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Nature Methods Nov 2020Dopamine (DA) plays a critical role in the brain, and the ability to directly measure dopaminergic activity is essential for understanding its physiological functions....
Dopamine (DA) plays a critical role in the brain, and the ability to directly measure dopaminergic activity is essential for understanding its physiological functions. We therefore developed red fluorescent G-protein-coupled receptor-activation-based DA (GRAB) sensors and optimized versions of green fluorescent GRAB sensors. In response to extracellular DA, both the red and green GRAB sensors exhibit a large increase in fluorescence, with subcellular resolution, subsecond kinetics and nanomolar-to-submicromolar affinity. Moreover, the GRAB sensors resolve evoked DA release in mouse brain slices, detect evoked compartmental DA release from a single neuron in live flies and report optogenetically elicited nigrostriatal DA release as well as mesoaccumbens dopaminergic activity during sexual behavior in freely behaving mice. Coexpressing red GRAB with either green GRAB or the calcium indicator GCaMP6s allows tracking of dopaminergic signaling and neuronal activity in distinct circuits in vivo.
Topics: Animals; Biosensing Techniques; Brain; Dopamine; Drosophila; Green Fluorescent Proteins; HEK293 Cells; Humans; Luminescent Proteins; Mice; Neurons; Rats; Receptors, Dopamine; Receptors, G-Protein-Coupled; Sexual Behavior; Red Fluorescent Protein
PubMed: 33087905
DOI: 10.1038/s41592-020-00981-9 -
Cell Feb 2021The D1- and D2-dopamine receptors (D1R and D2R), which signal through G and G, respectively, represent the principal stimulatory and inhibitory dopamine receptors in the...
The D1- and D2-dopamine receptors (D1R and D2R), which signal through G and G, respectively, represent the principal stimulatory and inhibitory dopamine receptors in the central nervous system. D1R and D2R also represent the main therapeutic targets for Parkinson's disease, schizophrenia, and many other neuropsychiatric disorders, and insight into their signaling is essential for understanding both therapeutic and side effects of dopaminergic drugs. Here, we report four cryoelectron microscopy (cryo-EM) structures of D1R-G and D2R-G signaling complexes with selective and non-selective dopamine agonists, including two currently used anti-Parkinson's disease drugs, apomorphine and bromocriptine. These structures, together with mutagenesis studies, reveal the conserved binding mode of dopamine agonists, the unique pocket topology underlying ligand selectivity, the conformational changes in receptor activation, and potential structural determinants for G protein-coupling selectivity. These results provide both a molecular understanding of dopamine signaling and multiple structural templates for drug design targeting the dopaminergic system.
Topics: 2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; Amino Acid Sequence; Conserved Sequence; Cryoelectron Microscopy; Cyclic AMP; GTP-Binding Proteins; HEK293 Cells; Humans; Ligands; Models, Molecular; Mutant Proteins; Receptors, Adrenergic, beta-2; Receptors, Dopamine D1; Receptors, Dopamine D2; Signal Transduction; Structural Homology, Protein
PubMed: 33571431
DOI: 10.1016/j.cell.2021.01.027 -
Cell Feb 2021Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney...
Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney diseases. Here, we present five cryoelectron microscopy (cryo-EM) structures of the dopamine D1 receptor (DRD1) coupled to Gs heterotrimer in complex with three catechol-based agonists, a non-catechol agonist, and a positive allosteric modulator for endogenous dopamine. These structures revealed that a polar interaction network is essential for catecholamine-like agonist recognition, whereas specific motifs in the extended binding pocket were responsible for discriminating D1- from D2-like receptors. Moreover, allosteric binding at a distinct inner surface pocket improved the activity of DRD1 by stabilizing endogenous dopamine interaction at the orthosteric site. DRD1-Gs interface revealed key features that serve as determinants for G protein coupling. Together, our study provides a structural understanding of the ligand recognition, allosteric regulation, and G protein coupling mechanisms of DRD1.
