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Alcohol Use Disorder: Neurobiology and Therapeutics. Biomedicines 2022; 10:biomedicines10051192. [PMID: 35625928 PMCID: PMC9139063 DOI: 10.3390/biomedicines10051192] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 02/04/2023] Open
Abstract
Alcohol use disorder (AUD) encompasses the dysregulation of multiple brain circuits involved in executive function leading to excessive consumption of alcohol, despite negative health and social consequences and feelings of withdrawal when access to alcohol is prevented. Ethanol exerts its toxicity through changes to multiple neurotransmitter systems, including serotonin, dopamine, gamma-aminobutyric acid, glutamate, acetylcholine, and opioid systems. These neurotransmitter imbalances result in dysregulation of brain circuits responsible for reward, motivation, decision making, affect, and the stress response. Despite serious health and psychosocial consequences, this disorder still remains one of the leading causes of death globally. Treatment options include both psychological and pharmacological interventions, which are aimed at reducing alcohol consumption and/or promoting abstinence while also addressing dysfunctional behaviours and impaired functioning. However, stigma and social barriers to accessing care continue to impact many individuals. AUD treatment should focus not only on restoring the physiological and neurological impairment directly caused by alcohol toxicity but also on addressing psychosocial factors associated with AUD that often prevent access to treatment. This review summarizes the impact of alcohol toxicity on brain neurocircuitry in the context of AUD and discusses pharmacological and non-pharmacological therapies currently available to treat this addiction disorder.
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OUP accepted manuscript. Hum Mol Genet 2022; 31:2236-2261. [DOI: 10.1093/hmg/ddac029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 11/12/2022] Open
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You Y, Das J. Effect of ethanol on Munc13-1 C1 in Membrane: A Molecular Dynamics Simulation Study. Alcohol Clin Exp Res 2020; 44:1344-1355. [PMID: 32424866 DOI: 10.1111/acer.14363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 05/06/2020] [Indexed: 12/26/2022]
Abstract
BACKGROUND EtOH has a significant effect on synaptic plasticity. Munc13-1 is an essential presynaptic active zone protein involved in priming the synaptic vesicle and releasing neurotransmitter in the brain. It is a peripheral membrane protein and binds to the activator, diacylglycerol (DAG)/phorbol ester at its membrane-targeting C1 domain. Our previous studies identified Glu-582 of C1 domain as the alcohol-binding residue (Das, J. et al, J. Neurochem., 126, 715-726, 2013). METHODS Here, we describe a 250 ns molecular dynamics (MD) simulation study on the interaction of EtOH and the activator-bound Munc13-1 C1 in the presence of varying concentrations of phosphatidylserine (PS). RESULTS In this study, Munc13-1 C1 shows higher conformational stability in EtOH than in water. It forms fewer hydrogen bonds with phorbol 13-acetate in the presence of EtOH than in water. EtOH also affected the interaction between the protein and the membrane and between the activator and the membrane. Similar studies in a E582A mutant suggest that these effects of EtOH are mostly mediated through Glu-582. CONCLUSIONS EtOH forms hydrogen bonds with Glu-582. While occupancy of the EtOH molecules at the vicinity (4Å) of Glu-582 is 34.4%, the occupancy in the E582A mutant is 26.5% of the simulation time. In addition, the amount of PS in the membrane influences the conformational stability of the C1 domain and interactions in the ternary complex. This study is important in providing the structural basis of EtOH's effects on synaptic plasticity.
