento de Fibroblastos/genética , Gónadas/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Gotas Lipídicas/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Ratones , Ratones Noqueados , Fenotipo , Condicionamiento Físico Animal , Regiones Promotoras Genéticas/genética , Unión Proteica/efectos de los fármacos , Tamoxifeno/farmacología , Termogénesis/efectos de los fármacos , Transcripción Genética/efectos de los fármacos
4.
J Alzheimers Dis ; 64(s1): S427-S453, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29710715

RESUMEN

Insulin resistance can occur when the body is unable to respond to insulin even in excess. In the brain, insulin manages glucose metabolism in regions such as the hippocampus and plays a key role in directly regulating ERK, a kinase required for the type of memory compromised in early Alzheimer's disease (AD). Human imaging studies show that brain glucose utilization declines with age and is notably impaired in subjects with early AD. Likewise, animal models of AD or insulin resistance, or both, demonstrate that dysfunctional insulin signaling and insulin resistance in the brain have reciprocity with neuroinflammation and aberrant accumulation of amyloid-ß (Aß), pathological hallmarks in AD. As such, the association between brain insulin activity and AD has led to clinical trials testing the efficacy of insulin and insulin-sensitizing drugs to intervene in AD. Based on recent inquiries to ClinicalTrials.gov, we evaluated thirty-three clinical studies related to AD and insulin. The search filtered for interventional clinical trials to test FDA-approved drugs or substances that impinge upon the insulin signaling pathway. Insulin, metformin, and thiazolidinediones were the three main interventions assessed. Overall, these strategies are expected to negate the effects of brain insulin resistance by targeting insulin signaling pathways involved in neuroinflammation, metabolic homeostasis, synaptic functional and structural integrity. The goal of this review is to provide an update on insulin and ERK signaling in relation to memory, its decline in early AD, and provide an overview of clinical trials related to insulin for early AD intervention.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Insulina/metabolismo , Animales , Humanos
6.
Addict Biol ; 23(1): 55-68, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-27862692

RESUMEN

Cocaine use disorder is a chronic relapsing condition characterized by compulsive drug seeking and taking even after prolonged abstinence periods. Subsequent exposure to drug-associated cues can promote intense craving and lead to relapse in abstinent humans and rodent models. The responsiveness to these cocaine-related cues, or 'cue reactivity', can trigger relapse and cocaine-seeking behaviors; cue reactivity is measurable in cocaine-dependent humans as well as rodent models. Cue reactivity is thought to be predictive of cocaine craving and relapse. Here we report that PPARγ agonism during abstinence from cocaine self-administration reduced previously active lever pressing in Sprague Dawley rats during cue-reactivity tests, while administration of the PPARγ antagonist, GW9662, reversed this effect. PPARγ agonism also normalized nuclear ERK activity in the medial prefrontal cortex and hippocampus which was reversed with GW9662. Our results support the utility of PPARγ agonism as a relapse prevention strategy to maintain abstinence in the presence of cocaine-associated cues.


Asunto(s)
Cocaína/administración & dosificación , Inhibidores de Captación de Dopamina/administración & dosificación , Comportamiento de Búsqueda de Drogas/efectos de los fármacos , PPAR gamma/agonistas , PPAR gamma/antagonistas & inhibidores , Pioglitazona/farmacología , Anilidas/farmacología , Animales , Conducta Animal/efectos de los fármacos , Trastornos Relacionados con Cocaína , Ansia/efectos de los fármacos , Señales (Psicología) , Locomoción/efectos de los fármacos , Sistema de Señalización de MAP Quinasas , Ratas , Ratas Sprague-Dawley , Recurrencia , Autoadministración
8.
eNeuro ; 4(5)2017.
Artículo en Inglés | MEDLINE | ID: mdl-28955722

