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Galambos AR, Papp ZT, Boldizsár I, Zádor F, Köles L, Harsing LG, Al-Khrasani M. Glycine Transporter 1 Inhibitors: Predictions on Their Possible Mechanisms in the Development of Opioid Analgesic Tolerance. Biomedicines 2024; 12:421. [PMID: 38398023 PMCID: PMC10886540 DOI: 10.3390/biomedicines12020421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
The development of opioid tolerance in patients on long-term opioid analgesic treatment is an unsolved matter in clinical practice thus far. Dose escalation is required to restore analgesic efficacy, but at the price of side effects. Intensive research is ongoing to elucidate the underlying mechanisms of opioid analgesic tolerance in the hope of maintaining opioid analgesic efficacy. N-Methyl-D-aspartate receptor (NMDAR) antagonists have shown promising effects regarding opioid analgesic tolerance; however, their use is limited by side effects (memory dysfunction). Nevertheless, the GluN2B receptor remains a future target for the discovery of drugs to restore opioid efficacy. Mechanistically, the long-term activation of µ-opioid receptors (MORs) initiates receptor phosphorylation, which triggers β-arrestin-MAPKs and NOS-GC-PKG pathway activation, which ultimately ends with GluN2B receptor overactivation and glutamate release. The presence of glutamate and glycine as co-agonists is a prerequisite for GluN2B receptor activation. The extrasynaptic localization of the GluN2B receptor means it is influenced by the glycine level, which is regulated by astrocytic glycine transporter 1 (GlyT1). Enhanced astrocytic glycine release by reverse transporter mechanisms as a consequence of high glutamate levels or unconventional MOR activation on astrocytes could further activate the GluN2B receptor. GlyT1 inhibitors might inhibit this condition, thereby reducing opioid tolerance.
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Affiliation(s)
- Anna Rita Galambos
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
| | - Zsolt Tamás Papp
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
| | - Imre Boldizsár
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
| | - Ferenc Zádor
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
| | - László Köles
- Department of Oral Biology, Semmelweis University, H-1089 Budapest, Hungary;
| | - Laszlo G. Harsing
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
| | - Mahmoud Al-Khrasani
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvá-rad tér 4, H-1445 Budapest, Hungary; (A.R.G.); (Z.T.P.); (I.B.); (F.Z.)
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Kotlinska JH, Grochecki P, Michalak A, Pankowska A, Kochalska K, Suder P, Ner-Kluza J, Matosiuk D, Marszalek-Grabska M. Neonatal Maternal Separation Induces Sexual Dimorphism in Brain Development: The Influence on Amino Acid Levels and Cognitive Disorders. Biomolecules 2023; 13:1449. [PMID: 37892131 PMCID: PMC10605115 DOI: 10.3390/biom13101449] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/09/2023] [Accepted: 09/23/2023] [Indexed: 10/29/2023] Open
Abstract
Repeated maternal separation (MS) is a useful experimental model in rodents for studying the long-term influence of early-life stress on brain neurophysiology. In our work, we assessed the effect of repeated MS (postnatal day (PND)1-21, 180 min/day) on the postnatal development of rat brain regions involved in memory using proton magnetic resonance spectroscopy (1HMRS) for tissue volume and the level of amino acids such as glutamate, aspartate, glutamine, glycine and gamma-aminobutyric acid (GABA) in the hippocampus. We assessed whether these effects are sex dependent. We also use novel object recognition (NOR) task to examine the effect of MS on memory and the effect of ethanol on it. Finally, we attempted to ameliorate postnatal stress-induced memory deficits by using VU-29, a positive allosteric modulator (PAM) of the metabotropic glutamate type 5 (mGlu5) receptor. In males, we noted deficits in the levels of glutamate, glycine and glutamine and increases in GABA in the hippocampus. In addition, the values of perirhinal cortex, prefrontal cortex and insular cortex and CA3 were decreased in these animals. MS females, in contrast, demonstrated significant increase in glutamate levels and decrease in GABA levels in the hippocampus. Here, the CA1 values alone were increased. VU-29 administration ameliorated these cognitive deficits. Thus, MS stress disturbs amino acids levels mainly in the hippocampus of adult male rats, and enhancement of glutamate neurotransmission reversed recognition memory deficits in these animals.
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Affiliation(s)
- Jolanta H. Kotlinska
- Department of Pharmacology and Pharmacodynamics, Medical University, Chodzki 4A, 20-093 Lublin, Poland;
| | - Pawel Grochecki
- Department of Pharmacology and Pharmacodynamics, Medical University, Chodzki 4A, 20-093 Lublin, Poland;
| | - Agnieszka Michalak
- Independent Laboratory of Behavioral Studies, Medical University, Chodzki 4A, 20-093 Lublin, Poland;
| | - Anna Pankowska
- Department of Radiography, Medical University, Staszica 16, 20-081 Lublin, Poland; (A.P.); (K.K.)
| | - Katarzyna Kochalska
- Department of Radiography, Medical University, Staszica 16, 20-081 Lublin, Poland; (A.P.); (K.K.)
| | - Piotr Suder
- Department of Analytical Chemistry and Biochemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, A. Mickiewicza 30, 30-059 Krakow, Poland; (P.S.); (J.N.-K.)
| | - Joanna Ner-Kluza
- Department of Analytical Chemistry and Biochemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, A. Mickiewicza 30, 30-059 Krakow, Poland; (P.S.); (J.N.-K.)
| | - Dariusz Matosiuk
- Department of Synthesis and Chemical Technology of Pharmaceutical Substances with Computer Modelling Lab, Medical University, Chodzki 4A, 20-093 Lublin, Poland;
| | - Marta Marszalek-Grabska
- Department of Experimental and Clinical Pharmacology, Medical University, Jaczewskiego 8B, 20-090 Lublin, Poland;
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Zaitsu K, Asano T, Kawakami D, Chang J, Hisatsune K, Taniguchi M, Iguchi A. Metabolomics and Data-Driven Bioinformatics Revealed Key Maternal Metabolites Related to Fetal Lethality via Di(2-ethylhexyl)phthalate Exposure in Pregnant Mice. ACS OMEGA 2022; 7:23717-23726. [PMID: 35847272 PMCID: PMC9280929 DOI: 10.1021/acsomega.2c02338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We performed serum metabolome analysis of di(2-ethylhexyl)phthalate (DEHP)-exposed and control pregnant mice. Pregnant mice (n = 5) were fed a DEHP-containing diet (0.1% or 0.2% DEHP) or a normal diet (control) from gestational days 0-18. After maternal exposure to 0.2% DEHP there were no surviving fetuses, indicating its strong fetal lethality. There were no significant differences in the numbers of fetuses and placentas between the 0.1% DEHP and control groups, although fetal viability differed significantly between them, suggesting that maternal exposure to 0.1% DEHP could inhibit fetal growth. Metabolomics successfully detected 169 metabolites in serum. Principal component analysis (PCA) demonstrated that the three groups were clearly separated on PCA score plots. The biological interpretation of PC1 was fetal lethality, whereas PC2 meant metabolic alteration of pregnant mice via DEHP exposure without fetal lethality. In particular, the first component was significantly correlated with fetal viability, demonstrating that maternal metabolome changes via DEHP exposure were strongly related to fetal lethality. Levels of some amino acids were significantly increased in the DEHP-exposed groups, whereas those of some fatty acids, nicotinic acid, and 1,5-anhydroglucitol were significantly decreased in the DEHP groups. DEHP-induced increases in glycine levels could cause fetal neurological disorders, and decreases in nicotinic acid could inhibit fetal growth. In addition, a machine-learning Random forest could determine 16 potential biomarkers of DEHP exposure, and data-driven network analysis revealed that nicotinic acid was the most influential hub metabolite in the metabolic network. These findings will be useful for understanding the effects of DEHP on the maternal metabolome in pregnancy and their relationship to fetal lethality.
