Paeoniflorin ameliorates chronic stress-induced depression-like behavior in mice model by affecting ERK1/2 pathway

Depression is a mental and emotional disorder that has made an opening great burden to the society. Paeoniflorin showed remarkable antidepressant-like effects in multiple animal models with depressive disorders. However, the molecule of paeoniflorin on depression is less studied. This study aims to explore the effect and the molecular mechanism of paeoniflorin on depression in a chronic restraint stress (CRS) mice model. CRS model of C57BL/6 J mice was set up. Sucrose preference test (SPT), tail suspension test (TST), open field test (OFT) and forced swimming test (FST) were used to assess depression symptoms. Immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting were implemented to detect the expression changes of the proteins involved in extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. Results showed that paeoniflorin treatment decreased the degree of depression in the CRS mice. Further analysis showed that the expression of ERK1/2 proteins was significantly downregulated, while paeoniflorin could elevate the expression of ERK1/2 proteins in CRS mice. Finally, it showed that inhibiting signaling ERK1/2 pathway could aggravate the depressive behavior when treatment with ERK-specific inhibitor U0126, while the condition could be partially relieved when treated with paeoniflorin. In conclusion, the present study demonstrated that paeoniflorin attenuated chronic stress-induced depression-like behavior in mice by affecting the ERK1/2 pathway. These findings provided the basis for the molecular mechanism of paeoniflorin on the effect of depression, which support paeoniflorin might act as an important drug in the treatment of depression.

Botanical Drug Puerarin Ameliorates Liposaccharide-Induced Depressive Behaviors in Mice via Inhibiting RagA/mTOR/p70S6K Pathways

BACKGROUND

The depressive symptom hallmarks the progression of the neurodegenerative diseases, especially Alzheimer's disease. Bacterial infection is related to inflammation and depression. The present project thereby examined whether botanical drug puerarin could attenuate liposaccharide- (LPS-) induced depressive behaviors in mice.

METHODS

Adult male C57BL/6N mice were sequentially treated with LPS and puerarin and evaluated for the depressive behaviors by tail suspension test and forced swim test. The brain tissues were profiled for the molecular targets of puerarin by next-generation RNA sequencing technique. Candidate targets were further verified in LPS-treated mice, neural stem cells, and highly differentiated PC12 cell line.

RESULTS

Puerarin ameliorated LPS-induced depression in the mice. RNA sequencing profiles revealed that puerarin altered the expression of 16 genes while markedly downregulated Ras-related GTP-binding protein A (RagA) in LPS-treated mice. The effect of puerarin on RagA expression was confirmed by immunostaining, Western blot, and quantitative real-time PCR (qRT-PCR). Biochemical studies showed that puerarin inhibited RagA/mTOR/p70S6K pathway, attenuated the accumulation of mTORC1 in close proximity to lysosome, and reduced the production of proinflammatory cytokines.

CONCLUSIONS

Botanical drug puerarin attenuated inflammation and depressive behaviors in LPS-challenged mice by inhibiting RagA/mTOR/p70S6K pathways. Puerarin may be a lead compound for the new antidepressant drugs.

Cognitive effects of the GSK-3 inhibitor "lithium" in LPS/chronic mild stress rat model of depression: Hippocampal and cortical neuroinflammation and tauopathy

Low-dose repeated lipopolysaccharide pre-challenge followed by chronic mild stress (LPS/CMS) protocol has been introduced as a rodent model of depression combining the roles of immune activation and chronic psychological stress. However, the impact of this paradigm on cognitive functioning has not been investigated hitherto.

METHODS

This study evaluated LPS/CMS-induced cognitive effects and the role of glycogen synthase kinase-3β (GSK-3β) activation with subsequent neuroinflammation and pathological tau deposition in the pathogenesis of these effects using lithium (Li) as a tool for GSK-3 inhibition.

RESULTS

LPS pre-challenge reduced CMS-induced neuroinflammation, depressive-like behavior and cognitive inflexibility. It also improved spatial learning but increased GSK-3β expression and exaggerated hyperphosphorylated tau accumulation in hippocampus and prefrontal cortex. Li ameliorated CMS and LPS/CMS-induced depressive and cognitive deficits, reduced GSK-3β over-expression and tau hyperphosphorylation, impeded neuroinflammation and enhanced neuronal survival.

CONCLUSION

This study draws attention to LPS/CMS-triggered cognitive changes and highlights how prior low-dose immune challenge could develop an adaptive capacity to buffer inflammatory damage and maintain the cognitive abilities necessary to withstand threats. This work also underscores the favorable effect of Li (as a GSK-3β inhibitor) in impeding exaggerated tauopathy and neuroinflammation, rescuing neuronal survival and preserving cognitive functions. Yet, further in-depth studies utilizing different low-dose LPS challenge schedules are needed to elucidate the complex interactions between immune activation and chronic stress exposure.

The Forebrain-Specific Overexpression of Acid Sphingomyelinase Induces Depressive-Like Symptoms in Mice

Human and murine studies identified the lysosomal enzyme acid sphingomyelinase (ASM) as a target for antidepressant therapy and revealed its role in the pathophysiology of major depression. In this study, we generated a mouse model with overexpression of Asm (Asm-tg^fb) that is restricted to the forebrain to rule out any systemic effects of Asm overexpression on depressive-like symptoms. The increase in Asm activity was higher in male Asm-tg^fb mice than in female Asm-tg^fb mice due to the breeding strategy, which allows for the generation of wild-type littermates as appropriate controls. Asm overexpression in the forebrain of male mice resulted in a depressive-like phenotype, whereas in female mice, Asm overexpression resulted in a social anxiogenic-like phenotype. Ceramides in male Asm-tg^fb mice were elevated specifically in the dorsal hippocampus. mRNA expression analyses indicated that the increase in Asm activity affected other ceramide-generating pathways, which might help to balance ceramide levels in cortical brain regions. This forebrain-specific mouse model offers a novel tool for dissecting the molecular mechanisms that play a role in the pathophysiology of major depression.

Anxiety and Depression Are Related to Higher Activity of Sphingolipid Metabolizing Enzymes in the Rat Brain

Changes in sphingolipid metabolism have been suggested to contribute to the pathophysiology of major depression. In this study, we investigated the activity of acid and neutral sphingomyelinases (ASM, NSM) and ceramidases (AC, NC), respectively, in twelve brain regions of female rats selectively bred for high (HAB) versus low (LAB) anxiety-like behavior. Concomitant with their highly anxious and depressive-like phenotype, HAB rats showed increased activity of ASM and NSM as well as of AC and NC in multiple brain regions associated with anxiety- and depressive-like behavior, including the lateral septum, hypothalamus, ventral hippocampus, ventral and dorsal mesencephalon. Strong correlations between anxiety-like behavior and ASM activity were found in female HAB rats in the amygdala, ventral hippocampus and dorsal mesencephalon, whereas NSM activity correlated with anxiety levels in the dorsal mesencephalon. These results provide novel information about the sphingolipid metabolism, especially about the sphingomyelinases and ceramidases, in major depression and comorbid anxiety.

[Change of hepatic drug metabolism enzymes in rat depression model with kidney-yang deficiency]

This study was designed to explore the impact of depression on kidney-yang deficiency in rats. Rats were repeatedly injected with hydrocortisone for 21 days to establish the depression model with kidneyyang deficiency. Tolbutamide, chlorzoxazone, theophylline, midazolam, omeprazole and dextromethorphan were used as substrates of CYP2C6, CYP2E1, CYP1A2, CYP3A2, CYP2D1, and CYP2D2 to test the depression impact on drug metabolism. Plasma concentrations of six CYP450 were determined by LC-MS/MS and used as pharmacokinetic parameters. Consequently, metabolism of theophylline, chlorzoxazone and tolbutamide were accelerated significantly in the model relative to the control (P < 0.01), but dextromethorphan, omeprazole and midazolam did not exhibit a significant difference. The present study suggests that depression with kidneyyang deficiency had a strong induction of CYP2E1 and moderate induction of CYP1A2, CYP2C6 in the rat model.

