1
|
Ibusuki Y, Kimata S, Hayakawa Y. 13-Deoxo-13-iminodutomycin, a new neuroprotective compound from Streptomyces sp. RAP78. J Antibiot (Tokyo) 2022; 75:40-43. [PMID: 34824375 DOI: 10.1038/s41429-021-00488-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 09/18/2021] [Accepted: 10/03/2021] [Indexed: 11/09/2022]
Abstract
A neuroprotective compound (2) was isolated from the culture broth of the dutomycin (1) producer Streptomyces sp. RAP78. The molecular formula of 2 was established as C44H55NO16 by high-resolution FAB-MS. The structure was determined to be a new dutomycin derivative possessing an acetimidoyl group in place of an acetyl group by NMR spectroscopic analysis. 13-Deoxo-13-iminodutomycin (2) but not dutomycin (1) protected C6 rat glioma cells and N18-RE-105 rat primary retina-mouse neuroblastoma hybrid cells from glutamate-induced toxicity with EC50s of 0.12 µM and 0.72 µM, respectively.
Collapse
Affiliation(s)
- Yuta Ibusuki
- Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Shoko Kimata
- Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Yoichi Hayakawa
- Department of Medicinal and Life Science, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
| |
Collapse
|
2
|
Dey B, Majumdar S, Dhibar S. Reversible inverse cooling phenomena by trinity of triethylamine, L-glutamic acid and water. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
3
|
Pyroxazone, a new neuroprotective compound from Streptomyces sp. RAN54. J Antibiot (Tokyo) 2018; 71:962-964. [PMID: 30111798 DOI: 10.1038/s41429-018-0085-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Revised: 07/07/2018] [Accepted: 07/23/2018] [Indexed: 11/09/2022]
Abstract
A neuroprotective compound designated pyroxazone (1) was isolated from the culture broth of Streptomyces sp. RAN54. The molecular formula of 1 was established as C18H14N2O5 by high-resolution FAB-MS. The structure was determined to be a new 2-amino-3H-phenoxazin-3-one derivative by NMR spectroscopic analysis. Pyroxazone (1) protected C6 rat glioma cells and N18-RE-105 rat primary retina-mouse neuroblastoma hybrid cells from glutamate-induced toxicity with EC50s of 8.2 µM and 1.7 µM, respectively.
Collapse
|
4
|
van der Valk JB, Vijverberg HP. Neuroblastoma cells as possible model in the study of glutamate receptors. Amino Acids 2013; 1:91-5. [PMID: 24194051 DOI: 10.1007/bf00808095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The sensitivity of several cultured neuroblastoma cell lines toL-glutamate (Glu) and its analogues has been studied with the whole-cell patch clamp technique. Only in the neuroblastoma cell line N2A Glu induced a concentration dependent response consisting of an inward current. In addition, N2A cells responded to superfusion with kainate, quisqualate orN-methyl-D-aspartate, but to a lesser degree than to Glu. It is concluded that N2A cells could be useful as anin vitro model to study excitatory amino acid properties.
Collapse
Affiliation(s)
- J B van der Valk
- Research Institute of Toxicology, University of Utrecht, P.O. Box 80.176, NL-3508, Utrecht, TD, The Netherlands
| | | |
Collapse
|
5
|
Indanostatin, a new neuroprotective compound from Streptomyces sp. J Antibiot (Tokyo) 2013; 66:731-3. [DOI: 10.1038/ja.2013.80] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/06/2013] [Accepted: 07/12/2013] [Indexed: 11/09/2022]
|
6
|
Messmer K, Shen WB, Remington M, Fishman PS. Induction of neural differentiation by the transcription factor neuroD2. Int J Dev Neurosci 2011; 30:105-12. [PMID: 22197973 DOI: 10.1016/j.ijdevneu.2011.12.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 09/30/2011] [Accepted: 12/09/2011] [Indexed: 01/08/2023] Open
Abstract
Pro-neural basic helix loop helix (bHLH) transcription factors are involved in many aspects of normal neuronal development, and over-expression of genes for several of these factors has been shown to induce aspects of neuronal differentiation in cell lines and stem cells. Here we show that over-expression of NeuroD2 (ND2), Neurogenin1 and 2 leads to morphological differentiation of N18-RE-105 neuroblastoma cells and increased expression of synaptic proteins. Particularly ND2 induced neurite formation and increases in the expression of synaptic proteins such as synaptotagmin, that is not expressed normally in this cell type, as well as the redistribution of another synaptic protein, SNAP25, to a cell membrane location. Infection of human neural progenitor cells using adeno associated viral (AAV) vectors also promoted neuronal differentiation. Over-expressing cells demonstrated a significant increase in the neuron specific form of tubulin as well as increased expression of synaptotagmin. Genetic modification of neural progenitor cell with bHLH factors such as ND2 may be a viable strategy to enhance differentiation of these cells into replacement neurons for human disease.
