51
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Endogenous calcitonin regulates lipid and glucose metabolism in diet-induced obesity mice. Sci Rep 2018; 8:17001. [PMID: 30451912 PMCID: PMC6242993 DOI: 10.1038/s41598-018-35369-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 11/05/2018] [Indexed: 12/22/2022] Open
Abstract
Calcitonin (CT) plays an important role in calcium homeostasis, and its precursor, proCT, is positively associated with the body mass index in the general human population. However, the physiological role of endogenous CT in the regulation of metabolism remains unclear. Knockout mice with gene-targeted deletion of exon 4 of Calca (CT KO) were generated by targeted modification in embryonic stem cells. Male mice were used in all experiments and were fed a slightly higher fat diet than the standard diet. The CT KO mice did not exhibit any abnormal findings in appearance, but exhibited weight loss from 15 months old, i.e., significantly decreased liver, adipose tissue, and kidney weights, compared with wild-type control mice. Furthermore, CT KO mice exhibited significantly decreased fat contents in the liver, lipid droplets in adipose tissues, serum glucose, and lipid levels, and significantly increased insulin sensitivity and serum adiponectin levels. CT significantly promoted 3T3-L1 adipocyte differentiation and suppressed adiponectin release. These results suggested that CT gene deletion prevents obesity, hyperglycemia, and hyperlipidemia in aged male mice. This is the first definitive evidence that CT may contribute to glucose and lipid metabolism in aged male mice, possibly via decreased adiponectin secretion from adipocytes.
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52
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Zhou L, Hossain MI, Yamazaki M, Abe M, Natsume R, Konno K, Kageyama S, Komatsu M, Watanabe M, Sakimura K, Takebayashi H. Deletion of exons encoding carboxypeptidase domain of Nna1 results in Purkinje cell degeneration (pcd
) phenotype. J Neurochem 2018; 147:557-572. [DOI: 10.1111/jnc.14591] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 08/31/2018] [Accepted: 09/03/2018] [Indexed: 02/02/2023]
Affiliation(s)
- Li Zhou
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- Division of Neurobiology and Anatomy; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
| | - M. Ibrahim Hossain
- Division of Neurobiology and Anatomy; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
| | - Manabu Abe
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
| | - Rie Natsume
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
| | - Kohtaro Konno
- Department of Anatomy; Faculty of Medicine; Hokkaido University; Sapporo Japan
| | - Shun Kageyama
- Department of Biochemistry; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
| | - Masaaki Komatsu
- Department of Biochemistry; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
| | - Masahiko Watanabe
- Department of Anatomy; Faculty of Medicine; Hokkaido University; Sapporo Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
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53
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Katano T, Takao K, Abe M, Yamazaki M, Watanabe M, Miyakawa T, Sakimura K, Ito S. Distribution of Caskin1 protein and phenotypic characterization of its knockout mice using a comprehensive behavioral test battery. Mol Brain 2018; 11:63. [PMID: 30359304 PMCID: PMC6202847 DOI: 10.1186/s13041-018-0407-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/14/2018] [Indexed: 01/17/2023] Open
Abstract
Calcium/calmodulin-dependent serine protein kinase (CASK)-interacting protein 1 (Caskin1) is a direct binding partner of the synaptic adaptor protein CASK. Because Caskin1 forms homo-multimers and binds not only CASK but also other neuronal proteins in vitro, it is anticipated to have neural functions; but its exact role in mammals remains unclear. Previously, we showed that the concentration of Caskin1 in the spinal dorsal horn increases under chronic pain. To characterize this protein, we generated Caskin1-knockout (Caskin1-KO) mice and specific anti-Caskin1 antibodies. Biochemical and immunohistochemical analyses demonstrated that Caskin1 was broadly distributed in the whole brain and spinal cord, and that it primarily localized at synapses. To elucidate the neural function of Caskin1 in vivo, we subjected Caskin1-KO mice to comprehensive behavioral analysis. The mutant mice exhibited differences in gait, enhanced nociception, and anxiety-like behavior relative to their wild-type littermates. In addition, the knockouts exhibited strong freezing responses, with or without a cue tone, in contextual and cued-fear conditioning tests as well as low memory retention in the Barnes Maze test. Taken together, these results suggest that Caskin1 contributes to a wide spectrum of behavioral phenotypes, including gait, nociception, memory, and stress response, in broad regions of the central nervous system.
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Affiliation(s)
- Tayo Katano
- Department of Medical Chemistry, Kansai Medical University, Hirakata, 573-1010 Japan
| | - Keizo Takao
- Section of Behavior Patterns, National Institute of Physiological Sciences NINS, Okazaki, Aichi 444-8585 Japan
- Division of Experimental Animal Resource and Development, Life Science Research Center, University of Toyama, Toyama, 930-0194 Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585 Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585 Japan
- Department of Neurology, University of California, San Francisco, 94158 USA
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo, 060-8638 Japan
| | - Tsuyoshi Miyakawa
- Section of Behavior Patterns, National Institute of Physiological Sciences NINS, Okazaki, Aichi 444-8585 Japan
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192 Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585 Japan
| | - Seiji Ito
- Department of Medical Chemistry, Kansai Medical University, Hirakata, 573-1010 Japan
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54
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Deficiency of AMPAR-Palmitoylation Aggravates Seizure Susceptibility. J Neurosci 2018; 38:10220-10235. [PMID: 30355633 DOI: 10.1523/jneurosci.1590-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/13/2018] [Accepted: 10/12/2018] [Indexed: 01/01/2023] Open
Abstract
Synaptic AMPAR expression controls the strength of excitatory synaptic transmission and plasticity. An excess of synaptic AMPARs leads to epilepsy in response to seizure-inducible stimulation. The appropriate regulation of AMPARs plays a crucial role in the maintenance of the excitatory/inhibitory synaptic balance; however, the detailed mechanisms underlying epilepsy remain unclear. Our previous studies have revealed that a key modification of AMPAR trafficking to and from postsynaptic membranes is the reversible, posttranslational S-palmitoylation at the C-termini of receptors. To clarify the role of palmitoylation-dependent regulation of AMPARs in vivo, we generated GluA1 palmitoylation-deficient (Cys811 to Ser substitution) knock-in mice. These mutant male mice showed elevated seizure susceptibility and seizure-induced neuronal activity without impairments in synaptic transmission, gross brain structure, or behavior at the basal level. Disruption of the palmitoylation site was accompanied by upregulated GluA1 phosphorylation at Ser831, but not at Ser845, in the hippocampus and increased GluA1 protein expression in the cortex. Furthermore, GluA1 palmitoylation suppressed excessive spine enlargement above a certain size after LTP. Our findings indicate that an abnormality in GluA1 palmitoylation can lead to hyperexcitability in the cerebrum, which negatively affects the maintenance of network stability, resulting in epileptic seizures.SIGNIFICANCE STATEMENT AMPARs predominantly mediate excitatory synaptic transmission. AMPARs are regulated in a posttranslational, palmitoylation-dependent manner in excitatory synapses of the mammalian brain. Reversible palmitoylation dynamically controls synaptic expression and intracellular trafficking of the receptors. Here, we generated GluA1 palmitoylation-deficient knock-in mice to clarify the role of AMPAR palmitoylation in vivo We showed that an abnormality in GluA1 palmitoylation led to hyperexcitability, resulting in epileptic seizure. This is the first identification of a specific palmitoylated protein critical for the seizure-suppressing process. Our data also provide insight into how predicted receptors such as AMPARs can effectively preserve network stability in the brain. Furthermore, these findings help to define novel key targets for developing anti-epileptic drugs.
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55
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Epistasis between Pax6 Sey and genetic background reinforces the value of defined hybrid mouse models for therapeutic trials. Gene Ther 2018; 25:524-537. [PMID: 30258099 PMCID: PMC6335240 DOI: 10.1038/s41434-018-0043-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/02/2018] [Accepted: 09/05/2018] [Indexed: 12/21/2022]
Abstract
The small eye (Sey) mouse is a model of PAX6-aniridia syndrome (aniridia). Aniridia, a congenital ocular disorder caused by heterozygous loss-of-function mutations in PAX6, needs new vision saving therapies. However, high phenotypic variability in Sey mice makes development of such therapies challenging. We hypothesize that genetic background is a major source of undesirable variability in Sey mice. Here we performed a systematic quantitative examination of anatomical, histological, and molecular phenotypes on the inbred C57BL/6J, hybrid B6129F1, and inbred 129S1/SvImJ backgrounds. The Sey allele significantly reduced eye weight, corneal thickness, PAX6 mRNA and protein levels, and elevated blood glucose levels. Surprisingly, Pax6Sey/Sey brains had significantly elevated Pax6 transcripts compared to Pax6+/+ embryos. Genetic background significantly influenced 12/24 measurements, with inbred strains introducing severe ocular and blood sugar phenotypes not observed in hybrid mice. Additionally, significant interactions (epistasis) between Pax6 genotype and genetic background were detected in measurements of eye weight, cornea epithelial thickness and cell count, retinal mRNA levels, and blood glucose levels. The number of epistatic interactions was reduced in hybrid mice. In conclusion, severe phenotypes in the unnatural inbred strains reinforce the value of more naturalistic F1 hybrid mice for the development of therapies for aniridia and other disorders.
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56
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Xu F, Takahashi H, Tanaka Y, Ichinose S, Niwa S, Wicklund MP, Hirokawa N. KIF1Bβ mutations detected in hereditary neuropathy impair IGF1R transport and axon growth. J Cell Biol 2018; 217:3480-3496. [PMID: 30126838 PMCID: PMC6168269 DOI: 10.1083/jcb.201801085] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 05/31/2018] [Accepted: 07/05/2018] [Indexed: 02/07/2023] Open
Abstract
Uncovering the mechanistic link between kinesin motors and neuropathy, Xu et al. identify functional KIF1Bβ mutations in human hereditary neuropathy to analyze them in mouse models. They propose that KIF1Bβ transports IGF1R and facilitates axonal outgrowth. Both of these effects are significantly affected by the clinical mutations. KIF1Bβ is a kinesin-3 family anterograde motor protein essential for neuronal development, viability, and function. KIF1Bβ mutations have previously been reported in a limited number of pedigrees of Charcot-Marie-Tooth disease type 2A (CMT2A) neuropathy. However, the gene responsible for CMT2A is still controversial, and the mechanism of pathogenesis remains elusive. In this study, we show that the receptor tyrosine kinase IGF1R is a new direct binding partner of KIF1Bβ, and its binding and transport is specifically impaired by the Y1087C mutation of KIF1Bβ, which we detected in hereditary neuropathic patients. The axonal outgrowth and IGF-I signaling of Kif1b−/− neurons were significantly impaired, consistent with decreased surface IGF1R expression. The complementary capacity of KIF1Bβ-Y1087C of these phenotypes was significantly impaired, but the binding capacity to synaptic vesicle precursors was not affected. These data have supported the relevance of KIF1Bβ in IGF1R transport, which may give new clue to the neuropathic pathogenesis.
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Affiliation(s)
- Fang Xu
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hironori Takahashi
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yosuke Tanaka
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Sotaro Ichinose
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shinsuke Niwa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Nobutaka Hirokawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan .,Center of Excellence in Genome Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
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57
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Sadato D, Ono T, Gotoh-Saito S, Kajiwara N, Nomura N, Ukaji M, Yang L, Sakimura K, Tajima Y, Oboki K, Shibasaki F. Eukaryotic translation initiation factor 3 (eIF3) subunit e is essential for embryonic development and cell proliferation. FEBS Open Bio 2018; 8:1188-1201. [PMID: 30087825 PMCID: PMC6070656 DOI: 10.1002/2211-5463.12482] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 04/13/2018] [Accepted: 06/12/2018] [Indexed: 11/06/2022] Open
Abstract
Mammalian eukaryotic translation initiation factor 3 (eIF3) is the largest complex of the translation initiation factors. The eIF3 complex is comprised of thirteen subunits, which are named eIF3a to eIF3 m in most multicellular organisms. The eIF3e gene locus is one of the most frequent integration sites of mouse mammary tumor virus (MMTV), which induces mammary tumors in mice. MMTV-integration events result in the expression of C-terminal-truncated eIF3e proteins, leading to mammary tumor formation. We have shown that tumor formation can be partly caused by activation of hypoxia-inducible factor 2α. To investigate the function of eIF3e in mammals, we generated eIF3e-deficient mice. These eIF3e-/- mice are embryonically lethal, while eIF3e+/- mice are much smaller than wild-type mice. In addition, eIF3e+/- mouse embryonic fibroblasts (MEFs) contained reduced levels of eIF3a and eIF3c subunits and exhibited reduced cellular proliferation. These results suggest that eIF3e is essential for embryonic development in mice and plays a role in maintaining eIF3 integrity.
