bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delayed treatment with cannabidiol has a cerebroprotective action via a cannabinoid receptor‐independent myeloperoxidase‐inhibiting mechanism
Authors: Hayakawa Kazuhide , Mishima Kenichi , Nozako Masanori , Hazekawa Mai , Irie Keiichi , Fujioka Masayuki , Orito Kensuke , Abe Kohji , Hasebe Nobuyoshi , Egashira Nobuaki , Iwasaki Katsunori , Fujiwara Michihiro 
Published: May 2007

AbstractWe examined the neuroprotective mechanism of cannabidiol, non‐psychoactive component of marijuana, on the infarction in a 4 h mouse middle cerebral artery (MCA) occlusion model in comparison with Δ9‐tetrahydrocannabinol (Δ9‐THC). Release of glutamate in the cortex was measured at 2 h after MCA occlusion. Myeloperoxidase (MPO) and cerebral blood flow were measured at 1 h after reperfusion. In addition, infarct size and MPO were determined at 24 and 72 h after MCA occlusion. The neuroprotective effect of cannabidiol was not inhibited by either SR141716 or AM630. Both pre‐ and post‐ischemic treatment with cannabidiol resulted in potent and long‐lasting neuroprotection, whereas only pre‐ischemic treatment with Δ9‐THC reduced the infarction. Unlike Δ9‐THC, cannabidiol did not affect the excess release of glutamate in the cortex after occlusion. Cannabidiol suppressed the decrease in cerebral blood flow by the failure of cerebral microcirculation after reperfusion and inhibited MPO activity in neutrophils. Furthermore, the number of MPO‐immunopositive cells was reduced in the ipsilateral hemisphere in cannabidiol‐treated group. Cannbidiol provides potent and long‐lasting neuroprotection through an anti‐inflammatory CB1 receptor‐independent mechanism, suggesting that cannabidiol will have a palliative action and open new therapeutic possibilities for treating cerebrovascular disorders.
Genomic and proteomic microglial profiling: pathways for neuroprotective inflammatory responses following nerve fragment clearance and activation
Authors: Glanzer Jason G. , Enose Yoshimi , Wang Tong , Kadiu Irena , Gong Nan , Rozek Wojciech , Liu Jianuo , Schlautman Joshua D. , Ciborowski Pawel S. , Thomas Mark P. , Gendelman Howard E. 
Published: May 2007

AbstractMicroglia, a primary immune effector cell of the central nervous system (CNS) affects homeostatic, neuroprotective, regenerative and degenerative outcomes in health and disease. Despite these broad neuroimmune activities linked to specific environmental cues, a precise cellular genetic profile for microglia in the context of disease and repair has not been elucidated. To this end we used nucleic acid microarrays, proteomics, immunochemical and histochemical tests to profile microglia in neuroprotective immune responses. Optic and sciatic nerve (ON and SN) fragments were used to stimulate microglia in order to reflect immune consequences of nervous system injury. Lipopolysaccharide and latex beads‐induced microglial activation served as positive controls. Cytosolic and secreted proteins were profiled by surface enhanced laser desorption ionization‐time of flight (SELDI‐TOF) ProteinChip®, 1D and 2D difference gel electrophoresis. Proteins were identified by peptide sequencing with tandem mass spectrometry, ELISA and western blot tests. Temporal expression of pro‐inflammatory cytokines, antioxidants, neurotrophins, and lysosomal enzyme expression provided, for the first time, a unique profile of secreted microglia proteins with neuroregulatory functions. Most importantly, this molecular and biochemical signature supports a broad range of microglial functions for debris clearance and promotion of neural repair after injury.
Lysophosphatidylcholine potentiates Ca2+ influx, pore formation and p44/42 MAP kinase phosphorylation mediated by P2X7 receptor activation in mouse microglial cells
Authors: Takenouchi Takato , Sato Mitsuru , Kitani Hiroshi 
Published: May 2007

