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Shaw VS, Mohammadi M, Quinn JA, Vashisth H, Neubig RR. An Interhelical Salt Bridge Controls Flexibility and Inhibitor Potency for Regulators of G-protein Signaling Proteins 4, 8, and 19. Mol Pharmacol 2019; 96:683-691. [PMID: 31543506 DOI: 10.1124/mol.119.117176] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/14/2019] [Indexed: 12/13/2022] Open
Abstract
Regulators of G-protein signaling (RGS) proteins modulate receptor signaling by binding to activated G-protein α-subunits, accelerating GTP hydrolysis. Selective inhibition of RGS proteins increases G-protein activity and may provide unique tissue specificity. Thiadiazolidinones (TDZDs) are covalent inhibitors that act on cysteine residues to inhibit RGS4, RGS8, and RGS19. There is a correlation between protein flexibility and potency of inhibition by the TDZD 4-[(4- fluorophenyl)methyl]-2-(4-methylphenyl)-1,2,4-thiadiazolidine-3,5-dione (CCG-50014). In the context of a single conserved cysteine residue on the α 4 helix, RGS19 is the most flexible and most potently inhibited by CCG-50014, followed by RGS4 and RGS8. In this work, we identify residues responsible for differences in both flexibility and potency of inhibition among RGS isoforms. RGS19 lacks a charged residue on the α 4 helix that is present in RGS4 and RGS8. Introducing a negative charge at this position (L118D) increased the thermal stability of RGS19 and decreased the potency of inhibition of CCG-50014 by 8-fold. Mutations eliminating salt bridge formation in RGS8 and RGS4 decreased thermal stability in RGS8 and increased potency of inhibition of both RGS4 and RGS8 by 4- and 2-fold, respectively. Molecular dynamics simulations with an added salt bridge in RGS19 (L118D) showed reduced RGS19 flexibility. Hydrogen-deuterium exchange studies showed striking differences in flexibility in the α 4 helix of RGS4, 8, and 19 with salt bridge-modifying mutations. These results show that the α 4 salt bridge-forming residue controls flexibility in several RGS isoforms and supports a causal relationship between RGS flexibility and the potency of TDZD inhibitors. SIGNIFICANCE STATEMENT: Inhibitor potency is often viewed in relation to the static structure of a target protein binding pocket. Using both experimental and computation studies we assess determinants of dynamics and inhibitor potency for three different RGS proteins. A single salt bridge-forming residue determines differences in flexibility between RGS isoforms; mutations either increase or decrease protein motion with correlated alterations in inhibitor potency. This strongly suggests a causal relationship between RGS protein flexibility and covalent inhibitor potency.
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Affiliation(s)
- Vincent S Shaw
- Department of Pharmacology and Toxicology (V.S.S., J.A.Q., R.R.N.) and Nicholas V. Perricone, M.D., Division of Dermatology, Department of Medicine (R.R.N.), Michigan State University, East Lansing, Michigan; and Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire (M.M., H.V.)
| | - Mohammadjavad Mohammadi
- Department of Pharmacology and Toxicology (V.S.S., J.A.Q., R.R.N.) and Nicholas V. Perricone, M.D., Division of Dermatology, Department of Medicine (R.R.N.), Michigan State University, East Lansing, Michigan; and Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire (M.M., H.V.)
| | - Josiah A Quinn
- Department of Pharmacology and Toxicology (V.S.S., J.A.Q., R.R.N.) and Nicholas V. Perricone, M.D., Division of Dermatology, Department of Medicine (R.R.N.), Michigan State University, East Lansing, Michigan; and Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire (M.M., H.V.)
| | - Harish Vashisth
- Department of Pharmacology and Toxicology (V.S.S., J.A.Q., R.R.N.) and Nicholas V. Perricone, M.D., Division of Dermatology, Department of Medicine (R.R.N.), Michigan State University, East Lansing, Michigan; and Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire (M.M., H.V.)
| | - Richard R Neubig
- Department of Pharmacology and Toxicology (V.S.S., J.A.Q., R.R.N.) and Nicholas V. Perricone, M.D., Division of Dermatology, Department of Medicine (R.R.N.), Michigan State University, East Lansing, Michigan; and Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire (M.M., H.V.)