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Affiliation(s)
- Kei Zaitsu
- Multimodal
Informatics and Wide-data Analytics Laboratory, Department of Computational
Systems Biology, Faculty of Biology-Oriented Science and Technology, Kindai University, 930 Nishi Mitani, Kinokawa, Wakayama 649-6493, Japan
- In
Vivo Real-time Omics Laboratory, Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Tomomi Asano
- Department
of Human Life and Environment, Kinjo Gakuin
University, 2-1723 Omori, Moriyama-ku, Nagoya 463-8521, Japan
| | - Daisuke Kawakami
- Shimadzu
Corporation, 1, Nishinokyo-Kuwabaracho
Nakagyo-ku, Kyoto, 604-8511, Japan
| | - Jiarui Chang
- In
Vivo Real-time Omics Laboratory, Institute for Advanced Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Kazuaki Hisatsune
- Forensic
Science Laboratory, Aichi Prefectural Police
Headquarters, 2-1-1,
Sannomaru, Naka-ku, Nagoya 460-8502, Japan
| | - Masaru Taniguchi
- Nagoya City
Public Health Research Institute, Shimoshidami, Moriyama-ku, Nagoya 463-8585, Japan
| | - Akira Iguchi
- Marine Geo-Environment
Research Group, Institute of Geology and Geoinformation, National Institute of Advanced Industrial Science
and Technology (AIST), AIST Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8567 Japan
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Seguchi O, Toda K, Hamada Y, Fujita T, Fukushima N. Successful heart transplantation in a patient with adolescent-onset dilated cardiomyopathy secondary to propionic acidaemia: a case report. Eur Heart J Case Rep 2022; 6:ytac202. [PMID: 35685030 PMCID: PMC9174551 DOI: 10.1093/ehjcr/ytac202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/31/2021] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Propionic acidaemia (PA) is an autosomal recessive disorder resulting from deficiency of propionyl-CoA carboxylase, a mitochondrial enzyme that metabolizes propionyl-CoA. Generally, patients with PA develop symptoms in the neonatal period due to protein intake through breastfeeding; however, late-onset PA with atypical symptoms, including cardiomyopathy, has been recently reported. CASE SUMMARY We present the case of a 25-year-old male with late-onset PA complicated by advanced heart failure (HF) due to isolated secondary dilated cardiomyopathy, who required left ventricular assist device (LVAD) implantation and finally underwent heart transplantation (HTx). Initially, the patient developed HF at the age of 16 and was diagnosed with mitochondrial cardiomyopathy. Due to refractory HF, he underwent an LVAD implantation and was scheduled for HTx. During the preoperative period for HTx, the patient suffered from sepsis due to the worsening of LVAD driveline exit-site infection complicated by overt metabolic acidosis, finally leading to the diagnosis of late-onset PA. After this diagnosis, adequate nutritional interventions were introduced, and the cardiac function was partially restored enough for him to be weaned-off LVAD; however, the patient became inotrope dependent and underwent HTx. The post-HTx course was uneventful with special nutritional management, and he has experienced no adverse metabolic events in the past 3 years. DISCUSSION Late-onset PA can cause isolated adult-onset cardiomyopathy, and LVAD or HTx should be considered when PA is complicated by advanced HF and is unresponsive to conventional medical therapies.
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Affiliation(s)
- Osamu Seguchi
- Corresponding authors. Tel: +81 6 6170 1070, Fax: +81 6 6170 1348, E-mails: (O.S.), (N.F.)
| | - Koichi Toda
- Department of Transplant Medicine, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shinmachi Suita-shi, 564-8565 Osaka, Japan
- Department of Pediatrics, Saitama Medical University, International Medical Center, 1397-1 Yamane, Hidaka-City, 350-1298 Saitama, Japan
| | - Yusuke Hamada
- Department of Pediatrics, Toyonaka Municipal Hospital, 4-14-1 Shibahara-cho, Toyonaka-shi, 560-8565 Osaka, Japan
| | - Tomoyuki Fujita
- Department of Cardiac Surgery, National Cerebral and Cardiovascular Center, 6-1 Kishibe-Shinmachi Suita-shi, 564-8565 Osaka, Japan
| | - Norihide Fukushima
- Corresponding authors. Tel: +81 6 6170 1070, Fax: +81 6 6170 1348, E-mails: (O.S.), (N.F.)
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5
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Sanders B, Brula AQ. Intranasal esketamine: From origins to future implications in treatment-resistant depression. J Psychiatr Res 2021; 137:29-35. [PMID: 33647726 DOI: 10.1016/j.jpsychires.2021.02.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/17/2022]
Abstract
The approval of intranasal esketamine for treatment-resistant depression marks the next step in our understanding of and ability to treat treatment-resistant depression. The origin of ketamine is rooted in the search for a phencyclidine analog that could be used as a pre-surgical anesthetic with less emergence delirium. Following its inception, ketamine has been used in a variety of contexts. However, it was the seminal Berman et al., 2000 study, which published positive findings from the first human trial using subanesthetic intravenous ketamine for depression. Since then, a large body of research has investigated ketamine's various proposed antidepressant mechanisms of action, and the role its pharmacokinetic properties and route of administration play in producing its antidepressant effects. The results of this research were the eventual approval of intranasal esketamine for treatment-resistant depression by the U.S. Food and Drug Administration (FDA) in March 2019. By identifying and utilizing predictors of response, we can continue to refine our approach to treating treatment-resistant depression and optimize patient response to intranasal esketamine. In this article, we look at the history, pharmacology, landmark studies, and future implications of intranasal esketamine for treatment-resistant depression.
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Affiliation(s)
- Benjamin Sanders
- University of Kentucky- Bowling Green, 250 Park St. Attn: GME, Bowling Green, KY, 42101, USA.
| | - Abdul Q Brula
- University of Kentucky- Bowling Green, 250 Park St. Attn: GME, Bowling Green, KY, 42101, USA
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6
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Puig-Lagunes ÁA, Rocha L, Morgado-Valle C, BeltrÁn-Parrazal L, LÓpez-Meraz ML. Brain and plasma amino acid concentration in infant rats prenatally exposed to valproic acid. AN ACAD BRAS CIENC 2021; 93:e20190861. [PMID: 33729379 DOI: 10.1590/0001-3765202120190861] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/19/2019] [Indexed: 11/22/2022] Open
Abstract
Autism spectrum disorder is associated with alterations in GABAergic and glutamatergic neurotransmission. Here, we aimed to determine the concentration of GABA, glutamate, glutamine, aspartate, taurine, and glycine in brain tissue and plasma of rats prenatally exposed to valproic acid (VPA), a well-characterized experimental model of autism. Pregnant rats were injected with VPA (600mg/Kg) during the twelfth-embryonic-day. Control rats were injected with saline. On the fourteen-postnatal-day, rats from both groups (males and females) were anesthetized, euthanized by decapitation and their brain dissected out. The frontal cortex, hippocampus, amygdala, brain stem and cerebellum were dissected and homogenized. Homogenates were centrifuged and supernatants were used to quantify amino acid concentrations by HPLC coupled with fluorometric detection. Blood samples were obtained by a cardiac puncture; plasma was separated and deproteinized to quantify amino acid concentration by HPLC. We found that, in VPA rats, glutamate and glutamine concentrations were increased in hippocampus and glycine concentration was increased in cortex. We did not find changes in other regions or in plasma amino acid concentration in the VPA group with respect to control group. Our results suggest that VPA exposure in utero may impair inhibitory and excitatory amino acid transmission in the infant brain.