AbstractThe P2X7 receptor (P2X7R) is an ATP‐gated ion channel highly expressed in microglia. P2X7R plays important roles in inflammatory responses in the brain. However, little is known about the mechanisms regulating its functions in microglia. Lysophosphatidylcholine (LPC), an inflammatory phospholipid that promotes microglial activation, may have some relevance to P2X7R signaling in terms of microglial function. In this study, we examined its effects on P2X7R signaling in a mouse microglial cell line (MG6) and primary microglia. LPC facilitated the sustained increase in the intracellular Ca2+ concentration ([Ca2+]i) through P2X7R channels activated by ATP or BzATP. The potentiated increase in [Ca2+]i was actually inhibited by P2X7R antagonists, brilliant blue G and oxidized ATP. The potentiating effect of LPC was not observed with P2Y receptor systems, which are also expressed in MG6 cells. G2A, a receptor for LPC, was expressed in MG6 cells, but not involved in the facilitating effect of LPC on the P2X7R‐mediated change in [Ca2+]i. Furthermore, LPC enhanced the P2X7R‐associated formation of membrane pores and the activation of p44/42 mitogen‐activated protein kinase. These results suggest that LPC may regulate microglial functions in the brain by enhancing the sensitivity of P2X7R.
Presenilin dependence of phospholipase C and protein kinase C signaling
Authors: Dehvari Nodi , Cedazo‐Minguez Angel , Isacsson Ola , Nilsson Tatjana , Winblad Bengt , Karlström Helena , Benedikz Eirikur , Cowburn Richard F. 
Published: May 2007

AbstractPresenilins (PSs) are involved in processing several proteins such as the amyloid precursor protein (APP), as well as in pathways for cell death and survival. We previously showed that some familial Alzheimer’s disease PS mutations cause increased basal and acetylcholine muscarinic receptor‐stimulated phospholipase C (PLC) activity which was γ‐secretase dependent. To further evaluate the dependence of PLC on PSs we measured PLC activity and the activation of variant protein kinase C (PKC) isoforms in mouse embryonic fibroblasts (MEFs) lacking either PS1, PS2, or both. PLC activity and PKCα and PKCγ activations were significantly lower in PS1 and PS2 double knockout MEFs after PLC stimulation. Protein levels of PKCα and PKCγ were lower in PS1 and PS2 double knockout MEFs. In contrast, PKCδ levels were significantly elevated in PS1 and PS2 double knockout as well as in PS1 knockout MEFs. Also, PKCδ levels were lowered after transfection of PS1 into PS1 knockout or PS double knockout MEFs. Using APP knockout MEFs we showed that the expression of PKCα, but not the other PKC isoforms is partially dependent on APP and can be regulated by APP intracellular domain (AICD). These results show that PLC and PKC activations are modulated by PS and also that PSs differentially regulate the expression of PKC isoforms by both APP/AICD‐dependent and independent mechanisms.
A Critical role for Bim in retinal ganglion cell death
Authors: McKernan Declan P. , Cotter T. G. 
Published: May 2007

AbstractOptic nerve transection results in the death of retinal ganglion cells (RGCs) by apoptosis. Apoptosis is regulated by the Bcl‐2 family of proteins, of which the Bcl‐2 homology (BH3) ‐only proteins forms a subset. As BH3‐only proteins have been shown to play a significant role in regulating cell death in the central nervous system, we wished to investigate the role of Bcl‐2 interacting mediator of cell death (Bim), a prominent member of this protein family in the regulation of cell death in the RGC layer using in vitro retinal explants. In this study, we use an innovative retinal shaving procedure to isolate the cells of the ganglion cell layer to use for western blotting. Members of the BH3‐only protein family are down‐regulated during retinal development and are not normally expressed in the adult retina. Using this procedure, we demonstrate that Bim is re‐expressed and its expression is increased over time following axotomy. Expression of Bad and Bik decreases over the same time course, whereas there is no indication that Bid and Puma are re‐expressed. We show that explants from Bim knockout mice are resistant to axotomy‐induced death when compared with their wild‐type counterparts. Genetic deletion of Bim also prevents caspase 3 cleavage. The activity of Bim can be negatively regulated by phosphorylation. We show that the decrease of Bim phosphorylation correlates with a decrease in expression of survival kinases such as pAkt and pERK over the same time course. These results implicate Bim re‐expression as being essential for axotomy‐induced death of RGCs and that phosphorylation of Bim negatively regulates its activity in RGCs.
Syndapin I and endophilin I bind overlapping proline‐rich regions of dynamin I: role in synaptic vesicle endocytosis
Authors: Anggono Victor , Robinson Phillip J. 
Published: May 2007

