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Journal of Experimental & Clinical... Jan 2024Extensive local invasion of glioblastoma (GBM) cells within the central nervous system (CNS) is one factor that severely limits current treatments. The aim of this study...
BACKGROUND
Extensive local invasion of glioblastoma (GBM) cells within the central nervous system (CNS) is one factor that severely limits current treatments. The aim of this study was to uncover genes involved in the invasion process, which could also serve as therapeutic targets. For the isolation of invasive GBM cells from non-invasive cells, we used a three-dimensional organotypic co-culture system where glioma stem cell (GSC) spheres were confronted with brain organoids (BOs). Using ultra-low input RNA sequencing (ui-RNA Seq), an invasive gene signature was obtained that was exploited in a therapeutic context.
METHODS
GFP-labeled tumor cells were sorted from invasive and non-invasive regions within co-cultures. Ui-RNA sequencing analysis was performed to find a gene cluster up-regulated in the invasive compartment. This gene cluster was further analyzed using the Connectivity MAP (CMap) database. This led to the identification of SKF83566, an antagonist of the D1 dopamine receptor (DRD1), as a candidate therapeutic molecule. Knockdown and overexpression experiments were performed to find molecular pathways responsible for the therapeutic effects of SKF83566. Finally, the effects of SKF83566 were validated in orthotopic xenograft models in vivo.
RESULTS
Ui-RNA seq analysis of three GSC cell models (P3, BG5 and BG7) yielded a set of 27 differentially expressed genes between invasive and non-invasive cells. Using CMap analysis, SKF83566 was identified as a selective inhibitor targeting both DRD1 and DRD5. In vitro studies demonstrated that SKF83566 inhibited tumor cell proliferation, GSC sphere formation, and invasion. RNA sequencing analysis of SKF83566-treated P3, BG5, BG7, and control cell populations yielded a total of 32 differentially expressed genes, that were predicted to be regulated by c-Myc. Of these, the UHRF1 gene emerged as the most downregulated gene following treatment, and ChIP experiments revealed that c-Myc binds to its promoter region. Finally, SKF83566, or stable DRD1 knockdown, inhibited the growth of orthotopic GSC (BG5) derived xenografts in nude mice.
CONCLUSIONS
DRD1 contributes to GBM invasion and progression by regulating c-Myc entry into the nucleus that affects the transcription of the UHRF1 gene. SKF83566 inhibits the transmembrane protein DRD1, and as such represents a candidate small therapeutic molecule for GBMs.
Topics: Animals; Humans; Mice; Brain; CCAAT-Enhancer-Binding Proteins; Dopamine; Glioblastoma; Glioma; Mice, Nude; Multigene Family; Receptors, Dopamine D1; Ubiquitin-Protein Ligases; Dopamine Antagonists; Proto-Oncogene Proteins c-myc
PubMed: 38246990
DOI: 10.1186/s13046-024-02947-7 -
ELife Oct 2020The observation of animal orofacial and behavioral reactions has played a fundamental role in research on reward but is seldom assessed in humans. Healthy volunteers (N...
The observation of animal orofacial and behavioral reactions has played a fundamental role in research on reward but is seldom assessed in humans. Healthy volunteers (N = 131) received 400 mg of the dopaminergic antagonist amisulpride, 50 mg of the opioidergic antagonist naltrexone, or placebo. Subjective ratings, physical effort, and facial reactions to matched primary social (affective touch) and nonsocial (food) rewards were assessed. Both drugs resulted in lower physical effort and greater negative facial reactions during reward anticipation, especially of food rewards. Only opioidergic manipulation through naltrexone led to a reduction in positive facial reactions to liked rewards during reward consumption. Subjective ratings of wanting and liking were not modulated by either drug. Results suggest that facial reactions during anticipated and experienced pleasure rely on partly different neurochemical systems, and also that the neurochemical bases for food and touch rewards are not identical.
Topics: Adult; Amisulpride; Dopamine Antagonists; Emotions; Female; Food; Humans; Male; Naltrexone; Narcotic Antagonists; Pleasure; Reward; Young Adult
PubMed: 33046213
DOI: 10.7554/eLife.55797 -
Pharmacology, Biochemistry, and Behavior Nov 2020Considerable evidence indicates that adenosine and dopamine systems interact in the regulation of basal ganglia function. Nonselective adenosine antagonists such as the...
