Evidence for an inhibitory immunomodulatory effect of selected antidepressants on rat splenocytes: possible relevance to depression and hyperactive-immune disorders

Complex Effects of Sertraline and Citalopram on In Vitro Murine Breast Cancer Proliferation and on In Vivo Progression and Anxiety Level

Some selective serotonin reuptake inhibitors (SSRIs), primarily sertraline, demonstrate anti-proliferative activity in malignant cell-lines and in xenografted mouse models of colorectal tumor. There is, however, a paucity of comparative studies on the anti-tumor effects of SSRIs. We compared the in vitro and in vivo effects of sertraline and citalopram on murine 4T1 breast cancer. Grafted mice were used to determine the rate of tumor growth and survival as well as the impact of stress and antidepressant treatment on tumor progression and mortality and on pro-inflammatory cytokines. Sertraline, in the micromolar range, but not citalopram, induced a significant in vitro concentration-dependent inhibition of murine 4T1 cell proliferation and splenocyte viability. In contrast, sertraline (10 mg/kg/d), enhanced in vivo tumor growth. Contrary to the study's hypothesis, chronic mild stress did not modify tumor growth in grafted mice. The in vitro effects of sertraline on tumor growth seem to be the opposite of its in vivo effects. The impact of sertraline treatment on humans with breast cancer should be further investigated.

Identification of Gene Co-Expression Modules and Core Genes Related to Immune Disorders in Major Depression Disorder

Introduction

Various studies have confirmed the connection between the mental state and the immune system, that is, mental activities can regulate immune function, and immune system disorders can not only lead to bodily diseases but also changes related to mentality, behavior, personality, and aging. However, the specific regulatory mechanism and key genes are still unclear.

Methods

We obtained the peripheral blood gene sequencing data from patients with major depression and normal volunteers from the GEO database and evaluated the scores of different immune cells by immune scoring algorithm. Using the immune scores as clinical data, a weighted gene co-expression network analysis (WGCNA) was carried out to study the association between the clinical characteristics and modules. Therefore, providing an opportunity to lock modules and core genes which are highly related to the immune regulation of major depression.

Results

Thirteen co-expression modules were clustered from 20,011 genes, the yellow module had a positive correlation with CD4⁺ T cell, CD8⁺ T cell, B cell, and NK cell immune scores, and a negative correlation with purple module. Functional annotation and signaling pathway analysis illustrated that the yellow module is mostly enriched in thymus development, T cell co-stimulation and differentiation, and B cell activation. Genes in the purple module were primarily related to inhibition of protein phosphorylation, leukocyte migration, promotion of apoptosis and hypoxia and other signaling pathways. Additionally, hub genes in the yellow and purple modules were detected, in which SKAP1 and RALB may be important regulatory genes affecting the immune status of patients with depression.

Discussion

In general, our study reveals the key genes related to the decrease in CD4⁺ T cells, CD8⁺ T cells, and B cells, in the peripheral blood of patients with depression, which provides some new insights and understandings for the clinical treatment and diagnosis of major depression. Drug design targeting these targets may provide the possibility for the treatment of major depression.

Analgesic effect of quetiapine in a mouse model of cancer-induced bone pain

BACKGROUND/AIMS

Cancer-induced bone pain (CIBP) is one of the most common pains in patients with advanced neoplasms. Because of treatment-associated side effects, more than half of cancer patients are reported to have inadequate and undermanaged pain control. New mechanism-based therapies must be developed to reduce cancer pain. Quetiapine is a commonly used atypical antipsychotic drug. We report a study of the potential analgesic effects of quetiapine in a mouse model of CIBP and examine the mechanism of bone pain by analyzing the expression of various nociceptors.

METHODS

Fifteen male C3H/HeN mice were arbitrarily divided into five groups: control and, CIBP with no treatment, quetiapine treatment, opioid treatment, and melatonin treatment. The mice were tested for mechanical hyperalgesia by determining the nociceptive hind paw withdrawal pressure threshold. Tissues from tibia were removed and subjected to quantitative and qualitative evaluations of transient receptor potential vanilloid 1 (TRPV1), TRPV4, acid-sensing ion channel 1 (ASIC1), ASIC2, and ASIC3 expression.

