Beta-Endorphin and Oxytocin in Patients with Alcohol Use Disorder and Comorbid Depression

Background: The neuropeptides β-endorphin and oxytocin are released into the bloodstream as hormones from the pituitary gland but also have an important function as neuroregulators in the forebrain. The blood levels of both polypeptides have been shown to reflect depressive symptoms. β-Endorphin, in particular, is also involved in abstinence from alcohol. Methods: The serum levels of β-endorphin and oxytocin were measured during the early withdrawal phase in patients with alcohol use disorder (AUD) with (N = 35) or without (N = 45) depressive comorbidity and compared with those in healthy volunteers (N = 23). In addition to comparing the groups, the study examined whether serum levels correlated with various psychometric measures of dependence, depression and aggression, as well as with clinical characteristics of dependence. Results: Both serum levels of beta-endorphin and oxytocin were significantly lower in patients than those in healthy controls (p = 0.011 for β-endorphin and p = 0.005 for oxytocin, Kruskal–Wallis test). In patients with depressive comorbidity, the significance was greatest (p = 0.005 for β-endorphin and p = 0.004 for oxytocin, U-test). There was no correlation with clinical or psychometric parameters (p > 0.05, Spearman test), but beta-endorphin levels did correlate significantly with physical aggression (p = 0.026, Spearman test). Conclusions: Serum levels of β-endorphin and oxytocin are lower in patients with AUD, particularly in those with depressive comorbidity. β-Endorphin levels correlated with physical aggression according to the Buss–Durkee (BDHI) estimates

Search for Possible Associations of FTO Gene Polymorphic Variants with Metabolic Syndrome, Obesity and Body Mass Index in Schizophrenia Patients

PURPOSE: Metabolic syndrome (MetS) is characterized by abdominal obesity, hyperglycaemia, dyslipidaemia and hypertension. FTO gene has been implicated in the pathogenesis of obesity, but the available scientific data concerning their relationship to antipsychotic drug-induced obesity and metabolic syndrome is still incomplete and inconsistent, which indicates that continuing the investigation of this gene’s role is necessary. PATIENTS AND METHODS: In the present study, 517 patients with schizophrenia underwent antipsychotic drug treatment, and two groups were identified: patients with MetS and without MetS. Genotyping of 6 SNPs in the FTO gene was performed, and the results analyzed using R-programme. RESULTS: We performed a statistical analysis to identify possible associations of the frequencies of genotypes and alleles of the studied polymorphisms with the presence of metabolic syndrome in schizophrenia patients, with the presence of abdominal obesity, and with an increased body mass index. The rs7185735 polymorphism did not meet the Hardy-Weinberg criterion and was excluded. After correcting for differences in age, gender and duration of illnesses, none of the variants was shown to be related to metabolic syndrome or abdominal obesity, but rs9939609, rs1421085, rs3751812 and rs8050136 were associated with body mass index. CONCLUSION: The present study provides additional support for these SNP’s roles as a pharmacogenetic biomarker that may become useful in the framework of the personalized medicine approach

Genetic Polymorphisms of 5-HT Receptors and Antipsychotic-Induced Metabolic Dysfunction in Patients with Schizophrenia

Background: Antipsychotic-induced metabolic syndrome (MetS) is a multifactorial disease with a genetic predisposition. Serotonin and its receptors are involved in antipsychotic-drug-induced metabolic disorders. The present study investigated the association of nine polymorphisms in the four 5-hydroxytryptamine receptor (HTR) genes HTR1A, HTR2A, HTR3A, and HTR2C and the gene encoding for the serotonin transporter SLC6A4 with MetS in patients with schizophrenia. Methods: A set of nine single-nucleotide polymorphisms of genes of the serotonergic system was investigated in a population of 475 patients from several Siberian regions (Russia) with a clinical diagnosis of schizophrenia. Genotyping was performed and the results were analyzed using chi-square tests. Results: Polymorphic variant rs521018 (HTR2C) was associated with higher body mass index in patients receiving long-term antipsychotic therapy, but not with drug-induced metabolic syndrome. Rs1150226 (HTR3A) was also associated but did not meet Hardy-Weinberg equilibrium. Conclusions: Our results indicate that allelic variants of HTR2C genes may have consequences on metabolic parameters. MetS may have too complex a mechanistic background to be studied without dissecting the syndrome into its individual (causal) components