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Affiliation(s)
- Daichi Sadato
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan.,Department of Applied Biological Science Faculty of Science and Technology Tokyo University of Science Noda Chiba Japan
| | - Tomio Ono
- Center for Basic Technology Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Saki Gotoh-Saito
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Naoki Kajiwara
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Namiko Nomura
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Masako Ukaji
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Liying Yang
- Center for Basic Technology Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology Brain Research Institute Niigata University Japan
| | - Youichi Tajima
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Keisuke Oboki
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
| | - Futoshi Shibasaki
- Department of Molecular Medical Research Tokyo Metropolitan Institute of Medical Science Japan
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58
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Kawabata Galbraith K, Fujishima K, Mizuno H, Lee SJ, Uemura T, Sakimura K, Mishina M, Watanabe N, Kengaku M. MTSS1 Regulation of Actin-Nucleating Formin DAAM1 in Dendritic Filopodia Determines Final Dendritic Configuration of Purkinje Cells. Cell Rep 2018; 24:95-106.e9. [DOI: 10.1016/j.celrep.2018.06.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/01/2018] [Accepted: 06/01/2018] [Indexed: 10/28/2022] Open
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59
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Imai H, Shoji H, Ogata M, Kagawa Y, Owada Y, Miyakawa T, Sakimura K, Terashima T, Katsuyama Y. Dorsal Forebrain-Specific Deficiency of Reelin-Dab1 Signal Causes Behavioral Abnormalities Related to Psychiatric Disorders. Cereb Cortex 2018; 27:3485-3501. [PMID: 26762856 DOI: 10.1093/cercor/bhv334] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reelin-Dab1 signaling is involved in brain development and neuronal functions. The abnormalities in the signaling through either reduction of Reelin and Dab1 gene expressions or the genomic mutations in the brain have been reported to be associated with psychiatric disorders. However, it has not been clear if the deficiency in Reelin-Dab1 signaling is responsible for symptoms of the disorders. Here, to examine the function of Reelin-Dab1 signaling in the forebrain, we generated dorsal forebrain-specific Dab1 conditional knockout mouse (Dab1 cKO) and performed a behavioral test battery on the Dab1 cKO mice. Although conventional Dab1 null mutant mice exhibit cerebellar atrophy and cerebellar ataxia, the Dab1 cKO mice had normal cerebellum and showed no motor dysfunction. Dab1 cKO mice exhibited behavioral abnormalities, including hyperactivity, decreased anxiety-like behavior, and impairment of working memory, which are reminiscent of symptoms observed in patients with psychiatric disorders such as schizophrenia and bipolar disorder. These results suggest that deficiency of Reelin-Dab1 signal in the dorsal forebrain is involved in the pathogenesis of some symptoms of human psychiatric disorders.
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Affiliation(s)
- Hideaki Imai
- Division of Developmental Neurobiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Hirotaka Shoji
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan.,Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi 332-0012, Japan
| | - Masaki Ogata
- Department of Organ Anatomy, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan
| | - Yoshiteru Kagawa
- Department of Organ Anatomy, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan
| | - Yuji Owada
- Department of Organ Anatomy, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan.,Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Kawaguchi 332-0012, Japan.,Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Toshio Terashima
- Division of Developmental Neurobiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Yu Katsuyama
- Division of Developmental Neurobiology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan.,Department of Organ Anatomy, Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan
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60
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Long-Term Depression Is Independent of GluN2 Subunit Composition. J Neurosci 2018; 38:4462-4470. [PMID: 29593052 DOI: 10.1523/jneurosci.0394-18.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/16/2018] [Accepted: 03/20/2018] [Indexed: 11/21/2022] Open
Abstract
NMDA receptors (NMDARs) mediate both long-term potentiation and long-term depression (LTD) and understanding how a single receptor can initiate both phenomena remains a major question in neuroscience. A prominent hypothesis implicates the NMDAR subunit composition, specifically GluN2A and GluN2B, in dictating the rules of synaptic plasticity. However, studies testing this hypothesis have yielded inconsistent and often contradictory results, especially for LTD. These inconsistent results may be due to challenges in the interpretation of subunit-selective pharmacology and in dissecting out the contributions of differential channel properties versus the interacting proteins unique to GluN2A or GluN2B. In this study, we address the pharmacological and biochemical challenges by using a single-neuron genetic approach to delete NMDAR subunits in conditional knock-out mice. In addition, the recently discovered non-ionotropic nature of NMDAR-dependent LTD allowed the rigorous assessment of unique subunit contributions to NMDAR-dependent LTD while eliminating the variable of differential charge transfer. Here we find that neither the GluN2A nor the GluN2B subunit is strictly necessary for either non-ionotropic or ionotropic LTD.SIGNIFICANCE STATEMENT NMDA receptors are key regulators of bidirectional synaptic plasticity. Understanding the mechanisms regulating bidirectional plasticity will guide development of therapeutic strategies to treat the dysfunctional synaptic plasticity in multiple neuropsychiatric disorders. Because of the unique properties of the NMDA receptor GluN2 subunits, they have been postulated to differentially affect synaptic plasticity. However, there has been significant controversy regarding the roles of the GluN2 subunits in synaptic long term depression (LTD). Using single-neuron knock-out of the GluN2 subunits, we show that LTD requires neither GluN2A nor GluN2B.
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Yoshida H, Yamada H, Nogami W, Dohi K, Kurino-Yamada T, Sugiyama K, Takahashi K, Gahara Y, Kitaura M, Hasegawa M, Oshima I, Kuwabara K. Development of a new knock-in mouse model and evaluation of pharmacological activities of lusutrombopag, a novel, nonpeptidyl small-molecule agonist of the human thrombopoietin receptor c-Mpl. Exp Hematol 2017; 59:30-39.e2. [PMID: 29274361 DOI: 10.1016/j.exphem.2017.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/15/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
Lusutrombopag (S-888711), an oral small-molecule thrombopoietin receptor (TPOR) agonist, has gained first approval as a drug to treat thrombocytopenia of chronic liver disease in patients undergoing elective invasive procedures in Japan. Preclinical studies were performed to evaluate its efficacy against megakaryopoiesis and thrombopoiesis. To investigate the proliferative activity and efficacy of megakaryocytic colony formation via human TPOR, lusutrombopag was applied to cultured human c-Mpl-expressing Ba/F3 (Ba/F3-hMpl) cells and human bone marrow-derived CD34-positive cells, respectively. Lusutrombopag caused a robust increase in Ba/F3-hMpl cells by activating pathways in a manner similar to that of thrombopoietin and induced colony-forming units-megakaryocyte and polyploid megakaryocytes in human CD34-positive cells. Because lusutrombopag has high species specificity for human TPOR, there was no suitable experimental animal model for drug evaluation, except for immunodeficient mouse-based xenograft models. Therefore, a novel genetically modified knock-in mouse, TPOR-Ki/Shi, was developed by replacing mouse Mpl with human-mouse chimera Mpl. In TPOR-Ki/Shi mice, lusutrombopag significantly increased circulating platelets in a dose-dependent manner during 21-day repeated oral administration. Histopathological study of the TPOR-Ki/Shi mice on day 22 also revealed a significant increase in megakaryocytes in the bone marrow. These results indicate that lusutrombopag acts on human TPOR to upregulate differentiation and proliferation of megakaryocytic cells, leading to platelet production.
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Affiliation(s)
- Hiroshi Yoshida
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Hajime Yamada
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Wataru Nogami
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Keiji Dohi
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | | | - Koji Sugiyama
- Human Resources & Administration Department, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Koji Takahashi
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Yoshinari Gahara
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Motoji Kitaura
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Minoru Hasegawa
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Itsuki Oshima
- Pharmaceutical Research Division, Human Resources & Administration Department, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Kenji Kuwabara
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan.
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62
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Honda A, Usui H, Sakimura K, Igarashi M. Rufy3 is an adapter protein for small GTPases that activates a Rac guanine nucleotide exchange factor to control neuronal polarity. J Biol Chem 2017; 292:20936-20946. [PMID: 29089386 DOI: 10.1074/jbc.m117.809541] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/25/2017] [Indexed: 01/01/2023] Open
Abstract
RUN and FYVE domain-containing 3 (Rufy3) is an adapter protein for small GTPase proteins and is bound to activated Rap2, a Ras family protein in the developing neuron. Previously, we reported the presence of a rapid cell polarity determination mechanism involving Rufy3, which is likely required for in vivo neuronal development. However, the molecular details of this mechanism are unclear. To this end, here we produced Rufy3 knock-out (Rufy3-KO) mice to study the role of Rufy3 in more detail. Examining Rufy3-KO neurons, we found that Rufy3 is recruited via glycoprotein M6A to detergent-resistant membrane domains, which are biochemically similar to lipid rafts. We also clarified that Rufy3, as a component of a ternary complex, induces the assembly of Rap2 in the axonal growth cone, whereas in the absence of Rufy3, the accumulation of a Rac guanine nucleotide exchange factor, T-cell lymphoma invasion and metastasis 2 (Tiam2/STEF), is inhibited downstream of Rap2. We also found that Rufy3 regulates the cellular localization of Rap2 and Tiam2/STEF. Taken together, we conclude that Rufy3 is a physiological adapter for Rap2 and activates Tiam2/STEF in glycoprotein M6A-regulated neuronal polarity and axon growth.
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Affiliation(s)
- Atsuko Honda
- From the Department of Neurochemistry and Molecular Cell Biology.,Trans-disciplinary Research Program, and
| | - Hiroshi Usui
- Department of Cellular Neurobiology, Institute for Brain Research, Niigata University, Chuo-ku, Niigata 951-8510, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Institute for Brain Research, Niigata University, Chuo-ku, Niigata 951-8510, Japan
| | - Michihiro Igarashi
- From the Department of Neurochemistry and Molecular Cell Biology, .,Trans-disciplinary Research Program, and
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63
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Hayakawa-Yano Y, Suyama S, Nogami M, Yugami M, Koya I, Furukawa T, Zhou L, Abe M, Sakimura K, Takebayashi H, Nakanishi A, Okano H, Yano M. An RNA-binding protein, Qki5, regulates embryonic neural stem cells through pre-mRNA processing in cell adhesion signaling. Genes Dev 2017; 31:1910-1925. [PMID: 29021239 PMCID: PMC5693031 DOI: 10.1101/gad.300822.117] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/14/2017] [Indexed: 01/07/2023]
Abstract
Cell type-specific transcriptomes are enabled by the action of multiple regulators, which are frequently expressed within restricted tissue regions. In the present study, we identify one such regulator, Quaking 5 (Qki5), as an RNA-binding protein (RNABP) that is expressed in early embryonic neural stem cells and subsequently down-regulated during neurogenesis. mRNA sequencing analysis in neural stem cell culture indicates that Qki proteins play supporting roles in the neural stem cell transcriptome and various forms of mRNA processing that may result from regionally restricted expression and subcellular localization. Also, our in utero electroporation gain-of-function study suggests that the nuclear-type Qki isoform Qki5 supports the neural stem cell state. We next performed in vivo transcriptome-wide protein-RNA interaction mapping to search for direct targets of Qki5 and elucidate how Qki5 regulates neural stem cell function. Combined with our transcriptome analysis, this mapping analysis yielded a bona fide map of Qki5-RNA interaction at single-nucleotide resolution, the identification of 892 Qki5 direct target genes, and an accurate Qki5-dependent alternative splicing rule in the developing brain. Last, our target gene list provides the first compelling evidence that Qki5 is associated with specific biological events; namely, cell-cell adhesion. This prediction was confirmed by histological analysis of mice in which Qki proteins were genetically ablated, which revealed disruption of the apical surface of the lateral wall in the developing brain. These data collectively indicate that Qki5 regulates communication between neural stem cells by mediating numerous RNA processing events and suggest new links between splicing regulation and neural stem cell states.
