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Deng Z, Chen X, Zhang R, Kong L, Fang Y, Guo J, Shen B, Zhang L. Delta opioid peptide [D-ala2, D-leu5]-Enkephalin's ability to enhance mitophagy via TRPV4 to relieve ischemia/reperfusion injury in brain microvascular endothelial cells. Stroke Vasc Neurol 2024:svn-2023-003080. [PMID: 38697767 DOI: 10.1136/svn-2023-003080] [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: 01/03/2024] [Accepted: 04/20/2024] [Indexed: 05/05/2024] Open
Abstract
BACKGROUND Local brain tissue can suffer from ischaemia/reperfusion (I/R) injury, which lead to vascular endothelial damage. The peptide δ opioid receptor (δOR) agonist [D-ala2, D-leu5]-Enkephalin (DADLE) can reduce apoptosis caused by acute I/R injury in brain microvascular endothelial cells (BMECs). OBJECTIVE This study aims to explore the mechanism by which DADLE enhances the level of mitophagy in BMECs by upregulating the expression of transient receptor potential vanilloid subtype 4 (TRPV4). METHODS BMECs were extracted and made to undergo oxygen-glucose deprivation/reoxygenation (OGD/R) accompanied by DADLE. RNA-seq analysis revealed that DADLE induced increased TRPV4 expression. The CCK-8 method was used to assess the cellular viability; quantitative PCR (qPCR) was used to determine the mRNA expression of Drp1; western blot was used to determine the expression of TRPV4 and autophagy-related proteins; and calcium imaging was used to detect the calcium influx. Autophagosomes in in the cells' mitochondria were observed by using transmission electron microscopy. ELISA was used to measure ATP content, and a JC-1 fluorescent probe was used to detect mitochondrial membrane potential. RESULTS When compared with the OGD/R group, OGD/R+DADLE group showed significantly enhanced cellular viability; increased expression of TRPV4, Beclin-1, LC3-II/I, PINK1 and Parkin; decreased p62 expression; a marked rise in calcium influx; further increases in mitophagy, an increase in ATP synthesis and an elevation of mitochondrial membrane potential. These protective effects of DADLE can be blocked by a TRPV4 inhibitor HC067047 or RNAi of TRPV4. CONCLUSION DADLE can promote mitophagy in BMECs through TRPV4, improving mitochondrial function and relieving I/R injury.
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Affiliation(s)
- Zhongfang Deng
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Xiaoyu Chen
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Ran Zhang
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Lingchao Kong
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Yang Fang
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Jizheng Guo
- Department of Pathophysiology, Anhui Medical University, Hefei, Anhui, China
| | - Bing Shen
- Dr. Neher's Biophysics Laboratory for Innovative Drug Discovery, State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macao
| | - Lesha Zhang
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
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Perna E, Aguilera-Lizarraga J, Florens MV, Jain P, Theofanous SA, Hanning N, De Man JG, Berg M, De Winter B, Alpizar YA, Talavera K, Vanden Berghe P, Wouters M, Boeckxstaens G. Effect of resolvins on sensitisation of TRPV1 and visceral hypersensitivity in IBS. Gut 2021; 70:1275-1286. [PMID: 33023902 DOI: 10.1136/gutjnl-2020-321530] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Resolvins (RvD1, RvD2 and RvE1) are endogenous anti-inflammatory lipid mediators that display potent analgesic properties in somatic pain by modulating transient receptor potential vanilloid 1 (TRPV1) activation. To what extent these molecules could also have a beneficial effect on TRPV1 sensitisation and visceral hypersensitivity (VHS), mechanisms involved in IBS, remains unknown. DESIGN The effect of RvD1, RvD2 and RvE1 on TRPV1 activation and sensitisation by histamine or IBS supernatants was assessed on murine dorsal root ganglion (DRG) neurons using live Ca2+ imaging. Based on the results obtained in vitro, we further studied the effect of RvD2 in vivo using a murine model of post-infectious IBS and a rat model of post-inflammatory VHS. Finally, we also tested the effect of RvD2 on submucosal neurons in rectal biopsies of patients with IBS. RESULTS RvD1, RvD2 and RvE1 prevented histamine-induced TRPV1 sensitisation in DRG neurons at doses devoid of an analgesic effect. Of note, RvD2 also reversed TRPV1 sensitisation by histamine and IBS supernatant. This effect was blocked by the G protein receptor 18 (GPR18) antagonist O-1918 (3-30 µM) and by pertussis toxin. In addition, RvD2 reduced the capsaicin-induced Ca2+ response of rectal submucosal neurons of patients with IBS. Finally, treatment with RvD2 normalised pain responses to colorectal distention in both preclinical models of VHS. CONCLUSIONS Our data suggest that RvD2 and GPR18 agonists may represent interesting novel compounds to be further evaluated as treatment for IBS.
