cariprazine and Disease-Models--Animal

Partial agonist activity at the dopamine D

Topics: Animals; Cell Line, Tumor; Disease Models, Animal; Dopamine Agonists; Drug Design; Drug Evaluation, Preclinical; Half-Life; Humans; Mice; Mice, Inbred ICR; Receptors, Dopamine D2; Stereoisomerism; Structure-Activity Relationship

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Aberrant glutamatergic, dopaminergic, and GABAergic neurotransmission has been implicated in schizophrenia. Cariprazine reverses the behavioral effects observed in the rat phencyclidine (PCP)-induced model of schizophrenia; however, little is known about its in vivo neurochemistry.. The study aims to compare the effects of cariprazine and aripiprazole on PCP-induced changes in the extracellular levels of glutamate, dopamine, serotonin, noradrenaline, and GABA in the rat medial prefrontal cortex (mPFC), and on locomotor activation.. Microdialysis was performed in awake rats with probes placed into the mPFC. Rats (n = 7/group) received vehicle (saline), cariprazine (0.05, 0.2, or 0.8 mg/kg), or aripiprazole (3 or 20 mg/kg) via gavage. After 60 min, 5 mg/kg PCP was administered intraperitoneally (i.p.). Samples were taken before drug administration, during pretreatment, and after PCP injection. Locomotor activity recording and microdialysis sampling occurred simultaneously.. PCP treatment increased extracellular levels of all the neurotransmitters tested except GABA, for which there were no significant changes. Cariprazine and aripiprazole dose-dependently inhibited the PCP-induced increases of tested neurotransmitters. Overall effects were significant for higher cariprazine doses and both aripiprazole doses for glutamate and noradrenaline, for higher cariprazine doses and 20 mg/kg aripiprazole for dopamine, and for 0.8 mg/kg cariprazine and 20 mg/kg aripiprazole for serotonin and locomotor activity.. Both cariprazine and aripiprazole dose-dependently attenuated PCP-induced hyperlocomotion and acute increases in glutamate, dopamine, noradrenaline, and serotonin levels in the mPFC; cariprazine was approximately 5-fold more potent than aripiprazole.

Topics: Animals; Antipsychotic Agents; Disease Models, Animal; Dopamine; Dose-Response Relationship, Drug; Extracellular Fluid; gamma-Aminobutyric Acid; Glutamic Acid; Locomotion; Male; Microdialysis; Norepinephrine; Phencyclidine; Piperazines; Prefrontal Cortex; Rats; Rats, Sprague-Dawley; Schizophrenia; Serotonin

Dopamine D

Topics: Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Ligands; Mice; Molecular Structure; Positron-Emission Tomography; Pyrazoles; Pyridines; Rats; Receptors, Dopamine D3; Structure-Activity Relationship

Cariprazine, a D3-preferring dopamine D2/D3 receptor partial agonist, is a new antipsychotic drug recently approved in the United States for the treatment of schizophrenia and bipolar mania. We recently demonstrated that cariprazine also has significant antianhedonic-like effects in rats subjected to chronic stress; however, the exact mechanism of action for cariprazine's antidepressant-like properties is not known. Thus, in this study we examined whether the effects of cariprazine are mediated by dopamine D3 receptors.. Wild-type and D3-knockout mice were exposed to chronic unpredictable stress for up to 26 days, treated daily with vehicle, imipramine (20 mg/kg), aripiprazole (1 and 5 mg/kg), or cariprazine (0.03, 0.1, 0.2, and 0.4 mg/kg), and tested in behavioral assays measuring anhedonia and anxiety-like behaviors.. Results showed that cariprazine significantly attenuated chronic unpredictable stress-induced anhedonic-like behavior in wild-type mice, demonstrating potent antidepressant-like effects comparable with aripiprazole and the tricyclic antidepressant imipramine. This antianhedonic-like effect of cariprazine was not observed in D3-knockout mice, suggesting that the cariprazine antidepressant-like activity is mediated by dopamine D3 receptors. Moreover, cariprazine significantly reduced drinking latency in the novelty-induced hypophagia test in wild-type mice, further confirming its antianhedonic-like effect and showing that it also has anxiolytic-like activity.. In combination with previous studies, these results suggest that cariprazine has a unique pharmacological profile and distinct dopamine D3 receptor-dependent mechanism of action that may be beneficial in the treatment of schizophrenia, bipolar disorder, and major depressive disorder.

