National Institute of Physiological science
National Institute of Physiological science
Sedzik J.,Institute of Chemical Technology |
Sedzik J.,National Institute of Physiological science |
Sedzik J.,University of Tokyo |
Jastrzebski J.P.,University of Warmia and Mazury |
Ikenaka K.,National Institute of Physiological science
Journal of Neuroscience Research | Year: 2013
The shortest sequence of amino acids in protein containing functional and structural information is a "motif." To understand myelin protein functions, we intensively searched for motifs that can be found in myelin proteins. Some myelin proteins had several different motifs or repetition of the same motif. The most abundant motif found among myelin proteins was a myristoylation motif. Bovine MAG held 11 myristoylation motifs and human myelin basic protein held as many as eight such motifs. PMP22 had the fewest myristoylation motifs, which was only one; rat PMP22 contained no such motifs. Cholesterol recognition/interaction amino-acid consensus (CRAC) motif was not found in myelin basic protein. P2 protein of different species contained only one CRAC motif, except for P2 of horse, which had no such motifs. MAG, MOG, and P0 were very rich in CRAC, three to eight motifs per protein. The analysis of motifs in myelin proteins is expected to provide structural insight and refinement of predicted 3D models for which structures are as yet unknown. Analysis of motifs in mutant proteins associated with neurological diseases uncovered that some motifs disappeared in P0 with mutation found in neurological diseases. There are 2,500 motifs deposited in a databank, but 21 were found in myelin proteins, which is only 1% of the total known motifs. There was great variability in the number of motifs among proteins from different species. The appearance or disappearance of protein motifs after gaining point mutation in the protein related to neurological diseases was very interesting. © 2013 Wiley Periodicals, Inc.
Marumo T.,Taisho Pharmaceutical Co. |
Eto K.,National Institute of Physiological science |
Eto K.,Japan Science and Technology Agency |
Wake H.,National Institute of Physiological science |
And 4 more authors.
British Journal of Pharmacology | Year: 2010
BACKGROUND AND PURPOSE: 20-Hydroxyeicosatetraenoic acid is a potent vasoconstrictor that contributes to cerebral ischaemia. An inhibitor of 20-Hydroxyeicosatetraenoic acid synthesis, TS-011, reduces infarct volume and improves neurological deficits in animal stroke models. However, little is known about how TS-011 affects the microvessels in ischaemic brain. Here, we investigated the effect of TS-011 on microvessels after cerebral ischaemia.EXPERIMENTAL APPROACH: TS-011 (0.3 mg.kg -1) or a vehicle was infused intravenously for 1 h every 6 h in a mouse model of stroke, induced by transient occlusion of the middle cerebral artery occlusion following photothrombosis. The cerebral blood flow velocity and the vascular perfusion area of the peri-infarct microvessels were measured using in vivo two-photon imaging.KEY RESULTS: The cerebral blood flow velocities in the peri-infarct microvessels decreased at 1 and 7 h after reperfusion, followed by an increase at 24 h after reperfusion in the vehicle-treated mice. We found that TS-011 significantly inhibited both the decrease and the increase in the blood flow velocities in the peri-infarct microvessels seen in the vehicle-treated mice after reperfusion. In addition, TS-011 significantly inhibited the reduction in the microvascular perfusion area after reperfusion, compared with the vehicle-treated group. Moreover, TS-011 significantly reduced the infarct volume by 40% at 72 h after middle cerebral artery occlusion.CONCLUSIONS AND IMPLICATIONS: These findings demonstrated that infusion of TS-011 improved defects in the autoregulation of peri-infarct microcirculation and reduced the infarct volume. Our results could be relevant to the treatment of cerebral ischaemia. © 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society.
Takahashi K.,Nagoya University |
Taguchi T.,Nagoya University |
Tanaka S.,National Institute of Physiological Science |
Sadato N.,National Institute of Physiological Science |
And 3 more authors.
Neuroscience Research | Year: 2011
Skin pain and muscle pain are categorically distinct from each other. While skin pain is a sharp, spatially localized sensation, muscle pain is a dull, poorly localized and more unpleasant one. We hypothesized that there are specific brain regions preferentially activated by muscle pain compared to skin pain. To test this hypothesis, brain responses were recorded from 13 normal male subjects in response to repeated painful electrical stimulation of the muscle and skin of the left leg, using 3-T magnetic resonance imaging scanner. The common brain regions that responded to painful stimulations of both skin and muscle were the thalamus, anterior cingulate cortex, bilateral insula, contralateral primary and secondary somatosensory cortices, and ipsilateral cerebellum. Brain regions specifically activated by muscle stimulation were the midbrain, bilateral amygdala, caudate, orbitofrontal cortex, hippocampus, parahippocampus and superior temporal pole, most of which are related to emotion. Regions except the midbrain showed contralateral preference. These results suggest that dull sensation, which is characteristic of muscular pain, is related with processing in these brain regions. © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society.
