RESUMEN
Environmental enrichment induces behavioral and structural modifications in rodents and influences the capability of mice to cope with stress. However, little is understood about hippocampal neurogenesis and the appearance of social/agonistic (aggressive) behavior upon activation of different neuronal circuits in FVB/N mice. Thus, in this study we hypothesized that environmental enrichment differentially regulates neurogenesis, neural circuit activation and social/agonistic behavior in male and female FVB/N mice. We explored the (1) neurogenic process as an indicative of neuroplasticity, (2) neuronal activation in the limbic system, and (3) social behavior using the resident-intruder test. On postnatal day 23 (PD23), mice were assigned to one of two groups: Standard Housing or Environmental Enrichment. At PD53, rodents underwent the resident-intruder test to evaluate social behaviors. Results revealed that environmental enrichment increased neurogenesis and social interaction in females. In males, environmental enrichment increased neurogenesis and agonistic behavior. Enriched male mice expressed higher levels of agonistic-related behavior than female mice housed under the same conditions. Neural circuit analysis showed lower activation in the amygdala of enriched males and higher activation in enriched females than their respective controls. Enriched females also showed higher activation in the frontal cortex without differences in male groups. Moreover, the insular cortex was less activated in females than in males. Thus, our results indicate that environmental enrichment has different effects on neuroplasticity and social/agonistic behavior in FVB/N mice, suggesting the relevance of sexual dimorphism in response to environmental stimuli.
Asunto(s)
Conducta Agonística , Interacción Social , Agresión/fisiología , Conducta Agonística/fisiología , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos , Conducta SocialRESUMEN
Depression is a neuropsychiatric disorder with a high impact on the worldwide population. To overcome depression, antidepressant drugs are the first line of treatment. However, pre-clinical studies have pointed out that antidepressants are not entirely efficacious and that the quality of the living environment after stress cessation may play a relevant role in increasing their efficacy. As it is unknown whether a short daily exposure to environmental enrichment during chronic stress and antidepressant treatment will be more effective than just the pharmacological treatment, this study analyzed the effects of fluoxetine, environmental enrichment, and their combination on depressive-associated behavior. Additionally, we investigated hippocampal neurogenesis in mice exposed to chronic mild stress. Our results indicate that fluoxetine reversed anhedonia. Besides, fluoxetine reversed the decrement of some events of the hippocampal neurogenic process caused by chronic mild stress. Conversely, short daily exposure to environmental enrichment changed the deterioration of the coat and anhedonia. Although, this environmental intervention did not produce significant changes in the neurogenic process affected by chronic mild stress, fluoxetine plus environmental enrichment showed similar effects to those caused by environmental enrichment to reverse depressive-like behaviors. Like fluoxetine, the combination reversed the declining number of Ki67, doublecortin, calretinin cells and mature newborn neurons. Finally, this study suggests that short daily exposure to environmental enrichment improves the effects of fluoxetine to reverse the deterioration of the coat and anhedonia in chronically stressed mice. In addition, the combination of fluoxetine with environmental enrichment produces more significant effects than those caused by fluoxetine alone on some events of the neurogenic process. Thus, environmental enrichment improves the benefits of pharmacological treatment by mechanisms that need to be clarified.
Asunto(s)
Anhedonia/efectos de los fármacos , Fluoxetina/farmacología , Hipocampo/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Estrés Psicológico/fisiopatología , Anhedonia/fisiología , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Calbindina 2/metabolismo , Proliferación Celular , Proteína Doblecortina/metabolismo , Ambiente , Femenino , Hipocampo/metabolismo , Hipocampo/patología , Antígeno Ki-67/metabolismo , Ratones , Ratones Endogámicos BALB C , Estrés FisiológicoRESUMEN
Adult neurogenesis occurs in the dentate gyrus (DG) of the hippocampus. New neurons help to counteract the effects of stress and several interventions including antidepressant drugs, environmental modifications and internal factors act pro-neurogenic with consequences in the dorsal and ventral DG. Melatonin, the main product synthesized by the pineal gland, induces antidepressant-like effects and modulates several events of the neurogenic process. However, the information related to the capability of melatonin to modulate dendrite maturation and complexity in the dorsal and ventral regions of the DG and their correlation with its antidepressant-like effect is absent. Thus, in this study, we analyzed the impact of melatonin (0, 0.5, 1, 2.5, 5 or 10 mg/kg) administered daily for fourteen days on the number, dendrite complexity and distribution of doublecortin (DCX)-cells in the dorsal-ventral regions of the DG in male Balb/C mice. Doublecortin is a microtubule-associated protein that is expressed during the course of dendritic maturation of newborn neurons. Also, we analyzed the impact of melatonin on despair-like behavior in the forced swim test. We first found a significant increase in the number and higher dendrite complexity, mainly with the doses of 2.5, 5 and 10 mg/kg of melatonin (81%, 122%, 78%). These cells showed more complex dendritic trees in the ventral- and the dorsal- DG. Concomitantly, the doses of 5 and 10 mg/kg of melatonin decreased depressant-like behavior (76%, 82%). Finally, the data corroborate the antidepressant-like effect of melatonin and the increasing number of doublecortin-associated cells. Besides, the data indicate that melatonin favors the number and dendrite complexity of DCX-cells in the dorsal- and ventral- region of the DG, which may explain part of the antidepressant-like effect of melatonin.