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Affiliation(s)
- Ángel Alberto Puig-Lagunes
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Médicos y Odontólogos, s/n, Col. Unidad del Bosque, 91010 Xalapa, Veracruz, México
| | - Luisa Rocha
- Departamento de Farmacobiología, Cinvestav, Calzada de los Tenorios, 235, 14330 Col. Granjas Coapa, Ciudad de México, México
| | - Consuelo Morgado-Valle
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Médicos y Odontólogos, s/n, Col. Unidad del Bosque, 91010 Xalapa, Veracruz, México
| | - Luis BeltrÁn-Parrazal
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Médicos y Odontólogos, s/n, Col. Unidad del Bosque, 91010 Xalapa, Veracruz, México
| | - MarÍa-Leonor LÓpez-Meraz
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Médicos y Odontólogos, s/n, Col. Unidad del Bosque, 91010 Xalapa, Veracruz, México
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Gavrilovici C, Rho JM. Metabolic epilepsies amenable to ketogenic therapies: Indications, contraindications, and underlying mechanisms. J Inherit Metab Dis 2021; 44:42-53. [PMID: 32654164 DOI: 10.1002/jimd.12283] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 07/04/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022]
Abstract
Metabolic epilepsies arise in the context of rare inborn errors of metabolism (IEM), notably glucose transporter type 1 deficiency syndrome, succinic semialdehyde dehydrogenase deficiency, pyruvate dehydrogenase complex deficiency, nonketotic hyperglycinemia, and mitochondrial cytopathies. A common feature of these disorders is impaired bioenergetics, which through incompletely defined mechanisms result in a wide spectrum of neurological symptoms, such as epileptic seizures, developmental delay, and movement disorders. The ketogenic diet (KD) has been successfully utilized to treat such conditions to varying degrees. While the mechanisms underlying the clinical efficacy of the KD in IEM remain unclear, it is likely that the proposed heterogeneous targets influenced by the KD work in concert to rectify or ameliorate the downstream negative consequences of genetic mutations affecting key metabolic enzymes and substrates-such as oxidative stress and cell death. These beneficial effects can be broadly grouped into restoration of impaired bioenergetics and synaptic dysfunction, improved redox homeostasis, anti-inflammatory, and epigenetic activity. Hence, it is conceivable that the KD might prove useful in other metabolic disorders that present with epileptic seizures. At the same time, however, there are notable contraindications to KD use, such as fatty acid oxidation disorders. Clearly, more research is needed to better characterize those metabolic epilepsies that would be amenable to ketogenic therapies, both experimentally and clinically. In the end, the expanded knowledge base will be critical to designing metabolism-based treatments that can afford greater clinical efficacy and tolerability compared to current KD approaches, and improved long-term outcomes for patients.
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Affiliation(s)
- Cezar Gavrilovici
- Departments of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, California, USA
| | - Jong M Rho
- Departments of Neurosciences and Pediatrics, University of California San Diego, Rady Children's Hospital, San Diego, California, USA
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8
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Using Serum Amino Acids to Predict Traumatic Brain Injury: A Systematic Approach to Utilize Multiple Biomarkers. Int J Mol Sci 2020; 21:ijms21051786. [PMID: 32150890 PMCID: PMC7084695 DOI: 10.3390/ijms21051786] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/17/2020] [Accepted: 03/02/2020] [Indexed: 01/06/2023] Open
Abstract
Traumatic brain injury (TBI) can cause biochemical and metabolomic alterations in the brain tissue and serum. These alterations can be used for diagnosis and prognosis of TBI. Here, the serum concentrations of seventeen amino acids (AA) were studied for their potential utility as biomarkers of TBI. Twenty-five female, 4-week-old piglets received diffuse (n = 13) or focal (n = 12) TBI. Blood samples were obtained both pre-injury and at either 24-h or 4-days post-TBI. To find a robust panel of biomarkers, the results of focal and diffuse TBIs were combined and multivariate logistic regression analysis, coupled with the best subset selection technique and repeated k-fold cross-validation method, was used to perform a thorough search of all possible subsets of AAs. The combination of serum glycine, taurine, and ornithine was optimal for TBI diagnosis, with 80% sensitivity and 86% overall prediction rate, and showed excellent TBI diagnostic performance, with 100% sensitivity and 78% overall prediction rate, on a separate validation dataset including four uninjured and five injured animals. We found that combinations of biomarkers outperformed any single biomarker. We propose this 3-AA serum biomarker panel to diagnose mild-to-moderate focal/diffuse TBI. The systematic approaches implemented herein can be used for combining parameters from various TBI assessments to develop/evaluate optimal multi-factorial diagnostic/prognostic TBI metrics.
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Chen H, Diao X, Zhou H. Tissue-specific metabolic responses of the pearl oyster Pinctada martensii exposed to benzo[a]pyrene. MARINE POLLUTION BULLETIN 2018; 131:17-21. [PMID: 29886933 DOI: 10.1016/j.marpolbul.2018.03.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/22/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that is well known for its teratogenic, mutagenic and carcinogenic effects. In this study, we applied metabolomics to investigate the tissue-specific metabolic responses of the Pinctada martensii digestive glands and gills after a short-duration exposure to BaP (1 μg/L and 10 μg/L). After 72 h of exposure to BaP, the majority of metabolite changes were related to osmolytes, energy metabolites, and amino acids. BaP (1 μg/L) accelerated energy deterioration and decreased osmotic regulation, while BaP (10 μg/L) disturbed energy metabolism and increased osmotic stress in the digestive glands. Both BaP doses disturbed osmotic regulation and energy metabolism in the gills. BaP also induced neurotoxicity in both tissues. These findings demonstrated that BaP exhibited tissue-specific metabolic responses in P. martensii. The difference in these metabolite responses between the digestive glands and gills might prove to be suitable biomarkers for indicating exposure to specific marine pollutants.
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Affiliation(s)
- Hao Chen
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China
| | - Xiaoping Diao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
| | - Hailong Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China; Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
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10
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Abstract
West syndrome (WS) is an early life epileptic encephalopathy associated with infantile spasms, interictal electroencephalography (EEG) abnormalities including high amplitude, disorganized background with multifocal epileptic spikes (hypsarrhythmia), and often neurodevelopmental impairments. Approximately 64% of the patients have structural, metabolic, genetic, or infectious etiologies and, in the rest, the etiology is unknown. Here we review the contribution of etiologies due to various metabolic disorders in the pathology of WS. These may include metabolic errors in organic molecules involved in amino acid and glucose metabolism, fatty acid oxidation, metal metabolism, pyridoxine deficiency or dependency, or acidurias in organelles such as mitochondria and lysosomes. We discuss the biochemical, clinical, and EEG features of these disorders as well as the evidence of how they may be implicated in the pathogenesis and treatment of WS. The early recognition of these etiologies in some cases may permit early interventions that may improve the course of the disease.
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Affiliation(s)
- Seda Salar
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
| | - Solomon L. Moshé
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Dominick P. Purpura Department of NeuroscienceMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Department of PediatricsMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
| | - Aristea S. Galanopoulou
- Laboratory of Developmental EpilepsySaul R. Korey Department of NeurologyMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
- Dominick P. Purpura Department of NeuroscienceMontefiore/Einstein Epilepsy CenterAlbert Einstein College of MedicineBronxNew YorkU.S.A.