Collapse
Affiliation(s)
- Kirsten Messmer
- Department of Pharmacology and Experimental Therapeutics, University of Maryland, School of Medicine, Baltimore, MD 21201, USA
| | | | | | | |
Collapse
|
7
|
Hayakawa Y, Yamazaki Y, Kurita M, Kawasaki T, Takagi M, Shin-ya K. Flaviogeranin, a new neuroprotective compound from Streptomyces sp. J Antibiot (Tokyo) 2010; 63:379-80. [DOI: 10.1038/ja.2010.49] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
8
|
Townsend SA, Evrony GD, Gu FX, Schulze MP, Brown RH, Langer RS. Tetanus toxin C fragment-conjugated nanoparticles for targeted drug delivery to neurons. Biomaterials 2007; 28:5176-84. [PMID: 17854886 PMCID: PMC2435502 DOI: 10.1016/j.biomaterials.2007.08.011] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 08/02/2007] [Indexed: 02/02/2023]
Abstract
The use of nanoparticles for targeted drug delivery is often facilitated by specific conjugation of functional targeting molecules to the nanoparticle surface. We compared different biotin-binding proteins (avidin, streptavidin, or neutravidin) as crosslinkers to conjugate proteins to biodegradable nanoparticles prepared from poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-biotin polymers. Avidin gave the highest levels of overall protein conjugation, whereas neutravidin minimized protein non-specific binding to the polymer. The tetanus toxin C fragment (TTC), which is efficiently retrogradely transported in neurons and binds to neurons with high specificity and affinity, retained the ability to bind to neuroblastoma cells following amine group modifications. TTC was conjugated to nanoparticles using neutravidin, and the resulting nanoparticles were shown to selectively target neuroblastoma cells in vitro. TTC-conjugated nanoparticles have the potential to serve as drug delivery vehicles targeted to the central nervous system.
Collapse
Affiliation(s)
- Seth A. Townsend
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Gilad D. Evrony
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Frank X. Gu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Martin P. Schulze
- Institute for Pharmacy and Molecular Biotechnology, University of Heidelberg, Im Neuenheimer Feld 580, Heidelberg, 69120, Germany
| | - Robert H. Brown
- Day Neuromuscular Research Laboratory, Massachusetts General Hospital East, 16 Street, Charlestown, MA, 02129, USA
| | - Robert S. Langer
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Address to whom correspondence should be addressed: email , fax (617)258-8827
| |
Collapse
|
9
|
Ono K, Satoh M, Yoshida T, Ozawa Y, Kohara A, Takeuchi M, Mizusawa H, Sawada H. Species identification of animal cells by nested PCR targeted to mitochondrial DNA. In Vitro Cell Dev Biol Anim 2007; 43:168-75. [PMID: 17516125 DOI: 10.1007/s11626-007-9033-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Accepted: 04/17/2007] [Indexed: 11/24/2022]
Abstract
We developed a highly sensitive and convenient method of nested polymerase chain reaction (PCR) targeted to mitochondrial deoxyribonucleic acid (DNA) to identify animal species quickly in cultured cells. Fourteen vertebrate species, including human, cynomolgus monkey, African green monkey, mouse, rat, Syrian hamster, Chinese hamster, guinea pig, rabbit, dog, cat, cow, pig, and chicken, could be distinguished from each other by nested PCR. The first PCR amplifies mitochondrial DNA fragments with a universal primer pair complementary to the conserved regions of 14 species, and the second PCR amplifies the DNA fragments with species-specific primer pairs from the first products. The species-specific primer pairs were designed to easily distinguish 14 species from each other under standard agarose gel electrophoresis. We further developed the multiplex PCR using a mixture of seven species-specific primer pairs for two groups of animals. One was comprised of human, mouse, rat, cat, pig, cow, and rabbit, and the other was comprised of African green monkey, cynomolgus monkey, Syrian hamster, Chinese hamster, guinea pig, dog, and chicken. The sensitivity of the PCR assay was at least 100 pg DNA/reaction, which was sufficient for the detection of each species of DNA. Furthermore, the nested PCR method was able to identify the species in the interspecies mixture of DNA. Thus, the method developed in this study will provide a useful tool for the authentication of animal species.
Collapse
Affiliation(s)
- Kazumi Ono
- Health Science Research Resources Bank (HSRRB), Japan Health Sciences Foundation, 2-11 Rinku-minamihama, Sennan-shi, Osaka 590-0535, Japan
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Shindo K, Kikuta K, Suzuki A, Katsuta A, Kasai H, Yasumoto-Hirose M, Matsuo Y, Misawa N, Takaichi S. Rare carotenoids, (3R)-saproxanthin and (3R,2′S)-myxol, isolated from novel marine bacteria (Flavobacteriaceae) and their antioxidative activities. Appl Microbiol Biotechnol 2007; 74:1350-7. [PMID: 17216447 DOI: 10.1007/s00253-006-0774-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 11/17/2006] [Accepted: 11/17/2006] [Indexed: 11/27/2022]
Abstract
We isolated three orange or yellow pigment-producing marine bacteria, strains 04OKA-13-27 (MBIC08261), 04OKA-17-12 (MBIC08260), and YM6-073 (MBIC06409), off the coast of Okinawa Prefecture in Japan. These strains were classified as novel species of the family Flavobacteriaceae based on their 16S rRNA gene sequence. They were cultured, and the major carotenoids produced were purified by chromatographic methods. Their structures were determined by spectral data to be (3R)-saproxanthin (strain 04OKA-13-27), (3R,2'S)-myxol (strain YM6-073), and (3R,3'R)-zeaxanthin (strains YM6-073 and 04OKA-17-12). Saproxanthin and myxol, which are monocyclic carotenoids rarely found in nature, demonstrated significant antioxidative activities against lipid peroxidation in the rat brain homogenate model and a neuro-protective effect from L-glutamate toxicity.