Asunto(s)
Antidepresivos/uso terapéutico , Dendritas/efectos de los fármacos , Dendritas/metabolismo , Giro Dentado/efectos de los fármacos , Giro Dentado/metabolismo , Melatonina/uso terapéutico , Animales , Depresión/tratamiento farmacológico , Depresión/metabolismo , Proteínas de Dominio Doblecortina , Proteína Doblecortina , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos BALB C , Proteínas Asociadas a Microtúbulos/metabolismo , Neurogénesis/efectos de los fármacos , Neuropéptidos/metabolismoRESUMEN
Neurogenesis in the hippocampus is influenced by several factors including external stimuli. In addition to their involvement in learning and memory processes, newborn neurons of the dentate gyrus (DG) buffer against the effects of stress. Although the response of these cells to environmental stimuli has been shown, the age of the cells that respond to a brief spatial exploration or a stressful situation produced by forced-swim stress in adult female Balb/C mice is still unknown. Here, we investigated the activation of newborn neurons after three (IdU) or six weeks (CldU) postlabelling with the expression of Arc in the same mice but exposed to different environmental stimuli. Mice housed in standard conditions showed an increase in the activation of CldU-labelled cells after two exposures to a brief spatial exploration but no increase in the activation of IdU-labelled cells compared with the control group. Additionally, we analysed neuronal activation in the DG of mice housed in standard conditions and further exposed to forced-swim stress. We found a decreased activation of IdU-labelled cells in mice exposed to forced-swim stress with increase number of CldU-labelled cells. Our results suggest that based on their time postlabelling, newly generated hippocampal neurons show a different response to several environmental stimuli.
Asunto(s)
Giro Dentado/fisiología , Conducta Exploratoria , Neurogénesis , Neuronas/fisiología , Conducta Espacial , Estrés Psicológico , Animales , Proteínas del Citoesqueleto/metabolismo , Giro Dentado/metabolismo , Femenino , Ratones Endogámicos BALB C , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , NataciónRESUMEN
Several interventions have been shown to counteract the effects of stress that may be related to improved neuroplasticity and neuronal activation. In this sense, environmental enrichment (ENR) protects against acute stress and increases neuroplasticity. It has been suggested that the use of patterned auditory stimuli (PAS) may be beneficial in increasing the effectiveness of ENR on disorders related to stress, such as depression and anxiety. Examples of PAS are classical music compositions that have interesting effects at both clinical and preclinical levels. Thus, we analyzed the effects of the exposure to PAS, represented in this study by Mozart's compositions, during ENR housing for 35 days in adult male Balb/C mice to evaluate depression-associated behavior using the forced-swim test (FST) paradigm with an additional short exposure to PAS. We found that the ENR mice that were exposed to PAS during both housing and behavioral task (ENR + PAS/FST + PAS) show decreased immobility and the number of despair episodes within a higher latency to show the first bout of immobility. Additionally, we found increased neuronal activation evaluated by the identification of activity-regulated cytoskeleton-associated protein- (Arc-) labeled cells in the prefrontal cortex (PFC) in mice exposed to PAS during housing and in the absence or presence of PAS during FST. Moreover, we found increased neuronal activation in the auditory cortex (AuCx) of mice exposed to PAS during FST. Our study suggests that the exposure to PAS during an emotional challenge decreases despair-like behavior in rodents that were previously housed in an enriched environment in combination with auditory stimuli. Thus, our data indicate that the role of the exposure to PAS as an intervention or in combination with positive environment to aid in treating neuropsychiatric disorders is worth pursuing.
