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Cellular Signalling Jan 2018Compounds that target D2-like dopamine receptors (DRs) are currently used as therapeutics for several neuropsychiatric disorders including schizophrenia (antagonists)... (Review)
Review
Compounds that target D2-like dopamine receptors (DRs) are currently used as therapeutics for several neuropsychiatric disorders including schizophrenia (antagonists) and Parkinson's disease (agonists). However, as the DR and DR subtypes are highly homologous, creating compounds with sufficient subtype-selectivity as well as drug-like properties for therapeutic use has proved challenging. This review summarizes the progress that has been made in developing DR- or DR-selective antagonists and agonists, and also describes the experimental conditions that need to be considered when determining the selectivity of a given compound, as apparent selectivity can vary widely depending on assay conditions. Future advances in this field may take advantage of currently available structural data to target alternative secondary binding sites through creating bivalent or bitopic chemical structures. Alternatively, the use of high-throughput screening techniques to identify novel scaffolds that might bind to the DR or DR in areas other than the highly conserved orthosteric site, such as allosteric sites, followed by iterative medicinal chemistry will likely lead to exceptionally selective compounds in the future. More selective compounds will provide a better understanding of the normal and pathological functioning of each receptor subtype, as well as offer the potential for improved therapeutics.
Topics: Allosteric Site; Animals; Antiparkinson Agents; Binding Sites; Dopamine Agonists; Drug Design; Humans; Molecular Structure; Parkinson Disease; Receptors, Dopamine D2; Receptors, Dopamine D3; Schizophrenia; Structure-Activity Relationship
PubMed: 28716664
DOI: 10.1016/j.cellsig.2017.07.003 -
Amino Acids Jun 2017Dopamine receptors 1 and 2 (DRD1, DRD2) are essential for signaling in the brain for a multitude of brain functions. Previous work using several antibodies against these...
Dopamine receptors 1 and 2 (DRD1, DRD2) are essential for signaling in the brain for a multitude of brain functions. Previous work using several antibodies against these receptors is abundant but only the minority of antibodies used have been validated and, therefore, the results of these studies remain uncertain. Herein, antibodies against DRD1 (Merck Millipore AB1765P, Santa Cruz Biotechnology sc-14001, Sigma Aldrich D2944, Alomone Labs ADR-001) and DRD2 (Abcam ab21218, Merck Millipore AB5084P, Santa Cruz Biotechnology sc-5303) have been tested using western blotting and immunohistochemistry on mouse striatum (wild type and corresponding knock-out mice) and when specific, they were further evaluated on rat and human striatum. Moreover, a DRD1 antibody and a DRD2 antibody that were found specific in our tests were used for immunoprecipitation with subsequent mass spectrometrical identification of the immunoprecipitate. Two out of nine antibodies (anti DRD1 Sigma Aldrich D2944 and anti DRD2 Merck Millipore AB5084P) against the abovementioned dopamine receptors were specific for DRD1 and DRD2 as evaluated by western blotting and immunohistochemistry and the immunoprecipitate indeed contained DRD1 and DRD2 as revealed by mass spectrometry. The observed findings may question the use of so far non-validated antibodies against the abovementioned dopamine receptors. Own observations may be valuable for the interpretation of previous results and the design of future studies using dopamine receptors DRD1 or DRD2.
Topics: Animals; Antibodies; Antibody Specificity; Corpus Striatum; Mice; Mice, Knockout; Receptors, Dopamine D1; Receptors, Dopamine D2
PubMed: 28316027
DOI: 10.1007/s00726-017-2408-3 -
Medical Hypotheses Oct 2020Prepulse inhibition (PPI) of acoustic startle reflex is a measure of sensorimotor gating that may reflect the biological processes underlying gaiting impairments in...
Prepulse inhibition (PPI) of acoustic startle reflex is a measure of sensorimotor gating that may reflect the biological processes underlying gaiting impairments in schizophrenia. Although PPI is clinically useful, why PPI is inhibited in schizophrenia is largely unknown. Prepulse inhibition is mediated by M2-like muscarinic acetylcholine receptor on neurons in the caudal pontine reticular nucleus (PnC), activation of this receptor induces Gαi dissociation, and inhibits adenylyl cyclase, resulting in the inhibition of the neurons. On the other hand, the symptoms of schizophrenia are mainly linked to hyperactive dopaminergic activity, mediated by dopamine D2-like receptor. Interestingly, D2-like receptor also uses Gαi. This means that both M2-like acetylcholine receptor and D2-like dopamine receptor use same Gαi-protein, competitively. Thus, chronic over-activation of D2-like receptor observed in schizophrenia may disrupt normal M2-like acetylcholine receptor functions due to their shared coupling to Gαi-proteins, i.e. by reducing the amount of Gαi-protein available for M2-like acetylcholine receptors, resulting in the impairment of PPI.
