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TaqIA is a polymorphism associated with addictions and dopamine-related traits. It is located in the ankyrin repeat and kinase domain containing 1 gene (ANKK1) nearby the gene for the dopamine D2 receptor (D2R). Since ANKK1 function is unknown, TaqIA-associated traits have been explained only by differences in D2R. Here we report ANKK1 studies in mouse and human brain using quantitative real-time PCR, Western blot, immunohistochemistry, and flow cytometry. ANKK1 mRNA and protein isoforms vary along neurodevelopment in the human and mouse brain. In mouse adult brain ANKK1 is located in astrocytes, nuclei of postmitotic neurons and neural precursors from neurogenic niches. In both embryos and adults, nuclei of neural precursors show significant variation of ANKK1 intensity. We demonstrate a correlation between ANKK1 and the cell cycle. Cell synchronization experiments showed a significant increment of ANKK1-kinase in mitotic cells while ANKK1-kinase overexpression affects G1 and M phase that were found to be modulated by ANKK1 alleles and apomorphine treatment. Furthermore, during embryonic neurogenesis ANKK1 was expressed in slow-dividing neuroblasts and rapidly dividing precursors which are mitotic cells. These results suggest a role of ANKK1 during the cell cycle in neural precursors thus providing biological support to brain structure involvement in the TaqIA-associated phenotypes.

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Estudios recientes han evidenciado que la autofagia puede actuar como un mecanismo inmune protector frente a la infección con Listeria monocytogenes. L. monocytogenes es una bacteria grampositiva, intracelular facultativa, que causa enfermedades invasivas en humanos y animales, especialmente en el sistema nervioso central (SNC). La listeriosis humana en el SNC puede manifestarse de diferentes maneras, incluyendo meningitis y abscesos cerebrales. La línea principal de defensa frente a las infecciones bacterianas es proporcionada por la microglía, fagocitos residentes del parénquima del SNC. Las células de microglía son conocidas, también, por eliminar las células dañadas o muertas tras un daño cerebral, y por lo tanto desempeñan un papel clave en las enfermedades infecciosas y neurodegenerativas. Se sabe poco sobre el papel de la autofagia en las interacciones entre el hospedador y el patógeno, debido a que la mayoría de los estudios in vitro han usado macrófagos o células epiteliales. En el presente trabajo hemos utilizado matrices de PCR en tiempo real para analizar la expresión de genes de autofagia en un modelo organotípico de cerebro de rata infectado con L. monocytogenes. Hemos observado que, en general, la expresión de genes centrales de la autofagia no está modulada por la infección, a pesar de la presencia de una intensa actividad fagocítica de la microglía en la superficie del tejido cerebral, observada mediante microscopia electrónica de barrido. Concluimos que, en nuestro modelo, la autofagia podría desempeñar un papel clave en la homeostasis del tejido dañado en lugar de tener un papel inmune relevante(AU)

Recent studies have suggested that autophagy can act as a protective immune mechanism against Listeria monocytogenes infection. L. monocytogenes is a Gram-positive, facultative intracellular bacterium that causes invasive diseases in humans and animals, particularly in the central nervous system (CNS). Human listeriosis of the CNS can manifest in many ways, including meningitis and brain abscesses. The initial line of defence against bacterial colonisation is provided by microglia, resident phagocytes of the CNS parenchyma. Microglial cells are also well known for clearing dead and dying neural cells after injury, and therefore play a key role in infectious diseases and neurodegeneration. Little is known about the role of the autophagy pathway in host–pathogen interactions in the brain as most in vitro studies have used macrophages or epithelial cells to study this interaction. In the present work, a quantitative real time-PCR array analysis was performed to assess autophagy-related gene expression in a brain rat ex vivo organotypic nervous system model during L. monocytogenes infection. We found that, in brief, core autophagy gene expression is not modulated by the infection, despite the presence of intense microglial phagocytic activity on the brain tissue surface that can be seen by scanning electron microscopy. We conclude that, in our model, autophagy could play a role in homeostasis in the damaged brain tissue instead of an immune-relevant pathway (AU)

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A wide variety of microorganisms has previously been identified as causes of brain infection. Among them, Listeria monocytogenes has a particular tropism for the central nervous system. To gain knowledge about the immune response elicited by L. monocytogenes in the brain, we used a rat ex vivo organotypic nervous system culture as a model for Listeria infection. Scanning electron microscopy (SEM) revealed that activated microglial cells showing a typical amoeboid morphology are quickly recruited to the surface of the explants after the infection. After bacterial engulfment, these cells appear to act as Trojan horses, releasing the engulfed bacteria inside the brain tissue. We describe cycles of microglial phagocytosis, necrotic cell death and the subsequent removal of cell debris for the first time. Furthermore, we used this ex vivo model to assess the expression profiles of immune relevant genes up to 24 h postinfection by means of q-PCR-arrays, finding that a number of inflammation-promoting genes are upregulated. Shortly after infection by L. monocytogenes, upregulated genes were those that encoded molecules involved in Th1 responses, being the Ccl2 chemokine and members of the interleukin1-ß family the most abundant immunomodulatory signals expressed. After 5 h of infection, L. monocytogenes caused a substantial increase in the expression of TLR1 and TLR2 genes, as well as in several downstream genes of the TLR signaling pathways.