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Estimulación Acústica/métodos , Depresión , Vivienda para Animales , Estrés Fisiológico/fisiología , Estrés Psicológico/fisiopatología , Animales , Corticosterona/sangre , Ambiente , Masculino , Ratones , Ratones Endogámicos BALB C , Neuronas/fisiología , Estrés Psicológico/psicología , NataciónRESUMEN
Melatonin, the main product synthesized by the pineal gland, acts as a regulator of the generation of new neurons in the dentate gyrus (DG). Newborn neurons buffer the deleterious effects of stress and are involved in learning and memory processes. Furthermore, melatonin, through the regulation of the cytoskeleton, favors dendrite maturation of newborn neurons. Moreover, newborn neurons send their axons via the mossy fiber tract to Cornu Ammonis 3 (CA3) region to form synapses with pyramidal neurons. Thus, axons of newborn cells contribute to the mossy fiber projection and their plasticity correlates with better performance in several behavioral tasks. Thus, in this study, we analyzed the impact of exogenous melatonin (8 mg/kg) administered daily for one- or six-months on the structural plasticity of infrapyramidal- and suprapyramidal mossy fiber projection of granule cells in the DG in male Balb/C mice. We analyzed the mossy fiber projection through the staining of calbindin, that is a calcium-binding protein localized in dendrites and axons. We first found an increase in the number of calbindin-positive cells in the granular cell layer in the DG (11%, 33%) after treatment. Futhermore, we found an increase in the volume of suprapyramidal (>135%, 59%) and infrapyramidal (>128%, 36%) mossy fiber projection of granule neurons in the DG after treatment. We also found an increase in the volume of CA3 region (>146%, 33%) after treatment, suggesting that melatonin modulates the structural plasticity of the mossy fiber projection to establish functional synapses in the hippocampus. Together, the data suggest that, in addition to the previously reported effects of melatonin on the generation of new neurons and its antidepressant like effects, melatonin also modulates the structural plasticity of axons in granule cells in the DG.
Asunto(s)
Axones/metabolismo , Giro Dentado/metabolismo , Melatonina/farmacología , Plasticidad Neuronal/efectos de los fármacos , Animales , Región CA3 Hipocampal/efectos de los fármacos , Región CA3 Hipocampal/fisiología , Calbindinas/metabolismo , Giro Dentado/citología , Masculino , Ratones , Ratones Endogámicos BALB C , Fibras Nerviosas/efectos de los fármacos , Fibras Nerviosas/fisiologíaRESUMEN
Adult hippocampal neurogenesis is affected in some neuropsychiatric disorders such as depression. Numerous evidence indicates that plasma levels of melatonin are decreased in depressed patients. Also, melatonin exerts positive effects on the hippocampal neurogenic process and on depressive-like behavior. In addition, antidepressants revert alterations of hippocampal neurogenesis present in models of depression following a similar time course to the improvement of behavior. In this study, we analyzed the effects of both, citalopram, a widely used antidepressant, and melatonin in the Porsolt forced swim test. In addition, we investigated the potential antidepressant role of the combination of melatonin and citalopram (MLTCITAL), its type of pharmacological interaction on depressive behavior, and its effect on hippocampal neurogenesis. Here, we found decreased immobility behavior in mice treated with melatonin (<14-33%) and citalopram (<17-30%). Additionally, the MLTCITAL combination also decreased immobility (<22-35%) in comparison with control mice, reflecting an antidepressant-like effect after 14 days of treatment. Moreover, MLTCITAL decreased plasma corticosterone levels (≤13%) and increased cell proliferation (>29%), survival (>39%), and the absolute number of -associated new neurons (>53%) in the dentate gyrus of the hippocampus. These results indicate that the MLTCITAL combination exerts synergism to induce an antidepressant-like action that could be related to the modulation of adult hippocampal neurogenesis. This outcome opens the opportunity of using melatonin to promote behavioral benefits and hippocampal neurogenesis in depression and also supports the use of the MLTCITAL combination as an alternative to treat depression.
Asunto(s)
Antidepresivos de Segunda Generación/farmacología , Antioxidantes/farmacología , Conducta Animal/efectos de los fármacos , Citalopram , Depresión , Hipocampo/metabolismo , Melatonina , Neurogénesis/efectos de los fármacos , Animales , Citalopram/agonistas , Citalopram/farmacología , Depresión/tratamiento farmacológico , Depresión/patología , Depresión/fisiopatología , Sinergismo Farmacológico , Hipocampo/patología , Masculino , Melatonina/agonistas , Melatonina/farmacología , Ratones , Ratones Endogámicos BALB CRESUMEN
Several factors, including environmental modifications, stimulate neuroplasticity. One type of neuroplasticity consists in the generation of new neurons in the dentate gyrus of the hippocampus. Neurogenesis is modulated by environmental enrichment (ENR, tunnels plus running wheel) and affected by the time of exposure to ENR. Despite the wide use of ENR to stimulate neuroplasticity, the degree to which ENR variations modeled by temporally changing the level of environmental complexity affect hippocampal neurogenesis and anxiety is still unclear. Thus, we investigated the effects of five housing conditions on young adult male Balb/C mice exposed for 42 days. The groups were as follows: standard conditions without ENR, constant ENR complexity, gradual increase of ENR complexity followed by a gradual decrease of ENR complexity, gradual increase of ENR complexity followed by constant ENR complexity, and constant ENR complexity followed by a gradual decrease of ENR complexity. On day 44, mice were exposed to the elevated plus-maze to evaluate anxiety. Further, we analyzed neurogenesis and quantified corticosterone levels. In an additional experiment, we explored the effect of voluntary physical activity on anxiety, neurogenesis, and corticosterone during the variations in ENR complexity. Our results showed that any change in ENR complexity over time reduced anxiety. Also, voluntary physical activity alone or in the context of a complex environment increased doublecortin cell maturation in the granular cell layer of the hippocampus. Finally, our study supports that physical activity acts proneurogenic, whereas any change in environmental complexity decreases anxiety-like behavior. However, the decrease in corticosterone levels elicited by physical activity was lower than the decrease produced by the decrement in environmental complexity.