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Vodovozov W, Schneider J, Elzoheiry S, Hollnagel JO, Lewen A, Kann O. Metabolic modulation of neuronal gamma-band oscillations. Pflugers Arch 2018; 470:1377-1389. [DOI: 10.1007/s00424-018-2156-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/06/2018] [Accepted: 05/17/2018] [Indexed: 01/08/2023]
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12
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Weinberg JM, Bienholz A, Venkatachalam MA. The role of glycine in regulated cell death. Cell Mol Life Sci 2016; 73:2285-308. [PMID: 27066896 PMCID: PMC4955867 DOI: 10.1007/s00018-016-2201-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 01/22/2023]
Abstract
The cytoprotective effects of glycine against cell death have been recognized for over 28 years. They are expressed in multiple cell types and injury settings that lead to necrosis, but are still not widely appreciated or considered in the conceptualization of cell death pathways. In this paper, we review the available data on the expression of this phenomenon, its relationship to major pathophysiologic pathways that lead to cell death and immunomodulatory effects, the hypothesis that it involves suppression by glycine of the development of a hydrophilic death channel of molecular dimensions in the plasma membrane, and evidence for its impact on disease processes in vivo.
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Affiliation(s)
- Joel M Weinberg
- Division of Nephrology, Department of Internal Medicine, Veterans Affairs Ann Arbor Healthcare System and University of Michigan, Room 1560, MSRB II, Ann Arbor, MI, 48109-0676, USA.
| | - Anja Bienholz
- Department of Nephrology, University Duisburg-Essen, 45122, Essen, Germany
| | - M A Venkatachalam
- Department of Pathology, University of Texas Health Science Center, San Antonio, TX, 78234, USA
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Chen Z, Hu B, Wang F, Du L, Huang B, Li L, Qi J, Wang X. Glycine bidirectionally regulates ischemic tolerance via different mechanisms including NR2A-dependent CREB phosphorylation. J Neurochem 2015; 133:397-408. [PMID: 25418841 DOI: 10.1111/jnc.12994] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 11/07/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Zheng Chen
- Division of Vascular Surgery, East Hospital; Tongji University School of Medicine; Shanghai China
- Department of Neurosurgery; First Affiliated Hospital of Nanjing Medical University; Nanjing China
- Laboratory of Brain Diseases; College of Basic Medicine; Nanjing University of Chinese Medicine; Nanjing China
| | - Bin Hu
- Jiangsu Key Laboratory of Brain Disease Bioinformation; Research Center for Biochemistry and Molecular Biology; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Fuzhou Wang
- Department of Anesthesiology; Affiliated Nanjing Maternity and Child Health Care Hospital; Nanjing Medical University; Nanjing China
| | - Linlin Du
- Laboratory of Brain Diseases; College of Basic Medicine; Nanjing University of Chinese Medicine; Nanjing China
| | - Baosheng Huang
- Department of Neurosurgery; First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - Lixin Li
- Department of Neurosurgery; First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - Jia Qi
- Department of Pharmacy; Xinhua Hospital Affiliated to Shanghai Jiaotong University; Shanghai China
| | - Xiang Wang
- Division of Vascular Surgery, East Hospital; Tongji University School of Medicine; Shanghai China
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Sawin EA, Murali SG, Ney DM. Differential effects of low-phenylalanine protein sources on brain neurotransmitters and behavior in C57Bl/6-Pah(enu2) mice. Mol Genet Metab 2014; 111:452-61. [PMID: 24560888 PMCID: PMC3995025 DOI: 10.1016/j.ymgme.2014.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 01/30/2014] [Indexed: 11/24/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of metabolism caused by a deficiency of the enzyme phenylalanine hydroxylase, which metabolizes phenylalanine (phe) to tyrosine. A low-phe diet plus amino acid (AA) formula is necessary to prevent cognitive impairment; glycomacropeptide (GMP) contains minimal phe and provides a palatable alternative to the AA formula. Our objective was to assess neurotransmitter concentrations in the brain and the behavioral phenotype of PKU mice (Pah(enu2) on the C57Bl/6 background) and how this is affected by low-phe protein sources. Wild type (WT) and PKU mice, both male and female, were fed high-phe casein, low-phe AA, or low-phe GMP diets between 3 and 18 weeks of age. Behavioral phenotype was assessed using the open field and marble burying tests, and brain neurotransmitter concentrations were measured using HPLC with electrochemical detection system. Data were analyzed by 3-way ANOVA with genotype, sex, and diet as the main treatment effects. Brain mass and the concentrations of catecholamines and serotonin were reduced in PKU mice compared to WT mice; the low-phe AA and GMP diets improved these parameters in PKU mice. Relative brain mass was increased in female PKU mice fed the GMP diet compared to the AA diet. PKU mice exhibited hyperactivity and impaired vertical exploration compared to their WT littermates during the open field test. Regardless of genotype or diet, female mice demonstrated increased vertical activity time and increased total ambulatory and horizontal activity counts compared with male mice. PKU mice fed the high-phe casein diet buried significantly fewer marbles than WT control mice fed casein; this was normalized in PKU mice fed the low-phe AA and GMP diets. In summary, C57Bl/6-Pah(enu2) mice showed an impaired behavioral phenotype and reduced brain neurotransmitter concentrations that were improved by the low-phe AA or GMP diets. These data support lifelong adherence to a low-phe diet for PKU.
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Affiliation(s)
- Emily A Sawin
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Sangita G Murali
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
| | - Denise M Ney
- Department of Nutritional Sciences, University of Wisconsin-Madison, WI 53706, USA.
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15
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Chen RQ, Wang SH, Yao W, Wang JJ, Ji F, Yan JZ, Ren SQ, Chen Z, Liu SY, Lu W. Role of glycine receptors in glycine-induced LTD in hippocampal CA1 pyramidal neurons. Neuropsychopharmacology 2011; 36:1948-58. [PMID: 21593734 PMCID: PMC3154115 DOI: 10.1038/npp.2011.86] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Glycine in the hippocampus can exert its effect on both synaptic NMDA receptors (NMDARs) and extrasynaptic functional glycine receptors (GlyRs) via distinct binding sites. Previous studies have reported that glycine induces long-term potentiation (LTP) through the activation of synaptic NMDARs. However, little is known about the potential role of the activated GlyRs that are largely located in extrasynaptic regions. We report here that relatively high levels of glycine achieved either by exogenous glycine application or by the elevation of endogenous glycine accumulation with an antagonist of the glycine transporter induced long-term depression (LTD) of excitatory postsynaptic currents (EPSCs) in hippocampal CA1 pyramidal neurons. The co-application of glycine with the selective GlyR antagonist strychnine changed glycine-induced LTD (Gly-LTD) to LTP. Blocking the postsynaptic GlyR-gated net chloride flux by manipulating intracellular chloride concentrations failed to elicit any changes in EPSCs. These results suggest that GlyRs are involved in Gly-LTD. Furthermore, this new form of chemical LTD was accompanied by the internalization of postsynaptic AMPA receptors and required the activation of NMDARs. Therefore, our present findings reveal an important function of GlyR activation and modulation in gating the direction of synaptic plasticity.