Collapse
Affiliation(s)
- Kazutoshi Shindo
- Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Tokyo 112-8681, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
D'Orlando C, Celio MR, Schwaller B. Calretinin and calbindin D-28k, but not parvalbumin protect against glutamate-induced delayed excitotoxicity in transfected N18-RE 105 neuroblastoma-retina hybrid cells. Brain Res 2002; 945:181-90. [PMID: 12126880 DOI: 10.1016/s0006-8993(02)02753-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Excitotoxic effects leading to neuronal cell degeneration are often accompanied by a prolonged increase in the intracellular level of Ca(2+) ions and L-glutamate-induced toxicity is assumed to be mediated via a Ca(2+)-dependent mechanism. Due to their buffering properties, EF-hand Ca(2+)-binding proteins (CaBPs) can affect intracellular Ca(2+) homeostasis and a neuroprotective role has been attributed to some of the family members including calretinin, calbindin D-28k and parvalbumin. We have stably transfected N18-RE 105 neuroblastoma-retina hybrid cells with the cDNAs for the three CaBPs and investigated the effect of these proteins on the L-glutamate-induced, Ca(2+)-dependent cytotoxicity. Several clones for each CaBP were selected according to immunocytochemical staining and characterization of the overexpressed proteins by Western blot analysis. In calretinin- and parvalbumin-expressing clones, expression levels were quantitatively determined by ELISA techniques. Cytotoxicity of transfected clones was quantified by measurement of the activity of lactate dehydrogenase (LDH) that was released into the medium after L-glutamate (10 mM) exposure as a result of necrotic cell death. In untransfected and parvalbumin-transfected cells, LDH released into the medium progressively increased (starting from the 20th hour) reaching maximum levels after 28-30 h of glutamate application. In contrast, LDH release in both, calretinin and calbindin D-28k-transfected clones, was not significantly different from unstimulated transfected or untransfected cells over the same period of time. The results indicate that the 'fast' Ca(2+)-buffers calretinin and calbindin D-28k, but not the 'slow' buffer parvalbumin can protect N18-RE 105 cells from this type of Ca(2+)-dependent L-glutamate-induced delayed cytotoxicity.
Collapse
Affiliation(s)
- C D'Orlando
- Institute of Histology and General Embryology, University of Fribourg, CH-1705 Fribourg, Switzerland
| | | | | |
Collapse
|
12
|
Francis JW, Brown RH, Figueiredo D, Remington MP, Castillo O, Schwarzschild MA, Fishman PS, Murphy JR, vanderSpek JC. Enhancement of diphtheria toxin potency by replacement of the receptor binding domain with tetanus toxin C-fragment: a potential vector for delivering heterologous proteins to neurons. J Neurochem 2000; 74:2528-36. [PMID: 10820215 DOI: 10.1046/j.1471-4159.2000.0742528.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study describes the expression, purification, and characterization of a recombinant fusion toxin, DAB(389)TTC, composed of the catalytic and membrane translocation domains of diphtheria toxin (DAB(389)) linked to the receptor binding fragment of tetanus toxin (C-fragment). As determined by its ability to inhibit cellular protein synthesis in primary neuron cultures, DAB(389)TTC was approximately 1,000-fold more cytotoxic than native diphtheria toxin or the previously described fusion toxin, DAB(389)MSH. The cytotoxic effect of DAB(389)TTC on cultured cells was specific toward neuronal-type cells and was blocked by coincubation of the chimeric toxin with tetanus antitoxin. The toxicity of DAB(389)TTC, like that of diphtheria toxin, was dependent on passage through an acidic compartment and ADP-ribosyltransferase activity of the DAB(389) catalytic fragment. These results suggest that a catalytically inactive form of DAB(389)TTC may be useful as a nonviral vehicle to deliver exogenous proteins to the cytosolic compartment of neurons.
Collapse
Affiliation(s)
- J W Francis
- Cecil B. Day Center for Neuromuscular Research, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Shin-Ya K, Kim JS, Furihata K, Hayakawa Y, Seto H. A novel neuronal cell protecting substance mescengricin produced by Streptomyces griseoflavus. JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH 2000; 2:121-132. [PMID: 11252677 DOI: 10.1080/10286020008039901] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Neuronal cell death in brain ischemia reperfusion injury such as stroke was induced by L-glutamate toxicity (Choi, D.W. J. Neurosci. 1990. 10, 2493 2501; Coyle, J.T. and Puttfarcken, P. Science 1993, 262, 689 695). In the course of our screening for neuronal cell protecting substances of microbial origin, we isolated a novel compound designated mescengricin from Streptomyces griseoflavus 2853-SVS4(Kim, J.-S., Shin-ya, K., Furihata, K., Hayakawa, Y. and Seto, H. Tetrahedron Lett. 1997. 38, 3431 3434). The structure of mescengricin was determined by a variety of NMR experiments such as HMBC, D-HMBC (Furihata, K., Seto, H. Tetrahedron Lett. 1995. 36, 2817 2820), 1H 15N HMBC (15N-HMBC). It possesses an alpha-carboline structure substituted by a glycerol-ester and a hydroxydihydropyrone. Mescengricin protected chick primary mesencephalic neurons from L-glutamate toxicity with EC50 value 6.0 nM.
