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  • 1.
    Abbey-Lee, Robin N.
    et al.
    Linkoping Univ, IFM Biol, Dept Phys Chem & Biol, SE-58183 Linkoping, Sweden.
    Uhrig, Emily J.
    Linkoping Univ, IFM Biol, Dept Phys Chem & Biol, SE-58183 Linkoping, Sweden.
    Zidar, Josefina
    Linkoping Univ, IFM Biol, Dept Phys Chem & Biol, SE-58183 Linkoping, Sweden.
    Favati, Anna
    Stockholm Univ, Dept Zool, Stockholm, Sweden.
    Almberg, Johan
    Linkoping Univ, IFM Biol, Dept Phys Chem & Biol, SE-58183 Linkoping, Sweden.
    Dahlbom, Josefin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Lövlie, Hanne
    Linkoping Univ, IFM Biol, Dept Phys Chem & Biol, SE-58183 Linkoping, Sweden.
    The Influence of Rearing on Behavior, Brain Monoamines, and Gene Expression in Three-Spined Sticklebacks2018In: Brain, behavior, and evolution, ISSN 0006-8977, E-ISSN 1421-9743, Vol. 91, no 4, p. 201-213Article in journal (Refereed)
    Abstract [en]

    The causes of individual variation in behavior are often not well understood, and potential underlying mechanisms include both intrinsic and extrinsic factors, such as early environmental, physiological, and genetic differences. In an exploratory laboratory study, we raised three-spined sticklebacks (Gasterosteus aculeatus) under 4 different environmental conditions (simulated predator environment, complex environment, variable social environment, and control). We investigated how these manipulations related to behavior, brain physiology, and gene expression later in life, with focus on brain dopamine and serotonin levels, turnover rates, and gene expression. The different rearing environments influenced behavior and gene expression, but did not alter monoamine levels or metabolites. Specifically, compared to control fish, fish exposed to a simulated predator environment tended to be less aggressive, more exploratory, and more neophobic; and fish raised in both complex and variable social environments tended to be less neophobic. Exposure to a simulated predator environment tended to lower expression of dopamine receptor DRD4A, a complex environment increased expression of dopamine receptor DRD1B, while a variable social environment tended to increase serotonin receptor 5-HTR2B and serotonin transporter SLC6A4A expression. Despite both behavior and gene expression varying with early environment, there was no evidence that gene expression mediated the relationship between early environment and behavior. Our results confirm that environmental conditions early in life can affect phenotypic variation. However, the mechanistic pathway of the monoaminergic systems translating early environmental variation into observed behavioral responses was not detected.

  • 2.
    Abreu, Murilo S.
    et al.
    Fed Univ Santa Maria UFSM, Grad Program Pharmacol, BR-97105900 Santa Maria, RS, Brazil.
    Messias, Joao P. M.
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet, CIBIO, Campus Agr Vairao, P-4485661 Vairao, Portugal.
    Thörnqvist, Per-Ove
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Soares, Marta C.
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet, CIBIO, Campus Agr Vairao, P-4485661 Vairao, Portugal.
    Monoaminergic levels at the forebrain and diencephalon signal for the occurrence of mutualistic and conspecific engagement in client reef fish2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 7346Article in journal (Refereed)
    Abstract [en]

    Social interactions are commonly found among fish as in mammals and birds. While most animals interact socially with conspecifics some however are also frequently and repeatedly observed to interact with other species (i.e. mutualistic interactions). This is the case of the (so-called) fish clients that seek to be cleaned by other fish (the cleaners). Clients face an interesting challenge: they raise enough motivation to suspend their daily activities as to selectively visit and engage in interactions with cleaners. Here we aimed, for the first time, to investigate the region-specific brain monoaminergic level differences arising from individual client fish when facing a cleaner (interspecific context) compared to those introduced to another conspecific (socio-conspecific context). We show that monoaminergic activity differences occurring at two main brain regions, the diencephalon and the forebrain, are associated with fish clients' social and mutualistic activities. Our results are the first demonstration that monoaminergic mechanisms underlie client fish mutualistic engagement with cleanerfish. These pathways should function as a pre-requisite for cleaning to occur, providing to clients the cognitive and physiological tools to seek to be cleaned.

  • 3.
    Alenkvist, Ida
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Dyachok, Oleg
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Tian, Geng
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Li, Jia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Mehrabanfar, Saba
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Jin, Yang
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Tengholm, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Welsh, Michael
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Cell Biology.
    Absence of Shb impairs insulin secretion by elevated FAK activity in pancreatic islets2014In: Journal of Endocrinology, ISSN 0022-0795, E-ISSN 1479-6805, Vol. 223, no 3, p. 267-275Article in journal (Refereed)
    Abstract [en]

    The Src homology-2 domain containing protein B (SHB) has previously been shown to function as a pleiotropic adapter protein, conveying signals from receptor tyrosine kinases to intracellular signaling intermediates. The overexpression of Shb in β-cells promotes β-cell proliferation by increased insulin receptor substrate (IRS) and focal adhesion kinase (FAK) activity, whereas Shb deficiency causes moderate glucose intolerance and impaired first-peak insulin secretion. Using an array of techniques, including live-cell imaging, patch-clamping, immunoblotting, and semi-quantitative PCR, we presently investigated the causes of the abnormal insulin secretory characteristics in Shb-knockout mice. Shb-knockout islets displayed an abnormal signaling signature with increased activities of FAK, IRS, and AKT. β-catenin protein expression was elevated and it showed increased nuclear localization. However, there were no major alterations in the gene expression of various proteins involved in the β-cell secretory machinery. Nor was Shb deficiency associated with changes in glucose-induced ATP generation or cytoplasmic Ca(2) (+) handling. In contrast, the glucose-induced rise in cAMP, known to be important for the insulin secretory response, was delayed in the Shb-knockout compared with WT control. Inhibition of FAK increased the submembrane cAMP concentration, implicating FAK activity in the regulation of insulin exocytosis. In conclusion, Shb deficiency causes a chronic increase in β-cell FAK activity that perturbs the normal insulin secretory characteristics of β-cells, suggesting multi-faceted effects of FAK on insulin secretion depending on the mechanism of FAK activation.

  • 4.
    Amcoff, Mirjam
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Hallsson, Lara R.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Kolm, Niclas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Male Courtship Pheromones Affect Female Behaviour in the Swordtail Characin ( Corynopoma riisei)2014In: Ethology, ISSN 0179-1613, E-ISSN 1439-0310, Vol. 120, no 5, p. 463-470Article in journal (Refereed)
    Abstract [en]

    Pheromones constitute an important cue used by both males and females during courtship. Here, we investigate the effect of male pheromones on female behaviour in the swordtail characin (Corynopoma riisei), a species of fish where males have a caudal pheromone gland which has been suggested to affect female behaviour during courtship. We subjected female C.riisei to male courtship pheromones and investigated the effect on both female behaviour and brain serotonergic activity levels compared to a control group. While no difference in serotonergic activity was found, the pheromone-treated females showed lower stress levels compared to the control group. Furthermore, pheromone-treated females increased locomotor activity over time, while a decrease in locomotor activity was observed in the control group. These results suggest that the male courtship pheromones may serve to reduce female stress and increase female activity, possibly to aid males in gaining access to females and facilitating sperm transfer.

  • 5.
    Ammoun, Sylwia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Holmqvist, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Shariatmadari, Ramin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Oonk, Hendrica B.
    Detheux, Michel
    Parmentier, Marc
    Åkerman, Karl E. O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Kukkonen, Jyrki P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Distinct Recognition of OX1 and OX2 Receptors by Orexin Peptides2003In: Journal of Pharmacology and Experimental Therapeutics, ISSN 0022-3565, E-ISSN 1521-0103, Vol. 305, no 2, p. 507-514Article in journal (Refereed)
    Abstract [en]

    In this study, we have compared the abilities of orexin-A and orexin-B and variants of orexin-A to activate different Ca(2+) responses (influx and release) in human OX(1) and OX(2) receptor- expressing Chinese hamster ovary cells. Responses mediated by activation of both receptor subtypes with either orexin-A or -B were primarily dependent on extracellular Ca(2+), suggesting similar activation of Ca(2+) influx as we have previously shown for orexin-A and OX(1) receptors. Amino acid-wise truncation of orexin-A reduced its ability to activate OX(1) and OX(2) receptors, but the response mediated by the OX(2) receptor was more resistant to truncation than the response mediated by the OX(1) receptor. We also performed a sequential replacement of amino acids 14 to 26 with alanine in the truncated orexin-A variant orexin-A(14-33). Replacement of the same amino acids produced a fall in the potency for each receptor subtype, but the reduction was less prominent for the OX(2) receptor. The most marked reduction was produced by the replacement of Leu20, Asp25, and His26 with alanine. Interestingly, extracellular Ca(2+) dependence of responses to some of the mutated peptides was different from those of orexin-A and -B. The mutagenesis also suggests that although the determinants required from orexin-A for binding to and activation of the receptor are highly conserved between the orexin receptor subtypes, the OX(2) receptor requires fewer determinants. This might in part explain why orexin-B has the affinity and potency equal to orexin-A for this subtype, although it has 10- to 100-fold lower affinity and potency for the OX(1) receptor.