Nakagawa K.,National Institute of Physiological science |
Otsuru N.,National Institute of Physiological science |
Inui K.,National Institute of Physiological science |
Kakigi R.,National Institute of Physiological science
NeuroImage | Year: 2014
Changes in continuous sounds elicit a preattentive component that peaks at around 100. ms (Change-N1m) on electroencephalograms or magnetoencephalograms (MEG). Change-N1m is thought to reflect brain activity relating to the automatic detection of changes, which facilitate processes for the execution of appropriate behavior in response to new environmental events. The aim of the present MEG study was to elucidate whether a component relating to auditory changes existed earlier than N1m. Change-related cortical responses were evoked by abrupt sound movement in a train of clicks at 100. Hz. Sound movement was created by inserting an interaural time delay (ITD) of 0.15, 0.25, 0.35, and 0.45. ms into the right ear. Ten out of 12 participants exhibited clear change-related cortical responses earlier than Change-N1m at around 60. ms (Change-P50m). The results of source analysis showed that Change-P50m originated from the superior temporal gyrus of both hemispheres and that its location did not differ significantly from dipoles for the response to the sound onset. The magnitude of Change-P50m increased and the peak latency shortened with an increase in the ITD, similar to those of Change-N1m. These results suggest that change-related cortical activity is present as early as its onset latency at around 50. ms. © 2013 Elsevier Inc.
Hoivik E.A.,University of Bergen |
Bjanesoy T.E.,University of Bergen |
Mai O.,Institute for Neural Signal Transduction |
Okamoto S.,National Institute of Physiological science |
And 5 more authors.
Endocrinology | Year: 2011
The nuclear receptor steroidogenic factor 1/adrenal 4 binding protein (SF-1/Ad4BP) is an essential regulator of endocrine development and function, and the expression of the corresponding gene (sf-1/ad4bp) is precisely regulated in a time-and tissue-dependent manner. We previously demonstrated that the basal promoter of sf-1/ad4bp is controlled by DNA methylation and that its methylation status reflects the expression pattern of SF-1/Ad4BP. Recently, three intronic enhancers were identified in the sf-1/ad4bp gene that target SF-1/Ad4BP expression to the fetal adrenal (FAdE; fetal adrenalspecific enhancer), to pituitary gonadotropes (PGE; pituitary gonadotrope-specific enhancer), and to the ventromedial hypothalamic nucleus (VMHE; ventromedial hypothalamic nucleus-specific enhancer). Here, we demonstrate that the activity of these enhancers is correlated with their DNA methylation status. We show that they are hypomethylated in tissues where they are active and generally hypermethylated in tissues where they are not active. Furthermore, we demonstrate in transient transfection experiments that forced DNA methylation represses reporter gene activity driven by these enhancers. These data directly demonstrate a functional significance for the enhancers' methylation status. Intriguingly, further analyses of the basal promoter in gonadotropes revealed that it is methylated in these cells, in contrast to other SF-1/Ad4BP-expressing tissues. Consistent with this, sf-1/ad4bp is transcribed from an alternative promoter in gonadotropes. Taken together, our experiments show that the tissue-specific expression of SF-1/Ad4BP is epigenetically regulated and identify tissue-specific differentially methylated regions within the sf-1/ad4bp locus that are essential for its transcriptional control. Copyright © 2011 by The Endocrine Society.
Wake H.,U.S. National Institutes of Health |
Moorhouse A.J.,University of New South Wales |
Nabekura J.,National Institute of Physiological science |
Nabekura J.,Graduate University for Advanced Studies
Neuron Glia Biology | Year: 2012
Microglia cells are the immune cells of the central nervous system and consequently play important roles in brain infections and inflammation. Recent in vivo imaging studies have revealed that in the resting healthy brain, microglia are highly dynamic, moving constantly to actively survey the brain parenchyma. These active microglia can rapidly respond to pathological insults, becoming activated to induce a range of effects that may contribute to both pathogenesis, or to confer neuronal protection. However, interactions between microglia and neurons are being recognized as important in shaping neural circuit activity under more normal, physiological conditions. During development and neurogenesis, microglia interactions with neurons help to shape the final patterns of neural circuits important for behavior and with implications for diseases. In the mature brain, microglia can respond to changes in sensory activity and can influence neuronal activity acutely and over the long term. Microglia seem to be particularly involved in monitoring the integrity of synaptic function. In this review, we discuss some of these new insights into the involvement of microglia in neural circuits. © 2012 Cambridge University Press. This is a work of the U.S. Government and is not subject to copyright protection in the United States.
Phongphanphanee P.,National Institute of Physiological science |
Phongphanphanee P.,Novartis |
Marino R.A.,Queen's University |
Kaneda K.,National Institute of Physiological science |
And 8 more authors.
