Antoni Florkowski

Lipid peroxidation and antioxidant protection in patients during acute depressive episodes and in remission after fluoxetine treatment

Increasing numbers of studies indicate that free radicals and their derivatives play a role in some neuropsychiatric disorders, such as depression. The aim of this study was to investigate the activities of antioxidant enzymes, lipid peroxidation and total antioxidant status (TAS) in patients suffering from major depressive disorder (MDD) as compared to healthy controls. Specifically, we wanted to estimate how fluoxetine influences antioxidant defense and lipid peroxidation. Fifty MDD patients and thirty healthy controls participated in the study. Antioxidant enzyme activities and lipid peroxidation levels were measured in erythrocytes, while TAS was measured in plasma. All measurements were taken during an acute depressive episode and then again during depression remission after a three-month fluoxetine treatment. During acute depressive episodes, patients had significantly higher activity levels of antioxidant enzymes, such as copper-zinc superoxide dismutase (SOD1) and catalase (CAT), as compared to healthy controls. Concentrations of malondialdehyde (MDA) were also significantly higher during depressive episodes. Activity levels of glutathione peroxidase (GPx) did not differ significantly between depressed patients and healthy control subjects. Moreover, the plasma total antioxidant status of the depressed patients was decreased in comparison to control subjects. After three months of fluoxetine treatment, the above parameters did not change significantly. Major depressive disorder is accompanied by disturbances in the balance between pro- and anti-oxidative processes; however, these disturbances do not improve in patients in remission after three months of fluoxetine therapy.

Single‐nucleotide polymorphisms and mRNA expression for melatonin synthesis rate‐limiting enzyme in recurrent depressive disorder

Abstract:  Depressive disorder (DD) is characterised by disturbances in blood melatonin concentration. It is well known that melatonin is involved in the control of circadian rhythms, sleep included. The use of melatonin and its analogues has been found to be effective in depression therapy. Melatonin synthesis is a multistage process, where the last stage is catalysed by acetylserotonin methyltransferase (ASMT), the reported rate‐limiting melatonin synthesis enzyme. Taking into account the significance of genetic factors in depression development, the gene for ASMT may become an interesting focus for studies in patients with recurrent DD. The goal of the study was to evaluate two single‐nucleotide polymorphisms (SNPs) (rs4446909; rs5989681) of the ASMT gene, as well as mRNA expression for ASMT in recurrent DD‐affected patients. We genotyped two polymorphisms in a group of 181 recurrent DD patients and in 149 control subjects. The study was performed using the polymerase chain reaction/restriction fragment length polymorphism method. The distribution of genotypes in both studied SNPs in the ASMT gene differed significantly between DD and healthy subjects. The presence of AA genotype of rs4446909 polymorphism and of GG genotype of rs5989681 polymorphism was associated with lower risk for having recurrent DD. In turn, patients with depression were characterised by reduced mRNA expression for ASMT. In addition, ASMT transcript level in both recurrent DD patients and in healthy subjects depended significantly on genotype distributions in both polymorphisms. In conclusion, our results suggest the ASMT gene as a susceptibility gene for recurrent DD.

Association between inducible and neuronal nitric oxide synthase polymorphisms and recurrent depressive disorder

BACKGROUND Major depression is characterised by increased nitric oxide (NO) levels. Inhibition of the NO synthesizing enzymes, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS), results in antidepressant-like effects, whereas the expression of iNOS and nNOS is increased in depression. Recent studies have indicated that NOS participates in the mechanisms of antidepressants. The aim of this study was to examine whether a single nucleotide polymorphism (SNP) present in the genes encoding iNOS and nNOS can contribute to the risk of developing recurrent depressive disorder (rDD). METHODS The study was carried out in a group of 181 depressive patients and 149 control subjects of Polish origin. SNPs were assessed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses. RESULTS The genotype distributions of the polymorphisms in exon 22 of the NOS2A gene and in exon 29 of the nNOS gene were significantly different between rDD patients and controls. The results showed that the G/A SNP of the gene encoding iNOS was associated with an increased susceptibility to rDD, whereas A/A homozygous carriers had a decreased risk of developing rDD. There was also a significant association between the C/T SNP of the gene encoding nNOS; the presence of the CC homozygous genotype decreased the risk of rDD, whereas the T allele and T/T homozygous genotype increased the vulnerability to rDD. CONCLUSIONS Our results suggest that polymorphisms in the iNOS and nNOS genes confer an increased susceptibility or resistance to rDD. Future research should examine genetic variants and their associations to the expression of NOSs and NO level in depressive patients.

