Risperidone alters food intake, core body temperature, and locomotor activity in mice

Beyond animal models: revolutionizing neurodegenerative disease modeling using 3D in vitro organoids, microfluidic chips, and bioprinting

Neurodegenerative diseases (NDs) are characterized by uncontrolled loss of neuronal cells leading to a progressive deterioration of brain functions. The transition rate of numerous neuroprotective drugs against Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease, leading to FDA approval, is only 8-14% in the last two decades. Thus, in spite of encouraging preclinical results, these drugs have failed in human clinical trials, demonstrating that traditional cell cultures and animal models cannot accurately replicate human pathophysiology. Hence, in vitro three-dimensional (3D) models have been developed to bridge the gap between human and animal studies. Such technological advancements in 3D culture systems, such as human-induced pluripotent stem cell (iPSC)-derived cells/organoids, organ-on-a-chip technique, and 3D bioprinting, have aided our understanding of the pathophysiology and underlying mechanisms of human NDs. Despite these recent advances, we still lack a 3D model that recapitulates all the key aspects of NDs, thus making it difficult to study the ND's etiology in-depth. Hence in this review, we propose developing a combinatorial approach that allows the integration of patient-derived iPSCs/organoids with 3D bioprinting and organ-on-a-chip technique as it would encompass the neuronal cells along with their niche. Such a 3D combinatorial approach would characterize pathological processes thoroughly, making them better suited for high-throughput drug screening and developing effective novel therapeutics targeting NDs.

Thermoneutral housing does not rescue olanzapine-induced trabecular bone loss in C57BL/6J female mice

Antipsychotic drugs are prescribed to a wide range of individuals to treat mental health conditions including schizophrenia. However, antipsychotic drugs cause bone loss and increase fracture risk. We previously found that the atypical antipsychotic (AA) drug risperidone causes bone loss through multiple pharmacological mechanisms, including activation of the sympathetic nervous system in mice treated with clinically relevant doses. However, bone loss was dependent upon housing temperature, which modulates sympathetic activity. Another AA drug, olanzapine, has substantial metabolic side effects, including weight gain and insulin resistance, but it is unknown whether bone and metabolic outcomes of olanzapine are also dependent upon housing temperature in mice. We therefore treated eight week-old female mice with vehicle or olanzapine for four weeks, housed at either room temperature (23 °C) or thermoneutrality (28-30 °C), which has previously been shown to be positive for bone. Olanzapine caused significant trabecular bone loss (-13% BV/TV), likely through increased RANKL-dependent osteoclast resorption, which was not suppressed by thermoneutral housing. Additionally, olanzapine inhibited cortical bone expansion at thermoneutrality, but did not alter cortical bone expansion at room temperature. Olanzapine also increased markers of thermogenesis within brown and inguinal adipose depots independent of housing temperature. Overall, olanzapine causes trabecular bone loss and inhibits the positive effect of thermoneutral housing on bone. Understanding how housing temperature modulates the impact of AA drugs on bone is important for future pre-clinical studies, as well as for the prescription of AA drugs, particularly to older adults and adolescents who are most vulnerable to the effects on bone.

Housing Temperature Influences Atypical Antipsychotic Drug-Induced Bone Loss in Female C57BL/6J Mice

Atypical antipsychotic (AA) drugs, such as risperidone, are associated with endocrine and metabolic side effects, including impaired bone mineral density (BMD) acquisition and increased fracture risk. We have previously shown that risperidone causes bone loss through the sympathetic nervous system and that bone loss is associated with elevated markers of thermogenesis in brown and white adipose tissue. Because rodents are normally housed in sub‐thermoneutral conditions, we wanted to test whether increasing housing temperature would protect against bone loss from risperidone. Four weeks of risperidone treatment in female C57BL/6J mice at thermoneutral (28°C) housing attenuated risperidone‐induced trabecular bone loss and led to a low‐turnover bone phenotype, with indices of both bone formation and resorption suppressed in mice with risperidone treatment at thermoneutrality, whereas indices of bone resorption were elevated by risperidone at room temperature. Protection against trabecular bone loss was not absolute, however, and additional evidence of cortical bone loss emerged in risperidone‐treated mice at thermoneutrality. Taken together, these findings suggest thermal challenge may be in part responsible for bone loss with risperidone treatment and that housing temperature should be considered when assessing bone outcomes of treatments that impact thermogenic pathways. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Risperidone induced alterations in feeding and locomotion behavior of Caenorhabditis elegans