Asunto(s)
Corticosterona , Ambiente , Animales , Ansiedad , Hipocampo/fisiología , Masculino , Ratones , Ratones Endogámicos BALB C , Neurogénesis/fisiologíaRESUMEN
In the course of adult hippocampal neurogenesis, the postmitotic maturation and survival phase is associated with dendrite maturation. Melatonin modulates the survival of new neurons with relative specificity. During this phase, the new neurons express microtubule-associated protein doublecortin (DCX). Here, we show that the entire population of cells expressing DCX is increased after 14 days of treatment with melatonin. As melatonin also affects microtubule polymerization which is important for neuritogenesis and dendritogenesis, we studied the consequences of chronic melatonin administration on dendrite maturation of DCX-positive cells. Treatment with melatonin increased the number of DCX-positive immature neurons with more complex dendrites. Sholl analysis revealed that melatonin treatment lead to greater complexity of the dendritic tree. In addition, melatonin increased the total volume of the granular cell layer. Besides its survival-promoting effect, melatonin thus also increases dendritic maturation in adult neurogenesis. This might open the opportunity of using melatonin as an adjuvant in attempts to extrinsically stimulate adult hippocampal neurogenesis in neuropsychiatric disease, dementia or cognitive ageing.
Asunto(s)
Dendritas/efectos de los fármacos , Hipocampo/citología , Hipocampo/efectos de los fármacos , Melatonina/farmacología , Neurogénesis/efectos de los fármacos , Neuronas/citología , Neuronas/efectos de los fármacos , Animales , Antioxidantes/farmacología , Giro Dentado/citología , Giro Dentado/efectos de los fármacos , Proteínas de Dominio Doblecortina , Proteína Doblecortina , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Neuropéptidos/metabolismoRESUMEN
As mammals evolved with exposure to particular diets, naturally abundant compounds may have become part of the set of environmental co-determinants that shaped brain structure and function. Here we investigated whether bioactive factors found in apples directly affect hippocampal neurogenesis in the adult mouse. We found that quercetin, the most abundant flavanol in apple peel, was anti-proliferative at high concentrations but pro-neurogenic at low concentrations. This was confirmed in vivo, with intraperitoneally delivered quercetin promoting survival and neuronal differentiation, without affecting proliferation. Using a bioassay-guided fractionation approach we also identified additional pro-neurogenic compounds in apple flesh that were not related to flavonoids. We found that 3,5-dihydroxybenzoic acid significantly increased neural precursor cell proliferation and neurogenesis. This work shows that both flavonoids and 3,5-dihydroxybenzoic acid are pro-neurogenic, not only by activating precursor cell proliferation but also by promoting cell-cycle exit, cellular survival, and neuronal differentiation.
Asunto(s)
Frutas/química , Hipocampo/efectos de los fármacos , Hidroxibenzoatos/farmacología , Malus/química , Neurogénesis/efectos de los fármacos , Quercetina/farmacología , Resorcinoles/farmacología , Animales , Antioxidantes/farmacología , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Flavonoides/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transducción de SeñalRESUMEN
Depression may be precipitated by the negative impact of chronic stress, which is considered to play a key role in this neuropsychiatric disorder. Interestingly, depressed patients show decreased levels of melatonin. This hormone acts pro-neurogenic and exhibits anti-depressant effects in rodent models of predictive antidepressant-like effects. However, the benefits of melatonin in reversing the deleterious effects of chronic mild stress on the alterations in behaviour and in the neurogenic niche of the hippocampus in male BALB/c mice are unknown. In this study, we compared the effects of melatonin (2.5â¯mg/kg) and citalopram (5â¯mg/kg), an antidepressant drug belonging to the selective serotonin reuptake inhibitors, in male BALB/c mice exposed to chronic mild stress (CMS). We also investigated the potential effects of melatonin and citalopram on microglial cells, hippocampal neurogenesis and peripheral cytokine profiles. Melatonin and citalopram induced similar antidepressant-like activities that occurred with some of the the following findings: (1) reversal of the morphological alterations in microglia; (2) reversal of the decreased immunoreactivity to CX3CL1 and CX3CR1 in the dentate gyrus; (3) positive regulation of cell proliferation, survival and complexity of the dendritic trees of doublecortin-cells; and (4) modifications of peripheral CX3CL1 expression. This outcome is consistent with the hypothesis about the antidepressant-like effect of melatonin and supports its relevance as a modulator of the niche in the dentate gyrus.