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2
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Xu YH, Zhu Y, Zhu YY, Wei H, Zhang NN, Qin JS, Zhu XL, Yu M, Li YF. Abnormalities in FGF family members and their roles in modulating depression-related molecules. Eur J Neurosci 2019; 53:140-150. [PMID: 31491043 DOI: 10.1111/ejn.14570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/22/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022]
Abstract
The role of the fibroblast growth factor (FGF) system in depression has received considerable attention in recent years. To understand the role of this system, it is important to identify the specific members of the FGF family that have been implicated and the various mechanisms that they modulated. Here, we review the role of FGFs in depression and integrate evidence from clinical and basic research. These data suggest that changes in the FGF family are involved in depression and possibly in a wider range of psychiatric disorders. We analyse the abnormalities of FGF family members in depression and their roles in modulating depression-related molecules. The role of the FGF family in depression and related disorders needs to be studied in more detail.
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Affiliation(s)
- Yu-Hao Xu
- Department of Neurology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yan Zhu
- Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Radiology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yuan-Yuan Zhu
- Department of Neurology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Hong Wei
- Department of Neurology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Ning-Ning Zhang
- Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Radiology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Jia-Sheng Qin
- Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Radiology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Xiao-Lan Zhu
- Department of Central Laboratory, The Fourth Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Ming Yu
- Department of Neurology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yue-Feng Li
- Department of Neuroimaging laboratory, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China.,Department of Radiology, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
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3
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Albert PR, Vahid-Ansari F. The 5-HT1A receptor: Signaling to behavior. Biochimie 2019; 161:34-45. [DOI: 10.1016/j.biochi.2018.10.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/23/2018] [Indexed: 02/06/2023]
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4
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Senese NB, Rasenick MM, Traynor JR. The Role of G-proteins and G-protein Regulating Proteins in Depressive Disorders. Front Pharmacol 2018; 9:1289. [PMID: 30483131 PMCID: PMC6244039 DOI: 10.3389/fphar.2018.01289] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/22/2018] [Indexed: 11/29/2022] Open
Abstract
Progress toward new antidepressant therapies has been relatively slow over the past few decades, with the result that individuals suffering from depression often struggle to find an effective treatment – a process often requiring months. Furthermore, the neural factors that contribute to depression remain poorly understood, and there are many open questions regarding the mechanism of action of existing antidepressants. A better understanding of the molecular processes that underlie depression and contribute to antidepressant efficacy is therefore badly needed. In this review we highlight research investigating the role of G-proteins and the regulators of G-protein signaling (RGS) proteins, two protein families that are intimately involved in both the genesis of depressive states and the action of antidepressant drugs. Many antidepressants are known to indirectly affect the function of these proteins. Conversely, dysfunction of the G-protein and RGS systems can affect antidepressant efficacy. However, a great deal remains unknown about how these proteins interact with antidepressants. Findings pertinent to each individual G-protein and RGS protein are summarized from in vitro, in vivo, and clinical studies.