Antipsychotic drugs (APDs) are prescribed for the treatment of psychiatric illness. However, these drugs can also contribute to several developmental and behavioral disorders. Contemporary studies to evaluate the toxic effects of numerous atypical antipsychotics are reported to cause behavioral alteration at variable doses in mammals and nematodes. Risperidone, the second most prescribed drug in India, requires more exploration of its adverse effects on humans. Here, we explore effects on feeding behavior and locomotion patterns due to risperidone exposure in C. elegans model. The study targets to work out the toxic effects of risperidone exposure on feeding and locomotion behavior in addition to the expected pharmacological effects. N2 wild type strain was exposed in liquid culture assay for 2, 4, 6, 8, 10, and 12 hours with fixed 50 µM concentration. Feeding behavior was depleted due to inhibition in pharyngeal pumping varying from 11.05% - 45.67% in a time-dependent manner. Results of locomotion assay also show time-varying increase in reversals (4.9%-34.03%) and omega bends (26.23%-62.17%) with reduction in turn counts (29.07%- 42.2%) and peristaltic speed (31.38%-42.22%) amongst exposed groups as to control. The present work shows behavioral alterations due to risperidone exposure (50 µM) in C. elegans is in a time-dependent manner. The study concludes that risperidone exposure in C. elegans produces toxic effects with time, possibly caused by antagonizing other receptors apart from serotonin (5-H2T) and dopamine (D2) adding to its expected pharmacological effects.

Core body temperature changes in school-age children with circadian rhythm sleep-wake disorder

OBJECTIVE/BACKGROUND

Core body temperature (CBT) is considered a valuable marker for circadian rhythm. This study aimed to investigate the changes in CBT that are associated with the symptoms of circadian rhythm sleep-wake disorder (CRSWD) post-treatment in children.

PATIENTS/METHODS

Twenty-eight school-age children [10 boys and 18 girls; mean age (±standard deviation), 13.68 ± 0.93 years] who were admitted to our hospital with CRSWD underwent treatment for 6-8 weeks according to the following protocol: lights-out for sleep at 21:00; phototherapy for waking at 6:00 or 7:00; light exercise everyday (eg, a 20- to 30-min walk). CBT was continuously measured for 24 h on the first day of admission and on the first day after treatment.

RESULTS

The mean time of sleep onset/offset (±standard deviation; in hours:minutes) 1 week before admission and 1 week after treatment were 23:53 ± 2:26/9:58 ± 2:15 and 21:17 ± 0:19/6:46 ± 0:32, respectively. The mean times of sleep onset and offset measured post-treatment were significantly earlier than those measured pre-treatment (p < 0.001). The mean CBT and mean minimum CBT during sleep were significantly lower on the first day post-treatment than on the first day of admission (p = 0.011 and p < 0.001, respectively).

CONCLUSIONS

Symptom improvements in patients with CRSWD were associated with a decrease in CBT during sleep, suggesting that CBT may be a biomarker for improvements in CRSWD. These results help elucidate the cause of this sleep disorder.

University of Alabama at Birmingham Nathan Shock Center: comparative energetics of aging

The UAB Nathan Shock Center focuses on comparative energetics and aging. Energetics, as defined for this purpose, encompasses the causes, mechanisms, and consequences of the acquisition, storage, and use of metabolizable energy. Comparative energetics is the study of metabolic processes at multiple scales and across multiple species as it relates to health and aging. The link between energetics and aging is increasingly understood in terms of dysregulated mitochondrial function, altered metabolic signaling, and aberrant nutrient responsiveness with increasing age. The center offers world-class expertise in comprehensive, integrated energetic assessment and analysis from the level of the organelle to the organism and across species from the size of worms to rats as well as state-of-the-art data analytics. The range of services offered by our three research cores, (1) The Organismal Energetics Core, (2) Mitometabolism Core, and (3) Data Analytics Core, is described herein.

Self-Administration of Drugs in Mouse Models of Feeding and Obesity

Preclinical studies in mice often rely on invasive protocols, such as injections or oral gavage, to deliver drugs. These stressful routes of administration have significant effects on important metabolic parameters including food intake and body weight. Although an attractive option to circumvent this is to compound the drug in rodent food or dissolve it in water, these approaches also have limitations as they are affected by drug stability at room temperature for extended periods of time, the drug's solubility in water, and that the dosing is highly dependent on timing of food or water intake. The constant availability of the drug also limits translational relevance on how drugs are administered to patients. To overcome these limitations, drugs can be mixed with highly palatable food, such as peanut butter, allowing mice to self-administer compounds. Mice reliably and reproducibly consume the drug/peanut butter pellet in a short time frame. This approach facilitates a delivery approach with minimal stress compared with an injection or gavage. This protocol demonstrates the approach of drug preparation, animal acclimatization to placebo delivery, and drug delivery. The implications of this approach are discussed in studies related to timing of drug administration and the circadian rhythm.