Considerable evidence indicates that adenosine and dopamine systems interact in the regulation of basal ganglia function. Nonselective adenosine antagonists such as the methylxanthine caffeine as well as selective adenosine A antagonists have been shown to produce antiparkinsonian and antidepressant effects in animal models. The present studies were conducted to assess if another methylxantine, theophylline, can reverse motor and motivational impairments induced by dopamine antagonism in rats. RESULTS: Theophylline (3.75-30.0 mg/kg, IP) reversed tremulous jaw movements (TJMs), catalepsy, and locomotor suppression induced by the dopamine D2 antagonist pimozide. It also reversed TJMs induced by the muscarinic receptor agonist pilocarpine, which is a well-known tremorogenic agent. Parallel studies assessed the ability of theophylline (5.0-20.0 mg/kg, IP) to reverse the changes in effort-related choice behavior induced by the dopamine D1 antagonist ecopipam (0.2 mg/kg, IP) and the D2 antagonist haloperidol (0.1 mg/kg, IP). Rats were tested on two different operant choice tasks which assess the tendency to work for a preferred reinforcer by lever pressing (for palatable pellets or a high 5% sucrose solution) vs. approaching and consuming a less preferred reinforcer (freely available lab chow or a less concentrated 0.3% sucrose solution). Theophylline restored food and sucrose-reinforced lever pressing in animals treated with the D2 antagonist. However, it was unable to reverse the effects of the D1 antagonist. Overall, the effects of theophylline resembled those previously reported for adenosine A antagonists, and suggest that theophylline could be clinically useful for the treatment of motor and motivational symptoms in humans.
Topics: Animals; Behavior, Animal; Benzazepines; Catalepsy; Choice Behavior; Conditioning, Operant; Dopamine Antagonists; Haloperidol; Humans; Male; Motivation; Motor Activity; Muscarinic Agonists; Pilocarpine; Pimozide; Purinergic P1 Receptor Antagonists; Rats; Rats, Sprague-Dawley; Sucrose; Theophylline; Tremor
PubMed: 32910928
DOI: 10.1016/j.pbb.2020.173035 -
The European Journal of Neuroscience Jan 2024Separable striatal circuits have unique functions in Pavlovian and instrumental behaviors but how these roles relate to performance of sequences of actions with and...
Separable striatal circuits have unique functions in Pavlovian and instrumental behaviors but how these roles relate to performance of sequences of actions with and without associated cues are less clear. Here, we tested whether dopamine transmission and neural activity more generally in three striatal subdomains are necessary for performance of an action chain leading to reward delivery. Male and female Long-Evans rats were trained to press a series of three spatially distinct levers to receive reward. We assessed the contribution of neural activity or dopamine transmission within each striatal subdomain when progression through the action sequence was explicitly cued and in the absence of cues. Behavior in both task variations was substantially impacted following microinfusion of the dopamine antagonist, flupenthixol, into nucleus accumbens core (NAc) or dorsomedial striatum (DMS), with impairments in sequence timing and numbers of rewards earned after NAc flupenthixol. In contrast, after pharmacological inactivation to suppress overall activity, there was minimal impact on total rewards earned. Instead, inactivation of both NAc and DMS impaired sequence timing and led to sequence errors in the uncued, but not cued task. There was no impact of dopamine antagonism or reversible inactivation of dorsolateral striatum on either cued or uncued action sequence completion. These results highlight an essential contribution of NAc and DMS dopamine systems in motivational and performance aspects of chains of actions, whether cued or internally generated, as well as the impact of intact NAc and DMS function for correct sequence performance.
Topics: Female; Rats; Animals; Male; Rats, Long-Evans; Nucleus Accumbens; Dopamine; Flupenthixol; Motivation; Cues; Dopamine Antagonists; Reward; Conditioning, Operant
PubMed: 38093522
DOI: 10.1111/ejn.16210 -
Behavioural Brain Research Aug 2023The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed...
The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.
Topics: Animals; Male; Mice; Apomorphine; Benzazepines; Dopamine; Dopamine Antagonists; Receptors, Dopamine D1; Sulpiride
PubMed: 37394124
DOI: 10.1016/j.bbr.2023.114562 -
Journal of Neurophysiology Jul 2022Abnormalities of auditory steady-state responses (ASSRs) and the effects of antipsychotic drugs on ASSRs have been investigated in patients with schizophrenia. It is...
