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Rahimmi A, Tozandehjani S, Daraei M, Khademerfan M. The neuroprotective roles of Dietary Micronutrients on Parkinson’s disease: a review. Mol Biol Rep 2022; 49:8051-8060. [DOI: 10.1007/s11033-022-07345-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 12/01/2022]
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Shen D, Tian L, Yang F, Li J, Li X, Yao Y, Lam EWF, Gao P, Jin B, Wang R. ADO/hypotaurine: a novel metabolic pathway contributing to glioblastoma development. Cell Death Discov 2021; 7:21. [PMID: 33483477 PMCID: PMC7822925 DOI: 10.1038/s41420-020-00398-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/09/2020] [Accepted: 12/15/2020] [Indexed: 01/07/2023] Open
Abstract
Significant advance has been made towards understanding glioblastoma metabolism through global metabolomic profiling. However, hitherto little is known about the role by which altered metabolism plays in driving the aggressive glioma phenotype. We have previously identified hypotaurine as one of the top-ranked metabolites for differentiating low- and high-grade tumors, and that there is also a strong association between the levels of intratumoral hypotaurine and expression of its biosynthetic enzyme, cysteamine (2-aminoethanethiol) dioxygenase (ADO). Using transcription profiling, we further uncovered that the ADO/hypotaurine axis targets CCL20 secretion through activating the NF-κB pathway to drive the self-renewal and maintenance of glioma 'cancer stem cells' or glioma cancer stem-like cells. Conversely, abrogating the ADO/hypotaurine axis using CRISPR/Cas9-mediated gene editing limited glioblastoma cell proliferation and self-renewal in vitro and tumor growth in vivo in an orthotopical mouse model, indicating that this metabolic pathway is a potential key therapeutic target. Collectively, our results unveil a targetable metabolic pathway, which contributes to the growth and progression of aggressive high-grade gliomas, as well as a novel predictive marker for glioblastoma diagnosis and therapy.
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Affiliation(s)
- Dachuan Shen
- Department of Oncology, Affiliated Zhongshan Hospital of Dalian University, 116001, Dalian, Liaoning, P.R. China
| | - Lili Tian
- Department of Oncology, First Affiliated Hospital of Dalian Medical University, 116011, Dalian, Liaoning, P.R. China
| | - Fangyu Yang
- Department of Neurosurgery, General Hospital of Northern Theater Command, 110015, Shenyang, Liaoning, P.R. China
| | - Jun Li
- Department of Neurosurgery, First Affiliated Hospital of Dalian Medical University, 116011, Dalian, Liaoning, P.R. China
| | - Xiaodong Li
- Institute of Cancer Stem Cell, Cancer Center, Dalian Medical University, 116044, Dalian, Liaoning, P.R. China
| | - Yiqun Yao
- Department of Thyroid and Breast Surgery, Affiliated Zhongshan Hospital of Dalian University, 116001, Dalian, Liaoning, P.R. China
| | - Eric W-F Lam
- Department of Surgery and Cancer, Imperial College London, London, W12 0NN, UK
| | - Peng Gao
- Clinical Laboratory, Dalian Sixth People's Hospital, 116031, Dalian, Liaoning, P.R. China.
| | - Bilian Jin
- Institute of Cancer Stem Cell, Cancer Center, Dalian Medical University, 116044, Dalian, Liaoning, P.R. China.
| | - Ruoyu Wang
- Department of Oncology, Affiliated Zhongshan Hospital of Dalian University, 116001, Dalian, Liaoning, P.R. China.