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Affiliation(s)
- Rong-Qing Chen
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Shan-Hui Wang
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Wen Yao
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Jing-Jing Wang
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Fang Ji
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Jing-Zhi Yan
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Si-Qiang Ren
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Zheng Chen
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Su-Yi Liu
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Wei Lu
- Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Neurodegenerative Disease of Jiangsu Province, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Key Laboratory for Human Functional Genomics of Jiangsu Province, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China,Department of Neurobiology, Nanjing Medical University, Nanjing, Jiangsu 210029, People's Republic of China, Tel: +86 25 86862822, Fax: +86 25 86862822, E-mail:
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16
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Role of prostanoid production and receptors in the regulation of retinal endogenous amino acid neurotransmitters by 8-isoprostaglandin E2, ex vivo. Neurochem Res 2011; 34:2170-80. [PMID: 19513831 DOI: 10.1007/s11064-009-0013-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2009] [Indexed: 12/11/2022]
Abstract
The role of enzymes and receptors of the prostanoid pathway in the inhibitory effect of 8-isoprostaglandin E2 (8-isoPGE2) on endogenous amino acid neurotransmitter levels was examined, ex vivo. Freshly isolated bovine eyeballs were injected intravitreally with IsoPs, incubated in Krebs buffer for 30 min and retina prepared for HPLC-ECD detection of amino acids. 8-isoPGE2 attenuated retinal glutamate and its metabolite, glutamine and glycine in a concentration-dependent manner. The nonselective cyclooxygenase (COX)-inhibitor, flurbiprofen, COX-2 selective inhibitor, NS-398 and thromboxane (Tx) synthase inhibitor, furegrelate had no effect on both basal amino acid levels and the inhibitory effects of 8-isoPGE2 (1-100 μM) on the retinal amino acids. Whereas the TP-receptor antagonist SQ-29548(10 μM) exhibited no effect, SC-19220(EP1; 30 μM), AH-6809(EP(1-3); 30 μM) and AH-23848(EP4; 30 μM) reversed the inhibitory effects of 8-isoPGE2 (0.01-100 μM) on glutamate, glutamine and glycine levels. We conclude that prostanoid EP-receptors regulate the inhibitory effect of 8-isoPGE2 on basal levels of endogenous amino acids in bovine retina, ex vivo.
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17
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Tanabe M, Nitta A, Ono H. Neuroprotection via Strychnine-Sensitive Glycine Receptors During Post-ischemic Recovery of Excitatory Synaptic Transmission in the Hippocampus. J Pharmacol Sci 2010; 113:378-86. [DOI: 10.1254/jphs.10150fp] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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18
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Davidson ME, Kerepesi LA, Soto A, Chan VT. d-Serine exposure resulted in gene expression changes implicated in neurodegenerative disorders and neuronal dysfunction in male Fischer 344 rats. Arch Toxicol 2009; 83:747-62. [DOI: 10.1007/s00204-009-0405-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Accepted: 01/15/2009] [Indexed: 01/09/2023]
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19
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Igartua I, Solís JM, Bustamante J. Glycine-induced long-term synaptic potentiation is mediated by the glycine transporter GLYT1. Neuropharmacology 2007; 52:1586-95. [PMID: 17462677 DOI: 10.1016/j.neuropharm.2007.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 02/13/2007] [Accepted: 03/05/2007] [Indexed: 11/29/2022]
Abstract
The negative symptoms of schizophrenia are reverted by treatment with glycine or other agonists of the glycine-B site which facilitate NMDA receptor function. On the other hand, there are experimental observations showing that exogenous application of glycine (0.5-10mM) results in a long-lasting potentiation of glutamatergic synaptic transmission (LTP-GLY). The characterization of the mechanisms underlying LTP-GLY could be useful to develop new therapies for schizophrenia. The main goal of this work is to deepen the understanding of this potentiation phenomenon. The present study demonstrates in rat hippocampal slices that superfusion of glycine 1mM during 30 min produces a potentiation of excitatory postsynaptic potentials in CA3-CA1 pathway lasting at least 1h. Glycine application does not modify neither presynaptic fiber volley nor paired-pulse facilitation of synaptic potentials. This LTP-GLY is independent of both strychnine-sensitive glycine receptors and nifedipine-sensitive calcium channels. Interestingly, LTP-GLY is not inhibited but strengthened by NMDA receptors antagonists such as AP-5 or MK-801. In contrast, LTP-GLY is partially or totally blocked with the antagonists of glycine transporter GLYT1, sarcosine or ALX-5407, respectively. These results indicate that LTP-GLY requires the activation of GLYT1, a glycine transporter co-localized and associated to NMDA receptors. In addition, the fact that NMDA receptor inhibition increases LTP-GLY magnitude, opens the possibility that these receptors could have a negative control on GLYT1 activity.
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Affiliation(s)
- Itziar Igartua
- Servicio de Neurobiología-Investigación, Hospital Ramón y Cajal, 28034 Madrid, Spain
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20
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Oda M, Kure S, Sugawara T, Yamaguchi S, Kojima K, Shinka T, Sato K, Narisawa A, Aoki Y, Matsubara Y, Omae T, Mizoi K, Kinouchi H. Direct correlation between ischemic injury and extracellular glycine concentration in mice with genetically altered activities of the glycine cleavage multienzyme system. Stroke 2007; 38:2157-64. [PMID: 17510459 DOI: 10.1161/strokeaha.106.477026] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Ischemia elicits the rapid release of various amino acid neurotransmitters. A glutamate surge activates N-methyl-d-aspartate (NMDA) glutamate receptors, triggering deleterious processes in neurons. Although glycine is a coagonist of the NMDA receptor, the effect of extracellular glycine concentration on ischemic injury remains controversial. To approach this issue, we examined ischemic injury in mice with genetically altered activities of the glycine cleavage multienzyme system (GCS), which plays a fundamental role in maintaining extracellular glycine concentration. METHODS A mouse line with increased GCS activity (340% of C57BL/6 control mice) was generated by transgenic expression of glycine decarboxylase, a key GCS component (high-GCS mice). Another mouse line with reduced GCS activity (29% of controls) was established by transgenic expression of a dominant-negative mutant of glycine decarboxylase (low-GCS mice). We examined neuronal injury after transient occlusion of the middle cerebral artery in these mice by measuring extracellular amino acid concentrations in microdialysates. RESULTS High-GCS and low-GCS mice had significantly lower and higher basal concentrations of extracellular glycine than did controls, respectively. In low-GCS mice, the extracellular glycine concentration reached 2-fold of control levels during ischemia, and infarct volume was significantly increased by 69% with respect to controls. In contrast, high-GCS mice had a significantly smaller infarct volume (by 21%). No significant difference was observed in extracellular glutamate concentrations throughout the experiments. An antagonist for the NMDA glycine site, SM-31900, attenuated infarct size, suggesting that glycine operated via the NMDA receptor. CONCLUSIONS There is a direct correlation between ischemic injury and extracellular glycine concentration maintained by the GCS.
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Affiliation(s)
- Masaya Oda
- Department of Medical Genetics, Tohoku University School of Medicine, Seiryomachi, Aobaku, Japan
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21
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Karanian DA, Baude AS, Brown QB, Parsons CG, Bahr BA. 3-Nitropropionic acid toxicity in hippocampus: protection through N-methyl-D-aspartate receptor antagonism. Hippocampus 2006; 16:834-42. [PMID: 16897723 DOI: 10.1002/hipo.20214] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The over-activation of glutamate receptors can lead to excitotoxic cell death and is believed to be involved in the progression of neurodegenerative events in the vulnerable hippocampus. Here, we used an in vitro slice model to study toxicity produced in the hippocampus by the mitochondrial toxin 3-nitropropionic acid (3-NP). The organotypic slice cultures exhibit native cellular organization as well as dense arborization of neuronal processes and synaptic contacts. The hippocampal slices were exposed to 3-NP for 2-20 days, causing calpain-mediated breakdown of the spectrin cytoskeleton, a loss of pre- and postsynaptic markers, and neuronal atrophy. The N-methyl-D-aspartate (NMDA) receptor antagonist memantine reduced both the cytoskeletal damage and synaptic decline in a dose-dependent manner. 3-NP-induced cytotoxicity, as determined by the release of lactate dehydrogenase, was also reduced by memantine with EC50 values from 1.7 to 2.3 microM. Propidium iodide fluorescence and phase contrast microscopy confirmed memantine neuroprotection against the chronic toxin exposure. In addition, the protected tissue exhibited normal neuronal morphology in the major hippocampal subfields. These results indicate that antagonists of NMDA-type glutamate receptors are protective during the toxic outcome associated with mitochondrial dysfunction. They also provide further evidence of memantine's therapeutic potential against neurodegenerative diseases.