Collapse
Affiliation(s)
- K Shin-Ya
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan
| | | | | | | | | |
Collapse
|
14
|
Kim JS, Shin-ya K, Furihata K, Hayakawa Y, Seto H. Structure of mescengricin, a novel neuronal cell protecting substance produced by Streptomyces griseoflavus. Tetrahedron Lett 1997. [DOI: 10.1016/s0040-4039(97)00638-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
15
|
Kim WG, Kim JP, Koshino H, Shin-Ya K, Seto H, Yoo ID. Benzastatins E, F, and G: New indoline alkaloids with neuronal cell protecting activity from Streptomyces nitrosporeus. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)00157-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
16
|
North WG, Fay MJ, Du J, Cleary M, Gallagher JD, McCann FV. Presence of functional NMDA receptors in a human neuroblastoma cell line. MOLECULAR AND CHEMICAL NEUROPATHOLOGY 1997; 30:77-94. [PMID: 9138430 DOI: 10.1007/bf02815151] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Data are presented that provide convincing evidence for the expression of structurally normal and functional NMDA receptors by acetylcholine-producing human LA-N-2 neuroblastoma cells in culture. Reverse transcription and polymerase chain reaction (RT-PCR), followed by cloning and DNA sequencing, revealed the presence in these cells of mRNA representing the key subunit, NMDAR1, of the receptor. This mRNA was further demonstrated by Northern analysis to be the same size as that described for human neurons. The neutral red cytotoxicity assay was utilized to examine the influence on these neuroblastoma cells of a 48-h incubation with either L-glutamic acid or the specific NMDA agonist N-phthalamoyl-L-glutamic acid (NPG). Cell cytotoxicity was shown by this assay to be increased through incubation with glutamate at 1 and 10 mM by 27 and 37%, and through incubation with NPG at 0.1 and 1 mM by 28 and 46%. A possible mechanism of these toxic effects was further evaluated using the whole-cell configuration of the patch-clamp technique and the specific NMDA agonists (+/-)1-aminocyclobutane-cis-1,3-dicarboxylic acid (ACDA) and NPG. Using this procedure, a voltage-dependent tetrodotoxin-sensitive inward sodium current was found to be increased (x 1.5) by L-glutamic acid and by both NMDA agonists in the presence of glycine. Another voltage-gated inward current, probably carried by calcium ions, was increased three- to fourfold. Hence, these glutamate activities observed in human LA-N-2 neuroblastoma cells appear to occur through the activation of functional NMDA receptors in much the same way as reported for neurons, and both glutamate and NMDA agonists can be toxic to these neuroblastoma cells. Our findings, therefore, suggest this cell line will provide a model suitable for investigating the mechanisms of NMDA-related long-term potentiation (LTP) in neurons and of the NMDA-related neurotoxic effects of glutamate in disease states that involve a reduction in cholinergic function.
Collapse
Affiliation(s)
- W G North
- Department of Physiology, Dartmouth Medical School, Lebanon, NH 03756, USA
| | | | | | | | | | | |
Collapse
|
17
|
Decker DE, Vroegop SM, Buxser SE. Inhibition of oxidative insult in cultured cells by a novel 6-chromanol-containing antioxidant. Biochem Pharmacol 1995; 50:1063-70. [PMID: 7575662 DOI: 10.1016/0006-2952(95)00241-q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
N18-RE-105 neuronal hybridoma cells were used in a cell culture system to evaluate the protective effects of a novel 6-chromanol-containing antioxidant, U78517F. First, the incorporation of the compound into the cells was evaluated, using a serum albumin carrier. Then the cells were exposed to peroxide-generating compounds, and the cell injury was estimated from the loss of alpha-aminoisobutyric acid (AIB) transport. We found that U78517F only protected the cells significantly when the degree of oxidative insult was below a certain limit; the measurable protection of cells by U78517F against either cumene hydroperoxide or H2O2 was limited to a narrow range of concentrations of the reactive oxygen species generator. Additionally, the protection provided by U78517F was largely localized to the cell membrane and did not extend to protection of mitochondrial function. The action of U78517 was fully consistent with a direct radical scavenging in the cells. The results indicate that the following factors must be taken into account for evaluation of antioxidants in cell culture: (a) the delivery of a compound to cells, especially when the compound is lipophilic; (b) the nature and extent of the oxidative insult used to evaluate protection; and (c) the location of the protective agent in the cells.
Collapse
Affiliation(s)
- D E Decker
- Upjohn Company, Upjohn Laboratories, Kalamazoo, MI 49001, USA
| | | | | |
Collapse
|
18
|
Francis JW, Hosler BA, Brown RH, Fishman PS. CuZn superoxide dismutase (SOD-1):tetanus toxin fragment C hybrid protein for targeted delivery of SOD-1 to neuronal cells. J Biol Chem 1995; 270:15434-42. [PMID: 7797532 DOI: 10.1074/jbc.270.25.15434] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Increased levels of CuZn superoxide dismutase (SOD-1) are cytoprotective in experimental models of neurological disorders associated with free radical toxicity (e.g. stroke, trauma). Targeted delivery of SOD-1 to central nervous system neurons may therefore be therapeutic in such diseases. The nontoxic C-fragment of tetanus toxin (TTC) possesses the nerve cell binding/transport properties of tetanus holotoxin and has been used as a vector to enhance the neuronal uptake of proteins including enzymes. We have now produced a recombinant, hybrid protein in Escherichia coli tandemly joining human SOD-1 to TTC. The expressed hybrid protein (SOD:Tet450) has a subunit molecular mass of 68 kDa and is recognized by both anti-SOD-1 and anti-TTC antibodies. Calculated per mol, SOD:Tet450 has approximately 60% of the expected SOD-1 enzymatic activity. Analysis of the hybrid protein's interaction with the neuron-like cell line, N18-RE-105, and cultured hippocampal neurons by enzyme immunoassay for human SOD-1 revealed that SOD:Tet451 association with cells was neuron-specific and dose-dependent. The hybrid protein was also internalized, but there was substantial loss of internalized hybrid protein over the first 24 h. Hybrid protein associated with cells remained enzymatically active. These results suggest that human SOD-1 and TTC retain their respective functional properties when expressed together as a single peptide. SOD:Tet451 may prove to be a useful agent for the targeted delivery of SOD-1 to neurons.