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Malatji BG, Meyer H, Mason S, Engelke UFH, Wevers RA, van Reenen M, Reinecke CJ. A diagnostic biomarker profile for fibromyalgia syndrome based on an NMR metabolomics study of selected patients and controls. BMC Neurol 2017; 17:88. [PMID: 28490352 PMCID: PMC5426044 DOI: 10.1186/s12883-017-0863-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 04/26/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Fibromyalgia syndrome (FMS) is a chronic pain syndrome. A plausible pathogenesis of the disease is uncertain and the pursuit of measurable biomarkers for objective identification of affected individuals is a continuing endeavour in FMS research. Our objective was to perform an explorative metabolomics study (1) to elucidate the global urinary metabolite profile of patients suffering from FMS, and (2) to explore the potential of this metabolite information to augment existing medical practice in diagnosing the disease. METHODS We selected patients with a medical history of persistent FMS (n = 18), who described their recent state of the disease through the Fibromyalgia Impact Questionnaire (FIQR) and an in-house clinical questionnaire (IHCQ). Three control groups were used: first-generation family members of the patients (n = 11), age-related individuals without any indications of FMS or related conditions (n = 10), and healthy young (18-22 years) individuals (n = 20). All subjects were female and the biofluid under investigation was urine. Correlation analysis of the FIQR showed the FMS patients represented a well-defined disease group for this metabolomics study. Spectral analyses of urine were conducted using a 500 MHz 1H nuclear magnetic resonance (NMR) spectrometer; data processing and analyses were performed using Matlab, R, SPSS and SAS software. RESULTS AND DISCUSSION Unsupervised and supervised multivariate analyses distinguished all three control groups and the FMS patients, and significant increases in metabolites related to the gut microbiome (hippuric, succinic and lactic acids) were observed. We have developed an algorithm for the diagnosis of FMS consisting of three metabolites - succinic acid, taurine and creatine - that have a good level of diagnostic accuracy (Receiver Operating Characteristic (ROC) analysis - area under the curve 90%) and on the pain and fatigue symptoms for the selected FMS patient group. CONCLUSION Our data and comparative analyses indicated an altered metabolic profile of patients with FMS, analytically detectable within their urine. Validation studies may substantiate urinary metabolites to supplement information from medical assessment, tender-point measurements and FIQR questionnaires for an improved objective diagnosis of FMS.
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Affiliation(s)
- Bontle G Malatji
- Centre for Human Metabolomics, Faculty of Natural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Helgard Meyer
- Department of Family Medicine, Kalafong Hospital, University of Pretoria, Private Bag X396, Pretoria, South Africa
| | - Shayne Mason
- Centre for Human Metabolomics, Faculty of Natural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Udo F H Engelke
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Mari van Reenen
- Centre for Human Metabolomics, Faculty of Natural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Carolus J Reinecke
- Centre for Human Metabolomics, Faculty of Natural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa.
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Ferreira L, Pereira L, Faria R. Fluorescent dyes as a reliable tool in P2X7 receptor-associated pore studies. J Bioenerg Biomembr 2015; 47:283-307. [PMID: 26076670 DOI: 10.1007/s10863-015-9613-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 05/27/2015] [Indexed: 01/09/2023]
Abstract
Since the nineteenth century, a great amount of different biological structures and processes have been assessed by fluorescent dyes. Along with the uses of these compounds as vital and histological dyes, some fluorescent dyes have become valuable tools for the study of the pore phenomenon in plasma membranes. Some ion channels capable of forming large conductance channels, such as P2X7, TRPV1, VDAC-1 and the maxi-anion channels transiently alter the plasma membrane permeability, producing pores, which permit the passage of molecules of up to 1,000 Da. In this review, we discuss the uses of the fluorescent dyes chosen in diverse studies of this topic up to now.
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Affiliation(s)
- Leonardo Ferreira
- Laboratory of Cellular Communication, Oswaldo Cruz Foundation, Av. Brazil 4365, pavilion 108, room 28B Manguinhos, Rio de Janeiro, Brazil, CEP 21040-360,
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Abstract
Hydrogen sulfide (H₂S) has emerged as an important signaling molecule with beneficial effects on various cellular processes affecting, for example, cardiovascular and neurological functions. The physiological importance of H₂S is motivating efforts to develop strategies for modulating its levels. However, advancement in the field of H₂S-based therapeutics is hampered by fundamental gaps in our knowledge of how H₂S is regulated, its mechanism of action, and its molecular targets. This review provides an overview of sulfur metabolism; describes recent progress that has shed light on the mechanism of H₂S as a signaling molecule; and examines nutritional regulation of sulfur metabolism, which pertains to health and disease.
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Affiliation(s)
- Omer Kabil
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0600;
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Abstract
Taurine (2-aminoethanesulfonic acid) is widely distributed in animal tissues and has
diverse pharmacological effects. However, the role of taurine in modulating smooth
muscle contractility is still controversial. We propose that taurine (5-80 mM) can
exert bidirectional modulation on the contractility of isolated rat jejunal segments.
Different low and high contractile states were induced in isolated jejunal segments
of rats to observe the effects of taurine and the associated mechanisms. Taurine
induced stimulatory effects on the contractility of isolated rat jejunal segments at
3 different low contractile states, and inhibitory effects at 3 different high
contractile states. Bidirectional modulation was not observed in the presence of
verapamil or tetrodotoxin, suggesting that taurine-induced bidirectional modulation
is Ca2+ dependent and requires the presence of the enteric nervous system.