Metabolomic profiles associated with a mouse model of antipsychotic-induced food intake and weight gain

Antipsychotic drugs (AP) are used to treat a multitude of psychiatric conditions including schizophrenia and bipolar disorder. However, APs also have metabolic side effects including increased food intake and body weight, but the underlying mechanisms remain unknown. We previously reported that minocycline (MINO) co-treatment abrogates olanzapine (OLZ)-induced hyperphagia and weight gain in mice. Using this model, we investigated the changes in the pharmacometabolome in the plasma and hypothalamus associated with OLZ-induced hyperphagia and weight gain. Female C57BL/6 mice were divided into groups and fed either i) control, CON (45% fat diet) ii) CON + MINO, iii) OLZ (45% fat diet with OLZ), iv) OLZ + MINO. We identified one hypothalamic metabolite indoxylsulfuric acid and 389 plasma metabolites (including 19 known metabolites) that were specifically associated with AP-induced hyperphagia and weight gain in mice. We found that plasma citrulline, tricosenoic acid, docosadienoic acid and palmitoleic acid were increased while serine, asparagine and arachidonic acid and its derivatives were decreased in response to OLZ. These changes were specifically blocked by co-treatment with MINO. These pharmacometabolomic profiles associated with AP-induced hyperphagia and weight gain provide candidate biomarkers and mechanistic insights related to the metabolic side effects of these widely used drugs.

Impaired hormonal regulation of appetite in schizophrenia: A narrative review dissecting intrinsic mechanisms and the effects of antipsychotics

Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects. Early hormonal alterations that might be associated with intrinsic mechanisms include low levels of leptin and glucagon-like peptide-1 (GLP-1) together with elevated insulin levels in first-episode psychosis (FEP) patients. However, evidence regarding low GLP-1 levels in FEP patients is based on one large study. In turn, multiple-episode schizophrenia patients show elevated levels of insulin, leptin and orexin A together with decreased levels of adiponectin. In addition, patients receiving olanzapine may present with low ghrelin levels. Post mortem studies have also demonstrated reduced number of neuropeptide Y neurons in the prefrontal cortex of patients with schizophrenia. Treatment with certain second-generation antipsychotics may also point to these alterations. Although our understanding of hormonal regulation of appetite in schizophrenia has largely been improved, several limitations and directions for future studies need to be addressed. This is of particular importance since several novel pharmacological interventions for obesity and diabetes have already been developed and translation of these developments to the treatment of cardiometabolic comorbidities in schizophrenia patients is needed.

Exploring mechanisms of increased cardiovascular disease risk with antipsychotic medications: Risperidone alters the cardiac proteomic signature in mice

Atypical antipsychotic (AA) medications including risperidone (RIS) and olanzapine (OLAN) are FDA approved for the treatment of psychiatric disorders including schizophrenia, bipolar disorder and depression. Clinical side effects of AA medications include obesity, insulin resistance, dyslipidemia, hypertension and increased cardiovascular disease risk. Despite the known pharmacology of these AA medications, the mechanisms contributing to adverse metabolic side-effects are not well understood. To evaluate drug-associated effects on the heart, we assessed changes in the cardiac proteomic signature in mice administered for 4 weeks with clinically relevant exposure of RIS or OLAN. Using proteomic and gene enrichment analysis, we identified differentially expressed (DE) proteins in both RIS- and OLAN-treated mouse hearts (p < 0.05), including proteins comprising mitochondrial respiratory complex I and pathways involved in mitochondrial function and oxidative phosphorylation. A subset of DE proteins identified were further validated by both western blotting and quantitative real-time PCR. Histological evaluation of hearts indicated that AA-associated aberrant cardiac gene expression occurs prior to the onset of gross pathomorphological changes. Additionally, RIS treatment altered cardiac mitochondrial oxygen consumption and whole body energy expenditure. Our study provides insight into the mechanisms underlying increased patient risk for adverse cardiac outcomes with chronic treatment of AA medications.

Adipose tissue as a target for second-generation (atypical) antipsychotics: A molecular view

Schizophrenia is a neuropsychiatric disorder that chronically affects 21 million people worldwide. Second-generation antipsychotics (SGAs) are the cornerstone in the management of schizophrenia. However, despite their efficacy in counteracting both positive and negative symptomatology of schizophrenia, recent clinical observations have described an increase in the prevalence of metabolic disturbances in patients treated with SGAs, including abnormal weight gain, hyperglycemia and dyslipidemia. While the molecular mechanisms responsible for these side-effects remain poorly understood, increasing evidence points to a link between SGAs and adipose tissue depots of white, brown and beige adipocytes. In this review, we survey the present knowledge in this area, with a particular focus on the molecular aspects of adipocyte biology including differentiation, lipid metabolism, thermogenic function and the browning/beiging process.

Impact of Chronic Risperidone Use on Behavior and Survival of 3xTg-AD Mice Model of Alzheimer's Disease and Mice With Normal Aging