Topics: Acoustic Stimulation; Humans; Prepulse Inhibition; Receptors, Dopamine; Reflex, Startle; Schizophrenia
PubMed: 32502900
DOI: 10.1016/j.mehy.2020.109901 -
Anti-cancer Agents in Medicinal... 2021Dopamine Receptor (DR) gene family play an essential role in the regulation of Interleukin- 6 (IL-6) production. Our prior analysis of human prostate biopsy samples...
BACKGROUND
Dopamine Receptor (DR) gene family play an essential role in the regulation of Interleukin- 6 (IL-6) production. Our prior analysis of human prostate biopsy samples demonstrated the increased expression of IL-6 and a downregulating trend for dopamine receptor gene family.
OBJECTIVE
The objective was to investigate the expression of dopamine receptors, their catabolizing enzyme and IL-6 in prostate cancer cell lines and assess pharmacological effect of dopamine receptor modulators as a novel class of drugs repurposed for the treatment of prostate cancer.
METHODS
The therapeutic effect of dopamine, DR agonists, and DR antagonist were examined using LNCaP and PC3 cell lines. Cell viability and proliferation were assessed by MTT assay and proliferating cell nuclear antigen expression analysis, respectively. Furthermore, bax/bcl2 ratio, immunofluorescence assay and flow cytometric assay were performed for apoptosis analysis. RT- qPCR analysis was used to characterize the relative expression of dopamine-related genes, catabolic enzyme Catechol-o-Methyl-Transferase (COMT) and IL-6 before and after treatment to assess the therapeutic effects of drugs.
RESULTS
LNCaP cells express DRD1, DRD2, DRD5 and COMT genes and PC3 cells only express IL-6 gene. In-vitro, dopamine receptor agonists reduced cell viability of LNCaP and PC3 cells. In contrast, dopamine and dopamine receptor antagonist significantly increased tumor growth in PC3 cells.
CONCLUSION
Our results offer novel suggestion for a pathogenic role of dopamine receptor signaling in prostate cancer adenocarcinoma and indicates that modulators of DR- IL-6 pathway, including FDA-approved drug bromocriptine, might be utilized as novel drug repurposing strategy.
Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Male; Molecular Structure; Prostatic Neoplasms; Receptors, Dopamine; Structure-Activity Relationship
PubMed: 32867661
DOI: 10.2174/1871520620999200831110243 -
Technology in Cancer Research &... 2021The dopamine receptors (DRs) family includes 5 members with differences in signal transduction and ligand affinity. Abnormal DRs expression has been correlated multiple... (Review)
Review
The dopamine receptors (DRs) family includes 5 members with differences in signal transduction and ligand affinity. Abnormal DRs expression has been correlated multiple tumors with their clinical outcome. Thus, it has been proposed that DRs-targeting drugs-developed for other diseases as schizophrenia or Parkinson's disease-could be helpful in managing neoplastic diseases. In this review, we discuss the role of DRs and the effects of DRs-targeting in tumor progression and cancer cell biology using multiple high-prevalence neoplasms as examples. The evidence shows that DRs are valid therapeutic targets for certain receptor/disease combinations, but the data are inconclusive or contradictory for others. In either case, further studies are required to define the precise role of DRs in tumor progression and propose better therapeutic strategies for their targeting.
Topics: Animals; Dopamine Agonists; Dopamine Antagonists; Humans; Molecular Targeted Therapy; Neoplasms; Receptors, Dopamine; Signal Transduction
PubMed: 34212819
DOI: 10.1177/15330338211027913 -
ACS Chemical Neuroscience Mar 2020Kinetic analysis of dopamine receptor activation and inactivation and the study of dopamine-dependent signaling requires precise simulation of the presynaptic release of...