The stimulatory effects of taurine on the contractility of isolated jejunal segments
was blocked by atropine but not by diphenhydramine or by cimetidine, suggesting that
muscarinic-linked activation was involved in the stimulatory effects when isolated
jejunal segments were in a low contractile state. The inhibitory effects of taurine
on the contractility of isolated jejunal segments were blocked by propranolol and
L-NG-nitroarginine but not by phentolamine, suggesting that adrenergic β receptors
and a nitric oxide relaxing mechanism were involved when isolated jejunal segments
were in high contractile states. No bidirectional effects of taurine on myosin
phosphorylation were observed. The contractile states of jejunal segments determine
taurine-induced stimulatory or inhibitory effects, which are associated with
muscarinic receptors and adrenergic β receptors, and a nitric oxide associated
relaxing mechanism.
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Affiliation(s)
- Q Y Yao
- Dalian Medical University, Dalian, Liaoning, China
| | - D P Chen
- Dalian Medical University, Dalian, Liaoning, China
| | - D M Ye
- Dalian Medical University, Dalian, Liaoning, China
| | - Y P Diao
- Dalian Medical University, Dalian, Liaoning, China
| | - Y Lin
- Dalian Medical University, Dalian, Liaoning, China
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Waszkielewicz AM, Gunia A, Szkaradek N, Słoczyńska K, Krupińska S, Marona H. Ion channels as drug targets in central nervous system disorders. Curr Med Chem 2013; 20:1241-85. [PMID: 23409712 PMCID: PMC3706965 DOI: 10.2174/0929867311320100005] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 01/14/2013] [Accepted: 01/18/2013] [Indexed: 12/27/2022]
Abstract
Ion channel targeted drugs have always been related with either the central nervous system (CNS), the peripheral nervous system, or the cardiovascular system. Within the CNS, basic indications of drugs are: sleep disorders, anxiety, epilepsy, pain, etc. However, traditional channel blockers have multiple adverse events, mainly due to low specificity of mechanism of action. Lately, novel ion channel subtypes have been discovered, which gives premises to drug discovery process led towards specific channel subtypes. An example is Na(+) channels, whose subtypes 1.3 and 1.7-1.9 are responsible for pain, and 1.1 and 1.2 - for epilepsy. Moreover, new drug candidates have been recognized. This review is focusing on ion channels subtypes, which play a significant role in current drug discovery and development process. The knowledge on channel subtypes has developed rapidly, giving new nomenclatures of ion channels. For example, Ca(2+)s channels are not any more divided to T, L, N, P/Q, and R, but they are described as Ca(v)1.1-Ca(v)3.3, with even newer nomenclature α1A-α1I and α1S. Moreover, new channels such as P2X1-P2X7, as well as TRPA1-TRPV1 have been discovered, giving premises for new types of analgesic drugs.
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Affiliation(s)
- A M Waszkielewicz
- Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Krakow, Poland.
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8
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Menzie J, Prentice H, Wu JY. Neuroprotective Mechanisms of Taurine against Ischemic Stroke. Brain Sci 2013; 3:877-907. [PMID: 24961429 PMCID: PMC4061860 DOI: 10.3390/brainsci3020877] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/14/2013] [Accepted: 05/17/2013] [Indexed: 02/02/2023] Open
Abstract
Ischemic stroke exhibits a multiplicity of pathophysiological mechanisms. To address the diverse pathophysiological mechanisms observed in ischemic stroke investigators seek to find therapeutic strategies that are multifaceted in their action by either investigating multipotential compounds or by using a combination of compounds. Taurine, an endogenous amino acid, exhibits a plethora of physiological functions. It exhibits antioxidative properties, stabilizes membrane, functions as an osmoregulator, modulates ionic movements, reduces the level of pro-inflammators, regulates intracellular calcium concentration; all of which contributes to its neuroprotective effect. Data are accumulating that show the neuroprotective mechanisms of taurine against stroke pathophysiology. In this review, we describe the neuroprotective mechanisms employed by taurine against ischemic stroke and its use in clinical trial for ischemic stroke.
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Affiliation(s)
- Janet Menzie
- Program in Integrative Biology, Florida Atlantic University, Boca Raton, FL 33431, USA.
| | - Howard Prentice
- Department of Biomedical Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA.
| | - Jang-Yen Wu
- Program in Integrative Biology, Florida Atlantic University, Boca Raton, FL 33431, USA.