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Affiliation(s)
- Yoshika Hayakawa-Yano
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8510, Japan
| | - Satoshi Suyama
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masahiro Nogami
- Shonan Incubation Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan.,Integrated Technology Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan
| | - Masato Yugami
- Shonan Incubation Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan.,Integrated Technology Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan
| | - Ikuko Koya
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takako Furukawa
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8510, Japan
| | - Li Zhou
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8585, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8585, Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8510, Japan
| | - Atsushi Nakanishi
- Shonan Incubation Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan.,Integrated Technology Research Laboratories, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa 251-8555, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Masato Yano
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachidori, Chuo-ku, Niigata, Niigata 951-8510, Japan.,Department of Physiology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
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64
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Miyamoto H, Shimohata A, Abe M, Abe T, Mazaki E, Amano K, Suzuki T, Tatsukawa T, Itohara S, Sakimura K, Yamakawa K. Potentiation of excitatory synaptic transmission ameliorates aggression in mice with Stxbp1 haploinsufficiency. Hum Mol Genet 2017; 26:4961-4974. [DOI: 10.1093/hmg/ddx379] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/09/2017] [Indexed: 11/13/2022] Open
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65
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Netrin-1 Derived from the Ventricular Zone, but not the Floor Plate, Directs Hindbrain Commissural Axons to the Ventral Midline. Sci Rep 2017; 7:11992. [PMID: 28931893 PMCID: PMC5607380 DOI: 10.1038/s41598-017-12269-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/31/2017] [Indexed: 11/08/2022] Open
Abstract
Netrin-1 (Ntn1) emanating from the ventral midline has been thought to act as a long-range diffusible chemoattractant for commissural axons (CAs). However, CAs still grow towards the midline in the absence of the floor plate (FP), a glial structure occupying the midline. Here, using genetically loss-of-function approaches in mice, we show that Ntn1 derived from the ventricular zone (VZ), but not the FP, is crucial for CA guidance in the mouse hindbrain. During the period of CA growth, Ntn1 is expressed in the ventral two-thirds of the VZ, in addition to the FP. Remarkably, deletion of Ntn1 from the VZ and even from the dorsal VZ highly disrupts CA guidance to the midline, whereas the deletion from the FP has little impact on it. We also show that the severities of CA guidance defects found in the Ntn1 conditional mutants were irrelevant to their FP long-range chemoattractive activities. Our results are incompatible with the prevailing view that Ntn1 is an FP-derived long-range diffusible chemoattractant for CAs, but suggest a novel mechanism that VZ-derived Ntn1 directs CAs to the ventral midline by its local actions.
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66
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Mashud R, Nomachi A, Hayakawa A, Kubouchi K, Danno S, Hirata T, Matsuo K, Nakayama T, Satoh R, Sugiura R, Abe M, Sakimura K, Wakana S, Ohsaki H, Kamoshida S, Mukai H. Impaired lymphocyte trafficking in mice deficient in the kinase activity of PKN1. Sci Rep 2017; 7:7663. [PMID: 28794483 PMCID: PMC5550459 DOI: 10.1038/s41598-017-07936-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/05/2017] [Indexed: 12/11/2022] Open
Abstract
Knock-in mice lacking PKN1 kinase activity were generated by introducing a T778A point mutation in the catalytic domain. PKN1[T778A] mutant mice developed to adulthood without apparent external abnormalities, but exhibited lower T and B lymphocyte counts in the peripheral blood than those of wild-type (WT) mice. T and B cell development proceeded in an apparently normal fashion in bone marrow and thymus of PKN1[T778A] mice, however, the number of T and B cell counts were significantly higher in the lymph nodes and spleen of mutant mice in those of WT mice. After transfusion into WT recipients, EGFP-labelled PKN1[T778A] donor lymphocytes were significantly less abundant in the peripheral circulation and more abundant in the spleen and lymph nodes of recipient mice compared with EGFP-labelled WT donor lymphocytes, likely reflecting lymphocyte sequestration in the spleen and lymph nodes in a cell-autonomous fashion. PKN1[T778A] lymphocytes showed significantly lower chemotaxis towards chemokines and sphingosine 1-phosphate (S1P) than WT cells in vitro. The biggest migration defect was observed in response to S1P, which is essential for lymphocyte egress from secondary lymphoid organs. These results reveal a novel role of PKN1 in lymphocyte migration and localization.
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Affiliation(s)
- Rana Mashud
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Akira Nomachi
- Center for Innovation in Immunoregulative Technology and Therapeutics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihide Hayakawa
- Graduate School of Science and Technology, Kobe University, Kobe, 657-8501, Japan
| | - Koji Kubouchi
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Sally Danno
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Takako Hirata
- Department of Fundamental Biosciences, Shiga University of Medical Science, Seta-Tsukinowa-cho Otsu, Shiga, 520-2192, Japan
| | - Kazuhiko Matsuo
- Division of Chemotherapy, Kindai University School of Pharmacy, Kowakae, Higashi-Osaka, 577-8502, Japan
| | - Takashi Nakayama
- Division of Chemotherapy, Kindai University School of Pharmacy, Kowakae, Higashi-Osaka, 577-8502, Japan
| | - Ryosuke Satoh
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kindai University, 3-4-1, Kowakae, Higashi-Osaka, 577-8502, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, School of Pharmaceutical Sciences, Kindai University, 3-4-1, Kowakae, Higashi-Osaka, 577-8502, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Shigeharu Wakana
- Japan Mouse Clinic, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba-shi, Ibaraki, 305-0074, Japan
| | - Hiroyuki Ohsaki
- Laboratory of Pathology, Department of Medical Biophysics, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma, Kobe, Hyogo, 654-0142, Japan
| | - Shingo Kamoshida
- Laboratory of Pathology, Department of Medical Biophysics, Kobe University Graduate School of Health Sciences, 7-10-2 Tomogaoka, Suma, Kobe, Hyogo, 654-0142, Japan
| | - Hideyuki Mukai
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan.
- Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan.
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67
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Kakizaki T, Sakagami H, Sakimura K, Yanagawa Y. A glycine transporter 2-Cre knock-in mouse line for glycinergic neuron-specific gene manipulation. IBRO Rep 2017; 3:9-16. [PMID: 30135938 PMCID: PMC6084908 DOI: 10.1016/j.ibror.2017.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/24/2017] [Accepted: 07/24/2017] [Indexed: 01/16/2023] Open
Abstract
Glycine is an inhibitory neurotransmitter in the brainstem and spinal cord. Glycine transporter 2 (GLYT2) is responsible for the uptake of extracellular glycine. GLYT2 is specifically expressed in glycinergic neurons and thus has been used as a marker of glycinergic neurons. Here, we generated GLYT2 promotor-driven Cre recombinase (Cre)-expressing mice (GLYT2-Cre knock-in mice) to develop a tool for manipulating gene expression in glycinergic neurons. Cre activity was examined by crossing the GLYT2-Cre knock-in mice with a Cre reporter mouse line, R26R, which express β-galactosidase (β-gal) in a Cre-dependent manner. X-gal staining of GLYT2-Cre/R26R double transgenic mouse brains and spinal cords revealed that the Cre activity was primarily distributed in the brainstem, cerebellum, and spinal cord. These areas are rich in glycinergic neurons. Furthermore, we performed immunohistochemistry for β-gal combined with in situ hybridization for GLYT2 in the GLYT2-Cre/R26R double transgenic mouse brains to determine whether Cre activity is specifically localized to glycinergic neurons. The β-gal protein and GLYT2 mRNAs were colocalized in the cerebellar Golgi cells, dorsal cochlear nucleus, gigantocellular reticular nucleus, spinal trigeminal nucleus, nucleus of the trapezoid body, and lateral lemniscus. More than 98% of the GLYT2 mRNA-expressing cells in these brain regions also expressed β-gal, whereas 90–98% of the β-gal-positive cells expressed the GLYT2 mRNAs. Thus, Cre activity is specifically localized to glycinergic neurons with high fidelity in the GLYT2-Cre knock-in mice. The GLYT2-Cre knock-in mouse line will be a useful tool for studying glycinergic neurons and neurotransmission.
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Affiliation(s)
- Toshikazu Kakizaki
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 228-8555, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi 371-8511, Japan
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68
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Kawai T, Okochi Y, Ozaki T, Imura Y, Koizumi S, Yamazaki M, Abe M, Sakimura K, Yamashita T, Okamura Y. Unconventional role of voltage‐gated proton channels (
VSOP
/Hv1) in regulation of microglial
ROS
production. J Neurochem 2017. [DOI: 10.1111/jnc.14106] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Takafumi Kawai
- Integrative Physiology Department of Physiology Graduate School of Medicine & Frontier Biosciences Osaka University Suita Osaka Japan
| | - Yoshifumi Okochi
- Integrative Physiology Department of Physiology Graduate School of Medicine & Frontier Biosciences Osaka University Suita Osaka Japan
| | - Tomohiko Ozaki
- Department of Molecular Neuroscience Graduate School of Medicine Osaka University Suita Osaka Japan
| | - Yoshio Imura
- Department of Neuropharmacology Interdisciplinary Graduate School of Medicine University of Yamanashi Chuo Yamanashi Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology Interdisciplinary Graduate School of Medicine University of Yamanashi Chuo Yamanashi Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology Brain Research Institute Niigata University Niigata Japan
| | - Manabu Abe
- Department of Cellular Neurobiology Brain Research Institute Niigata University Niigata Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology Brain Research Institute Niigata University Niigata Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience Graduate School of Medicine Osaka University Suita Osaka Japan
| | - Yasushi Okamura
- Integrative Physiology Department of Physiology Graduate School of Medicine & Frontier Biosciences Osaka University Suita Osaka Japan
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69
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The number and distribution of AMPA receptor channels containing fast kinetic GluA3 and GluA4 subunits at auditory nerve synapses depend on the target cells. Brain Struct Funct 2017; 222:3375-3393. [PMID: 28397107 PMCID: PMC5676837 DOI: 10.1007/s00429-017-1408-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 03/20/2017] [Indexed: 02/07/2023]
Abstract
The neurotransmitter receptor subtype, number, density, and distribution relative to the location of transmitter release sites are key determinants of signal transmission. AMPA-type ionotropic glutamate receptors (AMPARs) containing GluA3 and GluA4 subunits are prominently expressed in subsets of neurons capable of firing action potentials at high frequencies, such as auditory relay neurons. The auditory nerve (AN) forms glutamatergic synapses on two types of relay neurons, bushy cells (BCs) and fusiform cells (FCs) of the cochlear nucleus. AN-BC and AN-FC synapses have distinct kinetics; thus, we investigated whether the number, density, and localization of GluA3 and GluA4 subunits in these synapses are differentially organized using quantitative freeze-fracture replica immunogold labeling. We identify a positive correlation between the number of AMPARs and the size of AN-BC and AN-FC synapses. Both types of AN synapses have similar numbers of AMPARs; however, the AN-BC have a higher density of AMPARs than AN-FC synapses, because the AN-BC synapses are smaller. A higher number and density of GluA3 subunits are observed at AN-BC synapses, whereas a higher number and density of GluA4 subunits are observed at AN-FC synapses. The intrasynaptic distribution of immunogold labeling revealed that AMPAR subunits, particularly GluA3, are concentrated at the center of the AN-BC synapses. The central distribution of AMPARs is absent in GluA3-knockout mice, and gold particles are evenly distributed along the postsynaptic density. GluA4 gold labeling was homogenously distributed along both synapse types. Thus, GluA3 and GluA4 subunits are distributed at AN synapses in a target-cell-dependent manner.
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70
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Ohki K, Wakui H, Azushima K, Uneda K, Haku S, Kobayashi R, Haruhara K, Kinguchi S, Matsuda M, Ohsawa M, Maeda A, Minegishi S, Ishigami T, Toya Y, Yamashita A, Umemura S, Tamura K. ATRAP Expression in Brown Adipose Tissue Does Not Influence the Development of Diet-Induced Metabolic Disorders in Mice. Int J Mol Sci 2017; 18:ijms18030676. [PMID: 28335584 PMCID: PMC5372686 DOI: 10.3390/ijms18030676] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/09/2017] [Accepted: 03/16/2017] [Indexed: 12/11/2022] Open
Abstract
Activation of tissue renin-angiotensin system (RAS), mainly mediated by an angiotensin II (Ang II) type 1 receptor (AT1R), plays an important role in the development of obesity-related metabolic disorders. We have shown that AT1R-associated protein (ATRAP), a specific binding protein of AT1R, functions as an endogenous inhibitor to prevent excessive activation of tissue RAS. In the present study, we newly generated ATRAP/Agtrap-floxed (ATRAPfl/fl) mice and adipose tissue-specific ATRAP downregulated (ATRAPadipoq) mice by the Cre/loxP system using Adipoq-Cre. Using these mice, we examined the functional role of adipose ATRAP in the pathogenesis of obesity-related metabolic disorders. Compared with ATRAPfl/fl mice, ATRAPadipoq mice exhibited a decreased ATRAP expression in visceral white adipose tissue (WAT) and brown adipose tissue (BAT) by approximately 30% and 85%, respectively. When mice were fed a high-fat diet, ATRAPfl/fl mice showed decreased endogenous ATRAP expression in WAT that was equivalent to ATRAPadipoq mice, and there was no difference in the exacerbation of dietary obesity and glucose and lipid metabolism. These results indicate that ATRAP in BAT does not influence the pathogenesis of dietary obesity or metabolic disorders. Future studies that modulate ATRAP in WAT are necessary to assess its in vivo functions in the development of obesity-related metabolic disorders.