Topics: Allosteric Regulation; Allosteric Site; Amino Acid Motifs; Amino Acid Sequence; Binding Sites; Catechols; Cryoelectron Microscopy; Fenoldopam; GTP-Binding Protein alpha Subunits, Gs; HEK293 Cells; Humans; Ligands; Models, Molecular; Protein Multimerization; Receptors, Dopamine D1; Receptors, Dopamine D2; Signal Transduction; Structural Homology, Protein
PubMed: 33571432
DOI: 10.1016/j.cell.2021.01.028 -
Cell Research Aug 2023The dopaminergic system, including five dopamine receptors (D1R to D5R), plays essential roles in the central nervous system (CNS); and ligands that activate dopamine...
The dopaminergic system, including five dopamine receptors (D1R to D5R), plays essential roles in the central nervous system (CNS); and ligands that activate dopamine receptors have been used to treat many neuropsychiatric disorders, including Parkinson's Disease (PD) and schizophrenia. Here, we report cryo-EM structures of all five subtypes of human dopamine receptors in complex with G protein and bound to the pan-agonist, rotigotine, which is used to treat PD and restless legs syndrome. The structures reveal the basis of rotigotine recognition in different dopamine receptors. Structural analysis together with functional assays illuminate determinants of ligand polypharmacology and selectivity. The structures also uncover the mechanisms of dopamine receptor activation, unique structural features among the five receptor subtypes, and the basis of G protein coupling specificity. Our work provides a comprehensive set of structural templates for the rational design of specific ligands to treat CNS diseases targeting the dopaminergic system.
Topics: Humans; Receptors, Dopamine; Ligands; Dopamine; Parkinson Disease; Genomics
PubMed: 37221270
DOI: 10.1038/s41422-023-00808-0 -
Translational Psychiatry Sep 2022Social isolation and discrimination are growing public health concerns associated with poor physical and mental health. They are risk factors for increased morbidity and... (Review)
Review
Social isolation and discrimination are growing public health concerns associated with poor physical and mental health. They are risk factors for increased morbidity and mortality and reduced quality of life. Despite their detrimental effects on health, there is a lack of knowledge regarding translation across the domains of experimental research, clinical studies, and real-life applications. Here, we review and synthesize evidence from basic research in animals and humans to clinical translation and interventions. Animal models indicate that social separation stress, particularly in early life, activates the hypothalamic-pituitary-adrenal axis and interacts with monoaminergic, glutamatergic, and GABAergic neurotransmitter systems, inducing long-lasting reductions in serotonin turnover and alterations in dopamine receptor sensitivity. These findings are of particular importance for human social isolation stress, as effects of social isolation stress on the same neurotransmitter systems have been implicated in addictive, psychotic, and affective disorders. Children may be particularly vulnerable due to lasting effects of social isolation and discrimination stress on the developing brain. The effects of social isolation and loneliness are pronounced in the context of social exclusion due to discrimination and racism, during widespread infectious disease related containment strategies such as quarantine, and in older persons due to sociodemographic changes. This highlights the importance of new strategies for social inclusion and outreach, including gender, culture, and socially sensitive telemedicine and digital interventions for mental health care.
Topics: Aged; Animals; Child; Humans; Hypothalamo-Hypophyseal System; Mental Health; Neurotransmitter Agents; Pituitary-Adrenal System; Quality of Life; Receptors, Dopamine; Serotonin; Social Isolation
PubMed: 36130935
DOI: 10.1038/s41398-022-02178-4 -
Immunity Dec 2023Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less...
