| 1 | Neurosci. Lett. 2002 Mar 321: 165-8 |
|---|---|
| PMID | 11880198 |
| Title | Analysis of association between the Gln192Arg polymorphism of the paraoxonase gene and schizophrenia in humans. |
| Abstract | An increasing amount of evidence suggests a possible implication of oxidative stress in the pathophysiology of schizophrenia. Oxidized low-density lipoproteins (oxLDL) have been reported to be capable of eliciting neurocytotoxicity. On the other hand, paraoxonase (PON1), an arylesterase, plays a role in protection against oxidative modifications of LDL and is considered to be one of the antioxidant enzymes. Thus, we investigated the genetic association between a functional polymorphism (Gln192Arg) of the human PON1 gene and schizophrenia in 244 patients and 177 controls. No significant association between the polymorphism and schizophrenia was observed. In addition, our results revealed that there was no association between the genotypes of the polymorphism and any demographic characteristics of patients such as gender, age, age at onset, or current neuroleptic dosage. Our results suggest that the Gln192Arg polymorphism of the PON1 gene may not be involved in the susceptibility to schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 2 | Psychiatr. Genet. 2008 Dec 18: 289-94 |
| PMID | 19018234 |
| Title | Paraoxonase-1 55/192 genotypes in schizophrenic patients and their relatives in Turkish population. |
| Abstract | Oxidative stress and free radical-induced toxicity have been implicated in the pathophysiology of schizophrenia. In this study, we examined paraoxonase (PON1)-55/192 polymorphisms and PON1 activity in patients with schizophrenia, first-degree relatives of schizophrenic patients, and healthy controls. This study consisted of 292 healthy participants, 267 unrelated patients with schizophrenia and 311 first-degree relatives of schizophrenic patients. PON1 55 (rs 854560) and PON1 192 (rs 662) polymorphisms were performed by restriction fragment length polymorphism. The frequencies of the QQ and LL genotypes were significantly overpresented in controls compared with those of schizophrenic patients and their relatives. In contrast, the RR genotype was more prevalent in patients than their relatives and healthy controls. The frequencies of the LM and QR genotypes in relatives were higher than controls. Serum PON1 activities of controls were significantly higher when compared with both schizophrenic patients and their relatives. The RR and LL genotypes were associated with a significantly increased PON1 activity as compared with QR or QQ and MM or LM genotypes, respectively, in all groups. This is the first study that shows the association between PON1-55/192 polymorphisms and schizophrenia. Our data suggest that the subjects carrying R allele or RR genotype might be susceptible to schizophrenia and subjects with QQ or LL might be protected against schizophrenia. First-degree relatives of schizophrenic patients have higher heterozygote genotypes, suggesting that this group can shift either to patient or control group depending on their allele types and environmental factors. PON1 genetic variations are also associated with PON1 activities. Reduced PON1 activity in patients and their relatives might result from the combined effects of more than one polymorphic variant in PON1 or other genes and/or increased oxidative stress, supporting the hypothesis that reactive oxygen species-mediated cellular damage might contribute to the neuropathology of schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 3 | Psychiatr. Genet. 2008 Dec 18: 289-94 |
| PMID | 19018234 |
| Title | Paraoxonase-1 55/192 genotypes in schizophrenic patients and their relatives in Turkish population. |