Collapse
Affiliation(s)
- J W Francis
- Department of Anatomy, University of Maryland School of Medicine, Baltimore 21201, USA
| | | | | | | |
Collapse
|
19
|
Decker DE, Vroegop SM, Goodman TG, Peterson T, Buxser SE. Kinetics and thermodynamics of emulsion delivery of lipophilic antioxidants to cells in culture. Chem Phys Lipids 1995; 76:7-25. [PMID: 7788801 DOI: 10.1016/0009-3084(94)02429-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Oil-in-water emulsions are being used increasingly for the delivery of lipophilic drugs, but the fundamental physicochemical principles governing such delivery have not been explored. We determined the kinetics and thermodynamics of delivery from emulsions to cells in culture for two lipophilic compounds, U74006 and U74500. Two fundamental properties dominate the delivery, (a) the concentration of the compound in the lipid phase of the emulsion is directly proportional to the concentration of the compound in cells at equilibrium, and (b) the rate of transfer is directly proportional to the concentration of particles in contact with the cells. Thus, the transfer is consistent with direct partitioning from the lipid phase of the emulsion to cells and occurs by the direct collision of emulsion particles with cells. The details of the mechanism of delivery differ between the two compounds. Specifically, delivery of U74006 is first-order with respect to the drug accumulating in the cells. The transfer of U74500 is best described as a sum of two simultaneous pseudo first-order processes consistent with delivery from a single donor compartment to two receiver compartments. Furthermore, two molecules of U74500 appear to be involved in each transfer event. Our results show that relatively simple principles govern the delivery of compounds from oil-in-water emulsions to cells.
Collapse
Affiliation(s)
- D E Decker
- Upjohn Laboratories, Cell Biology and Inflammation Research, Kalamazoo MI 49001, USA
| | | | | | | | | |
Collapse
|
20
|
Milstien S, Sakai N, Kaufman S, Saito K, Heyes MP. Role of tetrahydrobiopterin in cytokine-stimulated metabolism of tryptophan and hydroxylation of arginine. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 338:289-94. [PMID: 8304126 DOI: 10.1007/978-1-4615-2960-6_60] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- S Milstien
- Laboratories of Neurochemistry, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892
| | | | | | | | | |
Collapse
|
21
|
Eastman CL, Guilarte TR, Lever JR. Uptake of 3-hydroxykynurenine measured in rat brain slices and in a neuronal cell line. Brain Res 1992; 584:110-6. [PMID: 1515932 DOI: 10.1016/0006-8993(92)90883-b] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The uptake of 3-hydroxykynurenine (3HK), a tryptophan metabolite with reported convulsant and cytotoxic properties, has been investigated in a neuronally derived hybrid cell line and in tissue slices prepared from rat brain. In both systems, the observed uptake was temperature-dependent and inhibited in the presence of large neutral amino acids. The apparent Km and Vmax determined for 3HK uptake into N18-RE-105 cells were 1.65 mM and 25.5 nmol/(min x mg protein), respectively. The uptake of 3HK into rat brain slices could be resolved into two components on the basis of their requirements for sodium. Kinetic analyses performed using hippocampal slices revealed a Km of 1.1 mM and Vmax of 18.8 nmol/(h x mg protein) for the sodium-independent process and a Km of 4.8 mM and Vmax of 54.5 nmol/(h x mg protein) for the sodium-dependent process. While sodium-dependent uptake was abolished following treatment with metabolic inhibitors, sodium-independent uptake was only slightly impaired. Sodium-independent uptake was inhibited in the presence of the non-metabolizable amino acids, aminoisobutyric acid (AIB) and aminobicyclo(2,2,1)heptane-2-carboxylic acid (BCH), but not by N-methylated amino acid substrates. Sodium-dependent uptake was insensitive to AIB and was completely abolished by BCH. These results indicate that an uptake process for 3HK is present in the mammalian brain, and suggest that the sodium-dependent component of 3HK transport may be mediated by a system which has not previously been described in CNS tissue.