RESULTS

Paw withdrawal pressure threshold was improved in the quetiapine treatment group compared with the CIBP group. Expression of TRPV1, TRPV4, ASIC1, ASIC2, and ASIC3 in the CIBP with quetiapine treatment group was significantly lower than that in the CIBP group.

CONCLUSIONS

Our results suggest an analgesic effect of quetiapine in the CIBP animal model and implicate TRPV and ASICs as potential targets for cancer pain management.

Potential antiinflammatory effects of acupuncture in a chronic stress model of depression in rats

Accumulating evidence indicates that inflammation may contribute to the pathophysiology of depression. Acupuncture in traditional Chinese medicine has been considered an effective treatment for depression. However, whether the mechanisms that underlie the antidepressant effect of acupuncture are related to its antiinflammatory properties remains unclear. In the present study, rats were exposed to chronic unpredictable mild stress (CUMS) for 28 days to induce depressive-like behavior. Body weight, sucrose preference, and locomotor activity in the open field were measured. After the behavioral tests, reverse transcription polymerase chain reaction was used to determine the mRNA expression of proinflammatory cytokines (interleukin-1β [IL-1β], interleukin-6 [IL-6], and tumor necrosis factor-α [TNF-α]), and enzyme-linked immunosorbent assay was used to detect cytokine concentrations. CUMS rats exhibited decrease in body weight, sucrose preference, and locomotor activity in the open field test. Chronic acupuncture and fluoxetine treatment reversed CUMS-induced depressive-like behavior. Compared with control rats, the mRNA and protein expression of IL-1β, IL-6, and TNF-α in the hippocampus and prefrontal cortex and cytokine concentrations in serum significantly increased in CUMS rats. Acupuncture and fluoxetine treatment significantly decreased the levels of proinflammatory cytokines in the hippocampus, prefrontal cortex, and serum. These results suggest that acupuncture has antidepressant-like effects, and its mechanism of action appears to involve the inhibition of proinflammatory cytokines.

The impact of mitochondrial aldehyde dehydrogenase (ALDH2) activation by Alda-1 on the behavioral and biochemical disturbances in animal model of depression

The etiology of depression remains still unclear. Recently, it has been proposed, that mitochondrial dysfunction may be associated with development of mood disorders, such as depression, bipolar disorder and anxiety disorders. Mitochondrial aldehyde dehydrogenase (ALDH2), an enzyme responsible for the detoxification of reactive aldehydes, is considered to exert protective function in mitochondria. We investigated the influence of Alda-1, a small-molecule activator of ALDH2, on depressive- and anxiety-like behaviors in an animal model of depression - the prenatally stressed rats - using behavioral, molecular and proteomic methods. Prolonged Alda-1 administration significantly increased the climbing time, tended to reduce the immobility time and increased the swimming time of the prenatally stressed rats in the forced swim test. Moreover, treatment of prenatally stressed rats with Alda-1 significantly increased number of entries into the open arms of the maze and the time spent therein, as assessed by elevated plus-maze test. Such actions were associated with reduction of plasma 4-HNE-protein content, decrease of TNF-α mRNA and increase of PGC-1α (regulator of mitochondrial biogenesis) mRNA level in the frontal cortex and hippocampus of the prenatally stressed rats as well as with normalization of peripheral immune parameters and significant changes in expression of 6 and 4 proteins related to mitochondrial functions in the frontal cortex and hippocampus, respectively. Collectively, ALDH2 activation by Alda-1 led to a significant attenuation of depressive- and anxiety-like behaviors in the prenatally stressed rats. The pattern of changes suggested mitoprotective effect of Alda-1, however the exact functional consequences of the revealed alterations require further investigation.

