Corticotropin releasing factor (CRF) has been implicated to act as a neurotransmitter or modulator in central nervous activation during stress. In this study, we examined the regulatory effect of CRF on the expression and function of the norepinephrine transporter (NET) in vitro. SK-N-BE (2) M17 cells were exposed to different concentrations of CRF for different periods. Results showed that exposure of cells to CRF significantly increased mRNA and protein levels of NET in a concentration- and time-dependent manner. The CRF-induced increase in NET expression was mimicked by agonists of either CRF receptor 1 or 2. Furthermore, similar CRF treatments induced a parallel increase in the uptake of [3H] norepinephrine. Both increased expression and function of NET caused by CRF were abolished by simultaneous administration of CRF receptor antagonists, indicating a mediation by CRF receptors. However, there was no additive effect for the combination of both receptor antagonists. Chromatin immunoprecipitation assays confirm an increased acetylation of histone H3 on the NET promoter following treatment with CRF. Taken together, this study demonstrates that CRF up-regulates the expression and function of NET in vitro. This regulation is mediated through CRF receptors and an epigenetic mechanism related to histone acetylation may be involved. This CRF-induced regulation on NET expression and function may play a role in development of stress-related depression and anxiety. This study demonstrated that corticotropin release factor (CRF) up-regulated the expression and function of norepinephrine transporter (NET) in a concentration- and time-dependent manner, through activation of CRF receptors and possible histone acetylation in NET promoter. The results indicate that their interaction may play an important role in stress-related physiological and pathological status. This study demonstrated that corticotropin release factor (CRF) up-regulated the expression and function of norepinephrine transporter (NET) in a concentration- and time-dependent manner, through activation of CRF receptors and possible histone acetylation in NET promoter. The results indicate that their interaction may play an important role in stress-related physiological and pathological status.

Glucocorticoids affect cellular and molecular events in brains by modulating the expression of many genes during stress. In the present study, we examined the regulatory effect of corticosterone on the expression and function of the norepinephrine transporter (NET) in vitro. The results show that exposure of SK-N-BE(2)C cells to corticosterone for 14 days significantly increased mRNA (up to 43%) and protein (up to 71%) levels of NET in the concentration- dependent manner. Longer exposure (21 days) resulted in greater increases in the levels of mRNAs (up to about 160%) and proteins (up to about 250%) of the NET. The up-regulatory effect of corticosterone on NET expression lasted a persistent period after cessation of exposure. Associated with the corticosterone-induced enhancement in NET expression, there was a parallel increase in the uptake of [3H]norepinephrine by SK-N-BE(2)C cells. Increased NET expression and function were abolished after exposure of cells to corticosterone in combination with mifepristone or spironolactone, two specific antagonists of corticosteroid receptors. This is consistent with the hypothesis that corticosterone-induced NET up-regulation is mediated by corticosteroid receptors. Nevertheless, there was no synergistic effect for a combination of both corticosteroid receptor antagonists. A similar up-regulation of NET protein levels was also observed after exposing PC12 cells to corticosterone. The present findings demonstrate that corticosterone up-regulates the expression and function of NET in vitro, indicating the action of corticosterone on the noradrenergic phenotype may play an important role in the correlation between stress and the development of depression.

During differentiation stem cells are exposed to a range of microenvironmental chemical and physical cues. In this study, human multipotent progenitor cells (hMLPCs) were differentiated from umbilical cord into oligodendrocytes and astrocytes. Chemical cues were represented by a novel defined differentiation medium containing the neurotransmitter norepinephrine (NE). In traditional 2 dimensional (2D) conditions, the hMLPCs differentiated into oligodendrocyte precursors, but did not progress further. However, in a constructed 3 dimensional (3D) environment, the hMLPCs differentiated into committed oligodendrocytes that expressed MBP. When co-cultured with rat embryonic hippocampal neurons (EHNs), hMLPCs developed in astrocytes or oligodendrocytes, based on presence of growth factors in the differentiation medium. In co-culture, physical cues provided by axons were essential for complete differentiation of both astrocytes and oligodendrocytes. This study presents a novel method of obtaining glia from human MLPCs that could eliminate many of the difficulties associated with their differentiation from embryonic stem cells. In addition, it reveals the complex interplay between physical cues and biomolecules on stem cell differentiation.