RESUMEN

Progestins bind to the progestin receptor (PR) isoforms, PR-A and PR-B, in brain to influence development, female reproduction, anxiety, and stress. Hormone-activated PRs associate with multiple proteins to form functional complexes. In the present study, proteins from female mouse hypothalamus that associate with PR were isolated using affinity pull-down assays with glutathione S-transferase-tagged mouse PR-A and PR-B. Using complementary proteomics approaches, reverse phase protein array (RPPA) and mass spectrometry, we identified hypothalamic proteins that interact with PR in a ligand-dependent and isoform-specific manner and were confirmed by Western blot. Synaptic proteins, including synapsin-I and synapsin-II, interacted with agonist-bound PR isoforms, suggesting that both isoforms function in synaptic plasticity. In further support, synaptogyrin-III and synapsin-III associated with PR-A and PR-B, respectively. PR also interacted with kinases, including c-Src, mTOR, and MAPK1, confirming phosphorylation as an integral process in rapid effects of PR in the brain. Consistent with a role in transcriptional regulation, PR associated with transcription factors and coactivators in a ligand-specific and isoform-dependent manner. Interestingly, both PR isoforms associated with a key regulator of energy homeostasis, FoxO1, suggesting a novel role for PR in energy metabolism. Because many identified proteins in this PR interactome are synaptic proteins, we tested the hypothesis that progestins function in synaptic plasticity. Indeed, progesterone enhanced synaptic density, by increasing synapsin-I-positive synapses, in rat primary cortical neuronal cultures. This novel combination of RPPA and mass spectrometry allowed identification of PR action in synaptic remodeling and energy homeostasis and reveals unique roles for progestins in brain function and disease.


Asunto(s)
Hipotálamo/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Receptores de Progesterona/metabolismo , Sinapsis/metabolismo , Animales , Células Cultivadas , Corteza Cerebral/citología , Embrión de Mamíferos , Estradiol/farmacología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Glutatión Transferasa/metabolismo , Ligandos , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Ovariectomía , Unión Proteica , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Transcripción Genética
9.
Neurobiol Aging ; 58: 1-13, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28688899

RESUMEN

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide. While the causes of AD are not known, several risk factors have been identified. Among these, type two diabetes (T2D), a chronic metabolic disease, is one of the most prevalent risk factors for AD. Insulin resistance, which is associated with T2D, is defined as diminished or absent insulin signaling and is reflected by peripheral blood hyperglycemia and impaired glucose clearance. In this study, we used complementary approaches to probe for peripheral insulin resistance, central nervous system (CNS) insulin sensitivity and energy homeostasis in Tg2576 and 3xTg-AD mice, two widely used animal models of AD. We report that CNS insulin signaling abnormalities are evident months before peripheral insulin resistance. In addition, we find that brain energy metabolism is differentially altered in both mouse models, with 3xTg-AD mice showing more extensive changes. Collectively, our data suggest that early AD may reflect engagement of different signaling networks that influence CNS metabolism, which in turn may alter peripheral insulin signaling.


Asunto(s)
Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/metabolismo , Sistema Nervioso Central/metabolismo , Metabolismo Energético/fisiología , Homeostasis/fisiología , Resistencia a la Insulina , Insulina/metabolismo , Envejecimiento/metabolismo , Animales , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animales de Enfermedad , Femenino , Glucosa/metabolismo , Hiperglucemia/metabolismo , Masculino , Ratones Transgénicos , Factores de Riesgo , Transducción de Señal/fisiología
10.
Exp Neurol ; 295: 1-17, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28522250