The effects of sertraline administration from adolescence to adulthood on physiological and emotional development in prenatally stressed rats of both sexes

Sertraline (SERT) is a clinically effective Selective Serotonin Reuptake Inhibitor (SSRI) known to increase and stabilize serotonin levels. This neurotransmitter plays an important role in adolescent brain development in both rodents and humans, and its dysregulation has been correlated with deficits in behavior and emotional regulation. Since prenatal stress may disturb serotoninergic homeostasis, the aim of this study was to examine the long-lasting effects of exposure to SERT throughout adolescence on behavioral and physiological developmental parameters in prenatally stressed Wistar rats. SERT was administered (5 mg/kg/day p.o.) from the age of 1-3 months to half of the progeny, of both sexes, of gestating dams stressed by use of a restraint (PS) or not stressed. Our data reveal that long-term SERT treatment slightly reduced weight gain in both sexes, but reversed the developmental disturbed "catch-up" growth found in PS females. Neither prenatal stress nor SERT treatment induced remarkable alterations in behavior and had no effects on mean startle reflex values. However, a sex-dependent effects of PS was found: in males the PS paradigm slightly increased anxiety-like behavior in the open field, while in females, it impaired startle habituation. In both cases, SERT treatment reversed the phenomena. Additionally, the PS animals exhibited a disturbed leukocyte profile in both sexes, which was reversed by SERT. The present findings are evidence that continuous SERT administration from adolescence through adulthood is safe in rodents and lessens the impact of prenatal stress in rats.

Fluoxetine signature on hippocampal MAPK signalling in sex-dependent manner

A growing body of evidence indicates that mitogen-activated protein kinase (MAPK) participates in various stress-induced responses and is considered to be one of the pathophysiological mechanisms in depression. Surprisingly, the effect of antidepressants on MAPKs is almost unexplored, particularly from the perspective of sexes. The present study investigates the cytoplasm-nuclear distribution of MAPK family, c-Jun N-terminal kinases (JNKs) 1, 2 and 3; extracellular signal-regulated kinases (ERKs) 1 and 2; and p38 kinases, as well as their phosphoisoforms in the hippocampus of chronically stressed female and male rats and upon chronic fluoxetine treatment. Additionally, we analysed crosstalk between MAPK signalling and depressive-like behaviour which correlated with brain-derived neurotrophic factor (BDNF) expression. Our results emphasize a gender-specific and compartment-dependent response of MAPKs to stress and fluoxetine. In females, stress decreased pp38 and pJNK and induced cytosolic retention of pERKs which reduced all nuclear pMAPKs. These changes correlated with altered BDNF expression and behaviour. Similarly, in males, stress decreased pp38 but promoted nuclear translocation of pJNKs and pERKs. These stress alterations of pMAPKs in males were not associated with BDNF expression and depressive-like behaviour. Fluoxetine treatment in stressed females upregulated whole pMAPK signalling particularly those in nucleus which was followed with BDNF expression and normalization of behaviour. In stressed males, fluoxetine affected only cytosolic pJNKs, while nuclear pMAPK signalling and BDNF expression were unaffected even though fluoxetine normalized behaviour. Overall, our results suggest existence of gender-specific mechanism of fluoxetine on nuclear pMAPK/BDNF signalling and depressive-like behaviour and reinforce the antidepressant dogma that females and males respond differently to certain antidepressants.

The use of a selective serotonin reuptake inhibitor decreases heavy alcohol exposure-induced inflammatory response and tissue damage in rats

Alcohol intoxication and psychiatric medication overdoses, including antidepressants, are common emergency room events. Heavy alcohol and antidepressant exposure are able to induce changes in cytokines disturbing normal physiology. We examined the inflammatory and physiological effects of selective serotonin reuptake inhibitor (SSRI) medication after heavy alcohol exposure. Rats were randomly divided into Alc (EtOH 5g/kg, intravenous infusion for 3 h), SSRI (paroxetine oral intake) and Alc+SSRI groups. Serum samples were collected to measure blood ethanol, aspartate transferase, alanine transferase, creatine phosphokinase, lactate dehydrogenase, amylase, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels. Lactate dehydrogenase levels in bronchoalveolar lavage fluid were also examined. Liver, pancreas and lungs were removed after sacrifice and any pathological changes were catalogued. Ethanol infusion resulted in blood levels of ethanol of >100 mg/dL after ethanol infusion. Serum levels of aspartate transferase, alanine transferase, creatine phosphokinase, lactate dehydrogenase, amylase, TNF-α and IL-6 in the Alc+SSRI group were lower than in the Alc group. Moreover, pathological damages to the liver, pancreas and lungs were slightly lower in the Alc+SSRI group than in the Alc group. These findings suggested that SSRI is able to decrease the release of pro-inflammatory cytokines and thereby reduce liver and pancreas damage after heavy alcohol exposure.