Gene Polymorphisms of Hormonal Regulators of Metabolism in Patients with Schizophrenia with Metabolic Syndrome

Background: Metabolic syndrome (MetS) is a common complication of long-term treatment of persons with schizophrenia taking (atypical) antipsychotics. In this study, we investigated the existence of an association with polymorphisms of genes for four hormones that regulate energy metabolism. Methods: We recruited 517 clinically admitted white patients (269M/248F) with a verified diagnosis of schizophrenia (ICD-10) and with a stable physical condition. Participants were classified for having or not having MetS and genotyped for 20 single-nucleotide polymorphisms (SNPs) in the genes encoding insulin-induced gene 2 (INSIG2), ghrelin (GHRL), leptin (LEP), and leptin receptor (LEPR). Results: The 139 patients (26.9%) with MetS were significantly more likely to be women, older, and ill longer, and had a larger body mass index (BMI). Four polymorphisms (rs10490624, rs17587100, rs9308762, and rs10490816) did not meet the Hardy–Weinberg equilibrium (HWE) criterion and were excluded. Only genotypes and alleles of the rs3828942 of LEP gene (chi2 = 7.665, p = 0.022; chi2 = 5.136, p = 0.023) and the genotypes of the rs17047718 of INSIG2 gene (chi2 = 7.7, p = 0.021) had a significant association with MetS. Conclusions: The results of our study suggest that the LEP and INSIG2 genes play a certain causal role in the development of MetS in patients with schizophrenia

The Gender-Specific Association of DRD2 Polymorphism with Metabolic Syndrome in Patients with Schizophrenia

BACKGROUND: Metabolic syndrome is widespread in patients with schizophrenia receiving long-term antipsychotic therapy. Dopamine D2 receptors play an important role in mediating both the therapeutic actions of antipsychotics and their side effects. The present study examined the association of two polymorphisms of the DRD2 gene with metabolic syndrome in patients with schizophrenia. METHODS: We examined 517 patients from several regions of Siberia (Russia) with a clinical diagnosis of schizophrenia. Genotyping of two single nucleotide polymorphisms rs1799732 and rs4436578 of the dopamine D2 receptor gene (DRD2) was performed in a population of 471 patients. The results were analyzed using chi-square tests. RESULTS: Functional polymorphism rs1799732 of the DRD2 gene is associated with drug-induced metabolic syndrome in women with schizophrenia. CONCLUSIONS: Our results show that the DRD2 gene may be involved in the pathogenesis of metabolic disorders in patients with schizophrenia. Further analysis of possible genetic markers will allow for personalized treatment with minimal side effects and optimal efficacy. This which seems relevant in light of the recent focus on improving the quality of life and ensuring a high level of social adaptation of patients with schizophrenia

Exploring Brain Derived Neurotrophic Factor and Cell Adhesion Molecules as Biomarkers for the Transdiagnostic Symptom Anhedonia in Alcohol Use Disorder and Comorbid Depression

Background: Alcohol Use Disorder (AUD) and depressive disorder often co-exist and have a shared heritability. This study aimed to investigate Brain-Derived Neurotrophic Factor (BDNF) and three Cell Adhesion Molecules (CAMs) as transdiagnostic biomarkers in AUD and depression co-morbidity. Methods: In a cross-sectional study, patients with AUD (n=22), AUD and depression (n=19), and healthy controls (n=20) were examined. Depression and anxiety severity were assessed using the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale. Anhedonia, alcohol use and dependence, craving, and social adaptation were assessed through self-report questionnaires. BDNF and CAM concentrations in peripheral serum were measured after overnight fasting using a Luminex assay. After controlling for age and gender, biomarker levels were compared across groups. The association between biomarker concentrations and symptom severity scales were explored using correlation and multiple regression analyses. Results: BDNF and Neuronal CAM were lower in patients with AUD with and without depression compared to healthy controls. No differences were observed for Vascular CAM-1 and Interstitial CAM-1. BDNF correlated negatively with anhedonia levels. BDNF, age and gender together explained 21% of variability in anhedonia levels. Conclusion: This pilot study suggests that peripheral levels of BDNF and NCAM might be reduced in AUD with and without comorbid mood disorder. Since low BDNF levels were associated with self- reported anhedonia across these conditions, BDNF and anhedonia might reflect transdiagnostic aspects involved in AUD and depression