Tem sido estabelecido que microinjeções intraperitoneais (i.p) de Pentilenotetrazol, um antagonista não competitivo dos receptores GABAA, induzem crises convulsivas do tipo tônico-clônicas em animais de laboratório. Esse efeito convulsivante do PTZ ocorre devido ao bloqueio do fluxo de íons cloreto mediado pelo GABA. Adicionalmente, as crises convulsivas evocadas por PTZ em roedores são seguidas por antinocicepção. Tem sido sugerido que a estimulação elétrica do nervo vago pode reduzir as crises convulsivas e muitas das aferências do nervo vago ao núcleo do trato solitário (NTS) usam o glutamato como neurotransmissor. Há trabalhos mostrando que o NTS conectase ao núcleo reticular paragigantocelular (PGi), uma estrutura também responsável pela elaboração de pelo menos parte da antinocicepção pós-ictal, que o PGi projeta-se ao locus coeruleus, cuja estimulação também produz efeito anticonvulsivante e antinociceptivo.. Com intuito de investigar a participação do NTS nas crises convulsivas e na antinocicepção pós-ictal mediado por receptores glutamatérgicos locais do tipo NMDA e neurônios noradrenérgicos (NE) do LC, microinjeções de agonistas e antagonistas NMDA foram feitas no NTS, seguida da administração de PTZ por via i.p. Em adição foi investigado os efeitos da lesão neurotóxica do LC com administrações por via intratecal de DSP-4 , seguidas por microinjeções de NMDA no NTS sobre as crises convulsivas e antinocicepção pós-ictal induzidas por injeções de PTZ por via i.p. O bloqueio ionóforo de canais de cloreto ligado ao GABA causou crises convulsivas19 tônico-clônicas seguidas antinocicepção pós-ictal em todos os animais submetidos ao presente trabalho. Tanto as convulsões como a antinocicepção pós-ictal mostraram-se parcialmente dependentes da atividade de vias mediadas por aminoácidos excitatórios no núcleo do trato solitário, como da integridade do sistema noradrenérgico, pois o bloqueio de receptores de aminoácidos excitatórios do tipo NMDA no NTS e a administração intratecal de uma neurotoxina seletiva para neurônios noradrenérgicos alteraram a gravidade das crises tônico-clônicas e a intensidade da analgesia pós-ictal. Esses dados sugerem que o sistema glutamatérgico aferente ao NTS e tanto as vias noradrenérgicas ascendentes como descendentes do locus coeruleus são relevantes para o controle das atividades convulsivas e da antinocicepção pós-ictal. / Intraperitoneal injections of the non-competitive GABAA receptor antagonista pentylenetetrazole (PTZ) induce tonic-clonic seizures in laboratory animals. Tha convulsive effect of PTZ is due to GABA-mediated Cl- influx blockade. In addition, seizures caused by PTz in rodents are follwed by significant antinociception. The electrical stimulation of the vagus nerve is known to reduce seizures and several inputs from nervus vagus do the nucleus of the tractus solitarius (NTS) use glutamate as neurotransmitter. There are reports showing that the NTS is connected to the nucleus reticularis paragigantocellularis (PGi), a ventromedial medula oblongata structure also related to the elaboration of at least part of the post-ictal antinociception, and the PGi sends outputs to the locus coeruleus, whose stimulation also cause both anticonvulsant and antinociceptive effects. The goal of the present work was to investigate the involvement of the NTS in both seizures and post-ictal antinociception control mediated by NMDA receptors as well as the role played by noradrenergic neurons from locus coeruleus (LC). Either NMDA agonists or antagonists were microinjected in the NTS, followed by i.p. PTZ injections. In addition, it was investigated the effects of LC neurotoxic lesions with intrathecal injections of DSP-4, followed by NMDA receptor agonists microinjections in the NTS, on both tonic-clonic seizures and post-ictal antinociception elicited by peripheral administrations of PTZ. The ionophore blockade of GABA-mediated Cl- influx caused tonic-clonic seizures follwed by significant post21 ictal antinociception in all animals submitted to the present work. Both tonic-clonic seizures and the post-ictal antinociception were percially dependent of the neural activity of excitatory aminoacid-mediated neurotransmission in the NTS of seizing Wistar rats in addition to the integrity of noradrenergic system, since the NMDA receptors blockade in the NTS and the intra-thecal administration of DSP-4 . The neurotoxin selective to LC noradrenergic neurons modified the severity of tonic-clonic seizures and the intensity of post-ictal antinociception. These findings suggest that the glutamatergic inputs to the NTS, in addition to ascending and descending noradrenergic pathways from LC are critical to the control of both seizures and post-ictal antinociception.