Mesenchymal stem cells protect from sub-chronic phencyclidine insult in vivo and counteract changes in astrocyte gene expression in vitro

Mesenchymal stem cells (MSCs) are an attractive cell source for regenerative medicine strategies in brain diseases. Experimental studies have shown that repeated administration of phencyclidine (PCP) leads to schizophrenia-like behavioral changes in mice. The aim of the present study was to explore the effectiveness of MSC transplantation into the hippocampus in attenuating PCP-induced social behavior deficits. PCP was administered subcutaneously to C57bl mice (10mg/kg daily) for 2 weeks. On the first day of PCP administration, adult human MSCs were transplanted into the hippocampus. A week after the last PCP dose, the mice underwent social preference testing. MSC transplantation was associated with a significant reduction in the adverse social behavior induced by PCP. Immunohistochemical analysis revealed that the stem cells survived in the mouse brain, and hippocampal Western blot analysis revealed a statistical trend towards a decrease in cleaved caspase 3 protein levels in the stem cell treated group. Upon in vitro co-culture of astrocytes and MSCs, the MSCs, in the presence of PCP, positively regulated astrocyte expression of genes involved in glutamate metabolism and antioxidant defenses. These findings suggest that MSC transplantation into the hippocampus may serve as a novel neuroprotective tool for the treatment of the PCP-induced schizophrenia-like social endophenotype. The mechanism underlying the beneficial behavioral effect may involve modulation of host astrocyte functioning, including glutamate processing and antioxidant capacity.

Fluoxetine reduces murine graft-versus-host disease by induction of T cell immunosuppression

Serotonin reuptake inhibitors (SRIs) are widely used drugs in the treatment of depression and anxiety disorders. Although SRIs are generally regarded as safe drugs with relatively few side effects, literature suggests that high concentrations of SRIs may alter immune function. We investigated whether high-dose treatment with fluoxetine was able to suppress acute graft-versus-host disease (GvHD) in a MHC-matched, minor histocompatibility antigen mismatched murine bone marrow transplantation model. We found that high doses fluoxetine induce a significant reduction of clinical symptoms and increase survival of these animals. The amelioration of clinical GvHD was accompanied by a reduced expansion of alloreactive T cells. We further analyzed the direct in vitro effect of six SRIs on the viability and proliferation of human T cells and found an anti-proliferative and pro-apoptotic effect that was significantly larger in activated than in resting T cells. We discuss these results in the light of potential future exploration of SRIs as a novel class of T cell immunosuppressive drugs.

Putative neuroprotective agents in neuropsychiatric disorders

In many individuals with major neuropsychiatric disorders including depression, bipolar disorder and schizophrenia, their disease characteristics are consistent with a neuroprogressive illness. This includes progressive structural brain changes, cognitive and functional decline, poorer treatment response and an increasing vulnerability to relapse with chronicity. The underlying molecular mechanisms of neuroprogression are thought to include neurotrophins and regulation of neurogenesis and apoptosis, neurotransmitters, inflammatory, oxidative and nitrosative stress, mitochondrial dysfunction, cortisol and the hypothalamic-pituitary-adrenal axis, and epigenetic influences. Knowledge of the involvement of each of these pathways implies that specific agents that act on some or multiple of these pathways may thus block this cascade and have neuroprotective properties. This paper reviews the potential of the most promising of these agents, including lithium and other known psychotropics, aspirin, minocycline, statins, N-acetylcysteine, leptin and melatonin. These agents are putative neuroprotective agents for schizophrenia and mood disorders.

Antidepressants: influence on cancer and immunity?

Two decades ago, it was hypothesized that antidepressants could alter the course of neoplastic diseases. However, contradictory findings indicated that antidepressants could either have carcinogenic properties or improve the disease outcome. Intriguingly, controversial results were reported on the action of antidepressant drugs on immune function. Further hypotheses proposed that antidepressants could indirectly affect the cancer prognosis through the modulation of antitumor activity. Here we review the literature in order to elucidate the influence of antidepressants on cancer and immunity.

