N-acetylcysteine modulates rotenone-induced mitochondrial Complex I dysfunction in THP-1 cells

Mitochondrial Complex I dysfunction and oxidative stress have been part of the pathophysiology of several diseases ranging from mitochondrial disease to chronic diseases such as diabetes, mood disorders and Parkinson's Disease. Nonetheless, to investigate the potential of mitochondria-targeted therapeutic strategies for these conditions, there is a need further our understanding on how cells respond and adapt in the presence of Complex I dysfunction. In this study, we used low doses of rotenone, a classical inhibitor of mitochondrial complex I, to mimic peripheral mitochondrial dysfunction in THP-1 cells, a human monocytic cell line, and explored the effects of N-acetylcysteine on preventing this rotenone-induced mitochondrial dysfunction. Our results show that in THP-1 cells, rotenone exposure led to increases in mitochondrial superoxide, levels of cell-free mitochondrial DNA, and protein levels of the NDUFS7 subunit. N-acetylcysteine (NAC) pre-treatment ameliorated the rotenone-induced increase of cell-free mitochondrial DNA and NDUFS7 protein levels, but not mitochondrial superoxide. Furthermore, rotenone exposure did not affect protein levels of the NDUFV1 subunit but induced NDUFV1 glutathionylation. In summary, NAC may help to mitigate the effects of rotenone on Complex I and preserve the normal function of mitochondria in THP-1 cells.

Optimization of differential filtration-based mitochondrial isolation for mitochondrial transplant to cerebral organoids

BACKGROUND

Mitochondrial dysfunction is involved in several diseases ranging from genetic mitochondrial disorders to chronic metabolic diseases. An emerging approach to potentially treat mitochondrial dysfunction is the transplantation of autologous live mitochondria to promote cell regeneration. We tested the differential filtration-based mitochondrial isolation protocol established by the McCully laboratory for use in cellular models but found whole cell contaminants in the mitochondrial isolate.

METHODS

Therefore, we explored alternative types of 5-μm filters (filters A and B) for isolation of mitochondria from multiple cell lines including HEK293 cells and induced pluripotent stem cells (iPSCs). MitoTracker™ staining combined with flow cytometry was used to quantify the concentration of viable mitochondria. A proof-of-principle mitochondrial transplant was performed using mitoDsRed2-tagged mitochondria into a H9-derived cerebral organoid.

RESULTS

We found that filter B provided the highest quality mitochondria as compared to the 5-μm filter used in the original protocol. Using this method, mitochondria were also successfully isolated from induced pluripotent stem cells. To test for viability, mitoDsRed2-tagged mitochondria were isolated and transplanted into H9-derived cerebral organoids and observed that mitochondria were engulfed as indicated by immunofluorescent co-localization of TOMM20 and MAP2.

CONCLUSIONS

Thus, use of filter B in a differential filtration approach is ideal for isolating pure and viable mitochondria from cells, allowing us to begin evaluating long-term integration and safety of mitochondrial transplant using cellular sources.

Measuring Brain Temperature in Youth Bipolar Disorder Using a Novel Magnetic Resonance Imaging Approach: A Proof-of-concept Study

BACKGROUND

There is evidence of alterations in mitochondrial energy metabolism and cerebral blood flow (CBF) in adults and youth with bipolar disorder (BD). Brain thermoregulation is based on the balance of heat-producing metabolism and heat-dissipating mechanisms, including CBF.

OBJECTIVE

To examine brain temperature, and its relation to CBF, in relation to BD and mood symptom severity in youth.

METHODS

This study included 25 youth participants (age 17.4 ± 1.7 years; 13 BD, 12 control group (CG)). Magnetic resonance spectroscopy data were acquired to obtain brain temperature in the left anterior cingulate cortex (ACC) and the left precuneus. Regional estimates of CBF were provided by arterial spin labeling imaging. Analyses used general linear regression models, covarying for age, sex, and psychiatric medications.

RESULTS

Brain temperature was significantly higher in BD compared to CG in the precuneus. A higher ratio of brain temperature to CBF was significantly associated with greater depression symptom severity in both the ACC and precuneus within BD. Analyses examining the relationship of brain temperature or CBF with depression severity score did not reveal any significant finding in the ACC or the precuneus.

CONCLUSION

The current study provides preliminary evidence of increased brain temperature in youth with BD, in whom reduced thermoregulatory capacity is putatively associated with depression symptom severity. Evaluation of brain temperature and CBF in conjunction may provide valuable insight beyond what can be gleaned by either metric alone. Larger prospective studies are warranted to further evaluate brain temperature and its association with CBF concerning BD.

