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Takenaka M, Kodama M, Murayama T, Ishigami-Yuasa M, Mori S, Ishida R, Suzuki J, Kanemaru K, Sugihara M, Iino M, Miura A, Nishio H, Morimoto S, Kagechika H, Sakurai T, Kurebayashi N. Screening for Novel Type 2 Ryanodine Receptor Inhibitors by Endoplasmic Reticulum Ca 2+ Monitoring. Mol Pharmacol 2023; 104:275-286. [PMID: 37678938 DOI: 10.1124/molpharm.123.000720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/21/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023] Open
Abstract
Type 2 ryanodine receptor (RyR2) is a Ca2+ release channel on the endoplasmic (ER)/sarcoplasmic reticulum that plays a central role in the excitation-contraction coupling in the heart. Hyperactivity of RyR2 has been linked to ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia and heart failure, where spontaneous Ca2+ release via hyperactivated RyR2 depolarizes diastolic membrane potential to induce triggered activity. In such cases, drugs that suppress RyR2 activity are expected to prevent the arrhythmias, but there is no clinically available RyR2 inhibitors at present. In this study, we searched for RyR2 inhibitors from a well-characterized compound library using a recently developed ER Ca2+-based assay, where the inhibition of RyR2 activity was detected by the increase in ER Ca2+ signals from R-CEPIA1er, a genetically encoded ER Ca2+ indicator, in RyR2-expressing HEK293 cells. By screening 1535 compounds in the library, we identified three compounds (chloroxylenol, methyl orsellinate, and riluzole) that greatly increased the ER Ca2+ signal. All of the three compounds suppressed spontaneous Ca2+ oscillations in RyR2-expressing HEK293 cells and correspondingly reduced the Ca2+-dependent [3H]ryanodine binding activity. In cardiomyocytes from RyR2-mutant mice, the three compounds effectively suppressed abnormal Ca2+ waves without substantial effects on the action-potential-induced Ca2+ transients. These results confirm that ER Ca2+-based screening is useful for identifying modulators of ER Ca2+ release channels and suggest that RyR2 inhibitors have potential to be developed as a new category of antiarrhythmic drugs. SIGNIFICANCE STATEMENT: We successfully identified three compounds having RyR2 inhibitory action from a well-characterized compound library using an endoplasmic reticulum Ca2+-based assay, and demonstrated that these compounds suppressed arrhythmogenic Ca2+ wave generation without substantially affecting physiological action-potential induced Ca2+ transients in cardiomyocytes. This study will facilitate the development of RyR2-specific inhibitors as a potential new class of drugs for life-threatening arrhythmias induced by hyperactivation of RyR2.
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Affiliation(s)
- Mai Takenaka
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masami Kodama
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Mari Ishigami-Yuasa
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Shuichi Mori
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Ryosuke Ishida
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Junji Suzuki
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Kazunori Kanemaru
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masami Sugihara
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masamitsu Iino
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Aya Miura
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Hajime Nishio
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Sachio Morimoto
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Hiroyuki Kagechika
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
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2
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Zampese E, Wokosin DL, Gonzalez-Rodriguez P, Guzman JN, Tkatch T, Kondapalli J, Surmeier WC, D’Alessandro KB, De Stefani D, Rizzuto R, Iino M, Molkentin JD, Chandel NS, Schumacker PT, Surmeier DJ. Ca 2+ channels couple spiking to mitochondrial metabolism in substantia nigra dopaminergic neurons. Sci Adv 2022; 8:eabp8701. [PMID: 36179023 PMCID: PMC9524841 DOI: 10.1126/sciadv.abp8701] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/12/2022] [Indexed: 05/08/2023]
Abstract
How do neurons match generation of adenosine triphosphate by mitochondria to the bioenergetic demands of regenerative activity? Although the subject of speculation, this coupling is still poorly understood, particularly in neurons that are tonically active. To help fill this gap, pacemaking substantia nigra dopaminergic neurons were studied using a combination of optical, electrophysiological, and molecular approaches. In these neurons, spike-activated calcium (Ca2+) entry through Cav1 channels triggered Ca2+ release from the endoplasmic reticulum, which stimulated mitochondrial oxidative phosphorylation through two complementary Ca2+-dependent mechanisms: one mediated by the mitochondrial uniporter and another by the malate-aspartate shuttle. Disrupting either mechanism impaired the ability of dopaminergic neurons to sustain spike activity. While this feedforward control helps dopaminergic neurons meet the bioenergetic demands associated with sustained spiking, it is also responsible for their elevated oxidant stress and possibly to their decline with aging and disease.
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Affiliation(s)
- Enrico Zampese
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - David L. Wokosin
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Patricia Gonzalez-Rodriguez
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Jaime N. Guzman
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Tatiana Tkatch
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Jyothisri Kondapalli
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - William C. Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
| | - Karis B. D’Alessandro
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova 35131, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova 35131, Italy
| | - Masamitsu Iino
- Department of Physiology, Nihon University School of Medicine, 30-1, Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan
| | - Jeffery D. Molkentin
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Navdeep S. Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Paul T. Schumacker
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - D. James Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA
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Kurebayashi N, Murayama T, Ota R, Suzuki J, Kanemaru K, Kobayashi T, Ohno S, Horie M, Iino M, Yamashita F, Sakurai T. Cytosolic Ca2+-dependent Ca2+ release activity primarily determines the ER Ca2+ level in cells expressing the CPVT-linked mutant RYR2. J Gen Physiol 2022; 154:213175. [PMID: 35446340 PMCID: PMC9037340 DOI: 10.1085/jgp.202112869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 11/28/2021] [Accepted: 04/04/2022] [Indexed: 12/16/2022] Open
Abstract
Type 2 ryanodine receptor (RYR2) is a cardiac Ca2+ release channel in the ER. Mutations in RYR2 are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is associated with enhanced spontaneous Ca2+ release, which tends to occur when [Ca2+]ER reaches a threshold. Mutations lower the threshold [Ca2+]ER by increasing luminal Ca2+ sensitivity or enhancing cytosolic [Ca2+] ([Ca2+]cyt)-dependent activity. Here, to establish the mechanism relating the change in [Ca2+]cyt-dependent activity of RYR2 and the threshold [Ca2+]ER, we carried out cell-based experiments and in silico simulations. We expressed WT and CPVT-linked mutant RYR2s in HEK293 cells and measured [Ca2+]cyt and [Ca2+]ER using fluorescent Ca2+ indicators. CPVT RYR2 cells showed higher oscillation frequency and lower threshold [Ca2+]ER than WT cells. The [Ca2+]cyt-dependent activity at resting [Ca2+]cyt, Arest, was greater in CPVT mutants than in WT, and we found an inverse correlation between threshold [Ca2+]ER and Arest. In addition, lowering RYR2 expression increased the threshold [Ca2+]ER and a product of Arest, and the relative expression level for each mutant correlated with threshold [Ca2+]ER, suggesting that the threshold [Ca2+]ER depends on the net Ca2+ release rate via RYR2. Modeling reproduced Ca2+ oscillations with [Ca2+]cyt and [Ca2+]ER changes in WT and CPVT cells. Interestingly, the [Ca2+]cyt-dependent activity of specific mutations correlated with the age of disease onset in patients carrying them. Our data suggest that the reduction in threshold [Ca2+]ER for spontaneous Ca2+ release by CPVT mutation is explained by enhanced [Ca2+]cyt-dependent activity without requiring modulation of the [Ca2+]ER sensitivity of RYR2.
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Affiliation(s)
- Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan,Correspondence to Nagomi Kurebayashi:
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Ryosaku Ota
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Junji Suzuki
- Department of Physiology, University of California San Francisco, San Francisco, CA
| | - Kazunori Kanemaru
- Department of Physiology, Nihon University School of Medicine, Tokyo, Japan
| | - Takuya Kobayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Minoru Horie
- Department of Cardiovascular Medicine, Shiga University of Medical Science, Shiga, Japan
| | - Masamitsu Iino
- Department of Physiology, Nihon University School of Medicine, Tokyo, Japan
| | - Fumiyoshi Yamashita
- Department of Drug Delivery Research, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan,Fumiyoshi Yamashita:
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Kitajima N, Takikawa K, Sekiya H, Asanuma D, Sakamoto H, Namiki S, Iino M, Hirose K. In vivo Fluorescence Imaging of Extracellular ATP in the Mouse Cerebral Cortex with a Hybrid-type Optical Sensor. Bio Protoc 2021; 11:e4046. [PMID: 34250212 DOI: 10.21769/bioprotoc.4046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/16/2021] [Accepted: 04/25/2021] [Indexed: 12/26/2022] Open
Abstract
Adenosine 5'-triphosphate (ATP) works as an extracellular signaling molecule for cells in the brain, such as neurons and glia. Cellular communication via release of ATP is involved in a range of processes required for normal brain functions, and aberrant communication is associated with brain disorders. To investigate the mechanisms underlying these cellular processes, various techniques have been developed for the measurement of extracellular ATP. To monitor the dynamics of extracellular ATP signaling with high spatiotemporal resolution, we recently developed a hybrid-type ATP optical sensor (ATPOS) that enables in vivo fluorescence imaging of extracellular ATP dynamics in the brain. ATPOS is synthesized by labeling an ATP-binding protein, Bacillus FoF1-ATP synthase ε subunit, with a small-molecular fluorescent dye Cy3. Injection of ATPOS into the cerebral cortex of living mice enables visualization of the wave-like propagation of extracellular ATP release in response to electrical stimulation. The protocol described here should be useful for visualizing ATP signaling in diverse processes involved in intercellular communication in the brain.