Interplaying factors that effect multiple sclerosis causation and sustenance

The author hypothesized that multiple sclerosis (MS) is a humoral autoimmune disease, caused by faulty interplay between myelin-specific, dimeric IgE, specifically competing non-IgE antibodies and IgE-triggered degranulating mast cells. The principal fault was believed to be insufficient quantity of protective, specific non-IgE antibodies. Also conjectured was the possibility of an unexpected and adverse immune suppression caused by none-MS pharmaceuticals being consumed by patients for their MS or for other conditions. To test both hypotheses, a mimotopic, peptide antigen-based, serum immunoassay was developed to measure dimer-bound IgE excess among MS patients, wherein the IgE specifically complexes with two or more myelin surface epitopes at an interval of 40–100 Angstroms, a separation critical for mast cell degranulation and cell damaging effect. MS test sensitivity and specificity, when analyzing five previously untreated patients for dimeric IgE presence, was 100%. In direct comparison, twenty age- and gender-matched female and male control subjects were test negative. Analysis of 35 multiple sclerosis patients, who were concomitantly being treated with potentially immunosuppressive pharmaceuticals, appeared to show the substances' negative effect upon MS causation, progression, or specific immunoassay performance. Therefore, MS is likely an autoimmune disease caused by IgE-mediated mast cell degranulation possibly in conjunction with immunosuppressive agents.

Immunomodulatory effect of sertraline in a rat model of rheumatoid arthritis

OBJECTIVE

Previous studies suggest that selective serotonin reuptake inhibitors (SSRIs) modulate immune system functionality. SSRIs are the preferred treatment for major depressive disorder (MDD). A high rate of MDD is observed in rheumatoid arthritis (RA) patients. The aim of this study was to evaluate immunological effects of SSRIs in a rat model of RA.

METHODS

Adjuvant arthritis was induced in 8-week-old Lewis rats; in the first set of experiments following the induction, 15.3 or 30.6 mg/kg of sertraline was daily injected into the ankle joint of the left rear leg. Clinical disease activity was evaluated and the findings compared with the 3 untreated legs and with control groups given methotrexate (MTX) or vehicle only at the same site. In a second set of experiments, the effect of 5, 25 and 50 mg/kg daily oral sertraline was evaluated in the same rat model. Splenocyte viability and inflammatory mediators were evaluated.

RESULTS

The sertraline-treated rats showed a significant reduction in clinical arthritis compared to controls, at all doses given, accompanied by a significant increase in interleukin 10 and a decrease in tumor necrosis factor-α levels and cycloxygenase-2 production, without lymphotoxicity. There was no significant difference from MTX, the first-line treatment for RA patients. Oral sertraline had a significant anti-inflammatory effect at all doses. There was no treatment × time effect.

CONCLUSION

The beneficial effects of sertraline in this rat model of arthritis have clinical implications for its use in humans. Large-scale clinical efficacy trials are needed.

Intracerebral adult stem cells transplantation increases brain-derived neurotrophic factor levels and protects against phencyclidine-induced social deficit in mice

Stem cell-based regenerative therapy is considered a promising cellular therapeutic approach for the patients with incurable brain diseases. Mesenchymal stem cells (MSCs) represent an attractive cell source for regenerative medicine strategies for the treatment of the diseased brain. Previous studies have shown that these cells improve behavioral deficits in animal models of neurological disorders such as Parkinson's and Huntington's diseases. In the current study, we examined the capability of intracerebral human MSCs transplantation (medial pre-frontal cortex) to prevent the social impairment displayed by mice after withdrawal from daily phencyclidine (PCP) administration (10 mg kg(-1) daily for 14 days). Our results show that MSCs transplantation significantly prevented the PCP-induced social deficit, as assessed by the social preference test. In contrast, the PCP-induced social impairment was not modified by daily clozapine treatment. Tissue analysis revealed that the human MSCs survived in the mouse brain throughout the course of the experiment (23 days). Significantly increased cortical brain-derived neurotrophic factor levels were observed in the MSCs-treated group as compared with sham-operated controls. Furthermore, western blot analysis revealed that the ratio of phosphorylated Akt to Akt was significantly elevated in the MSCs-treated mice compared with the sham controls. Our results demonstrate that intracerebral transplantation of MSCs is beneficial in attenuating the social deficits induced by sub-chronic PCP administration. We suggest a novel therapeutic approach for the treatment of schizophrenia-like negative symptoms in animal models of the disorder.