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Affiliation(s)
- Nicolas B Senese
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States.,Jesse Brown VA Medical Center, Chicago, IL, United States.,Department of Pharmacology and Edward F. Domino Research Center, University of Michigan, Ann Arbor, MI, United States
| | - Mark M Rasenick
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States.,Jesse Brown VA Medical Center, Chicago, IL, United States.,Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States
| | - John R Traynor
- Department of Pharmacology and Edward F. Domino Research Center, University of Michigan, Ann Arbor, MI, United States
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5
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Role of hippocampal 5-HT1A receptors in the antidepressant-like phenotype of mice expressing RGS-insensitive Gαi2 protein. Neuropharmacology 2018; 141:296-304. [PMID: 30189184 DOI: 10.1016/j.neuropharm.2018.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/31/2018] [Accepted: 09/02/2018] [Indexed: 12/11/2022]
Abstract
A single base mutation in the Gαi2 protein (G184S) renders this Gα subunit insensitive to the negative modulatory effects of Regulator of G-protein Signaling (RGS) proteins. Mice expressing this RGS insensitive (RGSi) variant of Gαi2 (RGSi Gαi2) display a spontaneous antidepressant-like phenotype that is reversible by treatment with the 5-HT1A receptor (5-HT1AR) antagonist WAY100635. Here we test the hypothesis that increased activity of 5-HT1ARs in the hippocampus of RGSi Gαi2 knock-in mice is responsible for the expression of the observed antidepressant-like behavior. We administered the 5-HT1AR antagonist WAY100635 or the agonist 8-OH-DPAT via bilateral intra-hippocampal infusion cannulae and evaluated antidepressant-like behavior using the tail suspension test (TST). WAY100635 reversed the antidepressant-like phenotype of the RGSi Gαi2 knock-in mice and 8-OH-DPAT produced an antidepressant-like response in wild type mice that was blocked by systemic WAY100635. Furthermore, intra-hippocampal infusion of the RGS19/4 inhibitor CCG-203769 produced an antidepressant-like effect in female mice. Ex-vivo slice recording confirmed the 5-HT1AR-mediated decrease in hippocampal CA1 pyramidal neuron excitability was enhanced in the RGSi Gαi2 knock-in mice. There was no change in hippocampal 5-HT1AR expression as measured by ligand binding but there was a compensatory reduction in Gαi proteins. The findings demonstrate that RGS protein control of hippocampal 5-HT1AR signaling is necessary and sufficient to account for the antidepressant-like phenotype in the RGSi Gαi2 knock-in mice and that RGS proteins highly expressed in the hippocampus should be investigated as targets for novel antidepressant therapies.
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6
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Wu H, Zhao Y, Huang Q, Cai M, Pan Q, Fu M, An X, Xia Z, Liu M, Jin Y, He L, Shang J. NK1R/5-HT1AR interaction is related to the regulation of melanogenesis. FASEB J 2018; 32:3193-3214. [PMID: 29430989 DOI: 10.1096/fj.201700564rr] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Substance P (SP) is a candidate mediator along the brain-skin axis and can mimic the effects of stress to regulate melanogenesis. Previously, we and others have found that the regulation of SP for pigmentary function was mediated by neurokinin 1 receptor (NK1R). Emerging evidence has accumulated that psychologic stress can induce dysfunction in the cutaneous serotonin 5-hydroxytryptamine (5-HT)-5-HT1A/1B receptor system, thereby resulting in skin hypopigmentation. Moreover, NK1R and 5-HTR (except 5-HT3) belong to GPCR. The present study aimed at assessing the possible existence of NK1R-5-HTR interactions and related melanogenic functions. Western blot and PCR detection revealed that SP reduced expression of 5-HT1A receptor via the NK1 receptor. Biochemical analyses showed that NK1R and 5-HT1AR could colocalize and interact in a cell and in the skin. When the N terminus of the NK1R protein was removed NK1R surface targeting was prevented, the interaction between NK1R-5-HT1AR decreased, and the depigmentation caused by SP and WAY100635 could be rescued. Importantly, pharmaceutical coadministration of NK1R agonist (SP) and 5-HT1A antagonist (WAY100635) enhanced the NK1-5-HT1A receptor coimmunoprecipitation along with the depigmentary response. SP and WAY100635 cooperation elicited activation of a signaling cascade (the extracellular, regulated protein kinase p-JNK signaling pathway) and inhibition of p70S6K1 phosphorylation and greatly reduced melanin production in vitro and in vivo in mice and zebrafish. Moreover, the SP-induced depigmentation response did not be occur in 5-htr1aa+/- zebrafish embryos. Taken together, the results of our systemic study increases our knowledge of the roles of NK1R and 5-HT1AR in melanogenesis and provides possible, novel therapeutic strategies for treatment of skin hypo/hyperpigmentation.-Wu, H., Zhao, Y., Huang, Q., Cai, M., Pan, Q., Fu, M., An, X., Xia, Z., Liu, M., Jin, Y., He, L., Shang, J. NK1R/5-HT1AR interaction is related to the regulation of melanogenesis.