  • 6.
    Ammoun, Sylwia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Johansson, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Ekholm, Marie E.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Holmqvist, Tomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Danis, Alexander S.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Korhonen, Laura
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Sergeeva, Olga A.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Haas, Helmut L.
    Åkerman, Karl E. O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Kukkonen, Jyrki P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    OX1 orexin receptors activate extracellular signal-regulated kinase in Chinese hamster ovary cells via multiple mechanisms: the role of Ca2+ influx in OX1 receptor signaling2006In: Molecular Endocrinology, ISSN 0888-8809, E-ISSN 1944-9917, Vol. 20, no 1, p. 80-99Article in journal (Refereed)
    Abstract [en]

    Activation of OX1 orexin receptors heterologously expressedin Chinese hamster ovary (CHO) cells led to a rapid, strong,and long-lasting increase in ERK phosphorylation (activation).Dissection of the signal pathways to ERK using multiple inhibitorsand dominant-negative constructs indicated involvement of Ras,protein kinase C, phosphoinositide-3-kinase, and Src. Most interestingly,Ca2+ influx appeared central for the ERK response in CHO cells,and the same was indicated in recombinant neuro-2a cells andcultured rat striatal neurons. Detailed investigations in CHOcells showed that inhibition of the receptor- and store-operatedCa2+ influx pathways could fully attenuate the response, whereasinhibition of the store-operated Ca2+ influx pathway alone orthe Ca2+ release was ineffective. If the receptor-operated pathwaywas blocked, an exogenously activated store-operated pathwaycould take its place and restore the coupling of OX1 receptorsto ERK. Further experiments suggested that Ca2+ influx, as such,may not be required for ERK phosphorylation, but that Ca2+,elevated via influx, acts as a switch enabling OX1 receptorsto couple to cascades leading to ERK phosphorylation, cAMP elevation,and phospholipase C activation. In conclusion, the data suggestthat the primary coupling of orexin receptors to Ca2+ influxallows them to couple to other signal pathways; in the absenceof coupling to Ca2+ influx, orexin receptors can act as signalintegrators by taking advantage of other Ca2+ influx pathways.

  • 7.
    Ammoun, Sylwia
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Lindholm, Dan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Wootz, Hanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience.
    Åkerman, Karl E. O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Kukkonen, Jyrki P.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    G-protein-coupled OX1 Orexin/hcrtr-1 Hypocretin Receptors Induce Caspase-dependent and -independent Cell Death through p38 Mitogen-/Stress-activated Protein Kinase2006In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 281, p. 834-842Article in journal (Refereed)
    Abstract [en]

    We have investigated the signaling of OX1 receptors to cell death using Chinese hamster ovary cells as a model system. OX1 receptor stimulation with orexin-A caused a delayed cell death independently of cytosolic Ca2+ elevation. The classical mitogen-activated protein kinase (MAPK) pathways, ERK and p38, were strongly activated by orexin-A. p38 was essential for induction of cell death, whereas the ERK pathway appeared protective. A pathway often implicated in the p38-mediated cell death, activation of p53, did not mediate the cell death, as there was no stabilization of p53 or increase in p53-dependent transcriptional activity, and dominant-negative p53 constructs did not inhibit cell demise. Under basal conditions, orexin-A-induced cell death was associated with compact chromatin condensation and it required de novo gene transcription and protein synthesis, the classical hallmarks of programmed (apoptotic) cell death. However, though the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-(O-methyl)fluoromethyl ketone (Z-VAD-fmk) fully inhibited the caspase activity, it did not rescue the cells from orexin-A-induced death. In the presence of Z-VAD-fmk, orexin-A-induced cell death was still dependent on p38 and de novo protein synthesis, but it no longer required gene transcription. Thus, caspase inhibition causes activation of alternative, gene transcription-independent death pathway. In summary, the present study points out mechanisms for orexin receptor-mediated cell death and adds to our general understanding of the role of G-protein-coupled receptor signaling in cell death by suggesting a pathway from G-protein-coupled receptors to cell death via p38 mitogen-/stress-activated protein kinase independent of p53 and caspase activation.

  • 8.
    Babateen, Omar
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Bhandage, Amol K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Korol, Sergiy V
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Westermark, Bengt
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Forsberg Nilsson, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Uhrbom, Lene
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Cancer and Vascular Biology.
    Smits, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Etomidate, propofol and diazepam potentiate GABA-evoked GABAA currents in a cell line derived from Human glioblastoma2015In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 748, p. 101-107Article in journal (Refereed)
    Abstract [en]

    GABAA receptors are pentameric chloride ion channels that are opened by GABA. We have screened a cell line derived from human glioblastoma, U3047MG, for expression of GABAA receptor subunit isoforms and formation of functional ion channels. We identified GABAA receptors subunit α2, α3, α5, β1, β2, β3, δ, γ3, π, and θ mRNAs in the U3047MG cell line. Whole-cell GABA-activated currents were recorded and the half-maximal concentration (EC50) for the GABA-activated current was 36μM. The currents were activated by THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and enhanced by the benzodiazepine diazepam (1μM) and the general anesthetics etomidate and propofol (50μM). In line with the expressed GABAA receptors containing at least the α3β3θ subunits, the receptors were highly sensitive to etomidate (EC50=55nM). Immunocytochemistry identified expression of the α3 and β3 subunit proteins. Our results show that the GABAA receptors in the glial cell line are functional and are modulated by classical GABAA receptor drugs. We propose that the U3047MG cell line may be used as a model system to study GABAA receptors function and pharmacology in glial cells.

  • 9.
    Babateen, Omar
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Korol, Sergiy V.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Bhandage, Amol K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Ahemaiti, Aikeremu
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Developmental Genetics.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Liraglutide modulates GABAergic signaling in rat hippocampal CA3 pyramidal neurons predominantly by presynaptic mechanism2017In: BMC Pharmacology & Toxicology, E-ISSN 2050-6511, Vol. 18, article id 83Article in journal (Refereed)
    Abstract [en]

    Background

    γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain where it regulates activity of neuronal networks. The receptor for glucagon-like peptide-1 (GLP-1) is expressed in the hippocampus, which is the center for memory and learning. In this study we examined effects of liraglutide, a GLP-1 analog, on GABA signaling in CA3 hippocampal pyramidal neurons.

    Methods

    We used patch-clamp electrophysiology to record synaptic and tonic GABA-activated currents in CA3 pyramidal neurons in rat hippocampal brain slices.

    Results

    We examined the effects of liraglutide on the neurons at concentrations ranging from one nM to one μM. Significant changes of the spontaneous inhibitory postsynaptic currents (sIPSCs) were only recorded with 100 nM liraglutide and then in just ≈50% of the neurons tested at this concentration. In neurons affected by liraglutide both the sIPSC frequency and the most probable amplitudes increased. When the action potential firing was inhibited by tetrodotoxin (TTX) the frequency and amplitude of IPSCs in TTX and in TTX plus 100 nM liraglutide were similar.

    Conclusions

    The results demonstrate that liraglutide regulation of GABA signaling of CA3 pyramidal neurons is predominantly presynaptic and more limited than has been observed for GLP-1 and exendin-4 in hippocampal neurons.

  • 10.
    Babateen, Omar M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    GABA signaling regulation by GLP-1 receptor agonists and GABA-A receptors modulator2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    GABA (γ-aminobutyric acid) is the main neuroinhibitory transmitter in mammalian brains.  It binds to GABA-A and GABA-B receptors. The GABA-A receptors are ligand-gated chloride channels. A variety of GABA-A receptor agonists and antagonists have been developed to study the GABA-mediated inhibition and to explore new medications. In this thesis I have examined the role of GABA in brain tumors and the effects of the metabolic hormone GLP-1 on GABAergic signaling in neurons.