Psychosis and/or aggression are common problems in dementia, and when severe or persistent, cause considerable patient distress and disability, caregiver stress, and early institutionalization. In 2005, the Food and Drug Administration (FDA) determined that atypical antipsychotics were associated with a significantly greater mortality risk compared to placebo, which prompted the addition of an FDA black-box warning. The American College of Neuropsychopharmacology (ACNP) White Paper, 2008, reviewed this issue and made clinical and research recommendations regarding the use of antipsychotics in dementia patients with psychosis and/or agitation. Increased mortality risk has also been described in cerebrovascular adverse events in elderly users of antipsychotics. In the present work, at the translational level, we used male 3xTg-AD mice (PS1M146V, APPSwe, tauP301L) at advanced stages of the disease reported to have worse survival than females, to study the behavioral effects of a low chronic dose of risperidone (0.1 mg/kg, s.c., 90 days, from 13 to 16 months of age) and its impact on long-term survival, as compared to mice with normal aging. Animals were behaviorally assessed for cognitive and BPSD (behavioral and psychological symptoms of dementia)-like symptoms in naturalistic and experimental conditions (open-field test, T-maze, social interaction, Morris water maze, and marble test) before and after treatment. Weight, basal glucose levels, and IPGTT (i.p. glucose tolerance test) were also recorded. Neophobia in the corner test was used for behavioral monitoring. Survival curves were recorded throughout the experiment until natural death. The benefits of risperidone were limited, both at cognitive and BPSD-like level, and mostly restricted to burying, agitation/vibrating tail, and other social behaviors. However, the work warns about a clear early mortality risk window during the treatment and long-lasting impact on survival. Reduced life expectancy and life span were observed in the 3xTg-AD mice, but total lifespan (36 months) recorded in C57BL/6 × 129Sv counterparts with normal aging was also truncated to 28 months in those with treatment. Sarcopenia at time of death was found in all groups, but was more severe in wild-type animals treated with risperidone. Therefore, the 3xTg-AD mice and their non-transgenic counterparts can be useful to delimitate critical time windows and for studying the physio-pathogenic factors and underlying causal events involved in this topic of considerable public health significance.

Antipsychotics-induced metabolic alterations: Recounting the mechanistic insights, therapeutic targets and pharmacological alternatives

Atypical antipsychotics (AAPs) are the drug of choice in the management of mental illnesses by virtue of their advantage over typical antipsychotics i.e. least tendency of producing extrapyramidal motor symptoms (EPS) or pseudoparkinsonism. Despite the clinical efficacy, AAPs produces troublesome adverse effects, particularly hyperphagia, hyperglycemia, dyslipidemia weight gain, diabetes mellitus, insulin resistance and QT prolongation which further develops metabolic and cardiac complications with subsequent reduction in life expectancy, poor patient compliance, and sudden death. AAPs-induced weight gain and metabolic alterations are increasing at an alarming rate and became an utmost matter of concern for psychopharmacotherapy. Diverse underlying mechanisms have been explored such as the interaction of AAPs with neurotransmitter receptors, alteration in food reward anticipation behavior, altered expressions of hypothalamic orexigenic and anorexigenic neuropeptides, histamine H₁ receptor-mediated hypothalamic AMP-activated protein kinase (AMPK) activation, increased blood leptin, ghrelin, pro-inflammatory cytokines. Antipsychotics induced imbalance in energy homeostasis, reduction in energy expenditure which is linked to altered expression of uncoupling proteins (UCP-1) in brown adipose tissue and reduced hypothalamic orexin expressions are emerging insights. In addition, alteration in gut-microbiota and subsequent inflammation, dyslipidemia, obesity, and diabetes after AAPs treatment are also associated with weight gain and metabolic alterations. Oral hypoglycemics and lipid-lowering drugs are mainly prescribed in the clinical management of weight gain associated with AAPs while many other pharmacological and nonpharmacological interventions also have been explored in different clinical and preclinical studies. In this review, we critically discuss the current scenario, mechanistic insights, biomarkers, and therapeutic alternatives for metabolic alterations associated with antipsychotics.

Risperidone-induced metabolic dysfunction is attenuated by Curcuma longa extract administration in mice

Antipsychotics, such as risperidone, increase food intake and induce alteration in glucose and lipid metabolism concomitantly with overweight and body fat increase, these biological abnormalities belong to the metabolic syndrome definition (high visceral adiposity, hypertriglyceridemia, hyperglycemia, low HDL-cholesterol and high blood pressure). Curcumin is a major component of traditional turmeric (Curcuma longa) which has been reported to improve lipid and glucose metabolism and to decrease weight in obese mice. We questioned the potential capacity of curcumin, contained in Curcuma longa extract (Biocurcuma™), to attenuate the risperidone-induced metabolic dysfunction. Two groups of mice were treated once a week, for 22 weeks, with intraperitoneal injection of risperidone (Risperdal) at a dose 12.5 mpk. Two other groups received intraperitoneal injection of the vehicle of Risperdal following the same schedule. Mice of one risperidone-treated groups and of one of vehicle-treated groups were fed a diet with 0.05% Biocurcuma™ (curcumin), while mice of the two other groups received the standard diet. Curcumin limited the capacity of risperidone to reduce spontaneous motricity, but failed to impede risperidone-induced increase in food intake. Curcumin did not reduce the capacity of risperidone to induce weight gain, but decreased visceral adiposity and decreased the risperidone-induced hepatomegaly, but not steatosis. Furthermore, curcumin repressed the capacity of risperidone to induce the hepatic over expression of enzymes involved in lipid metabolism (LXRα, FAS, ACC1, LPL, PPARγ, ACO, SREBP2) and decreased risperidone-induced glucose intolerance and hypertriglyceridemia. Curcumin decreased risperidone-induced increases in serum markers of hepatotoxicity (ALAT, ASAT), as well as of one major hepatic pro-inflammatory transcription factor (NFκB: p105 mRNA and p65 protein). These findings support that nutritional doses of curcumin contained in Curcuma longa extract are able to partially counteract the risperidone-induced metabolic dysfunction in mice, suggesting that curcumin ought to be tested to reduce the capacity of risperidone to induce the metabolic syndrome in human.