RESUMEN

BACKGROUND: Cognitive impairment in humans with Alzheimer's disease (AD) and in animal models of Aß-pathology can be ameliorated by treatments with the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPARγ) agonists, such as rosiglitazone (RSG). Previously, we demonstrated that in the Tg2576 animal model of AD, RSG treatment rescued cognitive deficits and reduced aberrant activity of granule neurons in the dentate gyrus (DG), an area critical for memory formation. METHODS: We used a combination of mass spectrometry, confocal imaging, electrophysiology and split-luciferase assay and in vitro phosphorylation and Ingenuity Pathway Analysis. RESULTS: Using an unbiased, quantitative nano-LC-MS/MS screening, we searched for potential molecular targets of the RSG-dependent rescue of DG granule neurons. We found that S226 phosphorylation of fibroblast growth factor 14 (FGF14), an accessory protein of the voltage-gated Na+ (Nav) channels required for neuronal firing, was reduced in Tg2576 mice upon treatment with RSG. Using confocal microscopy, we confirmed that the Tg2576 condition decreased PanNav channels at the AIS of the DG, and that RSG treatment of Tg2576 mice reversed the reduction in PanNav channels. Analysis from previously published data sets identified correlative changes in action potential kinetics in RSG-treated T2576 compared to untreated and wildtype controls. In vitro phosphorylation and mass spectrometry confirmed that the multifunctional kinase GSK-3ß, a downstream target of insulin signaling highly implicated in AD, phosphorylated FGF14 at S226. Assembly of the FGF14:Nav1.6 channel complex and functional regulation of Nav1.6-mediated currents by FGF14 was impaired by a phosphosilent S226A mutation. Bioinformatics pathway analysis of mass spectrometry and biochemistry data revealed a highly interconnected network encompassing PPARγ, FGF14, SCN8A (Nav 1.6), and the kinases GSK-3 ß, casein kinase 2ß, and ERK1/2. CONCLUSIONS: These results identify FGF14 as a potential PPARγ-sensitive target controlling Aß-induced dysfunctions of neuronal activity in the DG underlying memory loss in early AD.


Asunto(s)
Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Factores de Crecimiento de Fibroblastos/efectos de los fármacos , PPAR gamma/agonistas , Secuencia de Aminoácidos , Animales , Axones/metabolismo , Giro Dentado/metabolismo , Femenino , Factores de Crecimiento de Fibroblastos/genética , Células HEK293 , Humanos , Resistencia a la Insulina , Masculino , Ratones , Ratones Noqueados , Mutación/genética , Fosforilación , Rosiglitazona , Canales de Sodio/genética , Canales de Sodio/metabolismo , Tiazolidinedionas/farmacología
11.
J Neurophysiol ; 113(6): 1712-26, 2015 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-25540218

RESUMEN

Early cognitive impairment in Alzheimer's disease (AD) correlates with medial temporal lobe dysfunction, including two areas essential for memory formation: the entorhinal cortex and dentate gyrus (DG). In the Tg2576 animal model for AD amyloidosis, activation of the peroxisome proliferator-activated receptor-gamma (PPARγ) with rosiglitazone (RSG) ameliorates hippocampus-dependent cognitive impairment and restores aberrant synaptic activity at the entorhinal cortex to DG granule neuron inputs. It is unknown, however, whether intrinsic firing properties of DG granule neurons in these animals are affected by amyloid-ß pathology and if they are sensitive to RSG treatment. Here, we report that granule neurons from 9-mo-old wild-type and Tg2576 animals can be segregated into two cell types with distinct firing properties and input resistance that correlate with less mature type I and more mature type II neurons. The DG type I cell population was greater than type II in wild-type littermates. In the Tg2576 animals, the type I and type II cell populations were nearly equal but could be restored to wild-type levels through cognitive enhancement with RSG. Furthermore, Tg2576 cell firing frequency and spike after depolarization were decreased in type I and increased in type II cells, both of which could also be restored to wild-type levels upon RSG treatment. That these parameters were restored by PPARγ activation emphasizes the therapeutic value of RSG against early AD cognitive impairment.