Quantification of diet quality utilizing the rapid eating assessment for participants-shortened version in bipolar disorder: Implications for prospective depression and cardiometabolic studies

OBJECTIVES

Recognizing bipolar disorder as a multi-system metabolic condition driven, in part, by binge eating behavior and atypical depressive symptoms, this study aimed to quantify diet quality and evaluate clinical correlates in a bipolar disorder cohort.

METHODS

Participants from the Mayo Clinic Bipolar Disorder Biobank (n = 734) completed the Rapid Eating Assessment for Participants - Shortened version (REAP-S) to determine diet quality. The average REAP-S score for a U.S. omnivorous diet is 32 (range 13 to 39) with higher scores indicating healthier diet. Demographic variables were collected in a standardized clinical questionnaire. Depressive symptoms were assessed by the Bipolar Inventory of Symptoms Scale. Cardiometabolic variables were retrieved from the electronic health record. Associations between continuous variables and REAP-S scores (total, 'healthy foods' and 'avoidance of unhealthy foods') were assessed using linear regression.

RESULTS

Overall, our sample had a mean REAP-S score of 27.6 (4.9), suggestive of a lower diet quality than the average general population in the US. There was a significant inverse relationship between mean REAP-S lower scores with increased BMI, waist circumference, disordered eating and depression. All these associations were significantly stronger in female participants.

LIMITATIONS

EHR cross-sectional data.

CONCLUSIONS

Our data suggest unhealthy diet quality in bipolar disorder is associated with depression, obesity and cardiometabolic abnormalities. Additional work is encouraged to prospectively track mood and diet quality to further understand the bidirectional relationship and clarify if dietary interventions can positively impact mood. Further delineating potential sex differences in diet quality and depression may provide greater appreciation of modifiable risk factors for future cardiometabolic burden.

Açaí (Euterpe oleracea Mart.) as a Potential Anti-neuroinflammatory Agent: NLRP3 Priming and Activating Signal Pathway Modulation

Neurological disorders have been demonstrated to be associated with mitochondrial dysfunction. This impairment may lead to oxidative stress and neuroinflammation, specifically promoted by NLRP3 expression. Açaí (Euterpe oleracea Mart.) has been studied in this field, since it presents important biological activities. We investigated açaí extract's anti-neuroinflammatory capacity, through NLRP3 inflammasome modulation. Microglia (EOC 13.31) were exposed to LPS and nigericin, as agents of inflammatory induction, and treated with açaí extract. Additionally, we used lithium (Li) as an anti-inflammatory control. Three different experiment models were conducted: (1) isolated NLRP3 priming and activation signals; (2) combined NLRP3 priming and activation signals followed by açaí extract as a therapeutic agent; and (3) combined NLRP3 priming and activation signals with açaí extract as a preventive agent. Cells exposed to 0.1 µg/mL of LPS presented high proliferation and increased levels of NO, and ROS, while 0.1 µg/mL of açaí extract was capable to reduce cellular proliferation and recover levels of NO and ROS. Primed and activated cells presented increased levels of NLRP3, caspase-1, and IL-1β, while açaí, Li, and orientin treatments reversed this impairment. We found that açaí, Li, and orientin were effective prophylactic treatments. Preventative treatment with Li and orientin was unable to avoid overexpression of IL-1β compared to the positive control. However, orientin downregulated NLRP3 and caspase-1. Lastly, primed and activated cells impaired ATP production, which was prevented by pre-treatment with açaí, Li, and orientin. In conclusion, we suggest that açaí could be a potential agent to treat or prevent neuropsychiatric diseases related to neuroinflammation.

Effect of neuropsychiatric medications on mitochondrial function: For better or for worse

Individuals with mitochondrial disease often present with psychopathological comorbidity, and mitochondrial dysfunction has been proposed as the underlying pathobiology in various psychiatric disorders. Several studies have suggested that medications used to treat neuropsychiatric disorders could directly influence mitochondrial function. This review provides a comprehensive overview of the effect of these medications on mitochondrial function. We collected preclinical information on six major groups of antidepressants and other neuropsychiatric medications and found that the majority of these medications either positively influenced mitochondrial function or showed mixed effects. Only amitriptyline, escitalopram, and haloperidol were identified as having exclusively adverse effects on mitochondrial function. In the absence of formal clinical trials, and until such trials are completed, the data from preclinical studies reported and discussed here could inform medication prescribing practices for individuals with psychopathology and impaired mitochondrial function in the underlying pathology.