Molecular Mechanisms of Antipsychotic Drug-Induced Diabetes

Antipsychotic drugs (APDs) are widely prescribed to control various mental disorders. As mental disorders are chronic diseases, these drugs are often used over a life-time. However, APDs can cause serious glucometabolic side-effects including type 2 diabetes and hyperglycaemic emergency, leading to medication non-compliance. At present, there is no effective approach to overcome these side-effects. Understanding the mechanisms for APD-induced diabetes should be helpful in prevention and treatment of these side-effects of APDs and thus improve the clinical outcomes of APDs. In this review, the potential mechanisms for APD-induced diabetes are summarized so that novel approaches can be considered to relieve APD-induced diabetes. APD-induced diabetes could be mediated by multiple mechanisms: (1) APDs can inhibit the insulin signaling pathway in the target cells such as muscle cells, hepatocytes and adipocytes to cause insulin resistance; (2) APD-induced obesity can result in high levels of free fatty acids (FFA) and inflammation, which can also cause insulin resistance. (3) APDs can cause direct damage to β-cells, leading to dysfunction and apoptosis of β-cells. A recent theory considers that both β-cell damage and insulin resistance are necessary factors for the development of diabetes. In high-fat diet-induced diabetes, the compensatory ability of β-cells is gradually damaged, while APDs cause direct β-cell damage, accounting for the severe form of APD-induced diabetes. Based on these mechanisms, effective prevention of APD-induced diabetes may need an integrated approach to combat various effects of APDs on multiple pathways.

Atypical antipsychotics and effects on feeding: from mice to men

RATIONALE

So-called atypical antipsychotics (AAPs) are associated with varying levels of weight gain and associated metabolic disturbances, which in patients with serious mental illness (SMI) have been linked to non-compliance and poor functional outcomes. Mechanisms underlying AAP-induced metabolic abnormalities are only partially understood. Antipsychotic-induced weight gain may occur as a result of increases in food intake and/or changes in feeding.

OBJECTIVE

In this review, we examine the available human and preclinical literature addressing AAP-related changes in feeding behavior, to determine whether changes in appetite and perturbations in regulation of food intake could be contributing factors to antipsychotic-induced weight gain.

RESULTS

In general, human studies point to disruption by AAPs of feeding behaviors and food consumption. In rodents, increases in cumulative food intake are mainly observed in females; however, changes in feeding microstructure or motivational aspects of food intake appear to occur independent of sex.

CONCLUSIONS

The findings from this review indicate that the varying levels of AAP-related weight gain reflect changes in both appetite and feeding behaviors, which differ by type of AAP. However, inconsistencies exist among the studies (both human and rodent) that may reflect considerable differences in study design and methodology. Future studies examining underlying mechanisms of antipsychotic-induced weight gain are recommended in order to develop strategies addressing the serious metabolic side effect of AAPs.

Propranolol Attenuates Risperidone-Induced Trabecular Bone Loss in Female Mice

Atypical antipsychotic (AA) drugs cause significant metabolic side effects, and clinical data are emerging that demonstrate increased fracture risk and bone loss after treatment with the AA, risperidone (RIS). The pharmacology underlying the adverse effects on bone is unknown. However, RIS action in the central nervous system could be responsible because the sympathetic nervous system (SNS) is known to uncouple bone remodeling. RIS treatment in mice significantly lowered trabecular bone volume fraction (bone volume/total volume), owing to increased osteoclast-mediated erosion and reduced osteoblast-mediated bone formation. Daytime energy expenditure was also increased and was temporally associated with the plasma concentration of RIS. Even a single dose of RIS transiently elevated expression of brown adipose tissue markers of SNS activity and thermogenesis, Pgc1a and Ucp1. Rankl, an osteoclast recruitment factor regulated by the SNS, was also increased 1 hour after a single dose of RIS. Thus, we inferred that bone loss from RIS was regulated, at least in part, by the SNS. To test this, we administered RIS or vehicle to mice that were also receiving the nonselective β-blocker propranolol. Strikingly, RIS did not cause any changes in trabecular bone volume/total volume, erosion, or formation while propranolol was present. Furthermore, β2-adrenergic receptor null (Adrb2(-/-)) mice were also protected from RIS-induced bone loss. This is the first report to demonstrate SNS-mediated bone loss from any AA. Because AA medications are widely prescribed, especially to young adults, clinical studies are needed to assess whether β-blockers will prevent bone loss in this vulnerable population.