    I studied if GABA-A receptors subunits were expressed and formed functional ion channels in the glioblastoma cell line U3047MG. I identified the mRNA of 11, α2, α3, α5, β1, β2, β3, δ, γ3, π, θ and ρ2, out of the 19 known GABA-A subunits. Immunostaining demonstrated abundant expression of the α3 and β3 subunits. Interestingly, whole-cell GABA-activated currents were recorded in only 12% of the cells. The GABA-activated currents half-maximal concentration (EC50) was 36 µM. The currents were modulated by diazepam (1 µM) and the general anesthetics propofol (50 µM) and etomidate (EC50 = 50 nM).

    GLP-1 and exendin-4 transiently enhanced the GABA-A receptor-mediated currents in CA3 neurons of the rat hippocampus. The tonic and the spontaneous inhibitory postsynaptic currents increased as compared to control in a concentration dependent manner.  The increase was related to enhanced release of GABA from the presynaptic terminals and increased insertion or affinity of GABA-A receptors in the CA3 postsynaptic neuron. In contrast to GLP-1 and exendin-4, liraglutide enhanced the currents only in a subset of the neurons and the effect was mainly mediated by presynaptic mechanisms. 

    In conclusion, GABA signaling in neurons is modified by the metabolic hormone GLP-1 and its mimetics highlighting the important cross-talk that takes place between the brain and other organs. Medicines modifying GABA signaling in the brain may be important for a number of diseases.  

    List of papers
    1. Etomidate, propofol and diazepam potentiate GABA-evoked GABAA currents in a cell line derived from Human glioblastoma
    Open this publication in new window or tab >>Etomidate, propofol and diazepam potentiate GABA-evoked GABAA currents in a cell line derived from Human glioblastoma
    Show others...
    2015 (English)In: European Journal of Pharmacology, ISSN 0014-2999, E-ISSN 1879-0712, Vol. 748, p. 101-107Article in journal (Refereed) Published
    Abstract [en]

    GABAA receptors are pentameric chloride ion channels that are opened by GABA. We have screened a cell line derived from human glioblastoma, U3047MG, for expression of GABAA receptor subunit isoforms and formation of functional ion channels. We identified GABAA receptors subunit α2, α3, α5, β1, β2, β3, δ, γ3, π, and θ mRNAs in the U3047MG cell line. Whole-cell GABA-activated currents were recorded and the half-maximal concentration (EC50) for the GABA-activated current was 36μM. The currents were activated by THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) and enhanced by the benzodiazepine diazepam (1μM) and the general anesthetics etomidate and propofol (50μM). In line with the expressed GABAA receptors containing at least the α3β3θ subunits, the receptors were highly sensitive to etomidate (EC50=55nM). Immunocytochemistry identified expression of the α3 and β3 subunit proteins. Our results show that the GABAA receptors in the glial cell line are functional and are modulated by classical GABAA receptor drugs. We propose that the U3047MG cell line may be used as a model system to study GABAA receptors function and pharmacology in glial cells.

    National Category
    Basic Medicine
    Identifiers
    urn:nbn:se:uu:diva-239191 (URN)10.1016/j.ejphar.2014.12.001 (DOI)000348840500013 ()25510230 (PubMedID)
    Available from: 2014-12-19 Created: 2014-12-19 Last updated: 2018-01-11
    2. GLP-1 and Exendin-4 Transiently Enhance GABA(A) Receptor-Mediated Synaptic and Tonic Currents in Rat Hippocampal CA3 Pyramidal Neurons
    Open this publication in new window or tab >>GLP-1 and Exendin-4 Transiently Enhance GABA(A) Receptor-Mediated Synaptic and Tonic Currents in Rat Hippocampal CA3 Pyramidal Neurons
    2015 (English)In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 64, no 1, p. 79-89Article in journal (Refereed) Published
    Abstract [en]

    GLP-1 is a hormone that stimulates insulin secretion. Receptors for GLP-1 are also found in the brain, including the hippocampus, the centre for memory and learning. Diabetes mellitus is a risk factor for decreased memory functions. We studied effects of GLP-1 and exendin-4, a GLP-1 receptor agonist, on γ-aminobutyric acid (GABA) signaling in hippocampal CA3 pyramidal neurons. GABA is the main inhibitory neurotransmitter and decreases neuronal excitability. GLP-1 (0.01 – 1 nmol/L) transiently enhanced synaptic and tonic currents and the effects were blocked by exendin(9–39). Ten pmol/L GLP-1 increased both the spontaneous inhibitory postsynaptic current (sIPSC) amplitudes and frequency by a factor of 1.8. In 0.1, 1 nmol/L GLP-1 or 10, 50 or 100 nmol/L exendin-4, only the sIPSC frequency increased. The tonic current was enhanced by 0.01 – 1 nmol/L GLP-1 and by 0.5 – 100 nmol/L exendin-4. When action potentials were inhibited by tetrodotoxin (TTX), IPSCs decreased and currents were no longer potentiated by GLP-1 or exendin-4. In contrast, although the tonic current decreased in TTX, it was still enhanced by GLP-1 or exendin-4. The results demonstrate GLP-1 receptor regulation of hippocampal function and are consistent with GLP-1 receptor agonists enhancing GABAA signaling by pre- and postsynaptic mechanisms.

    National Category
    Public Health, Global Health, Social Medicine and Epidemiology
    Identifiers
    urn:nbn:se:uu:diva-234954 (URN)10.2337/db14-0668 (DOI)000346765600010 ()
    Available from: 2014-10-27 Created: 2014-10-27 Last updated: 2017-12-05Bibliographically approved
    3. Liraglutide modulates GABAergic signaling in rat hippocampal CA3 pyramidal neurons predominantly by presynaptic mechanism
    Open this publication in new window or tab >>Liraglutide modulates GABAergic signaling in rat hippocampal CA3 pyramidal neurons predominantly by presynaptic mechanism
    Show others...
    2017 (English)In: BMC Pharmacology & Toxicology, E-ISSN 2050-6511, Vol. 18, article id 83Article in journal (Refereed) Published
    Abstract [en]

    Background

    γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain where it regulates activity of neuronal networks. The receptor for glucagon-like peptide-1 (GLP-1) is expressed in the hippocampus, which is the center for memory and learning. In this study we examined effects of liraglutide, a GLP-1 analog, on GABA signaling in CA3 hippocampal pyramidal neurons.

    Methods

    We used patch-clamp electrophysiology to record synaptic and tonic GABA-activated currents in CA3 pyramidal neurons in rat hippocampal brain slices.

    Results

    We examined the effects of liraglutide on the neurons at concentrations ranging from one nM to one μM. Significant changes of the spontaneous inhibitory postsynaptic currents (sIPSCs) were only recorded with 100 nM liraglutide and then in just ≈50% of the neurons tested at this concentration. In neurons affected by liraglutide both the sIPSC frequency and the most probable amplitudes increased. When the action potential firing was inhibited by tetrodotoxin (TTX) the frequency and amplitude of IPSCs in TTX and in TTX plus 100 nM liraglutide were similar.

    Conclusions

    The results demonstrate that liraglutide regulation of GABA signaling of CA3 pyramidal neurons is predominantly presynaptic and more limited than has been observed for GLP-1 and exendin-4 in hippocampal neurons.

    Keywords
    GABA, GLP-1 receptor, patch-clamp, inhibitory postsynaptic and tonic currents, hippocampus, electrophysiology
    National Category
    Other Biological Topics Neurosciences Pharmacology and Toxicology
    Research subject
    Neuroscience; Pharmacology; Biology with specialization in Molecular Biology
    Identifiers
    urn:nbn:se:uu:diva-282424 (URN)10.1186/s40360-017-0191-0 (DOI)000418264400001 ()29246184 (PubMedID)
    Projects
    Effect of metabolic hormones on GABA signalling in the hippocampus
    Funder
    Swedish Research CouncilThe Swedish Brain FoundationEXODIAB - Excellence of Diabetes Research in SwedenÅke Wiberg Foundation
    Available from: 2016-04-05 Created: 2016-04-05 Last updated: 2018-02-16Bibliographically approved
  • 11.
    Babateen, Omar M.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Bhandage, Amol K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Korol, Sergiy V.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Westermark, Bengt
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neuro-Oncology.
    Nilsson, Karin Forsberg
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neuro-Oncology.
    Uhrbom, Lene
    Uppsala University, Science for Life Laboratory, SciLifeLab. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neuro-Oncology.
    Smits, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurology.
    GABA-A receptor currents in a cell line (U3047MG) derived from a human glioblastoma tumor are enhanced by etomidate, propofol and diazepam2014In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, no S696, p. 100-100, article id P74Article in journal (Other academic)
  • 12. Backstrom, Tobias
    et al.
    Heynen, Martina
    Brannas, Eva
    Nilsson, Jan
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Magnhagen, Carin
    Social stress effects on pigmentation and monoamines in Arctic charr2015In: Behavioural Brain Research, ISSN 0166-4328, E-ISSN 1872-7549, Vol. 291, p. 103-107Article in journal (Refereed)
    Abstract [en]

    Pigmentation often signals status and in general melanin-based pigmentation is indicative of aggression and stress resilience in vertebrates. This is evident in the salmonids Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) where more melanin spotted individuals are more stress resilient. However, in the salmonid Arctic charr (Salvelinus alpinus) it seems as if it is carotenoid-based pigmentation that signals aggression and stress resilience. In our study, social stress effects on carotenoid-based spots, and behavioural and physiological stress responses were investigated. Socially stressed individuals have more spots, and behavioural stress responses were associated with spots. Some of the results concerning physiological stress responses, such as plasma cortisol levels and monoaminergic activity, are associated with spottiness. Further, the earlier proposed lateralization of spots, with left side connected to stress responsiveness and right side to aggression, is to some extent validated although not conclusively. In conclusion, this study provides further evidence that more stressed charr have more carotenoid spots, and for the first time monoaminergic activity is shown to be connected with carotenoid pigmentation.