A Model Based Cost-Effectiveness Analysis of Routine Genotyping for CYP2D6 among Older, Depressed Inpatients Starting Nortriptyline Pharmacotherapy

OBJECTIVE

Genotyping for CYP2D6 has the potential to predict differences in metabolism of nortriptyline. This information could optimize pharmacotherapy. We determined the costs and effects of routine genotyping for old aged Dutch depressed inpatients.

METHODS

With a decision-tree, we modelled the first 12 weeks of nortriptyline therapy. Direct costs of genotyping, hospitalization, therapeutic drug monitoring and drugs were included. Based on genotype, patients could be correctly, sub-, or supratherapeutically dosed. Improvement from sub- or supratherapeutically dosed patients to correctly dosed patients was simulated, assuming that genotyping would prevent under- or overdosing of patients. In the base case, this improvement was assumed to be 35%. A probabilistic sensitivity analysis (PSA) was performed to determine uncertainty around the incremental cost-effectiveness ratio (ICER).

RESULTS

In the base case analysis, costs for genotyping were assumed €200 per test with a corresponding ICER at €1 333 000 per QALY. To reach a €50 000 per QALY cut-off, genotyping costs should be decreased towards €40 per test. At genotyping test costs < €35 per test, genotyping was dominant. At test costs of €17 per test there was a 95% probability that genotyping was cost-effective at €50 000 per QALY.

CONCLUSIONS

CYP2D6 genotyping was not cost-effective at current genotyping costs at a €50 000 per QALY threshold, however at test costs below €40, genotyping could be costs-effective.

Effect of Coffee in Lipopolysaccharide-Induced Indoleamine 2,3-Dioxygenase Activation and Depressive-like Behavior in Mice

Research has identified a potential inverse correlation between coffee consumption and the risk of depression. The aim of this study was to investigate the effects of caffeinated coffee on lipopolysaccharide-induced depressive-like behaviors and inflammatory biomarkers in an in vivo model of depression in a C57BL/6J mouse model. The behavioral studies showed that caffeinated coffee decreased immobility time in both the tail suspension test (caffeinated coffee 56.60 ± 9.17; p < 0.0001) and the forced swimming test (caffeinated coffee 28.80 ± 5.93; p < 0.0001), suggesting antidepressant-like activity. The effects of caffeinated coffee on the inflammatory biomarkers associated with depression supported the results observed in the behavioral studies. Statistically significant decreases in indoleamine 2,3-dioxygenase activity (p < 0.001) and the neopterin/biopterin ratio (p < 0.001) were observed in animals pretreated with caffeinated coffee 24 h post-lipopolysaccharide exposure in comparison to the lipopolysaccharide control group. In conclusion, this study has provided evidence to suggest that caffeinated coffee has antidepressant-like activities; however, further studies are required to fully investigate these effects.

Role of Acid Sphingomyelinase in the Regulation of Social Behavior and Memory

Major depressive disorder is often associated with deficits in social and cognitive functioning. Mice transgenic for acid sphingomyelinase (t-ASM) were previously shown to have a depressive-like phenotype, which could be normalized by antidepressant treatment. Here, we investigated whether t-ASM mice show deficits in social behavior and memory performance, and whether these possible deficits might be normalized by amitriptyline treatment. Our results revealed that ASM overexpression altered the behavior of mice in a sex-dependent manner. As such, t-ASM female, but not male, mice showed an impaired social preference and a depressive- and anxiogenic-like phenotype, which could be normalized by amitriptyline treatment. Both male and female t-ASM mice showed unaltered preference for social novelty, novel object recognition, and social and object discrimination abilities. Amitriptyline treatment impaired novel object recognition and object discrimination abilities in female, but not in male, wild-type mice, while female t-ASM mice showed unaltered novel object recognition and object discrimination abilities. This study suggests that female t-ASM mice represent a model of depression with comorbid anxiety and social deficits, without memory impairments. It further suggests that ASM overexpression has a protective role against the detrimental effects of amitriptyline on female, but not on male, non-social (object) memory.

Type 2 Deiodinase Disruption in Astrocytes Results in Anxiety-Depressive-Like Behavior in Male Mice

Millions of levothyroxine-treated hypothyroid patients complain of impaired cognition despite normal TSH serum levels. This could reflect abnormalities in the type 2 deiodinase (D2)-mediated T4-to-T3 conversion, given their much greater dependence on the D2 pathway for T3 production. T3 normally reaches the brain directly from the circulation or is produced locally by D2 in astrocytes. Here we report that mice with astrocyte-specific Dio2 inactivation (Astro-D2KO) have normal serum T3 but exhibit anxiety-depression-like behavior as found in open field and elevated plus maze studies and when tested for depression using the tail-suspension and the forced-swimming tests. Remarkably, 4 weeks of daily treadmill exercise sessions eliminated this phenotype. Microarray gene expression profiling of the Astro-D2KO hippocampi identified an enrichment of three gene sets related to inflammation and impoverishment of three gene sets related to mitochondrial function and response to oxidative stress. Despite normal neurogenesis, the Astro-D2KO hippocampi exhibited decreased expression of four of six known to be positively regulated genes by T3, ie, Mbp (∼43%), Mag (∼34%), Hr (∼49%), and Aldh1a1 (∼61%) and increased expression of 3 of 12 genes negatively regulated by T3, ie, Dgkg (∼17%), Syce2 (∼26%), and Col6a1 (∼3-fold) by quantitative real-time PCR. Notably, in Astro-D2KO animals, there was also a reduction in mRNA levels of genes known to be affected in classical animal models of depression, ie, Bdnf (∼18%), Ntf3 (∼43%), Nmdar (∼26%), and GR (∼20%), which were also normalized by daily exercise sessions. These findings suggest that defects in Dio2 expression in the brain could result in mood and behavioral disorders.

[Effect of Acupuncture Intervention on c-jun N-terminal Kinase Signaling in the Hippocampus in Rats with Forced Swimming Stress]

OBJECTIVE

To observe the effect of acupuncture on c-jun N-terminal Kinase (JNK) signaling in the hippocampus in rats with forced-swimming stress, so as to reveal its underlying mechanism in relieving depression-like motor response.

METHODS

Forty-eight Sprague-Dawley rats were randomly divided into 8 groups as control, control + JNK inhibitor (SP 600125) , model, model + SP 600125, acupuncture, acupuncture + SP 600125, Fluoxetine (an anti-depressant) , and Fluoxetine + SP 600125 (n = 6 in each group). The depression-like behavior (immobility) model was established by forcing the rat to swim in a glass-cylinder and solitary raise. Acupuncture stimulation was applied to "Baihui" (GV-20) and "Yintang" (GV 29) for 20 min before forced swimming and once again 24 h later.. The rats of the Fluoxetine and Fluoxetine+ SP 600125 groups were treated by intragastric administration of fluoxetine 10 mL (1.8 mg)/kg before forced swimming and once again 24 h thereafter. The rats of the model + SP 600125 and acupuncture + SP 600125 groups were treated by intraperitoneal injection of SP 600125 (10 mg/kg) 90 min before forced swimming and 30 min before acupuncture intervention, respectively. The immobility duration of rats in the water glass-cylinder was used to assess their depression-like behavior response. The expression levels of protein kinase kinase 4 (MKK 4), MKK 7, JNK, and phosphorylated JNK (p-JNK) in the hippocampus were detected by Western blot.

RESULTS

Compared to the control group, the duration of immobility, and the expression levels of hippocampal MKK 4, MKK 7, and p-JNK proteins were significantly increased in the model group (P < 0.01). While in comparison with the model group, the duration of immobility in the model + SP 600125, acupuncture, acupuncture + SP 600125, Fluoxetine and Fluoxetine + SP 600125 groups, the expression levels of hippocampal MKK 4 and MKK 7 proteins in the Fluoxetine + SP 600125 group, and those of p-JNK protein in the acupuncture, acupuncture + SP 600125, model + SP 600125, Fluoxetine and Fluoxetine + SP 600125 groups were considerably decreased (P < 0.05, P < 0.01). No significant differences were found between the control and control + SP 600125 groups and among the model + SP 600125, acupuncture, acupuncture + SP 600125, Fluoxetine and Fluoxetine + SP 600125 groups in the duration of immobility (P > 0.05), and in the expression level of p-JNK protein (P > 0.05). No significant changes were found in the expression levels of JNK among the 8 groups (P > 0.05).

