Browsing by Subject "GLUTAMATE"

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  • Harjuhaahto, Sandra; Rasila, Tiina S.; Molchanova, Svetlana M.; Woldegebriel, Rosa; Kvist, Jouni; Konovalova, Svetlana; Sainio, Markus T.; Pennonen, Jana; Torregrosa-Munumer, Ruben; Ibrahim, Hazem; Otonkoski, Timo; Taira, Tomi; Ylikallio, Emil; Tyynismaa, Henna (2020)
    Mitochondrial intermembrane space proteins CHCHD2 and CHCHD10 have roles in motor neuron diseases such as amyotrophic lateral sclerosis, spinal muscular atrophy and axonal neuropathy and in Parkinson's disease. They form a complex of unknown function. Here we address the importance of these two proteins in human motor neurons. We show that gene edited human induced pluripotent stem cells (iPSC) lacking either CHCHD2 or CHCHD10 are viable and can be differentiated into functional motor neurons that fire spontaneous and evoked action potentials. Mitochondria in knockout iPSC and motor neurons sustain ultrastructure but show increased proton leakage and respiration, and reciprocal compensatory increases in CHCHD2 or CHCHD10. Knockout motor neurons have largely overlapping transcriptome profiles compared to isogenic control line, in particular for synaptic gene expression. Our results show that the absence of either CHCHD2 or CHCHD10 alters mitochondrial respiration in human motor neurons, inducing similar compensatory responses. Thus, pathogenic mechanisms may involve loss of synaptic function resulting from defective energy metabolism.
  • Tynkkynen, Juho; Chouraki, Vincent; van der Lee, Sven J.; Hernesniemi, Jussi; Yang, Qiong; Li, Shuo; Beiser, Alexa; Larson, Martin G.; Sääksjärvi, Katri; Shipley, Martin J.; Singh-Manoux, Archana; Gerszten, Robert E.; Wang, Thomas J.; Havulinna, Aki S.; Würtz, Peter; Fischer, Krista; Demirkan, Ayse; Ikram, M. Arfan; Amin, Najaf; Lehtimäki, Terho; Kähönen, Mika; Perola, Markus; Metspalu, Andres; Kangas, Antti J.; Soininen, Pasi; Ala-Korpela, Mika; Vasan, Ramachandran S.; Kivimäki, Mika; van Duijn, Cornelia M.; Seshadri, Sudha; Salomaa, Veikko (2018)
    Introduction: Metabolite, lipid, and lipoprotein lipid profiling can provide novel insights into mechanisms underlying incident dementia and Alzheimer's disease. Methods: We studied eight prospective cohorts with 22,623 participants profiled by nuclear magnetic resonance or mass spectrometry metabolomics. Four cohorts were used for discovery with replication undertaken in the other four to avoid false positives. For metabolites that survived replication, combined association results are presented. Results: Over 246,698 person-years, 995 and 745 cases of incident dementia and Alzheimer's disease were detected, respectively. Three branched-chain amino acids (isoleucine, leucine, and valine), creatinine and two very low density lipoprotein (VLDL)-specific lipoprotein lipid subclasses were associated with lower dementia risk. One high density lipoprotein (HDL; the concentration of cholesterol esters relative to total lipids in large HDL) and one VLDL (total cholesterol to total lipids ratio in very large VLDL) lipoprotein lipid subclass was associated with increased dementia risk. Branched-chain amino acids were also associated with decreased Alzheimer's disease risk and the concentration of cholesterol esters relative to total lipids in large HDL with increased Alzheimer's disease risk. Discussion: Further studies can clarify whether these molecules play a causal role in dementia pathogenesis or are merely markers of early pathology. (C) 2018 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.