Asunto(s)
Potenciales de Acción , Enfermedad de Alzheimer/metabolismo , Neuronas/fisiología , PPAR gamma/metabolismo , Enfermedad de Alzheimer/fisiopatología , Animales , Cognición , Corteza Entorrinal/citología , Corteza Entorrinal/efectos de los fármacos , Corteza Entorrinal/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , PPAR gamma/agonistas , Rosiglitazona , Tiazolidinedionas/farmacología
12.
Neurobiol Dis ; 72 Pt A: 92-103, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25237037

RESUMEN

Insulin is a key hormone regulating metabolism. Insulin binding to cell surface insulin receptors engages many signaling intermediates operating in parallel and in series to control glucose, energy, and lipids while also regulating mitogenesis and development. Perturbations in the function of any of these intermediates, which occur in a variety of diseases, cause reduced sensitivity to insulin and insulin resistance with consequent metabolic dysfunction. Chronic inflammation ensues which exacerbates compromised metabolic homeostasis. Since insulin has a key role in learning and memory as well as directly regulating ERK, a kinase required for the type of learning and memory compromised in early Alzheimer's disease (AD), insulin resistance has been identified as a major risk factor for the onset of AD. Animal models of AD or insulin resistance or both demonstrate that AD pathology and impaired insulin signaling form a reciprocal relationship. Of note are human and animal model studies geared toward improving insulin resistance that have led to the identification of the nuclear receptor and transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) as an intervention tool for early AD. Strategic targeting of alternate nodes within the insulin signaling network has revealed disease-stage therapeutic windows in animal models that coalesce with previous and ongoing clinical trial approaches. Thus, exploiting the connection between insulin resistance and AD provides powerful opportunities to delineate therapeutic interventions that slow or block the pathogenesis of AD.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Resistencia a la Insulina , Insulina/metabolismo , Péptidos beta-Amiloides/metabolismo , Animales , Modelos Animales de Enfermedad , Encefalitis/metabolismo , Humanos , Aprendizaje/fisiología , Sistema de Señalización de MAP Quinasas , PPAR gamma/metabolismo
13.
J Neurosci ; 34(11): 4054-63, 2014 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-24623782

RESUMEN

Cognitive impairment is a quintessential feature of Alzheimer's disease (AD) and AD mouse models. The peroxisome proliferator-activated receptor-γ (PPARγ) agonist rosiglitazone improves hippocampus-dependent cognitive deficits in some AD patients and ameliorates deficits in the Tg2576 mouse model for AD amyloidosis. Tg2576 cognitive enhancement occurs through the induction of a gene and protein expression profile reflecting convergence of the PPARγ signaling axis and the extracellular signal-regulated protein kinase (ERK) cascade, a critical mediator of memory consolidation. We therefore tested whether PPARγ and ERK associated in protein complexes that subserve cognitive enhancement through PPARγ agonism. Coimmunoprecipitation of hippocampal extracts revealed that PPARγ and activated, phosphorylated ERK (pERK) associated in Tg2576 in vivo, and that PPARγ agonism facilitated recruitment of PPARγ to pERK during memory consolidation. Furthermore, the amount of PPARγ recruited to pERK correlated with the cognitive reserve in humans with AD and in Tg2576. Our findings implicate a previously unidentified PPARγ-pERK complex that provides a molecular mechanism for the convergence of these pathways during cognitive enhancement, thereby offering new targets for therapeutic development in AD.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Cognición/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Memoria/fisiología , PPAR gamma/metabolismo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/fisiopatología , Anilidas/farmacología , Animales , Cognición/efectos de los fármacos , Femenino , Hipocampo/fisiología , Humanos , Inyecciones Intraventriculares , Masculino , Ratones , Ratones Endogámicos , Ratones Transgénicos , Persona de Mediana Edad , Nootrópicos/farmacología , PPAR gamma/antagonistas & inhibidores , Fosforilación/fisiología , Rosiglitazona , Tiazolidinedionas/farmacología
14.
J Neurosci ; 34(3): 1028-36, 2014 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-24431460