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Affiliation(s)
- Nami Kitajima
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kenji Takikawa
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Sekiya
- Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Daisuke Asanuma
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Sakamoto
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shigeyuki Namiki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masamitsu Iino
- Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence, The University of Tokyo, Tokyo, Japan
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5
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Escartin C, Galea E, Lakatos A, O'Callaghan JP, Petzold GC, Serrano-Pozo A, Steinhäuser C, Volterra A, Carmignoto G, Agarwal A, Allen NJ, Araque A, Barbeito L, Barzilai A, Bergles DE, Bonvento G, Butt AM, Chen WT, Cohen-Salmon M, Cunningham C, Deneen B, De Strooper B, Díaz-Castro B, Farina C, Freeman M, Gallo V, Goldman JE, Goldman SA, Götz M, Gutiérrez A, Haydon PG, Heiland DH, Hol EM, Holt MG, Iino M, Kastanenka KV, Kettenmann H, Khakh BS, Koizumi S, Lee CJ, Liddelow SA, MacVicar BA, Magistretti P, Messing A, Mishra A, Molofsky AV, Murai KK, Norris CM, Okada S, Oliet SHR, Oliveira JF, Panatier A, Parpura V, Pekna M, Pekny M, Pellerin L, Perea G, Pérez-Nievas BG, Pfrieger FW, Poskanzer KE, Quintana FJ, Ransohoff RM, Riquelme-Perez M, Robel S, Rose CR, Rothstein JD, Rouach N, Rowitch DH, Semyanov A, Sirko S, Sontheimer H, Swanson RA, Vitorica J, Wanner IB, Wood LB, Wu J, Zheng B, Zimmer ER, Zorec R, Sofroniew MV, Verkhratsky A. Reactive astrocyte nomenclature, definitions, and future directions. Nat Neurosci 2021; 24:312-325. [PMID: 33589835 PMCID: PMC8007081 DOI: 10.1038/s41593-020-00783-4] [Citation(s) in RCA: 961] [Impact Index Per Article: 320.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022]
Abstract
Reactive astrocytes are astrocytes undergoing morphological, molecular, and functional remodeling in response to injury, disease, or infection of the CNS. Although this remodeling was first described over a century ago, uncertainties and controversies remain regarding the contribution of reactive astrocytes to CNS diseases, repair, and aging. It is also unclear whether fixed categories of reactive astrocytes exist and, if so, how to identify them. We point out the shortcomings of binary divisions of reactive astrocytes into good-vs-bad, neurotoxic-vs-neuroprotective or A1-vs-A2. We advocate, instead, that research on reactive astrocytes include assessment of multiple molecular and functional parameters-preferably in vivo-plus multivariate statistics and determination of impact on pathological hallmarks in relevant models. These guidelines may spur the discovery of astrocyte-based biomarkers as well as astrocyte-targeting therapies that abrogate detrimental actions of reactive astrocytes, potentiate their neuro- and glioprotective actions, and restore or augment their homeostatic, modulatory, and defensive functions.
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Affiliation(s)
- Carole Escartin
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France.
| | - Elena Galea
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - András Lakatos
- John van Geest Centre for Brain Repair and Division of Stem Cell Neurobiology, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Cambridge, UK
| | - James P O'Callaghan
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Division of Vascular Neurology, Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Alberto Serrano-Pozo
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andrea Volterra
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Giorgio Carmignoto
- Neuroscience Institute, Italian National Research Council (CNR), Padua, Italy
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Amit Agarwal
- The Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, La Jolla, California, USA
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Ramat Aviv Tel Aviv, Israel
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Gilles Bonvento
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| | - Arthur M Butt
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK
| | - Wei-Ting Chen
- Center for Brain and Disease Research, VIB and University of Leuven, Leuven, Belgium
| | - Martine Cohen-Salmon
- 'Physiology and Physiopathology of the Gliovascular Unit' Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Unité Mixte de Recherche 7241 CNRS, Unité1050 INSERM, PSL Research University, Paris, France
| | - Colm Cunningham
- Trinity Biomedical Sciences Institute & Trinity College Institute of Neuroscience, School of Biochemistry & Immunology, Trinity College Dublin, Dublin, Republic of Ireland
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Bart De Strooper
- Center for Brain and Disease Research, VIB and University of Leuven, Leuven, Belgium
- UK Dementia Research Institute at the University College London, London, UK
| | - Blanca Díaz-Castro
- UK Dementia Research Institute at the University of Edinburgh, Centre for Discovery Brain Sciences, Edinburgh, UK
| | - Cinthia Farina
- Institute of Experimental Neurology (INSpe) and Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington DC, USA
| | - James E Goldman
- Department of Pathology & Cell Biology, Columbia University, New York, New York, USA
| | - Steven A Goldman
- University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Science and Rigshospitalet, Kobenhavn N, Denmark
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-Universitaet & Institute of Stem Cell Research, Helmholtz Center Munich, Munich, Germany
- Synergy, Excellence Cluster of Systems Neurology, Biomedical Center, Munich, Germany
| | - Antonia Gutiérrez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Dieter H Heiland
- Microenvironment and Immunology Research Laboratory, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Matthew G Holt
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
| | - Ksenia V Kastanenka
- Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Helmut Kettenmann
- Cellular Neurosciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science 55, Expo-ro, Yuseong-gu, Daejeon, Korea
| | - Shane A Liddelow
- Neuroscience Institute, Department of Neuroscience and Physiology, Department of Ophthalmology, NYU School of Medicine, New York, USA
| | - Brian A MacVicar
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pierre Magistretti
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Centre de Neurosciences Psychiatriques, University of Lausanne and CHUV, Site de Cery, Prilly-Lausanne, Lausanne, Switzerland
| | - Albee Messing
- Waisman Center and School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Anusha Mishra
- Department of Neurology Jungers Center for Neurosciences Research and Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Anna V Molofsky
- Departments of Psychiatry/Weill Institute for Neuroscience University of California, San Francisco, California, USA
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology & Neurosurgery, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Seiji Okada
- Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Stéphane H R Oliet
- Université de Bordeaux, Inserm, Neurocentre Magendie, U1215, Bordeaux, France
| | - João F Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's -PT Government Associate Laboratory, Braga/Guimarães, Portugal
- IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence Laboratory, Campus of IPCA, Barcelos, Portugal
| | - Aude Panatier
- Université de Bordeaux, Inserm, Neurocentre Magendie, U1215, Bordeaux, France
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Marcela Pekna
- Laboratory of Regenerative Neuroimmunology, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Milos Pekny
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Luc Pellerin
- INSERM U1082, Université de Poitiers, Poitiers, France
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Cajal Institute, CSIC, Madrid, Spain
| | - Beatriz G Pérez-Nievas
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Frank W Pfrieger
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California, USA
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School. Associate Member, The Broad Institute, Boston, Massachusetts, USA
| | | | - Miriam Riquelme-Perez
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| | - Stefanie Robel
- Fralin Biomedical Research Institute at Virginia Tech Carilion, School of Neuroscience Virginia Tech, Riverside Circle, Roanoke, Virginia, USA
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University, Düsseldorf, Germany
| | - Jeffrey D Rothstein
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University Paris, Paris, France
| | - David H Rowitch
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Cambridge, UK
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, LMU Munich, Munich, Germany
- Institute for Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany
| | - Harald Sontheimer
- Virginia Tech School of Neuroscience and Center for Glial Biology in Health, Disease and Cancer, Virginia Tech at the Fralin Biomedical Research Institute, Roanoke, Virginia, USA
| | - Raymond A Swanson
- Dept. of Neurology, University of California San Francisco and San Francisco Veterans Affairs Health Care System, San Francisco, California, USA
| | - Javier Vitorica
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Dept. Bioquímica y Biología Molecular, Instituto de Biomedicina de Sevilla, Universidad de Sevilla, Hospital Virgen del Rocío/CSIC, Sevilla, Spain
| | - Ina-Beate Wanner
- Semel Institute for Neuroscience & Human Behavior, IDDRC, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Levi B Wood
- George W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, and Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jiaqian Wu
- The Vivian L. Smith Department of Neurosurgery, Center for Stem Cell and Regenerative Medicine, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, McGovern Medical School, UTHealth, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Binhai Zheng
- Department of Neurosciences, UC San Diego School of Medicine, La Jolla; VA San Diego Research Service, San Diego, CA, USA
| | - Eduardo R Zimmer
- Department of Pharmacology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Robert Zorec
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
- Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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6
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Yamazawa T, Ogawa H, Murayama T, Yamaguchi M, Oyamada H, Suzuki J, Kurebayashi N, Kanemaru K, Oguchi K, Sakurai T, Iino M. Insights into channel modulation mechanism of RYR1 mutants using Ca2+ imaging and molecular dynamics. J Gen Physiol 2021; 152:132759. [PMID: 31841587 PMCID: PMC7034096 DOI: 10.1085/jgp.201812235] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 07/31/2019] [Accepted: 11/05/2019] [Indexed: 12/01/2022] Open
Abstract
Molecular bases of pathogenic enhancement of Ca2+ release channel activities in RYR1 carrying disease-associated mutations at the N-terminal region were studied. Functional studies and MD simulation revealed that the interactions between domains have a strong correlation with channel activity. Type 1 ryanodine receptor (RYR1) is a Ca2+ release channel in the sarcoplasmic reticulum in skeletal muscle and plays an important role in excitation–contraction coupling. Mutations in the RYR1 gene cause severe muscle diseases such as malignant hyperthermia (MH), which is a disorder of CICR via RYR1. Thus far, >300 mutations in RYR1 have been reported in patients with MH. However, owing to a lack of comprehensive analysis of the structure–function relationship of mutant RYR1, the mechanism remains largely unknown. Here, we combined functional studies and molecular dynamics (MD) simulations of RYR1 bearing disease-associated mutations at the N-terminal region. When expressed in HEK293 cells, the mutant RYR1 caused abnormalities in Ca2+ homeostasis. MD simulations of WT and mutant RYR1s were performed using crystal structure of the N-terminal domain (NTD) monomer, consisting of A, B, and C domains. We found that the mutations located around the interdomain region differentially affected hydrogen bonds/salt bridges. Particularly, mutations at R402, which increase the open probability of the channel, cause clockwise rotation of BC domains with respect to the A domain by alteration of the interdomain interactions. Similar results were also obtained with artificial mutations that mimic alteration of the interactions. Our results reveal the importance of interdomain interactions within the NTD in the regulation of the RYR1 channel and provide insights into the mechanism of MH caused by the mutations at the NTD.