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Affiliation(s)
- Eluisa Perna
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Javier Aguilera-Lizarraga
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Morgane V Florens
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Piyush Jain
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Stavroula A Theofanous
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Nikita Hanning
- Laboratory of Experimental Medicine and Pediatrics (LEMP) and Infla-Med, research consortium of excellence, University of Antwerp, Antwerp, Belgium
| | - Joris G De Man
- Laboratory of Experimental Medicine and Pediatrics (LEMP) and Infla-Med, research consortium of excellence, University of Antwerp, Antwerp, Belgium
| | - Maya Berg
- Laboratory of Experimental Medicine and Pediatrics (LEMP) and Infla-Med, research consortium of excellence, University of Antwerp, Antwerp, Belgium
| | - Benedicte De Winter
- Laboratory of Experimental Medicine and Pediatrics (LEMP) and Infla-Med, research consortium of excellence, University of Antwerp, Antwerp, Belgium
| | | | - Karel Talavera
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric Neuroscience, Translational Research Center for Gastrointestinal (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Mira Wouters
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Guy Boeckxstaens
- Center of Intestinal Neuro-Immune Interaction, Translational Research Center for Gastrointestinal Disorders (TARGID), Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
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McMillan H, Lundy FT, Dunne OM, Al-Natour B, Jeanneau C, About I, Curtis TM, El Karim I. Endogenous Mas-related G-protein-coupled receptor X1 activates and sensitizes TRPA1 in a human model of peripheral nerves. FASEB J 2021; 35:e21492. [PMID: 33788969 DOI: 10.1096/fj.202001667rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/16/2021] [Accepted: 02/16/2021] [Indexed: 12/21/2022]
Abstract
Mas-related G-protein-coupled receptor X1 (MrgprX1) is a human-specific Mrgpr and its expression is restricted to primary sensory neurons. However, its role in nociception and pain signaling pathways is largely unknown. This study aims to investigate a role for MrgprX1 in nociception via interaction with the pain receptor, Transient Receptor Potential Ankyrin 1 (TRPA1), using in-vitro and in-vivo human neuronal models. MrgprX1 protein expression in human trigeminal nociceptors was investigated by the immunolabeling of the dental pulp and cultured peripheral neuronal equivalent (PNE) cells. MrgprX1 receptor signaling was monitored by Fura-2-based Ca2+ imaging using PNEs and membrane potential responses were measured using FluoVoltTM . Immunofluorescent staining revealed MrgprX1 expression in-vivo in dental afferents, which was more intense in inflamed compared to healthy dental pulps. Endogenous MrgprX1 protein expression was confirmed in the in-vitro human PNE model. MrgprX1 receptor signaling and the mechanisms through which it couples to TRPA1 were studied by Ca2+ imaging. Results showed that MrgprX1 activates TRPA1 and induces membrane depolarization in a TRPA1 dependent manner. In addition, MrgprX1 sensitizes TRPA1 to agonist stimulation via Protein Kinase C (PKC). The activation and sensitization of TRPA1 by MrgprX1 in a model of human nerves suggests an important role for this receptor in the modulation of nociception.
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Affiliation(s)
- Hayley McMillan
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
| | - Fionnuala T Lundy
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
| | - Orla M Dunne
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
| | - Banan Al-Natour
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
- Department of Oral Medicine and Oral Surgery, Faculty of Dentistry, Jordan University of Science and Technology, Irbid, Jordan
| | | | - Imad About
- Aix Marseille Univ, CNRS, ISM, Inst Movement Sci, Marseille, France
| | - Tim M Curtis
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
| | - Ikhlas El Karim
- School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, UK
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Jin YN, Cui ZH, Ma K, Yao JL, Ruan YY, Guo ZF. Characterization of ZmCOLD1, novel GPCR-Type G Protein genes involved in cold stress from Zea mays L. and the evolution analysis with those from other species. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:619-632. [PMID: 33854288 PMCID: PMC7981359 DOI: 10.1007/s12298-021-00966-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/27/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Maize is one of the most vital staple crops worldwide. G proteins modulate plentiful signaling pathways, and G protein-coupled receptor-type G proteins (GPCRs) are highly conserved membrane proteins in plants. However, researches on maize G proteins and GPCRs are scarce. In this study, we identified three novel GPCR-Type G Protein (GTG) genes from chromosome 10 (Chr 10) in maize, designated as ZmCOLD1-10A, ZmCOLD1-10B and ZmCOLD1-10C. Their amino acid sequences had high similarity to TaCOLD1 from wheat and OsCOLD1 from rice. They contained the basic characteristics of GTG/COLD1 proteins, including GPCR-like topology, the conserved hydrophilic loop (HL) domain, DUF3735 (domain of unknown function 3735) domain, GTPase-activating domain, and ATP/GTP-binding domain. Subcellular localization analyses of ZmCOLD1 proteins suggested that ZmCOLD1 proteins localized on plasma membrane (PM) and endoplasmic reticulum (ER). Furthermore, amino acid sequence alignment verified the conservation of the key 187th amino acid T in maize and other wild maize-relative species. Evolutionary relationship among plants GTG/COLD1 proteins family displayed strong group-specificity. Expression analysis indicated that ZmCOLD1-10A was cold-induced and inhibited by light. Together, these results suggested that ZmCOLD1 genes had potential value to improve cold tolerance and to contribute crops growth and molecular breeding.