CONCLUSION

Acupuncture stimulation of GV 20 and GV 29 is effective in relieving depression-like motor response in forced-swimming stress rats, which may be closely associated with its effects in down-regulating the expression of hippocampal p-JNK protein.

Primary phospholipase C and brain disorders

In the brain, the primary phospholipase C (PLC) proteins, PLCβ, and PLCγ, are activated primarily by neurotransmitters, neurotrophic factors, and hormones through G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs). Among the primary PLC isozymes, PLCβ1, PLCβ4, and PLCγ1 are highly expressed and differentially distributed, suggesting a specific role for each PLC subtype in different regions of the brain. Primary PLCs control neuronal activity, which is important for synapse function and development. In addition, dysregulation of primary PLC signaling is linked to several brain disorders including epilepsy, schizophrenia, bipolar disorder, Huntington's disease, depression and Alzheimer's disease. In this review, we included current knowledge regarding the roles of primary PLC isozymes in brain disorders.

Elevated Salivary Alpha-Amylase Level, Association Between Depression and Disease Activity, and Stress as a Predictor of Disease Flare in Systemic Lupus Erythematosus: A Prospective Case-Control Study

Psychological stress has been shown to trigger systemic lupus erythematosus (SLE). However, objective evidence of symptom aggravation due to mental stress is difficult to identify. We aimed to investigate the relationship between SLE disease activity and mental stress, and the usefulness of saliva as an assessment index for stress in patients with SLE.We prospectively assessed the salivary stress hormone and disease-related biomarkers, and questionnaire data regarding stress and depression in 100 patients with SLE and 49 sex- and age-matched normal controls (NCs).Patients with SLE had higher mean salivary α-amylase levels (5.7 ± 4.6 U/mL vs 2.7 ± 2.5 U/mL, P < 0.001), anti-chromatin antibody levels (25.3 ± 22.9 U/mL vs 15.9 ± 10.9 U/mL, P < 0.001), and Beck Depression Index (BDI) scores (11.1 ± 9.2 vs 5.3 ± 5.1, P < 0.001) than NCs. However, salivary cortisol levels and Perceived Stress Scale (PSS) scores did not differ between the groups. The BDI scores correlated with the SLE disease activity index (SLEDAI) scores (r = 0.253, P = 0.011) and erythrocyte sedimentation rates (r = 0.234, P = 0.019). SLE patients with the highest-quartile PSS scores had significantly increased SLEDAI scores compared to those with the lowest-quartile PSS scores after 4 to 5 months' follow-up. Moreover, SLE patients with elevated SLEDAI scores had higher baseline PSS scores.Patients with SLE showed uncoupling of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis; higher salivary α-amylase and no different cortisol levels compared with NCs. Also, patients with SLE were more depressed, which correlated with disease activity. Furthermore, perceived stress was not correlated with disease activity; however, disease activity worsened several months later with elevated perceived stress levels.

Genetics of monoamine oxidase

Evidence for the genetic control of human MAO is now well established. The relationships of MAO activities to neuropsychiatric disorders or response to psychopharmacologic treatments are relatively unstudied. Preliminary findings from our own studies suggest that (1) blood MAO activity is a polygenically controlled trait; (2) there may be a subgroup of depressed patients with high MAO activity who are more severe symptomatically and more resistant to treatment, and (3) that men with atypical and mixed depressions respond more favorably than women to treatment with an MAO inhibitory drug.

[Advance in studies on natural antidepressant drugs and cytochrome P450]

In the fast pace of modern life and under the heavy work pressure, the prevalence of depression has increased year by year. Meanwhile, the demands for antidepressant drugs have also grown, especially the high-efficiency and low-toxicity natural antidepressant drugs, mainly including polyphenols, flavonoids, organic acids, alkaloids and terpenoids. Cytochrome P450 (CYP450) is a type of enzymes involving oxidative metabolism of drugs in vivo, and can change the pharmacokinetics and efficacy of drugs. Therefore, it is of important significant to define the effect of natural antidepressant drugs on CYP450 in human bodies, in order to improve the rational clinical medication, avoid drug interactions and reduce adverse reactions.

[The distribution of MAP kinase phosphatase-1 in the cerebrospinal fluid-contacting nucleus and its functional contribution to depressive behaviors]

The purpose of this research is to explore the distribution and expression of MAP kinase phosphatase-1 (MKP-1) in cerebrospinal fluid (CSF)-contacting nucleus in depression, and provide experimental evidence to reveal the biological function and regulatory mechanisms of CSF-contacting nucleus in depression. Depression model was produced by chronic forced swimming stress (CFSS) in Sprague-Dawley (SD) rats. Intracerebroventricular injection of cholera toxin subunit B (CTb) labeled with horseradish peroxidase (CB-HRP) was used to specifically mark distal CSF-contacting nucleus. The rate of animal growth and behavioral tests including sucrose preference test (SPT) and open field test (OFT) were used to validate the model of depression. The expressions of MKP-1 and fos proteins in CSF-contacting nucleus were detected by immunofluorescence. Software Image-Pro Plus version 6.0 was used to count the positive neurons. The results showed that, the distributions of MKP-1 were found in the CSF-contacting nucleus. After 28 days of swimming, the rats in stress group had a lower growth rate, a less consumption of sucrose and lower scores of OFT compared to control group. The number of neurons double labeled with CB-HRP/fos or CB-HRP/MKP-1 in stress group was significantly higher than that in control group (P < 0.01). These results suggest that the CSF-contacting nucleus may be involved in the process of depression via the MKP-1.

Essential elements in depression and anxiety. Part II

In this paper we continue to discuss the involvement of essential elements in depression and anxiety, and the possible mechanisms that link elements to the neurobiology underlying depression/anxiety. The present paper is focused on copper, selenium, manganese, iodine and vanadium. Different aspects of relationship between elements and depression or anxiety are reviewed, e.g. the association of the amount of an element in a diet or the serum level of an element and depressive or anxiety-like symptoms. Moreover, the relation of selected elements to the pathophysiology of depression or anxiety is discussed in the context of enzymes which require these elements as co-factors and are involved in the underlying pathophysiology of these disorders.

Proteasome modulator 9 gene SNPs, responsible for anti-depressant response, are in linkage with generalized anxiety disorder

Proteasome modulator 9 (PSMD9) gene single nucleotide polymorphism (SNP) rs1043307/rs2514259 (E197G) is associated with significant clinical response to the anti-depressant desipramine. PSMD9 SNP rs74421874 [intervening sequence (IVS) 3 + nt460 G>A], rs3825172 (IVS3 + nt437 C>T) and rs1043307/rs2514259 (E197G A>G) are all linked to type 2 diabetes (T2D), maturity-onset-diabetes-of the young 3 (MODY3), obesity and waist circumference, hypertension, hypercholesterolemia, T2D-macrovascular and T2D-microvascular disease, T2D-neuropathy, T2D-carpal tunnel syndrome, T2D-nephropathy, T2D-retinopathy, non-diabetic retinopathy and depression. PSMD9 rs149556654 rare SNP (N166S A>G) and the variant S143G A>G also contribute to T2D. PSMD9 is located in the chromosome 12q24 locus, which per se is in linkage with depression, bipolar disorder and anxiety. In the present study, we wanted to determine whether PSMD9 is linked to general anxiety disorder in Italian T2D families. Two-hundred Italian T2D families were phenotyped for generalized anxiety disorder, using the diagnostic criteria of DSM-IV. When the diagnosis was unavailable or unclear, the trait was reported as unknown. The 200 Italians families were tested for the PSMD9 T2D risk SNPs rs74421874 (IVS3 + nt460 G>A), rs3825172 (IVS3 +nt437 T>C) and for the T2D risk and anti-depressant response SNP rs1043307/rs2514259 (E197G A>G) for evidence of linkage with generalized anxiety disorder. Non-parametric linkage analysis was executed via Merlin software. One-thousand simulation tests were performed to exclude results due to random chance. In our study, the PSMD9 gene SNPs rs74421874, rs3825172, and rs1043307/rs2514259 result in linkage to generalized anxiety disorder. This is the first report describing PSMD9 gene SNPs in linkage to generalized anxiety disorder in T2D families.