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Affiliation(s)
- Kohji Ohki
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Hiromichi Wakui
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Kengo Azushima
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
- Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore.
| | - Kazushi Uneda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Sona Haku
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Ryu Kobayashi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Kotaro Haruhara
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Sho Kinguchi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Miyuki Matsuda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Masato Ohsawa
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Akinobu Maeda
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Shintaro Minegishi
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Tomoaki Ishigami
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Yoshiyuki Toya
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Akio Yamashita
- Department of Molecular Biology, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
| | - Satoshi Umemura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
- Yokohama Rosai Hospital, 3211 Kozukue-cho, Kohoku-ku, Yokohama 222-0036, Japan.
| | - Kouichi Tamura
- Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
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Shimizu T, Wisessmith W, Li J, Abe M, Sakimura K, Chetsawang B, Sahara Y, Tohyama K, Tanaka KF, Ikenaka K. The balance between cathepsin C and cystatin F controls remyelination in the brain ofPlp1-overexpressing mouse, a chronic demyelinating disease model. Glia 2017; 65:917-930. [DOI: 10.1002/glia.23134] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 02/03/2017] [Accepted: 02/10/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Takahiro Shimizu
- Division of Neurobiology and Bioinformatics; National Institute for Physiological Sciences; Okazaki Japan
| | - Wilaiwan Wisessmith
- Division of Neurobiology and Bioinformatics; National Institute for Physiological Sciences; Okazaki Japan
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University; Salaya Nakhonpathom Thailand
| | - Jiayi Li
- Division of Neurobiology and Bioinformatics; National Institute for Physiological Sciences; Okazaki Japan
- Department of Physiological Sciences; Graduate University for Advanced Studies (SOKENDAI); Okazaki Japan
| | - Manabu Abe
- Brain Research Institute, Niigata University; Niigata Japan
| | - Kenji Sakimura
- Brain Research Institute, Niigata University; Niigata Japan
| | - Banthit Chetsawang
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University; Salaya Nakhonpathom Thailand
| | - Yoshinori Sahara
- Department of Physiology; Iwate Medical University School of Dentistry; Iwate Japan
| | - Koujiro Tohyama
- Department of Physiology; Iwate Medical University School of Dentistry; Iwate Japan
- Center for Electron Microscopy and Bio-Imaging Research, Iwate Medical University; Iwate Japan
| | - Kenji F. Tanaka
- Division of Neurobiology and Bioinformatics; National Institute for Physiological Sciences; Okazaki Japan
- Department of Neuropsychiatry; Keio University; Tokyo Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics; National Institute for Physiological Sciences; Okazaki Japan
- Department of Physiological Sciences; Graduate University for Advanced Studies (SOKENDAI); Okazaki Japan
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72
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PNPLA1 has a crucial role in skin barrier function by directing acylceramide biosynthesis. Nat Commun 2017; 8:14609. [PMID: 28248300 PMCID: PMC5337976 DOI: 10.1038/ncomms14609] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 01/10/2017] [Indexed: 02/07/2023] Open
Abstract
Mutations in patatin-like phospholipase domain-containing 1 (PNPLA1) cause autosomal recessive congenital ichthyosis, but the mechanism involved remains unclear. Here we show that PNPLA1, an enzyme expressed in differentiated keratinocytes, plays a crucial role in the biosynthesis of ω-O-acylceramide, a lipid component essential for skin barrier. Global or keratinocyte-specific Pnpla1-deficient neonates die due to epidermal permeability barrier defects with severe transepidermal water loss, decreased intercellular lipid lamellae in the stratum corneum, and aberrant keratinocyte differentiation. In Pnpla1−/− epidermis, unique linoleate-containing lipids including acylceramides, acylglucosylceramides and (O-acyl)-ω-hydroxy fatty acids are almost absent with reciprocal increases in their putative precursors, indicating that PNPLA1 catalyses the ω-O-esterification with linoleic acid to form acylceramides. Moreover, acylceramide supplementation partially rescues the altered differentiation of Pnpla1−/− keratinocytes. Our findings provide valuable insight into the skin barrier formation and ichthyosis development, and may contribute to novel therapeutic strategies for treatment of epidermal barrier defects. Loss-of-function mutations in PNPLA1, a gene encoding an enzyme with unknown function, cause dry and scaling skin in humans. Using mouse models with PNPLA1 deficiency, the authors show that PNPLA1 participates in the biosynthesis of acylceramide, a lipid component essential for skin barrier function.
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73
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Danno S, Kubouchi K, Mehruba M, Abe M, Natsume R, Sakimura K, Eguchi S, Oka M, Hirashima M, Yasuda H, Mukai H. PKN2 is essential for mouse embryonic development and proliferation of mouse fibroblasts. Genes Cells 2017; 22:220-236. [PMID: 28102564 DOI: 10.1111/gtc.12470] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/21/2016] [Indexed: 12/17/2022]
Abstract
PKN2, a member of the protein kinase N (PKN) family, has been suggested by in vitro culture cell experiments to bind to Rho/Rac GTPases and contributes to cell-cell contact and cell migration. To unravel the in vivo physiological function of PKN2, we targeted the PKN2 gene. Constitutive disruption of the mouse PKN2 gene resulted in growth retardation and lethality before embryonic day (E) 10.5. PKN2-/- embryo did not undergo axial turning and showed insufficient closure of the neural tube. Mouse embryonic fibroblasts (MEFs) derived from PKN2-/- embryos at E9.5 failed to grow. Cre-mediated ablation of PKN2 in PKN2flox/flox MEFs obtained from E14.5 embryos showed impaired cell proliferation, and cell cycle analysis of these MEFs showed a decrease in S-phase population. Our results show that PKN2 is essential for mouse embryonic development and cell-autonomous proliferation of primary MEFs in culture. Comparison of the PKN2-/- phenotype with the phenotypes of PKN1 and PKN3 knockout strains suggests that PKN2 has distinct nonredundant functions in vivo, despite the structural similarity and evolutionary relationship among the three isoforms.
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Affiliation(s)
- Sally Danno
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Koji Kubouchi
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Mona Mehruba
- Graduate School of Medicine, Kobe University, Kobe, 650-0017, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Satoshi Eguchi
- Department of Medical Biology, Akita University Graduate School of Medicine, Akita, 010-8543, Japan
| | - Masahiro Oka
- Division of Dermatology, Tohoku Medical and Pharmaceutical University, 1-12-1 Fukumuro, Miyagino-ku, Sendai, 983-8512, Japan
| | | | - Hiroki Yasuda
- Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, 371-8511, Japan
| | - Hideyuki Mukai
- Biosignal Research Center, Kobe University, Kobe, 657-8501, Japan
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74
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García-Hernández S, Abe M, Sakimura K, Rubio ME. Impaired auditory processing and altered structure of the endbulb of Held synapse in mice lacking the GluA3 subunit of AMPA receptors. Hear Res 2016; 344:284-294. [PMID: 28011083 DOI: 10.1016/j.heares.2016.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 10/28/2016] [Accepted: 12/12/2016] [Indexed: 02/07/2023]
Abstract
AMPA glutamate receptor complexes with fast kinetics conferred by subunits like GluA3 and GluA4 are essential for temporal precision of synaptic transmission. The specific role of GluA3 in auditory processing and experience related changes in the auditory brainstem remain unknown. We investigated the role of the GluA3 in auditory processing by using wild type (WT) and GluA3 knockout (GluA3-KO) mice. We recorded auditory brainstem responses (ABR) to assess auditory function and used electron microscopy to evaluate the ultrastructure of the auditory nerve synapse on bushy cells (AN-BC synapse). Since labeling for GluA3 subunit increases on auditory nerve synapses within the cochlear nucleus in response to transient sound reduction, we investigated the role of GluA3 in experience-dependent changes in auditory processing. We induced transient sound reduction by plugging one ear and evaluated ABR threshold and peak amplitude recovery for up to 60 days after ear plug removal in WT and GluA3-KO mice. We found that the deletion of GluA3 leads to impaired auditory signaling that is reflected in decreased ABR peak amplitudes, an increased latency of peak 2, early onset hearing loss and reduced numbers and sizes of postsynaptic densities (PSDs) of AN-BC synapses. Additionally, the lack of GluA3 hampers ABR threshold recovery after transient ear plugging. We conclude that GluA3 is required for normal auditory signaling, normal ultrastructure of AN-BC synapses in the cochlear nucleus and normal experience-dependent changes in auditory processing after transient sound reduction.
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Affiliation(s)
- Sofía García-Hernández
- Department of Otolaryngology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA
| | - Manabu Abe
- Niigata University Brain Research Institute, Japan
| | | | - María E Rubio
- Department of Otolaryngology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA; Department of Neurobiology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, School of Medicine, Pittsburgh, PA, USA.
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75
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Shimizu T, Osanai Y, Tanaka KF, Abe M, Natsume R, Sakimura K, Ikenaka K. YAP functions as a mechanotransducer in oligodendrocyte morphogenesis and maturation. Glia 2016; 65:360-374. [PMID: 27807898 DOI: 10.1002/glia.23096] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 10/17/2016] [Indexed: 11/06/2022]
Abstract
Oligodendrocytes (OLs) are myelinating cells of the central nervous system. Recent studies have shown that mechanical factors influence various cell properties. Mechanical stimuli can be transduced into intracellular biochemical signals through mechanosensors and intracellular mechanotransducers, such as YAP. However, the molecular mechanisms underlying mechanical regulation of OLs by YAP remain unknown. We found that OL morphology and interactions between OLs and neuronal axons were affected by knocking down YAP. Mechanical stretching of OL precursor cells induced nuclear YAP accumulation and assembly of focal adhesion, key platforms for mechanotransduction. Shear stress decreased the number of OL processes, whereas a dominant-negative form of YAP suppressed these effects. To investigate the roles of YAP in postnatal OLs in vivo, we constructed a novel YAP knock-in mouse and found that in vivo overexpression of YAP widely affected OL maturation. These results indicate that YAP regulates OL morphology and maturation in response to mechanical factors. GLIA 2017;65:360-374.
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Affiliation(s)
- Takeshi Shimizu
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.,Department of Physiological Sciences, School of Life Sciences, SOKENDAI, (The Graduate University for Advanced Studies), Okazaki, Aichi, 444-8585, Japan
| | - Yasuyuki Osanai
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.,Department of Physiological Sciences, School of Life Sciences, SOKENDAI, (The Graduate University for Advanced Studies), Okazaki, Aichi, 444-8585, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, 160-8582, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan.,Department of Physiological Sciences, School of Life Sciences, SOKENDAI, (The Graduate University for Advanced Studies), Okazaki, Aichi, 444-8585, Japan
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76
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Shimizu K, Kobayashi Y, Nakatsuji E, Yamazaki M, Shimba S, Sakimura K, Fukada Y. SCOP/PHLPP1β mediates circadian regulation of long-term recognition memory. Nat Commun 2016; 7:12926. [PMID: 27686624 PMCID: PMC5056436 DOI: 10.1038/ncomms12926] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 08/16/2016] [Indexed: 01/07/2023] Open
Abstract
Learning and memory depend on the time of day in various organisms, but it is not clear whether and how the circadian clock regulates memory performance. Here we show that consolidation of long-term recognition memory is a circadian-regulated process, which is blunted by disruption of the hippocampal clock. We focused on SCOP, a key molecule regulating hippocampus-dependent long-term memory for objects. The amounts of SCOP and its binding partner K-Ras in the hippocampal membrane rafts exhibit robust circadian changes, and SCOP knockdown in the hippocampal CA1 impairs long-term memory at night. Circadian changes in stimulus-dependent activation of ERK in the hippocampal neurons are dependent on the SCOP levels in the membrane rafts, while Scop knockout abrogates the activation rhythm. We conclude that long-term memory formation is regulated by the circadian clock through SCOP dynamics in the membrane rafts of the hippocampal CA1. Learning and memory are subject to circadian variation, though the molecular mechanisms behind this are unclear. Here, the authors show SCOP, a regulator of hippocampal memory, undergoes circadian changes in CA1 membrane raft dynamics and contributes to time-dependent changes in long-term memory.