Effects of risperidone on energy balance in female C57BL/6J mice

OBJECTIVE

To investigate the effect of risperidone on energy expenditure and weight gain in female C57BL/6J mice.

DESIGN AND METHODS

Body weight and composition, food intake, energy expenditure, and activity were determined weekly. mRNA expression of uncoupling protein 1 in brown adipose tissue, orexin, and brain-derived neurotrophic factor in the hypothalamus were quantified using real-time PCR.

RESULTS

Risperidone tended to induce a greater body weight gain (P = 0.052) and significantly higher food intake (P = 0.038) relative to the placebo-treated group. Risperidone-treated mice had a higher resting energy expenditure (P = 0.001) and total energy expenditure (TEE) (P = 0.005) than the placebo group. There were no effects of treatment, time, and treatment by time on non-resting (or activity-related) energy expenditure between groups. Risperidone-treated mice showed a significantly lesser locomotor activity than placebo-treated mice over 3 weeks (P < 0.001). Risperidone induced a higher UCP1 mRNA (P = 0.003) and a lower orexin mRNA (P = 0.001) than placebo.

CONCLUSION

Risperidone-induced weight gain is associated with hyperphagia and a reduction in locomotor activity in C57BL/6J mice. Additionally, higher total and resting energy expenditure were accompanied by higher levels of UCP1 mRNA in BAT. The increased TEE could not offset the total intake of energy through risperidone-induced hyperphagia, therefore resulting in weight gain in female C57BL/6J mice.

Atypical antipsychotic drugs inhibit trabecular bone accrual in C57BL/6J mice

OBJECTIVE

To investigate the effects of the atypical antipsychotics drugs (AADs), olanzapine and risperidone, on femoral bone characteristics in female C57BL/6J mice.

METHODS

Mice were treated with placebo or AADs (olanzapine or risperidone) for 3-4 weeks. Femoral cortical and trabecular bone characteristics were determined using micro-computed tomography.

RESULTS

Olanzapine-treated mice tended to have lower trabecular bone volume (P = 0.088) and connectivity (P = 0.057) but no significant differences in bone density (P = 0.521) relative to controls. Risperidone-treated mice had significantly lower trabecular bone density (P = 0.001) and volume (P = 0.008), bone volume/total volume (P = 0.001), connectivity (P = 0.007), and trabecular number (P = 0.003) relative to controls. Cortical bone was not significantly affected by olanzapine or risperidone treatment.

CONCLUSION

AADs inhibited trabecular bone accrual in C57BL/6J mice suggesting that alternative treatment options may need to be considered for the schizophrenia patient with potential osteoporosis risk.

The effect of ziprasidone on body weight and energy expenditure in female rats

Ziprasidone, a novel antipsychotic agent with a unique receptor-binding profile, has been reported to have lower propensity for weight gain compared with other atypical antipsychotics. Here, we examined the effects of ziprasidone on resting energy expenditure, physical activity, thermogenesis, food intake, and weight gain in female Sprague-Dawley rats. Ziprasidone (20 mg/kg) or vehicle was administered once daily for 7 weeks; and body weight, food intake, resting energy expenditure, locomotor activity, colonic temperature on cold exposure, and abdominal fat were measured. Compared with control animals, ziprasidone-treated rats gained significantly less weight (P = .031), had a lower level of physical activity (P = .016), showed a higher resting energy expenditure (P < .001), and displayed a greater capacity for thermogenesis when subjected to cold (P < .001). In addition, ziprasidone-treated rats had a lower level of abdominal fat than did controls, although the difference was not significant. Ziprasidone had no effect on food intake. Our results indicate that, in female Sprague-Dawley rats, a 7-week treatment regimen of ziprasidone induces a significant decrease in weight gain by increasing resting energy expenditure without decreasing food intake and even with a lower level of physical activity. Further studies are needed to elucidate the precise mechanism of lower propensity of weight gain of ziprasidone.

Metabolic consequences of antipsychotic therapy: preclinical and clinical perspectives on diabetes, diabetic ketoacidosis, and obesity

Antipsychotic drugs, particularly second-generation antipsychotics (SGAs), have reduced the burden to society of schizophrenia, but many still produce excessive weight gain. A significant number of SGAs also act directly to impair glycemic control causing insulin resistance, impaired glucose tolerance and type 2 diabetes, and also rarely diabetic ketoacidosis (DKA). Schizophrenia itself is almost certainly causal in many endocrine and metabolic disturbances, making this population especially vulnerable to the adverse metabolic consequences of treatment with SGAs. Hence, there is an urgent need for a new generation of antipsychotic drugs that provide efficacy equal to the best of the SGAs without their liability to cause weight gain or type 2 diabetes. In the absence of such safe and effective alternatives to the SGAs, there is a substantial clinical need for the introduction of new antipsychotics without adverse metabolic effects and new antiobesity drugs to combat these metabolic side effects. We discuss the adverse metabolic consequences of schizophrenia, its exacerbation by a lack of social care, and the additional burden placed on patients by their medication. A critical evaluation of the animal models of antipsychotic-induced metabolic disturbances is provided with observations on their strengths and limitations. Finally, we discuss novel antipsychotic drugs with a lower propensity to increase metabolic risk and adjunctive medications to mitigate the adverse metabolic actions of the current generation of antipsychotics.