Análise proteômica das glândulas de veneno e acessória durante o ciclo de produção de veneno e a influência da inervação noradrenérgica na síntese de proteínas foi verificada. Nossos dados mostram que a síntese de proteínas envolvidas no processo de síntese e secreção de proteínas está aumentada nos estágios ativados da glândula de veneno e que a estimulação da inervação noradrenérgica regula a síntese de algumas proteínas importantes para estes processos. Mostramos pela primeira vez, a presença de várias toxinas no estágio quiescente da glândula e que a produção e secreção de toxinas ocorrem de maneira não sincronizada. Na glândula acessória verificamos uma modulação na síntese de algumas proteínas da glândula após a extração de veneno. Mostramos também a presença de várias toxinas e de inibidores de enzimas do veneno nesta glândula. A composição proteômica das glândulas do aparelho glandular de veneno de serpente contribuirá para um melhor conhecimento dos mecanismos de produção e secreção de veneno e para os estudos das toxinas e suas diversidades. / Proteomic analysis of venom gland and accessory gland during venom production cycle and the influence of noradrenergic innervation on protein synthesis of venom gland were verified. Our data show that the synthesis of proteins involved in the process of synthesis and secretion of proteins is increased in activated stages of venom gland and the sympathetic outflow regulates the synthesis of some proteins that is important to this process. For the first time we showed that many toxins are present in quiescent stage of venom gland and the production and secretion of toxins is not synchronized. Regarding the accessory gland, we verify that the syntheses of some protein of gland were regulated after venom extraction. We also showed the presence of some toxins of the venom and enzyme inhibitors in this gland. The proteomic composition of snake venom gland apparatus will contribute to better understand the mechanisms involved in venom gland activation and consequently, venom production. These data will also contribute to the studies on snake toxins and their diversities.