Analysis of two polymorphisms of the manganese superoxide dismutase gene (Ile-58Thr and Ala-9Val) in patients with recurrent depressive disorder

Reactive oxygen species (ROS) may contribute to the pathogenesis of depressive disorder (DD). Functional genetic polymorphisms of manganese superoxide dismutase (MnSOD) are candidates for DD susceptibility. The study examined the relationship between MnSOD gene polymorphisms (Ala-9Val, Ile-58Thr) and DD in the Polish population. The association study was conducted in a case-control design in DD patients (n=149) and healthy controls (CG; n=149) by genotyping. Assessment of Ala-9Val genotype distribution and disease odds ratio demonstrated a statistically significant difference between the compared groups only in the female subgroup. The obtained results suggest a role of the MnSOD polymorphism in the development and course of depression.

Functional polymorphism of cyclooxygenase-2 gene (G-765C) in depressive patients.

Background: Depressive disorder (DD) is characterized by an inflammatory process and oxidative stress. Cyclooxygenase-2 (COX-2), the expression of which increases in depression, is an enzyme involved in inflammation and free radical processes. The aim of our study was to assess the correlation between single nucleotide polymorphism G–765C of the COX-2 gene and recurrent DD. Methods: The study was carried out in a group of 181 patients treated for recurrent DD, and in 149 healthy subjects of the control group (CG). Polymerase chain reaction/restriction fragment length polymorphism was used for genotyping. Results: A statistically significant difference in genotype distribution was observed as a result of the comparison between the CG and the patients with DD. We demonstrated that the presence of the –765G allele in the COX-2 gene increased 2.1-fold the risk of DD development, whereas the presence of a homozygote (G–765G) in the analyzed gene increased the risk of DD development 2.5-fold. Conclusion: According to the obtained results, it may be proposed with some caution that the presence of both the –765G allele and the G–765G genotype in the COX-2 gene may confer a susceptibility to an increased risk of recurrent DD in the Polish population.

An inducible nitric oxide synthase polymorphism is associated with the risk of recurrent depressive disorder

Evidence indicates that depressive disorder is a heterogenic disease, and oxidative stress, inflammation and impairment of neurogenesis play a role in its aetiology. Moreover, there are data suggesting that genetic factors affect the development of depression. Nitric oxide (NO) is a biological molecule with both a beneficial and a detrimental role in brain. One of the three enzymes generating NO is inducible nitric oxide synthase (iNOS). Recent studies have shown that depressed patients are characterised by excessive NO production. In addition, iNOS inhibitors are effective in depression treatment. This study investigated the importance of a functional single nucleotide polymorphism (SNP), -1026C/A, located in the promoter region of the human NOS2A gene, for the risk of recurrent depressive disorder (RDD) vulnerability. The study was carried out in a group of 181 patients with RDD and 149 ethnically matched controls. Genotyping was performed by direct sequencing of the polymerase chain reaction (PCR) products. The genotype distribution of the -1026C/A polymorphism between depressed patients and healthy controls was significantly different. Individuals who were homozygous for the CC genotype exhibited an increased risk of developing RDD. In conclusion we cautiously conclude that polymorphism in the NOS2A gene promoter may play a role in the background of RDD.

Single nucleotide polymorphisms and mRNA expression for melatonin MT2 receptor in depression

Polymorphisms (rs 4753426 and rs 794837) and expression of the melatonin MT(2) receptor gene were evaluated in 181 patients with recurrent depressive disorder (rDD) and 149 healthy subjects of Polish origin. We found an increased risk for rDD in patients with the C allele and a decreased risk in patients with the T allele (rs4753426). Patients with the AT heterozygote (rs794837) had an increased mRNA level. The significance of the MT(2) receptor gene and the risk of rDD are suggested.

Auditory-verbal declarative and operating memory among patients suffering from depressive disorders - preliminary study.