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Affiliation(s)
- Toshiko Yamazawa
- Department of Molecular Physiology, The Jikei University School of Medicine, Tokyo, Japan.,Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Haruo Ogawa
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Takashi Murayama
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan
| | - Maki Yamaguchi
- Department of Molecular Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hideto Oyamada
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Physiology, University of California, San Francisco, San Francisco, CA
| | - Nagomi Kurebayashi
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
| | - Katsuji Oguchi
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Takashi Sakurai
- Department of Pharmacology, Juntendo University School of Medicine, Tokyo, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
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7
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Kitajima N, Takikawa K, Sekiya H, Satoh K, Asanuma D, Sakamoto H, Takahashi S, Hanaoka K, Urano Y, Namiki S, Iino M, Hirose K. Real-time in vivo imaging of extracellular ATP in the brain with a hybrid-type fluorescent sensor. eLife 2020; 9:57544. [PMID: 32648544 PMCID: PMC7398694 DOI: 10.7554/elife.57544] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/09/2020] [Indexed: 02/06/2023] Open
Abstract
Adenosine 5' triphosphate (ATP) is a ubiquitous extracellular signaling messenger. Here, we describe a method for in-vivo imaging of extracellular ATP with high spatiotemporal resolution. We prepared a comprehensive set of cysteine-substitution mutants of ATP-binding protein, Bacillus FoF1-ATP synthase ε subunit, labeled with small-molecule fluorophores at the introduced cysteine residue. Screening revealed that the Cy3-labeled glutamine-105 mutant (Q105C-Cy3; designated ATPOS) shows a large fluorescence change in the presence of ATP, with submicromolar affinity, pH-independence, and high selectivity for ATP over ATP metabolites and other nucleotides. To enable in-vivo validation, we introduced BoNT/C-Hc for binding to neuronal plasma membrane and Alexa Fluor 488 for ratiometric measurement. The resulting ATPOS complex binds to neurons in cerebral cortex of living mice, and clearly visualized a concentrically propagating wave of extracellular ATP release in response to electrical stimulation. ATPOS should be useful to probe the extracellular ATP dynamics of diverse biological processes in vivo.
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Affiliation(s)
- Nami Kitajima
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kenji Takikawa
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Sekiya
- Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kaname Satoh
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Daisuke Asanuma
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Sakamoto
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shodai Takahashi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenjiro Hanaoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yasuteru Urano
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.,Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shigeyuki Namiki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masamitsu Iino
- Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence, The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Tokyo, Japan
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8
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Abstract
Mitochondrial Ca2+ dynamics are involved in the regulation of multifarious cellular processes, including intracellular Ca2+ signalling, cell metabolism and cell death. Use of mitochondria-targeted genetically encoded Ca2+ indicators has revealed intercellular and subcellular heterogeneity of mitochondrial Ca2+ dynamics, which are assumed to be determined by distinct thresholds of Ca2+ increases at each subcellular mitochondrial domain. The balance between Ca2+ influx through the mitochondrial calcium uniporter and extrusion by cation exchangers across the inner mitochondrial membrane may define the threshold; however, the precise mechanisms remain to be further explored. We here report the new red fluorescent genetically encoded Ca2+ indicators, R-CEPIA3mt and R-CEPIA4mt, which are targeted to mitochondria and their Ca2+ affinities are engineered to match the intramitochondrial Ca2+ concentrations. They enable visualization of mitochondrial Ca2+ dynamics with high spatiotemporal resolution in parallel with the use of green fluorescent probes and optogenetic tools. Thus, R-CEPIA3mt and R-CEPIA4mt are expected to be a useful tool for elucidating the mechanisms of the complex mitochondrial Ca2+ dynamics and their functions.
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Affiliation(s)
- Kazunori Kanemaru
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Junji Suzuki
- Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Isamu Taiko
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
- Department of Physiology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan.
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9
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Yamazawa T, Ogawa H, Murayama T, Yamaguchi M, Oyamada H, Suzuki J, Kurebayashi N, Kazunori K, Sakurai T, Iino M. Molecular Dynamics and Ca2+ Imaging of Mutant Type 1 Ryanodine Receptor. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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10
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Ito M, Kurebayashi N, Murayama T, Tamura M, Suzuki J, Kanemaru K, Iino M, Sakurai T. Improvements of ER-Ca2+ Based High-Throughput Screening Method for Searching Novel RyR2 Inhibitors. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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11
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Takahashi S, Hanaoka K, Okubo Y, Echizen H, Ikeno T, Komatsu T, Ueno T, Hirose K, Iino M, Nagano T, Urano Y. Rational Design of a Near-infrared Fluorescence Probe for Ca 2+ Based on Phosphorus-substituted Rhodamines Utilizing Photoinduced Electron Transfer. Chem Asian J 2020; 15:524-530. [PMID: 31909880 DOI: 10.1002/asia.201901689] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Indexed: 12/12/2022]
Abstract
Fluorescence imaging in the near-infrared (NIR) region (650-900 nm) is useful for bioimaging because background autofluorescence is low and tissue penetration is high in this range. In addition, NIR fluorescence is useful as a complementary color window to green and red for multicolor imaging. Here, we compared the photoinduced electron transfer (PeT)-mediated fluorescence quenching of silicon- and phosphorus-substituted rhodamines (SiRs and PRs) in order to guide the development of improved far-red to NIR fluorescent dyes. The results of density functional theory calculations and photophysical evaluation of a series of newly synthesized PRs confirmed that the fluorescence of PRs was more susceptible than that of SiRs to quenching via PeT. Based on this, we designed and synthesized a NIR fluorescence probe for Ca2+ , CaPR-1, and its membrane-permeable acetoxymethyl derivative, CaPR-1 AM, which is distributed to the cytosol, in marked contrast to our previously reported Ca2+ far-red to NIR fluorescence probe based on the SiR scaffold, CaSiR-1 AM, which is mainly localized in lysosomes as well as cytosol in living cells. CaPR-1 showed longer-wavelength absorption and emission (up to 712 nm) than CaSiR-1. The new probe was able to image Ca2+ at dendrites and spines in brain slices, and should be a useful tool in neuroscience research.
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Affiliation(s)
- Shodai Takahashi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kenjiro Hanaoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Honami Echizen
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Takayuki Ikeno
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Toru Komatsu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Tasuku Ueno
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, 30-1 Oyaguchi kamicho, Itabashi-ku, Tokyo, 173-8610, Japan
| | - Tetsuo Nagano
- Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yasuteru Urano
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Laboratory of Chemical Biology and Molecular Imaging, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, 1-7-1 Otemachi, Chiyoda-ku, Tokyo, 100-0004, Japan
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12
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Okubo Y, Iino M, Hirose K. Store-operated Ca 2+ entry-dependent Ca 2+ refilling in the endoplasmic reticulum in astrocytes. Biochem Biophys Res Commun 2019; 522:1003-1008. [PMID: 31812243 DOI: 10.1016/j.bbrc.2019.12.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 12/01/2019] [Indexed: 12/11/2022]
Abstract
Astrocytes regulate various brain functions, for which Ca2+ release from the endoplasmic reticulum (ER) often play crucial roles. Because astrocytic ER Ca2+ release is robust and frequent, the ER Ca2+ refilling mechanism should be critical for ongoing Ca2+ signaling in astrocytes. In this study, we focused on the putative functional significance of store-operated Ca2+ entry (SOCE) in ER Ca2+ refilling. We expressed the ER luminal Ca2+ indicator G-CEPIA1er in astrocytes in acute cortical slices to directly monitor the decrease and recovery of ER Ca2+ concentration upon spontaneous or norepinephrine-induced Ca2+ release. Inhibition of SOCE significantly slowed the recovery of ER Ca2+ concentration after Ca2+ release in astrocytes. This delayed recovery resulted in a prolonged decrease in the ER Ca2+ content in astrocytes with periodic spontaneous Ca2+ release, followed by the attenuation of cytosolic Ca2+ responses upon Ca2+ release. Therefore, our results provide direct evidence for the physiological significance of SOCE in ER Ca2+ refilling after ER Ca2+ release.