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Affiliation(s)
- David A Karanian
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269-3092, USA.
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22
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Barth A, Nguyen LB, Barth L, Newell DW. Glycine-induced neurotoxicity in organotypic hippocampal slice cultures. Exp Brain Res 2004; 161:351-7. [PMID: 15490133 DOI: 10.1007/s00221-004-2079-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2004] [Accepted: 07/27/2004] [Indexed: 10/26/2022]
Abstract
The role of the neutral amino acid glycine in excitotoxic neuronal injury is unclear. Glycine coactivates glutamate N-methyl-D-aspartate (NMDA) receptors by binding to a distinct recognition site on the NR1 subunit. Purely excitatory glycine receptors composed of NR1 and NR3/NR4 NMDA receptor subunits have recently been described, raising the possibility of excitotoxic effects mediated by glycine alone. We have previously shown that exposure to high concentrations of glycine causes extensive neurotoxicity in organotypic hippocampal slice cultures by activation of NMDA receptors. In the present study, we investigated further properties of in vitro glycine-mediated toxicity. Agonists of the glycine recognition site of NMDA receptors (D-serine and D-alanine) did not have any toxic effect in hippocampal cultures, whereas competitive blockade of the glycine site by 7-chlorokynurenic acid was neuroprotective. Stimulation (taurine, beta-alanine) or inhibition (strychnine) of the inhibitory strychnine-sensitive glycine receptors did not produce any neurotoxicity. The toxic effects of high-dose glycine were comparable in extent to those produced by the excitatory amino acid glutamate in our model. When combined with sublethal hypoxia/hypoglycemia, the threshold of glycine toxicity was decreased to less than 1 mM, which corresponds to the range of concentrations of excitatory amino acids measured during in vivo cerebral ischemia. Taken together, these results further support the assumption of an active role of glycine in excitotoxic neuronal injury.
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Affiliation(s)
- A Barth
- Department of Neurological Surgery, University of Washington, School of Medicine, Seattle, WA, USA.
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Peterson SL, Purvis RS, Griffith JW. Differential Neuroprotective Effects of the NMDA Receptor-Associated Glycine Site Partial Agonists 1-Aminocyclopropanecarboxylic Acid (ACPC) and d-Cycloserine in Lithium-Pilocarpine Status Epilepticus. Neurotoxicology 2004; 25:835-47. [PMID: 15288514 DOI: 10.1016/j.neuro.2004.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Accepted: 01/13/2004] [Indexed: 11/30/2022]
Abstract
The status epilepticus (SE) induced in rats by lithium-pilocarpine (Li-pilo) shares many common features with soman-induced SE including a glutamatergic phase that is inhibited by NMDA antagonists. The present study determined whether 1-aminocyclopropanecarboxylic acid (ACPC) or D-cycloserine (DCS), both partial agonists of the strychnine-insensitive glycine site on the NMDA receptor ionophore complex, exerted anticonvulsant or neuroprotectant activity in Li-pilo SE. ACPC or DCS were administered either immediately following pilocarpine (exposure treatment) or 5 min after the onset of SE as determined by ECoG activity. SE was allowed to proceed for 3 h before termination with propofol. The rats were sacrificed 24 h following pilocarpine administration. Neither drug had an effect on the latency to seizure onset or the duration of seizure activity. ACPC administered 5 min after SE onset produced significant neuroprotection in cortical regions, amygdala and CA1 of the hippocampus. In contrast, when administered as exposure treatment ACPC enhanced the neural damage in the thalamus and CA3 of the hippocampus suggesting the neuropathology in those regions is mediated by a different subset of NMDA receptors. DCS had no neuroprotectant activity in Li-pilo SE but exacerbated neuronal damage in the thalamus. Neither drug affected the cholinergic convulsions but both had differential effects on neural damage. This suggests that the SE-induced seizure activity and subsequent neuronal damage involve independent mechanisms.
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Affiliation(s)
- Steven L Peterson
- College of Pharmacy, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA.
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da Costa MDDL, Gonçalves LR, Barbosa ER, Bacheschi LA. [Neuroimaging abnormalities in parkinsonism: study of five cases]. ARQUIVOS DE NEURO-PSIQUIATRIA 2003; 61:381-6. [PMID: 12894271 DOI: 10.1590/s0004-282x2003000300011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
We report the brain magnetic resonance (MR) imaging abnormalities observed at the basal ganglia system of 5 patients (2 female and 3 male), who fulfilled the criteria of parkinsonism. The onset of parkinsonian syndrome ranged from 5 to 52 years old. All patients underwent MR exams with a 1.5T MR equipment. High field T2-weighted sequences disclosed hypersignal bilateral and symmetrically located exclusively at substantia nigra (3 cases), exclusively at globus pallidus (1case) and simultaneously at substantia nigra, globus pallidus and nigro-strital interconnections (1case). For three patients, the diagnose of secondary parkinsonism was supported by clinical data: the first had the onset of the symptoms after the exposure to an herbicide (glyphosate); the second after vaccination against measles; the third after coma due to encephalitis. For the other two patients, the onset of PS was progressive, resembling a typical idiopathic Parkinson's disease (PD) but the findings at the MR dimissed this initial diagnose. In this study, the contribution of neuroimaging was crucial to recognize secondary parkinsonism though the ethiological agents could not be determined in these patients.
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Abstract
The beneficial effects of hypothermia have long been known in non-traditional medicine but it is only in the past few decades that studies on the neuroprotective effects of hypothermia in hypoxic-ischemic brain injury have begun. Different mechanisms have been put forward to explain hypothermic neuroprotection including reduction of the excessive release of the excitatory amino acid neurotransmitter, glutamate. Recent experiments have questioned the key role of this neurotoxin in hypoxic-ischemic neuropathogenesis. In contrast, a mediatory role for another neurotransmitter, glycine in the neuroprotective effects of hypothermia has become more attractive, along with an indication of its role in the pathogenesis of ischemic neuronal damage. Thus, on the basis of reviewing relevant literature the hypothesis of a glycine-related mechanism of hypothermic neuroprotection in ischemia-induced neuronal injury has been put forward.
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Affiliation(s)
- Giuli Kvrivishvili
- Department of Anatomy, School of Veterinary Sciences, Southwell Street, Bristol BS2 8EJ, UK.
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Carpenedo R, Meli E, Peruginelli F, Pellegrini-Giampietro DE, Moroni F. Kynurenine 3-mono-oxygenase inhibitors attenuate post-ischemic neuronal death in organotypic hippocampal slice cultures. J Neurochem 2002; 82:1465-71. [PMID: 12354294 DOI: 10.1046/j.1471-4159.2002.01090.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Kynurenine 3-mono-oxygenase (KMO) inhibitors reduce 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) neosynthesis and facilitate kynurenine metabolism towards kynurenic acid (KYNA) formation. They also reduce tissue damage in models of focal or transient global cerebral ischemia in vivo. We used organotypic hippocampal slice cultures exposed to oxygen and glucose deprivation (OGD) to investigate KMO mechanism(s) of neuroprotective activity. Exposure of the slices to 30 min of OGD caused CA1 pyramidal cell death and significantly decreased the amount of KYNA released in the incubation medium. The KMO inhibitors (m-nitrobenzoyl)-alanine (30-100 micro m) or 3,4-dimethoxy-[-N-4-(nitrophenyl)thiazol-2yl]-benzenesulfonamide (1-10 micro m) reduced post-ischemic neuronal death and increased KYNA concentrations in slice incubation media. The maximal concentration of KYNA detected in the incubation media of slices treated with KMO inhibitors was approximately 50 nm and was too low to efficiently interact with alpha7 nicotinic acetylcholine receptors or with the glycineb site of N-methyl-d-aspartate (NMDA) receptors. On the other hand, the addition of either 3-HK or QUIN (1-10 micro m) to OGD-exposed hippocampal slices prevented the neuroprotective activity of KMO inhibitors. Our results suggest that KMO inhibitors reduce the neuronal death found in the CA1 region of organotypic hippocampal slices exposed to 30 min of OGD by decreasing the local synthesis of 3-HK and QUIN.