CSF-hypocretin-1 levels in patients with major depressive disorder compared to healthy controls

Depressive patients exhibit symptoms of impaired regulation of wakefulness with hyperarousal and agitation as well as difficulties to falling asleep and preserving sleep continuity. Changes in hypocretin (hcrt) levels as polypeptides with impact on arousal and sleep-wake-regulation have been discussed in affective disorders but have not been investigated in patients with solely unipolar depression in comparison to healthy controls. In the present study, cerebrospinal fluid (CSF) levels of hcrt-1 for the first time were analyzed in patients with major depressive disorder (MDD) without psychiatric comorbidities and compared with levels in healthy controls. In 17 inpatients with MDD (mean Hamilton Depression Rating Scale 13.9 ± 7.4) and 10 healthy controls, CSF-hcrt-1 levels were measured using a fluorescence immunoassay (FIA). The mean hcrt-1 CSF levels in patients with MDD (74.3 ± 17.8pg/ml) did not differ compared to that of healthy controls (82.8 ± 22.1pg/ml). Hcrt-1 levels did not correlate with the severity of depressive episode, the symptoms of depression or the number of episodes. Although autonomic and neurohumoral signs of hyperarousal are common in MDD, hcrt-1 levels in CSF were not found to be altered in MDD compared to healthy controls. Whether hcrt-1 levels are altered in depressive patients exhibiting impaired vigilance regulation has to be investigated in further studies combining measures of CSF-hcrt-1 with electroencephalography.

DRD2 promoter region variation predicts antipsychotic-induced weight gain in first episode schizophrenia

Many antipsychotic medications carry a substantial liability for weight gain, and one mechanism common to all antipsychotics is binding to the dopamine D2 receptor. We therefore examined the relationship between -141C Ins/Del (rs1799732), a functional promoter region polymorphism in DRD2, and antipsychotic-induced weight gain in 58 first episode schizophrenia patients enrolled in a randomized trial of risperidone versus olanzapine. Carriers of the deletion allele (n=29) were compared with Ins/Ins homozygotes (noncarriers, n=29) in a mixed model encompassing 10 weight measurements over 16 weeks. Deletion allele carriers showed significantly more weight gain after 6 weeks of treatment regardless of assigned medication. Although deletion carriers were prescribed higher doses of olanzapine (but not risperidone), dose did not seem to account for the genotype effects on weight gain. Given earlier evidence that deletion carriers show reduced symptom response to medication, additional study of appropriate treatment options for these patients seems warranted.

Overweight induced by chronic risperidone exposure is correlated with overexpression of the SREBP-1c and FAS genes in mouse liver

Weight gain and metabolic disturbances, such as dyslipidemia and hyperglycaemia, are common side effects of most antipsychotic drugs, including risperidone. The aim of this study was to investigate the effects of chronic treatment with risperidone on body weight, fat accumulation, liver weight, and hepatic expression of key genes involved in lipid metabolism in female mice. We also addressed the mechanism of risperidone induction of metabolic side effects by exploring its effect on lipid and cholesterol metabolism in primary cultures of rat hepatocytes. Eleven weeks of treatment with long-acting risperidone (12.5 mpk/week) resulted in a significant weight gain associated with an increase of liver and adipose tissue weight. These effects were positively correlated with hepatic mRNA induction of two key genes involved in lipogenesis: sterol regulatory element binding protein-1c (SREBP-1c) and fatty acid synthase (FAS). Furthermore, in line with these in vivo results, risperidone elicited significant inductions of SREBP-1 maturation and FAS mRNA expression in primary cultures of rat hepatocytes associated with an increase of free fatty acid, triacylglycerol, and phospholipid synthesis as assessed by acetate incorporation. The current investigations underscore the usefulness of a mouse model to study the weight gain observed with risperidone treatment in humans. This study shows that risperidone induces similar effects in the liver (in vivo) and in hepatocyte cell cultures (in vitro) on the expression of key genes and/or proteins that control lipid metabolism. This suggests that risperidone could alter lipid metabolism in the liver and induce weight gain in a way that is partly independent of its action on the central nervous system.