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Affiliation(s)
- Ya-Nan Jin
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
- College of Life Science, Inner Mongolia University for the Nationalities, Tongliao, 028000 China
| | - Zhen-hai Cui
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Ke Ma
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Jia-Lu Yao
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Yan-Ye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Zhi-Fu Guo
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
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5
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The endocannabinoid system. Essays Biochem 2021; 64:485-499. [PMID: 32648908 DOI: 10.1042/ebc20190086] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/26/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022]
Abstract
Thirty years ago, the discovery of a cannabinoid (CB) receptor that interacts with the psychoactive compound in Cannabis led to the identification of anandamide, an endogenous receptor ligand or endocannabinoid. Research on endocannabinoids has since exploded, and additional receptors along with their lipid mediators and signaling pathways continue to be revealed. Specifically, in humans, the release of endocannabinoids from membrane lipids occurs on demand and the signaling process is rapidly attenuated by the breakdown of the ligand suggesting a tight regulation of the endocannabinoid system (ECS). Additionally, the varying distribution of CB receptors between the central nervous system and other tissues allows for the ECS to participate in a wide range of cognitive and physiological processes. Select plant-derived 'phyto'cannabinoids such as Δ-9-tetrahydrocannabinol (Δ9-THC) bind to the CB receptors and trigger the ECS, and in the case of Δ9-THC, while it has therapeutic value, can also produce detrimental effects. Current research is aimed at the identification of additional phytocannabinoids with minimal psychotropic effects with potential for therapeutic development. Although decades of research on the ECS and its components have expanded our understanding of the mechanisms and implications of endocannabinoid signaling in mammals, it continues to evolve. Here, we provide a brief overview of the ECS and its overlap with other related lipid-mediated signaling pathways.
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Tanaka K, Joshi D, Timalsina S, Schwartz MA. Early events in endothelial flow sensing. Cytoskeleton (Hoboken) 2021; 78:217-231. [PMID: 33543538 DOI: 10.1002/cm.21652] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 12/15/2022]
Abstract
Responses of vascular and lymphatic endothelial cells (ECs) to fluid shear stress (FSS) from blood or lymphatic fluid flow govern the development, physiology, and diseases of these structures. Extensive research has characterized the signaling, gene expression and cytoskeletal pathways that mediate effects on EC phenotype and vascular morphogenesis. But the primary mechanisms by which ECs transduce the weak forces from flow into biochemical signals are less well understood. This review covers recent advances in our understanding of the immediate mechanisms of FSS mechanotransduction, integrating results from different disciplines, addressing their roles in development, physiology and disease, and suggesting important questions for future work.