Collapse
Affiliation(s)
- C L Eastman
- Department of Environmental Health Sciences, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD 21205
| | | | | |
Collapse
|
22
|
Structure of the gene for the neuronal intermediate filament protein alpha-internexin and functional analysis of its promoter. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55018-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
23
|
Coyle JT, Murphy TH, Puttfarcken PS, Lyons EW, Vornov JJ. The non-excitatory mechanisms of glutamate induced neurotoxicity. Epilepsy Res 1991; 10:41-8. [PMID: 1686428 DOI: 10.1016/0920-1211(91)90093-u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J T Coyle
- Department of Psychiatry, Johns Hopkins University, Baltimore, MD
| | | | | | | | | |
Collapse
|
24
|
Eastman CL, Guilarte TR. The role of hydrogen peroxide in the in vitro cytotoxicity of 3-hydroxykynurenine. Neurochem Res 1990; 15:1101-7. [PMID: 2089269 DOI: 10.1007/bf01101711] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Previous studies have indicated that the generation of H2O2 may be a key step in the mechanism mediating the in vitro cytotoxicity of 3-hydroxykynurenine (3HK). An exposure protocol resulting in a delayed toxicity was utilized in order to further examine the role of H2O2 in the in vitro toxicity of 3HK in a neural hybrid cell line. 3HK-induced cell lysis was significantly attenuated by administration of catalase after termination of 3HK exposure and was abolished when intracellular peroxidase activity was elevated by pretreatment of cultures with horseradish peroxidase. In addition, a dose-dependent attenuation of 3HK toxicity was observed when cultures were exposed to 3HK in the presence of the iron chelator, desferrioxamine (DFO). Pretreatment with DFO also resulted in a significant attenuation of 3HK toxicity. These data suggest a direct role for H2O2 and metal ions in the cytotoxic action of 3HK and indicate that cell lysis results from the intracellular accumulation of toxic levels of H2O2.
Collapse
Affiliation(s)
- C L Eastman
- Dept. of Environmental Health Science, Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD 21205
| | | |
Collapse
|
25
|
Simantov R. gamma-Aminobutyric acid (GABA) enhances glutamate cytotoxicity in a cerebellar cell line. Brain Res Bull 1990; 24:711-5. [PMID: 1973624 DOI: 10.1016/0361-9230(90)90127-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A temperature-sensitive rat cerebellar cell line SC9 has been used to study the role of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in glutamate cytotoxicity. GABA increases glutamate toxicity in a dose-dependent fashion, but NMDA and kainic acid were not toxic in the presence or absence of GABA. The specificity of this cytotoxicity was further indicated by the NMDA-selective antagonist 2-amino-7-phosphonoheptanoic acid (APV), which does not block glutamate effect. These observations, as well as binding experiments with 3H-glutamate, suggest that glutamate cytotoxicity in these cells depends on quisqualate-selective uptake sites of the amino acid. The study may open therefore a novel pathway for understanding the cytotoxic effect of excitatory amino acids in brain structures that are enriched with GABA and glutamate uptake sites.
Collapse
Affiliation(s)
- R Simantov
- Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
26
|
Abstract
The toxicity of 3-hydroxykynurenine (3HK), an endogenous tryptophan metabolite which is markedly elevated in rat CNS tissue as a result of neonatal vitamin B-6 deficiency, was investigated in a neuronally derived hybrid cell line (N18-RE-105). At concentrations in excess of 100 microM, 3HK was toxic to greater than 85% of cultured cells over the course of 24 h. The time course of 3HK toxicity was studied in cultures exposed to 500 microM 3HK. Cell lysis proceeded linearly to completion in 8-12 h, but the toxic effects of exposure for 2 h were irreversible. 3HK was the most potently toxic among several related kynurenine metabolites tested. The toxic effects of 3HK exposure were markedly attenuated or abolished in the presence of either catalase or glutathione, indicating, a role of oxidative stress in 3HK toxicity.
Collapse
Affiliation(s)
- C L Eastman
- Department of Environmental Health Sciences, Johns Hopkins University School of Hygiene and Public Health, Baltimore, MD 21205
| | | |
Collapse
|
27
|
Murphy TH, Miyamoto M, Sastre A, Schnaar RL, Coyle JT. Glutamate toxicity in a neuronal cell line involves inhibition of cystine transport leading to oxidative stress. Neuron 1989; 2:1547-58. [PMID: 2576375 DOI: 10.1016/0896-6273(89)90043-3] [Citation(s) in RCA: 758] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glutamate binds to both excitatory neurotransmitter binding sites and a Cl(-)-dependent, quisqualate- and cystine-inhibited transport site on brain neurons. The neuroblastoma-primary retina hybrid cells (N18-RE-105) are susceptible to glutamate-induced cytotoxicity. The Cl(-)-dependent transport site to which glutamate and quisqualate (but not kainate or NMDA) bind has a higher affinity for cystine than for glutamate. Lowering cystine concentrations in the cell culture medium results in cytotoxicity similar to that induced by glutamate addition in its morphology, kinetics, and Ca2+ dependence. Glutamate-induced cytotoxicity is directly proportional to its ability to inhibit cystine uptake. Exposure to glutamate (or lowered cystine) causes a decrease in glutathione levels and an accumulation of intracellular peroxides. Like N18-RE-105 cells, primary rat hippocampal neurons (but not glia) in culture degenerate in medium with lowered cystine concentration. Thus, glutamate-induced cytotoxicity in N18-RE-105 cells is due to inhibition of cystine uptake, resulting in lowered glutathione levels leading to oxidative stress and cell death.