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Affiliation(s)
- Youngki You
- From the Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
| | - Joydip Das
- From the Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
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Yamada A, Koga K, Kume K, Ohsawa M, Furue H. Ethanol-induced enhancement of inhibitory synaptic transmission in the rat spinal substantia gelatinosa. Mol Pain 2018; 14:1744806918817969. [PMID: 30453825 PMCID: PMC6293375 DOI: 10.1177/1744806918817969] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Recent studies have shown that ethanol produces a widespread modulation
of neuronal activity in the central nervous system. It is not fully
understood, however, how ethanol changes nociceptive transmission. We
investigated acute effects of ethanol on synaptic transmission in the
substantia gelatinosa (lamina II of the spinal dorsal horn) and
mechanical responses in the spinal dorsal horn. In substantia
gelatinosa neurons, bath application of ethanol at low concentration
(10 mM) did not change the frequency and amplitude of spontaneous
inhibitory postsynaptic currents. At medium to high concentrations
(20–100 mM), however, ethanol elicited a barrage of large amplitude
spontaneous inhibitory postsynaptic currents. In the presence of
tetrodotoxin, such enhancement of spontaneous inhibitory postsynaptic
currents was not detected. In addition, ethanol (20–100 mM) increased
the frequency of spontaneous discharge of vesicular GABA
transporter-Venus-labeled neurons and suppressed the mechanical
nociceptive response in wide-dynamic range neurons in the spinal
dorsal horn. The present results suggest that ethanol may reduce
nociceptive information transfer in the spinal dorsal horn by
enhancement of inhibitory GABAergic and glycinergic synaptic
transmission.
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Affiliation(s)
- Akihiro Yamada
- Department of Neurophysiology, Hyogo College of
Medicine, Nishinomiya, Japan
- Department of Neuropharmacology, Graduate School of
Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
- Department of Information Physiology, National
Institute for Physiological Sciences, Okazaki, Japan
| | - Kohei Koga
- Department of Neurophysiology, Hyogo College of
Medicine, Nishinomiya, Japan
| | - Kazuhiko Kume
- Department of Neuropharmacology, Graduate School of
Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Masahiro Ohsawa
- Department of Neuropharmacology, Graduate School of
Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of
Medicine, Nishinomiya, Japan
- Department of Information Physiology, National
Institute for Physiological Sciences, Okazaki, Japan
- School of Life Science, Graduate University for
Advanced Studies, Okazaki, Japan
- Hidemasa Furue, Department of
Neurophysiology 663–8131, Hyogo College of Medicine, Nishinomiya,
Japan.
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Das J. Identification of alcohol-binding site(s) in proteins using diazirine-based photoaffinity labeling and mass spectrometry. Chem Biol Drug Des 2018; 93:1158-1165. [PMID: 30346111 DOI: 10.1111/cbdd.13403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/03/2018] [Accepted: 09/15/2018] [Indexed: 01/12/2023]
Abstract
Defining molecular targets of alcohol and understanding the molecular mechanism of alcohol actions are necessary to develop effective therapeutics for alcohol use disorder (AUD). Here, we describe a detailed protocol for identifying alcohol-binding site(s) in proteins using diazirine-based azialcohol as photoaffinity labeling agents. Upon photoirradiation, azialcohol photoincorporates into alcohol-binding proteins. The stoichiometry and site of azialcohol photoincorporation can be determined using high-resolution mass spectrometry. Identification of the alcohol-binding residues in protein followed by measuring the biological significance of these residues in regulating alcohol action are important steps in characterizing the molecular targets of alcohol.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas
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Morel C, Montgomery S, Han MH. Nicotine and alcohol: the role of midbrain dopaminergic neurons in drug reinforcement. Eur J Neurosci 2018; 50:2180-2200. [PMID: 30251377 DOI: 10.1111/ejn.14160] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/31/2018] [Accepted: 08/20/2018] [Indexed: 12/11/2022]
Abstract
Nicotine and alcohol addiction are leading causes of preventable death worldwide and continue to constitute a huge socio-economic burden. Both nicotine and alcohol perturb the brain's mesocorticolimbic system. Dopamine (DA) neurons projecting from the ventral tegmental area (VTA) to multiple downstream structures, including the nucleus accumbens, prefrontal cortex, and amygdala, are highly involved in the maintenance of healthy brain function. VTA DA neurons play a crucial role in associative learning and reinforcement. Nicotine and alcohol usurp these functions, promoting reinforcement of drug taking behaviors. In this review, we will first describe how nicotine and alcohol individually affect VTA DA neurons by examining how drug exposure alters the heterogeneous VTA microcircuit and network-wide projections. We will also examine how coadministration or previous exposure to nicotine or alcohol may augment the reinforcing effects of the other. Additionally, this review briefly summarizes the role of VTA DA neurons in nicotine, alcohol, and their synergistic effects in reinforcement and also addresses the remaining questions related to the circuit-function specificity of the dopaminergic system in mediating nicotine/alcohol reinforcement and comorbidity.
