Drug addiction arises from aberrant synaptic plasticity that is induced by cocaine or other drugs of abuse. Our studies examine the molecular and cellular basis of this plasticity, and focus on adaptations mediated by cellular immediate early genes (IEG). The IEG termed Homer1a functions at excitatory synapses, and controls a newly identified signaling pathway that integrates aspects of dopamine and glutamate receptor signaling, reward-dependent synaptic plasticity, and drug addiction (1). Studies to date reveal that cocaine induces dopamine receptor-dependent intracellular signaling events that result in the transcriptional induction of Homer1a, together with the phosphorylation of group 1 metabotropic glutamate receptor type 5 (mGluR5). These coordinated events result in the binding of a prolyl isomerase termed Pin1 to mGluR5, which mediates a conformational switch that enhances the ability of mGluR5 to activate the NMDA receptor. We term this the mGluR5-Pin1 signaling pathway. Using a combination of approaches, we find that this pathway mediates synaptic plasticity that underlies cocaine motor sensitization. We hypothesize this pathway contributes to several forms of neuromodulator-dependent synaptic plasticity, and is a fundamental mechanism to modulate NMDA receptor function. The renewal application will examine the molecular basis of mGluR5-Pin1 coupling to NMDA receptor. Studies will assess the role of mGluR directed scaffolding proteins and the role of intracellular Ca2+ stores. We will also define how the Pin1 mechanism regulates mGluR1 gating to TRPC ion channels, and assess the contribution of mGluR-Pin1 signaling to cocaine-induced plasticity.

Public Health Relevance

This proposal examines the molecular and cellular basis of drug addiction. The work focuses on a novel signaling pathway that is controlled by the immediate early gene Homer1a, and that involves group 1 metabotropic glutamate receptors to mediate dopamine receptor-dependent synaptic plasticity. Proposed studies will define the molecular mechanism of signal transduction and the impact on behavioral models important for understanding addiction.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA010309-23
Application #
9745562
Study Section
Molecular Neuropharmacology and Signaling Study Section (MNPS)
Program Officer
Lossie, Amy C
Project Start
1996-05-20
Project End
2020-07-31
Budget Start
2019-08-01
Budget End
2020-07-31
Support Year
23
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205
Piard, Juliette; Hu, Jia-Hua; Campeau, Philippe M et al. (2018) FRMPD4 mutations cause X-linked intellectual disability and disrupt dendritic spine morphogenesis. Hum Mol Genet 27:589-600
Hu, Jia-Hua; Worley, Paul F; Kammermeier, Paul J (2017) Dynamic Regulation of Homer Binding to Group I Metabotropic Glutamate Receptors by Preso1 and Converging Kinase Cascades. J Pharmacol Exp Ther 361:122-129
Ryu, Changhyeon; Jang, Dong Cheol; Jung, Dayoon et al. (2017) STIM1 Regulates Somatic Ca2+ Signals and Intrinsic Firing Properties of Cerebellar Purkinje Neurons. J Neurosci 37:8876-8894
Datko, Michael C; Hu, Jia-Hua; Williams, Melanie et al. (2017) Behavioral and Neurochemical Phenotyping of Mice Incapable of Homer1a Induction. Front Behav Neurosci 11:208
Ahuja, Malini; Schwartz, Daniella M; Tandon, Mayank et al. (2017) Orai1-Mediated Antimicrobial Secretion from Pancreatic Acini Shapes the Gut Microbiome and Regulates Gut Innate Immunity. Cell Metab 25:635-646
Diering, Graham H; Nirujogi, Raja S; Roth, Richard H et al. (2017) Homer1a drives homeostatic scaling-down of excitatory synapses during sleep. Science 355:511-515
Cozzoli, Debra K; Courson, Justin; Rostock, Charlotte et al. (2016) Protein Kinase C Epsilon Activity in the Nucleus Accumbens and Central Nucleus of the Amygdala Mediates Binge Alcohol Consumption. Biol Psychiatry 79:443-51
Marton, Tanya M; Hussain Shuler, Marshall G; Worley, Paul F (2015) Homer 1a and mGluR5 phosphorylation in reward-sensitive metaplasticity: A hypothesis of neuronal selection and bidirectional synaptic plasticity. Brain Res 1628:17-28
Obara, Ilona; Goulding, Scott P; Hu, Jia-Hua et al. (2013) Nerve injury-induced changes in Homer/glutamate receptor signaling contribute to the development and maintenance of neuropathic pain. Pain 154:1932-45
Park, Joo Min; Hu, Jia-Hua; Milshteyn, Aleksandr et al. (2013) A prolyl-isomerase mediates dopamine-dependent plasticity and cocaine motor sensitization. Cell 154:637-50

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