European Journal of Neuroscience | Year: 2014
The superior colliculus (SC) is critical in localizing salient visual stimuli and making decisions on the location of the next saccade. Lateral interactions across the spatial map of the SC are hypothesized to help mediate these processes. Here, we investigate lateral interactions within the SC by applying whole-cell recordings in horizontal slices of mouse SC, which maintained the local structure of the superficial (SCs) visual layer, which is hypothesized to participate in localizing salient stimuli, and the intermediate (SCi) layer, which is supposed to participate in saccade decision-making. When effects of either electrical or chemical (uncaging of free glutamate) stimuli were applied to multiple sites with various distances from the recorded cell, a pattern of center excitation-surround inhibition was found to be prominent in SCs. When the interactions of synaptic effects induced by simultaneous stimulation of two sites were tested, non-linear facilitatory or inhibitory interactions were observed. In contrast, in the SCi, stimulation induced mainly excitation, which masked underlying inhibition. The excitatory synaptic effects of stimulation applied at remote sites were summed in a near linear manner. The result suggested that SCs lateral interactions appear suitable for localizing salient stimuli, while the lateral interactions within SCi are more suitable for faithfully accumulating subthreshold signals for saccadic decision-making. © 2014 Federation of European Neuroscience Societies and John Wiley and Sons Ltd.
Nakano K.,University of Tsukuba |
Toya M.,University of Tokyo |
Toya M.,RIKEN |
Yoneda A.,Japan Women's University |
And 8 more authors.
Traffic | Year: 2011
Proper cell morphogenesis requires the co-ordination of cell polarity, cytoskeletal organization and vesicle trafficking. The Schizosaccharomyces pombe mutant pob1-664 has a curious lemon-like shape, the basis of which is not understood. Here, we found abundant vesicle accumulation in these cells, suggesting that Pob1 plays a role in vesicle trafficking. We identified Rho3 as a multicopy suppressor of this phenotype. Because Rho3 function is related to For3, an actin-polymerizing protein, and Sec8, a component of the exocyst complex, we analyzed their functional relationship with Pob1. Pob1 was essential for the formation of actin cables (by interacting with For3) and for the polarized localization of Sec8. Although neither For3 nor Sec8 is essential for polarized growth, their simultaneous disruption prevented tip growth and yielded a lemon-like cell morphology similar to pob1-664. Thus, Pob1 may ensure cylindrical cell shape of S. pombe by coupling actin-mediated vesicle transport and exocyst-mediated vesicle tethering during secretory vesicle targeting. © 2011 John Wiley & Sons A/S.
Numata T.,National Institute of Physiological science |
Numata T.,Kyoto University |
Sato K.,National Institute of Physiological science |
Christmann J.,Max Planck Institute of Molecular Physiology |
And 5 more authors.
Journal of Physiology | Year: 2012
Hypertonicity-induced cation channels (HICCs) are key-players in proliferation and apoptosis but their molecular correlate remains obscure. Furthermore, the activation profile of HICCs is not well defined yet. We report here that, in HeLa cells, intracellular adenosine diphosphate ribose (ADPr) and cyclic ADPr (cADPr), as supposed activators of TRPM2, elicited cation currents that were virtually identical to the osmotic activation of HICCs. Silencing of the expression of TRPM2 and of the ecto-enzyme CD38 (as a likely source of ADPr and cADPr) inhibited HICC as well as nucleotide-induced currents and, in parallel, the hypertonic volume response of cells (the regulatory volume increase, RVI) was attenuated. Quantification of intracellular cADPr levels and the systematic application of extra- vs. intracellular nucleotides indicate that the outwardly directed gradient rather than the cellular activity of ADPr and cADPr triggers TRPM2 activation, probably along with a simultaneous biotransformation of nucleotides. Cloning of TRPM2 identified the ΔC-splice variant as the molecular correlate of the HICC, which could be strongly supported by a direct comparison of the respective Ca 2+ selectivity. Finally, immunoprecipitation and high-resolution FRET/FLIM imaging revealed the interaction of TRPM2 and CD38 in the native as well as in a heterologous (HEK293T) expression system. We propose transport-related nucleotide export via CD38 as a novel mechanism of TRPM2/HICC activation. With the biotransformation of nucleotides running in parallel, continuous zero trans-conditions are achieved which will render the system infinitely sensitive. (Recieved 30 September 2011; accepted after revision 31 December 2011; first published online 4 January 2012) © 2012 The Authors. The Journal of Physiology © 2012 The Physiological Society.
Nakagawa H.,Nagoya City University |
Nakagawa H.,Japan Science and Technology Agency |
Hishikawa K.,Nagoya City University |
Eto K.,National Institute of Physiological science |
And 9 more authors.
ACS Chemical Biology | Year: 2013
Two-photon-excitation release of nitric oxide (NO) from our recently synthesized photolabile NO donor, Flu-DNB, was confirmed to allow fine spatial and temporal control of NO release at the subcellular level in vitro. We then evaluated in vivo applications. Femtosecond near-infrared pulse laser irradiation of predefined regions of interest in living mouse brain treated with Flu-DNB induced NO-release-dependent, transient vasodilation specifically at the irradiated site. Photoirradiation in the absence of Flu-DNB had no effect. Further, NO release from Flu-DNB by pulse laser irradiation was shown to cause chemoattraction of microglial processes to the irradiated area in living mouse brain. To our knowledge, this is the first demonstration of induction of biological responses in vitro and in vivo by means of precisely controlled, two-photon-mediated release of NO. © 2013 American Chemical Society.