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Affiliation(s)
- Carole Morel
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah Montgomery
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, Icahn Building Floor 12 Room 12-75B, 1425 Madison Ave, New York, NY 10029, USA.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Ethanol Regulates Presynaptic Activity and Sedation through Presynaptic Unc13 Proteins in Drosophila. eNeuro 2018; 5:eN-NWR-0125-18. [PMID: 29911175 PMCID: PMC6001265 DOI: 10.1523/eneuro.0125-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/09/2018] [Accepted: 05/12/2018] [Indexed: 11/21/2022] Open
Abstract
Ethanol has robust effects on presynaptic activity in many neurons, however, it is not yet clear how this drug acts within this compartment to change neural activity, nor the significance of this change on behavior and physiology in vivo. One possible presynaptic effector for ethanol is the Munc13-1 protein. Herein, we show that ethanol binding to the rat Munc13-1 C1 domain, at concentrations consistent with binge exposure, reduces diacylglycerol (DAG) binding. The inhibition of DAG binding is predicted to reduce the activity of Munc13-1 and presynaptic release. In Drosophila, we show that sedating concentrations of ethanol significantly reduce synaptic vesicle release in olfactory sensory neurons (OSNs), while having no significant impact on membrane depolarization and Ca2+ influx into the presynaptic compartment. These data indicate that ethanol targets the active zone in reducing synaptic vesicle exocytosis. Drosophila, haploinsufficent for the Munc13-1 ortholog Dunc13, are more resistant to the effect of ethanol on presynaptic inhibition. Genetically reducing the activity of Dunc13 through mutation or expression of RNAi transgenes also leads to a significant resistance to the sedative effects of ethanol. The neuronal expression of Munc13-1 in heterozygotes for a Dunc13 loss-of-function mutation can largely rescue the ethanol sedation resistance phenotype, indicating a conservation of function between Munc13-1 and Dunc13 in ethanol sedation. Hence, reducing Dunc13 activity leads to naïve physiological and behavioral resistance to sedating concentrations of ethanol. We propose that reducing Dunc13 activity, genetically or pharmacologically by ethanol binding to the C1 domain of Munc13-1/Dunc13, promotes a homeostatic response that leads to ethanol tolerance.
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Pakri Mohamed RM, Mokhtar MH, Yap E, Hanim A, Abdul Wahab N, Jaffar FHF, Kumar J. Ethanol-Induced Changes in PKCε: From Cell to Behavior. Front Neurosci 2018; 12:244. [PMID: 29706864 PMCID: PMC5907685 DOI: 10.3389/fnins.2018.00244] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/28/2018] [Indexed: 11/20/2022] Open
Abstract
The long-term binge intake of ethanol causes neuroadaptive changes that lead to drinkers requiring higher amounts of ethanol to experience its effects. This neuroadaptation can be partly attributed to the modulation of numerous neurotransmitter receptors by the various protein kinases C (PKCs). PKCs are enzymes that control cellular activities by regulating other proteins via phosphorylation. Among the various isoforms of PKC, PKCε is the most implicated in ethanol-induced biochemical and behavioral changes. Ethanol exposure causes changes to PKCε expression and localization in various brain regions that mediate addiction-favoring plasticity. Ethanol works in conjunction with numerous upstream kinases and second messenger activators to affect cellular PKCε expression. Chauffeur proteins, such as receptors for activated C kinase (RACKs), cause the translocation of PKCε to aberrant sites and mediate ethanol-induced changes. In this article, we aim to review the following: the general structure and function of PKCε, ethanol-induced changes in PKCε expression, the regulation of ethanol-induced PKCε activities in DAG-dependent and DAG-independent environments, the mechanisms underlying PKCε-RACKε translocation in the presence of ethanol, and the existing literature on the role of PKCε in ethanol-induced neurobehavioral changes, with the goal of creating a working model upon which further research can build.