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Affiliation(s)
- Raffaella Carpenedo
- Dipartimento di Farmacologia Preclinica e Clinica, Università di Firenze, Firenze, Italy
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27
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Nikbakht MR, Stone TW. Suppression of presynaptic responses to adenosine by activation of NMDA receptors. Eur J Pharmacol 2001; 427:13-25. [PMID: 11553359 DOI: 10.1016/s0014-2999(01)01171-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interactions between adenosine and NMDA receptors has been investigated using the paired-pulse paradigm in hippocampal slices. This technique allows the study of drug effects specifically at presynaptic terminals. The inhibitory effect of adenosine on population spikes, and the decrease of paired-pulse inhibition assessed using either population spikes or population excitatory postsynaptic potentials, were suppressed by performing the experiments in magnesium-free medium, or by superfusion of the slices with N-methyl-D-aspartate (NMDA) at a concentration (4 microM) which did not itself affect potential size. The suppressant effect of NMDA was prevented by 2-amino-5-phosphonopentanoic acid. All these interactions were still seen in the presence of bicuculline methobromide, 30 microM. Neither alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) nor kainate produced a suppression of adenosine responses. The presence of NMDA did not modify the effects of baclofen on population potentials or paired-pulse inhibition. Activating NMDA receptors by the induction of long-term potentiation or by superfusion with glycine also reduced significantly the effects of adenosine on population spikes and paired-pulse interactions. Increasing population potential size by a mechanism which did not involve the activation of NMDA receptors (increasing stimulus strength) did not change sensitivity to adenosine. When adenosine receptor-selective agonists were tested, it was found that NMDA did not modify the inhibitory effect of the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine, but did enhance the excitatory effect of the adenosine A(2A) receptor agonist 2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680). The combined response to NMDA and CGS21680 was prevented by the adenosine A(2A) receptor selective antagonist 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM241385). It is concluded that NMDA receptor activation can suppress neuronal sensitivity to adenosine by acting at presynaptic sites, and that this interaction results from an increase in the excitatory action of adenosine A(2A) receptors, rather than a depression of A(1) receptor function.
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Affiliation(s)
- M R Nikbakht
- Institute of Biomedical and Life Sciences, West Medical Building, University of Glasgow, Glasgow G12 8QQ, UK
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Abstract
BACKGROUND Facilitation of N-methyl-D-aspartate (NMDA) receptor-mediated neurotransmission via administration of glycine site agonists of the NMDA receptor (e.g., glycine, D-serine), and glycine transport inhibitors may represent an innovative pharmacologic strategy in schizophrenia; however, given the potential involvement of NMDA receptors in the neurotoxicity of excitatory amino acids, possible neurotoxic effects of glycinergic compounds need to be explored. Furthermore, studying brain adaptations to chronic administration of glycine site agonists may provide insights into the therapeutic mechanisms of these drugs. METHODS Adult rats were randomized to one of three nutritional regimens (no glycine supplementation, 1 g/kg/day, or 5 g/kg/day glycine supplementation) and to one of three treatment durations (1, 3, or 5 months). Serum glycine and serine levels at sacrifice and brain sections were examined using histologic markers of neurodegeneration (cresyl violet and silver impregnation staining) and immunohistochemical staining of glial fibrillary acidic protein, microtubule-associated protein, and neurofilament 200. To explore additional neural adaptations to high-dose glycine treatment, immunostaining was also performed for class B, N-type Ca(2+) channels. RESULTS Serum glycine levels increased dose dependently during glycine nutrition, whereas serine levels were not changed. In hippocampal dentate gyrus, the percentage of hypertrophied astrocytes transiently increased at 1 month. At 3 and 5 months of glycine treatment, the density of class B, N-type Ca(2+) channels was reduced in parietal cortex and hippocampus. No evidence of neuronal or glial cell excitotoxic damage or degeneration was registered at either of the treatment intervals studied. CONCLUSIONS These findings demonstrate for the first time that in vivo administration of high-dose glycine may induce brain morphological changes without causing neurotoxic effects. A reduction in density of class B, N-type Ca(2+) channels in specific brain regions may represent one general adaptation to long-term, high-dose glycine treatment.
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Affiliation(s)
- S Shoham
- Research Department, Ezrath Nashim-Herzog Memorial Hospital, Jerusalem, Israel
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29
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Barbosa ER, Leiros da Costa MD, Bacheschi LA, Scaff M, Leite CC. Parkinsonism after glycine-derivate exposure. Mov Disord 2001; 16:565-8. [PMID: 11391760 DOI: 10.1002/mds.1105] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This 54-year-old man accidentally sprayed himself with the chemical agent glyphosate, a herbicide derived from the amino acid glycine. He developed disseminated skin lesions 6 hours after the accident. One month later, he developed a symmetrical parkinsonian syndrome. Two years after the initial exposure to glyphosate, magnetic resonance imaging revealed hyperintense signal in the globus pallidus and substantia nigra, bilaterally, on T2-weighted images. Levodopa/benserazide 500/125 mg daily provided satisfactory clinical outcome.
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Affiliation(s)
- E R Barbosa
- Divisão de Clínica Neurológica, Hospital das Clínicas da Faculdade, Medicina da Universidade, São Paulo, São Paulo, Brazil.
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30
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Breder J, Sabelhaus CF, Opitz T, Reymann KG, Schröder UH. Inhibition of different pathways influencing Na(+) homeostasis protects organotypic hippocampal slice cultures from hypoxic/hypoglycemic injury. Neuropharmacology 2000; 39:1779-87. [PMID: 10884559 DOI: 10.1016/s0028-3908(00)00027-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A prominent feature of cerebral ischemia is the excessive intracellular accumulation of both Na(+) and Ca(2+), which results in subsequent cell death. A large number of studies have focused on pathways involved in the increase of the intracellular Ca(2+) concentration [Ca(2+)](i), whereas the elevation of intracellular Na(+) has received less attention. In the present study we investigated the effects of inhibitors of different Na(+) channels and of the Na(+)/Ca(2+) exchanger, which couples the Na(+) to the Ca(2+) gradient, on ischemic damage in organotypic hippocampal slice cultures. The synaptically evoked population spike in the CA1 region was taken as a functional measure of neuronal integrity. Neuronal cell death was assessed by propidium iodide staining. The Na(+) channel blocker tetrodotoxin, and the NMDA receptor blocker MK 801, but not the AMPA/kainate receptor blocker NBQX prevented ischemic cell death. The novel Na(+)/Ca(2+) exchange inhibitor 2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea methanesulfonate (KB-R7943), which preferentially acts on the reverse mode of the exchanger, leading to Ca(2+) accumulation, also reduced neuronal damage. At higher concentrations, KB-R7943 also inhibits Ca(2+) extrusion by the forward mode of the exchanger and exaggerates neuronal cell death. Neuroprotection by KB-R7943 may be due to reducing the [Ca(2+)](i) increase caused by the exchanger.