Association between 8 P-glycoprotein (MDR1/ABCB1) gene polymorphisms and antipsychotic drug-induced hyperprolactinaemia

Introduction: Hyperprolactinaemia, a common adverse effect of antipsychotic drugs, is primarily linked to blockade of dopamine D2 receptors in the pituitary gland. Certain antipsychotic drugs, such as, for example risperidone and paliperidone, are more likely to induce hyperprolactinaemia compared to others. This effect is probably caused by a relatively high blood/brain concentration ratio, a consequence of being a substrate of P-glycoprotein. Genetic variants of P-glycoprotein with changed functional activity might influence the potential of risperidone and paliperidone to cause hyperprolactinaemia as the altered blood/brain concentration ratio would lead to a reduced therapeutic drug level within essential brain areas making dose adaptations necessary. This increases exposure of dopamine D2 receptors within the pituitary gland. Aims: To investigate possible associations between MDR1/ABCB1 gene polymorphisms and antipsychotic drug-induced hyperprolactinaemia in Russian patients with schizophrenia and to determine possible differences between risperidone/paliperidone and other antipsychotics. Methods: In total, 446 patients with schizophrenia were included from 3 psychiatric hospitals in Siberia. Blood samples were obtained in a cross-sectional study design for DNA extraction and prolactin measurement. Associations between hyperprolactinaemia and 8 MDR1/ABCB1 gene-polymorphisms were assessed using logistic regression analysis accounting for covariates. The analysis was repeated in a patient subgroup using risperidone or paliperidone. Results: We did not observe an association between any of the 8 single nucleotide polymorphisms and the prevalence of antipsychotic-induced hyperprolactinaemia in the total patient population. However, in the risperidone/paliperidone subgroup, the single nucleotide polymorphism rs2032582 (G2677T) was found to be negatively associated with risperidone/paliperidone-induced hyperprolactinaemia. Conclusion: This study revealed a significant association between the ABCB1 gene polymorphism rs2032582 (G2677T) and risperidone/paliperidone-induced hyperprolactinaemia

Association of polymorphism in the dopamine receptors and transporter genes with hyperprolactinemia in patients with schizophrenia