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Abstract
Glutamate (GLU)-induced excitotoxicity is considered to be a frequent cause of cell degeneration in basal ganglia disorders; it is normally prevented by uptake of GLU by astrocytes. We recently found that transient perfusion of GLU in the striatum induces persistent accumulation of GLU in striatal astrocytes that could be from the initial administration or caused by the slow release from neurons or astrocytes in response to it. Endogenous production of GLU, that is, "self-induced GLU accumulation" (SIGA), may occur under physiological and pathological conditions. Here we studied the possible induction of SIGA after injury induced by perfusion of GLU receptor agonists into the striatum of rats. The agonists induced local degeneration in neurons and myelinated axons and microgliosis and astrocytosis; there was also gliosis and remote degeneration of neurons in the ventral-posterior complex of the thalamus that project to the cerebral cortex across the striatum. Reactive astrocytes showed persistent GLU accumulation in the striatum (local SIGA) and thalamus (remote SIGA) that persisted for at least 6 weeks after the injury. Thus, SIGA can be induced by neuronal degeneration retrogradely triggered from a remote brain region after excessive release of endogenous GLU from astrocytes. This may be an additional factor to be considered in basal ganglia disorders with glutamatergic excitotoxicity.
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10
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Mu-rhythm changes during the planning of motor and motor imagery actions. Neuropsychologia 2013; 51:1019-26. [DOI: 10.1016/j.neuropsychologia.2013.02.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 02/05/2013] [Accepted: 02/14/2013] [Indexed: 11/20/2022]
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Rodriguez M, Sabate M, Rodriguez-Sabate C, Morales I. The role of non-synaptic extracellular glutamate. Brain Res Bull 2012; 93:17-26. [PMID: 23149167 DOI: 10.1016/j.brainresbull.2012.09.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/07/2012] [Accepted: 09/12/2012] [Indexed: 12/21/2022]
Abstract
Although there are some mechanisms which allow the direct crossing of substances between the cytoplasm of adjacent cells (gap junctions), most substances use the extracellular space to diffuse between brain cells. The present work reviews the behavior and functions of extracellular glutamate (GLU). There are two extracellular pools of glutamate (GLU) in the brain, a synaptic pool whose functions in the excitatory neurotransmission has been widely studied and an extrasynaptic GLU pool although less known nonetheless is gaining attention among a growing number of researchers. Evidence accumulated over the last years shows a number of mechanisms capable of releasing glial GLU to the extracellular medium, thus modulating neurons, microglia and oligodendrocytes, and regulating the immune response, cerebral blood flow, neuronal synchronization and other brain functions. This new scenario is expanding present knowledge regarding the role of GLU in the brain under different physiological and pathological conditions. This article is part of a Special Issue entitled 'Extrasynaptic ionotropic receptors'.
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Affiliation(s)
- Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La Laguna, La Laguna, Tenerife, Canary Islands, Spain.
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12
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Menzie J, Pan C, Prentice H, Wu JY. Taurine and central nervous system disorders. Amino Acids 2012; 46:31-46. [DOI: 10.1007/s00726-012-1382-z] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 07/27/2012] [Indexed: 01/28/2023]
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Burnstock G, Krügel U, Abbracchio MP, Illes P. Purinergic signalling: from normal behaviour to pathological brain function. Prog Neurobiol 2011; 95:229-74. [PMID: 21907261 DOI: 10.1016/j.pneurobio.2011.08.006] [Citation(s) in RCA: 314] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 02/07/2023]
Abstract