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Affiliation(s)
- Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 133-0033, Japan.
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, 30-1 Oyaguchi Kamicho, Itabashi-ku, Tokyo, 173-8610, Japan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 133-0033, Japan
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13
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Kanno M, Miura K, Masaki Y, Tsujimura H, Iino M, Takizawa J, Maeda Y, Yamamoto K, Tamura S, Yoshida A, Yagi H, Yoshida I, Kitazume K, Masunari T, Choi I, Kakinoki Y, Suzuki R, Yoshino T, Nakamura S, Yoshida T. CONSOLIDATION THERAPY USING 90
Y-IBRITUMOMAB TIUXETAN AFTER BENDAMUSTINE AND RITUXIMAB FOR RELAPSED FOLLICULAR LYMPHOMA; A MULTICENTER, PHASE II STUDY (BRiZ2012). Hematol Oncol 2019. [DOI: 10.1002/hon.61_2631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- M. Kanno
- Oncology Center; Nara Medical University Hospital; Kashihara Japan
| | - K. Miura
- Division of Hematology and Rheumatology; Nihon University School of Medicine; Tokyo Japan
| | - Y. Masaki
- Department of Hematology and Immunology; Kanazawa Medical University; Ishikawa Japan
| | - H. Tsujimura
- Division of Medical Oncology; Chiba Cancer Center; Chiba Japan
| | - M. Iino
- Department of Medical Oncology; Yamanashi Prefectural Central Hospital; Kofu Japan
| | - J. Takizawa
- Department of Hematology; Endocrinology and Metabolism, Niigata University Faculty of Medicine; Niigata Japan
| | - Y. Maeda
- Department of Hematology and Oncology; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
| | - K. Yamamoto
- Department of Hematology; Okayama City Hospital; Okayama Japan
| | - S. Tamura
- Department of Hematology/Oncology; Kinan Hospital; Tanabe Japan
| | - A. Yoshida
- Department of Hematology; Toyama Prefectural Central Hospital; Toyama Japan
| | - H. Yagi
- Department of Hematology and Oncology; Nara Prefecture General Medical Center; Nara Japan
| | - I. Yoshida
- Department of Hematologic Oncology; National Hospital Organization, Shikoku Cancer Center; Matsuyama Japan
| | - K. Kitazume
- Department of Hematology; Showa General Hospital; Kodaira Japan
| | - T. Masunari
- Department of Infectious Diseases; Chugoku Central Hospital; Fukuyama Japan
| | - I. Choi
- Department of Hematology; National Hospital Organization, Kyushu Cancer Center; Fukuoka Japan
| | - Y. Kakinoki
- Department of Hematology; Asahikawa City Hospital; Ashikawa Japan
| | - R. Suzuki
- Department of Oncology/Hematology, Innovative Cancer Center; Shimane University Hospital; Izumo Japan
| | - T. Yoshino
- Department of Pathology; Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences; Okayama Japan
| | - S. Nakamura
- Department of Pathology and Biological Response; Nagoya University Graduate School of Medicine; Nagoya Japan
| | - T. Yoshida
- Member; Society of Lymphoma Treatment in Japan (SoLT-J); Kanazawa Japan
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14
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Abstract
Astrocytes generate robust intracellular Ca2+ concentration changes (Ca2+ signals), which are assumed to regulate astrocytic functions that play crucial roles in the regulation of brain functions. One frequently used strategy for exploring the role of astrocytic Ca2+ signalling is the use of mice deficient in the type 2 inositol 1,4,5-trisphosphate receptor (IP3 R2). These IP3 R2-knockout (KO) mice are reportedly devoid of Ca2+ mobilization from the endoplasmic reticulum (ER) in astrocytes. However, they have shown no functional deficits in several studies, causing a heated debate as to the functional relevance of ER-mediated Ca2+ signalling in astrocytes. Recently, the assumption that Ca2+ mobilization from the ER is absent in IP3 R2-KO astrocytes has been re-evaluated using intraorganellar Ca2+ imaging techniques. The new results indicated that IP3 R2-independent Ca2+ release may generate Ca2+ nanodomains around the ER, which may help explain the absence of functional deficits in IP3 R2-KO mice.
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Affiliation(s)
- Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, 133-0033, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
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15
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Murayama T, Kurebayashi N, Yuasa-Ishigami M, Mori S, Ogawa H, Suzuki J, Kanemaru K, Iino M, Kagechika H, Sakurai T. Efficient High-Throughput Screening for Type 1 Ryanodine Receptor Inhibitors using ER Ca2+Measurements. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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16
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Kurebayashi N, Murayama T, Tamura M, Mori S, Yuasa-Ishigami M, Kagechika H, Suzuki J, Kanemaru K, Iino M, Morimoto S, Sakurai T. Effects of Novel RyR2 Inhibitors on Diseased Hearts. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.2809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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17
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Iino M, Yamamoto T. Efficacy and Safety of Biosimilar Filgrastim for Cord Blood Transplantation: A Single-Institution Retrospective Analysis. Transplant Proc 2018; 50:3804-3810. [DOI: 10.1016/j.transproceed.2018.06.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 06/07/2018] [Accepted: 06/27/2018] [Indexed: 01/20/2023]
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18
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Abstract
SIGNIFICANCE Properly controlled intracellular Ca2+ dynamics is crucial for regulation of neuronal function and survival in the central nervous system. The endoplasmic reticulum (ER), a major intracellular Ca2+ store, plays a critical role as a source and sink for neuronal Ca2+. Recent Advances: Accumulating evidence indicates that disrupted ER Ca2+ signaling is involved in neuronal cell death under various pathological conditions, providing novel insight into neurodegenerative disease mechanisms. CRITICAL ISSUES We summarize current knowledge concerning the relationship between abnormal ER Ca2+ dynamics and neuronal cell death. We also introduce recent technical advances for probing ER intraluminal Ca2+ dynamics with unprecedented spatiotemporal resolution. FUTURE DIRECTIONS Further studies on ER Ca2+ signaling are expected to provide progress for unmet medical needs in neurodegenerative disease. Antioxid. Redox Signal. 29, 1147-1157.
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Affiliation(s)
- Yohei Okubo
- 1 Department of Pharmacology, Graduate School of Medicine, The University of Tokyo , Tokyo, Japan
| | - Yoshinori Mikami
- 2 Department of Physiology, School of Medicine, Faculty of Medicine, Toho University , Tokyo, Japan
| | - Kazunori Kanemaru
- 1 Department of Pharmacology, Graduate School of Medicine, The University of Tokyo , Tokyo, Japan .,3 Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine , Tokyo, Japan
| | - Masamitsu Iino
- 3 Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine , Tokyo, Japan
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19
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Okubo Y, Kanemaru K, Suzuki J, Kobayashi K, Hirose K, Iino M. Inositol 1,4,5-trisphosphate receptor type 2-independent Ca2+
release from the endoplasmic reticulum in astrocytes. Glia 2018; 67:113-124. [DOI: 10.1002/glia.23531] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 08/13/2018] [Accepted: 08/15/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Yohei Okubo
- Department of Pharmacology; Graduate School of Medicine, The University of Tokyo; Tokyo Japan
| | - Kazunori Kanemaru
- Department of Pharmacology; Graduate School of Medicine, The University of Tokyo; Tokyo Japan
- Department of Cellular and Molecular Pharmacology; Nihon University School of Medicine; Tokyo Japan
| | - Junji Suzuki
- Department of Physiology; University of California San Francisco; San Francisco California
| | - Kenta Kobayashi
- Section of Viral Vector Development; National Institute for Physiological Sciences; Okazaki Japan
- The Graduate University for Advanced Studies (SOKENDAI); Hayama Japan
| | - Kenzo Hirose
- Department of Neurobiology; Graduate School of Medicine, The University of Tokyo; Tokyo Japan
| | - Masamitsu Iino
- Department of Cellular and Molecular Pharmacology; Nihon University School of Medicine; Tokyo Japan
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20
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Kanno M, Miura K, Masaki Y, Tsujimura H, Iino M, Takizawa J, Maeda Y, Yamamoto K, Tamura S, Yoshida A, Yagi H, Yoshida I, Kitazume K, Masunari T, Choi I, Kakinoki Y, Yoshino T, Nakamura S, Yoshida T. Bendamustine and rituximab followed by 90Y-ibritumomab tiuxetan for relapsed follicular lymphoma: A preliminary analysis of a multicenter, prospective phase II study (BRiZ2012). Ann Oncol 2018. [DOI: 10.1093/annonc/mdy286.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Murayama T, Kurebayashi N, Ishigami-Yuasa M, Mori S, Suzuki Y, Akima R, Ogawa H, Suzuki J, Kanemaru K, Oyamada H, Kiuchi Y, Iino M, Kagechika H, Sakurai T. Efficient High-Throughput Screening by Endoplasmic Reticulum Ca2+ Measurement to Identify Inhibitors of Ryanodine Receptor Ca2+-Release Channels. Mol Pharmacol 2018; 94:722-730. [DOI: 10.1124/mol.117.111468] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/12/2018] [Indexed: 11/22/2022] Open
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22
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Murakami TC, Mano T, Saikawa S, Horiguchi SA, Shigeta D, Baba K, Sekiya H, Shimizu Y, Tanaka KF, Kiyonari H, Iino M, Mochizuki H, Tainaka K, Ueda HR. A three-dimensional single-cell-resolution whole-brain atlas using CUBIC-X expansion microscopy and tissue clearing. Nat Neurosci 2018; 21:625-637. [DOI: 10.1038/s41593-018-0109-1] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 02/06/2018] [Indexed: 12/12/2022]
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23
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Ino D, Iino M. Schwann cell mitochondria as key regulators in the development and maintenance of peripheral nerve axons. Cell Mol Life Sci 2017; 74:827-835. [PMID: 27638763 PMCID: PMC11107563 DOI: 10.1007/s00018-016-2364-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/09/2016] [Indexed: 01/13/2023]
Abstract
Formation of myelin sheaths by Schwann cells (SCs) enables rapid and efficient transmission of action potentials in peripheral axons, and disruption of myelination results in disorders that involve decreased sensory and motor functions. Given that construction of SC myelin requires high levels of lipid and protein synthesis, mitochondria, which are pivotal in cellular metabolism, may be potential regulators of the formation and maintenance of SC myelin. Supporting this notion, abnormal mitochondria are found in SCs of neuropathic peripheral nerves in both human patients and the relevant animal models. However, evidence for the importance of SC mitochondria in myelination has been limited, until recently. Several studies have recently used genetic approaches that allow SC-specific ablation of mitochondrial metabolic activity in living animals to show the critical roles of SC mitochondria in the development and maintenance of peripheral nerve axons. Here, we review current knowledge about the involvement of SC mitochondria in the formation and dysfunction of myelinated axons in the peripheral nervous system.