The anti-inflammatory prostaglandin 15d-PGJ2 and its nuclear receptor PPARgamma are decreased in schizophrenia

A number of findings suggest that inflammation plays a role in the pathophysiology of schizophrenia. Taking into account a physiological balance between pro- and anti-inflammatory mediators, we measured the plasma levels of cyclooxygenase-derived mediators and other key pro- and anti-inflammatory transcription factors in peripheral blood mononuclear cells (PBMC). Forty healthy subjects and 46 treated chronic schizophrenic patients with an acutely exacerbated condition who met DSM-IV criteria were included. COX by-products prostaglandin E2 (PGE2) and 15d-prostaglandin J2 (15d-PGJ2) plasma levels were measured by EIA. Peroxisome proliferator-activated receptor gamma (PPARγ) as well as nuclear factor kappaB (NFκB) activity in nuclear extracts from PBMC and expression of its inhibitory subunit IκBα in cytosolic extracts were determined using ELISA-based kits. Schizophrenic patients showed higher plasma levels of pro-inflammatory PGE2 than age-matched controls (p=0.043). On the contrary, levels of anti-inflammatory 15-d-PGJ2 were lower (p=0.004), correlating with a lower expression of its nuclear target, PPARγ in nuclear extracts from PBMC (p=0.001). Although no changes in NFκB activity were observed between patients and healthy controls, the expression of its inhibitory protein IκBα was lower in the patients compared to the controls (p=0.027). These findings suggest that schizophrenia is associated with a systemic imbalance in the plasma levels of pro-inflammatory/anti-inflammatory prostaglandins in favor of the former. Furthermore, the expression and activity of anti-inflammatory PPARγ are diminished in PBMC, which indicates a state of inflammation and blunted anti-inflammatory counterbalancing mechanisms at systemic level in these patients.

Neuroimmune pharmacology of neurodegenerative and mental diseases

Neuroimmune pharmacology is a newly emerging field that intersects with neuroscience, immunology, and pharmacology and that is seeking avenues for translational research and better understanding of disease mechanisms. It focuses on the immunity of the central nervous system (CNS) which is greatly influenced by endogenous effectors, such as cytokines and neurotransmitters, and by exogenous substances, including therapeutic compounds, infectious pathogens, and drugs of abuse. In this article, we attempt to raise awareness of the pivotal discovery of how those mediators affect the immunity of the CNS in both physiological conditions and processes of certain mental illnesses, including psychiatric disorders, neurodegenerative diseases, and cerebral dysfunctions due to drugs of abuse. The abnormality in cytokine networks, neurotransmitter homeostasis, and other immune responses may be involved in the neuropathology associated with those mental illnesses, and the therapeutic effects of the potential treatments can be attributed, at least partially, to their immunomodulatory activities. However, the resulting inflammatory cytokines from certain treatments frequently cause psychiatric complications. In addition, the poor neuropathological outcomes frequently found among drug abusers with HIV-1 infection appear to be related to the neurotoxic and immunomodulatory effects of the drugs used. Importantly, glial cells, especially microglia and astrocytes, are key players in the immunomodulatory activities in the CNS, and the functioning CNS is largely dependent upon the reciprocal interactions between neurons and glial cells. Therefore, glia-neuron interactions have become a critical issue for further understanding the disease mechanism. From this review, readers will gain insights into the new field of neuroimmune pharmacology, with a focus on the impacts of CNS immunity on the mental illnesses.