Purinergic neurotransmission, involving release of ATP as an efferent neurotransmitter was first proposed in 1972. Later, ATP was recognised as a cotransmitter in peripheral nerves and more recently as a cotransmitter with glutamate, noradrenaline, GABA, acetylcholine and dopamine in the CNS. Both ATP, together with some of its enzymatic breakdown products (ADP and adenosine) and uracil nucleotides are now recognised to act via P2X ion channels and P1 and P2Y G protein-coupled receptors, which are widely expressed in the brain. They mediate both fast signalling in neurotransmission and neuromodulation and long-term (trophic) signalling in cell proliferation, differentiation and death. Purinergic signalling is prominent in neurone-glial cell interactions. In this review we discuss first the evidence implicating purinergic signalling in normal behaviour, including learning and memory, sleep and arousal, locomotor activity and exploration, feeding behaviour and mood and motivation. Then we turn to the involvement of P1 and P2 receptors in pathological brain function; firstly in trauma, ischemia and stroke, then in neurodegenerative diseases, including Alzheimer's, Parkinson's and Huntington's, as well as multiple sclerosis and amyotrophic lateral sclerosis. Finally, the role of purinergic signalling in neuropsychiatric diseases (including schizophrenia), epilepsy, migraine, cognitive impairment and neuropathic pain will be considered.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
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Vitvitsky V, Garg SK, Banerjee R. Taurine biosynthesis by neurons and astrocytes. J Biol Chem 2011; 286:32002-10. [PMID: 21778230 DOI: 10.1074/jbc.m111.253344] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The physiological roles of taurine, a product of cysteine degradation and one of the most abundant amino acids in the body, remain elusive. Taurine deficiency leads to heart dysfunction, brain development abnormalities, retinal degradation, and other pathologies. The taurine synthetic pathway is proposed to be incomplete in astrocytes and neurons, and metabolic cooperation between these cell types is reportedly needed to complete the pathway. In this study, we analyzed taurine synthesis capability as reported by incorporation of radioactivity from [(35)S]cysteine into taurine, in primary murine astrocytes and neurons, and in several transformed cell lines (human (SH-SY5Y) and murine (N1E-115) neuroblastoma, human astrocytoma (U-87 MG and 1321 N1), and rat glioma (C6)). Extensive incorporation of radioactivity from [(35)S]cysteine into taurine was observed in rat glioma cells as well as in primary mouse astrocytes and neurons, establishing the presence of an intact taurine synthesis pathway in these cells. Interestingly, exposure of cells to cysteine or cysteamine resulted in elevated intracellular hypotaurine without a corresponding increase in taurine levels, suggesting that oxidation of hypotaurine limits taurine synthesis in cells. Consistent with its role as an organic osmolyte, taurine synthesis was stimulated under hypertonic conditions in neurons.
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Affiliation(s)
- Victor Vitvitsky
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, USA
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15
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Gao X, Yang X, Zhang B. Neuroprotection of taurine against bilirubin-induced elevation of apoptosis and intracellular free calcium ion in vivo. Toxicol Mech Methods 2011; 21:383-7. [PMID: 21250777 DOI: 10.3109/15376516.2010.546815] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Previous work has shown that taurine protected neurons against unconjugated bilirubin (UCB)-induced neurotoxicity by preventing cell apoptosis and maintaining intracellular Ca²⁺ homeostasis in primary neuron culture. This study investigates the neurotoxicity of hyperbilirubinemia and neuroprotection of taurine in a clinically relevant murine model in vivo. A hyperbilirubinemia baby mice model was established by intraperitoneal injection with UCB. After 24 h, the neural apoptotic level, transcriptional activity of caspase-3, and iCa²⁺ concentration were detected. It was found that UCB injection significantly increased both intracellular free Ca²⁺ concentrations and the activities of proapoptosis protease caspase-3, which is related to the elevation of neural apoptosis level. When baby mice were pretreated with 7.5 or 15 mg/kg body weight (bw) taurine for 4 h and then exposed to UCB, apoptotic death was significantly attenuated through down-regulation of activity of caspase-3 and i[Ca²⁺] in the brain. From these observations, it was concluded that taurine limits bilirubin-induced neural damage by inhibiting iCa²⁺ overload as well as decreasing activation of proapoptotic proteases caspase-3. This study might contribute to the development of taurine as a broad-spectrum agent for preventing and/or treating neural damage in neonatal jaundice.