Abnormalities of auditory steady-state responses (ASSRs) and the effects of antipsychotic drugs on ASSRs have been investigated in patients with schizophrenia. It is presumed that drugs do not directly affect ASSRs because its abnormalities are associated with schizophrenia. Therefore, to investigate the direct effect of drugs on ASSRs, we established an ASSR evaluation system for common marmosets in a naïve state. Dopamine D1 receptor stimulation (SKF-81297, 2 mg/kg ip) significantly increased evoked power (EP) at 40 Hz. The phase locking factor (PLF) was increased significantly at 20, 30, 40, and 80 Hz. However, administration of a dopamine D1 receptor antagonist (SCH-39166, 0.3 mg/kg ip) resulted in a significant decrease in EP and PLF at 30 Hz. Dopamine D2 receptor stimulation (quinpirole, 1 mg/kg im) tended to increase EP and induced power (IP) at all frequencies, and a significant difference was observed at 30 Hz IP. There was no change in PLF at all frequencies. In addition, dopamine D2 receptor blockade (raclopride, 3 mg/kg ip) reduced EP and PLF at 30 Hz. Subcutaneous administration of the serotonin dopamine antagonist, risperidone (0.3 mg/kg), tended to increase IP and decrease PLF, but not significantly. Taken together, it is possible to compare the differences in the mode of action of drugs on ASSRs using naïve nonhuman primates. We measured the effects of dopamine receptor-related compounds on ASSR in marmosets. D1 receptor stimulation increased the phase locking factor (PLF) and evoked power (EP), and reduced the induced power (IP). D2 receptor stimulation increased the IP. D1 and D2 receptor blockers reduced the PLF and EP at 30 Hz. Different modes of action of various drugs related to psychiatric disorders were evaluated by administering antipsychotic drugs to naïve marmosets.
Topics: Acoustic Stimulation; Animals; Antipsychotic Agents; Callithrix; Dopamine Antagonists; Evoked Potentials, Auditory; Humans; Receptors, Dopamine D1; Receptors, Dopamine D2
PubMed: 35583977
DOI: 10.1152/jn.00147.2022 -
European Journal of Pharmacology May 2022In this study, a pharmacological approach, together with the paw pressure test, was used to investigate the role of dopamine and its receptors in the peripheral...
In this study, a pharmacological approach, together with the paw pressure test, was used to investigate the role of dopamine and its receptors in the peripheral processing of the nociceptive response in mice. Initially, the administration of dopamine (5, 20, and 80 ng/paw) in the hind paw of male Swiss mice (30-40 g) promoted antinociceptive effects in a dose-dependent manner. This was considered a peripheral effect, as it did not produce changes in the nociceptive threshold of the contralateral paw. The D, D, and D dopamine receptor antagonists remoxipride (4 μg/paw), U99194 (16 μg/paw), and L-745,870 (16 μg/paw), respectively, reversed the dopamine-mediated antinociception in mice with PGE-induced hyperalgesia. The D and D dopamine receptor antagonists SKF 83566 (2 μg/paw) and SCH 23390 (1.6 μg/paw), respectively, did not alter dopamine antinociception. In contrast, dopamine at higher doses (0.1, 1, and 10 μg/paw) caused hyperalgesia in the animals, and the D and D receptor antagonists reversed this pronociceptive effect (10 μg/paw), whereas the D receptor antagonist remoxipride did not. Our data suggest that dopamine has a dual effect that depends on the dose, as it causes peripheral antinociceptive effects at small doses via the activation of D-like receptors and nociceptive effects at higher doses via the activation of D-like receptors.
Topics: Analgesia; Analgesics; Animals; Dopamine; Dopamine Antagonists; Hyperalgesia; Male; Mice; Nociception; Pain; Receptors, Dopamine D1; Remoxipride
PubMed: 35300994
DOI: 10.1016/j.ejphar.2022.174872 -
Behavioural Pharmacology Jun 2022Lorcaserin is a modestly selective agonist for 2C serotonin receptors (5-HT2CR). Despite early promising data, it recently failed to facilitate cocaine abstinence in... (Review)
Review
Lorcaserin is a modestly selective agonist for 2C serotonin receptors (5-HT2CR). Despite early promising data, it recently failed to facilitate cocaine abstinence in patients and has been compared with dopamine antagonist medications (antipsychotics). Here, we review the effects of both classes on drug reinforcement. In addition to not being effective treatments for cocaine use disorder, both dopamine antagonists and lorcaserin can have biphasic effects on dopamine and reward behavior. Lower doses can cause enhanced drug taking with higher doses causing reductions. This biphasic pattern is shared with certain stimulants, opioids, and sedative-hypnotics, as well as compounds without abuse potential that include agonists for muscarinic and melatonin receptors. Additional factors associated with decreased drug taking include intermittent dosing for dopamine antagonists and use of progressive-ratio schedules for lorcaserin. Clinically relevant doses of lorcaserin were much lower than those that inhibited cocaine-reinforced behavior and can also augment this same behavior in different species. Diminished drug-reinforced behavior only occurred in animals after higher doses that are not suitable for use in patients. In conclusion, drugs of abuse and related compounds often act as biphasic modifiers of reward behavior, especially when evaluated over a broad range of doses. This property may reflect the underlying physiology of the reward system, allowing homeostatic influences on behavior.