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Affiliation(s)
- Keiichiro Tanaka
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Divyesh Joshi
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Sushma Timalsina
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Martin A Schwartz
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut, USA.,Department of Cell Biology, Yale University, New Haven, Connecticut, USA.,Department of Biomedical engineering, Yale University, New Haven, Connecticut, USA
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7
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Oronowicz J, Reinhard J, Reinach PS, Ludwiczak S, Luo H, Omar Ba Salem MH, Kraemer MM, Biebermann H, Kakkassery V, Mergler S. Ascorbate-induced oxidative stress mediates TRP channel activation and cytotoxicity in human etoposide-sensitive and -resistant retinoblastoma cells. J Transl Med 2021; 101:70-88. [PMID: 32948812 PMCID: PMC7758186 DOI: 10.1038/s41374-020-00485-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/29/2020] [Accepted: 08/11/2020] [Indexed: 02/08/2023] Open
Abstract
There are indications that pharmacological doses of ascorbate (Asc) used as an adjuvant improve the chemotherapeutic management of cancer. This favorable outcome stems from its cytotoxic effects due to prooxidative mechanisms. Since regulation of intracellular Ca2+ levels contributes to the maintenance of cell viability, we hypothesized that one of the effects of Asc includes disrupting regulation of intracellular Ca2+ homeostasis. Accordingly, we determined if Asc induced intracellular Ca2+ influx through activation of pertussis sensitive Gi/o-coupled GPCR which in turn activated transient receptor potential (TRP) channels in both etoposide-resistant and -sensitive retinoblastoma (WERI-Rb1) tumor cells. Ca2+ imaging, whole-cell patch-clamping, and quantitative real-time PCR (qRT-PCR) were performed in parallel with measurements of RB cell survival using Trypan Blue cell dye exclusion. TRPM7 gene expression levels were similar in both cell lines whereas TRPV1, TRPM2, TRPA1, TRPC5, TRPV4, and TRPM8 gene expression levels were downregulated in the etoposide-resistant WERI-Rb1 cells. In the presence of extracellular Ca2+, 1 mM Asc induced larger intracellular Ca2+ transients in the etoposide-resistant WERI-Rb1 than in their etoposide-sensitive counterpart. With either 100 µM CPZ, 500 µM La3+, 10 mM NAC, or 100 µM 2-APB, these Ca2+ transients were markedly diminished. These inhibitors also had corresponding inhibitory effects on Asc-induced rises in whole-cell currents. Pertussis toxin (PTX) preincubation blocked rises in Ca2+ influx. Microscopic analyses showed that after 4 days of exposure to 1 mM Asc cell viability fell by nearly 100% in both RB cell lines. Taken together, one of the effects underlying oxidative mediated Asc-induced WERI-Rb1 cytotoxicity stems from its promotion of Gi/o coupled GPCR mediated increases in intracellular Ca2+ influx through TRP channels. Therefore, designing drugs targeting TRP channel modulation may be a viable approach to increase the efficacy of chemotherapeutic treatment of RB. Furthermore, Asc may be indicated as a possible supportive agent in anti-cancer therapies.
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Affiliation(s)
- Jakub Oronowicz
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Jacqueline Reinhard
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Peter Sol Reinach
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, PR China
| | - Szymon Ludwiczak
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Huan Luo
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Marah Hussain Omar Ba Salem
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Miriam Monika Kraemer
- Department of Cell Morphology and Molecular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Heike Biebermann
- Institut für Experimentelle Pädiatrische Endokrinologie, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
| | - Vinodh Kakkassery
- Universität zu Lübeck, Klinik für Augenheilkunde - Universitätsklinikum Schleswig-Holstein (Campus Lübeck), Lübeck, Germany.
| | - Stefan Mergler
- Klinik für Augenheilkunde, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany.
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8
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Zhao XF. G protein-coupled receptors function as cell membrane receptors for the steroid hormone 20-hydroxyecdysone. Cell Commun Signal 2020; 18:146. [PMID: 32907599 PMCID: PMC7488307 DOI: 10.1186/s12964-020-00620-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 06/27/2020] [Indexed: 12/16/2022] Open
Abstract
Abstract G protein-coupled receptors (GPCRs) are cell membrane receptors for various ligands. Recent studies have suggested that GPCRs transmit animal steroid hormone signals. Certain GPCRs have been shown to bind steroid hormones, for example, G protein-coupled estrogen receptor 1 (GPER1) binds estrogen in humans, and Drosophila dopamine/ecdysteroid receptor (DopEcR) binds the molting hormone 20-hydroxyecdysone (20E) in insects. This review summarizes the research progress on GPCRs as animal steroid hormone cell membrane receptors, including the nuclear and cell membrane receptors of steroid hormones in mammals and insects, the 20E signaling cascade via GPCRs, termination of 20E signaling, and the relationship between genomic action and the nongenomic action of 20E. Studies indicate that 20E induces a signal via GPCRs to regulate rapid cellular responses, including rapid Ca2+ release from the endoplasmic reticulum and influx from the extracellular medium, as well as rapid protein phosphorylation and subcellular translocation. 20E via the GPCR/Ca2+/PKC/signaling axis and the GPCR/cAMP/PKA-signaling axis regulates gene transcription by adjusting transcription complex formation and DNA binding activity. GPCRs can bind 20E in the cell membrane and after being isolated, suggesting GPCRs as cell membrane receptors of 20E. This review deepens our understanding of GPCRs as steroid hormone cell membrane receptors and the GPCR-mediated signaling pathway of 20E (20E-GPCR pathway), which will promote further study of steroid hormone signaling via GPCRs, and presents GPCRs as targets to explore new pharmaceutical materials to treat steroid hormone-related diseases or control pest insects. Video abstract
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Affiliation(s)
- Xiao-Fan Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, 266237, China.