Kinetic analysis of dopamine receptor activation and inactivation and the study of dopamine-dependent signaling requires precise simulation of the presynaptic release of the neurotransmitter dopamine and tight temporal control over the release of dopamine receptor antagonists. The 8-cyano-7-hydroxyquinolinyl (CyHQ) photoremovable protecting group was conjugated to dopamine and the dopamine receptor antagonist sulpiride to generate "caged" versions of these neuromodulators (CyHQ--DA and CyHQ-sulpiride, respectively) that could release their payloads with 365 or 405 nm light or through 2-photon excitation (2PE) at 740 nm. These compounds are stable under physiological conditions in the dark, yet photolyze rapidly and cleanly to yield dopamine or sulpiride and the caging remnant CyHQ-OH. CyHQ--DA mediated the light activation of dopamine-1 (D1) receptors on the breast cancer cell line MDA-MB-231 in culture. In mouse brain slice from the substantia nigra pars compacta, localized flash photolysis of CyHQ--DA accurately mimicked the natural presynaptic release of dopamine and activation of dopamine-2 (D2) receptors, causing a robust, concentration-dependent, and repeatable G protein-coupled inwardly rectifying potassium channel-mediated outward current in whole-cell voltage clamp recordings that was amplified by cocaine and blocked by sulpiride. Photolysis of CyHQ-sulpiride rapidly blocked synaptic activity, enabling measurement of the unbinding rates of dopamine and quinpirole, a D2 receptor agonist. These tools will enable more detailed study of dopamine receptors, their interactions with other GPCRs, and the physiology of dopamine signaling in the brain.
Topics: Animals; Dopamine; Dopamine Agonists; Dopaminergic Neurons; Kinetics; Mice; Quinpirole; Receptors, Dopamine D1; Sulpiride
PubMed: 32077679
DOI: 10.1021/acschemneuro.9b00675 -
Drugs Oct 2019Bipolar disorder is a chronic, disabling, and costly illness with frequent relapses and recurrences, high rates of co-morbid conditions, and poor adherence to treatment.... (Review)
Review
Bipolar disorder is a chronic, disabling, and costly illness with frequent relapses and recurrences, high rates of co-morbid conditions, and poor adherence to treatment. Mood stabilizers and antipsychotics are the cornerstones of treatment. Dopamine receptor partial agonists are a novel class of antipsychotic agents with original pharmacodynamic properties. Among them, two have been approved by the US Food and Drug Administration for the treatment of bipolar disorder. Aripiprazole (oral formulation) has been approved as monotherapy for the treatment of manic/mixed episodes in adult and pediatric populations and for maintenance treatment in adults, and as adjunctive treatment to mood stabilizers, for the acute treatment of manic/mixed episodes and for maintenance in adults. An intramuscular formulation of aripiprazole has been approved for the treatment of agitation in mania and a long-acting injectable formulation has been approved as maintenance treatment. In the USA, cariprazine has been approved as monotherapy for the acute treatment of manic/mixed as well as bipolar depressive episodes. Brexpiprazole is not yet approved to treat bipolar disorder. The evidence supporting these indications is reviewed via an analysis of clinical registration trials as well as additional studies, on the basis of a systematic literature search. Further studies dealing with other aspects of bipolar illness are also presented. Aripiprazole and cariprazine are efficacious and generally well tolerated agents that have shown cost effectiveness, and may therefore enrich our therapeutic armamentarium for bipolar illness. Brexpiprazole, which displays an overall promising tolerability profile, deserves further efficacy studies.
Topics: Antipsychotic Agents; Aripiprazole; Bipolar Disorder; Dopamine Agonists; Humans; Piperazines; Receptors, Dopamine; United States; United States Food and Drug Administration
PubMed: 31468317
DOI: 10.1007/s40265-019-01189-8 -
Naunyn-Schmiedeberg's Archives of... Jan 2020Repeated administration of stimulants induces conditioned place preference (CPP). Dopamine receptor supersensitivity is developed in stimulant-induced CPP animals;...
Repeated administration of stimulants induces conditioned place preference (CPP). Dopamine receptor supersensitivity is developed in stimulant-induced CPP animals; however, dopamine receptor subtypes associated with the development of supersensitivity in CPP animals are largely unknown. The present preclinical study aimed to examine whether dopamine D1 or D2 receptor antagonists exert inhibitory effects on stimulant-induced psychological behaviors. Additionally, the authors aimed to elucidate the role of dopamine receptor supersensitivity on the development of reward-related behavior. Sprague Dawley rats subjected to methamphetamine- and cocaine-induced CPP tests were treated with dopamine D1 (SCH23390) or D2 (sulpiride) receptor antagonists. Following the CPP experiment, rats were challenged with apomorphine (dopamine receptor agonist), and locomotor activity was measured. Methamphetamine- and cocaine-induced CPP was reduced with the administration of SCH23390, but not sulpiride. In addition, the apomorphine challenge evoked an increase in locomotor activity in stimulant-pre-treated rats, reflecting dopamine receptor supersensitivity. SCH23390 pre-treatment inhibited the development of dopamine receptor supersensitivity, while sulpiride demonstrated no inhibitory effects. These results suggest that the dopamine D1 receptor antagonist SCH23390 inhibits the development of dopamine receptor supersensitivity which is associated with the development of CPP.