| Abstract | Oxidative stress and free radical-induced toxicity have been implicated in the pathophysiology of schizophrenia. In this study, we examined paraoxonase (PON1)-55/192 polymorphisms and PON1 activity in patients with schizophrenia, first-degree relatives of schizophrenic patients, and healthy controls. This study consisted of 292 healthy participants, 267 unrelated patients with schizophrenia and 311 first-degree relatives of schizophrenic patients. PON1 55 (rs 854560) and PON1 192 (rs 662) polymorphisms were performed by restriction fragment length polymorphism. The frequencies of the QQ and LL genotypes were significantly overpresented in controls compared with those of schizophrenic patients and their relatives. In contrast, the RR genotype was more prevalent in patients than their relatives and healthy controls. The frequencies of the LM and QR genotypes in relatives were higher than controls. Serum PON1 activities of controls were significantly higher when compared with both schizophrenic patients and their relatives. The RR and LL genotypes were associated with a significantly increased PON1 activity as compared with QR or QQ and MM or LM genotypes, respectively, in all groups. This is the first study that shows the association between PON1-55/192 polymorphisms and schizophrenia. Our data suggest that the subjects carrying R allele or RR genotype might be susceptible to schizophrenia and subjects with QQ or LL might be protected against schizophrenia. First-degree relatives of schizophrenic patients have higher heterozygote genotypes, suggesting that this group can shift either to patient or control group depending on their allele types and environmental factors. PON1 genetic variations are also associated with PON1 activities. Reduced PON1 activity in patients and their relatives might result from the combined effects of more than one polymorphic variant in PON1 or other genes and/or increased oxidative stress, supporting the hypothesis that reactive oxygen species-mediated cellular damage might contribute to the neuropathology of schizophrenia. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 4 | Neuropsychiatr Dis Treat 2013 -1 9: 1545-52 |
| PMID | 24143103 |
| Title | Reduced serum paraoxonase 1 (PON1) activity in patients with schizophrenia treated with olanzapine but not quetiapine. |
| Abstract | Second generation antipsychotics (SGAs) are currently the most prescribed drugs in the treatment of schizophrenia. Despite their advantages, which include greater improvement in negative symptoms, cognitive function, prevention of deterioration, quality of life, and fewer extrapyramidal symptoms, the concern regarding metabolic abnormalities which might cause cardiovascular diseases during treatment with SGAs have been rising. Paraoxonase 1 (PON1) is an enzyme mostly located on high-density lipoprotein particles, and has been shown to protect or inhibit lipoprotein oxidation. Growing evidence suggests that PON1 plays a key role in the pathophysiology of atherosclerosis. In the present study, we measured serum PON1 activity and serum levels of total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in patients with schizophrenia, who had been treated with either olanzapine or quetiapine, and in healthy controls. Thirty five patients who had been treated with olanzapine, 29 patients who had been treated with quetiapine, and 32 age, sex, and smoking status-matched healthy control (HC) participants were enrolled. Serum PON1 activity and serum levels of TC, triglyceride, HDL-C, and LDL-C were measured. Serum PON1 activity in the olanzapine group was significantly lower than that of HC and quetiapine groups. Furthermore, serum levels of TC and LDL-C in the olanzapine group were significantly higher than those of quetiapine and HC groups. Interestingly, there was a positive correlation between PON1 activity and HDL-C levels in the olanzapine group. These findings suggest that serum PON1 activity in patients treated with olanzapine was lower than that of HC and quetiapine groups, and that PON1 may play a role in the metabolic side effects associated with olanzapine treatment. A further study to examine the relationship between serum PON1 activity and cardiovascular and metabolic side effects during treatment with SGAs will be of great interest. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 5 | Asian J Psychiatr 2014 Jun 9: 36-40 |
| PMID | 24813034 |
| Title | Paraoxonase 1 activity and lipid profile in schizophrenic patients. |