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Affiliation(s)
- Kimiko Shimizu
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yodai Kobayashi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Erika Nakatsuji
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Shigeki Shimba
- Department of Health Science, School of Pharmacology, Nihon University, Chiba 274-8555, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Yoshitaka Fukada
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
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77
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Distribution of corticotropin-releasing factor neurons in the mouse brain: a study using corticotropin-releasing factor-modified yellow fluorescent protein knock-in mouse. Brain Struct Funct 2016; 222:1705-1732. [PMID: 27638512 DOI: 10.1007/s00429-016-1303-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 09/02/2016] [Indexed: 10/21/2022]
Abstract
We examined the morphological features of corticotropin-releasing factor (CRF) neurons in a mouse line in which modified yellow fluorescent protein (Venus) was expressed under the CRF promoter. We previously generated the CRF-Venus knock-in mouse, in which Venus is inserted into the CRF gene locus by homologous recombination. In the present study, the neomycin phosphotransferase gene (Neo), driven by the pgk-1 promoter, was deleted from the CRF-Venus mouse genome, and a CRF-Venus∆Neo mouse was generated. Venus expression is much more prominent in the CRF-Venus∆Neo mouse when compared to the CRF-Venus mouse. In addition, most Venus-expressing neurons co-express CRF mRNA. Venus-expressing neurons constitute a discrete population of neuroendocrine neurons in the paraventricular nucleus of the hypothalamus (PVH) that project to the median eminence. Venus-expressing neurons were also found in brain regions outside the neuroendocrine PVH, including the olfactory bulb, the piriform cortex (Pir), the extended amygdala, the hippocampus, the neocortices, Barrington's nucleus, the midbrain/pontine dorsal tegmentum, the periaqueductal gray, and the inferior olivary nucleus (IO). Venus-expressing perikarya co-expressing CRF mRNA could be observed clearly even in regions where CRF-immunoreactive perikarya could hardly be identified. We demonstrated that the CRF neurons contain glutamate in the Pir and IO, while they contain gamma-aminobutyric acid in the neocortex, the bed nucleus of the stria terminalis, the hippocampus, and the amygdala. A population of CRF neurons was demonstrated to be cholinergic in the midbrain tegmentum. The CRF-Venus∆Neo mouse may be useful for studying the structural and functional properties of CRF neurons in the mouse brain.
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78
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Cho WH, Han JS. Differences in the Flexibility of Switching Learning Strategies and CREB Phosphorylation Levels in Prefrontal Cortex, Dorsal Striatum and Hippocampus in Two Inbred Strains of Mice. Front Behav Neurosci 2016; 10:176. [PMID: 27695401 PMCID: PMC5025447 DOI: 10.3389/fnbeh.2016.00176] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/01/2016] [Indexed: 01/28/2023] Open
Abstract
Flexibility in using different learning strategies was assessed in two different inbred strains of mice, the C57BL/6 and DBA/2 strains. Mice were trained sequentially in two different Morris water maze protocols that tested their ability to switch their learning strategy to complete a new task after first being trained in a different task. Training consisted either of visible platform trials (cued training) followed by subsequent hidden platform trials (place training) or the reverse sequence (place training followed by cued training). Both strains of mice showed equivalent performance in the type of training (cued or place) that they received first. However, C57BL/6 mice showed significantly better performances than DBA/2 mice following the switch in training protocols, irrespective of the order of training. After completion of the switched training session, levels of cAMP response element-binding protein (CREB) and phosphorylated CREB (pCREB) were measured in the hippocampus, striatum and prefrontal cortex of the mice. Prefrontal cortical and hippocampal pCREB levels differed by strain, with higher levels found in C57BL/6 mice than in DBA/2 mice. No strain differences were observed in the medial or lateral region of the dorsal striatum. These findings indicate that the engagement (i.e., CREB signaling) of relevant neural structures may vary by the specific demands of the learning strategy, and this is closely tied to differences in the flexibility of C57BL/6 and DBA/2 mice to switch their learning strategies when given a new task.
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Affiliation(s)
- Woo-Hyun Cho
- Department of Biological Sciences, Konkuk University Seoul, South Korea
| | - Jung-Soo Han
- Department of Biological Sciences, Konkuk University Seoul, South Korea
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79
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TARP γ-2 and γ-8 Differentially Control AMPAR Density Across Schaffer Collateral/Commissural Synapses in the Hippocampal CA1 Area. J Neurosci 2016; 36:4296-312. [PMID: 27076426 DOI: 10.1523/jneurosci.4178-15.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/19/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The number of AMPA-type glutamate receptors (AMPARs) at synapses is the major determinant of synaptic strength and varies from synapse to synapse. To clarify the underlying molecular mechanisms, the density of AMPARs, PSD-95, and transmembrane AMPAR regulatory proteins (TARPs) were compared at Schaffer collateral/commissural (SCC) synapses in the adult mouse hippocampal CA1 by quantitative immunogold electron microscopy using serial sections. We examined four types of SCC synapses: perforated and nonperforated synapses on pyramidal cells and axodendritic synapses on parvalbumin-positive (PV synapse) and pravalbumin-negative interneurons (non-PV synapse). SCC synapses were categorized into those expressing high-density (perforated and PV synapses) or low-density (nonperforated and non-PV synapses) AMPARs. Although the density of PSD-95 labeling was fairly constant, the density and composition of TARP isoforms was highly variable depending on the synapse type. Of the three TARPs expressed in hippocampal neurons, the disparity in TARP γ-2 labeling was closely related to that of AMPAR labeling. Importantly, AMPAR density was significantly reduced at perforated and PV synapses in TARP γ-2-knock-out (KO) mice, resulting in a virtual loss of AMPAR disparity among SCC synapses. In comparison, TARP γ-8 was the only TARP expressed at nonperforated synapses, where AMPAR labeling further decreased to a background level in TARP γ-8-KO mice. These results show that synaptic inclusion of TARP γ-2 potently increases AMPAR expression and transforms low-density synapses into high-density ones, whereas TARP γ-8 is essential for low-density or basal expression of AMPARs at nonperforated synapses. Therefore, these TARPs are critically involved in AMPAR density control at SCC synapses. SIGNIFICANCE STATEMENT Although converging evidence implicates the importance of transmembrane AMPA-type glutamate receptor (AMPAR) regulatory proteins (TARPs) in AMPAR stabilization during basal transmission and synaptic plasticity, how they control large disparities in AMPAR numbers or densities across central synapses remains largely unknown. We compared the density of AMPARs with that of TARPs among four types of Schaffer collateral/commissural (SCC) hippocampal synapses in wild-type and TARP-knock-out mice. We show that the density of AMPARs correlates with that of TARP γ-2 across SCC synapses and its high expression is linked to high-density AMPAR expression at perforated type of pyramidal cell synapses and synapses on parvalbumin-positive interneurons. In comparison, TARP γ-8 is the only TARP expressed at nonperforated type of pyramidal cell synapses, playing an essential role in low-density or basal AMPAR expression.
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80
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Katano T, Fukuda M, Furue H, Yamazaki M, Abe M, Watanabe M, Nishida K, Yao I, Yamada A, Hata Y, Okumura N, Nakazawa T, Yamamoto T, Sakimura K, Takao T, Ito S. Involvement of Brain-Enriched Guanylate Kinase-Associated Protein (BEGAIN) in Chronic Pain after Peripheral Nerve Injury. eNeuro 2016; 3:ENEURO.0110-16.2016. [PMID: 27785460 PMCID: PMC5066261 DOI: 10.1523/eneuro.0110-16.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/01/2016] [Accepted: 10/04/2016] [Indexed: 02/07/2023] Open
Abstract
Maintenance of neuropathic pain caused by peripheral nerve injury crucially depends on the phosphorylation of GluN2B, a subunit of the N-methyl-d-aspartate (NMDA) receptor, at Tyr1472 (Y1472) and subsequent formation of a postsynaptic density (PSD) complex of superficial spinal dorsal horn neurons. Here we took advantage of comparative proteomic analysis based on isobaric stable isotope tags (iTRAQ) between wild-type and knock-in mice with a mutation of Y1472 to Phe of GluN2B (Y1472F-KI) to search for PSD proteins in the spinal dorsal horn that mediate the signaling downstream of phosphorylated Y1472 GluN2B. Among several candidate proteins, we focused on brain-enriched guanylate kinase-associated protein (BEGAIN), which was specifically up-regulated in wild-type mice after spared nerve injury (SNI). Immunohistochemical analysis using the generated antibody demonstrated that BEGAIN was highly localized at the synapse of inner lamina II in the spinal dorsal horn and that its expression was up-regulated after SNI in wild-type, but not in Y1472F-KI, mice. In addition, alteration of the kinetics of evoked excitatory postsynaptic currents for NMDA but not those for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in spinal lamina II was demonstrated by BEGAIN deletion. We demonstrated that mechanical allodynia, a condition of abnormal pain induced by innocuous stimuli, in the SNI model was significantly attenuated in BEGAIN-deficient mice. However, there was no significant difference between naive wild-type and BEGAIN-knockout mice in terms of physiological threshold for mechanical stimuli. These results suggest that BEGAIN was involved in pathological pain transmission through NMDA receptor activation by the phosphorylation of GluN2B at Y1472 in spinal inner lamina II.
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Affiliation(s)
- Tayo Katano
- Department of Medical Chemistry, Kansai Medical University, Hirakata 573-1010, Japan
| | - Masafumi Fukuda
- Laboratory of Protein Profiling and Functional Proteomics, Institute for Protein Research, Osaka University, Suita 565-0871, Japan
| | - Hidemasa Furue
- Division of Neural Signaling, Department of Information Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
- Department of Neurology, University of California, San Francisco, CA 94158
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University School of Medicine, Sapporo 060-8638, Japan
| | - Kazuhiko Nishida
- Department of Medical Chemistry, Kansai Medical University, Hirakata 573-1010, Japan
| | - Ikuko Yao
- Department of Medical Chemistry, Kansai Medical University, Hirakata 573-1010, Japan
- Department of Optical Imaging, Institute for Medical Photonics Research, Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Akihiro Yamada
- Division of Neural Signaling, Department of Information Physiology, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Yutaka Hata
- Department of Medical Biochemistry, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
| | - Nobuaki Okumura
- Laboratory of Homeostatic Integration, Institute for Protein Research, Osaka University, Suita 565-0871, Japan
| | - Takanobu Nakazawa
- Drug Innovation Center, Graduate School of Pharmaceutical Science, Osaka University, Suita, 565-0871, Japan
| | - Tadashi Yamamoto
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa 904-0495, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Toshifumi Takao
- Laboratory of Protein Profiling and Functional Proteomics, Institute for Protein Research, Osaka University, Suita 565-0871, Japan
| | - Seiji Ito
- Department of Medical Chemistry, Kansai Medical University, Hirakata 573-1010, Japan
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Konno A, Ikegami K, Konishi Y, Yang HJ, Abe M, Yamazaki M, Sakimura K, Yao I, Shiba K, Inaba K, Setou M. Ttll9-/- mice sperm flagella show shortening of doublet 7, reduction of doublet 5 polyglutamylation and a stall in beating. J Cell Sci 2016; 129:2757-66. [PMID: 27257088 DOI: 10.1242/jcs.185983] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/31/2016] [Indexed: 12/27/2022] Open
Abstract
Nine outer doublet microtubules in axonemes of flagella and cilia are heterogeneous in structure and biochemical properties. In mammalian sperm flagella, one of the factors to generate the heterogeneity is tubulin polyglutamylation, although the importance of the heterogeneous modification is unclear. Here, we show that a tubulin polyglutamylase Ttll9 deficiency (Ttll9(-/-)) causes a unique set of phenotypes related to doublet heterogeneity. Ttll9(-/-) sperm axonemes had frequent loss of a doublet and reduced polyglutamylation. Intriguingly, the doublet loss selectively occurred at the distal region of doublet 7, and reduced polyglutamylation was observed preferentially on doublet 5. Ttll9(-/-) spermatozoa showed aberrant flagellar beating, characterized by frequent stalls after anti-hook bending. This abnormal motility could be attributed to the reduction of polyglutamylation on doublet 5, which probably occurred at a position involved in the switching of bending. These results indicate that mammalian Ttll9 plays essential roles in maintaining the normal structure and beating pattern of sperm flagella by establishing normal heterogeneous polyglutamylation patterns.