Collapse
Affiliation(s)
- T H Murphy
- Department of Pharmacology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | | | | | | |
Collapse
|
28
|
Wilmot CA. Excitatory amino acid antagonists: Behavioral and biochemical approaches for the development of new central nervous system therapeutic agents. Drug Dev Res 1989. [DOI: 10.1002/ddr.430170409] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
29
|
Berry BW, Boland LM, Hoch DB, Dingledine R. L-glutamate binding site on N18-RE-105 neuroblastoma hybrid cells is not coupled to an ion channel. J Neurochem 1988; 51:1176-83. [PMID: 2458433 DOI: 10.1111/j.1471-4159.1988.tb03084.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We studied the properties of the N18-RE-105 neuronal cell line to determine if its glutamate binding site represents a neurotransmitter receptor. In immunocytochemical experiments, these cells stained strongly for neurofilament, but not for glial fibrillary acidic protein. In whole-cell patch clamp experiments, cells exhibited voltage-dependent Na+, Ca2+, and K+ currents characteristic of neurons. However, perfusion with L-glutamate or other excitatory amino acids did not evoke the inward current expected of a receptor/channel complex. In binding studies, the maximum accumulation of L-[3H]glutamate by washed membrane vesicles at 37 degrees C was 69 pmol/mg protein, and half-maximal accumulation occurred at 0.64 microM. This accumulation was blocked completely by quisqualate, partially by DL-2-amino-4-phosphonobutyric acid and L-cystine, but not at all by 1 mM kainate or N-methylaspartate. L-[3H]Glutamate accumulation was stimulated by Cl-, but reduced by Na+, 0.01% digitonin, or hyperosmotic (400 mM glucose) assay medium. The release of L-[3H]glutamate from vesicles was much faster in the presence of 100 microM unlabelled glutamate than 100 microM unlabelled quisqualate or DL-2-amino-4-phosphonobutyric acid. Thus, although N18-RE-105 cells possess many neuronal properties, the results obtained are not those expected from reversible binding of L-glutamate to a receptor/channel complex, but are consistent with a Cl- -stimulated sequestration or exchange process.
Collapse
Affiliation(s)
- B W Berry
- Department of Pharmacology and Neurobiology Curriculum, University of North Carolina, Chapel Hill 27599-7365
| | | | | | | |
Collapse
|
30
|
Murphy TH, Schnaar RL, Coyle JT, Sastre A. Glutamate cytotoxicity in a neuronal cell line is blocked by membrane depolarization. Brain Res 1988; 460:155-60. [PMID: 2905921 DOI: 10.1016/0006-8993(88)91216-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To understand better the proximate mechanism involved in the excitotoxic response to L-glutamate (Glu), we have exploited the Glu receptor present in the N18-RE-105 neuroblastoma-embryonic retinal hybrid cell line. These cells undergo lysis dependent on extracellular Ca2+ when exposed to Glu. We now report that the depolarizing action of Glu is not responsible for its cytotoxic effects. Furthermore, depolarization of these cells with elevated K+, ouabain or veratridine does not cause cytotoxicity but rather protects against the cytotoxic effects of Glu. Our results may implicate a role for voltage-sensitive Ca2+ channels (VSCCs) in cytotoxicity, and depolarization-induced inactivation of VSCCs (Nature (Lond.), 316 (1985) 440-443) as a protection against Glu receptor agonists. Our findings demonstrate a clear dissociation between depolarization and the neuronal degeneration caused by Glu.
Collapse
Affiliation(s)
- T H Murphy
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | | | | | | |
Collapse
|
31
|
Murphy TH, Malouf AT, Sastre A, Schnaar RL, Coyle JT. Calcium-dependent glutamate cytotoxicity in a neuronal cell line. Brain Res 1988; 444:325-32. [PMID: 2896063 DOI: 10.1016/0006-8993(88)90941-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Membranes from the neuroblastoma x embryonic retina cell hybrid cell line, N18-RE-105, bind L-[3H]glutamate with a pharmacologic profile consistent with a 'quisqualate-type' brain L-glutamate receptor. We describe here the cytotoxic effect of L-glutamate receptor agonists on intact N18-RE-105 cells. Cytotoxicity was quantitated by measurement of the release of the cytosolic enzyme, lactate dehydrogenase, into the culture medium after addition of L-glutamate and its analogs to the cell culture medium. L-Glutamate (10 mM) and its confirmationally restricted analogs, quisqualate (1 mM) and ibotenate (10 mM), caused cell lysis. In contrast, similar analogs which do not bind to N18-RE-105 cell membranes (kainic acid, N-methyl-D,L-aspartic acid and gamma-aminobutyric acid) were not cytotoxic. L-Glutamate-induced cytotoxicity was eliminated when calcium-free medium was used. Addition of inorganic or organic calcium channel antagonists also reduced the cytotoxicity of L-glutamate, even when 1.8 mM calcium was present in the medium. Cadmium chloride (10 microM) completely blocked L-glutamate toxicity, whereas manganese chloride (150 microM) and lanthanum chloride (25 microM) reduced toxicity by greater than 50%. Dihydropyridine voltage-sensitive calcium channel agonists or antagonists, had little or no significant effect on L-glutamate-induced toxicity. In contrast, the verapamil derivatives, D600 and D888, and the diltiazem derivative, MDL 12,330A reduced L-glutamate toxicity by greater than 50%. These results suggest that a subtype of voltage-sensitive calcium channels is involved in the mechanism of L-glutamate receptor mediated cytotoxicity in this cell line.