Açaí (Euterpe oleracea Mart.) presents anti-neuroinflammatory capacity in LPS-activated microglia cells

INTRODUCTION

Neuropsychiatric diseases are responsible for one of the highest burden of morbidity and mortality worldwide. These illnesses include schizophrenia, bipolar disorder, and major depression. Individuals affected by these diseases may present mitochondrial dysfunction and oxidative stress. Additionally, patients also have increased peripheral and neural chronic inflammation. The Brazilian fruit, açaí, has been demonstrated to be a neuroprotective agent through its recovery of mitochondrial complex I activity. This extract has previously shown anti-inflammatory effects in inflammatory cells. However, there is a lack of understanding of potential anti-neuroinflammatory mechanisms, such as cell cycle involvement.

OBJECTIVE

The objective of this study is to evaluate the anti-neuroinflammatory potential of an açaí extract in lipopolysaccharide-activated BV-2 microglia cells.

METHODS

Açaí extract was produced and characterized through high performance liquid chromatography. Following açaí extraction and characterization, BV-2 microglia cells were activated with LPS and a dose-response curve was generated to select the most effective açaí dose to reduce cellular proliferation. This dose was then used to assess reactive oxygen species (ROS) production, double-strand DNA release, cell cycle modulation, and cytokine and caspase protein expression.

RESULTS

Characterization of the açaí extract revealed 10 bioactive molecules. The extract reduced cellular proliferation, ROS production, and reduced pro-inflammatory cytokines and caspase 1 protein expression under 1 μg/mL in LPS-activated BV-2 microglia cells but had no effect on double strand DNA release. Additionally, açaí treatment caused cell cycle arrest, specifically within synthesis and G2/Mitosis phases.

CONCLUSION

These results suggest that the freeze-dried hydroalcoholic açaí extract presents high anti-neuroinflammatory potential.

Mitochondrial DNA content and oxidation in bipolar disorder and its role across brain regions

The underlying pathology of bipolar disorder remains unknown, though evidence is accumulating to support a role of mitochondrial dysfunction. In this study, we aim to investigate electron transport chain complex I subunit NDUFS7 protein expression; mtDNA content; common deletion; and oxidation in the Broadmann area 24 (BA24), cerebellum, hippocampus, and prefrontal cortex from patients with bipolar disorder, schizophrenia, and non-psychiatric controls. Here, we demonstrate no changes in NDUFS7 in BA24, cerebellum or hippocampus, increases in mtDNA content in hippocampus of patients with bipolar disorder, and decreases in mtDNA oxidation in patients with bipolar disorder and schizophrenia, respectively. Paired analysis between BA24 and cerebellum reveal increases within NDUFS7 levels and mtDNA content in cerebellum of patients with bipolar disorder or schizophrenia. We found a positive correlation between NDUFS7 and mtDNA content (ND4 and ND5) when combining brain regions. Our study supports the involvement of mitochondrial dysfunction in bipolar disorder and schizophrenia.

Araucaria angustifolia (Bertol.) Kuntze has neuroprotective action through mitochondrial modulation in dopaminergic SH-SY5Y cells

Brain disorders (BD) including neuropsychiatric and neurodegenerative diseases, are often associated with impairments in mitochondrial function and oxidative damage that can lead to neuronal injury. The mitochondrial complex I enzyme is one of the main sites of ROS generation and is implicated in many BD pathophysiologies. Despite advances in therapeutics for BD management, conventional pharmacotherapy still cannot efficiently control neuronal redox imbalance and mitochondrial dysfunction. Araucaria angustifolia is one of the main pine species in South America and presents a notable therapeutic history in folk medicine. A. angustifolia extract (AAE), obtained from the natural waste named bracts, is rich in flavonoids; molecules able to regulate cell redox metabolism. We examined the effects of AAE on rotenone-induced mitochondrial complex I dysfunction in human dopaminergic SH-SY5Y cells. AAE restored complex I assembly and activity mainly through overexpression of NDUFS7 protein and NDUFV2 gene levels. These findings were accompanied by a reduction in the generation of neuronal reactive oxygen species and lipid peroxidation. Our data demonstrates, for the first time, that AAE exerts in vitro neuroprotective effects, thus making it an interesting source for future drug development in BD-associated mitochondrial dysfunctions.

