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Tachibana H, Nomura M, Funakoshi T, Unuma K, Aki T, Uemura K. Incomplete autophagy and increased cholesterol synthesis during neuronal cell death caused by a synthetic cannabinoid, CP-55,940. Neurotoxicology 2024; 103:215-221. [PMID: 38942151 DOI: 10.1016/j.neuro.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/17/2024] [Accepted: 06/25/2024] [Indexed: 06/30/2024]
Abstract
There is a propensity for synthetic cannabinoid abuse to spread worldwide. CP-55,940, a synthetic cannabinoid having the ability to activate both CB1 and CB2 receptors, has been shown to induce cell death in neurons as well as other cells. Here we investigate molecular events underling the adverse effects of CP-55,940 on neuronal cells. Exposure of mouse neuroblastoma Neuro2a cells to 10-50 µM CP-55,940 results in concentration-dependent cell death that is not accompanied by an induction of apoptosis. CP-55,940 also stimulates autophagy, but the stimulation is not followed by an increase in autophagic degradation. Transcriptome analysis using DNA microarray revealed the increased expression of genes for the cholesterol biosynthesis pathway that is associated with the activation of SREBP-2, the master transcriptional regulator of cholesterol biosynthesis. However, free cholesterol is localized mainly to cytoplasmic structures, although it is localized to the plasma membrane in healthy cells. Thus, cellular trafficking of cholesterol seems to be somewhat disrupted in CP-55,940 stimulated cells. These results show for the first time that CP-55,940 stimulates autophagy as well as cholesterol biosynthesis, although not all the processes involved in the cellular response to CP-55,940 seem to be complete in these cells.
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Affiliation(s)
- Hikari Tachibana
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Moeka Nomura
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takeshi Funakoshi
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kana Unuma
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Toshihiko Aki
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
| | - Koichi Uemura
- Department of Forensic Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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2
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Xu J, Peng Q, Cai J, Shangguan J, Su W, Chen G, Sun H, Zhu C, Gu Y. The Schwann cell-specific G-protein Gαo (Gnao1) is a cell-intrinsic controller contributing to the regulation of myelination in peripheral nerve system. Acta Neuropathol Commun 2024; 12:24. [PMID: 38331815 PMCID: PMC10854112 DOI: 10.1186/s40478-024-01720-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/27/2023] [Indexed: 02/10/2024] Open
Abstract
Myelin sheath abnormality is the cause of various neurodegenerative diseases (NDDs). G-proteins and their coupled receptors (GPCRs) play the important roles in myelination. Gnao1, encoding the major Gα protein (Gαo) in mammalian nerve system, is required for normal motor function. Here, we show that Gnao1 restricted to Schwann cell (SCs) lineage, but not neurons, negatively regulate SC differentiation, myelination, as well as re-myelination in peripheral nervous system (PNS). Mice lacking Gnao1 expression in SCs exhibit faster re-myelination and motor function recovery after nerve injury. Conversely, mice with Gnao1 overexpression in SCs display the insufficient myelinating capacity and delayed re-myelination. In vitro, Gnao1 deletion in SCs promotes SC differentiation. We found that Gnao1 knockdown in SCs resulting in the elevation of cAMP content and the activation of PI3K/AKT pathway, both associated with SC differentiation. The analysis of RNA sequencing data further evidenced that Gnao1 deletion cause the increased expression of myelin-related molecules and activation of regulatory pathways. Taken together, our data indicate that Gnao1 negatively regulated SC differentiation by reducing cAMP level and inhibiting PI3K-AKT cascade activation, identifying a novel drug target for the treatment of demyelinating diseases.
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Affiliation(s)
- Jinghui Xu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Qianqian Peng
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Jieyi Cai
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Jianghong Shangguan
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Wenfeng Su
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Gang Chen
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Hualin Sun
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China
| | - Changlai Zhu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China.
| | - Yun Gu
- Jiangsu Key Laboratory of Neuroregeneration, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS, 226001, People's Republic of China.
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Lu H, Wang Q, Jiang X, Zhao Y, He M, Wei M. The Potential Mechanism of Cannabidiol (CBD) Treatment of Epilepsy in Pentetrazol (PTZ) Kindling Mice Uncovered by Multi-Omics Analysis. Molecules 2023; 28:molecules28062805. [PMID: 36985783 PMCID: PMC10056192 DOI: 10.3390/molecules28062805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/05/2023] [Accepted: 03/15/2023] [Indexed: 03/30/2023] Open
Abstract
Cannabidiol (CBD) is the main active ingredient in the cannabis plant used for treating epilepsy and related diseases. However, how CBD ameliorates epilepsy and its effect on the hippocampus remains unknown. Herein, we evaluated how CBD ameliorates seizure degree in pentylenetetrazol (PTZ) induced epilepsy mice after being exposed to CBD (10 mg/kg p.o). In addition, transcriptome and metabolomic analysis were performed on the hippocampus. Our results suggested that CBD could alleviate PTZ-induced seizure, of which the NPTX2, Gprc5c, Lipg, and Stc2 genes were significantly down-regulated in mice after being exposed to PTZ. Transcriptome analysis showed 97 differently expressed genes (CBD) and the PTZ groups. Metabonomic analysis revealed that compared with the PTZ group, 41 up-regulated and 67 down-regulated metabolites were identified in the hippocampus of epileptic mice exposed to CBD. The correlation analysis for transcriptome and metabolome showed that (±) 15-HETE and carnitine C6:0 were at the core of the network and were involved in the positive or negative regulation of the related genes after being treated with CBD. In conclusion, CBD ameliorates epilepsy by acting on the metabolism, calcium signaling pathway, and tuberculosis pathways in the hippocampus. Our study provided a practical basis for the therapeutic potential of treating epilepsy using CBD.
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Affiliation(s)
- Hongyuan Lu
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Qinbiao Wang
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Xiaowen Jiang
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yanyun Zhao
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Miao He
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Minjie Wei
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
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Iwasa K, Yamagishi A, Yamamoto S, Haruta C, Maruyama K, Yoshikawa K. GPR137 Inhibits Cell Proliferation and Promotes Neuronal Differentiation in the Neuro2a Cells. Neurochem Res 2023; 48:996-1008. [PMID: 36436172 PMCID: PMC9922245 DOI: 10.1007/s11064-022-03833-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/08/2022] [Accepted: 11/19/2022] [Indexed: 11/28/2022]
Abstract
The orphan receptor, G protein-coupled receptor 137 (GPR137), is an integral membrane protein involved in several types of cancer. GPR137 is expressed ubiquitously, including in the central nervous system (CNS). We established a GPR137 knockout (KO) neuro2A cell line to analyze GPR137 function in neuronal cells. KO cells were generated by genome editing using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and cultured as single cells by limited dilution. Rescue cells were then constructed to re-express GPR137 in GPR137 KO neuro2A cells using an expression vector with an EF1-alpha promoter. GPR137 KO cells increased cellular proliferation and decreased neurite outgrowth (i.e., a lower level of neuronal differentiation). Furthermore, GPR137 KO cells exhibited increased expression of a cell cycle regulator, cyclin D1, and decreased expression of a neuronal differentiation marker, NeuroD1. Additionally, GPR137 KO cells exhibited lower expression levels of the neurite outgrowth markers STAT3 and GAP43. These phenotypes were all abrogated in the rescue cells. In conclusion, GPR137 deletion increased cellular proliferation and decreased neuronal differentiation, suggesting that GPR137 promotes cell cycle exit and neuronal differentiation in neuro2A cells. Regulation of neuronal differentiation by GPR137 could be vital to constructing neuronal structure during brain development.
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Affiliation(s)
- Kensuke Iwasa
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan
| | - Anzu Yamagishi
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan
| | - Shinji Yamamoto
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan
| | - Chikara Haruta
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan
| | - Kei Maruyama
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan
| | - Keisuke Yoshikawa
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, 38 Moro-Hongo, Moroyama-Machi, Iruma-Gun, Saitama, 350-0495, Japan.
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Inazumi H, Kuwahara K. NRSF/REST-Mediated Epigenomic Regulation in the Heart: Transcriptional Control of Natriuretic Peptides and Beyond. BIOLOGY 2022; 11:biology11081197. [PMID: 36009824 PMCID: PMC9405064 DOI: 10.3390/biology11081197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Reactivation of the fetal cardiac gene program, such as those encoding atrial and brain natriuretic peptides (ANP and BNP, respectively), is a characteristic feature of failing hearts. We previously revealed that a transcriptional repressor, neuron-restrictive silencer factor (NRSF), also called repressor element-1-silencing transcription factor (REST), plays a crucial role in the transcriptional control of ANP, BNP and other fetal cardiac genes through collaboration with various other transcription factors to maintain physiological cardiac function and electrical stability. Increased production of ANP and BNP prevents the progression of heart failure, but reactivation of Gαo and fetal-type cardiac ion channels (T-type Ca2+ and HCN channels) leads to deteriorated cardiac function and lethal arrhythmias observed in mice with disturbed NRSF function. Epigenetic regulators with which NRSF forms a complex modify histone acetylation and methylation, thereby participating in NRSF-mediated transcriptional regulation. Further comprehensive studies will lead to clarification of the molecular mechanisms underlying the development of cardiac dysfunction and heart failure. Abstract Reactivation of fetal cardiac genes, including those encoding atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), is a key feature of pathological cardiac remodeling and heart failure. Intensive studies on the regulation of ANP and BNP have revealed the involvement of numerous transcriptional factors in the regulation of the fetal cardiac gene program. Among these, we identified that a transcriptional repressor, neuron-restrictive silencer factor (NRSF), also named repressor element-1-silencing transcription factor (REST), which was initially detected as a transcriptional repressor of neuron-specific genes in non-neuronal cells, plays a pivotal role in the transcriptional regulation of ANP, BNP and other fetal cardiac genes. Here we review the transcriptional regulation of ANP and BNP gene expression and the role of the NRSF repressor complex in the regulation of cardiac gene expression and the maintenance of cardiac homeostasis.