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Affiliation(s)
- Daisuke Ino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Laboratory for Cell Polarity Regulation, RIKEN Quantitative Biology Center, 6-2-3, Furuedai, Suita, Osaka, 565-0874, Japan
| | - Masamitsu Iino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, 30-1, Oyaguchi kami-cho, Itabashi-ku, Tokyo, 173-8610, Japan.
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24
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Murayama T, Kurebayashi N, Ogawa H, Yamazawa T, Oyamada H, Suzuki J, Kanemaru K, Oguchi K, Iino M, Sakurai T. Genotype-Phenotype Correlations of Malignant Hyperthermia and Central Core Disease Mutations in the Central Region of the RYR1 Channel. Hum Mutat 2016; 37:1231-1241. [PMID: 27586648 DOI: 10.1002/humu.23072] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/29/2016] [Indexed: 01/05/2023]
Abstract
Type 1 ryanodine receptor (RYR1) is a Ca2+ release channel in the sarcoplasmic reticulum of skeletal muscle and is mutated in some muscle diseases, including malignant hyperthermia (MH) and central core disease (CCD). Over 200 mutations associated with these diseases have been identified, and most mutations accelerate Ca2+ -induced Ca2+ release (CICR), resulting in abnormal Ca2+ homeostasis in skeletal muscle. However, it remains largely unknown how specific mutations cause different phenotypes. In this study, we investigated the CICR activity of 14 mutations at 10 different positions in the central region of RYR1 (10 MH and four MH/CCD mutations) using a heterologous expression system in HEK293 cells. In live-cell Ca2+ imaging, the mutant channels exhibited an enhanced sensitivity to caffeine, a reduced endoplasmic reticulum Ca2+ content, and an increased resting cytoplasmic Ca2+ level. The three parameters for CICR (Ca2+ sensitivity for activation, Ca2+ sensitivity for inactivation, and attainable maximum activity, i.e., gain) were obtained by [3 H]ryanodine binding and fitting analysis. The mutant channels showed increased gain and Ca2+ sensitivity for activation in a site-specific manner. Genotype-phenotype correlations were explained well by the near-atomic structure of RYR1. Our data suggest that divergent CICR activity may cause various disease phenotypes by specific mutations.
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Affiliation(s)
- Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Haruo Ogawa
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, Jikei University School of Medicine, Tokyo, Japan
| | - Hideto Oyamada
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Katsuji Oguchi
- Department of Pharmacology, School of Medicine, Showa University, Tokyo, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
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25
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Abstract
The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous system. SC-selective genetic manipulation in living animals is a powerful technique for studying the molecular and cellular mechanisms of SC myelination and demyelination in vivo. While knockout/knockin and transgenic mice are powerful tools for studying SC biology, these methods are costly and time consuming. Viral vector-mediated transgene introduction into the sciatic nerve is a simpler and less laborious method. However, viral methods have limitations, such as toxicity, transgene size constraints, and infectivity restricted to certain developmental stages. Here, we describe a new method that allows selective transfection of myelinating SCs in the rodent sciatic nerve using electroporation. By applying electric pulses to the sciatic nerve at the site of plasmid DNA injection, genes of interest can be easily silenced or overexpressed in SCs in both neonatal and more mature animals. Furthermore, this in vivo electroporation method allows for highly efficient simultaneous expression of multiple transgenes. Our novel technique should enable researchers to efficiently manipulate SC gene expression, and facilitate studies on SC development and function.
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Affiliation(s)
- Daisuke Ino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo; Laboratory for Cell Polarity Regulation, Quantitative Biology Center, RIKEN;
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo
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26
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Mikami Y, Kanemaru K, Okubo Y, Nakaune T, Suzuki J, Shibata K, Sugiyama H, Koyama R, Murayama T, Ito A, Yamazawa T, Ikegaya Y, Sakurai T, Saito N, Kakizawa S, Iino M. Nitric Oxide-induced Activation of the Type 1 Ryanodine Receptor Is Critical for Epileptic Seizure-induced Neuronal Cell Death. EBioMedicine 2016; 11:253-261. [PMID: 27544065 PMCID: PMC5049986 DOI: 10.1016/j.ebiom.2016.08.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 08/05/2016] [Accepted: 08/12/2016] [Indexed: 01/27/2023] Open
Abstract
Status epilepticus (SE) is a life-threatening emergency that can cause neurodegeneration with debilitating neurological disorders. However, the mechanism by which convulsive SE results in neurodegeneration is not fully understood. It has been shown that epileptic seizures produce markedly increased levels of nitric oxide (NO) in the brain, and that NO induces Ca2+ release from the endoplasmic reticulum via the type 1 ryanodine receptor (RyR1), which occurs through S-nitrosylation of the intracellular Ca2+ release channel. Here, we show that through genetic silencing of NO-induced activation of the RyR1 intracellular Ca2+ release channel, neurons were rescued from seizure-dependent cell death. Furthermore, dantrolene, an inhibitor of RyR1, was protective against neurodegeneration caused by SE. These results demonstrate that NO-induced Ca2+ release via RyR is involved in SE-induced neurodegeneration, and provide a rationale for the use of RyR1 inhibitors for the prevention of brain damage following SE.
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Affiliation(s)
- Yoshinori Mikami
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Physiology, School of Medicine, Faculty of Medicine, Toho University, 5-21-16 Omori-Nishi, Ota-ku, Tokyo 143-8540, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takuya Nakaune
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazuki Shibata
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroki Sugiyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Murayama
- Department of Pharmacology, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Akihiro Ito
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan; Department of Neurosurgery, Graduate School of Medicine, Teikyo University, 2-11-1 Kaga, Itabashi-Ku, Tokyo 117-003, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, The Jikei University School of Medicine, 3-25-8 Nishishimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Sakurai
- Department of Pharmacology, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Nobuhito Saito
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Sho Kakizawa
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine, 30-1 Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan.
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27
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Suzuki J, Kanemaru K, Iino M. Genetically Encoded Fluorescent Indicators for Organellar Calcium Imaging. Biophys J 2016; 111:1119-1131. [PMID: 27477268 DOI: 10.1016/j.bpj.2016.04.054] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/30/2016] [Accepted: 04/01/2016] [Indexed: 12/14/2022] Open
Abstract
Optical Ca(2+) indicators are powerful tools for investigating intracellular Ca(2+) signals in living cells. Although a variety of Ca(2+) indicators have been developed, deciphering the physiological functions and spatiotemporal dynamics of Ca(2+) in intracellular organelles remains challenging. Genetically encoded Ca(2+) indicators (GECIs) using fluorescent proteins are promising tools for organellar Ca(2+) imaging, and much effort has been devoted to their development. In this review, we first discuss the key points of organellar Ca(2+) imaging and summarize the requirements for optimal organellar Ca(2+) indicators. Then, we highlight some of the recent advances in the engineering of fluorescent GECIs targeted to specific organelles. Finally, we discuss the limitations of currently available GECIs and the requirements for advancing the research on intraorganellar Ca(2+) signaling.
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Affiliation(s)
- Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Physiology, University of California San Francisco, San Francisco, California
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan.