Association of polymorphism in the dopamine receptors and transporter genes with hyperprolactinemia in patients with schizophrenia D. Osmanova(1), A.S. Boiko(1), O.Y. Fedorenko(1), I.V. Pozhidaev(1), M.B. Freidin(2), E.G. Kornetova(3), S.A. Ivanova(1), B. Wilffert(4), A.J.M. Loonen(5) (1)Mental Health Research Institute- Tomsk NRMC, Laboratory of Molecular Genetics and Biochemistry, Tomsk, Russia (2)Research Institute of Medical Genetics, Tomsk NRMC, Laboratory of Population Genetics, Tomsk, Russia (3)Mental Health Research Institute- Tomsk NRMC, Department of Clinical and Social Psychiatry and Addiction, Tomsk, Russia (4)Groningen Research Institute of Pharmacy, Pharmacotherapy and Clinical Pharmacology, Groningen, The Netherlands (5)Groningen Research Institute of Pharmacy, Pharmacotherapy in Psychiatric Patients, Groningen, The Netherlands Background: Long-term antipsychotic drug use remains the mainstay of treatment for patients with schizophrenia. However, pharmacotherapy with these drugs is complicated by several troublesome side effects, including hyperprolactinemia (HP). Prolactin secretion is persistently inhibited by dopamine, and antipsychotic drugs are believed to increase prolactin release by blocking dopamine receptors in the pituitary gland. Genetic factors play an important role in the development of antipsychotic induced HP [1,2]. Genes coding for dopamine receptors and transporters are considered to be responsible for HP in schizophrenia [3]. The present study aimed to investigate the role of polymorphisms of the dopamine receptors and transporters genes (DRD1, DRD2, SLC6A3) in the pathogenesis of antipsychotic-related HP in patients with schizophrenia. Methods: 431 Russian patients with schizophrenia were examined. The average age of patients was 42.1 ± 1.4 years. Evaluation of serum prolactin level was performed by ELISA using reagents set PRL Test System (USA). Genotyping was carried out on 17 polymorphic variants of the dopamine receptors and transporters genes DRD1 (rs4532, rs936461), DRD2 (rs4245147, rs6279, rs2734842) and SLC6A3 (rs3756450, rs2550956, rs6347, rs2617605, rs3863145, rs250686, rs464049, rs4975646, rs1048953, rs11133767, rs27048, rs40184). The SPSS software was used for statistical analysis. The Hardy-Weinberg equilibrium (HWE) of genotypic frequencies was tested by the chi-square test. Results: We studied the association between HP and a set of SNPs from DRD1, DRD2 receptor genes and neurotransmitter transporter SLC6A3 in patients from Siberia with a clinical diagnosis of schizophrenia who were treated with classical and/or atypical antipsychotic drugs. All patients with schizophrenia were divided into two groups: those with and without HP. Physiological normal results for the serum prolactin levels are less than 20 ng/ml in men, and less than 25 ng/ml in women. Statistically significant result was obtained for polymorphic variant rs2550956 of the gene SLC6A3 (χ2 = 9.992; p = 0.007), which suggests its involvement in the development of HP. The heterozygous genotype TC of rs2550956 was significantly less common in patients with elevated levels of prolactin and it presumably has protective properties (OR 0.54; 95% CI: 0.36–0.81). We did not find any statistically significant associations for other polymorphisms DRD1 (rs4532, rs936461), DRD2 (rs4245147, rs6279, rs2734842) and SLC6A3 (rs3756450, rs6347, rs2617605, rs3863145, rs250686, rs464049, rs4975646, rs1048953, rs11133767, rs27048, rs40184). The group of dopamine receptors is heterogeneous and only some of them participate in the formation of psychotic symptoms and, accordingly, in the antipsychotic action of neuroleptics. The effect of neuroleptics on other groups of dopamine receptors leads to the development of different side effects including extrapyramidal disorders [4], and their role is extremely low in the formation of the actual therapeutic response. Conclusion: Our results indicate that genetic variants of SLC6A3 may have functional consequences on the modulation of prolactin secretion. Neurotransmitter systems are involved in the mechanisms of action of antipsychotic drugs; therefore, a further search for genetic markers associated with the development of antipsychotic-related hyperprolactinemia in schizophrenic patients is needed. References [1] Ivanova, S.A., Osmanova, D.Z., Boiko, A.S., Pozhidaev, I.V., Freidin, M.B., Fedorenko, O.Y., Semke, A.V., Bokhan, N.A., Kornetova, E.G., Rakhmazova, L.D., Wilffert, B., Loonen, A.J., 2016. Prolactin gene polymorphism (-1149G/T) is associated with hyperprolactinemia in patients with schizophrenia treated with antipsychotics. Schizophrenia Research Oct 21, pii: S0920-9964 (16)30473-X. doi: 10.1016/j.schres.2016.10.029. [2] Ivanova, S.A., Osmanova, D.Z., Freidin, M.B., Fedorenko, O.Y., Boiko, A.S., Pozhidaev, I.V., Semke, A.V., Bokhan, N.A., Agarkov, A.A., Wilffert, B., Loonen, A.J., 2017. Identification of 5-hydroxytryptamine receptor gene polymorphisms modulating hyperprolactinaemia in antipsychotic drug-treated patients with schizophrenia. World J Biol Psychiatry 18 (3), 239–246. [3] Miura, I., Zhang, J.P., Hagi, K., Lencz, T., Kane, J.M., Yabe, H., Malhotra, A.K., Correll, C.U., 2016. Variants in the DRD2 locus and antipsychotic-related prolactin levels: A meta-analysis. Psychoneuroendocrinology 72, 1–10. [4] Al Hadithy, A.F.Y., Ivanova, S.A., Pechlivanoglou, P., Semke, A., Fedorenko, O., Kornetova, E., Ryadovaya, L., Brouwers, J.R.B.J., Wilffert, B., Bruggeman, R., Loonen, A.J.M., 2009. Tardive dyskinesia and DRD3, HTR2A and HTR2C gene polymorphisms in Russian psychiatric inpatients from Siberia. Progress in NeuroPsychopharmacology and Biological Psychiatry 33, 475–481. Keywords: Dopamine Genetics / Molecular genetics Schizophrenia: basi