  • Aitta-aho, Teemu; Maksimovic, Milica; Dahl, Kristiina; Sprengel, Rolf; Korpi, Esa R. (2019)
    Gene-targeted mice with deficient AMPA receptor GluA1 subunits (Gria1-/- mice) show robust hyperlocomotion in a novel environment, suggesting them to constitute a model for hyperactivity disorders such as mania, schizophrenia and attention deficit hyperactivity disorder. This behavioral alteration has been associated with increased neuronal activation in the hippocampus, and it can be attenuated by chronic treatment with antimanic drugs, such as lithium, valproic acid, and lamotrigine. Now we found that systemic cannabidiol strongly blunted the hyperactivity and the hippocampal c-Fos expression of the Gria1-/- mice, while not affecting the wild-type littermate controls. Acute bilateral intra-dorsal hippocampal infusion of cannabidiol partially blocked the hyperactivity of the Gria1-/- mice, but had no effect on wild-types. The activation of the inhibitory DREADD receptor hM4Gi in the dorsal hippocampus by clozapine-N-oxide robustly inhibited the hyperactivity of the Gria1-/- mice, but had no effect on the locomotion of wild-type mice. Our results show that enhanced neuronal excitability in the hippocampus is associated with pronounced novelty-induced hyperactivity of GluA1 subunit-deficient mice. When this enhanced response of hippocampal neurons to novel stimuli is specifically reduced in the hippocampus by pharmacological treatment or by chemogenetic inhibition, Gria1-/- mice recover from behavioral hyperactivity, suggesting a hippocampal dysfunction in hyperactive behaviors that can be treated with cannabidiol.
  • Veronese, N.; Sergi, G.; Stubbs, B.; Bourdel-Marchasson, I.; Tessier, D.; Sieber, C.; Strandberg, T.; Gillain, S.; Barbagallo, M.; Crepaldi, G.; Maggi, S.; Manzato, E.; EUGMS Special Interest Grp Diabet (2017)
    Background/aim: Deficiency of acetyl-L-carnitine (ALC) and L-carnitine (LC) appears to play a role in peripheral diabetic neuropathy, although the evidence in humans is still limited. We conducted a systematic review and meta-analysis investigating the effect of ALC on pain and electromyographic parameters in people with diabetic neuropathy. Methods: A literature search in major databases, without language restriction, was undertaken. Eligible studies were randomized controlled trials (RCTs) or pre-and post-test studies. The effect of ALC supplementation on pain perception and electromyographic parameters in patients with diabetic neuropathy was compared vs. a control group (RCTs). The effect of ALC/LC on electromyographic parameters were also calculated vs. baseline values. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used for summarizing outcomes. Results: Six articles, with a total of 711 diabetic participants, were included. Three RCTs (340 treated with ALC vs. 203 placebo and 115 with methylcobalamine) showed that ALC reduces pain perception (SMD = -0.45; 95% CI: -0.86 to -0.04; P = 0.03; I-2 = 85%). Compared to controls, ALC supplementation improved nerve conduction velocity and amplitude response for ulnar nerve (both sensory and motor component). Compared to baseline values, ALC/LC supplementation improved nerve conduction velocity for all the sensory and motor nerves (except ulnar and peroneal) investigated and the amplitude of all nerves. The onset of adverse events was generally limited to minor side effects. Conclusion: ALC appears to be effective in reducing pain due to diabetic neuropathy compared to active or placebo controls and improving electromyographic parameters in these patients. (C) 2017 Elsevier Masson SAS and European Union Geriatric Medicine Society. All rights reserved.
  • Leopold, Anna V.; Shcherbakova, Daria; Verkhusha, Vladislav V. (2019)
    Understanding how neuronal activity patterns in the brain correlate with complex behavior is one of the primary goals of modern neuroscience. Chemical transmission is the major way of communication between neurons, however, traditional methods of detection of neurotransmitter and neuromodulator transients in mammalian brain lack spatiotemporal precision. Modern fluorescent biosensors for neurotransmitters and neuromodulators allow monitoring chemical transmission in vivo with millisecond precision and single cell resolution. Changes in the fluorescent biosensor brightness occur upon neurotransmitter binding and can be detected using fiber photometry, stationary microscopy and miniaturized head-mounted microscopes. Biosensors can be expressed in the animal brain using adeno-associated viral vectors, and their cell-specific expression can be achieved with Cre-recombinase expressing animals. Although initially fluorescent biosensors for chemical transmission were represented by glutamate biosensors, nowadays biosensors for GABA, acetylcholine, glycine, norepinephrine, and dopamine are available as well. In this review, we overview functioning principles of existing intensiometric and ratiometric biosensors and provide brief insight into the variety of neurotransmitter-binding proteins from bacteria, plants, and eukaryotes including G-protein coupled receptors, which may serve as neurotransmitter-binding scaffolds. We next describe a workflow for development of neurotransmitter and neuromodulator biosensors. We then discuss advanced setups for functional imaging of neurotransmitter transients in the brain of awake freely moving animals. We conclude by providing application examples of biosensors for the studies of complex behavior with the single-neuron precision.