Although the gut microbiota can influence central nervous system (CNS) autoimmune diseases, the contribution of the intestinal epithelium to CNS autoimmunity is less clear. Here, we showed that intestinal epithelial dopamine D2 receptors (IEC DRD2) promoted sex-specific disease progression in an animal model of multiple sclerosis. Female mice lacking Drd2 selectively in intestinal epithelial cells showed a blunted inflammatory response in the CNS and reduced disease progression. In contrast, overexpression or activation of IEC DRD2 by phenylethylamine administration exacerbated disease severity. This was accompanied by altered lysozyme expression and gut microbiota composition, including reduced abundance of Lactobacillus species. Furthermore, treatment with N2-acetyl-L-lysine, a metabolite derived from Lactobacillus, suppressed microglial activation and neurodegeneration. Taken together, our study indicates that IEC DRD2 hyperactivity impacts gut microbial abundances and increases susceptibility to CNS autoimmune diseases in a female-biased manner, opening up future avenues for sex-specific interventions of CNS autoimmune diseases.
Topics: Male; Female; Mice; Animals; Multiple Sclerosis; Disease Models, Animal; Signal Transduction; Autoimmune Diseases of the Nervous System; Disease Progression; Receptors, Dopamine
PubMed: 37992711
DOI: 10.1016/j.immuni.2023.10.016 -
Nature Neuroscience Aug 2023Elevated dopamine transmission in psychosis is assumed to unbalance striatal output through D1- and D2-receptor-expressing spiny-projection neurons (SPNs). Antipsychotic...
Elevated dopamine transmission in psychosis is assumed to unbalance striatal output through D1- and D2-receptor-expressing spiny-projection neurons (SPNs). Antipsychotic drugs are thought to re-balance this output by blocking D2 receptors (D2Rs). In this study, we found that amphetamine-driven dopamine release unbalanced D1-SPN and D2-SPN Ca activity in mice, but that antipsychotic efficacy was associated with the reversal of abnormal D1-SPN, rather than D2-SPN, dynamics, even for drugs that are D2R selective or lacking any dopamine receptor affinity. By contrast, a clinically ineffective drug normalized D2-SPN dynamics but exacerbated D1-SPN dynamics under hyperdopaminergic conditions. Consistent with antipsychotic effect, selective D1-SPN inhibition attenuated amphetamine-driven changes in locomotion, sensorimotor gating and hallucination-like perception. Notably, antipsychotic efficacy correlated with the selective inhibition of D1-SPNs only under hyperdopaminergic conditions-a dopamine-state-dependence exhibited by D1R partial agonism but not non-antipsychotic D1R antagonists. Our findings provide new insights into antipsychotic drug mechanism and reveal an important role for D1-SPN modulation.
Topics: Mice; Animals; Antipsychotic Agents; Dopamine; Corpus Striatum; Neurons; Interneurons; Receptors, Dopamine D2; Receptors, Dopamine D1
PubMed: 37443282
DOI: 10.1038/s41593-023-01390-9 -
International Journal of Molecular... Nov 2020The renal dopaminergic system has been identified as a modulator of sodium balance and blood pressure. According to the Centers for Disease Control and Prevention, in... (Review)
Review
The renal dopaminergic system has been identified as a modulator of sodium balance and blood pressure. According to the Centers for Disease Control and Prevention, in 2018 in the United States, almost half a million deaths included hypertension as a primary or contributing cause. Renal dopamine receptors, members of the G protein-coupled receptor family, are divided in two groups: D1-like receptors that act to keep the blood pressure in the normal range, and D2-like receptors with a variable effect on blood pressure, depending on volume status. The renal dopamine receptor function is regulated, in part, by its expression in microdomains in the plasma membrane. Lipid rafts form platforms within the plasma membrane for the organization and dynamic contact of molecules involved in numerous cellular processes such as ligand binding, membrane sorting, effector specificity, and signal transduction. Understanding all the components of lipid rafts, their interaction with renal dopamine receptors, and their signaling process offers an opportunity to unravel potential treatment targets that could halt the progression of hypertension, chronic kidney disease (CKD), and their complications.