Topics: Animals; Benzazepines; Cocaine; Cocaine-Related Disorders; Dopamine; Dopamine Antagonists; Dose-Response Relationship, Drug; Humans; Reward; Self Administration; Substance-Related Disorders
PubMed: 35324488
DOI: 10.1097/FBP.0000000000000672 -
Psychopharmacology Mar 2015(-)-Stepholidine is a tetrahydroberberine alkaloid that is known to interact with dopamine receptors and has also been proposed as a novel antipsychotic agent. Its...
RATIONALE
(-)-Stepholidine is a tetrahydroberberine alkaloid that is known to interact with dopamine receptors and has also been proposed as a novel antipsychotic agent. Its suggested novelty lies in the fact that it has been proposed to have D1-like receptor agonist and D2-like receptor antagonist properties. Thus, it might be effective in treating both positive and negative (cognition) symptoms of schizophrenia. However, its activity on specific dopamine receptor subtypes has not been clarified, especially with respect to its ability to activate D1-like receptors.
OBJECTIVES
We wished to examine the affinity and functional activity of (-)-stepholidine at each of the human dopamine receptor subtypes expressed in a defined cellular environment.
METHODS
D1-D5 dopamine receptors were stably expressed in cell lines and their interactions with (-)-stepholidine were examined using radioligand binding and various functional signaling assays. Radioligand binding assays were also performed using bovine striatal membranes.
RESULTS
(-)-Stepholidine exhibited high (nM) affinity for D1 and D5 receptors, somewhat lower (two- to four-fold) affinity for D2 and D3 receptors, and low micromolar affinity for D4 receptors. Functionally, (-)-stepholidine was ineffective in activating G protein-mediated signaling of D1-like and D2 receptors and was also ineffective in stimulating β-arrestin recruitment to any dopamine receptor subtype. It did, however, antagonize all of these responses. It also antagonized D1-D2 heteromer-mediated Ca(2+) mobilization. Radioligand binding assays of D1-like receptors in brain membranes also indicated that (-)-stepholidine binds to the D1 receptor with antagonist-like properties.
CONCLUSIONS
(-)-Stepholidine is a pan-dopamine receptor antagonist and its in vivo effects are largely mediated through dopamine receptor blockade with potential cross-talk to other receptors or signaling proteins.
Topics: Animals; Arrestins; Berberine; Brain; CHO Cells; Cricetulus; Dopamine Antagonists; GTP-Binding Proteins; HEK293 Cells; Humans; Receptors, Dopamine; Receptors, Dopamine D5; Signal Transduction; beta-Arrestins
PubMed: 25231919
DOI: 10.1007/s00213-014-3726-8 -
Psychopharmacology Sep 2022Learning the association between rewards and predictive cues is critical for appetitive behavioral responding. The mesolimbic dopamine system is thought to play an...
RATIONALE
Learning the association between rewards and predictive cues is critical for appetitive behavioral responding. The mesolimbic dopamine system is thought to play an integral role in establishing these cue-reward associations. The dopamine response to cues can signal differences in reward value, though this emerges only after significant training. This suggests that the dopamine system may differentially regulate behavioral responding depending on the phase of training.
OBJECTIVES
The purpose of this study was to determine whether antagonizing dopamine receptors elicited different effects on behavior depending on the phase of training or the type of Pavlovian task.
METHODS
Separate groups of male rats were trained on Pavlovian tasks in which distinct audio cues signaled either differences in reward size or differences in reward rate. The dopamine receptor antagonist flupenthixol was systemically administered prior to either the first ten sessions of training (acquisition phase) or the second ten sessions of training (expression phase), and we monitored the effect of these manipulations for an additional ten training sessions.
RESULTS
We identified acute effects of dopamine receptor antagonism on conditioned responding, the latency to respond, and post-reward head entries in both Pavlovian tasks. Interestingly, dopamine receptor antagonism during the expression phase produced persistent deficits in behavioral responding only in rats trained on the reward size Pavlovian task.
CONCLUSIONS
Together, our results illustrate that dopamine's control over behavior in Pavlovian tasks depends upon one's prior training experience and the information signaled by the cues.
Topics: Animals; Conditioning, Classical; Conditioning, Operant; Cues; Dopamine; Dopamine Antagonists; Male; Rats; Rats, Sprague-Dawley; Receptors, Dopamine; Reward
PubMed: 35796814
DOI: 10.1007/s00213-022-06182-w