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Affiliation(s)
- Huali Wu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Yucheng Zhao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Qiaoling Huang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Minxuan Cai
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Qi Pan
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Mengsi Fu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaohong An
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Zhenjiang Xia
- Qinghai Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Meng Liu
- The Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, China; and
| | - Yu Jin
- University of California, Santa Barbara, Santa Barbara, California, USA
| | - Ling He
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Jing Shang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of Traditional Chinese Medicine (TCM) Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.,Qinghai Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
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7
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Hayes MP, Bodle CR, Roman DL. Evaluation of the Selectivity and Cysteine Dependence of Inhibitors across the Regulator of G Protein-Signaling Family. Mol Pharmacol 2017; 93:25-35. [PMID: 29051318 DOI: 10.1124/mol.117.109843] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/16/2017] [Indexed: 01/03/2023] Open
Abstract
Since their discovery more than 20 years ago, regulators of G protein-signaling (RGS) proteins have received considerable attention as potential drug targets because of their ability to modulate Gα activity. Efforts to identify small molecules capable of inhibiting the protein-protein interactions between activated Gα subunits and RGS proteins have yielded a substantial number of inhibitors, especially toward the well studied RGS4. These efforts also determined that many of these small molecules inhibit the protein-protein interactions through covalent modification of cysteine residues within the RGS domain that are located distal to the Gα-binding interface. As some of these cysteine residues are highly conserved within the RGS family, many of these inhibitors display activity toward multiple RGS family members. In this work, we sought to determine the selectivity of these small-molecule inhibitors against 12 RGS proteins, as well as against the cysteine-null mutants for 10 of these proteins. Using both biochemical and cell-based methods to assess Gα-RGS complex formation and Gα enzymatic activity, we found that several previously identified RGS4 inhibitors were active against other RGS members, such as RGS14, with comparable or greater potency. Additionally, for every compound tested, activity was dependent on the presence of cysteine residues. This work defines the selectivity of commercially available RGS inhibitors and provides insight into the RGS family members for which drug discovery efforts may be most likely to succeed.
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Affiliation(s)
- Michael P Hayes
- Department of Pharmaceutical Sciences and Experimental Therapeutics University of Iowa (M.P.H., C.R.B., D.L.R.) and Cancer Signaling and Experimental Therapeutics Program, Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (D.L.R.), Iowa City, Iowa
| | - Christopher R Bodle
- Department of Pharmaceutical Sciences and Experimental Therapeutics University of Iowa (M.P.H., C.R.B., D.L.R.) and Cancer Signaling and Experimental Therapeutics Program, Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (D.L.R.), Iowa City, Iowa
| | - David L Roman
- Department of Pharmaceutical Sciences and Experimental Therapeutics University of Iowa (M.P.H., C.R.B., D.L.R.) and Cancer Signaling and Experimental Therapeutics Program, Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (D.L.R.), Iowa City, Iowa
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8
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Franco R, Martínez-Pinilla E, Navarro G, Zamarbide M. Potential of GPCRs to modulate MAPK and mTOR pathways in Alzheimer's disease. Prog Neurobiol 2017; 149-150:21-38. [PMID: 28189739 DOI: 10.1016/j.pneurobio.2017.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 01/20/2017] [Accepted: 01/22/2017] [Indexed: 02/08/2023]
Abstract
Despite efforts to understand the mechanism of neuronal cell death, finding effective therapies for neurodegenerative diseases is still a challenge. Cognitive deficits are often associated with neurodegenerative diseases. Remarkably, in the absence of consensus biomarkers, diagnosis of diseases such as Alzheimer's still relies on cognitive tests. Unfortunately, all efforts to translate findings in animal models to the patients have been unsuccessful. Alzheimer's disease may be addressed from two different points of view, neuroprotection or cognitive enhancement. Based on recent data, the mammalian target of rapamycin (mTOR) pathway arises as a versatile player whose modulation may impact on mechanisms of both neuroprotection and cognition. Whereas direct targeting of mTOR does not seem to constitute a convenient approach in drug discovery, its indirect modulation by other signaling pathways seems promising. In fact, G-protein-coupled receptors (GPCRs) remain the most common 'druggable' targets and as such pharmacological manipulation of GPCRs with selective ligands may modulate phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), mitogen-activated protein (MAP) kinase and mTOR signaling pathways. Thus, GPCRs become important targets for potential drug treatments in different neurodegenerative disorders including, but not limited to, Alzheimer's disease. GPCR-mediated modulation of mTOR may take advantage of different GPCRs coupled to different G-dependent and G-independent signal transduction routes, of functional selectivity and/or of biased agonism. Signals mediated by GPCRs may act as coincidence detectors to achieve different benefits in different stages of the neurodegenerative disease.