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Affiliation(s)
- Hideaki Inazumi
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin-kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Koichiro Kuwahara
- Department of Cardiovascular Medicine, School of Medicine, Shinshu University, 3-1-1 Asahi, Nagano 390-8621, Japan
- Correspondence: ; Tel.: +81-263-37-3191; Fax: +81-263-37-3195
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Hansen J, Siddiq MM, Yadaw AS, Tolentino RE, Rabinovich V, Jayaraman G, Jain MR, Liu T, Li H, Xiong Y, Goldfarb J, Iyengar R. Whole cell response to receptor stimulation involves many deep and distributed subcellular biochemical processes. J Biol Chem 2022; 298:102325. [PMID: 35926710 PMCID: PMC9520007 DOI: 10.1016/j.jbc.2022.102325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/28/2022] Open
Abstract
Neurite outgrowth is an integrated whole cell response triggered by the cannabinoid-1 receptor. We sought to identify the many different biochemical pathways that contribute to this whole cell response. To understand underlying mechanisms, we identified subcellular processes (SCPs) composed of one or more biochemical pathways and their interactions required for this response. Differentially expressed genes and proteins were obtained from bulk transcriptomics and proteomic analysis of extracts from cells stimulated with a cannabinoid-1 receptor agonist. We used these differentially expressed genes and proteins to build networks of interacting SCPs by combining the expression data with prior pathway knowledge. From these SCP networks, we identified additional genes that when ablated, experimentally validated the SCP involvement in neurite outgrowth. Our experiments and informatics modeling allowed us to identify diverse SCPs such as those involved in pyrimidine metabolism, lipid biosynthesis, and mRNA splicing and stability, along with more predictable SCPs such as membrane vesicle transport and microtubule dynamics. We find that SCPs required for neurite outgrowth are widely distributed among many biochemical pathways required for constitutive cellular functions, several of which are termed ‘deep’, since they are distal to signaling pathways and the key SCPs directly involved in extension of the neurite. In contrast, ‘proximal’ SCPs are involved in microtubule growth and membrane vesicle transport dynamics required for neurite outgrowth. From these bioinformatics and dynamical models based on experimental data, we conclude that receptor-mediated regulation of subcellular functions for neurite outgrowth is both distributed, that is, involves many different biochemical pathways, and deep.
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Affiliation(s)
- Jens Hansen
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Mustafa M Siddiq
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Arjun Singh Yadaw
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Rosa E Tolentino
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Vera Rabinovich
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Gomathi Jayaraman
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Mohit Raja Jain
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, NY, 07103, United States
| | - Tong Liu
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, NY, 07103, United States
| | - Hong Li
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, New Jersey Medical School, Newark, NY, 07103, United States
| | - Yuguang Xiong
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Joseph Goldfarb
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Ravi Iyengar
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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7
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Inazumi H, Kuwahara K, Nakagawa Y, Kuwabara Y, Numaga-Tomita T, Kashihara T, Nakada T, Kurebayashi N, Oya M, Nonaka M, Sugihara M, Kinoshita H, Moriuchi K, Yanagisawa H, Nishikimi T, Motoki H, Yamada M, Morimoto S, Otsu K, Mortensen RM, Nakao K, Kimura T. NRSF- GNAO1 Pathway Contributes to the Regulation of Cardiac Ca 2+ Homeostasis. Circ Res 2022; 130:234-248. [PMID: 34875852 DOI: 10.1161/circresaha.121.318898] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND During the development of heart failure, a fetal cardiac gene program is reactivated and accelerates pathological cardiac remodeling. We previously reported that a transcriptional repressor, NRSF (neuron restrictive silencer factor), suppresses the fetal cardiac gene program, thereby maintaining cardiac integrity. The underlying molecular mechanisms remain to be determined, however. METHODS We aim to elucidate molecular mechanisms by which NRSF maintains normal cardiac function. We generated cardiac-specific NRSF knockout mice and analyzed cardiac gene expression profiles in those mice and mice cardiac-specifically expressing a dominant-negative NRSF mutant. RESULTS We found that cardiac expression of Gαo, an inhibitory G protein encoded in humans by GNAO1, is transcriptionally regulated by NRSF and is increased in the ventricles of several mouse models of heart failure. Genetic knockdown of Gnao1 ameliorated the cardiac dysfunction and prolonged survival rates in these mouse heart failure models. Conversely, cardiac-specific overexpression of GNAO1 in mice was sufficient to induce cardiac dysfunction. Mechanistically, we observed that increasing Gαo expression increased surface sarcolemmal L-type Ca2+ channel activity, activated CaMKII (calcium/calmodulin-dependent kinase-II) signaling, and impaired Ca2+ handling in ventricular myocytes, which led to cardiac dysfunction. CONCLUSIONS These findings shed light on a novel function of Gαo in the regulation of cardiac Ca2+ homeostasis and systolic function and suggest Gαo may be an effective therapeutic target for the treatment of heart failure.
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Affiliation(s)
- Hideaki Inazumi
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
| | - Koichiro Kuwahara
- Cardiovascular Medicine (K.K., M.O., H.M.), School of Medicine, Shinshu University, Matsumoto
| | - Yasuaki Nakagawa
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
| | - Yoshihiro Kuwabara
- Center for Accessing Early Promising Treatment, Kyoto University Hospital (Y.K.)
| | - Takuro Numaga-Tomita
- Molecular Pharmacology (T.N.-T., M.Y.), School of Medicine, Shinshu University, Matsumoto
| | - Toshihide Kashihara
- Molecular Pharmacology, School of Pharmaceutical Sciences, Kitasato University, Tokyo (T. Kashihara)
| | - Tsutomu Nakada
- Research Center for Supports to Advanced Science (T. Nakada), School of Medicine, Shinshu University, Matsumoto
| | - Nagomi Kurebayashi
- Cellular and Molecular Pharmacology, School of Medicine, Juntendo University, Tokyo (N.K.)
| | - Miku Oya
- Cardiovascular Medicine (K.K., M.O., H.M.), School of Medicine, Shinshu University, Matsumoto
| | - Miki Nonaka
- Pain Control Research, The Jikei University School of Medicine (M.N.)
| | - Masami Sugihara
- Clinical Laboratory Medicine, School of Medicine, Juntendo University, Tokyo (M.S.)
| | - Hideyuki Kinoshita
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
| | - Kenji Moriuchi
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
| | | | - Toshio Nishikimi
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
- Wakakusa Tatsuma Rehabilitation Hospital, Osaka (T. Nishikimi)
| | - Hirohiko Motoki
- Cardiovascular Medicine (K.K., M.O., H.M.), School of Medicine, Shinshu University, Matsumoto
| | - Mitsuhiko Yamada
- Molecular Pharmacology (T.N.-T., M.Y.), School of Medicine, Shinshu University, Matsumoto
| | - Sachio Morimoto
- School of Health Sciences Fukuoka, International University of Health and Welfare, Okawa (S.M.)
| | - Kinya Otsu
- The School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Excellence, United Kingdom (K.O.)
| | | | - Kazuwa Nakao
- Medical Innovation Center (K.N.), Graduate School of Medicine, Kyoto University
| | - Takeshi Kimura
- Cardiovascular Medicine (H.I., Y.N., H.K., K.M., H.Y., T. Nishikimi, T. Kimura), Graduate School of Medicine, Kyoto University
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8
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Molina-Holgado E, Paniagua-Torija B, Arevalo-Martin A, Moreno-Luna R, Esteban PF, Le MQU, Del Cerro MDM, Garcia-Ovejero D. Cannabinoid Receptor 1 associates to different molecular complexes during GABAergic neuron maturation. J Neurochem 2021; 158:640-656. [PMID: 33942314 DOI: 10.1111/jnc.15381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/13/2021] [Accepted: 04/29/2021] [Indexed: 01/08/2023]
Abstract
CB1 cannabinoid receptor is widely expressed in the central nervous system of animals from late prenatal development to adulthood. Appropriate activation and signaling of CB1 cannabinoid receptors in cortical interneurons are crucial during perinatal/postnatal ages and adolescence, when long-lasting changes in brain activity may elicit subsequent appearance of disorders in the adult brain. Here we used an optimized immunoprecipitation protocol based on specific antibodies followed by shot-gun proteomics to find CB1 interacting partners in postnatal rat GABAergic cortical neurons in vitro at two different stages of maturation. Besides describing new proteins associated with CB1 like dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex (DLAT), fatty acid synthase (FASN), tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), voltage-dependent anion channel 1 (VDAC1), myosin phosphatase Rho-interacting protein (MPRIP) or usher syndrome type-1C protein-binding protein 1 (USHBP1), we show that the signaling complex of CB1 is different between maturational stages. Interestingly, the CB1 signaling complex is enriched at the more immature stage in mitochondrial associated proteins and metabolic molecular functions, whereas at more mature stage, CB1 complex is increased in maturation and synaptic-associated proteins. We describe also interacting partners specifically immunoprecipitated with either N-terminal or C-terminal CB1 directed antibodies. Our results highlight new players that may be affected by altered cannabinoid signaling at this critical window of postnatal cortical development.
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Affiliation(s)
- Eduardo Molina-Holgado
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
| | | | - Angel Arevalo-Martin
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
| | - Rafael Moreno-Luna
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
| | - Pedro F Esteban
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
| | - Minh Quynh Uyen Le
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
| | | | - Daniel Garcia-Ovejero
- Laboratory of Neuroinflammation, Hospital Nacional de Paraplejicos (SESCAM), Toledo, Spain
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9
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Zhang XB, Li J, Gu J, Zeng YQ. Roles of Cannabidiol in the treatment and prevention of Alzheimer's disease by multi-target actions. Mini Rev Med Chem 2021; 22:43-51. [PMID: 33797364 DOI: 10.2174/1389557521666210331162857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/03/2020] [Accepted: 01/04/2021] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is one of the most common neurodegenerative diseases with chronic, progressive, and irreversible characteristics, affecting nearly 50 million older adults worldwide. The pathogenesis of AD includes the formation of senile plaques, the abnormal aggregation of tau protein and the gradual degeneration and death of cerebral cortical cells. The main symptoms are memory loss, cognitive decline and behavioral disorders. Studies indicate that cannabidiol(CBD) possesses various pharmacological activities including anti-inflammatory, anti-oxidation and neuroprotective activities. It has been suggested as a potential multi-target medicine for treatment of AD. In this review, we aim to summarize the underlying mechanisms and protective effects of CBD on signaling pathways and central receptors involved in the pathogenesis of AD, including the endocannabinoid system(eCBs), the Transient receptor potential vanilloid type 1(TRPV1) receptor, and the Peroxisome proliferator-activated receptor (PPAR) receptor.
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Affiliation(s)
- Xiao-Bei Zhang
- Yunnan Key Laboratory of Stem Cells and Regenerative Medicine, Biomedical Engineering Research Center, Kunming Medical University, Kunming 650500. China
| | - Jintao Li
- School of Basic Medical Sciences, Kunming Medical University, Kunming 650500. China
| | - Juanhua Gu
- Yunnan Key Laboratory of Stem Cells and Regenerative Medicine, Biomedical Engineering Research Center, Kunming Medical University, Kunming 650500. China
| | - Yue-Qin Zeng
- Yunnan Key Laboratory of Stem Cells and Regenerative Medicine, Biomedical Engineering Research Center, Kunming Medical University, Kunming 650500. China
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10
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Li H, Liu Y, Tian D, Tian L, Ju X, Qi L, Wang Y, Liang C. Overview of cannabidiol (CBD) and its analogues: Structures, biological activities, and neuroprotective mechanisms in epilepsy and Alzheimer's disease. Eur J Med Chem 2020; 192:112163. [PMID: 32109623 DOI: 10.1016/j.ejmech.2020.112163] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 01/05/2023]
Abstract
Herein, 11 general types of natural cannabinoids from Cannabis sativa as well as 50 (-)-CBD analogues with therapeutic potential were described. The underlying molecular mechanisms of CBD as a therapeutic candidate for epilepsy and neurodegenerative diseases were comprehensively clarified. CBD indirectly acts as an endogenous cannabinoid receptor agonist to exert its neuroprotective effects. CBD also promotes neuroprotection through different signal transduction pathways mediated indirectly by cannabinoid receptors. Furthermore, CBD prevents the glycogen synthase kinase 3β (GSK-3β) hyperphosphorylation caused by Aβ and may be developed as a new therapeutic candidate for Alzheimer's disease.