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Quimiocina CX3CL1 , Melatonina , Animales , Depresión/tratamiento farmacológico , Hipocampo , Masculino , Melatonina/farmacología , Ratones , Ratones Endogámicos BALB C , Microglía , NeurogénesisRESUMEN
Cell movement is generated by a driving force provided by dynamic cytoskeletal organization. Two main cytoskeletal-dependent features, essential for migration, are the highly cell polarized structure and focal adhesion complexes. Cell migration and substrate anchorage are finely regulated by external signaling exerted by growth factors and hormones. In particular, the serine threonine kinase activated by the small GTPase Rho, the Rho-associated protein kinase (ROCK), participate in both processes through regulation of actin rearrangements in lamellipodia, filopodia, ruffles, and stress fibers. Melatonin, the main product secreted by the pineal gland has oncostatic properties. In MCF-7 cells, 1 nm melatonin reduces migration and invasiveness through increased expression of two cell surface adhesion proteins, E-cadherin and beta(1)-integrin. In this work, we studied the microfilament and microtubule rearrangements elicited by melatonin in migrating leader MCF-7 cells by a wound-healing assay. Additionally, cell anchorage was estimated by quantification of focal adhesions in MCF-7 cells cultured with melatonin. ROCK participation in the indole effects on anchorage and migration was explored by inhibition of the kinase activity with the specific inhibitor of ROCK, the Y-27632 compound. The results indicate that ROCK participates in the melatonin inhibitory effects on cell migration by changing cytoskeletal organization of leader MCF-7 cells. Also, they indicated that indole increased the number of focal contacts through ROCK. These results support the notion that melatonin inhibits cancer cell invasion and metastasis formation via ROCK-regulated microfilament and microtubule organization that converge in a migration/anchorage switch.
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Neoplasias de la Mama/patología , Movimiento Celular/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Melatonina/farmacología , Quinasas Asociadas a rho/metabolismo , Amidas/farmacología , Análisis de Varianza , Animales , Neoplasias de la Mama/enzimología , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Citoesqueleto/fisiología , Humanos , Microscopía Fluorescente , Microtúbulos/efectos de los fármacos , Piridinas/farmacología , Ratas , Cicatrización de Heridas/efectos de los fármacos , Quinasas Asociadas a rho/antagonistas & inhibidoresRESUMEN
Neurogenesis plays a significant role during adulthood, and the observation that neural stem cells reside in the central nervous system and the olfactory epithelium has attracted attention due to their importance in neuronal regeneration. In addition, soluble factors (SFs) release by neural stem cells may modulate the neurogenic process. Thus, in this study, we identified the SFs released by olfactory human neural stem/progenitor cells (hNS/PCs-OE). These cells express Ki67, nestin, and ßIII-tubulin, indicating their neural lineage. The hNS/PCs-OE also express PSD95 and tau proteins during proliferation, but increased levels are observed after differentiation. Thus, we evaluated the effects of SFs from hNS/PCs-OE on the viability, proliferation, and differentiation potential of adult murine hippocampal neural precursor cells (AHPCs). SFs from hNS/PCs-OE maintain cells in the precursor and proliferative stages and mainly promote the astrocytic differentiation of AHPCs. These effects involved the activation, as measured by phosphorylation, of several proteins (Erk1/2; Akt/PRAS40/GSK3ß and JAK/STAT) involved in key events of the neurogenic process. Moreover, according to the results from the antibody-based microarray approach, among the soluble factors, hNS/PCs-OE produce interleukin-6 (IL-6) and neurotrophin 4 (NT4). However, residual epidermal growth factor (EGF) was also detected. These proteins partially reproduced the effects of SFs from hNS/PCs-OE on AHPCs, and the mechanism underlying these effects is mediated by Src proteins, which have been implicated in EGF-induced transactivation of TrkB receptor. The results of the present study suggest the potential use of SFs from hNS/PCs-OE in controlling the differentiation potential of AHPCs. Thus, the potential clinical relevance of hNS/PCs-OE is worth pursuing.