PURPOSE Dysfunctions of auditory-verbal declarative and working memory are observed in patients with depressive disorders (DD). The authors wanted to see, whether antidepressive therapy improved the efficiency of cognitive processes among patients suffering from DD and determine possible associations between auditory-verbal declarative and working memory performance, evaluated before treatment vs. remission degree after treatment. MATERIAL AND METHODS The study was carried out in 87 subjects, patients with depressive disorders (n=30, DD) and healthy subjects (n=57, CG, control group). The AVLT (Auditory Verbal Learning Test) and the Stroop Test were used. RESULTS CG obtained higher results vs. DD-I (the evaluation started on the therapy onset) in the Stroop Test-RCNb (Reading Colour Names in Black)/time, NCWd (Naming Colour of Word - Different)/time, NCWd/errors, AVLT: the number of words after 30 minutes. CG demonstrated higher results than DD-II (following eight weeks of pharmacological treatment) in RCNb/time, NCWd/time, AVLT: the number of words in the first trial, the number of words after 30 minutes. Compared to DD-I, DD-II achieved better results in NCWd/errors. No statistically significant differences were observed in both tests between the patients with remission and without remission. Statistical analysis revealed the lack of significant dependences among HDRS after treatment and cognitive functions before treatment. CONCLUSIONS Depressive disorders are associated with deteriorated efficiency of auditory-verbal declarative and working memory. No improvement was observed in the efficiency of auditory-verbal declarative or working memory after 8-week therapy. The performance level of cognitive processes before pharmacotherapy has no effect on the intensity of depression symptoms after therapy.

Normalization of the Verbal Fluency Test on the basis of results for healthy subjects, patients with schizophrenia, patients with organic lesions of the chronic nervous system and patients with type 1 and 2 diabetes

Introduction Verbal fluency is the ability to form and express words compatible with required criteria. Verbal fluency is necessary for optimal communication and for normal social and occupational functioning. The Verbal Fluency Test is a good indicator of frontal lobe dysfunction, particularly of the left frontal cortex. Material and methods The aim of the study was to compare verbal fluency in healthy subjects (n = 50), patients with paranoid schizophrenia (n = 36), patients with organic lesions of the central nervous system (CNS) (n = 33), and patients with diabetes (n = 62) – type 1 diabetes (n = 31) and type 2 diabetes (n = 31). Results Healthy subjects and patients with diabetes achieved the highest results in all categories of the Verbal Fluency Test. Patients with paranoid schizophrenia achieved significantly lower results. Sten norms of the Verbal Fluency Test were developed for the general population. Using these norms it was found that subjects with schizophrenia or with organic lesions of the CNS had very poor results more often and very high results less frequently compared to healthy subjects and also to patients with diabetes. Conclusions This observation is consistent with the neurodevelopmental hypothesis of schizophrenia, in which cognitive functions of the frontal lobe (e.g. verbal fluency) play a major role in the psychopathological picture. We have also demonstrated that in patients with type 1 and 2 diabetes verbal fluency is comparable with healthy subjects.

Functional polymorphism of the myeloperoxidase gene (G-463A) in depressive patients

Gałecki P, Florkowski A, Bobińska K, Śmigielski J, Bieńkiewicz M, Szemraj J. Functional polymorphism of the myeloperoxidase gene (G-463A) in depressive patients. Objective: Myeloperoxidase (MPO) is an enzyme involved in the production of hypochloric acid as well as other reactive oxygen species. This enzyme plays a significant role in inflammatory processes. In view of the observed associations between depression and such inflammatory processes, as well as of the reports that confirm the presence of oxidative stress in depression, this study was designed to assess the correlation, if any, between the single nucleotide polymorphism G-463A of the MPO gene and the risk of recurrent depressive disorders (DD). Methods: The study was carried out in a group of 149 patients with recurrent DD and 149 healthy control subjects. Genotyping was performed by PCR/restriction fragment length polymorphism. Results: A comparison between healthy controls and depressive patients showed a statistically significant difference in genotype distribution and allele frequency in the studied groups. Genotype distribution and allele frequency did not correlate with clinical variables of the patients. Conclusion: The obtained results of the study allow us to draw a cautious conclusion about the role of the analysed G-463A MPO polymorphism in recurrent DD development, which, however, requires eventual confirmation in further studies.