Antidepressant pharmacotherapy: focus on sex differences in neuroimmunopharmacological crossroads

Major depression is a stress-related disorder that shows a clear female preponderance. Sex differences in antidepressant response have been documented in both the clinical and experimental settings. It is of interest that antidepressant drugs exert critical immunotropic influences, mediated by direct and/or compensatory routes; these effects are not completely understood but comprise a matter of intensive investigation. Even though human studies have found only a few sex-related differences in the immunotropic effects of antidepressants, recent experimental evidence in the chronic mild stress model of depression points towards a sexually dimorphic neuroimmune playground in view of chronic antidepressant treatment. Herein, we provide a concise review regarding the effects of antidepressant pharmacotherapy on neuroimmune manifestations by concentrating on intriguing sex differences.

Paroxetine prevents loss of nigrostriatal dopaminergic neurons by inhibiting brain inflammation and oxidative stress in an experimental model of Parkinson's disease

The present study examined whether the antidepressant paroxetine promotes the survival of nigrostriatal dopaminergic (DA) neurons in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. MPTP induced degeneration of nigrostriatal DA neurons and glial activation as visualized by tyrosine hydroxylase, macrophage Ag complex-1, and/or glial fibrillary acidic protein immunoreactivity. Real-time PCR, Western blotting, and immunohistochemistry showed upregulation of proinflammatory cytokines, activation of microglial NADPH oxidase and astroglial myeloperoxidase, and subsequent reactive oxygen species production and oxidative DNA damage in the MPTP-treated substantia nigra. Treatment with paroxetine prevented degeneration of nigrostriatal DA neurons, increased striatal dopamine levels, and improved motor function. This neuroprotection afforded by paroxetine was associated with the suppression of astroglial myeloperoxidase expression and/or NADPH oxidase-derived reactive oxygen species production and reduced expression of proinflammatory cytokines, including IL-1beta, TNF-alpha, and inducible NO synthase, by activated microglia. The present findings show that paroxetine may possess anti-inflammatory properties and inhibit glial activation-mediated oxidative stress, suggesting that paroxetine and its analogues may have therapeutic value in the treatment of aspects of Parkinson's disease related to neuroinflammation.

Anti-inflammatory effects of antidepressant and atypical antipsychotic medication for the treatment of major depression and comorbid arthritis: a case report

Introduction

This case report describes the effects of psychotropic treatment, quetiapine in particular, on systemic inflammation, pain, general functioning and major depression in the treatment of a woman with arthritis.

Case presentation

A 49-year-old Caucasian Australian woman with arthritis, pain and depression was treated with a course of escitalopram, mirtazapine and quetiapine. Pain levels, general functioning and degree of depressive symptoms were evaluated with a visual analogue scale. Systemic inflammation had been assessed by C-reactive protein serum levels since 2003. C-reactive protein levels, physical pain, symptoms of arthritis and depression decreased significantly during the past 12 months of treatment with quetiapine, while treatment with selective serotonin reuptake inhibitors and mirtazapine remained the same.

Conclusions

We suggest that the treatment particularly with quetiapine may have anti-inflammatory effects in arthritis and comorbid major depression, which eventually led to a remission of pain and depression and to normal general function.

A potential role for pro-inflammatory cytokines in regulating synaptic plasticity in major depressive disorder

A growing body of data suggests that hyperactivation of the immune system has been implicated in the pathophysiology of major depressive disorder (MDD). Several pro-inflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) have been found to be significantly increased in patients with MDD. This review focuses on these two cytokines based on multiple lines of evidence from genetic, animal behaviour, and clinical studies showing that altered levels of serum TNF-alpha and IL-1 are associated with increased risk of depression, cognitive impairments, and reduced responsiveness to treatment. In addition, recent findings have shown that centrally expressed TNF-alpha and IL-1 play a dual role in the regulation of synaptic plasticity. In this paper, we review and critically appraise the mechanisms by which cytokines regulate synaptic and neural plasticity, and their implications for the pathophysiology and treatment of MDD. Finally, we discuss the therapeutic potential of anti-inflammatory-based approaches for treating patients with severe mood disorders. This is a promising field for increasing our understanding of the mechanistic interaction between the immune system, synaptic plasticity, and antidepressants, and for the ultimate development of novel and improved therapeutics for severe mood disorders.