AbstractDynamin I mediates vesicle fission during synaptic vesicle endocytosis (SVE). Its proline‐rich domain (PRD) binds the Src‐homology 3 (SH3) domain of a subset of proteins that can deform membranes. Syndapin I, amphiphysin I, and endophilin I are its major partners implicated in SVE. Syndapin binding is controlled by phosphorylation at Ser‐774 and Ser‐778 in the dynamin phospho‐box. We now define syndapin and endophilin‐binding sites by peptide competition and site‐directed mutagenesis. Both bound the same region of the dynamin PRD and both exhibited unusual bidirectional binding modes around core PxxP motifs, unlike amphiphysin which employed a class II binding mode. Endophilin binds to tandem PxxP motifs in the sequence 778SPTPQRRAPAVPPARPGSR796 in dynamin, with SPTPQ being an overhang sequence. In contrast, syndapin binding involves two components in the region 772RRSPTSSPTPQRRAPAVPPARPGSR796. It required a single PxxP core and a non‐PxxP N‐terminally anchored extension which bridges the phospho‐box and may contribute to binding specificity and affinity. Syndapin binding is exquisitely sensitive to the introduction of negative charges almost anywhere along this region, explaining why it is a highly tuned phospho‐sensor. Over‐expression of dynamin point mutants that fail to bind syndapin or endophilin inhibit SVE in cultured neurons. Due to overlapping binding sites the interactions between dynamin and syndapin or endophilin were mutually exclusive. Because syndapin acts as a phospho‐sensor, this supports its role in depolarization‐induced SVE at the synapse, which involves dynamin dephosphorylation. We propose syndapin and endophilin function either at different stages during SVE or in mechanistically distinct types of SVE.
Characterization of mature rat oligodendrocytes: a proteomic approach
Authors: Dumont Debora , Noben Jean‐Paul , Moreels Marjan , Vanderlocht Joris , Hellings Niels , Vandenabeele Frank , Lambrichts Ivo , Stinissen Piet , Robben Johan 
Published: May 2007

AbstractOligodendrocytes are glial cells responsible for the synthesis and maintenance of myelin in the central nervous system (CNS). Oligodendrocytes are vulnerable to damage occurring in a variety of neurological diseases. Understanding oligodendrocyte biology is crucial for the dissemination of de‐ and remyelination mechanisms. The goal of the present study is the construction of a protein database of mature rat oligodendrocytes. Post‐mitotic oligodendrocytes were isolated from mature Wistar rats and subjected to immunocytochemistry. Proteins were extracted and analyzed by means of two‐dimensional gel electrophoresis and two‐dimensional liquid chromatography, both coupled to mass spectrometry. The combination of the gel‐based and gel‐free approach resulted in confident identification of a total of 200 proteins. A minority of proteins were identified in both proteomic strategies. The identified proteins represent a variety of functional groups, including novel oligodendrocyte proteins. The results of this study emphasize the power of the applied proteomic strategy to study known or to reveal new proteins and to investigate their regulation in oligodendrocytes in different disease models.
The lack of CB1 receptors prevents neuroadapatations of both NMDA and GABAA receptors after chronic ethanol exposure
Authors: Warnault Vincent , Houchi Hakim , Barbier Estelle , Pierrefiche Olivier , Vilpoux Catherine , Ledent Catherine , Daoust Martine , Naassila Mickaël 
Published: May 2007