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Affiliation(s)
- Han Li
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Yuzhi Liu
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Danni Tian
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Lei Tian
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Xingke Ju
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Liang Qi
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Yongbo Wang
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Chengyuan Liang
- School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China.
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11
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Rossi M, Zhu L, McMillin SM, Pydi SP, Jain S, Wang L, Cui Y, Lee RJ, Cohen AH, Kaneto H, Birnbaum MJ, Ma Y, Rotman Y, Liu J, Cyphert TJ, Finkel T, McGuinness OP, Wess J. Hepatic Gi signaling regulates whole-body glucose homeostasis. J Clin Invest 2018; 128:746-759. [PMID: 29337301 PMCID: PMC5785257 DOI: 10.1172/jci94505] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 11/17/2017] [Indexed: 01/12/2023] Open
Abstract
An increase in hepatic glucose production (HGP) is a key feature of type 2 diabetes. Excessive signaling through hepatic Gs-linked glucagon receptors critically contributes to pathologically elevated HGP. Here, we tested the hypothesis that this metabolic impairment can be counteracted by enhancing hepatic Gi signaling. Specifically, we used a chemogenetic approach to selectively activate Gi-type G proteins in mouse hepatocytes in vivo. Unexpectedly, activation of hepatic Gi signaling triggered a pronounced increase in HGP and severely impaired glucose homeostasis. Moreover, increased Gi signaling stimulated glucose release in human hepatocytes. A lack of functional Gi-type G proteins in hepatocytes reduced blood glucose levels and protected mice against the metabolic deficits caused by the consumption of a high-fat diet. Additionally, we delineated a signaling cascade that links hepatic Gi signaling to ROS production, JNK activation, and a subsequent increase in HGP. Taken together, our data support the concept that drugs able to block hepatic Gi-coupled GPCRs may prove beneficial as antidiabetic drugs.
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Affiliation(s)
- Mario Rossi
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Lu Zhu
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Sara M. McMillin
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Sai Prasad Pydi
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Shanu Jain
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Lei Wang
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Yinghong Cui
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Regina J. Lee
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Amanda H. Cohen
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
| | - Hideaki Kaneto
- Osaka University Graduate School of Medicine, Osaka, Japan
| | - Morris J. Birnbaum
- Cardiovascular and Metabolic Diseases (CVMED), Pfizer Inc., Cambridge, Massachusetts, USA
| | - Yanling Ma
- Liver and Energy Metabolism Unit, Liver Diseases Branch, NIDDK, Bethesda, Maryland, USA
| | - Yaron Rotman
- Liver and Energy Metabolism Unit, Liver Diseases Branch, NIDDK, Bethesda, Maryland, USA
| | - Jie Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, Maryland, USA
| | - Travis J. Cyphert
- Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Toren Finkel
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute (NHLBI), Bethesda, Maryland, USA
| | - Owen P. McGuinness
- Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, Maryland, USA
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12
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Abstract
The CB1 and CB2 cannabinoid receptors (CB1R, CB2R) are members of the G protein-coupled receptor (GPCR) family that were identified over 20 years ago. CB1Rs and CB2Rs mediate the effects of Δ9-tetrahydrocannabinol (Δ9-THC), the principal psychoactive constituent of marijuana, and subsequently identified endogenous cannabinoids (endocannabinoids) anandamide and 2-arachidonoyl glycerol. CB1Rs and CB2Rs have both similarities and differences in their pharmacology. Both receptors recognize multiple classes of agonist and antagonist compounds and produce an array of distinct downstream effects. Natural polymorphisms and alternative splice variants may also contribute to their pharmacological diversity. As our knowledge of the distinct differences grows, we may be able to target select receptor conformations and their corresponding pharmacological responses. This chapter will discuss their pharmacological characterization, distribution, phylogeny, and signaling pathways. In addition, the effects of extended agonist exposure and how that affects signaling and expression patterns of the receptors are considered.
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MESH Headings
- Alternative Splicing/genetics
- Animals
- Humans
- Phylogeny
- Polymorphism, Genetic
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/genetics
- Receptor, Cannabinoid, CB2/metabolism
- Signal Transduction/drug effects
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Affiliation(s)
- Allyn C Howlett
- Center for Research on Substance Use and Addiction, Wake Forest University Health Sciences, Winston-Salem, NC, United States
| | - Mary E Abood
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.
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13
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The Function of FGFR1 Signalling in the Spinal Cord: Therapeutic Approaches Using FGFR1 Ligands after Spinal Cord Injury. Neural Plast 2017; 2017:2740768. [PMID: 28197342 PMCID: PMC5286530 DOI: 10.1155/2017/2740768] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/25/2016] [Indexed: 11/24/2022] Open
Abstract
Extensive research is ongoing that concentrates on finding therapies to enhance CNS regeneration after spinal cord injury (SCI) and to cure paralysis. This review sheds light on the role of the FGFR pathway in the injured spinal cord and discusses various therapies that use FGFR activating ligands to promote regeneration after SCI. We discuss studies that use peripheral nerve grafts or Schwann cell grafts in combination with FGF1 or FGF2 supplementation. Most of these studies show evidence that these therapies successfully enhance axon regeneration into the graft. Further they provide evidence for partial recovery of sensory function shown by electrophysiology and motor activity evidenced by behavioural data. We also present one study that indicates that combination with additional, synergistic factors might further drive the system towards functional regeneration. In essence, this review summarises the potential of nerve and cell grafts combined with FGF1/2 supplementation to improve outcome even after severe spinal cord injury.
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14
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Nakajima KI, Marunaka Y. Intracellular chloride ion concentration in differentiating neuronal cell and its role in growing neurite. Biochem Biophys Res Commun 2016; 479:338-342. [DOI: 10.1016/j.bbrc.2016.09.075] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/15/2016] [Indexed: 02/07/2023]
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15
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Yu Y, Huang Z, Mao Z, Zhang Y, Jin M, Chen W, Zhang W, Yu B, Zhang W, Alaster Lau HY. Go is required for the release of IL-8 and TNF-α, but not degranulation in human mast cells. Eur J Pharmacol 2016; 780:115-21. [PMID: 27025291 DOI: 10.1016/j.ejphar.2016.03.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 03/13/2016] [Accepted: 03/23/2016] [Indexed: 01/16/2023]
Abstract
Mast cells activated by IgE-dependent and -independent mechanisms play important roles in innate and acquired immune responses. Activation of pertussis toxin (PTX)-sensitive Gi/o proteins is the key step in mast cell degranulation and release of de novo synthesized inflammatory mediators through IgE-independent mechanism. However, the roles of Gi and Go proteins in mast cells activation have not yet been differentiated. In the current study, the functional roles of Go proteins in the activities of LAD2 cells, a human mast cell line, are identified. Knockdown of Gαo expression significantly inhibited the synthesis of IL-8 and TNF-α from substance P activated LAD2 cells but demonstrated no effect on degranulation. This effect was associated with the activation of Erk and JNK/MAPKs signaling, whereas PI3K-Akt, calcium mobilization and NFAT translocation remained unchanged. These results suggest that Gi and Go proteins differentially regulate human mast cells activities through activating distinct signaling cascades.
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Affiliation(s)
- Yangyang Yu
- School of medicine, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Zhenhe Huang
- Department of Geriatrics, The Sixth People's Hospital of Shenzhen, Guangdong Province, China
| | - Zhuo Mao
- School of medicine, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Yarui Zhang
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Guangdong Province, China
| | - Meiling Jin
- School of medicine, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Wenwen Chen
- School of medicine, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Wei Zhang
- Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Guangdong Province, China
| | - Bo Yu
- Department of Dermatology, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China.
| | - Weizhen Zhang
- School of medicine, Shenzhen University, Shenzhen, Guangdong Province 518060, China.
| | - Hang Yung Alaster Lau
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
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16
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Haenzi B, Gers-Barlag K, Akhoundzadeh H, Hutson TH, Menezes SC, Bunge MB, Moon LDF. Overexpression of the Fibroblast Growth Factor Receptor 1 (FGFR1) in a Model of Spinal Cord Injury in Rats. PLoS One 2016; 11:e0150541. [PMID: 27015635 PMCID: PMC4807820 DOI: 10.1371/journal.pone.0150541] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/15/2016] [Indexed: 01/03/2023] Open
Abstract
Spinal cord injury (SCI) is a severe condition that affects many people and results in high health care costs. Therefore, it is essential to find new targets for treatment. The fibroblast growth factor receptor 1 (FGFR1) signalling pathway has a history of being explored for SCI treatment. Several groups have examined the effect of high availability of different FGFR1 ligands at the injury site and reported corticospinal tract (CST) regeneration as well as improved motor functions. In this study, we investigated overexpression of the FGFR1 in rat corticospinal neurons in vivo after injury (unilateral pyramidotomy) and in cerebellar granule neurons (CGNs) in vitro. We show that overexpression of FGFR1 using AAV1 intracortical injections did not increase sprouting of the treated corticospinal tract and did not improve dexterity or walking in a rat model of SCI. Furthermore, we show that overexpression of FGFR1 in vitro resulted in decreased neurite outgrowth compared to control. Thus, our results suggest that the FGFR1 is not a suitable therapeutic target after SCI.