Le Trouble de Stress Post-Traumatique (TSPT) est une pathologie qui se développe chez des sujets exposés à des événements traumatiques. Cette pathologie est caractérisée par des reviviscences du traumatisme induisant des troubles anxieux invalidants et durables. Ces reviviscences, provoquées par des indices de rappel, sont à l'origine des fréquentes rechutes qui caractérisent le TSPT. La dépendance aux drogues d'abus est également caractérisée par une hyperréactivité aux indices de rappel qui est responsable du désir irrépressible de drogue ou " craving " et des nombreuses rechutes après abstinence. Nous avons fait l'hypothèse que cette susceptibilité aux indices environnementaux, commune aux deux pathologies, pourrait être due à un découplage des systèmes monoaminergiques induit par l'exposition à des conditions intenses, drogues d'abus ou traumatisme. Les données de cette thèse montrent que notre modèle animal de traumatisme (le Single Prolonged Stress) reproduit chez les individus vulnérables les symptômes de la pathologie, et une réactivité aux indices de rappel. Nos données indiquent également qu'un traumatisme induit, chez les individus vulnérables, une désensibilisation comportementale et une sensibilisation noradrénergique corticale, supportant l'hypothèse de découplage monoaminergique. Enfin, nous avons développé une nouvelle approche thérapeutique, le " remodelage émotionnel " capable de diminuer durablement les symptômes de type TSPT. Les résultats obtenus dans cette thèse, soutiennent l'hypothèse de bases physiologiques communes entre le TSPT et l'addiction, et proposent de nouvelles approches thérapeutiques pour ces deux pathologies. / Post-Traumatic Stress disorder (PSTD) appears on a part of individuals exposed to traumatic events. This pathology is characterized by frequent re-experiencing of the traumatic event inducing disabling and long-lasting anxiety disorders. These flashbacks, triggered by reminder cues, are responsible for the frequent relapses that characterize PTSD. Addiction to drugs of abuse is also characterized by a hyper reactivity to reminder cues which is responsible for drug craving and relapses. We hypothesized that such a susceptibility to environmental cues, common to both pathologies, could be due to an uncoupling of monoaminergic systems induced by exposure to intense conditions (trauma or drugs). Data from this thesis showed that our animal model of PTSD (the Single Prolonged Stress) reproduced PTSD-like symptoms on vulnerable rats, and reactivity to reminder cues. Our data also showed that trauma induced a behavioral desensitization and a cortical noradrenergic sensitization, in vulnerable traumatized rats, supporting the hypothesis of monoaminergic uncoupling. Finally, we developed a new therapeutic approach, the "emotional remodeling" which was shown to durably decrease PTSD-like symptoms. The results obtained in this thesis support the hypothesis of common physiological basis between PTSD and drug addiction, and offer new therapeutic approaches for these two pathologies.

Análise proteômica das glândulas de veneno e acessória durante o ciclo de produção de veneno e a influência da inervação noradrenérgica na síntese de proteínas foi verificada. Nossos dados mostram que a síntese de proteínas envolvidas no processo de síntese e secreção de proteínas está aumentada nos estágios ativados da glândula de veneno e que a estimulação da inervação noradrenérgica regula a síntese de algumas proteínas importantes para estes processos. Mostramos pela primeira vez, a presença de várias toxinas no estágio quiescente da glândula e que a produção e secreção de toxinas ocorrem de maneira não sincronizada. Na glândula acessória verificamos uma modulação na síntese de algumas proteínas da glândula após a extração de veneno. Mostramos também a presença de várias toxinas e de inibidores de enzimas do veneno nesta glândula. A composição proteômica das glândulas do aparelho glandular de veneno de serpente contribuirá para um melhor conhecimento dos mecanismos de produção e secreção de veneno e para os estudos das toxinas e suas diversidades. / Proteomic analysis of venom gland and accessory gland during venom production cycle and the influence of noradrenergic innervation on protein synthesis of venom gland were verified. Our data show that the synthesis of proteins involved in the process of synthesis and secretion of proteins is increased in activated stages of venom gland and the sympathetic outflow regulates the synthesis of some proteins that is important to this process. For the first time we showed that many toxins are present in quiescent stage of venom gland and the production and secretion of toxins is not synchronized. Regarding the accessory gland, we verify that the syntheses of some protein of gland were regulated after venom extraction. We also showed the presence of some toxins of the venom and enzyme inhibitors in this gland. The proteomic composition of snake venom gland apparatus will contribute to better understand the mechanisms involved in venom gland activation and consequently, venom production. These data will also contribute to the studies on snake toxins and their diversities.

Our primary goal was to determine if leukocytes are a source of nerve growth factor (NGF) in mouse spleen. Noradrenergic nerves were localized to arteries and white pulp in normal spleens but only to arteries in ultra-immunodeficient R2G2 mice that lack leukocytes. NGF mRNA was detected in vascular cells and leukocytes of normal spleen, and several of the latter were T cells based on double labeling for NGF mRNA and CD3. Our findings indicate NGF is produced by vascular cells and to a lesser extent by leukocytes in spleen and provide support for pleiotropic actions in spleen and salivary glands.

No description available.

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