Neurocognitive and neuropsychiatric phenotypes associated with the mutation L238Q of the α-L-iduronidase gene in Hurler-Scheie syndrome

The lysosomal enzyme α-L-iduronidase hydrolyzes terminal iduronic acid from heparan sulfate and dermatan sulfate, and is an essential step in GAG degradation. Mutations of its gene, IDUA, yield a spectrum of mucopolysaccharidosis (MPS) type I clinical disorders. The IDUA mutation, c.712T>A (p.L238Q) was previously noted as a mild mutation. In a longitudinal study of MPS brain structure and function (Lysosomal Disease Network), we found this mutation in 6 of 14 Hurler-Scheie syndrome patients in the age range of 15 to 25 years. We hypothesized that L238Q, when paired with a nonsense mutation, is significantly more severe than other missense-nonsense combinations.

METHODS

Of 6 patients with a L238Q mutation, the L238Q allele was paired with a nonsense mutation in 4 patients, paired with a deletion in 1, and with a splice site mutation in another. This group was compared to 6 Hurler-Scheie patients closely matched in age and mutation type. IQ and other neuropsychological tests were administered as part of the protocol. Medical history was compiled into a Physical Symptom Score (PSS). Assessment of IQ, attention, memory, spatial ability, adaptive function and psychological status were measured.

RESULTS

No group differences were found in mean age at evaluation (17.8 and 19.0 years), duration of ERT, or PSS. By history, all were reported to be average in IQ (4/6 with documentation) in early childhood. All (100%) of the L238Q group had a psychiatric history and sleep problems compared to none (0%) of the comparison group. Significant differences were found in depression and withdrawal on parent report measures. IQ was lower in the L238Q group (mean IQ 74) than the comparison group (mean IQ 95; p<0.016). Attention, memory, and visual-spatial ability scores were also significantly lower. Three occurrences of shunted hydrocephalus, and 4 of cervical cord compression were found in the L238Q group; the comparison group had one occurrence of unshunted hydrocephalus and two of cord compression.

DISCUSSION

The missense mutation L238Q, when paired with a nonsense mutation, is associated with significant, late-onset brain disease: psychiatric disorder, cognitive deficit, and general decline starting at a later age than in Hurler syndrome with a mutation-related rate of GAG accumulation and its pathologic sequelae. This particular genotype-phenotype may provide insight into the genesis of psychiatric illnesses more broadly. Consideration of methods for early, brain-targeted treatment in these patients might be considered.

Fluoxetine exposure during adolescence alters responses to aversive stimuli in adulthood

The mechanisms underlying the enduring neurobiological consequences of antidepressant exposure during adolescence are poorly understood. Here, we assessed the long-term effects of exposure to fluoxetine (FLX), a selective serotonin reuptake inhibitor, during adolescence on behavioral reactivity to emotion-eliciting stimuli. We administered FLX (10 mg/kg, bi-daily, for 15 d) to male adolescent [postnatal day 35 (P35) to P49] C57BL/6 mice. Three weeks after treatment (P70), reactivity to aversive stimuli (i.e., social defeat stress, forced swimming, and elevated plus maze) was assessed. We also examined the effects of FLX on the expression of extracellular signal-regulated kinase (ERK) 1/2-related signaling within the ventral tegmental area (VTA) of adolescent mice and Sprague Dawley rats. Adolescent FLX exposure suppressed depression-like behavior, as measured by the social interaction and forced swim tests, while enhancing anxiety-like responses in the elevated plus maze in adulthood. This complex behavioral profile was accompanied by decreases in ERK2 mRNA and protein phosphorylation within the VTA, while stress alone resulted in opposite neurobiological effects. Pharmacological (U0126) inhibition, as well as virus-mediated downregulation of ERK within the VTA mimicked the antidepressant-like profile observed after juvenile FLX treatment. Conversely, overexpression of ERK2 induced a depressive-like response, regardless of FLX pre-exposure. These findings demonstrate that exposure to FLX during adolescence modulates responsiveness to emotion-eliciting stimuli in adulthood, at least partially, via long-lasting adaptations in ERK-related signaling within the VTA. Our results further delineate the role ERK plays in regulating mood-related behaviors across the lifespan.

Experimental gastritis leads to anxiety- and depression-like behaviors in female but not male rats

Human and animals studies support the idea that there is a gender-related co-morbidity of pain-related and inflammatory gastrointestinal (GI) diseases with psychological disorders. This co-morbidity is the evidence for the existence of GI-brain axis which consists of immune (cytokines), neural (vagus nerve) and neuroendocrine (HPA axis) pathways. Psychological stress causes disturbances in GI physiology, such as altered GI barrier function, changes in motility and secretion, development of visceral hypersensitivity, and dysfunction of inflammatory responses. Whether GI inflammation would exert impact on psychological behavior is not well established. We examined the effect of experimental gastritis on anxiety- and depression-like behaviors in male and female Sprague-Dawley rats, and evaluated potential mechanisms of action. Gastritis was induced by adding 0.1% (w/v) iodoacetamide (IAA) to the sterile drinking water for 7 days. Sucrose preference test assessed the depression-like behavior, open field test and elevated plus maze evaluated the anxiety-like behavior. IAA treatment induced gastric inflammation in rats of either gender. No behavioral abnormality or dysfunction of GI-brain axis was observed in male rats with IAA-induced gastritis. Anxiety- and depression-like behaviors were apparent and the HPA axis was hyperactive in female rats with IAA-induced gastritis. Our results show that gastric inflammation leads to anxiety- and depression-like behaviors in female but not male rats via the neuroendocrine (HPA axis) pathway, suggesting that the GI inflammation can impair normal brain function and induce changes in psychological behavior in a gender-related manner through the GI-to-brain signaling.

Current place of monoamine oxidase inhibitors in the treatment of depression

This paper reviews the discovery and history of the use of irreversible monoamine oxidase (MAO) inhibitors (MAOIs) such as phenelzine, tranylcypromine and isocarboxazid, as well as the second generation selective and reversible MAOIs such as the MAO-A inhibitor, moclobemide and the MAO-B inhibitor, selegiline. Data for review were identified from a literature search of OvidSP Medline and PsycInfo performed in July 2012, using the subject terms and keywords of 'monoamine oxidase inhibitors', 'major depression', 'depressive disorder' and 'depression (emotion)'. The search was limited to papers published in the English language and from 2007 onward only. Irreversible MAOIs have the potential to treat the most challenging mood disorder patients including those with treatment-resistant depression, atypical depression and bipolar depression. Unfortunately, the use of irreversible MAOIs has been declining sharply due to lack of marketing and the excessive fears of clinicians. Moreover, few clinicians now have any experience, let alone comfort, in prescribing this class of antidepressants. The newer MAOIs are available as another option for the treatment of major depression but have not replaced the irreversible MAOIs for the specific sub-types of depression for which they are now recommended in most consensus guidelines and treatment algorithms. The pharmacology, drug interactions and dietary recommendations associated with the use of MAOIs are reviewed. With the appropriate dietary restrictions and attention to potential drug interactions with serotonin and noradrenaline agents this class of drugs can be used effectively and safely. The MAOIs still represent an important element in our therapeutic armamentarium. Despite recommendations by opinion leaders and consensus guidelines for the use of MAOIs in specific sub-types of depression, the prescription rate of MAOIs is far less than expected and is decreasing. The "bad reputation" and the lack of industry support for this class of agents (especially the irreversible MAOIs) must be overcome in order to continue to provide a potentially useful treatment for a very vulnerable yet substantial sub-population of mood disorder patients.

Maternal prenatal symptoms of depression and down regulation of placental monoamine oxidase A expression

OBJECTIVE

Maternal prenatal symptoms of depression and anxiety have been associated with altered neurodevelopmental outcomes in the child. These effects may be mediated in part by altered placental function, with increased fetal 5-hydroxytryptamine (5-HT) exposure being one possible mechanism. The current study aimed to determine whether maternal symptoms of depression or anxiety were associated with decreased placental expression of monoamine oxidase A (MAO A), the enzyme which metabolises 5-HT into 5-hydroxyindoleacetic acid. The localisation of MAO A in the placenta was also investigated.