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Affiliation(s)
- Rafael Franco
- Department of Biochemistry and Molecular Biomedicine and IBUB (Institute of Biomedicine of the University of Barcelona), University of Barcelona, Barcelona, Spain; Centro de investigación en Red: Enfermedades Neurodegenerativas, CIBERNED, Madrid, Spain
| | - Eva Martínez-Pinilla
- Instituto de Neurociencias del Principado de Asturias (INEUROPA), Departamento de Morfología y Biología Celular, Facultad de Medicina, Universidad de Oviedo, Asturias, Spain
| | - Gemma Navarro
- Department of Biochemistry and Molecular Biomedicine and IBUB (Institute of Biomedicine of the University of Barcelona), University of Barcelona, Barcelona, Spain; Centro de investigación en Red: Enfermedades Neurodegenerativas, CIBERNED, Madrid, Spain
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9
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Hayes MP, Roman DL. Regulator of G Protein Signaling 17 as a Negative Modulator of GPCR Signaling in Multiple Human Cancers. AAPS JOURNAL 2016; 18:550-9. [PMID: 26928451 DOI: 10.1208/s12248-016-9894-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/15/2016] [Indexed: 02/08/2023]
Abstract
Regulators of G protein signaling (RGS) proteins modulate G protein-coupled receptor (GPCR) signaling networks by terminating signals produced by active Gα subunits. RGS17, a member of the RZ subfamily of RGS proteins, is typically only expressed in appreciable amounts in the human central nervous system, but previous works have shown that RGS17 expression is selectively upregulated in a number of malignancies, including lung, breast, prostate, and hepatocellular carcinoma. In addition, this upregulation of RGS17 is associated with a more aggressive cancer phenotype, as increased proliferation, migration, and invasion are observed. Conversely, decreased RGS17 expression diminishes the response of ovarian cancer cells to agents commonly used during chemotherapy. These somewhat contradictory roles of RGS17 in cancer highlight the need for selective, high-affinity inhibitors of RGS17 to use as chemical probes to further the understanding of RGS17 biology. Based on current evidence, these compounds could potentially have clinical utility as novel chemotherapeutics in the treatment of lung, prostate, breast, and liver cancers. Recent advances in screening technologies to identify potential inhibitors coupled with increasing knowledge of the structural requirements of RGS-Gα protein-protein interaction inhibitors make the future of drug discovery efforts targeting RGS17 promising. This review highlights recent findings related to RGS17 as both a canonical and atypical RGS protein, its role in various human disease states, and offers insights on small molecule inhibition of RGS17.
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Affiliation(s)
- Michael P Hayes
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, Iowa, USA
| | - David L Roman
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, Iowa, USA. .,Cancer Signaling and Experimental Therapeutics Program, Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA. .,, 115 S. Grand Avenue, S327 PHAR, Iowa City, Iowa, 52242, USA.