RESUMEN

Hippocampal network hyperexcitability is considered an early indicator of Alzheimer's disease (AD) memory impairment. Some AD mouse models exhibit similar network phenotypes. In this study we focused on dentate gyrus (DG) granule cell spontaneous and evoked properties in 9-month-old Tg2576 mice that model AD amyloidosis and cognitive deficits. Using whole-cell patch-clamp recordings, we found that Tg2576 DG granule cells exhibited spontaneous EPSCs that were higher in frequency but not amplitude compared with wild-type mice, suggesting hyperactivity of DG granule cells via a presynaptic mechanism. Further support of a presynaptic mechanism was revealed by increased I-O relationships and probability of release in Tg2576 DG granule cells. Since we and others have shown that activation of the peroxisome proliferator-activated receptor gamma (PPARγ) axis improves hippocampal cognition in mouse models for AD as well as benefitting memory performance in some humans with early AD, we investigated how PPARγ agonism affected synaptic activity in Tg2576 DG. We found that PPARγ agonism normalized the I-O relationship of evoked EPSCs, frequency of spontaneous EPSCs, and probability of release that, in turn, correlated with selective expression of DG proteins essential for presynaptic SNARE function that are altered in patients with AD. These findings provide evidence that DG principal cells may contribute to early AD hippocampal network hyperexcitability via a presynaptic mechanism, and that hippocampal cognitive enhancement via PPARγ activation occurs through regulation of presynaptic vesicular proteins critical for proper glutamatergic neurotransmitter release, synaptic transmission, and short-term plasticity.


Asunto(s)
Giro Dentado/fisiología , Nootrópicos/farmacología , PPAR gamma/agonistas , PPAR gamma/fisiología , Terminales Presinápticos/fisiología , Tiazolidinedionas/farmacología , Precursor de Proteína beta-Amiloide/genética , Animales , Giro Dentado/efectos de los fármacos , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Técnicas de Cultivo de Órganos , Terminales Presinápticos/efectos de los fármacos , Mapas de Interacción de Proteínas/efectos de los fármacos , Mapas de Interacción de Proteínas/fisiología , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/fisiología , Rosiglitazona
15.
Mol Cell Proteomics ; 12(12): 3640-52, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24008390

RESUMEN

Chronic hepatic disease damages the liver, and the resulting wound-healing process leads to liver fibrosis and the subsequent development of cirrhosis. The leading cause of hepatic fibrosis and cirrhosis is infection with hepatitis C virus (HCV), and of the patients with HCV-induced cirrhosis, 2% to 5% develop hepatocellular carcinoma (HCC), with a survival rate of 7%. HCC is one of the leading causes of cancer-related death worldwide, and the poor survival rate is largely due to late-stage diagnosis, which makes successful intervention difficult, if not impossible. The lack of sensitive and specific diagnostic tools and the urgent need for early-stage diagnosis prompted us to discover new candidate biomarkers for HCV and HCC. We used aptamer-based fractionation technology to reduce serum complexity, differentially labeled samples (six HCV and six HCC) with fluorescent dyes, and resolved proteins in pairwise two-dimensional difference gel electrophoresis. DeCyder software was used to identify differentially expressed proteins and spots picked, and MALDI-MS/MS was used to determine that ApoA1 was down-regulated by 22% (p < 0.004) in HCC relative to HCV. Differential expression quantified via two-dimensional difference gel electrophoresis was confirmed by means of (18)O/(16)O stable isotope differential labeling with LC-MS/MS zoom scans. Technically independent confirmation was demonstrated by triple quadrupole LC-MS/MS selected reaction monitoring (SRM) assays with three peptides specific to human ApoA1 (DLATVYVDVLK, WQEEMELYR, and VSFLSALEEYTK) using (18)O/(16)O-labeled samples and further verified with AQUA peptides as internal standards for quantification. In 50 patient samples (24 HCV and 26 HCC), all three SRM assays yielded highly similar differential expression of ApoA1 in HCC and HCV patients. These results validated the SRM assays, which were independently confirmed by Western blotting. Thus, ApoA1 is a candidate member of an SRM biomarker panel for early diagnosis, prognosis, and monitoring of HCC. Future multiplexing of SRM assays for other candidate biomarkers is envisioned to develop a biomarker panel for subsequent verification and validation studies.