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Affiliation(s)
- Alu Konno
- Department of Cellular and Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan
| | - Koji Ikegami
- Department of Cellular and Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan
| | - Yoshiyuki Konishi
- Department of Cellular and Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan
| | - Hyun-Jeong Yang
- Department of Cellular and Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 9518585, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 9518585, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 9518585, Japan
| | - Ikuko Yao
- Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka 4150025, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka 4150025, Japan
| | - Mitsutoshi Setou
- Department of Cellular and Molecular Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan Preeminent Medical Photonics Education & Research Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 4313192, Japan Department of Anatomy, The University of Hong Kong, 6/F, William MW Mong Block, 21 Sassoon Road, Pokfulam, Hong Kong SAR, China Division of Neural Systematics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 4440867, Japan Riken Center for Molecular Imaging Science, Kobe, Hyogo 6500047, Japan
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82
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Gerlai R. Gene Targeting Using Homologous Recombination in Embryonic Stem Cells: The Future for Behavior Genetics? Front Genet 2016; 7:43. [PMID: 27148349 PMCID: PMC4826881 DOI: 10.3389/fgene.2016.00043] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/14/2016] [Indexed: 12/27/2022] Open
Abstract
Gene targeting with homologous recombination in embryonic stem cells created a revolution in the analysis of the function of genes in behavioral brain research. The technology allowed unprecedented precision with which one could manipulate genes and study the effect of this manipulation on the central nervous system. With gene targeting, the uncertainty inherent in psychopharmacology regarding whether a particular compound would act only through a specific target was removed. Thus, gene targeting became highly popular. However, with this popularity came the realization that like other methods, gene targeting also suffered from some technical and principal problems. For example, two decades ago, issues about compensatory changes and about genetic linkage were raised. Since then, the technology developed, and its utility has been better delineated. This review will discuss the pros and cons of the technique along with these advancements from the perspective of the neuroscientist user. It will also compare and contrast methods that may represent novel alternatives to the homologous recombination based gene targeting approach, including the TALEN and the CRISPR/Cas9 systems. The goal of the review is not to provide detailed recipes, but to attempt to present a short summary of these approaches a behavioral geneticist or neuroscientist may consider for the analysis of brain function and behavior.
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Affiliation(s)
- Robert Gerlai
- Department of Cell & Systems Biology and Department of Psychology, University of Toronto MississaugaMississauga, ON, Canada
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83
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Trifonov S, Yamashita Y, Kase M, Maruyama M, Sugimoto T. Overview and assessment of the histochemical methods and reagents for the detection of β-galactosidase activity in transgenic animals. Anat Sci Int 2016; 91:56-67. [PMID: 26394634 PMCID: PMC4679788 DOI: 10.1007/s12565-015-0300-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/24/2015] [Indexed: 11/29/2022]
Abstract
Bacterial β-galactosidase is one of the most widely used reporter genes in experiments involving transgenic and knockout animals. In this review we discuss the current histochemical methods and available reagents to detect β-galactosidase activity. Different substrates are available, but the most commonly used is X-gal in combination with potassium ferri- and ferro-cyanide. The reaction produces a characteristic blue precipitate in the cells expressing β-galactosidase, and despite its efficiency in staining whole embryos, its detection on thin tissue sections is difficult. Salmon-gal is another substrate, which in combination with ferric and ferrous ions gives a reddish-pink precipitate. Its sensitivity for staining tissue sections is similar to that of X-gal. Combining X-gal or Salmon-gal with tetrazolium salts provides a faster and more sensitive reaction than traditional β-galactosidase histochemistry. Here, we compare the traditional β-galactosidase assay and the combination of X-gal or Salmon-gal with three tetrazolium salts: nitroblue tetrazolium, tetranitroblue tetrazolium and iodonitrotetrazolium. Based on an assessment of the sensitivity and specificity of the different combinations of substrates, we are proposing an optimized and enhanced method for β-galactosidase detection in histological sections of the transgenic mouse brain. Optimal staining was obtained with X-gal in combination with nitroblue tetrazolium, which provides a faster and more specific staining than the traditional X-gal combination with potassium ferri- and ferro-cyanide. We recommend the X-gal/nitroblue tetrazolium staining mixture as the first choice for the detection of β-galactosidase activity on histological sections. When faster results are needed, Salmon-gal/nitroblue tetrazolium should be considered as an alternative, while maintaining acceptable levels of noise.
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Affiliation(s)
- Stefan Trifonov
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Yuji Yamashita
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Masahiko Kase
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Masato Maruyama
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan
| | - Tetsuo Sugimoto
- Department of Anatomy and Brain Science, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka, 573-1010, Japan.
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84
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CHIBA T, OTANI Y, YAMAGUCHI Y, ISHIBASHI T, HAYASHI A, TANAKA KF, YAMAZAKI M, SAKIMURA K, BABA H. Microglial phospholipase D4 deficiency influences myelination during brain development. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:237-254. [PMID: 27477458 PMCID: PMC5114292 DOI: 10.2183/pjab.92.237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/12/2016] [Indexed: 06/06/2023]
Abstract
Phospholipase D4 (PLD4) is expressed in activated microglia that transiently appear in white matter during postnatal brain development. Previous knockdown experiments using cultured microglia showed PLD4 involvement in phagocytosis and proliferation. To elucidate the role of PLD4 in vivo, PLD4-deficient mice were generated and the cerebella were examined at postnatal day 5 (P5) and P7, when PLD4 expression is highest in microglia. Wild type microglia showed strong immunoreactivity for microglial marker CD68 at P5, whereas CD68 signals were weak in PLD4-deficient microglia, suggesting that loss of PLD4 affects microglial activation. At P5 and P7, immunostaining for anti-myelin basic protein (MBP) antibody indicated a mild but significant delay in myelination in PLD4-deficient cerebellum. Similar change was also observed in the corpus callosum at P7. However, this difference was not apparent at P10, suggesting that microglial PLD4-deficiency primarily influences the early myelination stage. Thus, microglia may have a transient role in myelination via a PLD4-related mechanism during development.
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Affiliation(s)
- Terumasa CHIBA
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Yoshinori OTANI
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Yoshihide YAMAGUCHI
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Tomoko ISHIBASHI
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Akiko HAYASHI
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
| | - Kenji F. TANAKA
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, Japan
| | - Maya YAMAZAKI
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kenji SAKIMURA
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hiroko BABA
- Department of Molecular Neurobiology, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan
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85
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Ageta-Ishihara N, Yamazaki M, Konno K, Nakayama H, Abe M, Hashimoto K, Nishioka T, Kaibuchi K, Hattori S, Miyakawa T, Tanaka K, Huda F, Hirai H, Hashimoto K, Watanabe M, Sakimura K, Kinoshita M. A CDC42EP4/septin-based perisynaptic glial scaffold facilitates glutamate clearance. Nat Commun 2015; 6:10090. [PMID: 26657011 PMCID: PMC4682051 DOI: 10.1038/ncomms10090] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 10/30/2015] [Indexed: 12/31/2022] Open
Abstract
The small GTPase-effector proteins CDC42EP1-5/BORG1–5 interact reciprocally with CDC42 or the septin cytoskeleton. Here we show that, in the cerebellum, CDC42EP4 is exclusively expressed in Bergmann glia and localizes beneath specific membrane domains enwrapping dendritic spines of Purkinje cells. CDC42EP4 forms complexes with septin hetero-oligomers, which interact with a subset of glutamate transporter GLAST/EAAT1. In Cdc42ep4−/− mice, GLAST is dissociated from septins and is delocalized away from the parallel fibre-Purkinje cell synapses. The excitatory postsynaptic current exhibits a protracted decay time constant, reduced sensitivity to a competitive inhibitor of the AMPA-type glutamate receptors (γDGG) and excessive baseline inward current in response to a subthreshold dose of a nonselective inhibitor of the glutamate transporters/EAAT1–5 (DL-TBOA). Insufficient glutamate-buffering/clearance capacity in these mice manifests as motor coordination/learning defects, which are aggravated with subthreshold DL-TBOA. We propose that the CDC42EP4/septin-based glial scaffold facilitates perisynaptic localization of GLAST and optimizes the efficiency of glutamate-buffering and clearance. Glutamate transporters mediate neurotransmitter reuptake at glutamatergic synapses. Here the authors show that CDC42 effector protein CDC42EP4 supports efficient glutamate clearance by promoting the tethering of a glutamate transporter GLAST to perisynaptic clusters of septins in Bergmann glia.
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Affiliation(s)
- Natsumi Ageta-Ishihara
- Division of Biological Sciences, Department of Molecular Biology, Nagoya University Graduate School of Science, Nagoya 464-8602, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kohtarou Konno
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Hisako Nakayama
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kenji Hashimoto
- Division of Clinical Neuroscience, Chiba University Center for Forensic Mental Health, Chiba 260-8670, Japan
| | - Tomoki Nishioka
- Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Showa, Nagoya 466-8560, Japan
| | - Kozo Kaibuchi
- Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Showa, Nagoya 466-8560, Japan
| | - Satoko Hattori
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan
| | - Tsuyoshi Miyakawa
- Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan.,Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Fathul Huda
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Kouichi Hashimoto
- Department of Neurophysiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Makoto Kinoshita
- Division of Biological Sciences, Department of Molecular Biology, Nagoya University Graduate School of Science, Nagoya 464-8602, Japan
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86
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Watanabe-Iida I, Konno K, Akashi K, Abe M, Natsume R, Watanabe M, Sakimura K. Determination of kainate receptor subunit ratios in mouse brain using novel chimeric protein standards. J Neurochem 2015; 136:295-305. [DOI: 10.1111/jnc.13384] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/04/2015] [Accepted: 10/01/2015] [Indexed: 12/01/2022]
Affiliation(s)
- Izumi Watanabe-Iida
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
| | - Kohtarou Konno
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
- Department of Anatomy; Hokkaido University School of Medicine; Sapporo Japan
| | - Kaori Akashi
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
| | - Manabu Abe
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
| | - Rie Natsume
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
| | - Masahiko Watanabe
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
- Department of Anatomy; Hokkaido University School of Medicine; Sapporo Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata Japan
- CREST; Japan Science and Technology Agency; Chiyoda-ku Japan
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87
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Tsukada YI, Akiyama T, Nakayama KI. Maternal TET3 is dispensable for embryonic development but is required for neonatal growth. Sci Rep 2015; 5:15876. [PMID: 26507142 PMCID: PMC4623673 DOI: 10.1038/srep15876] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 10/05/2015] [Indexed: 01/01/2023] Open
Abstract
The development of multicellular organisms is accompanied by reprogramming of the epigenome in specific cells, with the epigenome of most cell types becoming fixed after differentiation. Genome-wide reprogramming of DNA methylation occurs in primordial germ cells and in fertilized eggs during mammalian embryogenesis. The 5-methylcytosine (5mC) content of DNA thus undergoes a marked decrease in the paternal pronucleus of mammalian zygotes. This loss of DNA methylation has been thought to be mediated by an active demethylation mechanism independent of replication and to be required for development. TET3-mediated sequential oxidation of 5mC has recently been shown to contribute to the genome-wide loss of 5mC in the paternal pronucleus of mouse zygotes. We now show that TET3 localizes not only to the paternal pronucleus but also to the maternal pronucleus and oxidizes both paternal and maternal DNA in mouse zygotes, although these phenomena are less pronounced in the female pronucleus. Genetic ablation of TET3 in oocytes had no significant effect on oocyte development, maturation, or fertilization or on pregnancy, but it resulted in neonatal sublethality. Our results thus indicate that zygotic 5mC oxidation mediated by maternal TET3 is required for neonatal growth but is not essential for development.