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5-HT1A receptors couple to different Go/Gi proteins in order to mediate a wide range of physiological actions. While activation of post-synaptic 5-HT1A receptors is mainly related to inhibition of adenylyl cyclase activity, functionality of autoreceptors located in raphe nuclei has been classically ascribed to modifications of the activity of potassium and calcium channels. In order to evaluate the possible existence of agonist-directed trafficking for 5-HT1A autoreceptors in the rat dorsal raphe nucleus, we studied their activation by two agonists with a different profile of efficacy [(+)8-OH-DPAT and buspirone], addressing simultaneously the identification of the specific Galpha subtypes ([35S]GTPgammaS labelling and immunoprecipitation) involved and the subsequent changes in cAMP formation. A significant increase (32%, p<0.05) in (+)8-OH-DPAT-induced [35S]GTPgammaS labelling of immunoprecipitates was obtained with anti-Galphai3 antibodies but not with anti-Galphao, anti-Galphai1, anti-Galphai2, anti-Galphaz or anti-Galphas antibodies. In contrast, in the presence of buspirone, significant [35S]GTPgammaS labelling of immunoprecipitates was obtained with anti-Galphai3 (50%, p<0.01), anti-Galphao (32%, p<0.01) and anti-Galphai2 (29%, p<0.05) antibodies, without any labelling with anti-Galphai1, anti-Galphaz or anti-Galphas. The selective 5-HT1A antagonist WAY 100635 blocked the labelling induced by both agonists. Furthermore, (+)8-OH-DPAT failed to modify forskolin-stimulated cAMP accumulation, while buspirone induced a dose-dependent, WAY 100635-sensitive, inhibition of this response (Imax 30.8+/-4.9, pIC50 5.95+/-0.46). These results demonstrate the existence of an agonist-dependency pattern of G-protein coupling and transduction for 5-HT1A autoreceptors in native brain tissue. These data also open new perspectives for the understanding of the differential profiles of agonist efficacy in pre- vs. post-synaptic 5-HT1A receptor-associated responses.

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P-glycoprotein (PGP) is a membrane protein and product of the MDR-1 gene, which acts as an efflux pump for several drugs, such as protease inhibitors (PI) used in HIV. Numerous studies in vitro, in experimental animals, and in patients have analyzed the relationships between PGP and the pharmacokinetic and pharmacodynamic properties of antiretroviral agents, with differing conclusions. In addition, studies focusing on the impact of single nucleotide polymorphisms in the MDR-1 gene, mainly C3435T in exon 26 and G2677A/G2677T in exon 21, on antiretroviral plasma concentrations, efficacy and adverse effects, have reported varying results, which have been attributed to the influence of other polymorphisms, such as cytochrome P450.

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La glucoproteína P (PGP) es una proteína de membrana, producto del gen MDR-1, que actúa como bomba expulsora de diversos fármacos, entre ellos los inhibidores de proteasa (IP) del virus de la inmunodeficiencia humana (VIH). Numerosos estudios in vitro, en animales y en pacientes, han analizado las relaciones de esta proteína con la farmacocinética y farmacodinamia de los antirretrovirales, con conclusiones dispares. Por otra parte, las publicaciones que analizan la influencia de los polimorfismos de nucleótido único del gen MDR-1, principalmente el C3435T en el exón 26, y el G2677A/G2677T en el exón 21, con las concentraciones plasmáticas de los antirretrovirales, su eficacia y efectos secundarios también demuestran resultados variables que se han tratado de explicar mediante la influencia de otros polimorfismos como el del citocromo p-450 (AU)

P-glycoprotein (PGP) is a membrane protein and product of the MDR-1 gene, which acts as an efflux pump for several drugs, such as protease inhibitors (PI) used in HIV. Numerous studies in vitro, in experimental animals, and in patients have analyzed the relationships between PGP and the pharmacokinetic and pharmacodynamic properties of antiretroviral agents, with differing conclusions. In addition, studies focusing on the impact of single nucleotide polymorphisms in the MDR-1 gene, mainly C3435T in exon 26 and G2677A/G2677T in exon 21, on antiretroviral plasma concentrations, efficacy and adverse effects, have reported varying results, which have been attributed to the influence of other polymorphisms, such as cytochrome P450 (AU)

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