Upstream Pathways Controlling Mitochondrial Function in Major Psychosis: A Focus on Bipolar Disorder

Mitochondrial dysfunction is commonly observed in bipolar disorder (BD) and schizophrenia (SCZ) and may be a central feature of psychosis. These illnesses are complex and heterogeneous, which is reflected by the complexity of the processes regulating mitochondrial function. Mitochondria are typically associated with energy production; however, dysfunction of mitochondria affects not only energy production but also vital cellular processes, including the formation of reactive oxygen species, cell cycle and survival, intracellular Ca(2+) homeostasis, and neurotransmission. In this review, we characterize the upstream components controlling mitochondrial function, including 1) mutations in nuclear and mitochondrial DNA, 2) mitochondrial dynamics, and 3) intracellular Ca(2+) homeostasis. Characterizing and understanding the upstream factors that regulate mitochondrial function is essential to understand progression of these illnesses and develop biomarkers and therapeutics.

Oxidative stress in older patients with bipolar disorder

OBJECTIVE

Increases in oxidative stress have been consistently reported in younger patients with bipolar disorder (BD) in postmortem brain and blood samples studies. Changes in oxidative stress are also associated with the natural aging process. Thus, the investigation of oxidative stress across the life span of patients with BD is crucial.

METHODS

We compared the levels of oxidative damage to proteins and lipids in plasma from 110 euthymic older patients with BD I or II (mean±SD age: 63.9±9.7 years) and 75 older healthy individuals (66.0±9.6 years). To assess protein oxidation, we measured the plasma levels of protein carbonyl (PC) and 3-nitrotyrosine (3-NT) using the ELISA technique. To assess lipid peroxidation, we measured plasma levels of lipid hydroperoxide (LPH) and 4-hydroxynonenal (4-HNE) using spectrophotometric assays.

RESULTS

LPH levels were higher in patients than in the comparison healthy individuals, whereas there were no significant differences for PC, 3-NT, and 4-HNE between the two groups.

CONCLUSIONS

The increased levels of an early component of the peroxidation chain (LPH) in euthymic older patients with BD support the hypothesis of a persistent effect of reactive species of oxygen in patients with BD into late life.

The role of neurotrophins in bipolar disorder

Bipolar disorder (BD) is a chronic psychiatric illness of which the pathophysiology remains partially unknown. Abnormalities of neurotrophins and other trophic factors orchestrate important alterations which could be implicated in the etiology of BD. Therefore, the main objective of this review is to examine the recent findings and critically evaluate the potential role of neurotrophins that may allow us to substantially improve the development of novel treatments. The most recently published findings highlight that brain-derived neurotrophic factor (BDNF), insulin-like growth factor (IGF-1) and vascular endothelial growth factor (VEGF) present distinct patterns in the different stages of BD, suggesting their potential in the identification of the BD subgroups and may ultimately advance treatment strategies.

Current state of biomarkers in bipolar disorder

Bipolar disorder (BD) is a chronic psychiatric illness of which the etiology remains unknown. Extensive research has provided some hypotheses for the pathophysiology of this disorder; however, there are no molecular tests available to help support the diagnosis obtained by self-report and behavioral observations. A major requirement is to identify potential biomarkers that could be used for early diagnosis in patients susceptible to the disease and for its treatment. The most recently published findings regarding alterations in BD were found to be related to oxidative stress, inflammatory and trophic factor deregulation, and also polymorphisms of genes that are associated with the development of BD. Many of these targets are potential biomarkers which could help to identify the BD subgroups and to advance treatment strategies, which would beneficiate the quality of life of these patients. Therefore, the main objective of this review is to examine the recent findings and critically evaluate their potential as biomarkers for BD.

Oxidation and nitration in dopaminergic areas of the prefrontal cortex from patients with bipolar disorder and schizophrenia

BACKGROUND

Increased oxidative stress is strongly implicated in bipolar disorder (BD), where protein oxidation, lipid peroxidation and oxidative damage to DNA have been consistently reported. High levels of dopamine (DA) in mania are also well-recognized in patients with BD, and DA produces reactive oxygen species and electron-deficient quinones that can oxidize proteins when it is metabolized.

METHODS

Using immunohistochemistry and acceptor photobleaching Förster resonance energy transfer (FRET), we examined oxidation and nitration of areas immunoreactive for the DA transporter (DAT) and tyrosine hydroxylase (TH) in the postmortem prefrontal cortex from patients with BD, schizophrenia and major depression as well as nonpsychiatric controls.