AbstractAs the contribution of cannabinoid (CB1) receptors in the neuroadaptations following chronic alcohol exposure is unknown, we investigated the neuroadaptations induced by chronic alcohol exposure on both NMDA and GABAA receptors in CB1−/− mice. Our results show that basal levels of hippocampal [3H]MK‐801 ((1)‐5‐methyl‐10,11‐dihydro‐5Hdibenzo[a,d]cyclohepten‐5,10‐imine) binding sites were decreased in CB1−/− mice and that these mice were also less sensitive to the locomotor effects of MK‐801. Basal level of both hippocampal and cerebellar [3H]muscimol binding was lower and sensitivity to the hypothermic effects of diazepam and pentobarbital was increased in CB1−/− mice. GABAAα1, β2, and γ2 and NMDA receptor (NR) 1 and 2B subunit mRNA levels were altered in striatum of CB1−/− mice. Our results also showed that [3H]MK‐801 binding sites were increased in cerebral cortex and hippocampus after chronic ethanol ingestion only in wild‐type mice. Chronic ethanol ingestion did not modify the sensitivity to the locomotor effects of MK‐801 in both genotypes. Similarly, chronic ethanol ingestion reduced the number of [3H]muscimol binding sites in cerebral cortex, but not in cerebellum, only in CB1+/+ mice. We conclude that lifelong deletion of CB1 receptors impairs neuroadaptations of both NMDA and GABAA receptors after chronic ethanol exposure and that the endocannabinoid/CB1 receptor system is involved in alcohol dependence.
Mechanisms of axon guidance: membrane dynamics and axonal transport in semaphorin signalling
Authors: Mann Fanny , Rougon Geneviève 
Published: May 2007

AbstractThe intricate geometry of neuronal networks poses many unique cell‐biological problems regarding the way a growing axon responds to its environment. Several groups of ligand–receptor pairs have been identified to regulate such processes. In this study, we take class 3 semaphorins as an example and review what is known about the intracellular movements of semaphorins throughout neuronal cells, transport support structures and location of release sites. We discuss how their receptor trafficking may contribute to regulate membrane dynamics underlying growth cone motility and the physiological contribution made by class 3 semaphorins‐induced acceleration of axoplasmic transport on neurite development.
An oligodendrocyte enhancer in a phylogenetically conserved intron region of the mammalian myelin gene Opalin
Authors: Aruga Jun , Yoshikawa Fumio , Nozaki Yayoi , Sakaki Yoshiyuki , Toyoda Atsushi , Furuichi Teiichi 
Published: May 2007

AbstractOpalin is a transmembrane protein detected specifically in mammalian oligodendrocytes. Opalin homologs are found only in mammals and not in the genome sequences of other animal classes. We first determined the nucleotide sequences of Opalin orthologs and their flanking regions derived from four prosimians, a group of primitive primates. A global comparison revealed that an evolutionarily conserved region exists in the first intron of Opalin. When the conserved domain was assayed for its enhancer activity in transgenic mice, oligodendrocyte‐directed expression was observed. In an oligodendroglial cell line, Oli‐neu, the conserved domain showed oligodendrocyte‐directed expression. The conserved domain is composed of eight subdomains, some of which contain binding sites for Myt1 and cAMP‐response element binding protein (CREB). Deletion analysis and cotransfection experiments revealed that the subdomains have critical roles in Opalin gene expression. Over‐expression of Myt1, treatment of the cell with leukemia inhibitory factor (LIF), and cAMP analog (CREB activator) enhanced the expression of endogenous Opalin in Oli‐neu cells and activated the oligodendrocyte enhancer. These results suggest that LIF, cAMP signaling cascades and Myt1 play significant roles in the differentiation of oligodendrocytes through their action on the Opalin oligodendrocyte enhancer.
EAAT4 phosphorylation at the SGK1 consensus site is required for transport modulation by the kinase
Authors: Rajamanickam Jeyaganesh , Palmada Monica , Lang Florian , Boehmer Christoph 
Published: May 2007

