Read by QxMD icon Read


Diana Campos-Beltrán, Åsa Konradsson-Geuken, Jorge E Quintero, Lisa Marshall
D-serine is the major D-amino acid in the mammalian central nervous system. As the dominant co-agonist of the endogenous synaptic NMDA receptor, D-serine plays a role in synaptic plasticity, learning, and memory. Alterations in D-serine are linked to neuropsychiatric disorders including schizophrenia. Thus, it is of increasing interest to monitor the concentration of D-serine in vivo as a relevant player in dynamic neuron-glia network activity. Here we present a procedure for amperometric detection of D-serine with self-referencing ceramic-based microelectrode arrays (MEAs) coated with D-amino acid oxidase from the yeast Rhodotorula gracilis (RgDAAO)...
March 6, 2018: Biosensors
Nazanin R Kondori, Praveen Paul, Jacqueline P Robbins, Ke Liu, John C W Hildyard, Dominic J Wells, Jacqueline S de Belleroche
We have investigated a pathogenic mutation in D-amino acid oxidase (DAO), DAOR199W , associated with familial Amyotrophic Lateral Sclerosis (ALS) that impairs D-serine metabolism and causes protein aggregation, autophagy and cell death in motor neuron cell lines. These features are consistent with the pathogenic processes occurring in ALS but most importantly, we have demonstrated that activation of the formation of ubiquitinated protein inclusions, increased autophagosome production and apoptotic cell death caused by the mutation in cell lines are attenuated by 5,7-dichlorokynurenic acid (DCKA), a selective inhibitor of the glycine/D-serine binding site of the NMDA receptor...
2018: Frontiers in Molecular Biosciences
Kylie B O'Brien, Anjail Z Sharrief, Eric J Nordstrom, Anthony J Travanty, Mailee Huynh, Megan P Romero, Katie C Bittner, Michael T Bowser, Frank H Burton
Tics and compulsions in comorbid Tourette's syndrome (TS) and obsessive-compulsive disorder (OCD) are associated with chronic hyperactivity of parallel cortico/amygdalo-striato-thalamo-cortical (CSTC) loop circuits. Comorbid TS- & OCD-like behaviors have likewise been observed in D1CT-7 mice, in which an artificial neuropotentiating transgene encoding the cAMP-elevating intracellular subunit of cholera toxin (CT) is chronically expressed selectively in somatosensory cortical & amygdalar dopamine (DA) D1 receptor-expressing neurons that activate cortico/amygdalo-striatal glutamate (GLU) output...
February 23, 2018: Journal of Chemical Neuroanatomy
Bence Szilágyi, Péter Kovács, György G Ferenczy, Anita Rácz, Krisztina Németh, Júlia Visy, Pál Szabó, Janez Ilas, György T Balogh, Katalin Monostory, István Vincze, Tamás Tábi, Éva Szökő, György M Keserű
d-Amino acid oxidase (DAAO) is a potential target in the treatment of schizophrenia as its inhibition increases brain d-serine level and thus contributes to NMDA receptor activation. Inhibitors of DAAO were sought testing [6+5] type heterocycles and identified isatin derivatives as micromolar DAAO inhibitors. A pharmacophore and structure-activity relationship analysis of isatins and reported DAAO inhibitors led us to investigate 1H-indazol-3-ol derivatives and nanomolar inhibitors were identified. The series was further characterized by pKa and isothermal titration calorimetry measurements...
February 8, 2018: Bioorganic & Medicinal Chemistry
Gerson D Guercio, Rogerio Panizzutti
After 25 years of its discovery in the rat brain, d-serine is a recognized modulator of synaptic plasticity and cognitive processes through its actions on the NMDA-glutamate receptor. Importantly, cognitive impairment is a core feature of conditions, such as schizophrenia, Alzheimer's disease, depression, and aging, and is associated to disturbances in NMDA-glutamate receptors. The d-serine pathway has been associated with cognitive deficits and these conditions, and, for this reason, d-serine signaling is subject of intense research to probe its role in aiding diagnosis and therapy...
2018: Frontiers in Psychiatry
Loredano Pollegioni, Luciano Piubelli, Gianluca Molla, Elena Rosini
pLG72 is a small, primate-specific protein of 153 amino acids. It is the product of the G72 gene, expressed in testis, spinal cord, and brain. The presence of G72 transcript and pLG72 has recurrently been called into question, however G72 mRNA and pLG72 protein levels were higher in blood and brain of patients with schizophrenia than in healthy controls. On the one hand, the SNP rs2391191 corresponding to the R30K substitution in pLG72 was genetically linked to schizophrenia, reduced thickness of the brain cortex in schizophrenia-affected individuals, and altered memory function...