METHODS

Pregnant women were recruited one day prior to elective caesarean and assessed using psychometric tests for symptoms of depression (Edinburgh Depression Scale) and anxiety (Spielberger State/Trait Index). Villous trophoblast tissue was extracted from each placenta and used for subsequent gene expression analysis (N=62). Localisation was studied using immunohistochemistry, with a specific polyclonal antibody.

RESULTS

Increasing symptoms of maternal depression were associated with a reduction in placental MAO A expression (r=-0.339, p=0.007, N=62). There was a trend for a similar correlation with symptoms of maternal trait anxiety, but not with state anxiety. MAO A was localised to the syncytiotrophoblast, the tissue between maternal and fetal blood.

CONCLUSIONS

These findings support the hypothesis that maternal mood is associated with altered placental function. A reduction in placental MAO A expression is consistent with a subsequent increase in fetal exposure to 5-HT.

Chronic fluoxetine treatment affects gene expression of catecholamine enzymes in the heart of depression model rats

Depression is associated with increased risk of coronary heart diseases. Selective serotonin reuptake inhibitors (SSRIs) have been proved to be very effective in normalizing symptoms of depression, but the data on possible influence of these drugs on cardiovascular function is controversial. Applying Taqman RT-PCR assay, the effect of chronic treatment with a SSRI antidepressant fluoxetine has been investigated on gene expression of catecholamine biosynthetic enzymes in all four heart chambers of rats with signs of depression. Depression was induced by exposing the animals to chronic unpredictable mild stress (CUMS). Tyrosine-hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) mRNA levels were decreased both in right and left atria, while phenylethanolamine N-methyltransferase (PNMT) mRNAs were increased in left atria and both ventricles of depression model rats. Fluoxetine elevated gene expression of TH and DBH in atria, but did not influence this process in the ventricles. Also, this antidepressant did not express a significant effect on the level of PNMT mRNA both in atria and ventricles. These results indicate that fluoxetine acted stimulating noradrenaline synthesis in the heart, which could lead to increased risk of heart disease.

Smoking related diseases: the central role of monoamine oxidase

Smoking is a major risk factor of morbidity and mortality. It is well established that monoamine oxidase (MAO) activity is decreased in smokers. Serotonin (5-HT), a major substrate for MAO that circulates as a reserve pool stored in platelets, is a marker of platelet activation. We recently reported that smoking durably modifies the platelet 5-HT/MAO system by inducing a demethylation of the MAO gene promoter resulting in high MAO protein concentration persisting more than ten years after quitting smoking. The present data enlarges the results to another MAO substrate, norepinephrine (NE), further confirming the central role of MAO in tobacco use-induced diseases. Thus, MAO could be a readily accessible and helpful marker in the risk evaluation of smoking-related diseases, from cardiovascular and pulmonary diseases to depression, anxiety and cancer. The present review implements the new finding of epigenetic regulation of MAO and suggests that smoking-induced MAO demethylation can be considered as a hallmark of smoking-related cancers similarly to other aberrant DNA methylations.

[Effect of electroacupuncture on hippocampal apoptosis and JNK signal pathway in chronic stress depression rats]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on hippocampal apoptosis and c-Jun N-terminal kinase (JNK) signal pathway in chronic stress depression rats so as to study its mechanism underlying acupuncture-induced improvement of depression.

METHODS

Sixty-five SD rats were randomly divided into control, control + EA, model, EA and Prozac groups, with 13 rats in each. Open-field test was used to detect the rats' behavior changes. The apoptotic rate of the hippocampal cells was detected by Annexin V fluorescein isothiocyanate (FITC)/ Propidium iodide (PI) (Annexin V-FITC/PI) double-staining, and the expression of hippocampal JNK protein detected by Western blot.

RESULTS

After repeated stress stimulation (21 days), the crossing numbers (1.8 +/- 0.2) and rearing times (0.5 +/- 0.01) in the model group were apparently lower than those (48.1 +/- 18.3, 14.2 +/- 2.4) in the control group and those (47.2 +/- 15.8, 13.5 +/- 2.6) in the control + EA group (P < 0.05). Compared with the model group, the crossing numbers and rearing times (40.2 +/- 10.1, 10.3 +/- 2.2) during 3 min in the EA group and those (39.8 +/- 12.4, 10.6 +/- 3.2) in the Prozac group were increased considerably (P < 0.05). The hippocampal apoptotic rate was significantly higher in the model group (67 +/- 10) than in the control (53 +/- 13) and control + EA groups (52 +/- 10, P < 0.05). In comparison with the model group, the apoptotic rate (29 +/- 9) of the EA group and that (51 +/- 13) of the Prozac group were significantly lower (P < 0.05). Compared with the control group, the phosphorylated JNK (p-JNK) level was considerably higher in the model group (P < 0.05); while compared with the model group, the p-JNK level was significantly lower in the EA and Pozac groups (P < 0.05). No apparent differences were found between the EA and and Prozac groups in the aforementioned indexes (P > 0.05).

CONCLUSION

EA can reduce hippocampal apoptotic rate and down-regulate hippocampal p-JNK level in depression rats, which is responsible for its effect in improving depression-induced decreased movement.

[Anxiety, depression and polymorphism of the gene encoding superoxide dismutase in patients with chronic obstructive pulmonary disease]

Chronic obstructive pulmonary disease (COPD) is a severe systemic disease leading to circulatory and respiratory failure. COPD is also a risk factor for the onset of anxiety and mood disturbances. Identification of the correlates of emotional disturbances in the course of COPD can make it possible, on the one hand, to prevent mental and behavioral disorders early in the course of this serious somatic disease, and on the other hand, to institute appropriate treatment. The aim of the study was to determine the correlation between the polymorphism of manganese superoxide dismutase signal peptide and the severity of anxiety and depression in COPD patients.

MATERIAL AND METHODS

The study group consisted of 57 patients with grade I, II and III COPD according to GOLD criteria. The control group consisted of 63 healthy nicotine addicts. In all the subjects, the genotype of position 9 of manganese superoxide dismutase signal peptide was determined, depression severity was measured with Beck Depression Scale, and anxiety as a trait and as a state was measured with Spielberg State/Trait Anxiety Inventory (STAI).

RESULTS

Among COPT patients, 16 subjects were found to have Ala/Ala genotype, 23 Val/Ala and 18 Val/Val. In the smokers' group Ala/Ala genotype was found in 29 cases, Val/Ala in 27 and Val/Val in 7. The distribution of genotype frequencies differed between the groups. In COPD patients, the mean depression severity assessed according to Beck Scale amounted to (16.52 +/- 5.63) and was higher than in smokers without COPD (13.85 +/- 4.24, p = 0.003828). The average severity of anxiety as a trait and as a state did not differ significantly in both groups. Among COPD patients, the mean severity of depressive disorders in subjects with Val/ Val genotype was 21.27 +/- 4.32 and was significantly higher than in those with Val/Ala (15.22 +/- 5.29) and Ala/Ala (12.87 +/- 3.72) genotypes. The severity of anxiety as a trait in COPD patients reached 7.72 +/- 1.21 in the subgroup with Val/Val genotype and was also higher than in those with Val/Ala genotype (6.69 +/- 1.48) and with Ala/Ala genotype (5.87 +/- 1.14). A similar correlation was observed for anxiety as a state (subjects with Val/Val genotype 6.78 +/- 1.06, with Val/Ala genotype 6.18 +/- 1.01 and with Ala/ Ala genotype 5.88 +/- 1.41). Among healthy smokers, the mean severities of depression, anxiety as a trait and anxiety as a state did not differ in subjects with different genotypes.

CONCLUSIONS

The study has demonstrated that the severity of depression is higher in COPD patients than in the group of healthy smokers. In the group of patients with COPD, Val/Val genotype at position 9 of MnSOD signal peptide is associated with more severe depression, anxiety as a trait and anxiety as a state in comparison with patients who have Val/Ala and Ala/Ala genotypes. No similar correlations were found in healthy smokers.