Asunto(s)
Linaje de la Célula , Hipocampo/citología , Células-Madre Neurales/citología , Mucosa Olfatoria/citología , Adulto , Animales , Anticuerpos Neutralizantes/farmacología , Astrocitos/citología , Astrocitos/efectos de los fármacos , Biomarcadores/metabolismo , Diferenciación Celular/efectos de los fármacos , Linaje de la Célula/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Citocinas/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Receptores ErbB/metabolismo , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones Endogámicos C57BL , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Fosforilación/efectos de los fármacos , Receptor trkB/metabolismo , Solubilidad , Activación Transcripcional/efectos de los fármacosRESUMEN
Neural progenitor cells (NPC) contained in the human adult olfactory neuroepithelium (ONE) possess an undifferentiated state, the capability of self-renewal, the ability to generate neural and glial cells as well as being kept as neurospheres in cell culture conditions. Recently, NPC have been isolated from human or animal models using high-risk surgical methods. Therefore, it was necessary to improve methodologies to obtain and maintain human NPC as well as to achieve better knowledge of brain disorders. In this study, we propose the establishment and characterization of NPC cultures derived from the human olfactory neuroepithelium, using non-invasive procedures. Twenty-two healthy individuals (29.7 ± 4.5 years of age) were subjected to nasal exfoliation. Cells were recovered and kept as neurospheres under serum-free conditions. The neural progenitor origin of these neurospheres was determined by immunocytochemistry and qPCR. Their ability for self-renewal and multipotency was analyzed by clonogenic and differentiation assays, respectively. In the cultures, the ONE cells preserved the phenotype of the neurospheres. The expression levels of Nestin, Musashi, Sox2, and ßIII-tubulin demonstrated the neural origin of the neurospheres; 48% of the cells separated could generate neurospheres, determining that they retained their self-renewal capacity. Neurospheres were differentiated in the absence of growth factors (EGF and FGF), and their multipotency ability was maintained as well. We were also able to isolate and grow human neural progenitor cells (neurospheres) through nasal exfoliates (non-invasive method) of the ONE from healthy adults, which is an extremely important contribution for the study of brain disorders and for the development of new therapies.
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Células-Madre Neurales/fisiología , Células Neuroepiteliales/fisiología , Mucosa Olfatoria/citología , Mucosa Olfatoria/fisiología , Adulto , Células Cultivadas , Femenino , Humanos , MasculinoRESUMEN
The generation of new neurons during adulthood involves local precursor cell migration and terminal differentiation in the dentate gyrus. These events are influenced by the hippocampal microenvironment. Brain-derived neurotrophic factor (BDNF) is relevant for hippocampal neuronal development and behavior. Interestingly, studies that have been performed in controlled in vitro systems that involve isolated precursor cells that were derived from the dentate gyrus (AHPCs) have shown that BDNF induces the activation of the TrkB receptor and, consequentially, might activate signaling pathways that favor survival and neuronal differentiation. Based on the fact that the cellular events of AHPCs that are induced by single factors can be studied in this controlled in vitro system, we investigated the ability of BDNF and the involvement of protein kinase C (PKC), as one of the TrkB-downstream activated signaling proteins, in the regulation of migration, here reflected by motility, of AHPCs. Precursor cells were cultured following a concentration-response curve (1-640 ng/ml) for 24 or 96 h. We found that BDNF favored cell survival without altering the viability under culture proliferative conditions of the AHPCs. Concomitantly, glial- and neuronal-differentiated precursor cells increased as a consequence of survival promoted by BDNF. Additionally, pharmacological approaches showed that BDNF (40 ng/ml)-induced migration of AHPCs was blocked with the compounds K252a and GF109203x, which prevent the activation of TrkB and PKC, respectively. The results indicate that in the in vitro migration of differentiated AHPCs it is involved the BDNF and TrkB cascade. Our results provide additional information about the mechanism by which BDNF impacts adult neurogenesis in the hippocampus.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Movimiento Celular/fisiología , Supervivencia Celular/fisiología , Hipocampo/metabolismo , Neurogénesis/fisiología , Neuronas/metabolismo , Células Madre Adultas/citología , Células Madre Adultas/efectos de los fármacos , Células Madre Adultas/metabolismo , Animales , Factor Neurotrófico Derivado del Encéfalo/administración & dosificación , Carbazoles/farmacología , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Femenino , Hipocampo/citología , Hipocampo/efectos de los fármacos , Alcaloides Indólicos/farmacología , Indoles/farmacología , Maleimidas/farmacología , Ratones Endogámicos C57BL , Células-Madre Neurales/citología , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/metabolismo , Neurogénesis/efectos de los fármacos , Neuroglía/citología , Neuroglía/efectos de los fármacos , Neuroglía/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismo , Receptor trkB/antagonistas & inhibidores , Receptor trkB/metabolismoRESUMEN
In humans, new neurons are continuously added in the olfactory epithelium even in the adulthood. The resident neural stem/progenitor cells (hNS/PCs-OE) in the olfactory epithelium are influenced by several growth factors and neurotrophins. Among these modulators the vascular endothelial growth factor (VEGF) has attracted attention due its implicated in cell proliferation, survival and migration of other type of neural/stem progenitor cells. Interestingly, VEGFr2 receptor expression in olfactory epithelium has been described in amphibians but not in humans. Here we show that VEGFr is expressed in the hNS/PCs-OE. We also investigated the effect of VEGF on the hNS/PCs-OE proliferation, viability and migration in vitro. Additionally, pharmacological approaches showed that VEGF (0.5 ng/ml)-stimulated migration of hNS/PCs-OE was blocked with the compound DMH4, which prevents the activation of VEGFr2. Similar effects were found with the inhibitors for Rac (EHT1864) and p38MAPK (SB203850) proteins, respectively. These observations occurred with changes in focal adhesion contacts. However, no effects of VEGF on proliferation or viability were found in hNS/PCs-OE. Our results suggest that hNS/PCs-OE respond to VEGF involving VEGFr2, Rac and p38MAPK.