  • 13.
    Backstrom, Tobias
    et al.
    Univ Koblenz Landau, Inst Integrated Nat Sci, Koblenz, Germany..
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Serotonin Coordinates Responses to Social Stress: What We Can Learn from Fish2017In: Frontiers in Neuroscience, ISSN 1662-4548, E-ISSN 1662-453X, Vol. 11, article id 595Article, review/survey (Refereed)
    Abstract [en]

    Social interaction is stressful and subordinate individuals are often subjected to chronic stress, which greatly affects both their behavior and physiology. In teleost fish the social position of an individual may have long-term effects, such as effects on migration, age of sexual maturation or even sex. The brain serotonergic system plays a key role in coordinating autonomic, behavioral and neuroendocrine stress responses. Social subordination results in a chronic activation of the brain serotonergic system an effect, which seems to be central in the subordinate phenotype. However, behavioral effects of short-term acute activation of the serotonergic system are less obvious. As in other vertebrates, divergent stress coping styles, often referred to as proactive and reactive, has been described in teleosts. As demonstrated by selective breeding, stress coping styles appear to be partly heritable. However, teleost fish are characterized by plasticity, stress coping style being affected by social experience. Again, the brain serotonergic system appears to play an important role. Studies comparing brain gene expression of fish of different social rank and/or displaying divergent stress coping styles have identified several novel factors that seem important for controlling aggressive behavior and stress coping, e.g., histamine and hypocretin/orexin. These may also interact with brain monoaminergic systems, including serotonin.

  • 14.
    Backström, Tobias
    et al.
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Heynen, Martina
    Dept Ecol & Environm Sci, Umea, Sweden..
    Brännäs, Eva
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Nilsson, Jan
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Magnhagen, Carin
    Swedish Univ Agr Sci, Dept Wildlife Fish & Environm Studies, Umea, Sweden..
    Anaesthesia and handling stress effects on pigmentation and monoamines in Arctic charr2017In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 100, no 5, p. 471-480Article in journal (Refereed)
    Abstract [en]

    Stress responsiveness differs between individuals and is often categorized into different stress coping styles. Using these stress coping styles for selection in fish farming could be beneficial, since stress is one main factor affecting welfare. In Arctic charr (Salvelinus alpinus) carotenoid pigmentation is associated with stress responsiveness and stress coping styles. Thus this could be an important tool to use for selection of stress resilient charr. However, anaesthetics seem to affect carotenoid pigmentation, and it would be better if the method for selection could be implemented during normal maintenance, which usually includes anaesthetics. Therefore, this study investigated how the use of anaesthetics affected carotenoid pigmentation, i.e. number of spots, over time compared to no-anaesthetic treatment. Additionally, the stress indicators monoamines and glucocorticoids were investigated. The results indicate that the anaesthetic MS-222 affects number of spots on the right side. This anaesthetic also increased dopaminergic activity in the telencephalon. Both brain dopaminergic and serotonergic activity was associated with spottiness. Further, behaviour during anaesthetization was associated with spots on the left side, but not the right side. Repetition of the same treatment seemed to affect spot numbers on the right side. In conclusion, this study shows that inducing stress in charr affects the carotenoid spots. Thus, it is possible to use anaesthetics when evaluating spottiness although careful planning is needed.

  • 15.
    Backström, Tobias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Pettersson, Andreas
    Johansson, Viktoria
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    CRF and urotensin I effects on aggression and anxiety-like behavior in rainbow trout2011In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 214, no 6, p. 907-914Article in journal (Refereed)
    Abstract [en]

    Corticotropin-releasing factor (CRF) is central in the stress response but also modulates several behaviors including anxiety-related behaviors and aggression. In this study, juvenile rainbow trout (Oncorhynchus mykiss) were tested for competitive ability, determined during dyadic fights for dominance, after intracerebroventricular (i.c.v.) administration of CRF, urotensin I (UI), the non-specific CRF antagonist alpha-helical RF9-41 (ahCRF) or the CRF receptor subtype 1-specific antagonist antalarmin, when paired with a mass-matched con-specific injected with saline. In addition, isolated fish received the same substances. Plasma cortisol and brain monoamines were monitored in all fish. Most fish receiving CRF showed a conspicuous behavior consisting of flaring the opercula, opening the mouth and violent shaking of the head from side to side. When this occurred, the fish immediately forfeited the fight. Similar behavior was observed in most fish receiving UI but no effect on outcome of dyadic fights was noted. This behavior seems similar to non-ambulatory motor activity seen in rats and could be anxiety related. Furthermore, fish receiving CRF at a dose of 1000. ng became subordinate, whereas all other treatments had no effects on the outcome of dyadic fights. In addition, isolated fish receiving ahCRF had lower brain stem concentrations of 5-hydroxyindoleacetic acid, serotonin, 3,4-dihydroxyphenylacetic acid and dopamine. In conclusion, CRF seems to attenuate competitive ability, and both CRF and UI seem to induce anxiety-like behavior.

  • 16.
    Backström, Tobias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organism Biology, Comparative Physiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Schjolden, Joachim
    Overli, Oyvind
    Thörnqvist, Per-Ove
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Stress effects on AVT and CRF systems in two strains of rainbow trout (Oncorhynchus mykiss) divergent in stress responsiveness2011In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 59, no 1, p. 180-186Article in journal (Refereed)
    Abstract [en]

    The aim for this study was to examine whether the F4 generation of two strains of rainbow trout divergent in their plasma cortisol response to confinement stress (HR: high responder or LR: low responder) would also differ in stress-induced effects on forebrain concentrations of mRNA for corticotropin-releasing factor (CRF). arginine vasotocin (AVT). CRF receptor type 1 (CRF-R1). CRF receptor type 2 (CRF-R2) and AVT receptor (AVT-R). In addition, plasma cortisol concentrations, brainstem levels of monoamines and monoamine metabolites, and behaviour during confinement were monitored. The results confirm that HR and LR trout differ in their cortisol response to confinement and show that fish of these strains also differ in their behavioural response to confinement. The HR trout displayed significantly higher locomotor activity while in confinement than LR trout. Moreover, following 180 min of confinement HR fish showed significantly higher forebrain concentrations of CRF mRNA than LR fish. Also, when subjected to 30 min of confinement HR fish showed significantly lower CRF-R2 mRNA concentrations than LR fish, whereas there were no differences in CRF-R1. AVT or AVT-R mRNA expression between LR and HR fish either at 30 or 180 min of confinement. Differences in the expression of CRF and CRF-R2 mRNA may be related to the divergence in stress coping displayed by these rainbow trout strains.

  • 17.
    Badiali, Luca
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Functional Pharmacology.
    Cedernaes, Jonathan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Functional Pharmacology.
    Olszewski, Pawel K
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Functional Pharmacology.
    Nylander, Olof
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Vergoni, Anna V
    Schiöth, Helgi B
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Functional Pharmacology.
    Adhesion GPCRs are widely expressed throughout the subsections of the gastrointestinal tract2012In: BMC gastroenterology, ISSN 1471-230X, Vol. 12, p. 134-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: G protein-coupled receptors (GPCRs) represent one of the largest families of transmembrane receptors and the most common drug target. The Adhesion subfamily is the second largest one of GPCRs and its several members are known to mediate neural development and immune system functioning through cell-cell and cell-matrix interactions. The distribution of these receptors has not been characterized in detail in the gastrointestinal (GI) tract. Here we present the first comprehensive anatomical profiling of mRNA expression of all 30 Adhesion GPCRs in the rat GI tract divided into twelve subsegments.