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Affiliation(s)
- Barbara Haenzi
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
- * E-mail:
| | - Katharina Gers-Barlag
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
| | - Halima Akhoundzadeh
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
| | - Thomas H. Hutson
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
| | - Sean C. Menezes
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
| | - Mary Bartlett Bunge
- Miami Project to Cure Paralysis, Departments of Cell Biology, Neurological Surgery and Neurology, University of Miami Miller School of Medicine, Miami, FL, 33136, United States of America
| | - Lawrence D. F. Moon
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, SE1 1UL, United Kingdom
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17
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Njoo C, Agarwal N, Lutz B, Kuner R. The Cannabinoid Receptor CB1 Interacts with the WAVE1 Complex and Plays a Role in Actin Dynamics and Structural Plasticity in Neurons. PLoS Biol 2015; 13:e1002286. [PMID: 26496209 PMCID: PMC4619884 DOI: 10.1371/journal.pbio.1002286] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 09/24/2015] [Indexed: 12/25/2022] Open
Abstract
The molecular composition of the cannabinoid type 1 (CB1) receptor complex beyond the classical G-protein signaling components is not known. Using proteomics on mouse cortex in vivo, we pulled down proteins interacting with CB1 in neurons and show that the CB1 receptor assembles with multiple members of the WAVE1 complex and the RhoGTPase Rac1 and modulates their activity. Activation levels of CB1 receptor directly impacted on actin polymerization and stability via WAVE1 in growth cones of developing neurons, leading to their collapse, as well as in synaptic spines of mature neurons, leading to their retraction. In adult mice, CB1 receptor agonists attenuated activity-dependent remodeling of dendritic spines in spinal cord neurons in vivo and suppressed inflammatory pain by regulating the WAVE1 complex. This study reports novel signaling mechanisms for cannabinoidergic modulation of the nervous system and demonstrates a previously unreported role for the WAVE1 complex in therapeutic applications of cannabinoids. A proteomic study reveals the actin nucleation complex WAVE1 as a hitherto unknown binding partner of cannabinoid receptor 1 and explores the functional role of this interaction in regulating pain-related structural plasticity. One of the most interesting features of the endocannabinoid system (a group of neuromodulatory lipids and their receptors, which promotes homeostasis in a variety of physiological processes) is its ability to counteract nociception or pain. This function is largely mediated by the receptor component of the endocannabinoid system. One of the most-studied types of cannabinoid receptors, the cannabinoid receptor 1 (CB1R), exerts its antinociceptive function at all levels of the central nervous system, from the periphery up to the brain. Despite numerous studies on the role of CB1R and its antinociceptive effect, our knowledge of the molecular mechanisms underlying this particular feature is still lacking. In this study, we identify the WAVE1-complex—known to be involved in actin nucleation—as novel interacting partners of CB1R. We observe a functional relationship between the WAVE1-complex and CB1R in the regulation of actin filaments in developing as well as mature cultured neurons. Furthermore, we show that inflammation-induced structural plasticity in spinal neurons that contributes to hyperalgesia is regulated by CB1R in a WAVE1-dependent fashion. These findings expand our understanding of CB1R signaling and of the physiological as well as pathological context of pain.
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MESH Headings
- Actin Cytoskeleton/drug effects
- Actin Cytoskeleton/metabolism
- Animals
- COS Cells
- Cannabinoids/pharmacology
- Cells, Cultured
- Chlorocebus aethiops
- Dendritic Spines/drug effects
- Dendritic Spines/metabolism
- Embryo, Mammalian/cytology
- Frontal Lobe/cytology
- Frontal Lobe/drug effects
- Frontal Lobe/metabolism
- Growth Cones/drug effects
- Growth Cones/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Nerve Tissue Proteins/agonists
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurogenesis/drug effects
- Neuronal Plasticity/drug effects
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Parietal Lobe/cytology
- Parietal Lobe/drug effects
- Parietal Lobe/metabolism
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/metabolism
- Wiskott-Aldrich Syndrome Protein, Neuronal/metabolism
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Affiliation(s)
- Christian Njoo
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Nitin Agarwal
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Rohini Kuner
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
- * E-mail:
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18
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AKT-independent Reelin signaling requires interactions of heterotrimeric Go and Src. Biochem Biophys Res Commun 2015; 467:1063-9. [PMID: 26441085 DOI: 10.1016/j.bbrc.2015.09.167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 09/30/2015] [Indexed: 11/23/2022]
Abstract
Reelin, a large secreted extracellular matrix glycoprotein, plays a key role in neuronal migration during cortical development and promotes neuronal maturation. The signaling pathway regulating neuronal maturation in the postnatal period are relatively less well understood. In this study, we demonstrated that a heterotrimeric G protein, Go, is a novel target of Reelin-induced signaling to promote neurite outgrowth. In primary hippocampal neurons of Reelin-deficient reeler mice, neurite outgrowth was significantly reduced and rescued upon addition of Reelin. Pertussis toxin (PTX) treatment or transfection with Gαo-siRNA suppressed Reelin-mediated neurite outgrowth in wild-type neurons. Additionally, Reelin treatment led to increased phosphorylation of AKT, GSK3β, and JNK, which were all effectively blocked by the PI3K inhibitor, LY294002. By comparison, PTX specifically blocked JNK activation, but not AKT and GSK3β. Immunoprecipitation assays disclosed that Reelin increases the active forms of both Src and Gαo and promotes their direct association. Notably, Dab1, a cytoplasmic adaptor molecule that mediates Reelin signaling, did not interact with Gαo. Neurite outgrowth by Reelin was induced via activating Src kinase, which directly stimulated Gαo, activity, leading to JNK activation. Based on the collective findings, we suggest that Reelin-dependent signaling mechanisms may be split into Src-AKT-dependent and Src-Go-dependent pathways. Our results additionally provide evidence that Reelin receptors cross-communicate with heterologous G protein-coupled receptors (GPCR) independently of the cognate ligands of GPCR.
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19
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Sierra-Fonseca JA, Najera O, Martinez-Jurado J, Walker EM, Varela-Ramirez A, Khan AM, Miranda M, Lamango NS, Roychowdhury S. Nerve growth factor induces neurite outgrowth of PC12 cells by promoting Gβγ-microtubule interaction. BMC Neurosci 2014; 15:132. [PMID: 25552352 PMCID: PMC4302597 DOI: 10.1186/s12868-014-0132-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 11/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Assembly and disassembly of microtubules (MTs) is critical for neurite outgrowth and differentiation. Evidence suggests that nerve growth factor (NGF) induces neurite outgrowth from PC12 cells by activating the receptor tyrosine kinase, TrkA. G protein-coupled receptors (GPCRs) as well as heterotrimeric G proteins are also involved in regulating neurite outgrowth. However, the possible connection between these pathways and how they might ultimately converge to regulate the assembly and organization of MTs during neurite outgrowth is not well understood. RESULTS Here, we report that Gβγ, an important component of the GPCR pathway, is critical for NGF-induced neuronal differentiation of PC12 cells. We have found that NGF promoted the interaction of Gβγ with MTs and stimulated MT assembly. While Gβγ-sequestering peptide GRK2i inhibited neurite formation, disrupted MTs, and induced neurite damage, the Gβγ activator mSIRK stimulated neurite outgrowth, which indicates the involvement of Gβγ in this process. Because we have shown earlier that prenylation and subsequent methylation/demethylation of γ subunits are required for the Gβγ-MTs interaction in vitro, small-molecule inhibitors (L-28 and L-23) targeting prenylated methylated protein methyl esterase (PMPMEase) were tested in the current study. We found that these inhibitors disrupted Gβγ and ΜΤ organization and affected cellular morphology and neurite outgrowth. In further support of a role of Gβγ-MT interaction in neuronal differentiation, it was observed that overexpression of Gβγ in PC12 cells induced neurite outgrowth in the absence of added NGF. Moreover, overexpressed Gβγ exhibited a pattern of association with MTs similar to that observed in NGF-differentiated cells. CONCLUSIONS Altogether, our results demonstrate that βγ subunit of heterotrimeric G proteins play a critical role in neurite outgrowth and differentiation by interacting with MTs and modulating MT rearrangement.
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Affiliation(s)
- Jorge A Sierra-Fonseca
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
- />Present Address: Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Omar Najera
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Jessica Martinez-Jurado
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Ellen M Walker
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Armando Varela-Ramirez
- />Cytometry Screening and Imaging Core facility, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Arshad M Khan
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Manuel Miranda
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
| | - Nazarius S Lamango
- />College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307 USA
| | - Sukla Roychowdhury
- />Neuromodulation Disorders Cluster, Border Biomedical Research Center, University of Texas, El Paso, TX 79968 USA
- />Department of Biological Sciences, University of Texas, El Paso, TX 79968 USA
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20
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Franks LN, Ford BM, Madadi NR, Penthala NR, Crooks PA, Prather PL. Characterization of the intrinsic activity for a novel class of cannabinoid receptor ligands: Indole quinuclidine analogs. Eur J Pharmacol 2014; 737:140-8. [PMID: 24858620 DOI: 10.1016/j.ejphar.2014.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/23/2014] [Accepted: 05/06/2014] [Indexed: 12/16/2022]
Abstract
Our laboratory recently reported that a group of novel indole quinuclidine analogs bind with nanomolar affinity to cannabinoid type-1 and type-2 receptors. This study characterized the intrinsic activity of these compounds by determining whether they exhibit agonist, antagonist, or inverse agonist activity at cannabinoid type-1 and/or type-2 receptors. Cannabinoid receptors activate Gi/Go-proteins that then proceed to inhibit activity of the downstream intracellular effector adenylyl cyclase. Therefore, intrinsic activity was quantified by measuring the ability of compounds to modulate levels of intracellular cAMP in intact cells. Concerning cannabinoid type-1 receptors endogenously expressed in Neuro2A cells, a single analog exhibited agonist activity, while eight acted as neutral antagonists and two possessed inverse agonist activity. For cannabinoid type-2 receptors stably expressed in CHO cells, all but two analogs acted as agonists; these two exceptions exhibited inverse agonist activity. Confirming specificity at cannabinoid type-1 receptors, modulation of adenylyl cyclase activity by all proposed agonists and inverse agonists was blocked by co-incubation with the neutral cannabinoid type-1 antagonist O-2050. All proposed cannabinoid type-1 receptor antagonists attenuated adenylyl cyclase modulation by cannabinoid agonist CP-55,940. Specificity at cannabinoid type-2 receptors was confirmed by failure of all compounds to modulate adenylyl cyclase activity in CHO cells devoid of cannabinoid type-2 receptors. Further characterization of select analogs demonstrated concentration-dependent modulation of adenylyl cyclase activity with potencies similar to their respective affinities for cannabinoid receptors. Therefore, indole quinuclidines are a novel structural class of compounds exhibiting high affinity and a range of intrinsic activity at cannabinoid type-1 and type-2 receptors.
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MESH Headings
- Adenylyl Cyclase Inhibitors
- Adenylyl Cyclases/metabolism
- Animals
- CHO Cells
- Chemical Phenomena
- Cricetinae
- Cricetulus
- Drug Inverse Agonism
- Humans
- Indoles/chemistry
- Ligands
- Mice
- Quinuclidines/chemistry
- Quinuclidines/metabolism
- Quinuclidines/pharmacology
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/agonists
- Receptor, Cannabinoid, CB2/antagonists & inhibitors
- Receptor, Cannabinoid, CB2/metabolism
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Affiliation(s)
- Lirit N Franks
- Department of Pharmacology & Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
| | - Benjamin M Ford
- Department of Pharmacology & Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
| | - Nikhil R Madadi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
| | - Narsimha R Penthala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
| | - Peter A Crooks
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
| | - Paul L Prather
- Department of Pharmacology & Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205, USA.