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Affiliation(s)
- Yu-Ichi Tsukada
- Division of Molecular Immunology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.,Advanced Biological Information Research Division, INAMORI Frontier Research Center, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tomohiko Akiyama
- Department of Systems Medicine, Sakaguchi Laboratory, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8562, Japan
| | - Keiichi I Nakayama
- Division of Cell Regulation Systems, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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88
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Yoshikawa T, Nakajima Y, Yamada Y, Enoki R, Watanabe K, Yamazaki M, Sakimura K, Honma S, Honma KI. Spatiotemporal profiles of arginine vasopressin transcription in cultured suprachiasmatic nucleus. Eur J Neurosci 2015; 42:2678-89. [DOI: 10.1111/ejn.13061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/21/2015] [Accepted: 08/27/2015] [Indexed: 01/18/2023]
Affiliation(s)
- Tomoko Yoshikawa
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Yoshihiro Nakajima
- Health Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Kagawa 761-0395 Japan
| | - Yoshiko Yamada
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ryosuke Enoki
- Photonic Bioimaging Section; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
- Precursory Research for Embryonic Science and Technology (PRESTO); Japan Science and Technology Agency (JST); Saitama 332-0012 Japan
| | - Kazuto Watanabe
- Department of Regulatory Physiology; Dokkyo Medical University School of Medicine; Tochigi 321-0293 Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology; Brain Research Institute; Niigata University; Niigata 951-8585 Japan
| | - Sato Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
| | - Ken-ichi Honma
- Department of Chronomedicine; Hokkaido University Graduate School of Medicine; Sapporo 060-8638 Japan
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89
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Abstract
Intracellular proteins tagged with ubiquitin chains are targeted to the 26S proteasome for degradation. The two subunits, Rpn10 and Rpn13, function as ubiquitin receptors of the proteasome. However, differences in roles between Rpn10 and Rpn13 in mammals remains to be understood. We analyzed mice deficient for Rpn13 and Rpn10. Liver-specific deletion of either Rpn10 or Rpn13 showed only modest impairment, but simultaneous loss of both caused severe liver injury accompanied by massive accumulation of ubiquitin conjugates, which was recovered by re-expression of either Rpn10 or Rpn13. We also found that mHR23B and ubiquilin/Plic-1 and -4 failed to bind to the proteasome in the absence of both Rpn10 and Rpn13, suggesting that these two subunits are the main receptors for these UBL-UBA proteins that deliver ubiquitinated proteins to the proteasome. Our results indicate that Rpn13 mostly plays a redundant role with Rpn10 in recognition of ubiquitinated proteins and maintaining homeostasis in Mus musculus. At least two major ubiquitin receptor subunits that directly capture ubiquitin chains have been identified in the proteasome: Rpn10 and Rpn13. Analyses in Saccharomyces cerevisiae have suggested only a modest role of Rpn10 and Rpn13 in the recruitment of ubiquitinated proteins, as double deletion of Rpn10 and Rpn13 causes very mild phenotypes. Considering that ubiquitin recognition is an essential process for protein degradation by the proteasome and that failure in degradation of ubiquitinated proteins leads to human diseases such as neurodegeneration, it is important to evaluate the role of Rpn10 and Rpn13 in mammals. Liver-specific deletion of either Rpn10 or Rpn13 showed modest impairment, but simultaneous loss of both Rpn10 and Rpn13 caused severe liver injury accompanied by massive accumulation of ubiquitin conjugates and failure in recruiting mHR23B and ubiquilin/Plic-1 and -4 proteins, which deliver ubiquitinated proteins to the proteasome. Our findings indicate that the largely redundant roles of Rpn10 and Rpn13 in ubiquitin recognition and recruitment of mHR23B and ubiquilin/Plic-1 and -4 are essential for cellular homeostasis in mammals and should provide information for understanding the mechanism of ubiquitin recognition by the 26S proteasome in mammals and for development of therapeutic agents targeting protein degradation.
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90
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Iguchi T, Aoki K, Ikawa T, Taoka M, Taya C, Yoshitani H, Toma-Hirano M, Koiwai O, Isobe T, Kawamoto H, Masai H, Miyatake S. BTB-ZF Protein Znf131 Regulates Cell Growth of Developing and Mature T Cells. THE JOURNAL OF IMMUNOLOGY 2015; 195:982-93. [PMID: 26136427 DOI: 10.4049/jimmunol.1500602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/31/2015] [Indexed: 02/01/2023]
Abstract
Many members of the BTB-ZF family have been shown to play important roles in lymphocyte development and function. The role of zinc finger Znf131 (also known as Zbtb35) in T cell lineage was elucidated through the production of mice with floxed allele to disrupt at different stages of development. In this article, we present that Znf131 is critical for T cell development during double-negative to double-positive stage, with which significant cell expansion triggered by the pre-TCR signal is coupled. In mature T cells, Znf131 is required for the activation of effector genes, as well as robust proliferation induced upon TCR signal. One of the cyclin-dependent kinase inhibitors, p21(Cip1) encoded by cdkn1a gene, is one of the targets of Znf131. The regulation of T cell proliferation by Znf131 is in part attributed to its suppression on the expression of p21(Cip1).
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Affiliation(s)
- Tomohiro Iguchi
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Kazuhisa Aoki
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tomokatsu Ikawa
- Young Chief Investigators Laboratory for Immune Regeneration, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Masato Taoka
- Laboratory of Biochemistry, Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Choji Taya
- Animal Research Division, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Hiroshi Yoshitani
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Makiko Toma-Hirano
- Department of Otolaryngology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Osamu Koiwai
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Toshiaki Isobe
- Laboratory of Biochemistry, Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Hiroshi Kawamoto
- Department of Immunology, Field of Regeneration Control, Institute of Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; and
| | - Hisao Masai
- Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Shoichiro Miyatake
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan;
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91
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Transient expression of neuropeptide W in postnatal mouse hypothalamus--a putative regulator of energy homeostasis. Neuroscience 2015; 301:323-37. [PMID: 26073698 DOI: 10.1016/j.neuroscience.2015.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/29/2015] [Accepted: 06/06/2015] [Indexed: 11/24/2022]
Abstract
Neuropeptide B and W (NPB and NPW) are cognate peptide ligands for NPBWR1 (GPR7), a G protein-coupled receptor. In rodents, they have been implicated in the regulation of energy homeostasis, neuroendocrine/autonomic responses, and social interactions. Although localization of these peptides and their receptors in adult rodent brain has been well documented, their expression in mouse brain during development is unknown. Here we demonstrate the transient expression of NPW mRNA in the dorsomedial hypothalamus (DMH) of postnatal mouse brain and its co-localization with neuropeptide Y (NPY) mRNA. Neurons expressing both NPW and NPY mRNAs begin to emerge in the DMH at about postnatal day 0 (P-0) through P-3. Their expression is highest around P-14, declines after P-21, and by P-28 only a faint expression of NPW and NPY mRNA remains. In P-18 brains, we detected NPW neurons in the region spanning the subincertal nucleus (SubI), the lateral hypothalamic (LH) perifornical (PF) areas, and the DMH, where the highest expression of NPW mRNA was observed. The majority of these postnatal hypothalamic NPW neurons co-express NPY mRNA. A cross of NPW-iCre knock-in mice with a Cre-dependent tdTomato reporter line revealed that more than half of the reporter-positive neurons in the adult DMH, which mature from the transiently NPW-expressing neurons, are sensitive to peripherally administrated leptin. These data suggest that the DMH neurons that transiently co-express NPW and NPY in the peri-weaning period might play a role in regulating energy homeostasis during postnatal development.
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92
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Kishimoto Y, Cagniard B, Yamazaki M, Nakayama J, Sakimura K, Kirino Y, Kano M. Task-specific enhancement of hippocampus-dependent learning in mice deficient in monoacylglycerol lipase, the major hydrolyzing enzyme of the endocannabinoid 2-arachidonoylglycerol. Front Behav Neurosci 2015; 9:134. [PMID: 26082696 PMCID: PMC4451424 DOI: 10.3389/fnbeh.2015.00134] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/11/2015] [Indexed: 12/03/2022] Open
Abstract
Growing evidence indicates that the endocannabinoid system is important for the acquisition and/or extinction of learning and memory. However, it is unclear which endocannabinoid(s) play(s) a crucial role in these cognitive functions, especially memory extinction. To elucidate the physiological role of 2-arachidonoylglycerol (2-AG), a major endocannabinoid, in behavioral and cognitive functions, we conducted a comprehensive behavioral test battery in knockout (KO) mice deficient in monoacylglycerol lipase (MGL), the major hydrolyzing enzyme of 2-AG. We found age-dependent increases in spontaneous physical activity (SPA) in MGL KO mice. Next, we tested the MGL KO mice using 5 hippocampus-dependent learning paradigms (i.e., Morris water maze (MWM), contextual fear conditioning, novel object recognition test, trace eyeblink conditioning, and water-finding test). In the MWM, MGL KO mice showed normal acquisition of reference memory, but exhibited significantly faster extinction of the learned behavior. Moreover, they showed faster memory acquisition on the reversal-learning task of the MWM. In contrast, in the contextual fear conditioning, MGL KO mice tended to show slower memory extinction. In the novel object recognition and water-finding tests, MGL KO mice exhibited enhanced memory acquisition. Trace eyeblink conditioning was not altered in MGL KO mice throughout the acquisition and extinction phases. These results indicate that 2-AG signaling is important for hippocampus-dependent learning and memory, but its contribution is highly task-dependent.
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Affiliation(s)
- Yasushi Kishimoto
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Barbara Cagniard
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo Bunkyo-ku, Tokyo, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University Niigata, Japan
| | - Junko Nakayama
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University Niigata, Japan
| | - Yutaka Kirino
- Laboratory of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University Sanuki, Kagawa, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo Bunkyo-ku, Tokyo, Japan
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93
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Suzuki J, Sakurai K, Yamazaki M, Abe M, Inada H, Sakimura K, Katori Y, Osumi N. Horizontal Basal Cell-Specific Deletion of Pax6 Impedes Recovery of the Olfactory Neuroepithelium Following Severe Injury. Stem Cells Dev 2015; 24:1923-33. [PMID: 25808240 DOI: 10.1089/scd.2015.0011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In the mammalian olfactory epithelium (OE), olfactory receptor neurons (ORNs) are continuously regenerated throughout the animal's lifetime. Horizontal basal cells (HBCs) in the OE express the epithelial marker keratin 5 (K5) and the stem cell marker Pax6 and are considered relatively quiescent tissue stem cells in the OE. Pax6 is a key regulator of several developmental processes in the central nervous system and in sensory organs. Although Pax6 is expressed in the OE, its precise role remains unknown, particularly with respect to stem cell-like HBCs. To investigate the function of Pax6 in the developmental and regenerative processes in the OE, we generated conditional Pax6-knockout mice carrying a loxP-floxed Pax6 gene. Homozygous Pax6-floxed mice were crossed with K5-Cre transgenic mice to generate HBC-specific Pax6-knockout (Pax6-cKO) mice. We confirmed that the deletion of Pax6 expression in HBCs was sufficiently achieved in zone 1 of the OE in Pax6-cKO mice 3 days after methimazole-induced severe damage. In this condition, regeneration of the OE was dramatically impaired; both OE thickness and the number of ORNs were significantly decreased in the regenerated OE of Pax6-cKO mice. These results suggest that Pax6 expression is essential for HBCs to differentiate into neuronal cells during the regeneration process following severe injury.
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Affiliation(s)
- Jun Suzuki
- 1 Department of Developmental Neuroscience, Centers for Neuroscience, Tohoku University Graduate School of Medicine , Sendai, Miyagi, Japan .,2 Department of Otorhinolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine , Sendai, Miyagi, Japan
| | - Katsuyasu Sakurai
- 3 Department of Neurobiology, Duke University Medical Center , Durham, North Carolina
| | - Maya Yamazaki
- 4 Department of Cellular Neurobiology, Brain Research Institute, Niigata University , Niigata, Japan
| | - Manabu Abe
- 4 Department of Cellular Neurobiology, Brain Research Institute, Niigata University , Niigata, Japan
| | - Hitoshi Inada
- 1 Department of Developmental Neuroscience, Centers for Neuroscience, Tohoku University Graduate School of Medicine , Sendai, Miyagi, Japan
| | - Kenji Sakimura
- 4 Department of Cellular Neurobiology, Brain Research Institute, Niigata University , Niigata, Japan
| | - Yukio Katori
- 2 Department of Otorhinolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine , Sendai, Miyagi, Japan
| | - Noriko Osumi
- 1 Department of Developmental Neuroscience, Centers for Neuroscience, Tohoku University Graduate School of Medicine , Sendai, Miyagi, Japan
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94
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Structure-function relationships between aldolase C/zebrin II expression and complex spike synchrony in the cerebellum. J Neurosci 2015; 35:843-52. [PMID: 25589776 DOI: 10.1523/jneurosci.2170-14.2015] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Simple and regular anatomical structure is a hallmark of the cerebellar cortex. Parasagittally arrayed alternate expression of aldolase C/zebrin II in Purkinje cells (PCs) has been extensively studied, but surprisingly little is known about its functional significance. Here we found a precise structure-function relationship between aldolase C expression and synchrony of PC complex spike activities that reflect climbing fiber inputs to PCs. We performed two-photon calcium imaging in transgenic mice in which aldolase C compartments can be visualized in vivo, and identified highly synchronous complex spike activities among aldolase C-positive or aldolase C-negative PCs, but not across these populations. The boundary of aldolase C compartments corresponded to that of complex spike synchrony at single-cell resolution. Sensory stimulation evoked aldolase C compartment-specific complex spike responses and synchrony. This result further revealed the structure-function segregation. In awake animals, complex spike synchrony both within and between PC populations across the aldolase C boundary were enhanced in response to sensory stimuli, in a way that two functionally distinct PC ensembles are coactivated. These results suggest that PC populations characterized by aldolase C expression precisely represent distinct functional units of the cerebellar cortex, and these functional units can cooperate to process sensory information in awake animals.