AbstractEAAT4 (SLC1A6) is a Purkinje‐Cell‐specific post‐synaptic excitatory amino acid transporter that plays a major role in clearing synaptic glutamate. EAAT4 abundance and function is known to be modulated by the serum and glucocorticoid inducible kinase (SGK) 1 but the precise mechanism of kinase action has not been defined yet. The present work aims to identify the molecular mechanism of EAAT4 modulation by the kinase. The EAAT4 sequence bears two putative SGK1 consensus sites (at Thr40 and Thr504) at the amino and carboxy terminus that are conserved among species. Expression studies in Xenopus oocytes demonstrated that EAAT4‐mediated [3H] glutamate uptake and cell surface abundance are enhanced by co‐expression of SGK1. Disruption of the SGK1 phosphorylation site at threonine 40 (T40AEAAT4) or of both phosphorylation sites (T40AT504AEAAT4) abrogated the effect of SGK1 on transporter function and expression. SGK1 modulates several transport proteins via inhibition of the ubiquitin ligase Nedd4‐2. Co‐expression of Nedd4‐2 inhibited wild‐type EAAT4 but not the T40AT504AEAAT4 mutant. Besides, RNA interference‐mediated reduction of endogenous Nedd4‐2 (xNedd4‐2) expression increased the activity of the transporter. In conclusion, maximal glutamate transport modulation by SGK1 is accomplished by direct EAAT4 stimulation and to a lesser extent by inhibition of intrinsic Nedd4‐2.
Induction of interleukin‐1β by interleukin‐4 in lipopolysaccharide‐treated mixed glial cultures: microglial‐dependent effects
Authors: Cao Ling , Fei Liang , Chang Tina Ting‐Lan , DeLeo Joyce A. 
Published: May 2007

AbstractGlial‐secreted proinflammatory mediators are dynamically involved in central nervous system responses to exogenous stimuli such as infection, neurotoxins, and nerve injury. The therapeutic use of anti‐inflammatory agents may reduce certain central nervous system pathology induced by inflammatory responses. We investigated the role of interleukin (IL)‐4 in modulating the production of proinflammatory mediators from lipopolysaccharide‐stimulated mixed glia in vitro. Interestingly, IL‐4 significantly enhanced IL‐1β secretion and did not affect monocyte chemoattractant protein‐1 release, even though IL‐4 considerably inhibited IL‐6, tumor necrosis factor α, and nitric oxide production from rat neonatal mixed glia. Further, IL‐4 exhibited inhibitory effects on IL‐1β production in microglial‐enriched cultures, while significantly increasing IL‐1β production in microglial‐depleted glia. The enhancing effect of IL‐4 on IL‐1β production was found to be inversely correlated with the percentage of microglia present in the mixed glial population. In summary, IL‐4 did not act as a global anti‐inflammatory cytokine and in fact, under certain situations enhanced IL‐1β secretion. We conclude that IL‐4 exerts its anti‐inflammatory effects in a limited and target‐specific manner, which is delicately regulated by the cellular microenvironment. Therefore, precaution should be taken when clinically using IL‐4 to treat diseases manifested by overt inflammatory responses.
Species identification of birds through genetic analysis of naturally shed feathers
Authors: RUDNICK JAMIE A. , KATZNER TODD E. , BRAGIN EVGENY A. , DeWOODY J. ANDREW 
Published: May 2007