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21
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Hultman R, Kumari U, Michel N, Casey PJ. Gαz regulates BDNF-induction of axon growth in cortical neurons. Mol Cell Neurosci 2013; 58:53-61. [PMID: 24321455 DOI: 10.1016/j.mcn.2013.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 11/27/2013] [Accepted: 12/03/2013] [Indexed: 01/26/2023] Open
Abstract
The disruption of neurotransmitter and neurotrophic factor signaling in the central nervous system (CNS) is implicated as the root cause of neuropsychiatric disorders, including schizophrenia, epilepsy, chronic pain, and depression. Therefore, identifying the underlying molecular mechanisms by which neurotransmitter and neurotrophic factor signaling regulates neuronal survival or growth may facilitate identification of more effective therapies for these disorders. Previously, our lab found that the heterotrimeric G protein, Gz, mediates crosstalk between G protein-coupled receptors and neurotrophin signaling in the neural cell line PC12. These data, combined with Gαz expression profiles--predominantly in neuronal cells with higher expression levels corresponding to developmental times of target tissue innervation--suggested that Gαz may play an important role in neurotrophin signaling and neuronal development. Here, we provide evidence in cortical neurons, both manipulated ex vivo and those cultured from Gz knockout mice, that Gαz is localized to axonal growth cones and plays a significant role in the development of axons of cortical neurons in the CNS. Our findings indicate that Gαz inhibits BDNF-stimulated axon growth in cortical neurons, establishing an endogenous role for Gαz in regulating neurotrophin signaling in the CNS.
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Affiliation(s)
- Rainbo Hultman
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA; Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Republic of Singapore
| | - Udhaya Kumari
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Republic of Singapore
| | - Nadine Michel
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA
| | - Patrick J Casey
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA; Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Republic of Singapore.
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22
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Nakamura T, Yasuda S, Nagai H, Koinuma S, Morishita S, Goto A, Kinashi T, Wada N. Longest neurite-specific activation of Rap1B in hippocampal neurons contributes to polarity formation through RalA and Nore1A in addition to PI3-kinase. Genes Cells 2013; 18:1020-31. [DOI: 10.1111/gtc.12097] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 08/13/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Takeshi Nakamura
- Division of Biosignaling, Research Institute for Biomedical Sciences; Tokyo University of Science; Noda Chiba 278-0022 Japan
| | - Sayaka Yasuda
- Division of Biosignaling, Research Institute for Biomedical Sciences; Tokyo University of Science; Noda Chiba 278-0022 Japan
| | - Hiroyuki Nagai
- Division of Biosignaling, Research Institute for Biomedical Sciences; Tokyo University of Science; Noda Chiba 278-0022 Japan
| | - Shingo Koinuma
- Division of Biosignaling, Research Institute for Biomedical Sciences; Tokyo University of Science; Noda Chiba 278-0022 Japan
| | - So Morishita
- Division of Biosignaling, Research Institute for Biomedical Sciences; Tokyo University of Science; Noda Chiba 278-0022 Japan
- Department of Applied Biological Science; Tokyo University of Science; Noda Chiba 278-8510 Japan
| | - Akihiro Goto
- Laboratory of Bioimaging and Cell Signaling; Graduate School of Biostudies; Kyoto University; Kyoto 606-8501 Japan
| | - Tatsuo Kinashi
- Department of Molecular Genetics; Kansai Medical University; Osaka 573-1010 Japan
| | - Naoyuki Wada
- Department of Applied Biological Science; Tokyo University of Science; Noda Chiba 278-8510 Japan
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23
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Georganta EM, Tsoutsi L, Gaitanou M, Georgoussi Z. δ-opioid receptor activation leads to neurite outgrowth and neuronal differentiation via a STAT5B-Gαi/o pathway. J Neurochem 2013; 127:329-41. [DOI: 10.1111/jnc.12386] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/27/2013] [Accepted: 07/29/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Eirini-Maria Georganta
- Laboratory of Cellular Signalling and Molecular Pharmacology; Institute of Biosciences and Applications; National Centre for Scientific Research “Demokritos”; Athens Greece
| | - Lambrini Tsoutsi
- Laboratory of Cellular Signalling and Molecular Pharmacology; Institute of Biosciences and Applications; National Centre for Scientific Research “Demokritos”; Athens Greece
| | - Maria Gaitanou
- Laboratory of Cellular and Molecular Neurobiology; Hellenic Pasteur Institute; Athens Greece
| | - Zafiroula Georgoussi
- Laboratory of Cellular Signalling and Molecular Pharmacology; Institute of Biosciences and Applications; National Centre for Scientific Research “Demokritos”; Athens Greece
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24
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Amyloid precursor proteins interact with the heterotrimeric G protein Go in the control of neuronal migration. J Neurosci 2013; 33:10165-81. [PMID: 23761911 DOI: 10.1523/jneurosci.1146-13.2013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Amyloid precursor protein (APP) belongs to a family of evolutionarily conserved transmembrane glycoproteins that has been proposed to regulate multiple aspects of cell motility in the nervous system. Although APP is best known as the source of β-amyloid fragments (Aβ) that accumulate in Alzheimer's disease, perturbations affecting normal APP signaling events may also contribute to disease progression. Previous in vitro studies showed that interactions between APP and the heterotrimeric G protein Goα-regulated Goα activity and Go-dependent apoptotic responses, independent of Aβ. However, evidence for authentic APP-Go interactions within the healthy nervous system has been lacking. To address this issue, we have used a combination of in vitro and in vivo strategies to show that endogenously expressed APP family proteins colocalize with Goα in both insect and mammalian nervous systems, including human brain. Using biochemical, pharmacological, and Bimolecular Fluorescence Complementation assays, we have shown that insect APP (APPL) directly interacts with Goα in cell culture and at synaptic terminals within the insect brain, and that this interaction is regulated by Goα activity. We have also adapted a well characterized assay of neuronal migration in the hawkmoth Manduca to show that perturbations affecting APPL and Goα signaling induce the same unique pattern of ectopic, inappropriate growth and migration, analogous to defective migration patterns seen in mice lacking all APP family proteins. These results support the model that APP and its orthologs regulate conserved aspects of neuronal migration and outgrowth in the nervous system by functioning as unconventional Goα-coupled receptors.
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25
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Dalton GD, Peterson LJ, Howlett AC. CB₁ cannabinoid receptors promote maximal FAK catalytic activity by stimulating cooperative signaling between receptor tyrosine kinases and integrins in neuronal cells. Cell Signal 2013; 25:1665-77. [PMID: 23571270 PMCID: PMC4165595 DOI: 10.1016/j.cellsig.2013.03.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 03/16/2013] [Accepted: 03/26/2013] [Indexed: 01/28/2023]
Abstract
Tyrosine phosphorylation (Tyr-P) of focal adhesion kinase (FAK) regulates FAK activation. Phosphorylated FAK Tyr 397 binds Src family kinases (Src), which in turn directly phosphorylate FAK Tyr 576/577 to produce maximal FAK enzymatic activity. CB₁ cannabinoid receptors (CB₁) are abundantly expressed in the nervous system and influence FAK activation by presently unknown mechanisms. The current investigation determined that CB₁-stimulated maximal FAK catalytic activity is mediated by Gi/o proteins in N18TG2 neuronal cells, and that G12/13 regulation of Rac1 and RhoA occurs concomitantly. Immunoblotting analyses using antibodies against FAK phospho-Tyr 397 and phospho-Tyr 576/577 demonstrated that the time-course of CB₁-stimulated FAK 576/577 Tyr-P occurred in three phases: Phase I (0-2 min) maximal Tyr-P, Phase II (5-20 min) rapid decline in Tyr-P, and Phase III (>20 min) plateau in Tyr-P at submaximal levels. In contrast, FAK 397 Tyr-P was monophasic and significantly lower in magnitude. FAK 397 Tyr-P and Phase I FAK 576/577 Tyr-P involved protein tyrosine phosphatase (PTP1B and Shp1/Shp2)-mediated Src activation, Protein Kinase A (PKA) inhibition, and integrin activation. Phase I maximal FAK 576/577 Tyr-P also required cooperative signaling between receptor tyrosine kinases (RTKs) and integrins. The integrin antagonist RGDS peptide, Flk-1 vascular endothelial growth factor receptor (VEGFR) antagonist SU5416, and epidermal growth factor receptor (EGFR) antagonist AG 1478 blocked Phase I FAK 576/577 Tyr-P. CB₁ agonists failed to stimulate FAK Tyr-P in the absence of integrin activation upon suspension in serum-free culture media. In contrast, cells grown on the integrin ligands fibronectin and laminin displayed increased FAK 576/577 Tyr-P that was augmented by CB₁ agonists and blocked by the Src inhibitor PP2 and Flk-1 VEGFR antagonist SU5416. Taken together, these studies have identified a complex integrative pathway utilized by CB₁ to stimulate maximal FAK 576/577 Tyr-P in neuronal cells.
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MESH Headings
- Animals
- Benzoxazines/pharmacology
- Cell Line, Tumor
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/metabolism
- Fibronectins/pharmacology
- Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors
- Focal Adhesion Protein-Tyrosine Kinases/metabolism
- Integrins/antagonists & inhibitors
- Integrins/genetics
- Integrins/metabolism
- Kinetics
- Laminin/pharmacology
- Mice
- Morpholines/pharmacology
- Naphthalenes/pharmacology
- Neurons/cytology
- Neurons/metabolism
- Oligopeptides/pharmacology
- Pertussis Toxin/pharmacology
- Phosphorylation/drug effects
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/antagonists & inhibitors
- Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 11/antagonists & inhibitors
- Protein Tyrosine Phosphatase, Non-Receptor Type 11/metabolism
- Protein Tyrosine Phosphatase, Non-Receptor Type 6/antagonists & inhibitors
- Protein Tyrosine Phosphatase, Non-Receptor Type 6/metabolism
- RNA Interference
- RNA, Small Interfering/metabolism
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/metabolism
- Signal Transduction/drug effects
- Time Factors
- Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors
- Vascular Endothelial Growth Factor Receptor-2/metabolism
- src-Family Kinases/antagonists & inhibitors
- src-Family Kinases/metabolism
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Affiliation(s)
- George D Dalton
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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26
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Cheng YC, Scotting PJ, Hsu LS, Lin SJ, Shih HY, Hsieh FY, Wu HL, Tsao CL, Shen CJ. Zebrafish rgs4 is essential for motility and axonogenesis mediated by Akt signaling. Cell Mol Life Sci 2013; 70:935-50. [PMID: 23052218 PMCID: PMC11113239 DOI: 10.1007/s00018-012-1178-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 12/21/2022]
Abstract
The schizophrenia susceptibility gene, Rgs4, is one of the most intensively studied regulators of G-protein signaling members, well known to be fundamental in regulating neurotransmission. However, little is known about its role in the developing nervous system. We have isolated zebrafish rgs4 and shown that it is transcribed in the developing nervous system. Rgs4 knockdown did not affect neuron number and patterning but resulted in locomotion defects and aberrant development of axons. This was confirmed using a selective Rgs4 inhibitor, CCG-4986. Rgs4 knockdown also attenuated the level of phosphorylated-Akt1, and injection of constitutively-activated AKT1 rescued the motility defects and axonal phenotypes in the spinal cord but not in the hindbrain and trigeminal neurons. Our in vivo analysis reveals a novel role for Rgs4 in regulating axonogenesis during embryogenesis, which is mediated by another schizophrenia-associated gene, Akt1, in a region-specific manner.