    METHODS: Using RT-qPCR, we studied the expression of Adhesion GPCRs in the esophagus, the corpus and antrum of the stomach, the proximal and distal parts of the duodenum, ileum, jejunum and colon, and the cecum.

    RESULTS: We found that twenty-one Adhesion GPCRs (70%) had a widespread (expressed in five or more segments) or ubiquitous (expressed in eleven or more segments) distribution, seven (23%) were restricted to a few segments of the GI tract and two were not expressed in any segment. Most notably, almost all Group III members were ubiquitously expressed, while the restricted expression was characteristic for the majority of group VII members, hinting at more specific/localized roles for some of these receptors.

    CONCLUSIONS: Overall, the distribution of Adhesion GPCRs points to their important role in GI tract functioning and defines them as a potentially crucial target for pharmacological interventions.

  • 18.
    Barnett, Paul D
    et al.
    University of Adelaide.
    Nordström, Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    O'Carroll, David C
    University of Adelaide .
    Motion adaptation and the velocity coding of natural scenes2010In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 20, no 11, p. 994-999Article in journal (Refereed)
    Abstract [en]

    Estimating relative velocity in the natural environment is challenging because natural scenes vary greatly in contrast and spatial structure. Widely accepted correlation-based models for elementary motion detectors (EMDs) are sensitive to contrast and spatial structure and consequently generate ambiguous estimates of velocity [1]. Identified neurons in the third optic lobe of the hoverfly can reliably encode the velocity of natural images largely independent of contrast [2], despite receiving inputs directly from arrays of such EMDs [3, 4]. This contrast invariance suggests an important role for additional neural processes in robust encoding of image motion [2, 5, 6]. However, it remains unclear which neural processes are contributing to contrast invariance. By recording from horizontal system neurons in the hoverfly lobula, we show two activity-dependent adaptation mechanisms acting as near-ideal normalizers for images of different contrasts that would otherwise produce highly variable response magnitudes. Responses to images that are initially weak neural drivers are boosted over several hundred milliseconds. Responses to images that are initially strong neural drivers are reduced over longer time scales. These adaptation mechanisms appear to be matched to higher-order natural image statistics reconciling the neurons' accurate encoding of image velocity with the inherent ambiguity of correlation-based motion detectors.

  • 19. Barragan, A.
    et al.
    Weidner, J. M.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Korpi, E. R.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    GABAergic signalling in the immune system2015In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, no 4, p. 819-827Article, review/survey (Refereed)
    Abstract [en]

    The GABAergic system is the main inhibitory neurotransmitter system in the central nervous system (CNS) of vertebrates. Signalling of the transmitter c-aminobutyric acid (GABA) via GABA type A receptor channels or G-protein-coupled type B receptors is implicated in multiple CNS functions. Recent findings have implicated the GABAergic system in immune cell functions, inflammatory conditions and diseases in peripheral tissues. Interestingly, the specific effects may vary between immune cell types, with stage of activation and be altered by infectious agents. GABA/GABA-A receptor-mediated immunomodulatory functions have been unveiled in immune cells, being present in T lymphocytes and regulating the migration of Toxoplasma-infected dendritic cells. The GABAergic system may also play a role in the regulation of brain resident immune cells, the microglial cells. Activation of microglia appears to regulate the function of GABAergic neurotransmission in neighbouring neurones through changes induced by secretion of brain-derived neurotrophic factor. The neurotransmitter-driven immunomodulation is a new but rapidly growing field of science. Herein, we review the present knowledge of the GABA signalling in immune cells of the periphery and the CNS and raise questions for future research.

  • 20.
    Barrio, Alvaro Martinez
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Ekerljung, Marie
    Jern, Patric
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Benachenhou, Farid
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Sperber, Göran O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Bongcam-Rudloff, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Andersson, Göran
    The First Sequenced Carnivore Genome Shows Complex Host-Endogenous Retrovirus Relationships2011In: PLOS ONE, ISSN 1932-6203, Vol. 6, no 5, p. e19832-Article in journal (Refereed)
    Abstract [en]

    Host-retrovirus interactions influence the genomic landscape and have contributed substantially to mammalian genome evolution. To gain further insights, we analyzed a female boxer (Canis familiaris) genome for complexity and integration pattern of canine endogenous retroviruses (CfERV). Intriguingly, the first such in-depth analysis of a carnivore species identified 407 CfERV proviruses that represent only 0.15% of the dog genome. In comparison, the same detection criteria identified about six times more HERV proviruses in the human genome that has been estimated to contain a total of 8% retroviral DNA including solitary LTRs. These observed differences in man and dog are likely due to different mechanisms to purge, restrict and protect their genomes against retroviruses. A novel group of gammaretrovirus-like CfERV with high similarity to HERV-Fc1 was found to have potential for active retrotransposition and possibly lateral transmissions between dog and human as a result of close interactions during at least 10.000 years. The CfERV integration landscape showed a non-uniform intra-and inter-chromosomal distribution. Like in other species, different densities of ERVs were observed. Some chromosomal regions were essentially devoid of CfERVs whereas other regions had large numbers of integrations in agreement with distinct selective pressures at different loci. Most CfERVs were integrated in antisense orientation within 100 kb from annotated protein-coding genes. This integration pattern provides evidence for selection against CfERVs in sense orientation relative to chromosomal genes. In conclusion, this ERV analysis of the first carnivorous species supports the notion that different mammals interact distinctively with endogenous retroviruses and suggests that retroviral lateral transmissions between dog and human may have occurred.

  • 21.
    Barrio, Alvaro Martínez
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, The Linnaeus Centre for Bioinformatics.
    Lagercrantz, Erik
    Sperber, Göran O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Bongcam-Rudloff, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, The Linnaeus Centre for Bioinformatics.
    Annotation and visualization of endogenous retroviral sequences using the Distributed Annotation System (DAS) and eBioX2009In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 10 Suppl. 6, p. S18-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: The Distributed Annotation System (DAS) is a widely used network protocol for sharing biological information. The distributed aspects of the protocol enable the use of various reference and annotation servers for connecting biological sequence data to pertinent annotations in order to depict an integrated view of the data for the final user. RESULTS: An annotation server has been devised to provide information about the endogenous retroviruses detected and annotated by a specialized in silico tool called RetroTector. We describe the procedure to implement the DAS 1.5 protocol commands necessary for constructing the DAS annotation server. We use our server to exemplify those steps. Data distribution is kept separated from visualization which is carried out by eBioX, an easy to use open source program incorporating multiple bioinformatics utilities. Some well characterized endogenous retroviruses are shown in two different DAS clients. A rapid analysis of areas free from retroviral insertions could be facilitated by our annotations. CONCLUSION: The DAS protocol has shown to be advantageous in the distribution of endogenous retrovirus data. The distributed nature of the protocol is also found to aid in combining annotation and visualization along a genome in order to enhance the understanding of ERV contribution to its evolution. Reference and annotation servers are conjointly used by eBioX to provide visualization of ERV annotations as well as other data sources. Our DAS data source can be found in the central public DAS service repository, http://www.dasregistry.org, or at http://loka.bmc.uu.se/das/sources.

  • 22. Basic, D.
    et al.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Schjolden, J.
    Krogdahl, A.
    Hoglund, E.
    Context-dependent responses to novelty in Rainbow trout (Oncorhynchus mykiss), selected for high and low post-stress cortisol responsiveness2012In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 105, no 5, p. 1175-1181Article in journal (Refereed)
    Abstract [en]

    Previous studies in a rainbow trout model, selectively bred for high (HR) and low (LR) post stress plasma cortisol levels, have yielded data that are indicative of contrasting stress coping styles. Fish from the HR line have been suggested to display a more diverse behavioral repertoire in challenging situations than the LR counterpart. The present study addressed whether such variation in behavioral flexibility traits was evident in different experimental settings using these selection lines. The fish were subjected to three sets of challenges (novel object test, resident-intruder test and confinement stressor test), all which were repeated a week later. Introducing a novel object evoked a divergent behavioral response in association with feeding: fish from the LR line displayed consistently suppressed feed intake while the HR fish remained unaffected. This observation was found to be repeatable along with attack latency and movement activity from the resident-intruder and confinement stressor tests. These results indicate that the behavioral responses in this animal model are context-dependent and shed new light on the expression of behavioral flexibility.