  • Jacobsen, Kaya K.; Nievergelt, Caroline M.; Zayats, Tetyana; Greenwood, Tiffany A.; Anttila, Verneri; Akiskal, Hagop S.; Haavik, Jan; Fasmer, Ole Bernt; Kelsoe, John R.; Johansson, Stefan; Oedegaard, Ketil J.; BiGs Consortium IHG Consortium; Liu, Chengyu; Wedenoja, Juho Olavi; Kaunisto, Mari Anneli; Heikkilä, Kauko Veli; Kaprio, Jaakko Arthur; Wessman, Maija; Kallela, Mikko; Färkkilä, Markus; Artto, Ville; Eriksson, Johan; Palotie, Aarno Veikko; Daly, Mark (2015)
  • Nagaeva, Elina; Zubarev, Ivan; Gonzales, Carolina Bengtsson; Forss, Mikko; Nikouei, Kasra; de Miguel, Elena; Elsilä, Lauri; Linden, Anni-Maija; Hjerling-Leffler, Jens; Augustine, George J.; Korpi, Esa R. (2020)
    The cellular architecture of the ventral tegmental area (VTA), the main hub of the brain reward system, remains only partially characterized. To extend the characterization to inhibitory neurons, we have identified three distinct subtypes of somatostatin (Sst)-expressing neurons in the mouse VTA. These neurons differ in their electrophysiological and morphological properties, anatomical localization, as well as mRNA expression profiles. Importantly, similar to cortical Sst-containing interneurons, most VTA Sst neurons express GABAergic inhibitory markers, but some of them also express glutamatergic excitatory markers and a subpopulation even express dopaminergic markers. Furthermore, only some of the proposed marker genes for cortical Sst neurons were expressed in the VTA Sst neurons. Physiologically, one of the VTA Sst neuron subtypes locally inhibited neighboring dopamine neurons. Overall, our results demonstrate the remarkable complexity and heterogeneity of VTA Sst neurons and suggest that these cells are multifunctional players in the midbrain reward circuitry.
  • Marzabani, Rezvan; Rezadoost, Hassan; Choopanian, Peyman; Kolahdooz, Sima; Mozafari, Nikoo; Mirzaie, Mehdi; Karimi, Mehrdad; Nieminen, Anni; Jafari, Mohieddin (2021)
    Introduction Vitiligo pathogenesis is complicated, and several possibilities were suggested. However, it is well-known that the metabolism of pigments plays a significant role in the pathogenicity of the disease. Objectives We explored the role of amino acids in vitiligo using targeted metabolomics. Methods The amino acid profile was studied in plasma using liquid chromatography. First, 22 amino acids were derivatized and precisely determined. Next, the concentrations of the amino acids and the molar ratios were calculated in 31 patients and 34 healthy individuals. Results The differential concentrations of amino acids were analyzed and eight amino acids, i.e., cysteine, arginine, lysine, ornithine, proline, glutamic acid, histidine, and glycine were observed differentially. The ratios of cysteine, glutamic acid, and proline increased significantly in Vitiligo patients, whereas arginine, lysine, ornithine, glycine, and histidine decreased significantly compared to healthy individuals. Considering the percentage of skin area, we also showed that glutamic acid significantly has a higher amount in patients with less than 25% involvement compared to others. Finally, cysteine and lysine are considered promising candidates for diagnosing and developing the disorder with high accuracy (0.96). Conclusion The findings are consistent with the previously illustrated mechanism of Vitiligo, such as production deficiency in melanin and an increase in immune activity and oxidative stress. Furthermore, new evidence was provided by using amino acids profile toward the pathogenicity of the disorder.