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Affiliation(s)
- Yi-Chuan Cheng
- Graduate Institute of Biomedical Sciences, School of Medicine, Chang Gung University, Taoyuan, 33383, Taiwan.
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27
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Baron J, Blex C, Rohrbeck A, Rachakonda SK, Birnbaumer L, Ahnert-Hilger G, Brunk I. The α-subunit of the trimeric GTPase Go2 regulates axonal growth. J Neurochem 2013; 124:782-94. [PMID: 23373526 DOI: 10.1111/jnc.12123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 11/23/2012] [Accepted: 12/09/2012] [Indexed: 11/30/2022]
Abstract
The Goα splice variants Go1α and Go2α are subunits of the most abundant G-proteins in brain, Go1 and Go2. Only a few interacting partners binding to Go1α have been described so far and splice variant-specific differences are not known. Using a yeast two-hybrid screen with constitutively active Go2α as bait, we identified Rap1GTPase activating protein (Rap1GAP) and Girdin as interacting partners of Go2α, which was confirmed by co-immunoprecipitation. Comparison of subcellular fractions from brains of wild type and Go2α-/- mice revealed no differences in the overall expression level of Girdin or Rap1GAP. However, we found higher amounts of active Rap1-GTP in brains of Go2α deficient mutants, indicating that Go2α may increase Rap1GAP activity, thereby effecting the Rap1 activation/deactivation cycle. Rap1 has been shown to be involved in neurite outgrowth and given a Rap1GAP-Go2α interaction, we found that the loss of Go2α affected axonal outgrowth. Axons of cultured cortical and hippocampal neurons prepared from embryonic Go2α-/- mice grew longer and developed more branches than those from wild-type mice. Taken together, we provide evidence that Go2α regulates axonal outgrowth and branching.
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Affiliation(s)
- Jens Baron
- Center for Anatomy, Institute for Integrative Neuroanatomy, Functional Cell Biology, Charité-Universitätsmedizin Berlin, Germany
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28
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Fu Y, Wu X, Lu J, Huang ZJ. Presynaptic GABA(B) Receptor Regulates Activity-Dependent Maturation and Patterning of Inhibitory Synapses through Dynamic Allocation of Synaptic Vesicles. Front Cell Neurosci 2012; 6:57. [PMID: 23227002 PMCID: PMC3512030 DOI: 10.3389/fncel.2012.00057] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 11/12/2012] [Indexed: 11/13/2022] Open
Abstract
Accumulating evidence indicate that GABA regulates activity-dependent development of inhibitory synapses in the vertebrate brain, but the underlying mechanisms remain unclear. Here we combined live imaging of cortical GABAergic axons with single cell genetic manipulation to dissect the role of presynaptic GABAB receptors (GABABRs) in inhibitory synapse formation in mouse. Developing GABAergic axons form a significant number of transient boutons but only a subset was stabilized. Synaptic vesicles in these nascent boutons are often highly mobile in the course of tens of minutes. Activation of presynaptic GABABRs stabilized mobile vesicles in nascent boutons through the local enhancement of actin polymerization. Inactivation of GABABRs in developing basket interneurons resulted in aberrant pattern of bouton size distribution, reduced bouton density and reduced axon branching, as well as reduced frequency of miniature inhibitory currents in postsynaptic pyramidal neurons. These results suggest that GABABRs along developing inhibitory axons act as a local sensor of GABA release and promote presynaptic maturation through increased recruitment of mobile vesicle pools. Such release-dependent validation and maturation of nascent terminals is well suited to sculpt the pattern of synapse formation and distribution along axon branches.
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Affiliation(s)
- Yu Fu
- Cold Spring Harbor Laboratory Cold Spring Harbor, NY, USA ; Program in Neuroscience, Stony Brook University Stony Brook, NY, USA
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29
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Abstract
Painful peripheral neuropathy is a dose-limiting complication of chemotherapy. Cisplatin produces a cumulative toxic effect on peripheral nerves, and 30-40% of cancer patients receiving this agent experience pain. By modeling cisplatin-induced hyperalgesia in mice with daily injections of cisplatin (1 mg/kg, i.p.) for 7 d, we investigated the anti-hyperalgesic effects of anandamide (AEA) and cyclohexylcarbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597), an inhibitor of AEA hydrolysis. Cisplatin-induced mechanical and heat hyperalgesia were accompanied by a decrease in the level of AEA in plantar paw skin. No changes in motor activity were observed after seven injections of cisplatin. Intraplantar injection of AEA (10 μg/10 μl) or URB597 (9 μg/10 μl) transiently attenuated hyperalgesia through activation of peripheral CB₁ receptors. Co-injections of URB597 (0.3 mg/kg daily, i.p.) with cisplatin decreased and delayed the development of mechanical and heat hyperalgesia. The effect of URB597 was mediated by CB₁ receptors since AM281 (0.33 mg/kg daily, i.p.) blocked the effect of URB597. Co-injection of URB597 also normalized the cisplatin-induced decrease in conduction velocity of Aα/Aβ-fibers and reduced the increase of ATF-3 and TRPV1 immunoreactivity in dorsal root ganglion (DRG) neurons. Since DRGs are a primary site of toxicity by cisplatin, effects of cisplatin were studied on cultured DRG neurons. Incubation of DRG neurons with cisplatin (4 μg/ml) for 24 h decreased the total length of neurites. URB597 (100 nM) attenuated these changes through activation of CB₁ receptors. Collectively, these results suggest that pharmacological facilitation of AEA signaling is a promising strategy for attenuating cisplatin-associated sensory neuropathy.
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30
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Bratton MR, Antoon JW, Duong BN, Frigo DE, Tilghman S, Collins-Burow BM, Elliott S, Tang Y, Melnik LI, Lai L, Alam J, Beckman BS, Hill SM, Rowan BG, McLachlan JA, Burow ME. Gαo potentiates estrogen receptor α activity via the ERK signaling pathway. J Endocrinol 2012; 214:45-54. [PMID: 22562654 PMCID: PMC3614348 DOI: 10.1530/joe-12-0097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The estrogen receptor α (ERα) is a transcription factor that mediates the biological effects of 17β-estradiol (E(2)). ERα transcriptional activity is also regulated by cytoplasmic signaling cascades. Here, several Gα protein subunits were tested for their ability to regulate ERα activity. Reporter assays revealed that overexpression of a constitutively active Gα(o) protein subunit potentiated ERα activity in the absence and presence of E(2). Transient transfection of the human breast cancer cell line MCF-7 showed that Gα(o) augments the transcription of several ERα-regulated genes. Western blots of HEK293T cells transfected with ER±Gα(o) revealed that Gα(o) stimulated phosphorylation of ERK 1/2 and subsequently increased the phosphorylation of ERα on serine 118. In summary, our results show that Gα(o), through activation of the MAPK pathway, plays a role in the regulation of ERα activity.
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Affiliation(s)
- Melyssa R Bratton
- Section of Hematology and Medical Oncology, Department of Medicine, Tulane University, 1430 Tulane Avenue, SL-78, New Orleans, Louisiana 70112, USA
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31
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Sadrian B, Cheng TW, Shull O, Gong Q. Rap1gap2 regulates axon outgrowth in olfactory sensory neurons. Mol Cell Neurosci 2012; 50:272-82. [PMID: 22732430 DOI: 10.1016/j.mcn.2012.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/13/2012] [Accepted: 06/14/2012] [Indexed: 12/30/2022] Open
Abstract
Olfactory sensory neurons (OSNs) extend their axons from the nasal epithelium to their odorant receptor-dependent locations in the olfactory bulb. Previous studies have identified several membrane proteins along the projection pathway, and on OSN axons themselves, which regulate this process; however, little is known about the signaling mechanisms through which these factors act. We have identified and characterized Rap1gap2, a novel small GTPase regulator, in OSNs during early postnatal mouse development. Rap1gap2 overexpression limits neurite outgrowth and branching in Neuro-2a cells, and counteracts Rap1-induced augmentation of neurite outgrowth. Rap1gap2 expression is developmentally regulated within OSNs, with high expression in early postnatal stages that ultimately drops to undetectable levels by adulthood. This temporal pattern coincides with an early postnatal plastic period of OSN innervation refinement at the OB glomerular layer. Rap1gap2 stunts OSN axon outgrowth when overexpressed in vitro, while knock-down of Rap1gap2 transcript results in a significant increase in axon length. These results indicate an important role of Rap1gap2 in OSN axon growth dynamics during early postnatal development.
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Affiliation(s)
- Benjamin Sadrian
- Department of Cell Biology and Human Anatomy, University of California, Davis, School of Medicine, Davis, CA 95616, USA.
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32
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Soderstrom K, Zhang Y, Wilson AR. Altered patterns of filopodia production in CHO cells heterologously expressing zebra finch CB(1) cannabinoid receptors. Cell Adh Migr 2012; 6:91-9. [PMID: 22568949 DOI: 10.4161/cam.20164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recent findings indicate that cannabinoid-altered vocal development involves elevated densities of dendritic spines in a subset of brain regions involved in zebra finch song learning and production suggesting that cannabinoid receptor activation may regulate cell structure. Here we report that activation of zebra finch CB 1 receptors (zfCB 1, delivered by a lentivector to CHO cells) produces dose-dependent biphasic effects on the mean length of filopodia expressed: Low agonist concentrations (3 nM WIN55212-2) increase lengths while higher concentrations reduce them. In contrast, treatment of zfCB 1-expressing cells with the antagonist/inverse agonist SR141716A causes increases in both mean filopodia length and number at 30 and 100 nM. These results demonstrate that CB 1 receptor activation can differentially influence filiopodia elongation depending on dose, and demonstrate that manipulation of cannabinoid receptor activity is capable of modulating cell morphology.
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Affiliation(s)
- Ken Soderstrom
- Department of Pharmacology and Toxicology, Brody School of Medicine, East Carolina University, Greenville, NC, USA.