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28
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Kubota J, Mikami Y, Kanemaru K, Sekiya H, Okubo Y, Iino M. Whisker experience-dependent mGluR signaling maintains synaptic strength in the mouse adolescent cortex. Eur J Neurosci 2016; 44:2004-14. [PMID: 27225340 DOI: 10.1111/ejn.13285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 05/13/2016] [Accepted: 05/22/2016] [Indexed: 11/28/2022]
Abstract
Sensory experience-dependent plasticity in the somatosensory cortex is a fundamental mechanism of adaptation to the changing environment not only early in the development but also in adolescence and adulthood. Although the mechanisms underlying experience-dependent plasticity during early development have been well documented, the corresponding understanding in the mature cortex is less complete. Here, we investigated the mechanism underlying whisker deprivation-induced synaptic plasticity in the barrel cortex in adolescent mice. Layer 4 (L4) to L2/3 excitatory synapses play a crucial role for whisker experience-dependent plasticity in rodent barrel cortex and whisker deprivation is known to depress synaptic strength at L4-L2/3 synapses in adolescent and adult animals. We found that whisker deprivation for 5 days or longer decreased the presynaptic glutamate release probability at L4-L2/3 synapses in the barrel cortex in adolescent mice. This whisker deprivation-induced depression was restored by daily administration of a positive allosteric modulator of the type 5 metabotropic glutamate receptor (mGluR5). On the other hand, the administration of mGluR5 antagonists reproduced the effect of whisker deprivation in whisker-intact mice. Furthermore, chronic and selective suppression of inositol 1,4,5-trisphosphate (IP3 ) signaling in postsynaptic L2/3 neurons decreased the presynaptic release probability at L4-L2/3 synapses. These findings represent a previously unidentified mechanism of cortical plasticity, namely that whisker experience-dependent mGluR5-IP3 signaling in the postsynaptic neurons maintains presynaptic function in the adolescent barrel cortex.
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Affiliation(s)
- Jun Kubota
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yoshinori Mikami
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Physiology, School of Medicine, Faculty of Medicine, Toho University, Ota-ku, Tokyo, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hiroshi Sekiya
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan
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29
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Kurebayashi N, Murayama T, Suzuki J, Kanemaru K, Iino M, Sakurai T. Characterization of Ca2+-Induced Ca2+ Release via RyR2 Carrying Arrhythmogenic Mutations. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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30
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Ino D, Sagara H, Suzuki J, Kanemaru K, Okubo Y, Iino M. Neuronal Regulation of Schwann Cell Mitochondrial Ca(2+) Signaling during Myelination. Cell Rep 2015; 12:1951-9. [PMID: 26365190 DOI: 10.1016/j.celrep.2015.08.039] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/01/2015] [Accepted: 08/12/2015] [Indexed: 11/24/2022] Open
Abstract
Schwann cells (SCs) myelinate peripheral neurons to promote the rapid conduction of action potentials, and the process of myelination is known to be regulated by signals from axons to SCs. Given that SC mitochondria are one of the potential regulators of myelination, we investigated whether SC mitochondria are regulated by axonal signaling. Here, we show a purinergic mechanism that sends information from neurons to SC mitochondria during myelination. Our results show that electrical stimulation of rat sciatic nerve increases extracellular ATP levels enough to activate purinergic receptors. Indeed, electrical stimulation of sciatic nerves induces Ca(2+) increases in the cytosol and the mitochondrial matrix of surrounding SCs via purinergic receptor activation. Chronic suppression of this pathway during active myelination suppressed the longitudinal and radial development of myelinating SCs and caused hypomyelination. These results demonstrate a neuron-to-SC mitochondria signaling, which is likely to have an important role in proper myelination.
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Affiliation(s)
- Daisuke Ino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Hiroshi Sagara
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, Tokyo 113-8654, Japan
| | - Junji Suzuki
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Yohei Okubo
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan
| | - Masamitsu Iino
- Department of Pharmacology, The University of Tokyo Graduate School of Medicine, Tokyo 113-0033, Japan.
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Murayama T, Kurebayashi N, Yamazawa T, Oyamada H, Suzuki J, Kanemaru K, Oguchi K, Iino M, Sakurai T. Divergent Activity Profiles of Type 1 Ryanodine Receptor Channels Carrying Malignant Hyperthermia and Central Core Disease Mutations in the Amino-Terminal Region. PLoS One 2015; 10:e0130606. [PMID: 26115329 PMCID: PMC4482644 DOI: 10.1371/journal.pone.0130606] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 05/21/2015] [Indexed: 11/25/2022] Open
Abstract
The type 1 ryanodine receptor (RyR1) is a Ca2+ release channel in the sarcoplasmic reticulum of skeletal muscle and is mutated in several diseases, including malignant hyperthermia (MH) and central core disease (CCD). Most MH and CCD mutations cause accelerated Ca2+ release, resulting in abnormal Ca2+ homeostasis in skeletal muscle. However, how specific mutations affect the channel to produce different phenotypes is not well understood. In this study, we have investigated 11 mutations at 7 different positions in the amino (N)-terminal region of RyR1 (9 MH and 2 MH/CCD mutations) using a heterologous expression system in HEK293 cells. In live-cell Ca2+ imaging at room temperature (~25 °C), cells expressing mutant channels exhibited alterations in Ca2+ homeostasis, i.e., an enhanced sensitivity to caffeine, a depletion of Ca2+ in the ER and an increase in resting cytoplasmic Ca2+. RyR1 channel activity was quantitatively evaluated by [3H]ryanodine binding and three parameters (sensitivity to activating Ca2+, sensitivity to inactivating Ca2+ and attainable maximum activity, i.e., gain) were obtained by fitting analysis. The mutations increased the gain and the sensitivity to activating Ca2+ in a site-specific manner. The gain was consistently higher in both MH and MH/CCD mutations. Sensitivity to activating Ca2+ was markedly enhanced in MH/CCD mutations. The channel activity estimated from the three parameters provides a reasonable explanation to the pathological phenotype assessed by Ca2+ homeostasis. These properties were also observed at higher temperatures (~37 °C). Our data suggest that divergent activity profiles may cause varied disease phenotypes by specific mutations. This approach should be useful for diagnosis and treatment of diseases with mutations in RyR1.
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Affiliation(s)
- Takashi Murayama
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
- * E-mail:
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
| | - Toshiko Yamazawa
- Department of Molecular Physiology, Jikei University School of Medicine, Tokyo 105–8461, Japan
| | - Hideto Oyamada
- Department of Pharmacology, School of Medicine, Showa University, Tokyo 142–8555, Japan
| | - Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Katsuji Oguchi
- Department of Pharmacology, School of Medicine, Showa University, Tokyo 142–8555, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113–0033, Japan
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo 113–8421, Japan
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Iino M. Functional and esthetic rehabilitation with maxillary prosthesis supported by zygomatic implants for a patient with maxillary defect resulting from cancer ablative surgery. J Oral Maxillofac Surg 2014. [DOI: 10.1016/j.joms.2014.06.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kanemaru K, Sekiya H, Xu M, Satoh K, Kitajima N, Yoshida K, Okubo Y, Sasaki T, Moritoh S, Hasuwa H, Mimura M, Horikawa K, Matsui K, Nagai T, Iino M, Tanaka KF. In vivo visualization of subtle, transient, and local activity of astrocytes using an ultrasensitive Ca(2+) indicator. Cell Rep 2014; 8:311-8. [PMID: 24981861 DOI: 10.1016/j.celrep.2014.05.056] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/16/2014] [Accepted: 05/30/2014] [Indexed: 10/25/2022] Open
Abstract
Astrocytes generate local calcium (Ca(2+)) signals that are thought to regulate their functions. Visualization of these signals in the intact brain requires an imaging method with high spatiotemporal resolution. Here, we describe such a method using transgenic mice expressing the ultrasensitive ratiometric Ca(2+) indicator yellow Cameleon-Nano 50 (YC-Nano50) in astrocytes. In these mice, we detected a unique pattern of Ca(2+) signals. These occur spontaneously, predominantly in astrocytic fine processes, but not the cell body. Upon sensory stimulation, astrocytes initially responded with Ca(2+) signals at fine processes, which then propagated to the cell body. These observations suggest that astrocytic fine processes function as a high-sensitivity detector of neuronal activities. Thus, the method provides a useful tool for studying the activity of astrocytes in brain physiology and pathology.
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Affiliation(s)
- Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Hiroshi Sekiya
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Ming Xu
- Department of Neuropsychiatry, School of Medicine, Keio University, Shinjuku, Tokyo 160-8582, Japan
| | - Kaname Satoh
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Nami Kitajima
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Keitaro Yoshida
- Department of Neuropsychiatry, School of Medicine, Keio University, Shinjuku, Tokyo 160-8582, Japan
| | - Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Takuya Sasaki
- Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, San Diego, San Diego, CA, 92093-0357, USA
| | - Satoru Moritoh
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
| | - Hidetoshi Hasuwa
- Genome Information Research Center, Osaka University, Suita 565-0871, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, School of Medicine, Keio University, Shinjuku, Tokyo 160-8582, Japan
| | - Kazuki Horikawa
- Support Center for Advanced Medical Sciences, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
| | - Ko Matsui
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki 567-0047, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University, Shinjuku, Tokyo 160-8582, Japan.