  • 23. Basic, Dean
    et al.
    Krogdahl, Ashild
    Schjolden, Joachim
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Vindas, Marco A.
    Hillestad, Marie
    Mayer, Ian
    Skjerve, Eystein
    Höglund, Erik
    Short- and long-term effects of dietary L-tryptophan supplementation on the neuroendocrine stress response in seawater-reared Atlantic salmon (Salmo salar)2013In: Aquaculture, ISSN 0044-8486, E-ISSN 1873-5622, Vol. 388, p. 8-13Article in journal (Refereed)
    Abstract [en]

    The essential amino acid L-tryptophan (Trp) is the immediate precursor of the neurotransmitter serotonin (5-HT). Supplementing Trp through diet has been shown to suppress the neuroendocrine stress response in vertebrates including teleosts. In salmonid fish, adjusting to the social environment as well as habituation to seawater involves the neuroendocrine stress response, suggesting that such environmental factors may modulate the stress-reducing effects of Trp. To date, studies that have investigated the neuroendocrine effects of dietary Trp have only been conducted in rainbow trout (Oncorhynchus mykiss), a salmonid species, under conditions featuring social isolation in the freshwater environment. Here, we address the effects of dietary Trp on post-stress plasma cortisol and hypothalamic monoamines in seawater-adapted Atlantic salmon (Salmo salar), reared at densities relevant for aquaculture. Fish were given feed containing 1, 2, 3 or 4 times the Trp content in normal feed for one week. Subsequently, the fish were reintroduced to feed containing the lowest Trp level, corresponding to standard commercial feed for a number of days prior to exposure to an acute confinement stressor. Basal plasma cortisol levels were lower among non-stressed fish at 1 and 10 days post dietary Trp supplementation. By comparison, stressed fish displayed stimulatory post-stress plasma cortisol responses at 1 and 2 days after the Trp regimen was terminated. However, a reversed pattern was observed among these fish at 10 days after Trp treatment. The overall effects of dietary Trp were more pronounced in dopamine (DA) neurochemistry compared to 5-HT in the hypothalamus. The results demonstrate both short-and long-term effects of elevated dietary Trp on the neuroendocrine stress response. These findings suggest that hypothalamic DA may be more involved than 5-HT in the stress reducing effects of Trp in seawater-adapted Atlantic salmon, reared at densities relevant for aquaculture.

  • 24. Basic, Dean
    et al.
    Schjolden, Joachim
    Krogdahl, Ashild
    von Krogh, Kristine
    Hillestad, Marie
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Mayer, Ian
    Skjerve, Eystein
    Hoglund, Erik
    Changes in regional brain monoaminergic activity and temporary down-regulation in stress response from dietary supplementation with L-tryptophan in Atlantic cod (Gadus morhua)2013In: British Journal of Nutrition, ISSN 0007-1145, E-ISSN 1475-2662, Vol. 109, no 12, p. 2166-2174Article in journal (Refereed)
    Abstract [en]

    The brain monoamines serotonin (5-hydroxytryptamine; 5-HT) and dopamine (DA) both play an integrative role in behavioural and neuroendocrine responses to challenges, and comparative models suggest common mechanisms for dietary modulation of transmission by these signal substances in vertebrates. Previous studies in teleosts demonstrate that 7 d of dietary administration with L-tryptophan (Trp), the direct precursor of 5-HT, suppresses the endocrine stress response. The present study investigated how long the suppressive effects of a Trp-enriched feed regimen, at doses corresponding to two, three or four times the Trp levels in commercial feed, last in juvenile Atlantic cod (Gadus morhua) when the fish are reintroduced to a diet with standard amino acid composition. We also wanted to determine whether Trp supplementation induced changes in brain monoaminergic neurochemistry in those forebrain structures innervated by DA- and 5-HTergic neurons, by measuring regional activity of DA and 5-HT in the lateral pallial regions (Dl) of the telencephalon and nucleus lateralis tuberis (NLT) of the hypothalamus. Dietary Trp resulted in a dose-dependent suppression in plasma cortisol among fish exposed to confinement stress on the first day following experimental diet; however, such an effect was not observed at 2 or 6 d after Trp treatment. Feeding the fish with moderate Trp doses also evoked a general increase in DA and 5-HT-ergic activity, suggesting that these neural circuits within the NLT and Dl may be indirectly involved in regulating the acute stress response.

  • 25.
    Benachenhou, Farid
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Jern, Patric
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Oja, Merja
    Helsinki University of Technology.
    Sperber, Göran
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Blikstad, Vidar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Somervuo, Panu
    Helsinki Institute for Information Technology, Department of Computer Science, University of Helsinki.
    Kaski, Samuel
    Helsinki Institute for Information Technology, Department of Computer Science, University of Helsinki.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Virology.
    Evolutionary Conservation of Orthoretroviral Long Terminal Repeats (LTRs) and ab initio Detection of Single LTRs in Genomic Data2009In: PLos ONE, ISSN 1932-6203, Vol. 4, no 4, p. e5179-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Retroviral LTRs, paired or single, influence the transcription of both retroviral and non-retroviral genomic sequences. Vertebrate genomes contain many thousand endogenous retroviruses (ERVs) and their LTRs. Single LTRs are difficult to detect from genomic sequences without recourse to repetitiveness or presence in a proviral structure. Understanding of LTR structure increases understanding of LTR function, and of functional genomics. Here we develop models of orthoretroviral LTRs useful for detection in genomes and for structural analysis. PRINCIPAL FINDINGS: Although mutated, ERV LTRs are more numerous and diverse than exogenous retroviral (XRV) LTRs. Hidden Markov models (HMMs), and alignments based on them, were created for HML- (human MMTV-like), general-beta-, gamma- and lentiretroviruslike LTRs, plus a general-vertebrate LTR model. Training sets were XRV LTRs and RepBase LTR consensuses. The HML HMM was most sensitive and detected 87% of the HML LTRs in human chromosome 19 at 96% specificity. By combining all HMMs with a low cutoff, for screening, 71% of all LTRs found by RepeatMasker in chromosome 19 were found. HMM consensus sequences had a conserved modular LTR structure. Target site duplications (TG-CA), TATA (occasionally absent), an AATAAA box and a T-rich region were prominent features. Most of the conservation was located in, or adjacent to, R and U5, with evidence for stem loops. Several of the long HML LTRs contained long ORFs inserted after the second A rich module. HMM consensus alignment allowed comparison of functional features like transcriptional start sites (sense and antisense) between XRVs and ERVs. CONCLUSION: The modular conserved and redundant orthoretroviral LTR structure with three A-rich regions is reminiscent of structurally relaxed Giardia promoters. The five HMMs provided a novel broad range, repeat-independent, ab initio LTR detection, with prospects for greater generalisation, and insight into LTR structure, which may aid development of LTR-targeted pharmaceuticals.

  • 26.
    Benachenhou, Farid
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Virology.
    Sperber, Göran O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Bongcam-Rudloff, Erik
    Andersson, Goran
    Boeke, Jef D.
    Blomberg, Jonas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Microbiology and Infectious Medicine, Clinical Virology.
    Conserved structure and inferred evolutionary history of long terminal repeats (LTRs)2013In: Mobile DNA, ISSN 1759-8753, E-ISSN 1759-8753, Vol. 4, p. 5-Article in journal (Refereed)
    Abstract [en]

    Background: Long terminal repeats (LTRs, consisting of U3-R-U5 portions) are important elements of retroviruses and related retrotransposons. They are difficult to analyse due to their variability. The aim was to obtain a more comprehensive view of structure, diversity and phylogeny of LTRs than hitherto possible. Results: Hidden Markov models (HMM) were created for 11 clades of LTRs belonging to Retroviridae (class III retroviruses), animal Metaviridae (Gypsy/Ty3) elements and plant Pseudoviridae (Copia/Ty1) elements, complementing our work with Orthoretrovirus HMMs. The great variation in LTR length of plant Metaviridae and the few divergent animal Pseudoviridae prevented building HMMs from both of these groups. Animal Metaviridae LTRs had the same conserved motifs as retroviral LTRs, confirming that the two groups are closely related. The conserved motifs were the short inverted repeats (SIRs), integrase recognition signals (5' TGTTRNR ... YNYAACA 3'); the polyadenylation signal or AATAAA motif; a GT-rich stretch downstream of the polyadenylation signal; and a less conserved AT-rich stretch corresponding to the core promoter element, the TATA box. Plant Pseudoviridae LTRs differed slightly in having a conserved TATA-box, TATATA, but no conserved polyadenylation signal, plus a much shorter R region. The sensitivity of the HMMs for detection in genomic sequences was around 50% for most models, at a relatively high specificity, suitable for genome screening. The HMMs yielded consensus sequences, which were aligned by creating an HMM model (a 'Superviterbi' alignment). This yielded a phylogenetic tree that was compared with a Pol-based tree. Both LTR and Pol trees supported monophyly of retroviruses. In both, Pseudoviridae was ancestral to all other LTR retrotransposons. However, the LTR trees showed the chromovirus portion of Metaviridae clustering together with Pseudoviridae, dividing Metaviridae into two portions with distinct phylogeny. Conclusion: The HMMs clearly demonstrated a unitary conserved structure of LTRs, supporting that they arose once during evolution. We attempted to follow the evolution of LTRs by tracing their functional foundations, that is, acquisition of RNAse H, a combined promoter/polyadenylation site, integrase, hairpin priming and the primer binding site (PBS). Available information did not support a simple evolutionary chain of events.