Asunto(s)
Movimiento Celular/fisiología , Proliferación Celular/fisiología , Adhesiones Focales/metabolismo , Células-Madre Neurales/metabolismo , Mucosa Olfatoria/metabolismo , Factor A de Crecimiento Endotelial Vascular/farmacología , Adhesión Celular/efectos de los fármacos , Adhesión Celular/fisiología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Relación Dosis-Respuesta a Droga , Adhesiones Focales/efectos de los fármacos , Humanos , Células-Madre Neurales/efectos de los fármacos , Mucosa Olfatoria/citología , Mucosa Olfatoria/efectos de los fármacos , Receptor 2 de Factores de Crecimiento Endotelial Vascular/agonistas , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Neurogenesis constitutively occurs in the olfactory epithelium of mammals, including humans. The fact that new neurons in the adult olfactory epithelium derive from resident neural stem/progenitor cells suggests a potential use for these cells in studies of neural diseases, as well as in neuronal cell replacement therapies. In this regard, some studies have proposed that the human olfactory epithelium is a source of neural stem/progenitor cells for autologous transplantation. Although these potential applications are interesting, it is important to understand the cell biology and/or whether human neural stem/progenitor cells in the olfactory epithelium sense external signals, such as brain-derived neurotrophic factor (BDNF), that is also found in other pro-neurogenic microenvironments. BDNF plays a key role in several biological processes, including cell migration. Thus, we characterized human neural stem/progenitor cells derived from the olfactory epithelium (hNS/PCs-OE) and studied their in vitro migratory response to BDNF. In the present study, we determined that hNS/PCs-OE express the protein markers Nestin, Sox2, Ki67 and ßIII-tubulin. Moreover, the doubling time of hNS/PCs-OE was approximately 38h. Additionally, we found that hNS/PCs-OE express the BDNF receptor TrkB, and pharmacological approaches showed that the BDNF-induced (40ng/ml) migration of differentiated hNS/PCs-OE was affected by the compound K252a, which prevents TrkB activation. This observation was accompanied by changes in the number of vinculin adhesion contacts. Our results suggest that hNS/PCs-OE exhibit a migratory response to BDNF, accompanied by the turnover of adhesion contacts.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/farmacología , Movimiento Celular/efectos de los fármacos , Células-Madre Neurales/efectos de los fármacos , Mucosa Olfatoria/citología , Receptor trkB/metabolismo , Carbazoles/farmacología , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Colchicina/farmacología , Inhibidores Enzimáticos/farmacología , Histonas/metabolismo , Humanos , Alcaloides Indólicos/farmacología , Antígeno Ki-67/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Factores de Tiempo , Tubulina (Proteína)/metabolismo , Vinculina/metabolismoRESUMEN
Melatonin is involved in the regulation of hippocampal neuronal development during adulthood. Emerging evidence indicates that exogenous melatonin acts during different events of the neurogenic process and exerts antidepressant-like behavior in rodents. Thus, melatonin might act through different mechanism, including acting as an antioxidant, interacting with intracellular proteins and/or activating membrane receptors. The melatonin membrane receptors (MMRs; Mt1/Mt2) are distributed throughout the hippocampus with an interesting localization in the hippocampal neurogenic microenvironment (niche), suggesting the involvement of these receptors in the beneficial effects of melatonin on hippocampal neurogenesis and behavior. In this study, we analyzed the participation of MMRs in the baseline neurogenesis in C57BL/6 mice. To this end, we used a pharmacological approach, administering luzindole (10 mg/kg) for 14 days. We observed a decrease in the absolute number of doublecortin-positive cells (49%) without changes in either the dendrite complexity of mature doublecortin-cells or the number of apoptotic cells (TUNEL). However, after the chronic administration of luzindole, cell proliferation (Ki67) significantly decreased (36%) with increasing (>100%) number of neural stem cells (NSCs; GFAP(+)/Sox2(+)) in the subgranular zone of the dentate gyrus of the hippocampus. In addition, luzindole did not affect hopelessness-like behavior in the forced swim test (FST) or changes in the novelty suppressed feeding test (NST) after 14 days of treatment either neuronal activation in the dentate gyrus after FST. These results suggest that the MMRs are involved in the effects of endogenous melatonin to mediate the transition from NSCs and proliferative cells to the following developmental stages implicated in the hippocampal neurogenic process of adult female C57BL/6 mice.