Asunto(s)
Apolipoproteína A-I/genética , Biomarcadores de Tumor/genética , Carcinoma Hepatocelular/genética , Regulación Neoplásica de la Expresión Génica , Hepatitis C Crónica/genética , Cirrosis Hepática/genética , Neoplasias Hepáticas/genética , Adulto , Secuencia de Aminoácidos , Apolipoproteína A-I/sangre , Aptámeros de Péptidos/química , Biomarcadores de Tumor/sangre , Carcinoma Hepatocelular/sangre , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/etiología , Diagnóstico Precoz , Electroforesis en Gel Bidimensional , Colorantes Fluorescentes/química , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/sangre , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/diagnóstico , Humanos , Marcaje Isotópico , Cirrosis Hepática/sangre , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/etiología , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/etiología , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Isótopos de Oxígeno , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
16.
J Neurotrauma ; 30(9): 775-88, 2013 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-22757692

RESUMEN

Traumatic brain injury (TBI) is a complex and common problem resulting in the loss of cognitive function. In order to build a comprehensive knowledge base of the proteins that underlie these cognitive deficits, we employed unbiased quantitative mass spectrometry, proteomics, and bioinformatics to identify and quantify dysregulated proteins in the CA3 subregion of the hippocampus in the fluid percussion model of TBI in rats. Using stable isotope 18O-water differential labeling and multidimensional tandem liquid chromatography (LC)-MS/MS with high stringency statistical analyses and filtering, we identified and quantified 1002 common proteins, with 124 increased and 76 decreased. The ingenuity pathway analysis (IPA) bioinformatics tool identified that TBI had profound effects on downregulating global energy metabolism, including glycolysis, the Krebs cycle, and oxidative phosphorylation, as well as cellular structure and function. Widespread upregulation of actin-related cytoskeletal dynamics was also found. IPA indicated a common integrative signaling node, calcineurin B1 (CANB1, CaNBα, or PPP3R1), which was downregulated by TBI. Western blotting confirmed that the calcineurin regulatory subunit, CANB1, and its catalytic binding partner PP2BA, were decreased without changes in other calcineurin subunits. CANB1 plays a critical role in downregulated networks of calcium signaling and homeostasis through calmodulin and calmodulin-dependent kinase II to highly interconnected structural networks dominated by tubulins. This large-scale knowledge base lays the foundation for the identification of novel therapeutic targets for cognitive rescue in TBI.


Asunto(s)
Lesiones Encefálicas/fisiopatología , Calcineurina/metabolismo , Hipocampo/fisiopatología , Proteómica/métodos , Animales , Western Blotting , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/patología , Cromatografía Liquida , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Hipocampo/patología , Masculino , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en Tándem
17.
J Neurosci ; 32(47): 16725-35a, 2012 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-23175826

RESUMEN

We previously reported that the peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone (RSG) improved hippocampus-dependent cognition in the Alzheimer's disease (AD) mouse model, Tg2576. RSG had no effect on wild-type littermate cognitive performance. Since extracellular signal-regulated protein kinase mitogen-activated protein kinase (ERK MAPK) is required for many forms of learning and memory that are affected in AD, and since both PPARγ and ERK MAPK are key mediators of insulin signaling, the current study tested the hypothesis that RSG-mediated cognitive improvement induces a hippocampal PPARγ pattern of gene and protein expression that converges with the ERK MAPK signaling axis in Tg2576 AD mice. In the hippocampal PPARγ transcriptome, we found significant overlap between peroxisome proliferator response element-containing PPARγ target genes and ERK-regulated, cAMP response element-containing target genes. Within the Tg2576 dentate gyrus proteome, RSG induced proteins with structural, energy, biosynthesis and plasticity functions. Several of these proteins are known to be important for cognitive function and are also regulated by ERK MAPK. In addition, we found the RSG-mediated augmentation of PPARγ and ERK2 activity during Tg2576 cognitive enhancement was reversed when hippocampal PPARγ was pharmacologically antagonized, revealing a coordinate relationship between PPARγ transcriptional competency and phosphorylated ERK that is reciprocally affected in response to chronic activation, compared with acute inhibition, of PPARγ. We conclude that the hippocampal transcriptome and proteome induced by cognitive enhancement with RSG harnesses a dysregulated ERK MAPK signal transduction pathway to overcome AD-like cognitive deficits in Tg2576 mice. Thus, PPARγ represents a signaling system that is not crucial for normal cognition yet can intercede to restore neural networks compromised by AD.