Topics: Blood Pressure; Cell Membrane; Dopamine; Humans; Hypertension; Kidney; Membrane Microdomains; Receptors, Dopamine D1; Receptors, Dopamine D2; Signal Transduction; Sodium
PubMed: 33255376
DOI: 10.3390/ijms21238909 -
Advanced Materials (Deerfield Beach,... Jan 2022Following treatment with androgen receptor (AR) pathway inhibitors, ≈20% of prostate cancer patients progress by shedding their AR-dependence. These tumors undergo...
Following treatment with androgen receptor (AR) pathway inhibitors, ≈20% of prostate cancer patients progress by shedding their AR-dependence. These tumors undergo epigenetic reprogramming turning castration-resistant prostate cancer adenocarcinoma (CRPC-Adeno) into neuroendocrine prostate cancer (CRPC-NEPC). No targeted therapies are available for CRPC-NEPCs, and there are minimal organoid models to discover new therapeutic targets against these aggressive tumors. Here, using a combination of patient tumor proteomics, RNA sequencing, spatial-omics, and a synthetic hydrogel-based organoid, putative extracellular matrix (ECM) cues that regulate the phenotypic, transcriptomic, and epigenetic underpinnings of CRPC-NEPCs are defined. Short-term culture in tumor-expressed ECM differentially regulated DNA methylation and mobilized genes in CRPC-NEPCs. The ECM type distinctly regulates the response to small-molecule inhibitors of epigenetic targets and Dopamine Receptor D2 (DRD2), the latter being an understudied target in neuroendocrine tumors. In vivo patient-derived xenograft in immunocompromised mice showed strong anti-tumor response when treated with a DRD2 inhibitor. Finally, we demonstrate that therapeutic response in CRPC-NEPCs under drug-resistant ECM conditions can be overcome by first cellular reprogramming with epigenetic inhibitors, followed by DRD2 treatment. The synthetic organoids suggest the regulatory role of ECM in therapeutic response to targeted therapies in CRPC-NEPCs and enable the discovery of therapies to overcome resistance.
Topics: Androgen Receptor Antagonists; Animals; Cell Line, Tumor; Enhancer of Zeste Homolog 2 Protein; Extracellular Matrix; Humans; Hydrogels; Male; Mice; Organoids; Prostatic Neoplasms, Castration-Resistant; Receptors, Dopamine D2
PubMed: 34676924
DOI: 10.1002/adma.202100096 -
Frontiers in Endocrinology 2022The functional and pharmacological significance of the dopamine D receptor (DR) has remained the least well understood of all the dopamine receptor subtypes. Even more... (Review)
Review
The functional and pharmacological significance of the dopamine D receptor (DR) has remained the least well understood of all the dopamine receptor subtypes. Even more enigmatic has been the role of the very prevalent human gene polymorphisms in the region that encodes the third intracellular loop of the receptor. The most common polymorphisms encode a DR with 4 or 7 repeats of a proline-rich sequence of 16 amino acids (DR and DR). polymorphisms have been associated with individual differences linked to impulse control-related neuropsychiatric disorders, with the most consistent associations established between the gene encoding DR and attention-deficit hyperactivity disorder (ADHD) and substance use disorders. The function of DR and its polymorphic variants is being revealed by addressing the role of receptor heteromerization and the relatively avidity of norepinephrine for DR. We review the evidence conveying a significant and differential role of DR and DR in the dopaminergic and noradrenergic modulation of the frontal cortico-striatal pyramidal neuron, with implications for the moderation of constructs of impulsivity as personality traits. This differential role depends on their ability to confer different properties to adrenergic α receptor (αR)-DR heteromers and dopamine D receptor (DR)-DR heteromers, preferentially localized in the perisomatic region of the frontal cortical pyramidal neuron and its striatal terminals, respectively. We also review the evidence to support the DR as a therapeutic target for ADHD and other impulse-control disorders, as well as for restless legs syndrome.
Topics: Humans; Receptors, Dopamine D4; Dopamine; Norepinephrine; Adrenergic Agents; Amino Acids; Proline
PubMed: 36267569
DOI: 10.3389/fendo.2022.1014678