Exercise intervention for preventing risperidone-induced dyslipidemia and gluco-metabolic disorders in female juvenile rats

The effects of risperidone and voluntary exercise intervention on synaptic plasticity gene expressions in the hippocampus and prefrontal cortex of juvenile female rats

BACKGROUND

Psychiatric disorders and antipsychotics are associated with impaired neuroplasticity, while physical exercise has been reported to enhance neuroplasticity and improve cognitive and affective processes. Therefore, this study hypothesizes that voluntary exercise can enhance synaptic plasticity in juvenile rats disrupted by risperidone, a commonly prescribed antipsychotic for pediatric patients.

METHODS

Thirty-two juvenile female rats were randomly assigned to Vehicle+Sedentary, Risperidone (0.9mg/kg; b.i.d)+Sedentary, Vehicle+Exercise (three hours daily access to running wheels), and Risperidone+Exercise groups for four week treatment. Brains were collected for further analysis.

RESULTS

In the hippocampus, the mRNA expressions of Bdnf, Ntrk2, and Grin2b were increased by risperidone and exercise intervention. Exercise upregulated expression of Grin1 and Grin2a. Syn1 and Syp mRNA expression were enhanced by exercise in the risperidone-treated group. The expression of both Mfn1 and Drp1 mRNA were decreased by risperidone-only treatment. In the prefrontal cortex, Bdnf and Dlg4 expression was upregulated by exercise, while the Ntrk2 expression was reduced by risperidone and reversed by exercise. The Mfn1 mRNA expression was decreased by risperidone with or without voluntary exercise. The risperidone-decreased Ppargc1α gene expression was enhanced by exercise.

CONCLUSION

Risperidone affects synaptic plasticity through a complex mechanism in female juvenile rats: enhancing certain key genes in the hippocampus while inhibiting genes essential for mitochondrial function. In line with our hypothesis, voluntary exercise promotes genes beneficial for synaptic plasticity and enhances specific genes reduced by risperidone, in female juvenile rats.

Olanzapine Modulate Lipid Metabolism and Adipose Tissue Accumulation via Hepatic Muscarinic M3 Receptor-Mediated Alk-Related Signaling

Olanzapine is an atypical antipsychotic drug and a potent muscarinic M3 receptor (M3R) antagonist. Olanzapine has been reported to cause metabolic disorders, including dyslipidemia. Anaplastic lymphoma kinase (Alk), a tyrosine kinase receptor well known in the pathogenesis of cancer, has been recently identified as a key gene in the regulation of thinness via the regulation of adipose tissue lipolysis. This project aimed to investigate whether Olanzapine could modulate the hepatic Alk pathway and lipid metabolism via M3R. Female rats were treated with Olanzapine and/or Cevimeline (an M3R agonist) for 9 weeks. Lipid metabolism and hepatic Alk signaling were analyzed. Nine weeks' treatment of Olanzapine caused metabolic disturbance including increased body mass index (BMI), fat mass accumulation, and abnormal lipid metabolism. Olanzapine treatment also led to an upregulation of Chrm3, Alk, and its regulator Ptprz1, and a downregulation of Lmo4, a transcriptional repressor of Alk in the liver. Moreover, there were positive correlations between Alk and Chrm3, Alk and Ptprz1, and a negative correlation between Alk and Lmo4. However, cotreatment with Cevimeline significantly reversed the lipid metabolic disturbance and adipose tissue accumulation, as well as the upregulation of the hepatic Alk signaling caused by Olanzapine. This study demonstrates evidence that Olanzapine may cause metabolic disturbance by modulating hepatic Alk signaling via M3R, which provides novel insight for modulating the hepatic Alk signaling and potential interventions for targeting metabolic disorders.

Antipsychotic Drug-Induced Increases in Peripheral Catecholamines are Associated With Glucose Intolerance

The second-generation antipsychotic drugs are widely used in the field of psychiatry, for an expanding number of different conditions. While their clinical efficacy remains indispensable, many of the drugs can cause severe metabolic side-effects, resulting in an increased risk of developing cardiometabolic disorders. The physiological basis of these side-effects remains an ongoing area of investigation. In the present study, we examined the potential role of peripheral catecholamines in antipsychotic-induced glucose intolerance. Adult female rats were acutely treated with either the first-generation antipsychotic drug haloperidol (0.1, 0.5 or 1 mg/kg) or the second-generation drugs risperidone (0.25, 1.0 or 2.5 mg/kg), olanzapine (1.5, 7.5 or 15 mg/kg) or clozapine (2, 10 or 20 mg/kg) or vehicle. Fasting glucose levels were measured and then animals were subjected to the intraperitoneal glucose tolerance test. Levels of peripheral norepinephrine, epinephrine and dopamine were concurrently measured in the same animals 75, 105 and 135 min after drug treatment. All antipsychotics caused glucose intolerance, with strongest effects by clozapine > olanzapine > risperidone > haloperidol. Plasma catecholamines were also increased by drug treatment, with greatest effects for norepinephrine and epinephrine caused by clozapine > risperidone > olanzapine > haloperidol. Importantly, there were strong and statistically significant associations between norepinephrine/epinephrine levels and glucose intolerance for all drugs. These findings confirm that increases in peripheral catecholamines co-occur in animals that exhibit antipsychotic-induced glucose intolerance, and these effects are strongly associated with each other, providing further evidence for elevated catecholamines as a substrate for antipsychotic metabolic side-effects.