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Starkus J, Jansen C, Shimoda LMN, Stokes AJ, Small-Howard AL, Turner H. Diverse TRPV1 responses to cannabinoids. Channels (Austin) 2019; 13:172-191. [PMID: 31096838 PMCID: PMC6557596 DOI: 10.1080/19336950.2019.1619436] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 05/05/2019] [Accepted: 05/09/2019] [Indexed: 02/06/2023] Open
Abstract
Cannabinoid compounds are potential analgesics. Users of medicinal Cannabis report efficacy for pain control, clinical studies show that cannabis can be effective and opioid sparing in chronic pain, and some constituent cannabinoids have been shown to target nociceptive ion channels. Here, we explore and compare a suite of cannabinoids for their impact upon the physiology of TRPV1. The cannabinoids tested evoke differential responses in terms of kinetics of activation and inactivation. Cannabinoid activation of TRPV1 displays significant dependence on internal and external calcium levels. Cannabinoid activation of TRPV1 does not appear to induce the highly permeant, pore-dilated channel state seen with Capsaicin, even at high current amplitudes. Finally, we analyzed cannabinoid responses at nociceptive channels other than TRPV1 (TRPV2, TRPM8, and TRPA1), and report that cannabinoids differentially activate these channels. On the basis of response activation and kinetics, state-selectivity and receptor selectivity, it may be possible to rationally design approaches to pain using single or multiple cannabinoids.
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Affiliation(s)
- J. Starkus
- Laboratory of Immunology and Signal Transduction, Chaminade University, Honolulu, HI, USA
| | - C. Jansen
- Laboratory of Immunology and Signal Transduction, Chaminade University, Honolulu, HI, USA
| | - L. M. N. Shimoda
- Laboratory of Immunology and Signal Transduction, Chaminade University, Honolulu, HI, USA
| | - A. J. Stokes
- Laboratory of Experimental Medicine, John A. Burns School of Medicine, Honolulu, HI, USA
| | | | - H. Turner
- Laboratory of Immunology and Signal Transduction, Chaminade University, Honolulu, HI, USA
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Muller C, Morales P, Reggio PH. Cannabinoid Ligands Targeting TRP Channels. Front Mol Neurosci 2019; 11:487. [PMID: 30697147 PMCID: PMC6340993 DOI: 10.3389/fnmol.2018.00487] [Citation(s) in RCA: 327] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/14/2018] [Indexed: 12/14/2022] Open
Abstract
Transient receptor potential (TRP) channels are a group of membrane proteins involved in the transduction of a plethora of chemical and physical stimuli. These channels modulate ion entry, mediating a variety of neural signaling processes implicated in the sensation of temperature, pressure, and pH, as well as smell, taste, vision, and pain perception. Many diseases involve TRP channel dysfunction, including neuropathic pain, inflammation, and respiratory disorders. In the pursuit of new treatments for these disorders, it was discovered that cannabinoids can modulate a certain subset of TRP channels. The TRP vanilloid (TRPV), TRP ankyrin (TRPA), and TRP melastatin (TRPM) subfamilies were all found to contain channels that can be modulated by several endogenous, phytogenic, and synthetic cannabinoids. To date, six TRP channels from the three subfamilies mentioned above have been reported to mediate cannabinoid activity: TRPV1, TRPV2, TRPV3, TRPV4, TRPA1, and TRPM8. The increasing data regarding cannabinoid interactions with these receptors has prompted some researchers to consider these TRP channels to be “ionotropic cannabinoid receptors.” Although CB1 and CB2 are considered to be the canonical cannabinoid receptors, there is significant overlap between cannabinoids and ligands of TRP receptors. The first endogenous agonist of TRPV1 to be discovered was the endocannabinoid, anandamide (AEA). Similarly, N-arachidonyl dopamine (NADA) and AEA were the first endogenous TRPM8 antagonists discovered. Additionally, Δ9-tetrahydrocannabinol (Δ9-THC), the most abundant psychotropic compound in cannabis, acts most potently at TRPV2, moderately modulates TRPV3, TRPV4, TRPA1, and TRPM8, though Δ9-THC is not reported to modulate TRPV1. Moreover, TRP receptors may modulate effects of synthetic cannabinoids used in research. One common research tool is WIN55,212-2, a CB1 agonist that also exerts analgesic effects by desensitizing TRPA1 and TRPV1. In this review article, we aim to provide an overview and classification of the cannabinoid ligands that have been reported to modulate TRP channels and their therapeutic potential.