  • Tiihonen, Jari; Koskuvi, Marja; Lähteenvuo, Markku; Trontti, Kalevi; Ojansuu, Ilkka; Vaurio, Olli; Cannon, D. Tyrone; Lönnqvist, Jouko; Therman, Sebastian; Suvisaari, Jaana; Cheng, Lesley; Tanskanen, Antti; Taipale, Heidi; Lehtonen, Sarka; Koistinaho, Jari (2021)
    The molecular pathophysiological mechanisms underlying schizophrenia have remained unknown, and no treatment exists for primary prevention. We used Ingenuity Pathway Analysis to analyze canonical and causal pathways in two different datasets, including patients from Finland and USA. The most significant findings in canonical pathway analysis were observed for glutamate receptor signaling, hepatic fibrosis, and glycoprotein 6 (GP6) pathways in the Finnish dataset, and GP6 and hepatic fibrosis pathways in the US dataset. In data-driven causal pathways, ADCYAP1, ADAMTS. and CACNA genes were involved in the majority of the top 10 pathways differentiating patients and controls in both Finnish and US datasets. Results from a Finnish nation-wide database showed that the risk of schizophrenia relapse was 41% lower among first-episode patients during the use of losartan, the master regulator of an ADCYAP1, ADAM'S, and CACNA -related pathway, compared to those time periods when the same individual did not use the drug. The results from the two independent datasets suggest that the GP6 signaling pathway, and the ADCYAPI, ADAATTS, and CACNA-related purine, oxidative stress, and glutamatergic signaling pathways are among primary pathophysiological alterations in schizophrenia among patients with European ancestry. While no reproducible dopaminergic alterations were observed, the results imply that agents such as losartan, and ADCYAP1/PACAP -deficit alleviators, such as metabotropic glutamate 2/3 agonise MGS0028 and 5-HT7 antagonists-which have shown beneficial effects in an experimental Adcyapl(-/-) mouse model for schizophrenia - could be potential treatments even before the full manifestation of illness involving dopaminergic abnormalities. (C) 2021 The Authors. Published by Elsevier B.V.
  • Heininen, Juho; Julku, Ulrika; Myöhänen, Timo; Kotiaho, Tapio; Kostiainen, Risto (2021)
    We developed a new multiplexed reversed phase liquid chromatography-high resolution tandem mass spectrometric (LC-MS/MS) method. The method is based on isobaric labeling with a tandem mass tag (TMT10-plex) and stable isotope-labeled internal standards, and was used to analyze amino acids in mouse brain microdialysis samples. The TMT10-plex labeling of amino acids allowed analysis of ten samples in one LC-MS/MS run, significantly increasing the sample throughput. The method provides good chromatographic performance (peak half-width between 0.04-0.12 min), allowing separation of all TMTlabeled amino acids with acceptable resolution and high sensitivity (limits of detection typically around 10 nM). The use of stable isotope-labeled internal standards, together with TMT10-plex labeling, ensured good repeatability (relative standard deviation 0.994), indicating good quantitative performance of the multiplexed method. The method was applied to study the effect of d-amphetamine microdialysis perfusion on amino acid concentrations in the mouse brain. All amino acids were reliably detected and quantified, indicating that the method is sensitive enough to detect low concentrations of amino acids in brain microdialysis samples. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license ( )
  • Ramanathan, Jayendrakishore Tanjore; Lehtipuro, Suvi; Sihto, Harri; Tovari, Jozsef; Reiniger, Lilla; Teglasi, Vanda; Moldvay, Judit; Nykter, Matti; Haapasalo, Hannu; Le Joncour, Vadim; Laakkonen, Pirjo (2020)
    Glioblastomas and brain metastases (BM) of solid tumours are the most common central nervous system neoplasms associated with very unfavourable prognosis. In this study, we report the association of prostate-specific membrane antigen (PSMA) with various clinical parameters in a large cohort of primary and secondary brain tumours. A tissue microarray containing 371 cases of ascending grades of gliomas pertaining to astrocytic origin and samples of 52 cases of primary lung carcinomas with matching BM with follow-up time accounting to 10.4 years was evaluated for PSMA expression using immunohistochemistry. In addition, PSMA expression was studied in BM arising from melanomas and breast carcinomas. Neovascular expression of PSMA was evident alongside with high expression in the proliferating microvasculature of glioblastomas when compared to the tumour cell expression. This result correlated with the results obtained from the in silico (cancer genome databases) analyses. In gliomas, only the vascular expression of PSMA associated with poor overall survival but not the tumour cell expression. In the matched primary lung cancers and their BM (n = 52), vascular PSMA expression in primary tumours associated with significantly accelerated metastatic dissemination to the brain with a tendency towards poor overall survival. Taken together, we report that the vascular expression of PSMA in the primary and secondary brain tumours globally associates with the malignant progression and poor outcome of the patients.