| Abstract | This study aimed to investigate the variations of paraoxonase 1 (PON1) activity and lipid profile in patients with schizophrenia and the association of this activity with the sociodemographic, clinical and therapeutical characteristics of this population. Our cross-sectional study included 140 schizophrenic patients and 119 control subjects aged respectively 37.3±10.4 and 41.4±10 years. PON1 activity was determined using Konelab 30? equipment (Thermo Electron Corporation). Plasma total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (c-HDL) and low-density lipoprotein cholesterol (c-LDL) concentrations were determined using Cobas 6000? (Roche Diagnostics), apolipoproteins (ApoA1, ApoB) and lipoprotein (a) (Lp(a)) were determined using Integra 400 plus (Roche Diagnostics). Compared to controls, patients had no significant decrease of PON1 activity and significantly lower ApoA1, c-HDL levels, and significantly higher levels of TG, ApoB, Lp(a) and TC/c-HDL and ApoB/ApoA1 ratios. Furthermore, PON1 activity was correlated with TG/c-HDL ratio. The lowest PON1 activity was noted in obese patients, in paranoid sub-type and in patients treated with combination of typical and atypical antipsychotics without significant difference. Moreover, it was associated with gender and cigarette smoking but not with alcohol consumption status. schizophrenic patients had a decrease in PON1 activity and perturbations in their lipid profiles that contribute to increase the risk of cardiovascular diseases. In addition, our results revealed that there was no association between the decrease of PON1 activity and any demographic or clinical characteristics. Therefore, such patients require specific care, particularly with regard to their lipid profile. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 6 | Asian J Psychiatr 2014 Jun 9: 36-40 |
| PMID | 24813034 |
| Title | Paraoxonase 1 activity and lipid profile in schizophrenic patients. |
| Abstract | This study aimed to investigate the variations of paraoxonase 1 (PON1) activity and lipid profile in patients with schizophrenia and the association of this activity with the sociodemographic, clinical and therapeutical characteristics of this population. Our cross-sectional study included 140 schizophrenic patients and 119 control subjects aged respectively 37.3±10.4 and 41.4±10 years. PON1 activity was determined using Konelab 30? equipment (Thermo Electron Corporation). Plasma total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (c-HDL) and low-density lipoprotein cholesterol (c-LDL) concentrations were determined using Cobas 6000? (Roche Diagnostics), apolipoproteins (ApoA1, ApoB) and lipoprotein (a) (Lp(a)) were determined using Integra 400 plus (Roche Diagnostics). Compared to controls, patients had no significant decrease of PON1 activity and significantly lower ApoA1, c-HDL levels, and significantly higher levels of TG, ApoB, Lp(a) and TC/c-HDL and ApoB/ApoA1 ratios. Furthermore, PON1 activity was correlated with TG/c-HDL ratio. The lowest PON1 activity was noted in obese patients, in paranoid sub-type and in patients treated with combination of typical and atypical antipsychotics without significant difference. Moreover, it was associated with gender and cigarette smoking but not with alcohol consumption status. schizophrenic patients had a decrease in PON1 activity and perturbations in their lipid profiles that contribute to increase the risk of cardiovascular diseases. In addition, our results revealed that there was no association between the decrease of PON1 activity and any demographic or clinical characteristics. Therefore, such patients require specific care, particularly with regard to their lipid profile. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 7 | Adv Gerontol 2015 -1 28: 228-47 |
| PMID | 26856084 |
| Title | GENETICS OF HUMAN AGE RELATED DISORDERS. |
| Abstract | Aging is an inevitable biological phenomenon. The incidence of age related disorders (ARDs) such as cardiovascular diseases, cancer, arthritis, dementia, osteoporosis, diabetes, neurodegenerative diseases increase rapidly with aging. ARDs are becoming a key social and economic trouble for the world's elderly population (above 60 years), which is expected to reach 2 billion by 2050. Advancement in understanding of genetic associations, particularly through genome wide association studies (GWAS), has revealed a substantial contribution of genes to human aging and ARDs. In this review, we have focused on the recent understanding of the extent to which genetic predisposition may influence the aging process. Further analysis of the genetic association studies through pathway analysis several genes associated with multiple ARDs have been highlighted such as apolipoprotein E (APOE), brain-derived neurotrophic factor (BDNF), cadherin 13 (CDH13), CDK5 regulatory subunit associated protein 1 (CDKAL-1), methylenetetrahydrofolate reductase (MTHFR), disrupted in schizophrenia 1 (DISC1), nitric oxide synthase 3 (NOS3), paraoxonase 1 (PON1), indicating that these genes could play a pivotal role in ARD causation. These genes were found to be significantly enriched in Jak-STAT signalling pathway, asthma and allograft rejection. Further, interleukin-6 (IL-6), insulin (INS), vascular endothelial growth factor A (VEGFA), estrogen receptor1 (ESR1), transforming growth factor, beta 1(TGFB1) and calmodulin 1 (CALM1) were found to be highly interconnected in network analysis. We believe that extensive research on the presence of common genetic variants among various ARDs may facilitate scientists to understand the biology behind ARDs causation. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 8 | J Psychiatr Res 2015 Sep 68: 210-6 |
| PMID | 26228421 |
| Title | Oxidative stress in drug naïve first episode psychosis and antioxidant effects of risperidone. |
| Abstract | schizophrenia is accompanied by increased lipid peroxidation and nitric oxide (NO) levels and by lowered antioxidant levels. However, the effect of antipsychotic agents on these processes remains unclear. The objective of this study is to determine the oxidative stress (OS) status in drug naïve first-episode psychotic patients (FEP) compared to healthy controls and to delineate the effects of risperidone on these biomarkers. 51 drug naive FEP patients and 61 healthy controls were enrolled; FEP patients were reassessed 11 weeks after risperidone treatment. Three OS biomarkers, i.e. lipid hydroperoxides - LOOH, NO metabolites - NOx, and advanced oxidation protein products - AOPP, and two antioxidant biomarkers, i.e. total radical-trapping antioxidant parameter - TRAP, and paraoxonase 1 - PON1, were measured. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for schizophrenia (CDSS) were used to measure symptoms severity. Significantly lower PON1 activity and increased TRAP values were found in FEP patients. There were no significant associations between any of the OS/antioxidant biomarkers and clinical data. Risperidone treatment significantly increased PON1 activity and decreased LOOH levels. These effects of risperidone were not significantly associated with the clinical response and risperidone dosage. Changes in antioxidant profile, but not in lipid or protein oxidation or increased NO production, were found in drug-naive FEP. Risperidone may have antioxidant effects by lowering lipid peroxidation and increasing the antioxidant defenses against lipid peroxidation related to PON1. None of the biomarkers predicted treatment outcome. |
| SCZ Keywords | schizophrenia, schizophrenic |
| 9 | Schizophr. Res. 2015 Aug 166: 225-30 |
| PMID | 26123170 |
| Title | Lowered paraoxonase 1 (PON1) activity is associated with increased cytokine levels in drug naïve first episode psychosis. |
| Abstract | Activated immune-inflammatory pathways play an important role in the pathophysiology of schizophrenia. Paraoxonase 1 (PON1) activity is inversely associated with inflammatory responses in numerous clinical conditions. The aims of this study were to delineate serum arylesterase PON1 activity in drug-naïve first episode psychosis (FEP) patients and a healthy control group, and to assess whether there are inverse relationships between PON1 activity and cytokine levels. A total of 51 drug-naïve FEP patients and 61 healthy controls were enrolled in this study. Levels of interleukin (IL)-4, IL-10, IL-6, tumor necrosis factor (TNF)-? and activity of PON1 were quantified. Compared to healthy controls, FEP patients showed lower serum PON1 activity and higher levels of IL-4, IL-10 and TNF-?. A significant inverse relationship between PON1 activity and IL-4, IL-6 and IL-10 levels was detected, but not for TNF-?. Subjects with very low PON1 activity (25th quartile) presented significantly higher levels of IL-6, IL-10 and IL-4 than those with higher PON1 activity (75th quartile). The present study provides evidence that FEP is characterized by an inverse relationship between lowered activity of the anti-inflammatory/antioxidant enzyme PON1 and increased cytokine levels, including IL-6, IL-4 and IL-10. It is hypothesized that lowered PON1 activity may play a role in the immune-inflammatory response that accompanies FEP and that increased cytokine levels may further modulate PON1 activity. |
| SCZ Keywords | schizophrenia, schizophrenic |