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Affiliation(s)
- Xiaoling Gao
- Molecular Immunology, Center of Clinical laboratory, People's Hospital of Gansu Province, Gansu, P.R. China
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Fisher SK, Heacock AM, Keep RF, Foster DJ. Receptor regulation of osmolyte homeostasis in neural cells. J Physiol 2010; 588:3355-64. [PMID: 20498228 DOI: 10.1113/jphysiol.2010.190777] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The capacity of cells to correct their volume in response to hyposmotic stress via the efflux of inorganic and organic osmolytes is well documented. However, the ability of cell-surface receptors, in particular G-protein-coupled receptors (GPCRs), to regulate this homeostatic mechanism has received much less attention. Mechanisms that underlie the regulation of cell volume are of particular importance to cells in the central nervous system because of the physical restrictions of the skull and the adverse impact that even small increases in cell volume can have on their function. Increases in brain volume are seen in hyponatraemia, which can arise from a variety of aetiologies and is the most frequently diagnosed electrolyte disorder in clinical practice. In this review we summarize recent evidence that the activation of GPCRs facilitates the volume-dependent efflux of osmolytes from neural cells and permits them to more efficiently respond to small, physiologically relevant, reductions in osmolarity. The characteristics of receptor-regulated osmolyte efflux, the signalling pathways involved and the physiological significance of receptor activation are discussed. In addition, we propose that GPCRs may also regulate the re-uptake of osmolytes into neural cells, but that the influx of organic and inorganic osmolytes is differentially regulated. The ability of neural cells to closely regulate osmolyte homeostasis through receptor-mediated alterations in both efflux and influx mechanisms may explain, in part at least, why the brain selectively retains its complement of inorganic osmolytes during chronic hyponatraemia, whereas its organic osmolytes are depleted.
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Affiliation(s)
- Stephen K Fisher
- Molecular and Behavioral Neuroscience Institute, University of Michigan, 5039 Biomedical Sciences Research Building, 109 Zina Pitcher, Ann Arbor, MI 48109-2200, USA.
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Liang J, Deng X, Lin ZX, Zhao LC, Zhang XL. Attenuation of portal hypertension by natural taurine in rats with liver cirrhosis. World J Gastroenterol 2009; 15:4529-37. [PMID: 19777611 PMCID: PMC2751997 DOI: 10.3748/wjg.15.4529] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIM: To investigate the inhibitory effect of natural taurine (NTau) on portal hypertension (PHT) in rats with experimentally-induced liver cirrhosis (LC).
METHODS: Experimentally-induced LC Wistar rats (20 rats/group) were treated with either oral saline or oral NTau for 6 consecutive weeks. Evaluation parameters included portal venous pressure (PVP), portal venous resistance (PVR), portal venous flow (PVF), splanchnic vascular resistance (SVR) and mean arterial pressure (MAP). Vasoactive substance levels including nitric oxide (NO), nitric oxide synthase (NOS) and cyclic guanosine monophosphate (cGMP) were also measured. Histological investigation of type I and III collagen (COL I and III) and transforming growth factor-β1 (TGF-β1) was also performed.
RESULTS: Treatment with NTau (1) significantly decreased PVP, PVR and PVF, and increased MAP and SVP; (2) markedly increased the vascular compliance and reduced the zero-stress of the portal vein; (3) markedly decreased the amount of NO and cGMP and activity of NOS; and (4) improved the pathological status of the liver tissue and reduced the expression of COL I, COL III and TGF-β1.
CONCLUSION: NTau inhibited the LC-induced PHT by improving hyperdynamic circulation, morphology of liver and biomechanical properties of the portal vein in experimentally-induced LC rats.
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Moráles I, Fuentes A, Gonzalez-Hernandez T, Rodríguez M. Osmosensitive response of glutamate in the substantia nigra. Exp Neurol 2009; 220:335-40. [PMID: 19766632 DOI: 10.1016/j.expneurol.2009.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/09/2009] [Accepted: 09/11/2009] [Indexed: 11/18/2022]
Abstract
Previous studies have suggested the increase of extracellular glutamate (GLU) in the substantia nigra (SN) as a cause of dopamine-cell degeneration (excitotoxicity) in Parkinson's disease (PD). However, the mechanisms involved in this increase remain unknown. The present work studied osmoregulation as a cause of GLU release in the SN. Microdialysis was used to change extracellular osmolarity, to administer drugs and to quantify the extracellular non-synaptic GLU (EnS-GLU). Two osmolarity modifications were performed, a moderate decrease (5%) resembling physiological modifications and a substantial decrease (>or=20% decrease) similar to that observed under pathological conditions. Hypo-osmolarity induced a dose-response (285-80 mOsm) increase of EnS-GLU which was detected after small osmolarity modifications (15 mOsm) and which was very marked (>1000%) after more intense osmolarity changes. This response disappeared after pre-treating rats with a P2 purinergic-receptor antagonist (pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid; 1 mM) suggesting ATP involvement in the osmosensitive EnS-GLU response. The EnS-GLU increase observed after administration of ATP (0.1-100 microM) and 2-methylthioadenosine triphosphate tetrasodium (P2-receptor agonist; 100 microM) and the lack of effects of adenosine administration (1 mM) suggest that the ATP action on P2 receptors is an amplificatory mechanism in the osmosensitive EnS-GLU response. The marked action of osmolarity on extracellular Glu suggests osmolarity regulation as a possible source for excitotoxicity in the SN.