RESULTS

We found increased oxidation of DAT-immunoreactive regions in patients with BD (F3,48 = 6.76, p = 0.001; Dunnett post hoc test p = 0.001) and decreased nitration of TH-immunoreactive regions in both patients with BD (F3,45 = 3.10, p = 0.036; Dunnett post hoc test p = 0.011) and schizophrenia (p = 0.027). On the other hand, we found increased global levels of oxidation in patients with BD (F3,44 = 6.74, p = 0.001; Dunnett post hoc test p = 0.001) and schizophrenia (p = 0.020), although nitration levels did not differ between the groups (F3,46 = 1.75; p = 0.17).

LIMITATIONS

Limitations of this study include the use of postmortem brain sections, which may have been affected by factors such as postmortem interval and antemortem agonal states, although demographic factors and postmortem interval were accounted for in our statistical analysis.

CONCLUSION

These findings suggest alterations in levels of protein oxidation and nitration in DA-rich regions of the prefrontal cortex in patients with BD and schizophrenia, but more markedly in those with BD.

Elevated serum measures of lipid peroxidation and abnormal prefrontal white matter in euthymic bipolar adults: toward peripheral biomarkers of bipolar disorder

Diffusion tensor imaging (DTI) studies consistently reported abnormalities in fractional anisotropy (FA) and radial diffusivity (RD), measures of the integrity of white matter (WM), in bipolar disorder (BD), that may reflect underlying pathophysiologic processes. There is, however, a pressing need to identify peripheral measures that are related to these WM measures, to help identify easily obtainable peripheral biomarkers of BD. Given the high lipid content of axonal membranes and myelin sheaths, and that elevated serum levels of lipid peroxidation are reported in BD, these serum measures may be promising peripheral biomarkers of underlying WM abnormalities in BD. We used DTI and probabilistic tractography to compare FA and RD in ten prefrontal-centered WM tracts, 8 of which are consistently shown to have abnormal FA (and/or RD) in BD, and also examined serum lipid peroxidation (lipid hydroperoxides, LPH and 4-hydroxy-2-nonenal, 4-HNE), in 24 currently euthymic BD adults (BDE) and 19 age- and gender-matched healthy adults (CONT). There was a significant effect of group upon FA in these a priori WM tracts (BDECONT: F[1,41]=10.3; P=0.003), and a significant between-group difference in LPH (BDE>CONT: t[40]=2.4; P=0.022), but not in 4-HNE. Multivariate multiple regression analyses revealed that LPH variance explained, respectively, 59 and 51% of the variance of FA and RD across all study participants. This is the first study to examine relationships between measures of WM integrity and peripheral measures of lipid peroxidation. Our findings suggest that serum LPH may be useful in the development of a clinically relevant, yet easily obtainable and inexpensive, peripheral biomarkers of BD.

Combining redox-proteomics and epigenomics to explain the involvement of oxidative stress in psychiatric disorders

Psychiatric disorders affect approximately 10% of adults in North-America. The complex nature of these illnesses makes the search for their pathophysiology a challenge. However, studies have consistently shown that mitochondrial dysfunction and oxidative stress are common features across major psychiatric disorders, including bipolar disorder and schizophrenia. Nevertheless, little is known about specific targets of oxidation in the brain. The search for redox sensors (protein targets for oxidation) will offer information about which pathways are regulated by oxidation in psychiatric disorders. Additionally, DNA is also a target for oxidative damage and recently, studies have suggested that oxidation of cytosine and guanosine can serve as an epigenetic modulator by decreasing or preventing further DNA methylation. Therefore, this review aims to discuss how we can use redox-proteomics and epigenomics to help explain the role of oxidative damage in major psychiatric disorders, which may ultimately lead to the identification of targets for development of new medications.

The relationship between oxidative stress and post-translational modification of the dopamine transporter in bipolar disorder

Bipolar disorder (BD) has been consistently associated with altered levels of oxidative stress markers, although the cause and consequences of these alterations remain to be elucidated. One of the main hypotheses regarding the pathogenesis of mania involves increased dopaminergic transmission. In this review, the authors aim to discuss a potential mechanism by which increased oxidative stress inhibits the uptake of dopamine through the post-translational modification of the dopamine transporter and its implications for BD. Within the next 5 years, the authors believe that the mechanisms of dopamine transporter oxidation and its impact on the pathophysiology of BD will be elucidated, which may open avenues for the development of more specific interventions for the treatment of this debilitating illness.