Indoleamine 2,3-dioxygenase activation and depressive symptoms in patients with coronary artery disease

An increase in immune-stimulated synthesis of kynurenine from tryptophan by indoleamine 2,3-dioxygenase (IDO) has been observed in patients with coronary artery disease (CAD). However, neuropsychiatric correlates of IDO activation remain unexplored. We hypothesize that IDO activation, as measured by the kynurenine to tryptophan (K/T) ratio, is associated with depressive symptoms in those with CAD. This cross-sectional study recruited subjects with CAD (n=95) from a cardiac rehabilitation facility. Demographic, anthropometric and cardiac data were obtained by chart review. Patients using an antidepressant were excluded. The presence of a major depressive episode or minor depression was assessed using a structured clinical interview for depression based on Diagnostic and Statistical Manual 4th edition criteria. The Center for Epidemiological Studies-Depression Scale (CES-D) was used to quantify depressive symptoms. A standardized exercise stress test was used to assess cardiopulmonary fitness as summarized using the peak volume of oxygen consumption (Peak VO(2)). Kynurenine and tryptophan were assayed from fasting plasma samples to obtain the K/T ratio. Higher K/T ratios were significantly associated with higher CES-D scores (beta=.322, p=.002) in a linear regression controlling for time since most recent acute coronary syndrome (tACS), age and sex. Twenty-four patients met criteria for depression (16 major depression; 8 minor depression). There was a trend towards higher K/T ratios in depressed vs. non-depressed patients (45.6+/-20.0 micromol/mmol vs. 38.5+/-15.7 micromol/mmol, F=3.778, p=.055) when controlling for age, sex and tACS. Activation of IDO is associated with the severity of depressive symptoms among patients with CAD.

Resolving the relationship between ApolipoproteinE and depression

Several studies have reported an association between the ApolipoproteinE-epsilon4 (APOE4) allele and depression among elders. However others have failed to find an association. Since APOE4 is a well recognized risk factor for Alzheimer dementia, cognitive status may represent an important confounder between APOE4 and depression. In this investigation, we examined the relationship between the ApolipoproteinE-epsilon4 allele and depression among elders accounting for cognitive status. Using a case-control design (n=1052), we investigated the association between ApolipoproteinE-epsilon4 and depression in Alzheimer disease patients (n=528) and in cognitively intact controls (n=524). We demonstrated an apparent association between the APOE4 allele and depression in the combined dataset (p=0.001) when not controlling for cognitive status. However, once stratified by the presence of Alzheimer disease, there was no association in either the Alzheimer group (p=0.290) or the cognitively intact controls (p=0.494). In this dataset there is no association between the ApolipoproteinE-epsilon4 allele and depression among those with Alzheimer disease or among cognitively intact elders. However there is a significant association between female gender and depression in the cognitively intact (p=0.003) but not among those with Alzheimer disease. Additionally, individuals with Alzheimer disease and depression had a significantly younger age of onset for their Alzheimer disease than those without depression (p=0.017).

[Influence of electroacupuncture of "Baihui" (GV 20) and "Sanyinjiao" (SP 6) on hippocampal 5-HT and AChE immuno-activity in chronic depression rats]

OBJECTIVE

To investigate the influence of electroacupuncture (EA) on 5-serotonin (5-HT) and acetyl cholinesterase (AChE) activities in hippocampus tissue in chronic stressed-induced depression rats.

METHODS

Thirty-two Wistar rats were randomized into normal control group (n=10), model group (n=11) and EA group (n=11). Chronic depression model was established by lonely raising, and chronic unpredictable mild stress for 21 days. EA (2 Hz, 1 mA) was applied to "Baihui" (GV 20) and "Sanyinjiao" (SP 6) for 20 minutes, once daily for 14 days. 5-HT and AChE expression of hippocampal CA 4 region was detected by using immunohistochemistry, and their integrated optical density (IOD) values were determined by using image analysis system.

RESULTS

Compared with normal control group, IOD values of 5-HT and AChE immuno-reaction (IR) positive neurons in hippocampal CA 4 region of model group decreased significantly (P<0.05). In comparison with model group, the IOD values of 5-HT and AChE IR positive neurons of CA 4 region in EA group increased significantly (P<0.05). No significant differences were found between EA and normal control groups in IOD values of both 5-HT and AChE IR positive neurons.

CONCLUSION

EA can upregulate 5-HT and AChE expression in hippocampal CA 4 region in depression rats, which may contribute to its effect in relieving depression.

Relationship of genetic variability and depressive symptoms to adverse events after coronary artery bypass graft surgery

OBJECTIVE

To assess genetic variability in two serotonin-related gene polymorphisms (MAOA-uVNTR and 5HTTLPR) and their relationships to depression and adverse cardiac events in a sample of patients undergoing coronary artery bypass surgery.

METHODS

A total of 427 coronary artery bypass graft (CABG) patients were genotyped for two polymorphisms and assessed for depressive symptoms at three time points, in accordance with the Center for Epidemiological Studies-Depression (CES-D): preoperative baseline; 6 months postoperative; and 1 year postoperative. Logistic regression was used to assess the association between depressive symptoms (CES-D = >16), genotype differences, and cardiac events. Because MAOA-uVNTR is sex-linked, males and females were analyzed separately for this polymorphism; sexes were combined for the 5HTTLPR analysis.

RESULTS

Depressed patients were more likely than nondepressed patients to have a new cardiac event within 2 years of surgery (p < .0001); depressed patients who carry the long (L) allele of the 5HTTLPR polymorphism were more likely than the short/short (S/S carriers to have an event (p = .0002). Genetic associations with 6-month and 1-year postoperative depressive symptoms do not survive adjustment for baseline depressive symptoms.

CONCLUSIONS

A serotonin-related gene polymorphism--5HTTLPR--was associated with adverse cardiac events post CABG, in combination with depressive symptoms. Because depressed patients with the L allele of the 5HTTLPR polymorphism were more likely to have an event compared with the S/S carriers, combining genetic and psychiatric profiling may prove useful in identifying patients at the highest risk for adverse outcomes post CABG.

[Effects of paroxetine on protein kinase PKA, PKC and CaMKII activity in different brain regions in a rat depression model]

OBJECTIVE

To evaluate the effects of paroxetine on protein kinase PKA, PKC and CaMKII activities in different brain regions in a rat model of depression.

METHODS

Thirty-six adult male SD rats were randomized into 6 groups, including one control group (I) and 5 groups of depression model established by forcing the rats to swim for 4 weeks. The 5 depression groups received no treatment (II) or were treated with paroxetine at a single dose (III), for a week (IV), 2 weeks (V) or 4 weeks (VI). The radioactivity of PKA, PKC and CaMKII in the hippocampus and prefrontal cortex was quantitatively measured using a liquid scintillation counter.

RESULTS

In the rat hippocampus, PKA and CaMKII activities were significantly lower in groups II, III, IV, and V than in groups I and VI (P<0.01 or P<0.05), but comparable between groups VI and I (P>0.05). PKC activity was significantly lower in group II than in group I (P<0.01), but showed no significant difference between the paroxetine-treated groups and group I (P>0.05). In the prefrontal cortex, the activity of PKA in groups I, II, III, and IV was similar (P>0.05), but all significantly lower than that in groups V and VI (P<0.01). PKC activity was significantly higher in groups II and III than that in group I and other paroxetine-treated groups (P<0.01), and similar between groups IV and I (P>0.05); groups V and VI had significantly lower PKC activity than group I (P<0.01). Group I had the highest CaMKII activity among the groups (P<0.01).

CONCLUSION

Chronic administration of paroxetine can reverse chronic stress-induced inhibition of PKA, PKC and CaMKII activity in rat hippocampus, while the effects of paroxetine on the protein kinases can be more complex in prefrontal cortex.

[Effects of electroacupuncture on behavior, plasma COR and expressions of PKA and PKC in hippocampus of the depression model rat]

OBJECTIVE

To probe into the mechanism of acupuncture for treatment of depression.