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Asano K, Kawamoto R, Iino M, Fruichi T, Nojiri K, Takamizawa T, Miyazaki M. Effect of Pre-reacted Glass-ionomer Filler Extraction Solution on Demineralization of Bovine Enamel. Oper Dent 2014; 39:159-65. [DOI: 10.2341/13-034-l] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective
To determine the effect of pre-reacted glass-ionomer (PRG) filler extraction solution on the demineralization of bovine enamel by measuring changes in the ultrasound transmission velocity.
Methods
The specimens were prepared by cutting bovine teeth into enamel blocks. The specimens were immersed in buffered lactic acid solution for 10 minutes twice a day, and then stored in artificial saliva. Other specimens were stored in PRG filler extraction solution for 10 minutes, followed by 10-minute immersion in the buffered lactic acid solution twice a day. The propagation time of longitudinal ultrasonic waves was measured by a pulser receiver. Six specimens were used for each condition, and analyses of variance followed by Tukey tests (α=0.05) were done.
Results
No changes in sonic velocity were found for specimens stored in the PRG filler extraction solution, indicating that the PRG extraction solution had an effect on inhibiting the demineralization of bovine enamel.
Conclusions
The results obtained with the use of an ultrasound measurement technique suggested that PRG filler extraction solution has the ability to prevent demineralization of enamel.
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Affiliation(s)
- K Asano
- Kazumasa Asano, DDS, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - R Kawamoto
- Ryo Kawamoto, DDS, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - M Iino
- Masayoshi Iino, DDS, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - T Fruichi
- Tetsuya Fruichi, DDS, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - K Nojiri
- Kie Nojiri, DDS, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - T Takamizawa
- Toshiki Takamizawa, DDS, PhD, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
| | - M Miyazaki
- Masashi Miyazaki, DDS, PhD, Operative Dentistry, Nihon University School of Dentistry, Chiyoda-Ku, Tokyo, Japan
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Yamazawa T, Murayama T, Oyamada H, Suzuki J, Kanemaru K, Kurebayashi N, Takemori S, Iino M. Functional Analysis of Ryanodine Receptor Carrying Malignant Hyperthermia Associated Mutations. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Iino M, Nakagomi H, Teramoto K. Characteristics of Malignant Lymphoma and the Treatment Outcomes in Patients Aged 80 Years or Over at Our Institution. Ann Oncol 2013. [DOI: 10.1093/annonc/mdt460.96] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Yano F, Saito T, Ogata N, Yamazawa T, Iino M, Chung UI, Kawaguchi H. β-catenin regulates parathyroid hormone/parathyroid hormone-related protein receptor signals and chondrocyte hypertrophy through binding to the intracellular C-terminal region of the receptor. ACTA ACUST UNITED AC 2013; 65:429-35. [PMID: 23124878 DOI: 10.1002/art.37779] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 10/25/2012] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To investigate the underlying mechanisms of action and functional relevance of β-catenin in chondrocytes, by examining the role of β-catenin as a novel protein that interacts with the intracellular C-terminal portion of the parathyroid hormone (PTH)/PTH-related protein (PTHrP) receptor type 1 (PTHR-1). METHODS The β-catenin-PTHR-1 binding region was determined with deletion and mutagenesis analyses of the PTHR1 C-terminus, using a mammalian two-hybrid assay. Physical interactions between these 2 molecules were examined with an in situ proximity ligation assay and immunostaining. To assess the effects of gain- and loss-of-function of β-catenin, transfection experiments were performed to induce overexpression of the constitutively active form of β-catenin (ca-β-catenin) and to block β-catenin activity with small interfering RNA, in cells cotransfected with either wild-type PTHR1 or mutant forms (lacking binding to β-catenin). Activation of the G protein α subunits G(αs) and G(αq) in the cells was determined by measurement of the intracellular cAMP accumulation and intracellular Ca(2+) concentration, while activation of canonical Wnt pathways was assessed using a TOPflash reporter assay. RESULTS In differentiated chondrocytes, β-catenin physically interacted and colocalized with the cell membrane-specific region of PTHR-1 (584-589). Binding of β-catenin to PTHR-1 caused suppression of the G(αs)/cAMP pathway and enhancement of the G(αq)/Ca(2+) pathway, without affecting the canonical Wnt pathway. Inhibition of Col10a1 messenger RNA (mRNA) expression by PTH was restored by overexpression of ca-β-catenin, even after blockade of the canonical Wnt pathway, and Col10a1 mRNA expression was further decreased by knockout of β-catenin (via the Cre recombinase) in chondrocytes from β-catenin-floxed mice. Mutagenesis analyses to block the binding of β-catenin to PTHR1 caused an inhibition of chondrocyte hypertrophy markers. CONCLUSION β-catenin binds to the PTHR-1 C-tail and switches the downstream signaling pathway from G(αs)/cAMP to G(αq)/Ca(2+), which is a possible mechanism by which chondrocyte hypertrophy may be regulated through the PTH/PTHrP signal independent of the canonical Wnt pathway.
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Kakizawa S, Yamazawa T, Iino M. Nitric oxide-induced calcium release: activation of type 1 ryanodine receptor by endogenous nitric oxide. Channels (Austin) 2012; 7:1-5. [PMID: 23247505 DOI: 10.4161/chan.22555] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyRs), located in the sarcoplasmic/endoplasmic reticulum (SR/ER) membrane, are required for intracellular Ca2+ release that is involved in a wide range of cellular functions. In addition to Ca2+-induced Ca2+ release in cardiac cells and voltage-induced Ca2+ release in skeletal muscle cells, we recently identified another mode of intracellular Ca2+ mobilization mediated by RyR, i.e., nitric oxide-induced Ca2+ release (NICR), in cerebellar Purkinje cells. NICR is evoked by neuronal activity, is dependent on S-nitrosylation of type 1 RyR (RyR1) and is involved in the induction of long-term potentiation (LTP) of cerebellar synapses. In this addendum, we examined whether peroxynitrite, which is produced by the reaction of nitric oxide with superoxide, may also have an effect on the Ca2+ release via RyR1 and the cerebellar LTP. We found that scavengers of peroxynitrite have no significant effect either on the Ca2+ release via RyR1 or on the cerebellar LTP. We also found that an application of a high concentration of peroxynitrite does not reproduce neuronal activity-dependent Ca2+ release in Purkinje cells. These results support that NICR is induced by endogenous nitric oxide produced by neuronal activity through S-nitrosylation of RyR1.
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Affiliation(s)
- Sho Kakizawa
- Department of Biological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
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Iino M, Nakagomi H, Teramoto K. Screening for Hepatitis B Virus Carriers and the Incidence of Hepatitis B Reactivation in Patients with Malignant Lymphoma at Our Institution. Ann Oncol 2012. [DOI: 10.1016/s0923-7534(20)32535-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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40
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Kakizawa S, Yamazawa T, Chen Y, Ito A, Murayama T, Oyamada H, Kurebayashi N, Sato O, Watanabe M, Mori N, Oguchi K, Sakurai T, Takeshima H, Saito N, Iino M. Nitric oxide-induced calcium release via ryanodine receptors regulates neuronal function. EMBO J 2011; 31:417-28. [PMID: 22036948 DOI: 10.1038/emboj.2011.386] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 09/28/2011] [Indexed: 12/13/2022] Open
Abstract
Mobilization of intracellular Ca(2+) stores regulates a multitude of cellular functions, but the role of intracellular Ca(2+) release via the ryanodine receptor (RyR) in the brain remains incompletely understood. We found that nitric oxide (NO) directly activates RyRs, which induce Ca(2+) release from intracellular stores of central neurons, and thereby promote prolonged Ca(2+) signalling in the brain. Reversible S-nitrosylation of type 1 RyR (RyR1) triggers this Ca(2+) release. NO-induced Ca(2+) release (NICR) is evoked by type 1 NO synthase-dependent NO production during neural firing, and is essential for cerebellar synaptic plasticity. NO production has also been implicated in pathological conditions including ischaemic brain injury, and our results suggest that NICR is involved in NO-induced neuronal cell death. These findings suggest that NICR via RyR1 plays a regulatory role in the physiological and pathophysiological functions of the brain.
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Affiliation(s)
- Sho Kakizawa
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
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Kubota J, Okubo Y, Iino M. Postsynaptic inositol 1,4,5-trisphosphate signaling maintains presynaptic function in the somatosensory cortex. Neurosci Res 2011. [DOI: 10.1016/j.neures.2011.07.494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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42
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Okubo Y, Mashimo M, Yamazawa T, Yamasaki M, Watanabe M, Murayama T, Iino M. Inositol 1,4,5-trisphosphate signaling maintains the activity of glutamate uptake in Bergmann glia. Neurosci Res 2011. [DOI: 10.1016/j.neures.2011.07.1431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Intracellular Ca(2+) signaling, and related mechanisms involving inositol 1,4,5-trisphosphate (IP(3)), nitric oxide, and the excitatory neurotransmitter glutamate, play a major role in the regulation of cellular function in the brain. Due to the complex morphology of central neurons, the correct spatiotemporal distribution of signaling molecules is essential. Thus, imaging studies have been particularly useful in elucidating the functions of these signaling molecules. The advancement of imaging methods, together with the development of a new method for the specific inhibition of intracellular IP(3) signaling, have made it possible to identify pathways that are regulated by Ca(2+) signals in the brain, including Ca(2+)-dependent synaptic maintenance and glial cell-dependent neurite growth. Further investigation of Ca(2+)-related signaling is expected to increase our understanding of brain function in the future.