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Affiliation(s)
- Chanté Muller
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Paula Morales
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
| | - Patricia H Reggio
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, United States
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Bräunig J, Mergler S, Jyrch S, Hoefig CS, Rosowski M, Mittag J, Biebermann H, Khajavi N. 3-Iodothyronamine Activates a Set of Membrane Proteins in Murine Hypothalamic Cell Lines. Front Endocrinol (Lausanne) 2018; 9:523. [PMID: 30298050 PMCID: PMC6161562 DOI: 10.3389/fendo.2018.00523] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/21/2018] [Indexed: 01/26/2023] Open
Abstract
3-Iodothyronamine (3-T1AM) is an endogenous thyroid hormone metabolite. The profound pharmacological effects of 3-T1AM on energy metabolism and thermal homeostasis have raised interest to elucidate its signaling properties in tissues that pertain to metabolic regulation and thermogenesis. Previous studies identified G protein-coupled receptors (GPCRs) and transient receptor potential channels (TRPs) as targets of 3-T1AM in different cell types. These two superfamilies of membrane proteins are largely expressed in tissue which influences energy balance and metabolism. As the first indication that 3-T1AM virtually modulates the function of the neurons in hypothalamus, we observed that intraperitoneal administration of 50 mg/kg bodyweight of 3-T1AM significantly increased the c-FOS activation in the paraventricular nucleus (PVN) of C57BL/6 mice. To elucidate the underlying mechanism behind this 3-T1AM-induced signalosome, we used three different murine hypothalamic cell lines, which are all known to express PVN markers, GT1-7, mHypoE-N39 (N39) and mHypoE-N41 (N41). Various aminergic GPCRs, which are the known targets of 3-T1AM, as well as numerous members of TRP channel superfamily, are expressed in these cell lines. Effects of 3-T1AM on activation of GPCRs were tested for the two major signaling pathways, the action of Gαs/adenylyl cyclase and Gi/o. Here, we demonstrated that this thyroid hormone metabolite has no significant effect on Gi/o signaling and only a minor effect on the Gαs/adenylyl cyclase pathway, despite the expression of known GPCR targets of 3-T1AM. Next, to test for other potential mechanisms involved in 3-T1AM-induced c-FOS activation in PVN, we evaluated the effect of 3-T1AM on the intracellular Ca2+ concentration and whole-cell currents. The fluorescence-optic measurements showed a significant increase of intracellular Ca2+ concentration in the three cell lines in the presence of 10 μM 3-T1AM. Furthermore, this thyroid hormone metabolite led to an increase of whole-cell currents in N41 cells. Interestingly, the TRPM8 selective inhibitor (10 μM AMTB) reduced the 3-T1AM stimulatory effects on cytosolic Ca2+ and whole-cell currents. Our results suggest that the profound pharmacological effects of 3-T1AM on selected brain nuclei of murine hypothalamus, which are known to be involved in energy metabolism and thermoregulation, might be partially attributable to TRP channel activation in hypothalamic cells.
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Affiliation(s)
- Julia Bräunig
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Stefan Mergler
- Klinik für Augenheilkunde, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sabine Jyrch
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Carolin S. Hoefig
- Institute of Experimental Endocrinology, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Department of Cell & Molecular Biology, Karolinska Instituet, Stockholm, Sweden
| | - Mark Rosowski
- Department Medical Biotechnology, Institute of Biotechnology, Technical University of Berlin, Berlin, Germany
| | - Jens Mittag
- Department of Cell & Molecular Biology, Karolinska Instituet, Stockholm, Sweden
- University of Lübeck – Center of Brain Behavior and Metabolism, Lübeck, Germany
| | - Heike Biebermann
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Noushafarin Khajavi
- Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Berlin, Germany
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Knezevic NN, Yekkirala A, Yaksh TL. Basic/Translational Development of Forthcoming Opioid- and Nonopioid-Targeted Pain Therapeutics. Anesth Analg 2017; 125:1714-1732. [PMID: 29049116 PMCID: PMC5679134 DOI: 10.1213/ane.0000000000002442] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Opioids represent an efficacious therapeutic modality for some, but not all pain states. Singular reliance on opioid therapy for pain management has limitations, and abuse potential has deleterious consequences for patient and society. Our understanding of pain biology has yielded insights and opportunities for alternatives to conventional opioid agonists. The aim is to have efficacious therapies, with acceptable side effect profiles and minimal abuse potential, which is to say an absence of reinforcing activity in the absence of a pain state. The present work provides a nonexclusive overview of current drug targets and potential future directions of research and development. We discuss channel activators and blockers, including sodium channel blockers, potassium channel activators, and calcium channel blockers; glutamate receptor-targeted agents, including N-methyl-D-aspartate, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid, and metabotropic receptors. Furthermore, we discuss therapeutics targeted at γ-aminobutyric acid, α2-adrenergic, and opioid receptors. We also considered antagonists of angiotensin 2 and Toll receptors and agonists/antagonists of adenosine, purine receptors, and cannabinoids. Novel targets considered are those focusing on lipid mediators and anti-inflammatory cytokines. Of interest is development of novel targeting strategies, which produce long-term alterations in pain signaling, including viral transfection and toxins. We consider issues in the development of druggable molecules, including preclinical screening. While there are examples of successful translation, mechanistically promising preclinical candidates may unexpectedly fail during clinical trials because the preclinical models may not recapitulate the particular human pain condition being addressed. Molecular target characterization can diminish the disconnect between preclinical and humans' targets, which should assist in developing nonaddictive analgesics.