Deciphering Risperidone-Induced Lipogenesis by Network Pharmacology and Molecular Validation

BACKGROUND

Risperidone is an atypical antipsychotic that can cause substantial weight gain. The pharmacological targets and molecular mechanisms related to risperidone-induced lipogenesis (RIL) remain to be elucidated. Therefore, network pharmacology and further experimental validation were undertaken to explore the action mechanisms of RIL.

METHODS

RILs were systematically analyzed by integrating multiple databases through integrated network pharmacology, transcriptomics, molecular docking, and molecular experiment analysis. The potential signaling pathways for RIL were identified and experimentally validated using gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) analysis.

RESULTS

Risperidone promotes adipocyte differentiation and lipid accumulation through Oil Red O staining and reverse transcription-polymerase chain reaction (RT-PCR). After network pharmacology and GO analysis, risperidone was found to influence cellular metabolism. In addition, risperidone influences adipocyte metabolism, differentiation, and lipid accumulation-related functions through transcriptome analysis. Intersecting analysis, molecular docking, and pathway validation analysis showed that risperidone influences the adipocytokine signaling pathway by targeting MAPK14 (mitogen-activated protein kinase 14), MAPK8 (mitogen-activated protein kinase 8), and RXRA (retinoic acid receptor RXR-alpha), thereby inhibiting long-chain fatty acid β-oxidation by decreasing STAT3 (signal transducer and activator of transcription 3) expression and phosphorylation.

CONCLUSION

Risperidone increases adipocyte lipid accumulation by plausibly inhibiting long-chain fatty acid β-oxidation through targeting MAPK14 and MAPK8.

Kidney plays an important role in ketogenesis induced by risperidone and voluntary exercise in juvenile female rats

The positive role of ketone bodies in the treatment for mental disorders has been demonstrated. Ketogenesis can be triggered by not only exercise and diet but also metabolic disorders. This study aimed to explore the role of risperidone and exercise in ketogenesis. Thirty-two juvenile female Sprague Dawley rats were randomly assigned into four groups: Vehicle-Sedentary, Risperidone (0.9 mg/kg; b.i.d)-Sedentary, Vehicle-Exercise (three hours daily access to running wheels) and Risperidone-Exercise groups for four weeks. Exercise-intervention significantly ameliorated the risperidone-induced increase in white adipose mass, fasting plasma triglyceride and insulin levels. Compared to the vehicle-exercise group, the risperidone-exercise group had significantly higher plasma β-hydroxybutyrate (β-HB) level, which had a positive correlation with plasma non-esterified fatty acid levels. Risperidone-treatment upregulated expression of ketogenic key enzyme, mitochondrial 3-hydroxy-3-methyl-glutaryl-CoA synthase 2 (HMGCS2) in the kidney rather than liver. Exercise-intervention significantly enhanced renal carnitine palmitoyltransferase1A (CPT1A) expression. These results suggested that the kidney plays an important role in ketogenesis associated with risperidone and exercise. Therefore, it is important to monitor the levels of plasma ketone bodies while exercise intervention is utilized to prevent risperidone-induced metabolic disorders in young people.

A comparison of the metabolic side-effects of the second-generation antipsychotic drugs risperidone and paliperidone in animal models

BACKGROUND

The second generation antipsychotic drugs represent the most common form of pharmacotherapy for schizophrenia disorders. It is now well established that most of the second generation drugs cause metabolic side-effects. Risperidone and its active metabolite paliperidone (9-hydroxyrisperidone) are two commonly used antipsychotic drugs with moderate metabolic liability. However, there is a dearth of preclinical data that directly compares the metabolic effects of these two drugs, using sophisticated experimental procedures. The goal of the present study was to compare metabolic effects for each drug versus control animals.

METHODS

Adult female rats were acutely treated with either risperidone (0.1, 0.5, 1, 2, 6 mg/kg), paliperidone (0.1, 0.5, 1, 2, 6 mg/kg) or vehicle and subjected to the glucose tolerance test; plasma was collected to measure insulin levels to measure insulin resistance with HOMA-IR. Separate groups of rats were treated with either risperidone (1, 6 mg/kg), paliperidone (1, 6 mg/kg) or vehicle, and subjected to the hyperinsulinemic euglycemic clamp.

RESULTS

Fasting glucose levels were increased by all but the lowest dose of risperidone, but only with the highest dose of paliperidone. HOMA-IR increased for both drugs with all but the lowest dose, while the three highest doses decreased glucose tolerance for both drugs. Risperidone and paliperidone both exhibited dose-dependent decreases in the glucose infusion rate in the clamp, reflecting pronounced insulin resistance.

CONCLUSIONS

In preclinical models, both risperidone and paliperidone exhibited notable metabolic side-effects that were dose-dependent. Differences between the two were modest, and most notable as effects on fasting glucose.