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Affiliation(s)
| | - Mohd H. Mokhtar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Ernie Yap
- Department of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Athirah Hanim
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Norhazlina Abdul Wahab
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Farah H. F. Jaffar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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Abrahao KP, Salinas AG, Lovinger DM. Alcohol and the Brain: Neuronal Molecular Targets, Synapses, and Circuits. Neuron 2017; 96:1223-1238. [PMID: 29268093 PMCID: PMC6566861 DOI: 10.1016/j.neuron.2017.10.032] [Citation(s) in RCA: 243] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/30/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
Ethanol is one of the most commonly abused drugs. Although environmental and genetic factors contribute to the etiology of alcohol use disorders, it is ethanol's actions in the brain that explain (1) acute ethanol-related behavioral changes, such as stimulant followed by depressant effects, and (2) chronic changes in behavior, including escalated use, tolerance, compulsive seeking, and dependence. Our knowledge of ethanol use and abuse thus relies on understanding its effects on the brain. Scientists have employed both bottom-up and top-down approaches, building from molecular targets to behavioral analyses and vice versa, respectively. This review highlights current progress in the field, focusing on recent and emerging molecular, cellular, and circuit effects of the drug that impact ethanol-related behaviors. The focus of the field is now on pinpointing which molecular effects in specific neurons within a brain region contribute to behavioral changes across the course of acute and chronic ethanol exposure.
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Affiliation(s)
- Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - Armando G Salinas
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA
| | - David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892, USA.
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Pany S, Ghosh A, You Y, Nguyen N, Das J. Resveratrol inhibits phorbol ester-induced membrane translocation of presynaptic Munc13-1. Biochim Biophys Acta Gen Subj 2017; 1861:2640-2651. [PMID: 28713022 DOI: 10.1016/j.bbagen.2017.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/23/2017] [Accepted: 07/12/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Resveratrol (1) is a naturally occurring polyphenol that has been implicated in neuroprotection. One of resveratrol's several biological targets is Ca2+-sensitive protein kinase C alpha (PKCα). Resveratrol inhibits PKCα by binding to its activator-binding C1 domain. Munc13-1 is a C1 domain-containing Ca2+-sensitive SNARE complex protein essential for vesicle priming and neurotransmitter release. METHODS To test if resveratrol could also bind and inhibit Munc13-1, we studied the interaction of resveratrol and its derivatives, (E)-1,3-dimethoxy-5-(4-methoxystyryl)benzene, (E)-5,5'-(ethene-1,2-diyl)bis(benzene-1,2,3-triol), (E)-1,2-bis(3,4,5-trimethoxyphenyl)ethane, and (E)-5-(4-(hexadecyloxy)-3,5-dihydroxystyryl)benzene-1,2,3-triol with Munc13-1 by studying its membrane translocation from cytosol to plasma membrane in HT22 cells and primary hippocampal neurons. RESULTS Resveratrol, but not the derivatives inhibited phorbol ester-induced Munc13-1 translocation from cytosol to membrane in HT22 cells and primary hippocampal neurons, as evidenced by immunoblot analysis and confocal microscopy. Resveratrol did not show any effect on Munc13-1H567K, a mutant which is not sensitive to phorbol ester. Binding studies with Munc13-1 C1 indicated that resveratrol competes with phorbol ester for the binding site. Molecular docking and dynamics studies suggested that hydroxyl groups of resveratrol interact with phorbol-ester binding residues in the binding pocket. CONCLUSIONS AND SIGNIFICANCE This study characterizes Munc13-1 as a target of resveratrol and highlights the importance of dietary polyphenol in the management of neurodegenerative diseases.