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Affiliation(s)
- Nebojsa Nick Knezevic
- From the *Department of Anesthesiology, Advocate Illinois Masonic Medical Center Chicago, Illinois; Departments of †Anesthesiology and ‡Surgery, University of Illinois, Chicago, Illinois; §Department of Neurobiology, Harvard Medical School, and Boston Children's Hospital, Boston, Massachusetts; ‖Blue Therapeutics, Harvard Innovation Launch Lab, Allston, Massachusetts; and Departments of ¶Anesthesiology and #Pharmacology, University of California, San Diego, La Jolla, California
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Abstract
Acute and chronic pain complaints, although common, are generally poorly served by existing therapies. This unmet clinical need reflects a failure to develop novel classes of analgesics with superior efficacy, diminished adverse effects and a lower abuse liability than those currently available. Reasons for this include the heterogeneity of clinical pain conditions, the complexity and diversity of underlying pathophysiological mechanisms, and the unreliability of some preclinical pain models. However, recent advances in our understanding of the neurobiology of pain are beginning to offer opportunities for developing novel therapeutic strategies and revisiting existing targets, including modulating ion channels, enzymes and G-protein-coupled receptors.
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14
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Kleinau G, Müller A, Biebermann H. Oligomerization of GPCRs involved in endocrine regulation. J Mol Endocrinol 2016; 57:R59-80. [PMID: 27151573 DOI: 10.1530/jme-16-0049] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 05/04/2016] [Indexed: 12/27/2022]
Abstract
More than 800 different human membrane-spanning G-protein-coupled receptors (GPCRs) serve as signal transducers at biological barriers. These receptors are activated by a wide variety of ligands such as peptides, ions and hormones, and are able to activate a diverse set of intracellular signaling pathways. GPCRs are of central importance in endocrine regulation, which underpins the significance of comprehensively studying these receptors and interrelated systems. During the last decade, the capacity for multimerization of GPCRs was found to be a common and functionally relevant property. The interaction between GPCR monomers results in higher order complexes such as homomers (identical receptor subtype) or heteromers (different receptor subtypes), which may be present in a specific and dynamic monomer/oligomer equilibrium. It is widely accepted that the oligomerization of GPCRs is a mechanism for determining the fine-tuning and expansion of cellular processes by modification of ligand action, expression levels, and related signaling outcome. Accordingly, oligomerization provides exciting opportunities to optimize pharmacological treatment with respect to receptor target and tissue selectivity or for the development of diagnostic tools. On the other hand, GPCR heteromerization may be a potential reason for the undesired side effects of pharmacological interventions, faced with numerous and common mutual signaling modifications in heteromeric constellations. Finally, detailed deciphering of the physiological occurrence and relevance of specific GPCR/GPCR-ligand interactions poses a future challenge. This review will tackle the aspects of GPCR oligomerization with specific emphasis on family A GPCRs involved in endocrine regulation, whereby only a subset of these receptors will be discussed in detail.