Topics: Anhedonia; Animals; Anti-Anxiety Agents; Antidepressive Agents; Anxiety; Aripiprazole; Chronic Disease; Disease Models, Animal; Dopamine Agonists; Dose-Response Relationship, Drug; Imipramine; Male; Mice, Inbred C57BL; Mice, Knockout; Piperazines; Receptors, Dopamine D3; Stress, Psychological; Uncertainty

Negative symptoms and cognitive impairment associated with schizophrenia are strongly associated with poor functional outcome and reduced quality of life and remain an unmet clinical need. Cariprazine is a dopamine D3/D2 receptor partial agonist with preferential binding to D3 receptors, recently approved by the FDA for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder. The aim of this study is to evaluate effects of cariprazine in an animal model of cognitive deficit and negative symptoms of schizophrenia. Following sub-chronic PCP administration (2mg/kg, IP for 7 days followed by 7 days drug-free), female Lister Hooded rats were administered cariprazine (0.05, 0.1, or 0.25mg/kg, PO) or risperidone (0.16 or 0.1mg/kg, IP) before testing in novel object recognition (NOR), reversal learning (RL), and social interaction (SI) paradigms. As we have consistently demonstrated, sub-chronic PCP significantly impaired behavior in these tests. Deficits were significantly improved by cariprazine, in a dose dependent manner in the operant RL test with efficacy at lower doses in the NOR and SI tests. Locomotor activity was reduced at the highest doses of 0.1mg/kg and 0.25mg/kg in NOR and SI. Risperidone also reversed the PCP-induced deficit in all tests. In conclusion, cariprazine was effective to overcome PCP-induced deficits in cognition and social behavior in a thoroughly validated rat model in tests representing specific symptom domains in schizophrenia patients. These findings support very recent results showing efficacy of cariprazine in the treatment of negative symptoms in schizophrenia patients.

Topics: Animals; Antipsychotic Agents; Cognition; Cognition Disorders; Conditioning, Operant; Disease Models, Animal; Dopamine Agonists; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Exploratory Behavior; Female; Motor Activity; Nootropic Agents; Phencyclidine; Piperazines; Rats; Recognition, Psychology; Risperidone; Schizophrenia; Schizophrenic Psychology; Social Behavior

Current antipsychotic medication is largely ineffective against the negative and cognitive symptoms of schizophrenia. One promising therapeutic development is to design new molecules that balance actions on dopamine D2 and D3 receptors to maximise benefits and limit adverse effects. This study used two rodent paradigms to investigate the action of the dopamine D3-preferring D3/D2 receptor partial agonist cariprazine. In adult male rats, cariprazine (0.03-0.3 mg/kg i.p.), and the atypical antipsychotic aripiprazole (1-3 mg/kg i.p.) caused dose-dependent reversal of a delay-induced impairment in novel object recognition (NOR). Treating neonatal rat pups with phencyclidine (PCP) and subsequent social isolation produced a syndrome of behavioural alterations in adulthood including hyperactivity in a novel arena, deficits in NOR and fear motivated learning and memory, and a reduction and change in pattern of social interaction accompanied by increased ultrasonic vocalisations (USVs). Acute administration of cariprazine (0.1 and 0.3 mg/kg) and aripiprazole (3 mg/kg) to resultant adult rats reduced neonatal PCP-social isolation induced locomotor hyperactivity and reversed NOR deficits. Cariprazine (0.3 mg/kg) caused a limited reversal of the social interaction deficit but neither drug affected the change in USVs or the deficit in fear motivated learning and memory. Results suggest that in the behavioural tests investigated cariprazine is at least as effective as aripiprazole and in some paradigms it showed additional beneficial features further supporting the advantage of combined dopamine D3/D2 receptor targeting. These findings support recent clinical studies demonstrating the efficacy of cariprazine in treatment of negative symptoms and functional impairment in schizophrenia patients.

Topics: Analysis of Variance; Animals; Animals, Newborn; Antipsychotic Agents; Aripiprazole; Association Learning; Developmental Disabilities; Disease Models, Animal; Dose-Response Relationship, Drug; Excitatory Amino Acid Antagonists; Exploratory Behavior; Interpersonal Relations; Locomotion; Male; Memory Disorders; Phencyclidine; Piperazines; Rats; Recognition, Psychology; Schizophrenia

The aim of this study was to evaluate whether chronic treatment with cariprazine, a dopamine D2 and D3 receptor partial agonist with preferential binding to D3 receptors, shows antidepressant-like effects in the chronic mild stress (CMS)-induced anhedonia model. Male Wistar rats were subjected to the CMS procedure for 7 weeks; nonstressed animals served as controls. For the last 5 weeks of the CMS procedure, rats were injected once daily with vehicle, imipramine (10 mg/kg), aripiprazole (1 and 5 mg/kg), or cariprazine (0.01, 0.03, 0.065, 0.25, and 1.0 mg/kg). Activity in reversing CMS-induced decreases in consumption of 1% solution of sucrose was measured. CMS significantly reduced sucrose intake. Imipramine, and both doses of aripiprazole and cariprazine 0.03, 0.065, and 0.25 mg/kg significantly attenuated CMS-induced reductions in sucrose intake; the lowest and highest cariprazine doses (0.01 and 1 mg/kg) did not have this effect. Cariprazine showed greater potency (ED50=0.052) relative to aripiprazole (ED50=4.4) in this model. Thus, in the rat CMS model, cariprazine showed antidepressant-like action with greater potency than aripiprazole. These results suggest that cariprazine may have clinical utility in the treatment of depression and the negative symptoms of schizophrenia.

Topics: Anhedonia; Animals; Antidepressive Agents; Aripiprazole; Chronic Disease; Depressive Disorder; Dietary Sucrose; Disease Models, Animal; Dose-Response Relationship, Drug; Drinking Behavior; Imipramine; Male; Piperazines; Quinolones; Rats, Wistar; Stress, Psychological