Topics: Animals; Benzazepines; Central Nervous System Stimulants; Cocaine; Conditioning, Psychological; Dopamine Antagonists; Locomotion; Male; Methamphetamine; Rats; Rats, Sprague-Dawley; Receptors, Dopamine D1; Receptors, Dopamine D2; Sulpiride
PubMed: 31372696
DOI: 10.1007/s00210-019-01694-3 -
Clinical Cancer Research : An Official... Apr 2019Dopamine receptor D2 (DRD2) is a G protein-coupled receptor antagonized by ONC201, an anticancer small molecule in clinical trials for high-grade gliomas and other...
PURPOSE
Dopamine receptor D2 (DRD2) is a G protein-coupled receptor antagonized by ONC201, an anticancer small molecule in clinical trials for high-grade gliomas and other malignancies. DRD5 is a dopamine receptor family member that opposes DRD2 signaling. We investigated the expression of these dopamine receptors in cancer and their influence on tumor cell sensitivity to ONC201.
EXPERIMENTAL DESIGN
The Cancer Genome Atlas was used to determine DRD2/DRD5 expression broadly across human cancers. Cell viability assays were performed with ONC201 in >1,000 Genomic of Drug Sensitivity in Cancer and NCI60 cell lines. IHC staining of DRD2/DRD5 was performed on tissue microarrays and archival tumor tissues of glioblastoma patients treated with ONC201. Whole exome sequencing was performed in RKO cells with and without acquired ONC201 resistance. Wild-type and mutant DRD5 constructs were generated for overexpression studies.
RESULTS
DRD2 overexpression broadly occurs across tumor types and is associated with a poor prognosis. Whole exome sequencing of cancer cells with acquired resistance to ONC201 revealed a Q366R mutation in the DRD5 gene. Expression of Q366R DRD5 was sufficient to induce tumor cell apoptosis, consistent with a gain-of-function. DRD5 overexpression in glioblastoma cells enhanced DRD2/DRD5 heterodimers and DRD5 expression was inversely correlated with innate tumor cell sensitivity to ONC201. Investigation of archival tumor samples from patients with recurrent glioblastoma treated with ONC201 revealed that low DRD5 expression was associated with relatively superior clinical outcomes.
CONCLUSIONS
These results implicate DRD5 as a negative regulator of DRD2 signaling and tumor sensitivity to ONC201 DRD2 antagonism.
Topics: Antineoplastic Agents; Biomarkers; Cell Line, Tumor; Cell Survival; Dopamine D2 Receptor Antagonists; Drug Resistance; Gene Expression; Humans; Imidazoles; Immunohistochemistry; Magnetic Resonance Imaging; Neoplasm Grading; Neoplasm Staging; Neoplasms; Prognosis; Protein Binding; Pyridines; Pyrimidines; Receptors, Dopamine D2; Receptors, Dopamine D5; Signal Transduction
PubMed: 30559168
DOI: 10.1158/1078-0432.CCR-18-2572 -
Scientific Reports Jun 2023The striatum integrates dense neuromodulatory inputs from many brain regions to coordinate complex behaviors. This integration relies on the coordinated responses from...
The striatum integrates dense neuromodulatory inputs from many brain regions to coordinate complex behaviors. This integration relies on the coordinated responses from distinct striatal cell types. While previous studies have characterized the cellular and molecular composition of the striatum using single-cell RNA-sequencing at distinct developmental timepoints, the molecular changes spanning embryonic through postnatal development at the single-cell level have not been examined. Here, we combine published mouse striatal single-cell datasets from both embryonic and postnatal timepoints to analyze the developmental trajectory patterns and transcription factor regulatory networks within striatal cell types. Using this integrated dataset, we found that dopamine receptor-1 expressing spiny projection neurons have an extended period of transcriptional dynamics and greater transcriptional complexity over postnatal development compared to dopamine receptor-2 expressing neurons. Moreover, we found the transcription factor, FOXP1, exerts indirect changes to oligodendrocytes. These data can be accessed and further analyzed through an interactive website ( https://mouse-striatal-dev.cells.ucsc.edu ).
Topics: Animals; Mice; Neurons; Corpus Striatum; Neostriatum; Transcription Factors; Receptors, Dopamine
PubMed: 37270616
DOI: 10.1038/s41598-023-36255-5