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95
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Van B, Nishi M, Komazaki S, Ichimura A, Kakizawa S, Nakanaga K, Aoki J, Park KH, Ma J, Ueyama T, Ogata T, Maruyama N, Takeshima H. Mitsugumin 56 (hedgehog acyltransferase-like) is a sarcoplasmic reticulum-resident protein essential for postnatal muscle maturation. FEBS Lett 2015; 589:1095-104. [DOI: 10.1016/j.febslet.2015.03.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 02/02/2023]
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96
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Saito S, Kawamura T, Higuchi M, Kobayashi T, Yoshita-Takahashi M, Yamazaki M, Abe M, Sakimura K, Kanda Y, Kawamura H, Jiang S, Naito M, Yoshizaki T, Takahashi M, Fujii M. RASAL3, a novel hematopoietic RasGAP protein, regulates the number and functions of NKT cells. Eur J Immunol 2015; 45:1512-23. [PMID: 25652366 DOI: 10.1002/eji.201444977] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 01/12/2015] [Accepted: 01/29/2015] [Indexed: 01/30/2023]
Abstract
Ras GTPase-activating proteins negatively regulate the Ras/Erk signaling pathway, thereby playing crucial roles in the proliferation, function, and development of various types of cells. In this study, we identified a novel Ras GTPase-activating proteins protein, RASAL3, which is predominantly expressed in cells of hematopoietic lineages, including NKT, B, and T cells. We established systemic RASAL3-deficient mice, and the mice exhibited a severe decrease in NKT cells in the liver at 8 weeks of age. The treatment of RASAL3-deficient mice with α-GalCer, a specific agonist for NKT cells, induced liver damage, but the level was less severe than that in RASAL3-competent mice, and the attenuated liver damage was accompanied by a reduced production of interleukin-4 and interferon-γ from NKT cells. RASAL3-deficient NKT cells treated with α-GalCer in vitro presented augmented Erk phosphorylation, suggesting that there is dysregulated Ras signaling in the NKT cells of RASAL3-deficient mice. Taken together, these results suggest that RASAL3 plays an important role in the expansion and functions of NKT cells in the liver by negatively regulating Ras/Erk signaling, and might be a therapeutic target for NKT-associated diseases.
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Affiliation(s)
- Suguru Saito
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Toshihiko Kawamura
- Division of Immunology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Masaya Higuchi
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Takahiro Kobayashi
- Division of Immunology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Manami Yoshita-Takahashi
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.,Center for Fostering Innovative Leadership, Niigata University, Niigata, Japan
| | - Maya Yamazaki
- Division of Neurocellular Biology, Brain Research Center, Niigata University, Niigata, Japan
| | - Manabu Abe
- Division of Neurocellular Biology, Brain Research Center, Niigata University, Niigata, Japan
| | - Kenji Sakimura
- Division of Neurocellular Biology, Brain Research Center, Niigata University, Niigata, Japan
| | - Yasuhiro Kanda
- Division of Immunology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Hiroki Kawamura
- Department of Clinical Engineering and Medical Technology, Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan
| | - Shuying Jiang
- Division of Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.,Niigata College of Medical Technology, Niigata, Japan
| | - Makoto Naito
- Division of Pathology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Takumi Yoshizaki
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Masahiko Takahashi
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Masahiro Fujii
- Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
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97
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Yasumura M, Yoshida T, Yamazaki M, Abe M, Natsume R, Kanno K, Uemura T, Takao K, Sakimura K, Kikusui T, Miyakawa T, Mishina M. IL1RAPL1 knockout mice show spine density decrease, learning deficiency, hyperactivity and reduced anxiety-like behaviours. Sci Rep 2014; 4:6613. [PMID: 25312502 PMCID: PMC4196104 DOI: 10.1038/srep06613] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 09/23/2014] [Indexed: 12/14/2022] Open
Abstract
IL-1 receptor accessory protein-like 1 (IL1RAPL1) is responsible for nonsyndromic intellectual disability and is associated with autism. IL1RAPL1 mediates excitatory synapse formation through trans-synaptic interaction with PTPδ. Here, we showed that the spine density of cortical neurons was significantly reduced in IL1RAPL1 knockout mice. The spatial reference and working memories and remote fear memory were mildly impaired in IL1RAPL1 knockout mice. Furthermore, the behavioural flexibility was slightly reduced in the T-maze test. Interestingly, the performance of IL1RAPL1 knockout mice in the rotarod test was significantly better than that of wild-type mice. Moreover, IL1RAPL1 knockout mice consistently exhibited high locomotor activity in all the tasks examined. In addition, open-space and height anxiety-like behaviours were decreased in IL1RAPL1 knockout mice. These results suggest that IL1RAPL1 ablation resulted in spine density decrease and affected not only learning but also behavioural flexibility, locomotor activity and anxiety.
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Affiliation(s)
- Misato Yasumura
- 1] Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan [2] Liaison Academy, School of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan
| | - Tomoyuki Yoshida
- 1] Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan [2] Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Toyama, Japan [3] PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Maya Yamazaki
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Manabu Abe
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Rie Natsume
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Kouta Kanno
- Companion Animal Research, School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
| | - Takeshi Uemura
- 1] Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan [2] Department of Molecular and Cellular Physiology, Shinsyu University School of Medicine, Matsumoto, Nagano, Japan
| | - Keizo Takao
- Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physical Sciences, Okazaki, Aichi, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Takefumi Kikusui
- Companion Animal Research, School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan
| | - Tsuyoshi Miyakawa
- 1] Section of Behavior Patterns, Center for Genetic Analysis of Behavior, National Institute for Physical Sciences, Okazaki, Aichi, Japan [2] Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Masayoshi Mishina
- 1] Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan [2] Brain Science Laboratory, The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan
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98
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Is D-aspartate produced by glutamic-oxaloacetic transaminase-1 like 1 (Got1l1): a putative aspartate racemase? Amino Acids 2014; 47:79-86. [PMID: 25287256 PMCID: PMC4282708 DOI: 10.1007/s00726-014-1847-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/25/2014] [Indexed: 12/23/2022]
Abstract
D-Aspartate is an endogenous free amino acid in the brain, endocrine tissues, and exocrine tissues in mammals, and it plays several physiological roles. In the testis, D-aspartate is detected in elongate spermatids, Leydig cells, and Sertoli cells, and implicated in the synthesis and release of testosterone. In the hippocampus, D-aspartate strongly enhances N-methyl-D-aspartate receptor-dependent long-term potentiation and is involved in learning and memory. The existence of aspartate racemase, a candidate enzyme for D-aspartate production, has been suggested. Recently, mouse glutamic-oxaloacetic transaminase 1-like 1 (Got1l1) has been reported to synthesize substantially D-aspartate from L-aspartate and to be involved in adult neurogenesis. In this study, we investigated the function of Got1l1 in vivo by generating and analyzing Got1l1 knockout (KO) mice. We also examined the enzymatic activity of recombinant Got1l1 in vitro. We found that Got1l1 mRNA is highly expressed in the testis, but it is not detected in the brain and submandibular gland, where D-aspartate is abundant. The D-aspartate contents of wild-type and Got1l1 KO mice were not significantly different in the testis and hippocampus. The recombinant Got1l1 expressed in mammalian cells showed L-aspartate aminotransferase activity, but lacked aspartate racemase activity. These findings suggest that Got1l1 is not the major aspartate racemase and there might be an as yet unknown D-aspartate-synthesizing enzyme.
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99
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Itoi K, Talukder AH, Fuse T, Kaneko T, Ozawa R, Sato T, Sugaya T, Uchida K, Yamazaki M, Abe M, Natsume R, Sakimura K. Visualization of corticotropin-releasing factor neurons by fluorescent proteins in the mouse brain and characterization of labeled neurons in the paraventricular nucleus of the hypothalamus. Endocrinology 2014; 155:4054-60. [PMID: 25057791 DOI: 10.1210/en.2014-1182] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Corticotropin-releasing factor (CRF) is the key regulator of the hypothalamic-pituitary-adrenal axis. CRF neurons cannot be distinguished morphologically from other neuroendocrine neurons in the paraventricular nucleus of the hypothalamus (PVH) without immunostaining. Thus, we generated a knock-in mouse that expresses modified yellow fluorescent protein (Venus) in CRF neurons (CRF-Venus), and yet its expression is driven by the CRF promoter and responds to changes in the interior milieu. In CRF-Venus, Venus-expressing neurons were distributed in brain regions harboring CRF neurons, including the PVH. The majority of Venus-expressing neurons overlapped with CRF-expressing neurons in the PVH, but many neurons expressed only Venus or CRF in a physiological glucocorticoid condition. After glucocorticoid deprivation, however, Venus expression intensified, and most Venus neurons coexpressed CRF. Conversely, Venus expression was suppressed by excess glucocorticoids. Expression of copeptin, a peptide encoded within the vasopressin gene, was induced in PVH-Venus neurons by glucocorticoid deprivation and suppressed by glucocorticoid administration. Thus, Venus neurons recapitulated glucocorticoid-dependent vasopressin expression in PVH-CRF neurons. Noradrenaline increased the frequency of glutamate-dependent excitatory postsynaptic currents recorded from Venus-expressing neurons in the voltage clamp mode. In addition, the CRF-iCre knock-in mouse was crossed with a CAG-CAT-EGFP reporter mouse to yield the Tg(CAG-CAT-EGFP/wt);CRF(iCre/wt) (EGFP/CRF-iCre) mouse, in which enhanced green fluorescent protein (EGFP) is driven by the CAG promoter. EGFP was expressed more constitutively in the PVH of EGFP/CRF-iCre mice. Thus, CRF-Venus may have an advantage for monitoring dynamic changes in CRF neurons and CRF networks in different glucocorticoid states.
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Affiliation(s)
- Keiichi Itoi
- Laboratory of Information Biology (K.I., A.H.T., T.F., T.K., R.O., T.Sa., T.Su., K.U.), Graduate School of Information Sciences, Tohoku University, Sendai 980-8579, Japan; Department of Neuroendocrinology (K.I.), Graduate School of Medicine, Tohoku University, Sendai 980-8579, Japan; and Department of Cellular Neurobiology (M.Y., M.A., R.N., K.S.), Brain Research Institute, Niigata University, Niigata 951-8585, Japan
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100
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Expansion of stochastic expression repertoire by tandem duplication in mouse Protocadherin-α cluster. Sci Rep 2014; 4:6263. [PMID: 25179445 PMCID: PMC4151104 DOI: 10.1038/srep06263] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/13/2014] [Indexed: 11/08/2022] Open
Abstract
Tandem duplications are concentrated within the Pcdh cluster throughout vertebrate evolution and as copy number variations (CNVs) in human populations, but the effects of tandem duplication in the Pcdh cluster remain elusive. To investigate the effects of tandem duplication in the Pcdh cluster, here we generated and analyzed a new line of the Pcdh cluster mutant mice. In the mutant allele, a 218-kb region containing the Pcdh-α2 to Pcdh-αc2 variable exons with their promoters was duplicated and the individual duplicated Pcdh isoforms can be disctinguished. The individual duplicated Pcdh-α isoforms showed diverse expression level with stochastic expression manner, even though those have an identical promoter sequence. Interestingly, the 5'-located duplicated Pcdh-αc2, which is constitutively expressed in the wild-type brain, shifted to stochastic expression accompanied by increased DNA methylation. These results demonstrate that tandem duplication in the Pcdh cluster expands the stochastic expression repertoire irrespective of sequence divergence.
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