  • 27.
    Bengtsson, Magnus W.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Mäkelä, Kari
    Sjöblom, Markus
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Uotila, Sanna
    Åkerman, Karl E. O.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Herzig, Karl-Heinz
    Flemström, Gunnar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Food-induced expression of orexin receptors in rat duodenal mucosa regulates the bicarbonate secretory response to orexin-A2007In: American Journal of Physiology - Gastrointestinal and Liver Physiology, ISSN 0193-1857, E-ISSN 1522-1547, Vol. 293, no 2, p. G501-G509Article in journal (Refereed)
    Abstract [en]

    Presence of appetite-regulating peptides orexin-A and orexin-B in mucosal endocrine cells suggests a role in physiological control of the intestine. Our aim was to characterize orexin-induced stimulation of duodenal bicarbonate secretion and modulation of secretory responses and mucosal orexin receptors by overnight food deprivation. Lewis x Dark Agouti rats were anesthetized and proximal duodenum cannulated in situ. Mucosal bicarbonate secretion (pH stat) and mean arterial blood pressure were continuously recorded. Orexin-A was administered intra-arterially close to the duodenum, intraluminally, or into the brain ventricles. Total RNA was extracted from mucosal specimens, reverse transcribed to cDNA and expression of orexin receptors 1 and 2 (OX1 and OX2) measured by quantitative real-time PCR. OX1 protein was measured by Western blot. Intra-arterial orexin-A (60–600 nmol·h–1·kg–1) increased (P < 0.01) the duodenal secretion in fed but not in fasted animals. The OX1 receptor antagonist SB-334867, which was also found to have a partial agonist action, abolished the orexin-induced secretory response but did not affect secretion induced by the muscarinic agonist bethanechol. Atropine, in contrast, inhibited bethanechol but not orexin-induced secretion. Orexin-A infused into the brain ventricles (2–20 nmol·kg–1·h–1) or added to luminal perfusate (1.0–100 nM) did not affect secretion, indicating that orexin-A acts peripherally and at basolateral receptors. Overnight fasting decreased mucosal OX1 and OX2 mRNA expression (P < 0.01) as well as OX1 protein expression (P < 0.05). We conclude that stimulation of secretion by orexin-A may involve both receptor types and is independent of cholinergic pathways. Intestinal OX receptors and secretory responses are markedly related to food intake.

  • 28.
    Berg, Cecilia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Backström, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Comparative Physiology.
    Winberg, Svante
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Lindberg, Richard
    Brandt, Ingvar
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental toxicology.
    Developmental Exposure to Fluoxetine Modulates the Serotonin System in Hypothalamus2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 1, p. e55053-Article in journal (Refereed)
    Abstract [en]

    The selective serotonin reuptake inhibitor (SSRI) fluoxetine (FLU, Prozac (R)) is commonly prescribed for depression in pregnant women. This results in SSRI exposure of the developing fetus. However, there are knowledge gaps regarding the impact of SSRI exposure during development. Given the role of serotonin in brain development and its cross-talk with sex hormone function, we investigated effects of developmental exposure to pharmacologically relevant concentrations of FLU (3 and 30 nM (measured)) on brain neurotransmitter levels, gonadal differentiation, aromatase activity in brain and gonads, and the thyroid system, using the Xenopus tropicalis model. Tadpoles were chronically exposed (8 weeks) until metamorphosis. At metamorphosis brains were cryosectioned and levels of serotonin, dopamine, norepinephrine, and their metabolites 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic acid, and homovanillic acid were measured in discrete regions (telencephalon, hypothalamus and the reticular formation) of the cryosections using high-performance liquid chromatography. Exposure to 30 nM FLU increased the concentration of 5-hydroxyindoleacetic acid in hypothalamus compared with controls. FLU exposure did not affect survival, time to metamorphosis, thyroid histology, gonadal sex differentiation, or aromatase activity implying that the effect on the serotonergic neurotransmitter system in the hypothalamus region was specific. The FLU concentration that impacted the serotonin system is lower than the concentration measured in umbilical cord serum, suggesting that the serotonin system of the developing brain is highly sensitive to in utero exposure to FLU. To our knowledge this is the first study showing effects of developmental FLU exposure on brain neurochemistry. Given that SSRIs are present in the aquatic environment the current results warrant further investigation into the neurobehavioral effects of SSRIs in aquatic wildlife.

  • 29.
    Bhandage, Amol
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Hellgren, Charlotte
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Ólafsson, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Sundström Poromaa, Inger
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Obstetrics and Gynaecology.
    Birnir, Bryndis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    The mRNA expression of GABA-A, GABA-B receptor subunits and chloride transporters in peripheral blood mononuclear cells is influenced by gender, pregnancy and depression2015In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 215, p. 91-91Article in journal (Other academic)
  • 30.
    Bhandage, Amol K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Glutamate and GABA signalling components in the human brain and in immune cells2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Glutamate and γ-aminobutyric acid (GABA) are the principal excitatory and inhibitory neurotransmitters in the central nervous system (CNS). They both can activate their ionotropic and metabotropic receptors. Glutamate activates ionotropic glutamate receptors (iGlu - AMPA, kainate and NMDA receptors) and GABA activates GABA-A receptors which are modulated by many types of drugs and substances including alcohol. Using real time quantitative polymerase chain reaction, I have shown that iGlu and/or GABA-A receptor subunits were expressed in the hippocampus dentate gyrus (HDG), orbitofrontal cortex (OFC), dorsolateral prefrontal cortex (DL-PFC), central amygdala (CeA), caudate and putamen of the human brain and their expression was altered by chronic excessive alcohol consumption. It indicates that excitatory and inhibitory neurotransmission may have been altered in the brain of human alcoholics. It is possible that changes in one type of neurotransmitter system may drive changes in another. These brain regions also play a role in brain reward system. Any changes in them may lead to changes in the normal brain functions.

    Apart from the CNS, glutamate and GABA are also present in the blood and can be synthesised by pancreatic islet cells and immune cells. They may act as immunomodulators of circulating immune cells and can affect immune function through glutamate and GABA receptors. I found that T cells from human, rat and mouse lymph nodes expressed the mRNAs and proteins for specific GABA-A receptor subunits. GABA-evoked transient and tonic currents recorded using the patch clamp technique demonstrate the functional GABA-A channel in T cells. Furthermore, the mRNAs for specific iGlu, GABA-A and GABA-B receptor subunits and chloride cotransporters were detected in peripheral blood mononuclear cells (PBMCs) from men, non-pregnant women, healthy and depressed pregnant women. The results indicate that the expression of iGlu, GABA-A and GABA-B receptors is related to gender, pregnancy and mental health and support the notion that glutamate and GABA receptors may modulate immune function. Intra- and interspecies variability exists in the expression and it is further influenced by physiological conditions.

    List of papers
    1. Selective increases of AMPA, NMDA, and kainate receptor subunit mRNAs in the hippocampus and orbitofrontal cortex but not in prefrontal cortex of human alcoholics
    Open this publication in new window or tab >>Selective increases of AMPA, NMDA, and kainate receptor subunit mRNAs in the hippocampus and orbitofrontal cortex but not in prefrontal cortex of human alcoholics
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    2014 (English)In: Frontiers in Cellular Neuroscience, ISSN 1662-5102, E-ISSN 1662-5102, Vol. 8, p. 11-Article in journal (Refereed) Published
    Abstract [en]

    Glutamate is the main excitatory transmitter in the human brain. Drugs that affect the glutamatergic signaling will alter neuronal excitability. Ethanol inhibits glutamate receptors. We examined the expression level of glutamate receptor subunit mRNAs in human post-mortem samples from alcoholics and compared the results to brain samples from control subjects. RNA from hippocampal dentate gyrus (HP-DG), orbitofrontal cortex (OFC), and dorso-lateral prefrontal cortex (DL-PFC) samples from 21 controls and 19 individuals with chronic alcohol dependence were included in the study. Total RNA was assayed using quantitative RT-PCR. Out of the 16 glutamate receptor subunits, mRNAs encoding two AMPA [2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid] receptor subunits GluA2 and GluA3; three kainate receptor subunits GluK2, GluK3 and GluK5 and five NMDA (N-methyl-D-aspartate) receptor subunits GluN1, GluN2A, GluN2C, GluN2D, and GluN3A were significantly increased in the HP-DG region in alcoholics. In the OFC, mRNA encoding the NMDA receptor subunit GluN3A was increased, whereas in the DL-PFC, no differences in mRNA levels were observed. Our laboratory has previously shown that the expression of genes encoding inhibitory GABA-A receptors is altered in the HP-DG and OFC of alcoholics (Jin et al., 2011). Whether the changes in one neurotransmitter system drives changes in the other or if they change independently is currently not known. The results demonstrate that excessive long-term alcohol consumption is associated with altered expression of genes encoding glutamate receptors in a brain region-specific manner. It is an intriguing possibility that genetic predisposition to alcoholism may contribute to these gene expression changes.