  • Ottka, Claudia; Weber, Corinna; Mueller, Elisabeth; Lohi, Hannes (2021)
    Introduction Phenobarbital is a commonly used anticonvulsant for the treatment of canine epileptic seizures. In addition to its central nervous system (CNS) depressing effects, long-term phenobarbital administration affects liver function. However, broader metabolic consequences of phenobarbital treatment are poorly characterized. Objectives To identify metabolic changes in the sera of phenobarbital-treated dogs and to investigate the relationship between serum phenobarbital concentration and metabolite levels. Methods Leftovers of clinical samples were used: 58 cases with phenobarbital concentrations ranging from 7.8 mu g/mL to 50.8 mu g/mL, and 25 controls. The study design was cross-sectional. The samples were analyzed by a canine-specific H-1 NMR metabolomics platform. Differences between the case and control groups were evaluated by logistic regression. The linear relationship between metabolite and phenobarbital concentrations was evaluated using linear regression. Results Increasing concentrations of glycoprotein acetyls, LDL particle size, palmitic acid, and saturated fatty acids, and decreasing concentrations of albumin, glutamine, histidine, LDL particle concentration, multiple HDL measures, and polyunsaturated fatty acids increased the odds of the sample belonging to the phenobarbital-treated group, having a p-value <.0033, and area under the curve (AUC) > .7. Albumin and glycoprotein acetyls had the best discriminative ability between the groups (AUC: .94). No linear associations between phenobarbital and metabolite concentrations were observed. Conclusion The identified metabolites are known to associate with, for example, liver and CNS function, inflammatory processes and drug binding. The lack of a linear association to phenobarbital concentration suggests that other factors than the blood phenobarbital concentration contribute to the magnitude of metabolic changes.
  • Zhurakovskaya, Ekaterina; Leikas, Juuso; Pirttimaki, Tiina; Mon, Francesc Casas; Gynther, Mikko; Aliev, Rubin; Rantamaki, Tomi; Tanila, Heikki; Forsberg, Markus M.; Gröhn, Olli; Paasonen, Jaakko; Jalkanen, Aaro J. (2019)
    Parkinson's disease (PD) is characterized by the gradual degeneration of dopaminergic neurons in the substantia nigra, leading to striatal dopamine depletion. A partial unilateral striatal 6-hydroxydopamine (6-OHDA) lesion causes 40-60% dopamine depletion in the lesioned rat striatum, modeling the early stage of PD. In this study, we explored the connectivity between the brain regions in partially 6-OHDA lesioned male Wistar rats under urethane anesthesia using functional magnetic resonance imaging (fMRI) at 5 weeks after the 6-OHDA infusion. Under urethane anesthesia, the brain fluctuates between the two states, resembling rapid eye movement (REM) and non-REM sleep states. We observed clear urethane-induced sleep-like states in 8/19 lesioned animals and 8/18 control animals. 6-OHDA lesioned animals exhibited significantly lower functional connectivity between the brain regions. However, we observed these differences only during the REM-like sleep state, suggesting the involvement of the nigrostriatal dopaminergic pathway in REM sleep regulation. Corticocortical and corticostriatal connections were decreased in both hemispheres, reflecting the global effect of the lesion. Overall, this study describes a promising model to study PD-related sleep disorders in rats using fMRI.
  • Kesaf, Sebnem; Khirug, Stanislav; Dinh, Emilie; Saez Garcia, Marta; Soni, Shetal; Orav, Ester; Delpire, Eric; Taira, Tomi; Lauri, Sari E.; Rivera, Claudio (2020)
    Kainate receptors (KAR) play a crucial role in the plasticity and functional maturation of glutamatergic synapses. However, how they regulate structural plasticity of dendritic spines is not known. The GluK2 subunit was recently shown to coexist in a functional complex with the neuronal K-Cl cotransporter KCC2. Apart from having a crucial role in the maturation of GABAergic transmission, KCC2 has a morphogenic role in the maturation of dendritic spines. Here, we show thatin vivolocal inactivation of GluK2 expression in CA3 hippocampal neurons induces altered morphology of dendritic spines and reduction in mEPSC frequency. GluK2 deficiency also resulted in a strong change in the subcellular distribution of KCC2 as well as a smaller somatodendritic gradient in the reversal potential of GABA(A). Strikingly, the aberrant morphology of dendritic spines in GluK2-deficient CA3 pyramidal neurons was restored by overexpression of KCC2. GluK2 silencing in hippocampal neurons significantly reduced the expression of 4.1N and functional form of the actin filament severing protein cofilin. Consistently, assessment of actin dynamics using fluorescence recovery after photobleaching (FRAP) of beta-actin showed a significant increase in the stability of F-actin filaments in dendritic spines. In conclusion, our results demonstrate that GluK2-KCC2 interaction plays an important role in the structural maturation of dendritic spines. This also provides novel insights into the connection between KAR dysfunction, structural plasticity, and developmental disorders.