METHODS

Thirty-two healthy SD male rats were randomly divided into a normal group, a model group, an electroacupuncture (EA) group and a Maprotiline group. The depression rat model was made in the latter three groups, and from the second day of the experiment EA was given at Baihui (GV 20), "Yintang" (EX-HN 1), "Zusanli" (ST 36) and "Fenglong" (ST 40) in the EA group, once every other day; the rats in the Maprotiline group were treated with oral administration of Maprotiline hydrochroride, once each day. After treatment of 3 weeks, changes of behaviors, plasma cortisol (COR) level and expressions of protein kinase A (PKA) and protein kinase C (PKC) in hippocampus were observed in the rats.

RESULTS

In the depression model rats, the body weight increased slowly, and horizontal and vertical activities and consumption of sugar liquid significantly decreased; plasma cortisol content significantly increased; expressions of PKA and PKC in the hippocampus significantly reduced. In the rats of EA group, the score of behaviors, the consumption of sugar liquid and the increase of body weight were not significantly different to those in the model group, but the plasma cortisol level significantly decreased and closed to the normal level, and positive expressions of PKA and PKC in the hippocampus could be effectively reversed. In the Maprotiline group, the consumption of sugar liquid significantly increased and plasma cortisol level significantly decreased, and expressions of PKA and PKC in the hippocampus increased as compared with those in the model group.

CONCLUSION

The depression model rat has dysfunction of the hypothalamus-pituitary-adrenal axis (HPAA) and EA can regulate functions of HPAA. The mechanism is possibly carried out by regulating functions of relative enzymes in the signal transduction pathway in hippocampal cells.

Beta N-acetylglucosaminyltransferase V (Mgat5) deficiency reduces the depression-like phenotype in mice

The central nervous system (CNS) is rich in glycoconjugates, located on cell surface and in extracellular matrix. The products of Golgi UDP-GlcNAc:N-acetylglucosaminyltransferases (encoded by Mgat1, Mgat2, Mgat4 and Mgat5) act sequentially to generate the GlcNAc-branched complex-type N-glycans on glycoprotein receptors. While elimination of all the branched N-glycans in Mgat1(-/-) mouse embryos is lethal at neural tube fold stage, decreased branching is associated with late developmental defects similar to type 2 of congenital disorders of glycosylation, with developmental and psychomotor abnormalities. To study the role of complex-type N-glycans in brain function, we tested Mgat5(-/-) mice in a battery of neurological and behavioral tests. Despite the absence of tri- and tetra-antennary products, Mgat5(-/-) mice were not different from their wild-type littermates in physical and neurological assessments, anxiety level, startle reactivity and sensorimotor gating. However, they displayed a robust decrease in the immobility time in the forced swim test and the tail suspension test independent of locomotor activity, interpreted as a change in depression-like behavior. This effect was accentuated after chronic mild stress. Comparable increase in plasma corticosterone of Mgat5(+/+) and Mgat5(-/-) mice in response to acute stress shows an intact function of the hypothalamus-pituitary-adrenal axis. A change in social interactions was also observed. Our results indicate that Mgat5 modification of complex-type N-glycans on CNS glycoproteins is involved in the regulation of depression-like behavior.

[Lipid peroxidation and copper-zinc superoxide dismutase activity in patients treated with fluoxetine during the first episode of depression]

In recent years researchers have made a lot of studies to determine the molecular and neurochemical mechanisms which are the basis of depressive disorders. Apoptosis is a cause of the limbic system neuronal cells defect in patients suffering from depression. The antioxidant system is the best known molecular mechanism which protects the cells from apoptosis. This system exists inside and outside of the cells compartments. There is much evidence that antioxidant enzymes keep neuronal cells safe from apoptosis, which is a result of oxidative stress. It also limits the premature ageing of cells.

AIM

We tried to give an answer to three questions. 1. Is the activity of cooper-zinc superoxide dismutase (CuZnSOD) and lipid peroxydation level (TBARS) different in patients and the healthy control group? 2. Does the activity of CuZnSOD change due to fluoxetine treatment? 3. What is the difference of TBARS concentration in platelets isolated from patients before and after treatment?

METHOD

The study comprised of 32 patients diagnosed with depression. The activity of CuZnSOD in platelets was measured by Misra and Fridovich's method. The thrombocyte concentration of TBARS was measured by Placer and coop. method.

RESULTS AND CONCLUSIONS

1. The activity of CuZnSOD in platelets of depressive patients is lower than in the healthy control group, but the differences are not significant. 2. The activity of CuZnSOD rises after fluoxetine treatment. 3. The concentration of TBARS is higher in patients than in the healthy control group. 4. The intensity of lipid peroxydation is statistically lower after fluoxetine treatment.

[The influence of clomipramine on CYP2D6 activity]

AIM

Genetically determined activity ofCYP2D6 may be modified by some drugs through inhibition processes. Inhibition properties of TCA's were confirmed mainly in in vitro studies. The aim of the study was to assess the influence of clomipramine on CYP2D6 activity in vivo.

METHOD

11 patients diagnosed with depression according to ICD-10 and DSM-IV (major depression) criteria were included in the study. In all the cases clomipramine therapy was indicated. CYP2D6 activity was assessed by the phenotyping method. All patients were treated simultaneously. Each of the patients ingested one tablet containing 100 mg of sparteine sulfate. Urine excreted during the following 6 h was collected. Based on sparteine metabolic ratio (MR) the phenotype status was estimated twice: after the wash-out period, before clomipramine treatment, sparteine metabolic ratio (MRI), and after 2-weeks of clomipramine treatment (MR2).

RESULTS

During clomipramine treatment MR2 values were statistically significantly higher than MRI. In 3 patients (27.3%) treated with clomipramine the changes of phenotype status were observed.

CONCLUSIONS

Clomipramine is a CYP2D6 inhibitor and may change the CYP2D6 phenotype status (EM into PM).

Role of glycogen synthase kinase-3beta in early depressive behavior induced by mild traumatic brain injury

Traumatic brain injury (TBI) is a triggering event for a set of pathophysiological changes and concomitant depressive behavior. Glycogen synthase kinase-3 (GSK-3) is a potent in vivo regulator of cell apoptosis and, in addition, is implicated in depressive behavior. In this study, we investigated the role of GSK-3 in the physiological model of mild TBI (mTBI) at both the cellular and behavior levels. mTBI resulted in increased phosphorylation of inhibitory site serine(9) of GSK-3beta, which coincided with increased serine(473) phosphorylation of its upstream kinase PKB and accumulation of its downstream target beta-catenin in the hippocampus. mTBI induced a depressive behavior which was evident as early as 24 h post-injury. Pretreatment with GSK-3 inhibitors, lithium, or L803-mts prevented mTBI-induced depression. We suggest that mTBI elicits a pro-survival cascade of PKB/GSK-3beta/beta-catenin as part of a rehabilitation program. Furthermore, the use of selective GSK-3 inhibitors may have therapeutic benefits in treatment conditions associated with brain injury.

The depressive-like behaviors are correlated with decreased phosphorylation of mitogen-activated protein kinases in rat brain following chronic forced swim stress

In the present study, 40 Sprague-Dawley rats were divided into forced swim stress group and controls, with 20 rats in each group (10 for behavioral tests, 10 for protein detection). The forced swim stress group received swim stress for 14 consecutive days, and the controls were stress-free. After stress, 20 rats were tested for behavioral observation using body weight gain, open field, elevated plus-maze and saccharin preference test, and 20 rats were decapitated for protein detection. The extracellular signal-regulated kinase (Erk) and phospho-Erk (P-Erk) in the hippocampus and prefrontal cortex were determined using western blot. It was found that the body weight gain of stressed animals during the 7 stressed days and the 14 stressed days was significantly decreased compared to that of controls. Stressed animals spent less time in open arms and longer time in closed arms. The stressed animals demonstrated decreased locomotor activity and increased grooming in open field. The saccharin solution intake and the ratio of saccharin solution intake to total liquid intake were both decreased in the stressed group. Stressed animals showed decreased P-Erk2 and decreased ratio of P-Erk2 to total Erk2 in the hippocampus and prefrontal cortex, but their Erk1/2 was increased in the prefrontal cortex with no change in hippocampus. The saccharin solution intake positively correlated with the P-Erk2 in the hippocampus and negatively correlated with the Erk2 in the prefrontal cortex. In conclusion, chronic forced swim stress was a good animal model of depression, and it induced depressive-like behavior and decreased P-Erk2 in the hippocampus and prefrontal cortex in rats. The depressive-like behaviors were correlated with decreased phosphorylation of Erk, which suggested that the dysfunction of Erk activity might be one of biological mechanisms underlying depression induced by stress.