Olanzapine treatment and metabolic dysfunction: a dose response study in female Sprague Dawley rats

Second generation antipsychotics are commonly prescribed for the treatment of schizophrenia, however some can induce metabolic dysfunction side-effects such as weight gain, obesity and diabetes. Clinical reports suggest olanzapine alters satiety signals, although findings appear conflicting. Previous animal model studies have utilised a range of olanzapine dosages, however the dosage that better mimics the human scenario of olanzapine-induced weight gain is unclear. Female Sprague-Dawley rats were treated orally, three times daily with olanzapine (0.25mg/kg, 0.5mg/kg, 1.0mg/kg, 2.0mg/kg), self-administered in a sweet cookie dough pellet at eight-hourly intervals) or vehicle (n=12/group) for 14-days. Olanzapine orally self-administered in multiple doses (eight-hourly intervals) may circumvent a drop in plasma drug concentration and ensure the maintenance of a consistently high olanzapine level in the rat. Olanzapine increased body weight (0.5mg/kg, 1.0mg/kg, 2.0mg/kg), food intake (2.0mg/kg) and feeding efficiency (0.5-2.0mg/kg), with no effect on water intake. Subcutaneous inguinal (1.0mg/kg, 2.0mg/kg) and intra-abdominal perirenal fat were increased (2.0mg/kg), but not interscapula brown adipose tissue. Olanzapine increased circulating ghrelin and cholecystokinin, but had no effect on peptide YY((3-36)). Olanzapine decreased insulin (0.25-2.0mg/kg) and locomotor activity in the open field arena (0.5-2.0mg/kg). A low dosage of 0.25mg/kg olanzapine had no effect on most parameters measured. Olanzapine-induced weight gain is associated with hyperphagia, enhanced feeding efficiency and adiposity, decreased locomotor activity and altered satiety signaling. The animal model used in the present study of self-administered oral olanzapine treatment (t.i.d.) at a dosage range of 0.5-2.0mg/kg (but not 0.25mg/kg) mimics aspects of the clinic.

Different antipsychotics elicit different effects on magnocellular oxytocinergic and vasopressinergic neurons as revealed by Fos immunohistochemistry

Acute administration of antipsychotics elicits regionally distinct patterns of Fos expression in the rat brain. Stimulation of oxytocin (OXY) and vasopressin (AVP) release in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei indicates that antipsychotics may play a role in autonomic, neuroendocrine, and behavioral processes. This study was focused to reveal the responsiveness of hypothalamic OXY- and AVP- producing magnocellular neurons, in terms of quantitative and topographical distinctions, to antipsychotics displaying different pharmacological profiles. Naive male Wistar rats were injected intraperitoneally with haloperidol (1 mg/kg), clozapine (30 mg/kg), olanzapine (30 mg/kg), risperidone (2mg/kg), and vehicle (5% chremophor) and were sacrificed 60 min later by a fixative. Fos, Fos/OXY, and Fos/AVP labelings were visualized by immunohistochemistry in the SON, 5 accessory (ACS) cell groups, and 4 distinct PVN subdivisions using a computerized light microscope. Most apparent activation of single Fos, Fos/OXY, and Fos/AVP cells was induced by clozapine and olanzapine; effects of risperidone and haloperidol were substantially lower; no colocalizations were revealed in naive or vehicle treated control rats. The data indicate the existence of a substantial diversity in the stimulatory effect of the selected antipsychotics on quantity of Fos, Fos/OXY, and Fos/AVP immunostainings with the preferential action of the atypicals clozapine over olanzapine and little effects of risperidone and haloperidol. Variabilities in Fos distribution in the PVN, SON, and ACS induced by antipsychotics may be helpful to understand more precisely the extent of their extra-forebrain actions with possible presumption of their functional impact and side effect consequences.

Repetitive self-grooming behavior in the BTBR mouse model of autism is blocked by the mGluR5 antagonist MPEP

Autism is a neurodevelopmental disorder characterized by abnormal reciprocal social interactions, communication deficits, and repetitive behaviors with restricted interests. BTBR T+tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of autism, including well-replicated deficits in reciprocal social interactions and social approach, unusual patterns of ultrasonic vocalization, and high levels of repetitive self-grooming. These phenotypes offer straightforward behavioral assays for translational investigations of pharmacological compounds. Two suggested treatments for autism were evaluated in the BTBR mouse model. Methyl-6-phenylethynyl-pyridine (MPEP), an antagonist of the mGluR5 metabotropic glutamate receptor, blocks aberrant phenotypes in the Fmr1 mouse model of Fragile X, a comorbid neurodevelopmental disorder with autistic features. Risperidone has been approved by the United States Food and Drug Administration for the treatment of irritability, tantrums, and self-injurious behavior in autistic individuals. We evaluated the actions of MPEP and risperidone on two BTBR phenotypes, low sociability and high repetitive self-grooming. Open field activity served as an independent control for non-social exploratory activity and motor functions. C57BL/6J (B6), an inbred strain with high sociability and low self-grooming, served as the strain control. MPEP significantly reduced repetitive self-grooming in BTBR, at doses that had no sedating effects on open field activity. Risperidone reduced repetitive self-grooming in BTBR, but only at doses that induced sedation in both strains. No overall improvements in sociability were detected in BTBR after treatment with either MPEP or risperidone. Our findings suggest that antagonists of mGluR5 receptors may have selective therapeutic efficacy in treating repetitive behaviors in autism.