    National Category
    Physiology Neurosciences
    Identifiers
    urn:nbn:se:uu:diva-219489 (URN)10.3389/fncel.2014.00011 (DOI)000331053400001 ()24523671 (PubMedID)
    Available from: 2014-03-03 Created: 2014-03-03 Last updated: 2018-01-11Bibliographically approved
    2. Expression of specific ionotropic glutamate and GABA-A receptor subunits is decreased in central amygdala of alcoholics
    Open this publication in new window or tab >>Expression of specific ionotropic glutamate and GABA-A receptor subunits is decreased in central amygdala of alcoholics
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    2014 (English)In: Frontiers in Cellular Neuroscience, ISSN 1662-5102, E-ISSN 1662-5102, Vol. 8, p. 288-Article in journal (Refereed) Published
    Abstract [en]

    The central amygdala (CeA) has a role for mediating fear and anxiety responses. It is also involved in emotional imbalance caused by alcohol abuse and dependence and in regulating relapse to alcohol abuse. Growing evidences suggest that excitatory glutamatergic and inhibitory gamma-aminobutyric acid-ergic (GABAergic) transmissions in the CeA are affected by chronic alcohol exposure. Human post-mortem CeA samples from male alcoholics (n = 9) and matched controls (n = 9) were assayed for the expression level of ionotropic glutamate and GABA-A receptors subunit mRNAs using quantitative real-time reverse transcription-PCB (RT-qPCR). Our data revealed that out of the 16 ionotropic glutamate receptor subunits, mRNAs encoding two AMPA P-amino-3-(3-hydroxy-5-methyl-isoxazol-4-y1)propanoic acid] receptor subunits GluA1 and GluA4; one kainate receptor subunit GluK2; one NMDA (N-methyl-D-aspartate) receptor subunit GluN2D and one delta receptor subunit GluD2 were significantly decreased in the CeA of alcoholics. In contrast, of the 19 GABA-A receptor subunits, only the mRNA encoding the a2 subunit was significantly down-regulated in the CeA of the alcoholics as compared with control subjects. Our findings imply that the down-regulation of specific ionotropic glutamate and GABA-A receptor subunits in the CeA of alcoholics may represent one of the molecular substrates underlying the new balance between excitatory and inhibitory neurotransmission in alcohol dependence.

    National Category
    Neurosciences
    Identifiers
    urn:nbn:se:uu:diva-239603 (URN)10.3389/fncel.2014.00288 (DOI)000344465400002 ()
    Available from: 2014-12-30 Created: 2014-12-29 Last updated: 2018-01-11Bibliographically approved
    3.
    The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.
    4. Different subtypes of GABA-A receptors are expressed in human, mouse and rat T lymphocytes
    Open this publication in new window or tab >>Different subtypes of GABA-A receptors are expressed in human, mouse and rat T lymphocytes
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, p. e42959-Article in journal (Refereed) Published
    Abstract [en]

    γ-aminobutyric acid (GABA) is the most prominent neuroinhibitory transmitter in the brain, where it activates neuronalGABA-A receptors (GABA-A channels) located at synapses and outside of synapses. The GABA-A receptors are primarytargets of many clinically useful drugs. In recent years, GABA has been shown to act as an immunomodulatory molecule. Wehave examined in human, mouse and rat CD4+ and CD8+ T cells which subunit isoforms of the GABA-A channels areexpressed. The channel physiology and drug specificity is dictated by the GABA-A receptor subtype, which in turn isdetermined by the subunit isoforms that make the channel. There were 5, 8 and 13 different GABA-A subunit isoformsidentified in human, mouse and rat CD4+ and CD8+ T cells, respectively. Importantly, the γ2 subunit that imposesbenzodiazepine sensitivity on the GABA-A receptors, was only detected in the mouse T cells. Immunoblots andimmunocytochemistry showed abundant GABA-A channel proteins in the T cells from all three species. GABA-activatedwhole-cell transient and tonic currents were recorded. The currents were inhibited by picrotoxin, SR95531 and bicuculline,antagonists of GABA-A channels. Clearly, in both humans and rodents T cells, functional GABA-A channels are expressed butthe subtypes vary. It is important to bear in mind the interspecies difference when selecting the appropriate animal modelsto study the physiological role and pharmacological properties of GABA-A channels in CD4+ and CD8+ T cells and whenselecting drugs aimed at modulating the human T cells function.

    National Category
    Neurosciences
    Identifiers
    urn:nbn:se:uu:diva-172532 (URN)10.1371/journal.pone.0042959 (DOI)000307789700016 ()
    Available from: 2012-04-11 Created: 2012-04-11 Last updated: 2018-01-12Bibliographically approved
    5. Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health
    Open this publication in new window or tab >>Expression of GABA receptors subunits in peripheral blood mononuclear cells is gender dependent, altered in pregnancy and modified by mental health
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    2015 (English)In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 213, no 3, p. 575-585Article in journal (Refereed) Published
    Abstract [en]

    AIM: The concept of nerve-driven immunity recognizes a link between the nervous and the immune system. γ-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain and receptors activated by GABA can be expressed by immune cells. Here we examined if the expression of GABA receptors and chloride transporters in human peripheral mononuclear cells (PBMCs) were influenced by gender, pregnancy or mental health.

    METHODS: We used RT-qPCR to determine the mRNA expression level in men (n=16), non-pregnant women (n=19), healthy pregnant women (n=27) and depressed pregnant women (n=15).

    RESULTS: The ρ2 subunit had the most prominent expression level of the GABA-A receptor subunits in all samples. The δ and ρ2 subunits were up-regulated by pregnancy whereas the ε subunit was more frequently expressed in healthy pregnant women than non-pregnant women who, in-turn, commonly expressed the α6 and the γ2 subunits. The β1 and ε subunits expression was altered by depression in pregnant women. The GABA-B1 receptor was up-regulated by depression in pregnant women while the transporters NKCC1 and KCC4 were down-regulated by pregnancy. The changes recorded in the mRNA expression levels imply participation of GABA receptors in establishing and maintaining tolerance in pregnancy. Importantly, the correlation of mental health with the expression of specific receptor subunits reveals a connection between the immune cells and the brain. Biomarkers for mental health may be identified in PBMCs.

    CONCLUSION: The results demonstrate the impact gender, pregnancy and mental health have on expression of GABA receptors plus chloride transporters expressed in human PBMCs.

    National Category
    Physiology
    Identifiers
    urn:nbn:se:uu:diva-240372 (URN)10.1111/apha.12440 (DOI)000348531600007 ()25529063 (PubMedID)
    Available from: 2015-01-07 Created: 2015-01-07 Last updated: 2018-01-11
    6. AMPA, NMDA and kainate glutamate receptor subunits are expressed in human peripheral blood mononuclear cells (PBMCs) where the expression of GluK4 is altered by pregnancy and GluN2D by depression in pregnant women
    Open this publication in new window or tab >>AMPA, NMDA and kainate glutamate receptor subunits are expressed in human peripheral blood mononuclear cells (PBMCs) where the expression of GluK4 is altered by pregnancy and GluN2D by depression in pregnant women
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    2017 (English)In: Journal of Neuroimmunology, ISSN 0165-5728, E-ISSN 1872-8421, Vol. 305, p. 51-58Article in journal (Refereed) Published
    Abstract [en]

    The amino acid glutamate opens cation permeable ion channels, the iGlu receptors. These ion channels are abundantly expressed in the mammalian brain where glutamate is the main excitatory neurotransmitter. The neurotransmitters and their receptors are being increasingly detect