Collapse
Affiliation(s)
- T H Murphy
- Department of Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | | | | | | | | |
Collapse
|
32
|
Govitrapong P, Ebadi M. The inhibition of pineal arylalkylamine n-acetyltransferase by glutamic acid and its analogues. Neurochem Int 1988; 13:223-30. [DOI: 10.1016/0197-0186(88)90058-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/1988] [Accepted: 03/09/1988] [Indexed: 12/22/2022]
|
33
|
Abstract
Some neurochemical characteristics of [3H]L-glutamic acid binding sites were studied using membranous homogenate preparations obtained from the rat adrenal. It was found that the binding was inhibited by the addition (10(-7)-10(-3) M) of L-isomers of structure-related compounds in a concentration-dependent manner. A significant inhibition of the binding was induced by L-glutamic acid diethylester, but not by alpha-aminoadipic acid. Scatchard analysis revealed that the binding sites consisted of a single component with a Kd of 0.19 +/- 0.05 microM and a Bmax of 4.11 +/- 0.71 pmol/mg protein, respectively. In vitro addition of sodium acetate (1-100 mM) elicited a stimulatory action on the binding at 2 degrees C, while inducing a significant attenuation of the binding at 30 degrees C. The binding reached a plateau within 30 min of incubation followed by a gradual decline up to 60 min in the presence of 100 mM sodium acetate at 30 degrees C, whereas the binding continued to increase up to 60 min in the absence of sodium acetate. Addition (0.1-10 mM) of N-methyl-D-aspartic acid (NMDA), one of the agonists for central excitatory amino acid neurotransmitter receptors, exerted a significant augmentation of the adrenal binding independently of the incubation temperature in a concentration-dependent manner. The latter facilitation of the binding, however, was not affected by the classical antagonists for central NMDA receptors such as 2-amino-5-phosphonovaleric acid and 2-amino-7-phosphonoheptanoic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
34
|
Abstract
A significant activity of L-[3H]glutamic acid binding was detected in the membranous particulate preparations obtained from the rat adrenal glands. In vitro addition of sodium acetate (100 mM) resulted in a drastic enhancement of the binding to cerebral preparations, while inducing a significant inhibition of the adrenal binding. Quisqualic acid elicited a prominent suppression of the adrenal binding in a concentration-dependent manner to a slightly greater extent than the inhibition of cerebral binding. N-Methyl-D-aspartic acid exerted a significant stimulatory action on the adrenal binding without affecting the cerebral binding. The adrenal medullary part possessed more than 5-fold higher binding activity than that in cortical part. These results suggest the possible existence of [3H]glutamate binding sites in rat adrenal glands which are distinctly different from those in the central structures.
Collapse
|
35
|
Abstract
A significant activity of [3H]glutamate binding was detected in homogenate particulate preparations obtained from the rat pituitary, in addition to central structures including the cerebral cortex. In contrast to the cerebral binding, the pituitary binding was significantly inhibited by Na+ ions. It was also found that neurohypophysis possessed more than a two-fold higher binding activity than that found in adenohypophysis. These results suggest a possible significance of glutamate in rodent pituitary.
Collapse
|
36
|
Govitrapong P, Ebadi M, Murrin LC. Identification of a Cl-/Ca2+-dependent glutamate (quisqualate) binding site in bovine pineal organ. J Pineal Res 1986; 3:223-34. [PMID: 3534213 DOI: 10.1111/j.1600-079x.1986.tb00745.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The presence of a high concentration of glutamic acid, a transmitter shown to have excitatory action in the pineal organ, prompted us to search for and to characterize glutamate receptor site in the bovine pineal organ. By using 10 nM- 100 microM of labeled and unlabeled L-glutamate and by employing the LIGAND computer program, we found a glutamate binding site with a dissociation equilibrium constant (KD) of 0.534 microM and a receptor density (Bmax) of 4.84 pmol/mg protein. This pH- and temperature-dependent binding site showed stereospecificity, was activated by Ca2+, and displayed affinity for both glutamate agonists and antagonists. The IC50 values for L-glutamate, L-aspartate, L-cysteate, L-cysteine sulfinate, quisqualate, and (+/-) ibotenate were 0.5, 2, 12, 16, 25, and 30 microM, respectively, whereas those for D-aspartate, L-alpha-aminoadipate, L-homocysteate, and DL(+/-) 2-amino-4-phosphonobutyrate were greater than 100 microM. Kainate, N-methyl-D-aspartate, and L-glutamic acid diethyl ester were inactive. Based on these results, the presence of a quisqualate-type, Cl-/Ca2+-dependent glutamate binding site in the pineal organ is suggested, and a possible neuroexcitatory role for glutamic acid, aspartic acid, and certain sulfur-containing amino acids is also implied. The precise nature of this excitatory effect in modulating the function(s) of the pineal organ and the synthesis of its hormone(s) remains to be elucidated.
Collapse
|
37
|
Possible interaction of [3H]glutamate binding sites with anion channels in rat neural tissues. Neurochem Int 1986; 9:521-31. [DOI: 10.1016/0197-0186(86)90145-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/1986] [Accepted: 05/06/1986] [Indexed: 11/21/2022]
|
38
|
Malouf AT, Coyle JT, Schnaar RL. Agonists and cations regulate the glutamic acid receptors on intact neuroblastoma hybrid cells. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90811-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|