Behavioral characterization of CD26 deficient mice in animal tests of anxiety and antidepressant-like activity

CD26 exhibits a dipeptidylpeptidase-IV function (DPPIV) which regulates neuropeptide activity by N-terminal processing. Because abnormal plasma DPPIV was associated in mammals with behavioral changes, we examined the behavior of CD26-/- mice resulting from targeted inactivation of the gene. These animals had a decreased immobility in the forced swim and tail suspension tests, indicating a reduced depression-like behavior. We addressed some factors that could affect these results. No major differences between mutants and controls were observed in the black/white box test that investigates anxiety. In the hole-board apparatus that explores both curiosity and anxiety, CD26-/- mice of both genders made significantly more head dips than controls. In a motor activity test, mutants displayed higher horizontal and vertical activities i.e. increased novelty-induced behavioral activation. We conclude that DPPIV inactivation in mice broadly leads to an antidepressant-like and hyperactive phenotype.

[The relationship between the Wnt signaling and the psychiatric diseases]

It has been demonstrated that the neuronal plasticity and resilience could participate in the pathophysiology of neurodegenerative diseases such as Alzheimer and others like depression and schizophrenia. Recently, it has been proposed a new intracellular pathway, known as Wnt pathway, which could be related to the induction of the plastic changes mentioned above. The glycogen synthase kinase-3beta (GSK-3beta), one of the main enzymes of the Wnt signaling, has been associated to Alzheimer;s and schizophrenia diseases etiology. Furthermore, the mood stabilizing agents;s action mechanism, like lithium and valproic acid, implies the inhibition of this protein. The issue of this work is to describe the proteins that are recruited when this pathway is activated and the GSK-3beta role in the pathologies mentioned.

Keynote review: phosphodiesterase-4 as a therapeutic target

Cyclic AMP (cAMP) is a key second messenger in all cells. It is compartmentalized within cells and its levels are controlled, as a result of spatially discrete signaling cassettes controlling its generation, detection and degradation. Underpinning compartmentalized cAMP signaling are approximately 20 members of the phosphodiesterase-4 (PDE4) family. The selective inhibition of this family generates profound, functional effects and PDE4 inhibitors are currently under development to provide potential, novel therapeutics for the treatment of inflammatory diseases, such as asthma, chronic obstructive pulmonary disease and psoriasis, as well as treating depression and serving as cognitive enhancers. Here, we delineate the range of PDE4 isoforms, their role in signaling, their structural biology and related preclinical and clinical pharmacology.

Genotype-dependent activity of tryptophan hydroxylase-2 determines the response to citalopram in a mouse model of depression

Polymorphism of tryptophan hydroxylase, the rate-limiting enzyme in the synthesis of brain serotonin (5-HT), is associated with less synthesis of brain 5-HT in DBA/2J and BALB/c than in C57BL/6J and 129/Sv mice. We selected the forced swimming test, a mouse model used to assess the antidepressant potential of drugs, and neurochemical techniques to study strain differences in the response to citalopram, a selective 5-HT reuptake inhibitor. Citalopram reduced immobility time in C57BL/6J and 129/Sv mice but had no such effect in DBA/2J and BALB/c mice. The drug reduced accumulation of 5-hydroxytryptophan (5-HTP), an indicator of 5-HT synthesis, in C57BL/6J and 129/Sv mice but much less in DBA/2J and BALB/c mice. Pretreatment with tryptophan raised 5-HTP accumulation and reinstated the antidepressant-like effect of citalopram in DBA/2J and BALB/c mice, whereas pharmacological inhibition of 5-HT synthesis prevented the effect of citalopram in C57BL/6J and 129/Sv mice. Because there were no strain differences in catecholamine synthesis, locomotor activity, and brain levels of citalopram at the end of the behavioral test, the results suggest that the failure of citalopram to reduce immobility time in DBA/2J and BALB/c mice is attributable to genotype-dependent impairment of 5-HT synthesis. Interstrain comparisons could probably be a useful strategy for understanding the mechanisms underlying the response to selective serotonin reuptake inhibitors.

Na+,K(+)-ATPase activity is reduced in hippocampus of rats submitted to an experimental model of depression: effect of chronic lithium treatment and possible involvement in learning deficits

This study was undertaken to verify the effects of chronic stress and lithium treatments on the hippocampal Na+,K(+)-ATPase activity of rats, as well as to investigate the effects of stress interruption and post-stress lithium treatment on this enzyme activity and on spatial memory. Two experiments were carried out; in the first experiment, adult male Wistar rats were divided into two groups: control and submitted to a chronic variate stress paradigm, and subdivided into treated or not with LiCl. After 40 days of treatment, rats were killed, and Na+,K(+)-ATPase activity was determined. In the second experiment, rats were stressed during 40 days, and their performance was evaluated in the Water Maze task. The stressed group was then subdivided into four groups, with continued or interrupted stress treatment and treated or not with lithium for 30 additional days. After a second evaluation of performance in the Water Maze, rats were killed and Na+,K(+)-ATPase activity was also measured. Results showed an impairment in Na+,K(+)-ATPase activity and in Water Maze performance of chronically stressed rats, which were prevented by lithium treatment and reversed by lithium treatment and by stress interruption. These results suggest that the modulation of Na+,K(+)-ATPase activity may be one of the mechanisms of action of lithium in the treatment of mood disorders.

Effects of potassium channel inhibitors in the forced swimming test: Possible involvement of l-arginine-nitric oxide-soluble guanylate cyclase pathway

The effects of inhibitors of different subtypes of potassium (K+) channels were investigated in the mouse forced swimming test (FST). The treatment of animals with tetraethylammonium (TEA, a non-specific inhibitor of potassium channels, 0.25-2.5 ng/site, intracerebroventricular, i.c.v.), glibenclamide (an ATP-sensitive potassium channels (K(ATP) inhibitor, 0.05-5 ng/site, i.c.v.), apamine (a small conductance calcium-activated potassium channels inhibitor (SKCa), 0.1-1 ng/site, i.c.v.), charybdotoxin (a large- (big, BK) and intermediate- (IK) conductance calcium-activated potassium channels inhibitor, 2.5-25 ng/site, i.c.v.) produced an anti-depressant-like effect in the FST. At the highest effective doses, none of the drugs affected the locomotor activity in an open-field. Besides that, the pre-treatment of animals with l-arginine (a nitric oxide (NO) precursor, 750 mg/kg, intraperitoneal, i.p.) or sildenafil (a specific phosphodiesterase type 5 (PDE5) inhibitor, 5 mg/kg, i.p.) prevented the anti-depressant-like effect of all K+ channel inhibitors. The present results demonstrate that the decrease in the immobility time in the FST elicited by the inhibition of several subtypes of K+ channels is also dependent on the inhibition of NO-cGMP synthesis.

Hypothalamic nitric oxide synthase in affective disorder: focus on the suprachiasmatic nucleus

Depression is frequently associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which leads to repeated episodes of hypercortisolemia. Hypothalamic paraventricular neurons are believed to trigger these processes by aberrant generation and/or release of corticotropin releasing hormone, oxytocin, vasopressin, and nitric oxide (NO). Recent findings from two independent laboratories have demonstrated that the suprachiasmatic nucleus, which in part controls the cellular activity of paraventricular neurons (PVN), is also involved in affective disorder. The aim of the present study was to elucidate by stereological analysis, whether suprachiasmatic nucleus (SCN) nitric oxide synthase and neurophysin generating neurons are affected in neuropsychiatric disorders. We show that compared to controls the number of nitric oxide synthase immunoreactive neurons is greatly reduced both in depression and in schizophrenia. In subjects with affective disorder there was a correlation between the number of NOS-expressing cells and duration of treatment with antidepressants. The number of neurophysin-expressing SCN neurons was also fewer in cases with mood disorder. It is concluded that SCN-derived NO may be a relevant pathophysiological factor in neuropsychiatric disorders.