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Affiliation(s)
- Ingrid Moráles
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology Faculty of Medicine, University of La Laguna, La Laguna, Tenerife, Canary Islands, Spain
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Leon R, Wu H, Jin Y, Wei J, Buddhala C, Prentice H, Wu JY. Protective function of taurine in glutamate-induced apoptosis in cultured neurons. J Neurosci Res 2009; 87:1185-94. [PMID: 18951478 DOI: 10.1002/jnr.21926] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previously, we showed that taurine protects neurons against glutamate-induced excitotoxicity by inhibiting the glutamate-induced increase of [Ca2+](i). In this study, we report that taurine prevents glutamate-induced chromosomal condensation, indicating that taurine inhibits glutamate-induced apoptosis. We found that Bcl-2 was down-regulated while Bax was up-regulated by glutamate treatment, and these changes were prevented in the presence of taurine. We have also shown that taurine inhibits glutamate-induced activation of calpain. Furthermore, calpastatin, a specific calpain inhibitor, also prevented glutamate-induced cell death. Here we propose the mechanisms underlying glutamate-induced apoptosis and taurine's inhibition of glutamate-induced apoptosis to be as follows: glutamate stimulation induces [Ca2+](i) elevation, which in turn activates calpain; activation of calpain leads to a reduction of Bcl-2:Bax ratios; with decreased Bcl-2:Bax ratios Bax homodimers form, Bax homodimerization, and translocation to the mitochondria result in the release of cytochrome c; released cytochrome c in turn activates a downstream caspase cascade leading to apoptosis. The antiapoptotic function of taurine is due to its inhibition of glutamate-induced membrane depolarization.
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Affiliation(s)
- Rebecca Leon
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida 33431, USA
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Effect of Medium Osmolarity and Taurine on Neuritic Outgrowth from Goldfish Retinal Explants. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009. [DOI: 10.1007/978-0-387-75681-3_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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21
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Haskew-Layton RE, Rudkouskaya A, Jin Y, Feustel PJ, Kimelberg HK, Mongin AA. Two distinct modes of hypoosmotic medium-induced release of excitatory amino acids and taurine in the rat brain in vivo. PLoS One 2008; 3:e3543. [PMID: 18958155 PMCID: PMC2568819 DOI: 10.1371/journal.pone.0003543] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 10/03/2008] [Indexed: 11/19/2022] Open
Abstract
A variety of physiological and pathological factors induce cellular swelling in the brain. Changes in cell volume activate several types of ion channels, which mediate the release of inorganic and organic osmolytes and allow for compensatory cell volume decrease. Volume-regulated anion channels (VRAC) are thought to be responsible for the release of some of organic osmolytes, including the excitatory neurotransmitters glutamate and aspartate. In the present study, we compared the in vivo properties of the swelling-activated release of glutamate, aspartate, and another major brain osmolyte taurine. Cell swelling was induced by perfusion of hypoosmotic (low [NaCl]) medium via a microdialysis probe placed in the rat cortex. The hypoosmotic medium produced several-fold increases in the extracellular levels of glutamate, aspartate and taurine. However, the release of the excitatory amino acids differed from the release of taurine in several respects including: (i) kinetic properties, (ii) sensitivity to isoosmotic changes in [NaCl], and (iii) sensitivity to hydrogen peroxide, which is known to modulate VRAC. Consistent with the involvement of VRAC, hypoosmotic medium-induced release of the excitatory amino acids was inhibited by the anion channel blocker DNDS, but not by the glutamate transporter inhibitor TBOA or Cd2+, which inhibits exocytosis. In order to elucidate the mechanisms contributing to taurine release, we studied its release properties in cultured astrocytes and cortical synaptosomes. Similarities between the results obtained in vivo and in synaptosomes suggest that the swelling-activated release of taurine in vivo may be of neuronal origin. Taken together, our findings indicate that different transport mechanisms and/or distinct cellular sources mediate hypoosmotic medium-induced release of the excitatory amino acids and taurine in vivo.