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33
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Ligeti E, Welti S, Scheffzek K. Inhibition and Termination of Physiological Responses by GTPase Activating Proteins. Physiol Rev 2012; 92:237-72. [DOI: 10.1152/physrev.00045.2010] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Physiological processes are strictly organized in space and time. However, in cell physiology research, more attention is given to the question of space rather than to time. To function as a signal, environmental changes must be restricted in time; they need not only be initiated but also terminated. In this review, we concentrate on the role of one specific protein family involved in biological signal termination. GTPase activating proteins (GAPs) accelerate the endogenously low GTP hydrolysis rate of monomeric guanine nucleotide-binding proteins (GNBPs), limiting thereby their prevalence in the active, GTP-bound form. We discuss cases where defective or excessive GAP activity of specific proteins causes significant alteration in the function of the nervous, endocrine, and hemopoietic systems, or contributes to development of infections and tumors. Biochemical and genetic data as well as observations from human pathology support the notion that GAPs represent vital elements in the spatiotemporal fine tuning of physiological processes.
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Affiliation(s)
- Erzsébet Ligeti
- Department of Physiology, Semmelweis University, Budapest, Hungary; Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; and Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Stefan Welti
- Department of Physiology, Semmelweis University, Budapest, Hungary; Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; and Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Klaus Scheffzek
- Department of Physiology, Semmelweis University, Budapest, Hungary; Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; and Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
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34
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Jia L, Linder ME, Blumer KJ. Gi/o signaling and the palmitoyltransferase DHHC2 regulate palmitate cycling and shuttling of RGS7 family-binding protein. J Biol Chem 2011; 286:13695-703. [PMID: 21343290 DOI: 10.1074/jbc.m110.193763] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
R7BP (RGS7 family-binding protein) has been proposed to function in neurons as a palmitoylation-regulated protein that shuttles heterodimeric, G(i/o)α-specific GTPase-activating protein (GAP) complexes composed of Gβ5 and RGS7 (R7) isoforms between the plasma membrane and nucleus. To test this hypothesis we studied R7BP palmitoylation and localization in neuronal cells. We report that R7BP undergoes dynamic, signal-regulated palmitate turnover; the palmitoyltransferase DHHC2 mediates de novo and turnover palmitoylation of R7BP; DHHC2 silencing redistributes R7BP from the plasma membrane to the nucleus; and G(i/o) signaling inhibits R7BP depalmitoylation whereas G(i/o) inactivation induces nuclear accumulation of R7BP. In concert with previous evidence, our findings suggest that agonist-induced changes in palmitoylation state facilitate GAP action by (i) promoting Giα depalmitoylation to create optimal GAP substrates, and (ii) inhibiting R7BP depalmitoylation to stabilize membrane association of R7-Gβ5 GAP complexes. Regulated palmitate turnover may also enable R7BP-bound GAPs to shuttle between sites of low and high G(i/o) activity or the plasma membrane and nucleus, potentially providing spatio-temporal control of signaling by G(i/o)-coupled receptors.
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Affiliation(s)
- Lixia Jia
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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35
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Howlett AC, Blume LC, Dalton GD. CB(1) cannabinoid receptors and their associated proteins. Curr Med Chem 2010; 17:1382-93. [PMID: 20166926 DOI: 10.2174/092986710790980023] [Citation(s) in RCA: 184] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 02/18/2010] [Indexed: 12/22/2022]
Abstract
CB1 receptors are G-protein coupled receptors (GPCRs) abundant in neurons, in which they modulate neurotransmission. The CB(1) receptor influence on memory and learning is well recognized, and disease states associated with CB(1) receptors are observed in addiction disorders, motor dysfunction, schizophrenia, and in bipolar, depression, and anxiety disorders. Beyond the brain, CB(1) receptors also function in liver and adipose tissues, vascular as well as cardiac tissue, reproductive tissues and bone. Signal transduction by CB(1) receptors occurs through interaction with Gi/o proteins to inhibit adenylyl cyclase, activate mitogen-activated protein kinases (MAPK), inhibit voltage-gated Ca(2+) channels, activate K(+) currents (K(ir)), and influence Nitric Oxide (NO) signaling. CB(1) receptors are observed in internal organelles as well as plasma membrane. beta-Arrestins, adaptor protein AP-3, and G-protein receptor-associated sorting protein 1 (GASP1) modulate cellular trafficking. Cannabinoid Receptor Interacting Protein1a (CRIP1a) is an accessory protein whose function has not been delineated. Factor Associated with Neutral sphingomyelinase (FAN) regulates ceramide signaling. Such diversity in cellular signaling and modulation by interacting proteins suggests that agonists and allosteric modulators could be developed to specifically regulate unique, cell type-specific responses.
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Affiliation(s)
- Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest University Health Sciences, Winston-Salem, NC 27157, USA.
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Gandou C, Ohtani A, Senzaki K, Shiga T. Neurotensin promotes the dendrite elongation and the dendritic spine maturation of the cerebral cortex in vitro. Neurosci Res 2010; 66:246-55. [DOI: 10.1016/j.neures.2009.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/16/2009] [Accepted: 11/17/2009] [Indexed: 01/07/2023]
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The role of glial cells in influencing neurite extension by dorsal root ganglion cells. ACTA ACUST UNITED AC 2009; 6:19-29. [PMID: 20025817 DOI: 10.1017/s1740925x09990433] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
When pretreated with pertussis toxin (PTX), the neurites of adult rat dorsal root ganglion (DRG) cells in mixed cell cultures retract over a period of 2 h following the initial stimulus of removal from the cell culture incubator for brief periods of observation. The purpose of this investigation was to determine whether this PTX-dependent response was specific to any one of the three subpopulations of DRG neurons. However, no neurite retraction response was observed in neuron-enriched populations of cells, or in cultures enriched in isolectin B4 (IB4)-positive neurons or in IB4-negative neurons. But, the addition of non-neuronal cells, and/or medium conditioned by non-neuronal cells, was sufficient to restore the PTX-dependent neurite retraction response, but only in large diameter IB4-negative neurons. In conclusion, we have identified a regulatory response, mediated by Gi/o-proteins, which prevents retraction of neurites in large diameter IB4-negative cells of adult rat DRG. The non-neuronal cells of adult rat DRG constitutively release factor/s that can stimulate neurite retraction of a subset of isolated DRG neurons, but this property of non-neuronal cells is only observed when the Gi/o-proteins of large diameter IB4-negative cells are inhibited.
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Abstract
The importance of the second messengers calcium (Ca(2+)) and diacylglycerol (DAG) in platelet signal transduction was established more than 30 years ago. Whereas protein kinase C (PKC) family members were discovered as the targets of DAG, little is known about the molecular identity of the main Ca(2+) sensor(s). We here identify Ca(2+) and DAG-regulated guanine nucleotide exchange factor I (CalDAG-GEFI) as a critical molecule in Ca(2+)-dependent platelet activation. CalDAG-GEFI, through activation of the small GTPase Rap1, directly triggers integrin activation and extracellular signal-regulated kinase-dependent thromboxane A(2) (TxA(2)) release. CalDAG-GEFI-dependent TxA(2) generation provides crucial feedback for PKC activation and granule release, particularly at threshold agonist concentrations. PKC/P2Y12 signaling in turn mediates a second wave of Rap1 activation, necessary for sustained platelet activation and thrombus stabilization. Our results lead to a revised model for platelet activation that establishes one molecule, CalDAG-GEFI, at the nexus of Ca(2+)-induced integrin activation, TxA(2) generation, and granule release. The preferential activation of CalDAG-GEFI over PKC downstream of phospholipase C activation, and the different kinetics of CalDAG-GEFI- and PKC/P2Y12-mediated Rap1 activation demonstrate an unexpected complexity to the platelet activation process, and they challenge the current model that DAG/PKC-dependent signaling events are crucial for the initiation of platelet adhesion.
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Kano M, Ohno-Shosaku T, Hashimotodani Y, Uchigashima M, Watanabe M. Endocannabinoid-mediated control of synaptic transmission. Physiol Rev 2009; 89:309-80. [PMID: 19126760 DOI: 10.1152/physrev.00019.2008] [Citation(s) in RCA: 1048] [Impact Index Per Article: 69.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The discovery of cannabinoid receptors and subsequent identification of their endogenous ligands (endocannabinoids) in early 1990s have greatly accelerated research on cannabinoid actions in the brain. Then, the discovery in 2001 that endocannabinoids mediate retrograde synaptic signaling has opened up a new era for cannabinoid research and also established a new concept how diffusible messengers modulate synaptic efficacy and neural activity. The last 7 years have witnessed remarkable advances in our understanding of the endocannabinoid system. It is now well accepted that endocannabinoids are released from postsynaptic neurons, activate presynaptic cannabinoid CB(1) receptors, and cause transient and long-lasting reduction of neurotransmitter release. In this review, we aim to integrate our current understanding of functions of the endocannabinoid system, especially focusing on the control of synaptic transmission in the brain. We summarize recent electrophysiological studies carried out on synapses of various brain regions and discuss how synaptic transmission is regulated by endocannabinoid signaling. Then we refer to recent anatomical studies on subcellular distribution of the molecules involved in endocannabinoid signaling and discuss how these signaling molecules are arranged around synapses. In addition, we make a brief overview of studies on cannabinoid receptors and their intracellular signaling, biochemical studies on endocannabinoid metabolism, and behavioral studies on the roles of the endocannabinoid system in various aspects of neural functions.
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Affiliation(s)
- Masanobu Kano
- Department of Neurophysiology, The University of Tokyo, Tokyo, Japan.
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Dave RH, Saengsawang W, Yu JZ, Donati R, Rasenick MM. Heterotrimeric G-proteins interact directly with cytoskeletal components to modify microtubule-dependent cellular processes. Neurosignals 2009; 17:100-8. [PMID: 19212143 DOI: 10.1159/000186693] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 11/05/2008] [Indexed: 01/07/2023] Open
Abstract
A large percentage of current drugs target G-protein-coupled receptors, which couple to well-known signaling pathways involving cAMP or calcium. G-proteins themselves may subserve a second messenger function. Here, we review the role of tubulin and microtubules in directly mediating effects of heterotrimeric G-proteins on neuronal outgrowth, shape and differentiation. G-protein-tubulin interactions appear to be regulated by neurotransmitter activity, and, in turn, regulate the location of Galpha in membrane microdomains (such as lipid rafts) or the cytosol. Tubulin binds with nanomolar affinity to Gsalpha, Gialpha1 and Gqalpha (but not other Galpha subunits) as well as Gbeta(1)gamma(2) subunits. Galpha subunits destabilize microtubules by stimulating tubulin's GTPase, while Gbetagamma subunits promote microtubule stability. The same region on Gsalpha that binds adenylyl cyclase and Gbetagamma also interacts with tubulin, suggesting that cytoskeletal proteins are novel Galpha effectors. Additionally, intracellular Gialpha-GDP, in concert with other GTPase proteins and Gbetagamma, regulates the position of the mitotic spindle in mitosis. Thus, G-protein activation modulates cell growth and differentiation by directly altering microtubule stability. Further studies are needed to fully establish a structural mechanism of this interaction and its role in synaptic plasticity.