Asunto(s)
Hipocampo/fisiología , Sistema de Señalización de MAP Quinasas/fisiología , Nootrópicos/farmacología , PPAR gamma/fisiología , Transducción de Señal/fisiología , Tiazolidinedionas/farmacología , Péptidos beta-Amiloides/metabolismo , Animales , Western Blotting , Núcleo Celular/fisiología , Condicionamiento Psicológico , Electrochoque , Miedo , Femenino , Inyecciones Intraventriculares , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , PPAR gamma/antagonistas & inhibidores , Reacción en Cadena de la Polimerasa , Rosiglitazona , Espectrometría de Masas en Tándem , Transcriptoma/fisiología
18.
J Neurotrauma ; 29(2): 295-312, 2012 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-22077363

RESUMEN

Transplantation of neural stem cells (NSCs) improves functional outcomes following traumatic brain injury (TBI). Previously we demonstrated that human NSCs (hNSCs) via releasing glial cell line-derived neurotrophic factor (GDNF), preserved cognitive function in rats following parasagittal fluid percussion. However, the underlying mechanisms remain elusive. In this study, we report that NSC grafts significantly reduce TBI-induced axonal injury in the fimbria and other brain regions by blocking abnormal accumulation of amyloid precursor protein (APP). A preliminary mass spectrometry proteomics study revealed the opposite effects of TBI and NSCs on many of the cytoskeletal proteins in the CA3 region of the hippocampus, including α-smooth muscle actin (α-SMA), the main stress fiber component. Further, Western blot and immunostaining studies confirmed that TBI significantly increased the expression of α-SMA in hippocampal neurons, whereas NSC grafts counteracted the effect of TBI. In an in vitro model, rapid stretch injury significantly shortened lengths of axons and dendrites, increased the expression of both APP and α-SMA, and induced actin aggregation, effects offset by GDNF treatment. These GDNF protective effects were reversed by a GDNF-neutralizing antibody or a specific calcineurin inhibitor, and were mimicked by a specific Rho inhibitor. In summary, we demonstrate for the first time that hNSC grafts and treatment with GDNF acutely reduce traumatic axonal injury and promote neurite outgrowth. Possible mechanisms underlying GDNF-mediated neurite protection include balancing the activity of calcineurin, whereas GDNF-induced neurite outgrowth may result from the reduction of the abnormal α-SMA expression and actin aggregation via blocking Rho signals. Our study also suggests the necessity of further exploring the roles of α-SMA in the central nervous system (CNS), which may lead to a new avenue to facilitate recovery after TBI and other injuries.


Asunto(s)
Lesión Axonal Difusa/patología , Lesión Axonal Difusa/fisiopatología , Factor Neurotrófico Derivado de la Línea Celular Glial/fisiología , Células-Madre Neurales/fisiología , Células-Madre Neurales/trasplante , Recuperación de la Función/fisiología , Animales , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/patología , Lesiones Encefálicas/fisiopatología , Línea Celular , Células Cultivadas , Lesión Axonal Difusa/metabolismo , Factor Neurotrófico Derivado de la Línea Celular Glial/administración & dosificación , Factor Neurotrófico Derivado de la Línea Celular Glial/uso terapéutico , Humanos , Masculino , Células-Madre Neurales/citología , Ratas , Ratas Sprague-Dawley
19.
Behav Brain Res ; 216(1): 255-61, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-20709114