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10
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Biswal MR, Ahmed CM, Ildefonso CJ, Han P, Li H, Jivanji H, Mao H, Lewin AS. Systemic treatment with a 5HT1a agonist induces anti-oxidant protection and preserves the retina from mitochondrial oxidative stress. Exp Eye Res 2015; 140:94-105. [PMID: 26315784 DOI: 10.1016/j.exer.2015.07.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/22/2015] [Accepted: 07/28/2015] [Indexed: 12/31/2022]
Abstract
Chronic oxidative stress contributes to age related diseases including age related macular degeneration (AMD). Earlier work showed that the 5-hydroxy-tryptamine 1a (5HT1a) receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) protects retinal pigment epithelium (RPE) cells from hydrogen peroxide treatment and mouse retinas from oxidative insults including light injury. In our current experiments, RPE derived cells subjected to mitochondrial oxidative stress were protected from cell death by the up-regulation of anti-oxidant enzymes and of the metal ion chaperone metallothionein. Differentiated RPE cells were resistant to oxidative stress, and the expression of genes for protective proteins was highly increased by oxidative stress plus drug treatment. In mice treated with 8-OH-DPAT, the same genes (MT1, HO1, NqO1, Cat, Sod1) were induced in the neural retina, but the drug did not affect the expression of Sod2, the gene for manganese superoxide dismutase. We used a mouse strain deleted for Sod2 in the RPE to accelerate age-related oxidative stress in the retina and to test the impact of 8-OH-DPAT on the photoreceptor and RPE degeneration developed in these mice. Treatment of mice with daily injections of the drug led to increased electroretinogram (ERG) amplitudes in dark-adapted mice and to a slight improvement in visual acuity. Most strikingly, in mice treated with a high dose of the drug (5 mg/kg) the structure of the RPE and Bruch's membrane and the normal architecture of photoreceptor outer segments were preserved. These results suggest that systemic treatment with this class of drugs may be useful in preventing geographic atrophy, the advanced form of dry AMD, which is characterized by RPE degeneration.
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Affiliation(s)
- Manas R Biswal
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Chulbul M Ahmed
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Cristhian J Ildefonso
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Pingyang Han
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Hong Li
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Hiral Jivanji
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Haoyu Mao
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Box 100266, Gainesville, FL, 32610-0266, USA.
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11
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Wang Q, Chuikov S, Taitano S, Wu Q, Rastogi A, Tuck SJ, Corey JM, Lundy SK, Mao-Draayer Y. Dimethyl Fumarate Protects Neural Stem/Progenitor Cells and Neurons from Oxidative Damage through Nrf2-ERK1/2 MAPK Pathway. Int J Mol Sci 2015; 16:13885-907. [PMID: 26090715 PMCID: PMC4490529 DOI: 10.3390/ijms160613885] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 06/09/2015] [Accepted: 06/12/2015] [Indexed: 01/19/2023] Open
Abstract
Multiple sclerosis (MS) is the most common multifocal inflammatory demyelinating disease of the central nervous system (CNS). Due to the progressive neurodegenerative nature of MS, developing treatments that exhibit direct neuroprotective effects are needed. Tecfidera™ (BG-12) is an oral formulation of the fumaric acid esters (FAE), containing the active metabolite dimethyl fumarate (DMF). Although BG-12 showed remarkable efficacy in lowering relapse rates in clinical trials, its mechanism of action in MS is not yet well understood. In this study, we reported the potential neuroprotective effects of dimethyl fumarate (DMF) on mouse and rat neural stem/progenitor cells (NPCs) and neurons. We found that DMF increased the frequency of the multipotent neurospheres and the survival of NPCs following oxidative stress with hydrogen peroxide (H2O2) treatment. In addition, utilizing the reactive oxygen species (ROS) assay, we showed that DMF reduced ROS production induced by H2O2. DMF also decreased oxidative stress-induced apoptosis. Using motor neuron survival assay, DMF significantly promoted survival of motor neurons under oxidative stress. We further analyzed the expression of oxidative stress-induced genes in the NPC cultures and showed that DMF increased the expression of transcription factor nuclear factor-erythroid 2-related factor 2 (Nrf2) at both levels of RNA and protein. Furthermore, we demonstrated the involvement of Nrf2-ERK1/2 MAPK pathway in DMF-mediated neuroprotection. Finally, we utilized SuperArray gene screen technology to identify additional anti-oxidative stress genes (Gstp1, Sod2, Nqo1, Srxn1, Fth1). Our data suggests that analysis of anti-oxidative stress mechanisms may yield further insights into new targets for treatment of multiple sclerosis (MS).