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Affiliation(s)
- Rahul H Dave
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, Il 60612-7342, USA
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Peters MF, Scott CW. Evaluating Cellular Impedance Assays for Detection of GPCR Pleiotropic Signaling and Functional Selectivity. ACTA ACUST UNITED AC 2009; 14:246-55. [DOI: 10.1177/1087057108330115] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
G-protein—coupled receptors can couple to different signal transduction pathways in different cell types (termed cell-specific signaling) and can activate different signaling pathways depending on the receptor conformation(s) stabilized by the activating ligand (functional selectivity). These concepts offer potential for developing pathway-specific drugs that increase efficacy and reduce side effects. Despite significant interest, functional selectivity has been difficult to exploit in drug discovery, in part due to the burden of multiple assays. Cellular impedance assays use an emerging technology that can qualitatively distinguish Gs, Gi/o, and Gq signaling in a single assay and is thereby suited for studying these pharmacological concepts. Cellular impedance confirmed cell-specific Gs and Gq coupling for the melanocortin-4 receptor and dual Gi and Gs signaling with the cannabinoid-1 (CB1) receptor. The balance of Gi versus Gs signaling depended on the cell line. In CB1-HEKs, Giand Gs-like responses combined to yield a novel impedance profile demonstrating the dynamic nature of these traces. Cellspecific signaling was observed with endogenous D1 receptor in U-2 cells and SK-N-MC cells, yet the pharmacological profile of partial and full agonists was similar in both cell lines. We conclude that the dynamic impedance profile encodes valuable relative signaling information and is sufficiently robust to help evaluate cell-specific signaling and functional selectivity. ( Journal of Biomolecular Screening 2009:246-255)
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Affiliation(s)
- Matthew F. Peters
- Lead Generation Department, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware,
| | - Clay W. Scott
- Lead Generation Department, AstraZeneca Pharmaceuticals LP, Wilmington, Delaware
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Abstract
Signaling from G(i/o)-coupled G protein-coupled receptors (GPCRs), such as the serotonin 1B, cannabinoid 1, and dopamine D2 receptors, inhibits cAMP production by adenylyl cyclases and activates protein kinases, such as Src, mitogen-activated protein kinases 1 and 2, and Akt. Activation of these protein kinases results in stimulation of neurite outgrowth in the central nervous system (CNS) and in neuronal cell lines. This Connections Map traces downstream signaling pathways from G(i/o)-coupled GPCRs to key protein kinases and key transcription factors involved in neuronal differentiation. Components in the Science Signaling Connections Map are linked to Nature Molecule Pages. This interoperability provides ready access to detail that includes information about specific states for the nodes.
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Affiliation(s)
- Avi Ma'ayan
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029, USA.
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Tso PH, Morris CJ, Yung LY, Ip NY, Wong YH. Multiple Gi Proteins Participate in Nerve Growth Factor-Induced Activation of c-Jun N-terminal Kinases in PC12 Cells. Neurochem Res 2008; 34:1101-12. [DOI: 10.1007/s11064-008-9880-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2008] [Indexed: 01/21/2023]
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Roychowdhury S, Rasenick MM. Submembraneous microtubule cytoskeleton: regulation of microtubule assembly by heterotrimeric Gproteins. FEBS J 2008; 275:4654-63. [PMID: 18754776 PMCID: PMC2782913 DOI: 10.1111/j.1742-4658.2008.06614.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heterotrimeric Gproteins participate in signal transduction by transferring signals from cell surface receptors to intracellular effector molecules. Gproteins also interact with microtubules and participate in microtubule-dependent centrosome/chromosome movement during cell division, as well as neuronal differentiation. In recent years, significant progress has been made in our understanding of the biochemical/functional interactions between Gprotein subunits (alpha and betagamma) and microtubules, and the molecular details emerging from these studies suggest that alpha and betagamma subunits of Gproteins interact with tubulin/microtubules to regulate the assembly/dynamics of microtubules, providing a novel mechanism for hormone- or neurotransmitter-induced rapid remodeling of cytoskeleton, regulation of the mitotic spindle for centrosome/chromosome movements in cell division, and neuronal differentiation in which structural plasticity mediated by microtubules is important for appropriate synaptic connections and signal transmission.
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Affiliation(s)
- Sukla Roychowdhury
- Department of Biological Sciences, University of Texas, El Paso, TX, USA.
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Yung LY, Tso PH, Wu EH, Yu JC, Ip NY, Wong YH. Nerve growth factor-induced stimulation of p38 mitogen-activated protein kinase in PC12 cells is partially mediated via Gi/o proteins. Cell Signal 2008; 20:1538-44. [DOI: 10.1016/j.cellsig.2008.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 04/10/2008] [Accepted: 04/11/2008] [Indexed: 12/21/2022]
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The genomic determinants of alcohol preference in mice. Mamm Genome 2008; 19:352-65. [PMID: 18563486 DOI: 10.1007/s00335-008-9115-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 05/14/2008] [Indexed: 02/06/2023]
Abstract
Searches for the identity of genes that influence the levels of alcohol consumption by humans and other animals have often been driven by presupposition of the importance of particular gene products in determining positively or negatively reinforcing effects of ethanol. We have taken an unbiased approach and performed a meta-analysis across three types of mouse populations to correlate brain gene expression with levels of alcohol intake. Our studies, using filtering procedures based on QTL analysis, produced a list of eight candidate genes with highly heritable expression, which could explain a significant amount of the variance in alcohol preference in mice. Using the Allen Brain Atlas for gene expression, we noted that the candidate genes' expression was localized to the olfactory and limbic areas as well as to the orbitofrontal cortex. Informatics techniques and pathway analysis illustrated the role of the candidate genes in neuronal migration, differentiation, and synaptic remodeling. The importance of olfactory cues, learning and memory formation (Pavlovian conditioning), and cortical executive function, for regulating alcohol intake by animals (including humans), is discussed.
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Abstract
Heterotrimeric GTP-binding protein transduce signals initiated by a variety of hormones and neurotransmitters. Go, a member of the Go/Gi family, is the most abundant heterotrimeric GTP-binding protein in nervous tissues and has been implicated in neuronal differentiation. The mechanism by which Go modulates neuronal differentiation has not been, however, fully elucidated. Here, we identified small GTPase Rit as an interacting partner of the alpha-subunit of Go (Goalpha). The biochemical characterizations of Goalpha::Rit interaction revealed that Rit is a candidate downstream effector for Goalpha. Furthermore, dominant negative Rit inhibited Goalpha-induced neurite outgrowth and Erk phosphorylation in Neuro2a cells. These results suggest that Rit may be involved in the signaling pathway for Goalpha-mediated neuronal differentiation.
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CalDAG-GEFI and protein kinase C represent alternative pathways leading to activation of integrin alphaIIbbeta3 in platelets. Blood 2008; 112:1696-703. [PMID: 18544684 DOI: 10.1182/blood-2008-02-139733] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Second messenger-mediated inside-out activation of integrin alphaIIbbeta3 is a key step in platelet aggregation. We recently showed strongly impaired but not absent alphaIIbbeta3-mediated aggregation of CalDAG-GEFI-deficient platelets activated with various agonists. Here we further evaluated the roles of CalDAG-GEFI and protein kinase C (PKC) for alphaIIbbeta3 activation in platelets activated with a PAR4 receptor-specific agonist, GYPGKF (PAR4p). Compared with wild-type controls, platelets treated with the PKC inhibitor Ro31-8220 or CalDAG-GEFI-deficient platelets showed a marked defect in aggregation at low (< 1mM PAR4p) but not high PAR4p concentrations. Blocking of PKC function in CalDAG-GEFI-deficient platelets, how-ever, strongly decreased aggregation at all PAR4p concentrations, demonstrating that CalDAG-GEFI and PKC represent separate, but synergizing, pathways important for alphaIIbbeta3 activation. PAR4p-induced aggregation in the absence of CalDAG-GEFI required cosignaling through the Galphai-coupled receptor for ADP, P2Y12. Independent roles for CalDAG-GEFI and PKC/Galphai signaling were also observed for PAR4p-induced activation of the small GTPase Rap1, with CalDAG-GEFI mediating the rapid but reversible activation of this small GTPase. In summary, our study identifies CalDAG-GEFI and PKC as independent pathways leading to Rap1 and alphaIIbbeta3 activation in mouse platelets activated through the PAR4 receptor.
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Kim KW, Jo YH, Zhao L, Stallings NR, Chua SC, Parker KL. Steroidogenic factor 1 regulates expression of the cannabinoid receptor 1 in the ventromedial hypothalamic nucleus. Mol Endocrinol 2008; 22:1950-61. [PMID: 18511494 DOI: 10.1210/me.2008-0127] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The nuclear receptor steroidogenic factor 1 (SF-1) plays essential roles in the development and function of the ventromedial hypothalamic nucleus (VMH). Considerable evidence links the VMH and SF-1 with the regulation of energy homeostasis. Here, we demonstrate that SF-1 colocalizes in VMH neurons with the cannabinoid receptor 1 (CB1R) and that a specific CB1R agonist modulates electrical activity of SF-1 neurons in hypothalamic slice preparations. We further show that SF-1 directly regulates CB1R gene expression via a SF-1-responsive element at -101 in its 5'-flanking region. Finally, we show that knockout mice with selective inactivation of SF-1 in the brain have decreased expression of CB1R in the region of the VMH and exhibit a blunted response to systemically administered CB1R agonists. These studies suggest that SF-1 directly regulates the expression of CB1R, which has been implicated in the regulation of energy homeostasis and anxiety-like behavior.
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Affiliation(s)
- Ki Woo Kim
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas 75390-8857, USA
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Bromberg KD, Iyengar R, He JC. Regulation of neurite outgrowth by G(i/o) signaling pathways. FRONT BIOSCI-LANDMRK 2008; 13:4544-57. [PMID: 18508528 DOI: 10.2741/3022] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Neurogenesis is a long and winding journey. A neural progenitor cell migrates long distances, differentiates by forming a single axon and multiple dendrites, undergoes maturation, and ultimately survives. The initial formation of neurites during neuronal differentiation, commonly referred to as "neurite outgrowth," can be induced by a large repertoire of signals that stimulate an array of receptors and downstream signaling pathways. The G(i/o) family of heterotrimeric G-proteins are abundantly expressed in the brain and enriched at neuronal growth cones. Recent evidence has uncovered several G(i/o)-coupled receptors that induce neurite outgrowth and has begun to elucidate the underlying molecular mechanisms. Emerging data suggests that signals from several G(i/o)-coupled receptors converge at the transcription factor STAT3 to regulate neurite outgrowth and at Rac1 and Cdc42 to regulate cytoskeletal reorganization. Physiologically, signaling through G(i/o)-coupled cannabinoid receptors is critical for pro percentral nervous system development. As the mechanisms by which G(i/o)-coupled receptors regulate neurite outgrowth are clarified, it is becoming evident that modulating signals from G(i/o) and their receptors has great potential for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Kenneth D Bromberg
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, NY 10029, USA.
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