Asunto(s)
Depresión/fisiopatología , Hipocampo/efectos de los fármacos , Hipocampo/fisiología , Neurogénesis/efectos de los fármacos , Receptores de Melatonina/antagonistas & inhibidores , Receptores de Melatonina/fisiología , Triptaminas/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Hipocampo/citología , Ratones , Ratones Endogámicos C57BL , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/fisiología , Neuronas/citología , Neuronas/fisiologíaRESUMEN
Because stress may underlie the presence of depressive episodes, strategies to produce protection against or to reverse the effects of stress on neuroplasticity and behavior are relevant. Preclinical studies showed that exposure to stimuli, such as physical activity and environmental enrichment (ENR), produce beneficial effects against stress causing antidepressant-like effects in rodents. Additionally, ENR induces positive effects on neuroplasticity, neurochemistry and behavior at any age of rodents tested. Here, we analyzed whether ENR exposure prevents the development of depressive-like behavior produced by unpredictable, chronic mild stress (CMS) exposure as well as changes in hippocampal neurogenesis in a six-month-old female Balb/C mice, strain that shows low baseline levels of hippocampal neurogenesis. Mice were assigned to one of four groups: (1) normal housing-normal housing (NH-NH), (2) NH-CMS, (3) ENR-NH, or (4) ENR-CMS. The animals were exposed over 46 days to ENR or NH and subsequently to NH or CMS for 4 weeks. ENR induces long-term effects protecting against CMS induction of anhedonia and hopelessness behaviors. Independent of housing conditions, ENR increased the number of proliferative cells (Ki67), and CMS decreased the number of proliferative cells. ENR increased the newborn cells (BrdU) and mature phenotypes of neurons; these effects were not changed by CMS exposure. Similarly, the number of doublecortin-positive cells was not affected by CMS in ENR mice, which showed more cells with complex dendrite arborizations. Our study suggests that ENR induces protection against the effects of CMS on behavior and neuroplasticity in six-month-old Balb/C mice.
Asunto(s)
Ambiente , Neuronas/fisiología , Estrés Psicológico/fisiopatología , Estrés Psicológico/terapia , Anhedonia/fisiología , Animales , Análisis Químico de la Sangre , Bromodesoxiuridina , Proliferación Celular/fisiología , Enfermedad Crónica , Corticosterona/sangre , Giro Dentado/patología , Giro Dentado/fisiopatología , Trastorno Depresivo/patología , Trastorno Depresivo/fisiopatología , Trastorno Depresivo/terapia , Proteínas de Dominio Doblecortina , Ensayo de Inmunoadsorción Enzimática , Femenino , Vivienda para Animales , Inmunohistoquímica , Ratones Endogámicos BALB C , Proteínas Asociadas a Microtúbulos/metabolismo , Células-Madre Neurales/fisiología , Neurogénesis/fisiología , Neuronas/patología , Neuropéptidos/metabolismo , Estrés Psicológico/patologíaRESUMEN
Deep brain stimulation (DBS) is used as an alternative therapeutic procedure for pharmacoresistant psychiatric disorders. Recently the thalamic reticular nucleus (TRN) gained attention due to the description of a novel pathway from the amygdala to this nucleus suggesting that may be differentially disrupted in mood disorders. The limbic system is implicated in the regulation of these disorders that are accompanied by neuroplastic changes. The hippocampus is highly plastic and shows the generation of new neurons, process affected by stress but positively regulated by antidepressant drugs. We explored the impact of applying acute DBS to the TRN (DBS-TRN) in male Wistar rats exposed to acute stress caused by the forced-swim Porsolt's test (FST) and on initial events of hippocampal neurogenesis. After the first session of forced-swim, rats were randomly subdivided in a DBS-TRN and a Sham group. Stimulated rats received 10min of DBS, thus the depressant-like behavior reflected as immobility was evaluated in the second session of forced-swim. Locomotricity was evaluated in the open field test. Cell proliferation and doublecortin-associated cells were quantified in the hippocampus of other cohorts of rats. No effects of electrode implantation were found in locomotricity. Acute DBS-TRN reduced immobility in comparison to the Sham group (p<0.001). DBS-TRN increased cell proliferation (Ki67 or BrdU-positive cells; p=0.02, p=0.02) and the number of doublecortin-cells compared to the Sham group (p<0.02). Similar effects were found in rats previously exposed to the first session of forced-swim. Our data could suggest that TRN brain region may be a promising target for DBS to treat intractable depression.