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Affiliation(s)
- Renée E. Haskew-Layton
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- Burke Medical Research Institute of Cornell University, White Plains, New York, United States of America
| | - Alena Rudkouskaya
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | - Yiqiang Jin
- Ordway Research Institute, Albany, New York, United States of America
| | - Paul J. Feustel
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
| | | | - Alexander A. Mongin
- Center of Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York, United States of America
- * E-mail:
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Burnstock G. Purinergic signalling and disorders of the central nervous system. Nat Rev Drug Discov 2008; 7:575-90. [PMID: 18591979 DOI: 10.1038/nrd2605] [Citation(s) in RCA: 446] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Purines have key roles in neurotransmission and neuromodulation, with their effects being mediated by the purine and pyrimidine receptor subfamilies, P1, P2X and P2Y. Recently, purinergic mechanisms and specific receptor subtypes have been shown to be involved in various pathological conditions including brain trauma and ischaemia, neurodegenerative diseases involving neuroimmune and neuroinflammatory reactions, as well as in neuropsychiatric diseases, including depression and schizophrenia. This article reviews the role of purinergic signalling in CNS disorders, highlighting specific purinergic receptor subtypes, most notably A(2A), P2X(4) and P2X(7), that might be therapeutically targeted for the treatment of these conditions.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, UK.
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Franco R, Panayiotidis MI, de la Paz LDO. Autocrine signaling involved in cell volume regulation: the role of released transmitters and plasma membrane receptors. J Cell Physiol 2008; 216:14-28. [PMID: 18300263 DOI: 10.1002/jcp.21406] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cell volume regulation is a basic homeostatic mechanism transcendental for the normal physiology and function of cells. It is mediated principally by the activation of osmolyte transport pathways that result in net changes in solute concentration that counteract cell volume challenges in its constancy. This process has been described to be regulated by a complex assortment of intracellular signal transduction cascades. Recently, several studies have demonstrated that alterations in cell volume induce the release of a wide variety of transmitters including hormones, ATP and neurotransmitters, which have been proposed to act as extracellular signals that regulate the activation of cell volume regulatory mechanisms. In addition, changes in cell volume have also been reported to activate plasma membrane receptors (including tyrosine kinase receptors, G-protein coupled receptors and integrins) that have been demonstrated to participate in the regulatory process of cell volume. In this review, we summarize recent studies about the role of changes in cell volume in the regulation of transmitter release as well as in the activation of plasma membrane receptors and their further implications in the regulation of the signaling machinery that regulates the activation of osmolyte flux pathways. We propose that the autocrine regulation of Ca2+-dependent and tyrosine phosphorylation-dependent signaling pathways by the activation of plasma membrane receptors and swelling-induced transmitter release is necessary for the activation/regulation of osmolyte efflux pathways and cell volume recovery. Furthermore, we emphasize the importance of studying these extrinsic signals because of their significance in the understanding of the physiology of cell volume regulation and its role in cell biology in vivo, where the constraint of the extracellular space might enhance the autocrine or even paracrine signaling induced by these released transmitters.
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Affiliation(s)
- Rodrigo Franco
- Laboratory of Cell Biology and Signal Transduction, Biomedical Research Unit, FES-Iztacala, UNAM, Mexico.
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Fisher SK, Cheema TA, Foster DJ, Heacock AM. Volume-dependent osmolyte efflux from neural tissues: regulation by G-protein-coupled receptors. J Neurochem 2008; 106:1998-2014. [PMID: 18518929 DOI: 10.1111/j.1471-4159.2008.05510.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The CNS is particularly vulnerable to reductions in plasma osmolarity, such as occur during hyponatremia, the most commonly encountered electrolyte disorder in clinical practice. In response to a lowered plasma osmolarity, neural cells initially swell but then are able to restore their original volume through the release of osmolytes, both inorganic and organic, and the exit of osmotically obligated water. Given the importance of the maintenance of cell volume within the CNS, mechanisms underlying the release of osmolytes assume major significance. In this context, we review recent evidence obtained from our laboratory and others that indicates that the activation of specific G-protein-coupled receptors can markedly enhance the volume-dependent release of osmolytes from neural cells. Of particular significance is the observation that receptor activation significantly lowers the osmotic threshold at which osmolyte release occurs, thereby facilitating the ability of the cells to respond to small, more physiologically relevant, reductions in osmolarity. The mechanisms underlying G-protein-coupled receptor-mediated osmolyte release and the possibility that this efflux can result in both physiologically beneficial and potentially harmful pathophysiological consequences are discussed.
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Affiliation(s)
- Stephen K Fisher
- Molecular and Behavioral Neuroscience Institute; and Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109-2200, USA.
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