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Affiliation(s)
- Gunnar Kleinau
- Institute of Experimental Pediatric Endocrinology (IEPE)Charité-Universitätsmedizin, Berlin, Germany
| | - Anne Müller
- Institute of Experimental Pediatric Endocrinology (IEPE)Charité-Universitätsmedizin, Berlin, Germany
| | - Heike Biebermann
- Institute of Experimental Pediatric Endocrinology (IEPE)Charité-Universitätsmedizin, Berlin, Germany
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15
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Kurozumi A, Goto Y, Okato A, Ichikawa T, Seki N. Aberrantly expressed microRNAs in bladder cancer and renal cell carcinoma. J Hum Genet 2016; 62:49-56. [PMID: 27357429 DOI: 10.1038/jhg.2016.84] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/25/2016] [Accepted: 05/26/2016] [Indexed: 02/06/2023]
Abstract
Bladder cancer (BC) and renal cell carcinoma (RCC) are frequently diagnosed urinary tract cancers. Recently developed molecular-targeted therapies for RCC have shown remarkable therapeutic efficacy; however, no targeted therapeutics are currently approved for the treatment of BC, and few effective treatment options exist. Current studies have shown that small noncoding RNA molecules have major roles in cancer cells. MicroRNAs (miRNAs) are endogenous small noncoding RNA molecules that regulate protein-/nonprotein-coding RNAs in human cells. A large body of evidence suggests that aberrantly expressed miRNAs are deeply involved in the pathogenesis of human cancers. In this paper, we review recently published miRNA expression signatures of BC and RCC. We focus on downregulated or upregulated miRNAs in multiple signatures and discuss putative target genes of miRNAs. Comparisons of RCC and BC expression signatures revealed that the two types of cancer showed opposite expression patterns for miR-200 family miRNAs (i.e., miR-141/200c and miR-200a/200b/429). We discuss in silico analysis of genes targeted by miR-200 family miRNAs and the molecular mechanisms underlying BC and RCC.
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Affiliation(s)
- Akira Kurozumi
- Department of Functional Genomics, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yusuke Goto
- Department of Functional Genomics, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Atsushi Okato
- Department of Functional Genomics, Graduate School of Medicine, Chiba University, Chiba, Japan.,Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tomohiko Ichikawa
- Department of Urology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Naohiko Seki
- Department of Functional Genomics, Graduate School of Medicine, Chiba University, Chiba, Japan
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Cai MJ, Dong DJ, Wang Y, Liu PC, Liu W, Wang JX, Zhao XF. G-protein-coupled receptor participates in 20-hydroxyecdysone signaling on the plasma membrane. Cell Commun Signal 2014; 12:9. [PMID: 24507557 PMCID: PMC3937218 DOI: 10.1186/1478-811x-12-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/03/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Animal steroid hormones are conventionally known to initiate signaling via a genomic pathway by binding to the nuclear receptors. The mechanism by which 20E initiates signaling via a nongenomic pathway is unclear. RESULTS We illustrate that 20E triggered the nongenomic pathway through a plasma membrane G-protein-coupled receptor (named ErGPCR) in the lepidopteran insect Helicoverpa armigera. The transcript of ErGPCR was increased at the larval molting stage and metamorphic molting stage by 20E regulation. Knockdown of ErGPCR via RNA interference in vivo blocked larval-pupal transition and suppressed 20E-induced gene expression. ErGPCR overexpression in the H. armigera epidermal cell line increased the 20E-induced gene expression. Through ErGPCR, 20E modulated Calponin nuclear translocation and phosphorylation, and induced a rapid increase in cytosolic Ca2+ levels. The inhibitors of T-type voltage-gated calcium channels and canonical transient receptor potential calcium channels repressed the 20E-induced Ca2+ increase. Truncation of the N-terminal extracellular region of ErGPCR inhibited its localization on the plasma membrane and 20E-induced gene expression. ErGPCR was not detected to bind with the steroid hormone analog [3H]Pon A. CONCLUSION These results suggest that ErGPCR participates in 20E signaling on the plasma membrane.
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Affiliation(s)
- Mei-Juan Cai
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Du-Juan Dong
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Yu Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Peng-Cheng Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Wen Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Jin-Xing Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
| | - Xiao-Fan Zhao
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan 250100, Shandong, China
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Palczewski K, Orban T. From atomic structures to neuronal functions of g protein-coupled receptors. Annu Rev Neurosci 2013; 36:139-64. [PMID: 23682660 DOI: 10.1146/annurev-neuro-062012-170313] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
G protein-coupled receptors (GPCRs) are essential mediators of signal transduction, neurotransmission, ion channel regulation, and other cellular events. GPCRs are activated by diverse stimuli, including light, enzymatic processing of their N-termini, and binding of proteins, peptides, or small molecules such as neurotransmitters. GPCR dysfunction caused by receptor mutations and environmental challenges contributes to many neurological diseases. Moreover, modern genetic technology has helped identify a rich array of mono- and multigenic defects in humans and animal models that connect such receptor dysfunction with disease affecting neuronal function. The visual system is especially suited to investigate GPCR structure and function because advanced imaging techniques permit structural studies of photoreceptor neurons at both macro and molecular levels that, together with biochemical and physiological assessment in animal models, provide a more complete understanding of GPCR signaling.
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Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4965, USA.
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