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Affiliation(s)
- J Breder
- Project Group Neuropharmacology, Leibniz Institute for Neurobiology, POB 1860, D-39008, Magdeburg, Germany.
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31
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Byrd KE, Yang L, Yancey KW, Teomim D, Domb AJ. Increased in vivo levels of neurotransmitters to trigeminal motoneurons: effects on craniofacial bone and TMJ. THE ANATOMICAL RECORD 2000; 258:369-83. [PMID: 10737855 DOI: 10.1002/(sici)1097-0185(20000401)258:4<369::aid-ar5>3.0.co;2-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The results of chronic, in vivo delivery of excitatory and inhibitory neurotransmitter substances upon the craniofacial skeleton are of ongoing interest to clinician and basic scientist alike. Our purpose was to document and compare the effects of biodegradable glycine, glutamate, and thyrotropin-releasing hormone (TRH) microspheres upon the craniofacial skeleton and TMJ of actively growing rats. Glycine, glutamate, TRH, and blank microspheres were stereotactically implanted in proximity to motoneurons within the trigeminal motor nucleus in order to test the following null hypotheses: (1) neurotransmitter microspheres implanted near trigeminal motoneurons of growing rats have no significant effect on the craniofacial skeleton and temporomandibular joints of implanted animals, and (2) there are no significant differences between the relative effects of glutamate, TRH (excitatory to trigeminal motoneurons), and glycine (inhibitory to trigeminal motoneurons) implants upon the craniofacial skeleton and temporomandibular joint. Fifty male Sprague-Dawley rats underwent stereotactic neurosurgery at 35 days; five rats each were killed at 14 and 21 days postoperative for data collection and comparison between glycine-, glutamate-, TRH-, blank-microsphere, and sham-surgery rats. Glycine rats had significantly (P < or = 0.05, 0. 01) smaller implant-side cranial dimensions and mandibular condyles, all glycine rats showed increased gracility of implant-side bones, and deviation of their facial skeleton away from the implant-side; this was in contrast to the generally larger implant-side bony structures in both glutamate and TRH rats. The two null hypotheses were both rejected. Due to their inhibitory and excitatory effects upon trigeminal motoneurons, masticatory muscles, and their neuromuscular generation of biomechanical forces that affect bone, the neurotransmitter substances glycine, glutamate, and TRH appear to play an important role in the growth and development of the mammalian craniofacial skeleton and TMJ.
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Affiliation(s)
- K E Byrd
- Department of Anatomy, Indiana University School of Medicine, Indianapolis 46202, USA.
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32
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Abstract
There is evidence of high glycine concentrations in the brains and periphery of schizophrenics. In the forebrain, glycine plays a major role as a co-agonist with glutamate at the excitatory N-methyl-D-aspartate (NMDA) receptors. This activity of glycine is involved in the normal functioning of the brain in adulthood and during neurodevelopment, and it may also cause neurotoxicity and brain abnormalities when its concentrations are high. To test the hypothesis that the high glycine concentrations observed in schizophrenics play an etiologic role in schizophrenia, an animal model was tested where rats were made hyperglycinic from life in utero to adulthood. The hyperglycinic rats showed abnormalities in sensory gating mechanisms, enlarged cerebral ventricles and diminished hippocampal dimensions. All of these abnormalities closely parallel observations reported in patients with schizophrenic psychoses. These results from a rat model suggest an etiologic role for high glycine concentration in the behavior and brain abnormalities of schizophrenic patients.
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Affiliation(s)
- R Waziri
- Psychiatry Research-MEB, University of Iowa College of Medicine, Iowa City 52242-1000, USA.
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Platt B, Bate JR, von Linstow Roloff E, Withington DJ. Glycine induces a novel form of long-term potentiation in the superficial layers of the superior colliculus. Br J Pharmacol 1998; 125:293-300. [PMID: 9786501 PMCID: PMC1565619 DOI: 10.1038/sj.bjp.0702062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The mammalian superior colliculus (SC) is a midbrain nucleus containing space maps of different sensory modalities which show various forms of age- and activity-dependent plasticity in vivo and in vitro. In the present study, we aimed to characterize the role of glycine (Gly) receptors in the SC, and we observed that application of glycine (Gly; 500 microM and 3 mM) for 7 min to SC slices of adult guinea-pigs caused a novel form of long-term potentiation (termed LTPgly) of evoked excitatory postsynaptic potentials recorded in the superficial layers. 2. The strength of potentiation was found to be concentration-dependent and partially independent from synaptic stimulation. 3. LTPgly did not involve NMDA receptor activation as proven by the lack of inhibition by 100 microM D,L-2-amino-5-phosphonovaleric acid (APV) and 10 microM MK-801. 4. LTPgly could only be masked but not prevented by strychnine (100 microM) and remained undisturbed in the presence of picrotoxin (100 microM). 5. Inhibition of carbonic anhydrase by acetazolamide (20 microM) had no effect on LTPgly suggesting that the excitatory action of Gly is not due to a differential breakdown of the Cl-/HCO3 gradients. 6. As indicated by the inhibition of LTPgly of the fEPSP slope by the L-type calcium channel blocker nifedipine (20 microM), voltage-dependent calcium channels are the source for Ca2+ elevation as the intracellular trigger. 7. Our data provide the first evidence for a role of Gly in SC synaptic transmission. They illustrate a so far unknown action of Gly which can lead to long-lasting changes of synaptic efficacy and which is not mediated via NMDA-related or strychnine-sensitive binding sites.
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Affiliation(s)
- B Platt
- Department of Biomedical Sciences, Aberdeen University, Foresterhill, Scotland
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Noraberg J, Gramsbergen JB, Fonnum F, Zimmer J. Trimethyltin (TMT) neurotoxicity in organotypic rat hippocampal slice cultures. Brain Res 1998; 783:305-15. [PMID: 9507172 DOI: 10.1016/s0006-8993(97)01358-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The neurotoxic effects of trimethyltin (TMT) on the hippocampus have been extensively studied in vivo. In this study, we examined whether the toxicity of TMT to hippocampal neurons could be reproduced in organotypic brain slice cultures in order to test the potential of this model for neurotoxicological studies, including further studies of neurotoxic mechanisms of TMT. Four-week-old cultures, derived from 7-day-old donor rats and grown in serum-free medium, were exposed to TMT (0.5-100 microM) for 24 h followed by 24 h in normal medium. TMT-induced neurodegeneration was then monitored by (a) propidium iodide (PI) uptake, (b) lactate dehydrogenase (LDH) efflux into the culture medium, (c) cellular cobalt uptake as an index of calcium influx, (d) ordinary Nissl cell staining, and (e) immunohistochemical staining for microtubule-associated protein 2 (MAP-2). Cellular degeneration as assessed by densitometric measurements of PI uptake displayed a dose and time-dependent increase, with the following ranking of vulnerability of the hippocampal subfields: FD>CA4>/=CA3c>CA1>CA3ab. This differential neuronal vulnerability observed by PI uptake was confirmed by MAP-2 immunostaining and corresponded to in vivo cell stain observations of rats acutely exposed to TMT. The mean PI uptake of the cultures and the LDH efflux into the medium were highly correlated. The combined results obtained by the different markers indicate that the hippocampal slice culture method is a feasible model for further studies of TMT neurotoxicity.
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Affiliation(s)
- J Noraberg
- Dept. of Anatomy and Cell Biology, Inst. of Medical Biology, University of Odense, Odense C DK-5000, Denmark.
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