2018: Frontiers in Molecular Biosciences
Joseph T Coyle, Darrick T Balu
The N-methyl-d-aspartate receptor (NMDAR) is unique in requiring two agonists to bind simultaneously to open its cation channel: the neurotransmitter, glutamate, and the coagonists, glycine, or d-serine. The Snyder laboratory was the first to clone serine racemase (SR), the enzyme that synthesizes d-serine, and to localize it immunocytochemically. Our laboratory has focused on the role of d-serine in brain disorders. Silencing the expression of SR, a risk gene for schizophrenia (SCZ), in mice (SR-/-), results in a phenotype that closely resembles SCZ including: cortical atrophy, reduced dendritic spine density and complexity, downregulation of parvalbumin-positive cortical GABAergic neurons, and cognitive impairments...
2018: Advances in Pharmacology
Herman Wolosker
d-Serine is a physiological coagonist of NMDA receptors involved in synaptic plasticity, neurodevelopment, and neurodegeneration. d-Serine is synthesized by the enzyme serine racemase, which converts l- to d-serine. Recent studies indicate that the supply of l-serine by astroglia fuels the neuronal synthesis of d-serine. This pathway, named the serine shuttle, highlights the importance of the glia-neuron metabolic crosstalk for regulating NMDA receptor activity. Dysfunction of different components of the serine shuttle pathway leads to neurodevelopmental defects, neurodegeneration, and may be involved in psychiatric diseases...
2018: Advances in Pharmacology
Francesco Marchesani, Stefano Bruno, Gianluca Paredi, Samanta Raboni, Barbara Campanini, Andrea Mozzarelli
Serine racemase is a pyridoxal 5'‑phosphate dependent enzyme responsible for the synthesis of d‑serine, a neuromodulator of the NMDA receptors. Its activity is modulated by several ligands, including ATP, divalent cations and protein interactors. The murine orthologue is inhibited by S-nitrosylation at Cys113, a residue adjacent to the ATP binding site. We found that the time course of inhibition of human serine racemase by S-nitrosylation is markedly biphasic, with a fast phase associated with the reaction of Cys113...
January 30, 2018: Biochimica et Biophysica Acta
Ana Covelo, Alfonso Araque
Accumulating evidence indicates that astrocytes are actively involved in brain function by regulating synaptic activity and plasticity. Different gliotransmitters, such as glutamate, ATP, GABA or D-serine, released form astrocytes have been shown to induce different forms of synaptic regulation. However, whether a single astrocyte may release different gliotransmitters is unknown. Here we show that mouse hippocampal astrocytes activated by endogenous (neuron-released endocannabinoids or GABA) or exogenous (single astrocyte Ca2+ uncaging) stimuli modulate putative single CA3-CA1 hippocampal synapses...
January 30, 2018: ELife
Arne Schousboe
Neurotransmission mediated by the two amino acids glutamate and GABA is based on recycling of the two signaling molecules between the presynaptic nerve endings and the surrounding astrocytes. During the recycling process, a fraction of the transmitter pool is lost since both transmitters undergo oxidative metabolism. This loss must be replenished by de novo synthesis which involves the action of pyruvate carboxylase, aminotransferases, glutamate dehydrogenase and glutamine synthetase. Among these enzymes, pyruvate carboxylase and glutamine synthetase are selectively expressed in astrocytes and thus these cells are obligatory partners in synaptic replenishment of both glutamate and GABA...
January 25, 2018: Neuroscience Letters
Hua Tao, Xu Zhou, Qian Xie, Zhonghua Ma, Fuhai Sun, Lili Cui, Yujie Cai, Guoda Ma, Jiawu Fu, Zhou Liu, You Li, Haihong Zhou, Jianghao Zhao, Yanyan Chen, Hui Mai, Ying Chen, Jun Chen, Wei Qi, Chaowen Sun, Bin Zhao, Keshen Li
D-serine is a predominant N-methyl-D-aspartate receptor co-agonist with glutamate, and excessive activation of the receptor plays a substantial role in epileptic seizures. Serine racemase (SRR) is responsible for transforming L-serine to D-serine. In this study, we aimed to investigate the genetic roles of SRR and a neighbouring gene, nonsense-mediated mRNA decay factor (SMG6), in temporal lobe epilepsy (TLE). Here, a total of 496 TLE patients and 528 healthy individuals were successfully genotyped for three SRR tag single nucleotide polymorphisms...
January 24, 2018: Journal of Cellular and Molecular Medicine
Rafael Coveñas, Arturo Mangas, Manuel Lisardo Sànchez, Diana Cadena, Marianne Husson, Michel Geffard
This review updates the findings about the anatomical distribution (using immunohistochemical techniques) and possible functions of D-glutamate in the central nervous system of mammals, as well as compares the distribution of D-glutamate with the distribution of the most studied D-amino acids: D-serine and D-aspartate. The protocol used to obtain highly specific antisera directed against D-amino acids is also reported. Immunoreactivity for D-glutamate was found in dendrites and cell bodies, but not in nerve fibers...