RESUMEN

Converging lines of evidence associate gluco-regulatory abnormalities and peroxisome-proliferator-activated receptor (PPAR) gamma function with increased risk for Alzheimer's disease (AD). In this study, we used the Tg2576 AD mouse model to test the hypothesis that cognitive improvement following 1 month of PPAR gamma agonism with rosiglitazone (RTZ) correlates with peripheral gluco-regulatory status. We assessed cognition and peripheral gluco-regulatory status of Tg2576 mice following 1 month treatment with RTZ initiated prior to, coincident with, or after, the onset of peripheral gluco-regulatory abnormalities (4, 8, and 12 months of age, respectively). Whereas 5 months old (MO) and 13 MO Tg2576 did not gain cognitive improvement after 1 month treatment with RTZ, 9 MO Tg2576 mice exhibited reversal of associative learning and memory deficits. Peripheral gluco-regulatory abnormalities were improved in 9 and 13 MO Tg2576 with RTZ treatment; RTZ treatment had no effect on the normal glucose status of 5 MO Tg2576 mice. These findings suggest that RTZ-mediated cognitive improvement does not correlate with peripheral gluco-regulatory abnormalities per se, but reflects the age-dependent mechanistic differences that underlie cognitive decline in this mouse model.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Aprendizaje por Asociación/efectos de los fármacos , Glucemia/metabolismo , Cognición/efectos de los fármacos , Memoria/efectos de los fármacos , Tiazolidinedionas/uso terapéutico , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Análisis de Varianza , Animales , Área Bajo la Curva , Modelos Animales de Enfermedad , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Hipoglucemiantes/uso terapéutico , Insulina/sangre , Ratones , Ratones Transgénicos , Rosiglitazona
20.
Int J Psychiatry Med ; 40(3): 289-305, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21166339

RESUMEN

OBJECTIVE: The aim of this study was to investigate the association between psychosocial variables, biomarker hemoglobin A1C (HbA1C), and immune modulatory cytokine mediators among diabetic patients in marital or committed long-term relationships. METHOD: This is a cross-sectional study of adult patients with Type 2 diabetes mellitus (T2DM) presenting at a university-based ambulatory medical clinic. Social/interpersonal constructs were assessed using measures of dyadic adjustment, interpersonal sensitivity and social functioning, and expressed emotion. HbA1c and cytokines were measured from blood samples using standard laboratory tests. Associations of relational systems constructs with biomarkers were assessed using bivariate tests. RESULTS: Dyadic adjustment was significantly associated with cytokine IL-8. Interpersonal relationship functioning was significantly associated with biomarker HbA1c, and cytokines TNF-alpha, and IL-1ra. Social functioning was significantly correlated with cytokines IL-17, IL-1ra, IL-2r, IL-6, and eotaxin. Depression was significantly correlated with HbA1C. CONCLUSIONS: Although preliminary in nature, findings revealed significant relationships between molecular mediators of the inflammatory and immune systems and variables measuring the relational context patients with T2DM. The initial findings suggest a next step in understanding and exploring the complex but important biopsychosocial pathways in Type 2 DM.


Asunto(s)
Citocinas/sangre , Diabetes Mellitus Tipo 2/psicología , Conflicto Familiar/psicología , Mediadores de Inflamación/sangre , Inflamación/psicología , Medio Social , Adulto , Anciano , Trastorno Depresivo/inmunología , Trastorno Depresivo/psicología , Diabetes Mellitus Tipo 2/inmunología , Emoción Expresada , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Inflamación/inmunología , Interleucina-8/sangre , Masculino , Persona de Mediana Edad , Inventario de Personalidad/estadística & datos numéricos , Psicometría , Autoeficacia , Estadística como Asunto
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