AbstractGenetic analysis of noninvasively collected bird feathers is of growing importance to avian ecology; however, most genetic studies that utilize feathers make no mention of the need to verify their species of origin. While plumage patterns and collection location often are indicative of species identity, broad‐scale feather collections may require definitive species identification prior to analysis. Genetic species identification has been applied to noninvasively collected samples from a wide range of taxa but, to date, these techniques have not been widely used on bird feathers. Here, we develop and test a polymerase chain reaction (PCR)‐based technique for identifying eastern imperial eagle (Aquila heliaca) samples among a vast number of noninvasively collected feathers. Species identification is accomplished by amplifying a fragment of the mitochondrial cytochrome c oxidase I gene, then digesting that fragment with a restriction enzyme. The resulting species‐specific restriction fragment length polymorphisms (RFLPs) are easily visualized by gel electrophoresis. We tested this PCR‐RFLP assay on over 300 individuals that had been genetically identified from noninvasively collected feathers and demonstrated that the assay is both reliable and robust for DNA of low quality and quantity. The genetic methods of species identification used to develop this assay can readily be applied to other bird assemblages, making them particularly relevant to a broad range of future avian research.
Characterization of polymorphic microsatellites in the logrunner, Orthonyx temminckii (Aves: Orthonychidae)
Authors: NICHOLLS JAMES A. , AUSTIN JEREMY J. , PAVLACKY DAVID C. , GREEN DAVID J. 
Published: May 2007

AbstractWe isolated and characterized 10 polymorphic microsatellite loci in the logrunner (Orthonyx temminckii), a rainforest‐dwelling Australian bird. The number of alleles per locus observed within two populations ranged from three to 39, with observed heterozygosities of between 0.12 and 1.00. We demonstrate that these markers are useful for both population‐ and individual‐level analyses.
Melatonin counteracts the loss of agonist‐evoked contraction of aortic rings induced by incubation
Authors: Lartaud Isabelle , Faure Sébastien , Tabellion Aurore , Resende Angela C. , Nadaud Sophie , Bagrel Denyse , Capdeville‐Atkinson Christine , Atkinson Jeffrey 
Published: May 2007

AbstractIncubation of aortic rings in a culture medium produces phenomena similar to those observed with aging, i.e. oxidative stress and inflammation leading to increased nitric oxide (NO)‐mediated dilation and decreased arterial sensitivity to vasoconstrictor agents. We evaluated whether melatonin protects aortic rings from such a decrease in vasoreactivity. Two concentrations of melatonin were used: 10−8 m, EC50 for vascular MT1–MT2 receptors, and 10−5 m, reported as anti‐oxidant. Anti‐oxidant capacity, inducible nitric oxide synthase (iNOS) expression and isometric contraction of thoracic aorta rings (Wistar rats) evoked by norepinephrine (NE) were assessed. Three days of incubation of aortic rings induced iNOS expression and a fall in NE‐evoked contraction. When melatonin was added to the organ bath, it (10−5 m) increased (+96%, P < 0.05), but did not restore (compared with freshly isolated rings) NE‐evoked contraction. Three days of treatment with melatonin increased (10−8 m, +99%) or restored (10−5 m, +216%) NE‐evoked contraction (compared with freshly isolated rings). The beneficial effects of 10−8 and 10−5 m melatonin on NE‐evoked contraction were abolished in the presence of luzindole (2 × 10−6 m, a melatonin receptor antagonist). The incubation‐induced increase in iNOS expression was reduced following 3 days of melatonin administration (10−8 and 10−5 m). Melatonin (10−5 m) increased catalase activity (6550 ± 256, P < 0.05 vs. nontreated fresh aortic rings 5554 ± 444 nmol min−1 mg protein−1). In conclusion, melatonin counteracts the incubation‐induced loss of agonist‐evoked contraction of aortic rings by a specific receptor‐mediated phenomenon involving iNOS expression; at higher melatonin concentrations, an anti‐oxidant effect is probably also involved.