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Affiliation(s)
- Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system. Although glutamate mediates synaptically confined point-to-point transmission, it has been suggested that under certain conditions glutamate may escape from the synaptic cleft (glutamate spillover), accumulate in the extrasynaptic space, and mediate volume transmission to regulate important brain functions. However, the inability to directly measure glutamate dynamics around active synapses has limited our understanding of glutamatergic volume transmission. The recent development of a family of fluorescent glutamate indicators has enabled the visualization of extrasynaptic glutamate dynamics in brain tissues. In this topical review, we examine glutamate as a volume transmitter based on novel results of glutamate imaging in the brain.
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Affiliation(s)
- Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Mashimo M, Okubo Y, Yamazawa T, Yamasaki M, Watanabe M, Murayama T, Iino M. Inositol 1,4,5-trisphosphate signaling maintains the activity of glutamate uptake in Bergmann glia. Eur J Neurosci 2010; 32:1668-77. [PMID: 20958799 DOI: 10.1111/j.1460-9568.2010.07452.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The maintenance of synaptic functions is essential for neuronal information processing in the adult brain. Astrocytes express glutamate transporters that rapidly remove glutamate from the extracellular space and they play a critical role in the precise operation of glutamatergic transmission. However, how the glutamate clearance function of astrocytes is maintained remains elusive. Here, we describe a maintenance mechanism for the glutamate uptake capacity of Bergmann glial cells (BGs) in the cerebellum. When inositol 1,4,5-trisphosphate (IP(3) ) signaling was chronically and selectively inhibited in BGs in vivo, the retention time of glutamate around parallel fiber-Purkinje cell synapses was increased. Under these conditions, a decrease in the level of the glutamate/aspartate transporter (GLAST) in BGs was observed. The same effects were observed after chronic in vivo inhibition of purinergic P2 receptors in the cerebellar cortex. These results suggest that the IP(3) signaling cascade is involved in regulating GLAST levels in BGs to maintain glutamate clearance in the mature cerebellum.
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Affiliation(s)
- Masato Mashimo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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O'Donnell C, Iino M, Mansharan K, Leditscke J, Woodford N. Contribution of postmortem multidetector CT scanning to identification of the deceased in a mass disaster: Experience gained from the 2009 Victorian bushfires. Forensic Sci Int 2010; 205:15-28. [PMID: 20691550 DOI: 10.1016/j.forsciint.2010.05.026] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 05/26/2010] [Indexed: 11/26/2022]
Abstract
CT scanning of the deceased is an established technique performed on all individuals admitted to VIFM over the last 5 years. It is used primarily to assist pathologists in determining cause and manner of death but is also invaluable for identification of unknown deceased individuals where traditional methods are not possible. Based on this experience, CT scanning was incorporated into phase 2 of the Institute's DVI process for the 2009 Victorian bushfires. All deceased individuals and fragmented remains admitted to the mortuary were CT scanned in their body bags using established protocols. Images were reviewed by 2 teams of 2 radiologists experienced in forensic imaging and the findings transcribed onto a data sheet constructed specifically for the DVI exercise. The contents of 255 body bags were examined in the 28 days following the fires. 164 missing persons were included in the DVI process with 163 deceased individuals eventually identified. CT contributed to this identification in 161 persons. In 2 cases, radiologists were unable to recognize commingled remains. CT was utilized in the initial triage of each bag's contents. If radiological evaluation determined that bodies were incomplete then this information was provided to search teams who revisited the scenes of death. CT was helpful in differentiation of human from non-human remains in 8 bags, recognition of human/animal commingling in 10 bags and human commingling in 6 bags. In 61% of cases gender was able to be determined on CT using a novel technique of genitalia detection and in all but 2 cases this was correct. Age range was able to be determined on CT in 94% with an accuracy of 76%. Specific identification features detected on CT included the presence of disease (14 disease entities in 13 cases), medical devices (26 devices in 19 cases) and 274 everyday metallic items associated with the remains of 135 individuals. CT scanning provided useful information prior to autopsy by flagging likely findings including the presence of non-human remains, at the time of autopsy by assisting in the localization of identifying features in heavily disfigured bodies, and after autopsy by retrospective review of images for clarification of issues that arose at the time of pathologist case review. In view of the success of CT scanning in this mass disaster, DVI administrators should explore the incorporation of CT services into their disaster plans.
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Affiliation(s)
- C O'Donnell
- Victorian Institute of Forensic Medicine, Australia; Department of Forensic Medicine, Monash University, Australia
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47
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Abstract
Positive phototropic curvature of Phycomyces sporangiophores (stage I) induced by a short pulse (10 sec) of blue light has been characterized. The curvature response, measured 40 min after irradiation, increases with increasing fluences up to approximately 10(-4) J.m(-2); it then decreases and becomes nearly 0 at a fluence of approximately 10(-1) J.m(-2). The threshold fluence is found near 10(-7) J.m(-2), indicating over 1000-fold higher sensitivity than the first positive phototropism of grass coleoptiles. Positive curvature of the sporangiophore becomes detectable 5 min after irradiation and increases with time up to approximately 40 min. During the course of this curvature development, overall elongation growth of the sporangiophore is first stimulated and then inhibited. The relationship between the phototropic response and the response in overall elongation growth is discussed, and it is suggested that the primary mechanisms of these responses are distinct.
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Affiliation(s)
- M Iino
- Carnegie Institution of Washington, Department of Plant Biology, 290 Panama Street, Stanford, CA 94305
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Abstract
The stomatal response to blue light was analyzed with gas-exchange techniques in Commelina communis L. leaves by using high-fluence-rate short pulses. Pulses of blue light were given under a background of high-fluence-rate red light, which maintained photosynthesis at near saturation and stomatal conductance at a steady state. A single blue light pulse of 1-100 sec induced an increase in stomatal conductance, which peaked after 15 min and then returned to the initial steady-state level within 50-60 min after the pulse. The response could be repeatedly induced in the same leaf. Red light pulses on a red background did not induce any comparable response. The stomatal response quantified by integrating the conductance increases after pulse application approached saturation with increasing pulse duration (t((1/2)) approximately 9 sec with 250 mumol.m(-2).sec(-1) of blue light). After a saturating pulse, sensitivity to a second pulse was restored slowly. This recovery response, quantified from the conductance increases caused by the two pulses, approached saturation with a t((1/2)) of approximately 9 min. These results were used to test a model in which a molecular component in the sensory transduction process is considered to exist in two interconvertible forms, A and B. If B is the physiologically active form inducing stomatal opening, then A is the inactive form. The A to B conversion is a light-induced reaction and the B to A conversion is a thermal reaction. Rate constants for these reactions were estimated from single- and double-pulse experiments (at a fluence rate of 250 mumol.m(-2).sec(-1), k(1) = 0.075 sec(-1); thermal rate constant k(d) = 0.0014 sec(-1)), allowing the calculation of steady-state concentration of B under continuous irradiation. The calculated values accurately predicted the steady-state stomatal conductances under continuous blue light.
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Affiliation(s)
- M Iino
- Carnegie Institute of Washington, Department of Plant Biology, 290 Panama Street, Stanford, CA 94305
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49
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Iino M. Spatiotemporal dynamics of Ca2+ signaling and its physiological roles. Proc Jpn Acad Ser B Phys Biol Sci 2010; 86:244-256. [PMID: 20228624 PMCID: PMC3417849 DOI: 10.2183/pjab.86.244] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 02/15/2010] [Indexed: 05/28/2023]
Abstract
Changes in the intracellular Ca(2+) concentration regulate numerous cell functions and display diverse spatiotemporal dynamics, which underlie the versatility of Ca(2+) in cell signaling. In many cell types, an increase in the intracellular Ca(2+) concentration starts locally, propagates within the cell (Ca(2+) wave) and makes oscillatory changes (Ca(2+) oscillation). Studies of the intracellular Ca(2+) release mechanism from the endoplasmic reticulum (ER) showed that the Ca(2+) release mechanism has inherent regenerative properties, which is essential for the generation of Ca(2+) waves and oscillations. Ca(2+) may shuttle between the ER and mitochondria, and this appears to be important for pacemaking of Ca(2+) oscillations. Importantly, Ca(2+) oscillations are an efficient mechanism in regulating cell functions, having effects supra-proportional to the sum of duration of Ca(2+) increase. Furthermore, Ca(2+) signaling mechanism studies have led to the development of a method for specific inhibition of Ca(2+) signaling, which has been used to identify hitherto unrecognized functions of Ca(2+) signals.
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Affiliation(s)
- Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
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Kanemaru K, Yohei O, Hirose K, Iino M. A novel translational regulator of Ca2+ signal-dependent maintenance of N-cadherin expression in astrocytes. Neurosci Res 2010. [DOI: 10.1016/j.neures.2010.07.1040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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