January 24, 2018: Folia Histochemica et Cytobiologica
Kazunari Yoneda, Haruhiko Sakuraba, Tomohiro Araki, Toshihisa Ohshima
A gene encoding L-serine dehydrogenase (L-SerDH) that exhibits extremely low sequence identity to the Agrobacterium tumefaciens L-SerDH was identified in the hyperthermophilic archaeon Pyrobaculum calidifontis. The predicted amino acid sequence showed 36% identity with that of Pseudomonas aeruginosa L-SerDH, suggesting that P. calidifontis L-SerDH is a novel type of L-SerDH, like Ps. aeruginosa L-SerDH. The overexpressed enzyme appears to be the most thermostable L-SerDH described to date, and no loss of activity was observed by incubation for 30 min at temperatures up to 100 °C...
January 20, 2018: Extremophiles: Life Under Extreme Conditions
Saurav Seshadri, Andreas Klaus, Daniel E Winkowski, Patrick O Kanold, Dietmar Plenz
Disturbed activity patterns in cortical networks contribute to the pathophysiology of schizophrenia (SZ). Several lines of evidence implicate NMDA receptor hypofunction in SZ, and blocking NMDA receptor signaling during early neurodevelopment produces cognitive deficits in rodent models that resemble those seen in schizophrenic patients. However, the altered network dynamics underlying these cognitive impairments largely remain to be characterized, especially at the cellular level. Here, we use in vivo two-photon calcium imaging to describe pathological dynamics, occurring in parallel with cognitive dysfunction, in a developmental NMDA receptor hypofunction model...
January 10, 2018: Translational Psychiatry
Suyan Li, Yota Uno, Uwe Rudolph, Johanna Cobb, Jing Liu, Thea Anderson, Deborah Levy, Darrick T Balu, Joseph T Coyle
D-Serine is a co-agonist at forebrain N-methyl-D-aspartate receptors (NMDAR) and is synthesized by serine racemase (SR). Although D-serine and SR were originally reported to be localized to glia, recent studies have provided compelling evidence that under healthy physiologic conditions both are localized primarily in neurons. However, in pathologic conditions, reactive astrocytes can also express SR and synthesize D-serine. Since cultured astrocytes exhibit features of reactive astrocytes, we have characterized D-serine synthesis and the expression of enzymes involved in its disposition in primary glial cultures...
January 3, 2018: Biochemical Pharmacology
Hironori Ozaki, Ran Inoue, Takako Matsushima, Masakiyo Sasahara, Atsushi Hayashi, Hisashi Mori
Diabetic retinopathy (DR) is a leading cause of blindness. DR is recognized as a microvascular disease and inner retinal neurodegeneration. In the course of retinal neurodegeneration, N-methyl-D-aspartate receptor (NMDAR)-mediated excitotoxicity is involved. Full activation of NMDAR requires binding of agonist glutamate and coagonist glycine or D-serine. D-Serine is produced from L-serine by serine racemase (SRR) and contributes to retinal neurodegeneration in rodent models of DR. However, the involvement of SRR in both neurodegeneration and microvascular damage in DR remains unclear...
2018: PloS One
Todd A Fiacco, Ken D McCarthy
A major controversy persists within the field of glial biology concerning whether or not, under physiological conditions, neuronal activity leads to Ca2+-dependent release of neurotransmitters from astrocytes, a phenomenon known as gliotransmission. Our perspective is that, while we and others can apply techniques to cause gliotransmission, there is considerable evidence gathered using astrocyte-specific and more physiological approaches which suggests that gliotransmission is a pharmacological phenomenon rather than a physiological process...
January 3, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Robert S Phillips, Samuel C Ting, Ange G Tetsadjio, Kaitlin L Anderson, Kyle M Friez, Katherine A Miller, Timothy R Hoover
Salmonella enterica serovar Typhimurium utilizes a wide range of growth substrates, some of which are relatively novel. One of these unusual substrates is d-glucosaminate, which is metabolized by the enzymes encoded in the dga operon. d-Glucosaminate is transported and converted to d-glucosaminate-6-phosphate (G6P) by a phosphotransferase system, composed of DgaABCD. The protein product of dgaE, d-glucosaminate-6-phosphate ammonia lyase (DGL), converts G6P to 2-keto-3-deoxygluconate-6-phosphate, which undergoes a retroaldol reaction catalyzed by the DgaF protein to give d-glyceraldehyde-3-phosphate and pyruvate...
December 22, 2017: Biochimica et Biophysica Acta
Satoyuki Takahara, Kiyomi Nakagawa, Tsugumi Uchiyama, Tomoyuki Yoshida, Kazunori Matsumoto, Yasuo Kawasumi, Mineyuki Mizuguchi, Takayuki Obita, Yurie Watanabe, Daichi Hayakawa, Hiroaki Gouda, Hisashi Mori, Naoki Toyooka
Most of the endogenous free d-serine (about 90%) in the brain is produced by serine racemase (SR). d-Serine in the brain is involved in neurodegenerative disorders and epileptic states as an endogenous co-agonist of the NMDA-type glutamate receptor. Thus, SR inhibitors are expected to be novel therapeutic candidates for the treatment of these disorders. In this study, we solved the crystal structure of wild-type SR, and tried to identify a new inhibitor of SR by in silico screening using the structural information...
December 13, 2017: Bioorganic & Medicinal Chemistry Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"