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Affiliation(s)
- Qin Wang
- Department of Neurology, University of Michigan Medical School, 4015 Alfred Taubman Biomedical Sciences Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Sergei Chuikov
- Department of Neurology, University of Michigan Medical School, 4015 Alfred Taubman Biomedical Sciences Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Sophina Taitano
- Department of Internal Medicine, Division of Rheumatology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
| | - Qi Wu
- Department of Neurology, University of Michigan Medical School, 4015 Alfred Taubman Biomedical Sciences Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
| | - Arjun Rastogi
- Geriatrics Research, Education, and Clinical Center (GRECC), VA Ann Arbor Healthcare Center, Ann Arbor, MI 48109-2200, USA.
| | - Samuel J Tuck
- Geriatrics Research, Education, and Clinical Center (GRECC), VA Ann Arbor Healthcare Center, Ann Arbor, MI 48109-2200, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2200, USA.
| | - Joseph M Corey
- Department of Neurology, University of Michigan Medical School, 4015 Alfred Taubman Biomedical Sciences Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
- Geriatrics Research, Education, and Clinical Center (GRECC), VA Ann Arbor Healthcare Center, Ann Arbor, MI 48109-2200, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109-2200, USA.
| | - Steven K Lundy
- Department of Internal Medicine, Division of Rheumatology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
- Graduate Program in Immunology, Program in Biomedical Sciences, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
| | - Yang Mao-Draayer
- Department of Neurology, University of Michigan Medical School, 4015 Alfred Taubman Biomedical Sciences Research Building, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200, USA.
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Woodard GE, Jardín I, Berna-Erro A, Salido GM, Rosado JA. Regulators of G-protein-signaling proteins: negative modulators of G-protein-coupled receptor signaling. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 317:97-183. [PMID: 26008785 DOI: 10.1016/bs.ircmb.2015.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Regulators of G-protein-signaling (RGS) proteins are a category of intracellular proteins that have an inhibitory effect on the intracellular signaling produced by G-protein-coupled receptors (GPCRs). RGS along with RGS-like proteins switch on through direct contact G-alpha subunits providing a variety of intracellular functions through intracellular signaling. RGS proteins have a common RGS domain that binds to G alpha. RGS proteins accelerate GTPase and thus enhance guanosine triphosphate hydrolysis through the alpha subunit of heterotrimeric G proteins. As a result, they inactivate the G protein and quickly turn off GPCR signaling thus terminating the resulting downstream signals. Activity and subcellular localization of RGS proteins can be changed through covalent molecular changes to the enzyme, differential gene splicing, and processing of the protein. Other roles of RGS proteins have shown them to not be solely committed to being inhibitors but behave more as modulators and integrators of signaling. RGS proteins modulate the duration and kinetics of slow calcium oscillations and rapid phototransduction and ion signaling events. In other cases, RGS proteins integrate G proteins with signaling pathways linked to such diverse cellular responses as cell growth and differentiation, cell motility, and intracellular trafficking. Human and animal studies have revealed that RGS proteins play a vital role in physiology and can be ideal targets for diseases such as those related to addiction where receptor signaling seems continuously switched on.
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Affiliation(s)
- Geoffrey E Woodard
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA; Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Isaac Jardín
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - A Berna-Erro
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Gines M Salido
- Department of Physiology, University of Extremadura, Caceres, Spain
| | - Juan A Rosado
- Department of Physiology, University of Extremadura, Caceres, Spain
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