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Affiliation(s)
- Satyabrata Pany
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Anamitra Ghosh
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Youngki You
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Nga Nguyen
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States
| | - Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
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Woll KA, Dailey WP, Brannigan G, Eckenhoff RG. Shedding Light on Anesthetic Mechanisms: Application of Photoaffinity Ligands. Anesth Analg 2017; 123:1253-1262. [PMID: 27464974 DOI: 10.1213/ane.0000000000001365] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Anesthetic photoaffinity ligands have had an increasing presence within anesthesiology research. These ligands mimic parent general anesthetics and allow investigators to study anesthetic interactions with receptors and enzymes; identify novel targets; and determine distribution within biological systems. To date, nearly all general anesthetics used in medicine have a corresponding photoaffinity ligand represented in the literature. In this review, we examine all aspects of the current methodologies, including ligand design, characterization, and deployment. Finally we offer points of consideration and highlight the future outlook as more photoaffinity ligands emerge within the field.
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Affiliation(s)
- Kellie A Woll
- From the Departments of *Anesthesiology and Critical Care and †Pharmacology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; ‡Department of Chemistry, University of Pennsylvania School of Arts and Sciences, Philadelphia, Pennsylvania; and §Department of Physics, Rutgers University, Camden, New Jersey
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Pany S, You Y, Das J. Curcumin Inhibits Protein Kinase Cα Activity by Binding to Its C1 Domain. Biochemistry 2016; 55:6327-6336. [PMID: 27776404 DOI: 10.1021/acs.biochem.6b00932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Curcumin is a polyphenolic nutraceutical that acts on multiple biological targets, including protein kinase C (PKC). PKC is a family of serine/threonine kinases central to intracellular signal transduction. We have recently shown that curcumin selectively inhibits PKCα, but not PKCε, in CHO-K1 cells [Pany, S. (2016) Biochemistry 55, 2135-2143]. To understand which domain(s) of PKCα is responsible for curcumin binding and inhibitory activity, we made several domain-swapped mutants in which the C1 (combination of C1A and C1B) and C2 domains are swapped between PKCα and PKCε. Phorbol ester-induced membrane translocation studies using confocal microscopy and immunoblotting revealed that curcumin inhibited phorbol ester-induced membrane translocation of PKCε mutants, in which the εC1 domain was replaced with αC1, but not the PKCα mutant in which αC1 was replaced with the εC1 domain, suggesting that αC1 is a determinant for curcumin's inhibitory effect. In addition, curcumin inhibited membrane translocation of PKCε mutants, in which the εC1A and εC1B domains were replaced with the αC1A and αC1B domains, respectively, indicating the role of both αC1A and αC1B domains in curcumin's inhibitory effects. Phorbol 13-acetate inhibited the binding of curcumin to αC1A and αC1B with IC50 values of 6.27 and 4.47 μM, respectively. Molecular docking and molecular dynamics studies also supported the higher affinity of curcumin for αC1B than for αC1A. The C2 domain-swapped mutants were inactive in phorbol ester-induced membrane translocation. These results indicate that curcumin binds to the C1 domain of PKCα and highlight the importance of this domain in achieving PKC isoform selectivity.
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Affiliation(s)
- Satyabrata Pany
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Youngki You
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
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Abstract
Despite increased awareness, prevention campaigns, and tighter laws and regulations, alcohol consumption caused an average of 88,000 deaths per year and a burden of $249 billion to the U.S economy in 2010. Only three FDA-approved drugs, disulfiram, naltrexone and acamprosate are available for the treatment of alcohol use disorder. These drugs are only effective modestly and patient compliance is a serious issue because of several adverse side effects, necessitating the developments of newer drugs. The current research drug development efforts remains in the identification new alcohol targets and elucidating the molecular mechanism of its action is needed for effective intervention. In addition, current treatment could be improved by testing the existing medications for comorbid conditions using the patient’s genetic background information.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, US
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