Plasma cortisol in first episode drug-naïve mania: differential levels in euphoric versus irritable mood

BACKGROUND

Dysregulation of HPA axis has been widely described in subjects with bipolar disorder (BD), including changes in cortisol levels during mood episodes and euthymia. However, most of the studies were done with medicated BD patients with variable length of illness, which was shown to interfere on peripheral cortisol levels. Therefore, the present study aims to evaluate plasma cortisol levels in drug-naïve BD subjects during the first manic episode, as well as investigate the relationship between plasma cortisol levels and manic symptomatology.

METHODS

Twenty-six drug-naïve patients were enrolled meeting criteria for a first manic episode in bipolar I disorder. Severity of mania was assessed using the Young Mania Rating Scale (YMRS). The control group included 27 healthy subjects matched by age and gender. Cortisol was quantified using a direct radioimmunoassay.

RESULTS

Plasma cortisol levels were decreased during first manic episode compared to healthy controls. Higher cortisol levels were positively associated with the presence of irritability (dysphoria), while elated mania showed lower cortisol levels compared to controls.

LIMITATION

Data including larger samples are lacking.

CONCLUSION

Higher cortisol in dysphoric mania compared to predominantly elated/euphoric mania may indicate a clinical and neurobiological polymorphic phenomenon, potentially involving a higher biological sensitivity to stress in the presence of irritable mood. The present findings highlight the importance to add a dimensional approach to the traditional categorical diagnosis for future neurobiological studies in BD.

Pathways underlying neuroprogression in bipolar disorder: focus on inflammation, oxidative stress and neurotrophic factors

There is now strong evidence of progressive neuropathological processes in bipolar disorder (BD). On this basis, the current understanding of the neurobiology of BD has shifted from an initial focus on monoamines, subsequently including evidence of changes in intracellular second messenger systems and more recently to, incorporating changes in inflammatory cytokines, corticosteroids, neurotrophins, mitochondrial energy generation, oxidative stress and neurogenesis into a more comprehensive model capable of explaining some of the clinical features of BD. These features include progressive shortening of the inter-episode interval with each recurrence, occurring in consort with reduced probability of treatment response as the illness progresses. To this end, emerging data shows that these biomarkers may differ between early and late stages of BD in parallel with stage-related structural and neurocognitive alterations. This understanding facilitates identification of rational therapeutic targets, and the development of novel treatment classes. Additionally, these pathways provide a cogent explanation for the efficacy of seemingly diverse therapies used in BD, that appear to share common effects on oxidative, inflammatory and neurotrophic pathways.

Cognitive function and serum levels of brain-derived neurotrophic factor in patients with bipolar disorder

OBJECTIVES

Brain-derived neurotrophic factor (BDNF) is an important contributor to the pathophysiology of bipolar disorder (BD), and abnormalities in the BDNF-signaling system may be implicated in the cognitive decline observed in BD patients. We aimed to investigate serum BDNF levels in BD patients and its relation to neurocognitive function.

METHODS

We measured serum BDNF levels using an enzyme-linked immunosorbent assay method in 65 euthymic type I BD patients and 50 healthy controls, and administered a neuropsychological test battery to assess attention and mental control, perceptual-motor skills, executive functions, verbal fluency and abstraction, visuospatial attention, and memory.

RESULTS

We found no significant differences regarding serum BDNF levels in BD patients and healthy controls. We found significant positive associations between serum BDNF levels and illness duration, and manic and depressive episodes in female BD patients only. Serum BDNF levels were lower in patients medicated with antipsychotics and/or lithium, whereas patients on valproate and/or antidepressants showed higher serum BDNF levels. Patients performed significantly worse on 11 out of 16 neurocognitive tests as compared to controls. We found a significant positive association between serum BDNF levels and a test of verbal fluency in both BD patients and controls.

CONCLUSIONS

Present results support the hypothesis that BDNF normalizes with mood stabilization and pharmacological treatment. Our findings in young and physically healthy patients with short illness duration and few mood episodes may explain the lack of association between serum BDNF levels and neurocognitive performance, even though cognitive performance in patients was overall significantly worse as compared to healthy controls.

3-Nitrotyrosine and glutathione antioxidant system in patients in the early and late stages of bipolar disorder

BACKGROUND

There has been an increasing interest in the role of oxidative stress in the pathophysiology of bipolar disorder. To explore this further, we evaluated the activity of glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), as well as 3-nitrotyrosine levels and carbonyl content in patients in the early (within 3 years of illness onset) and late (a minimum of 10 years of illness) stages of bipolar disorder.

METHODS

We matched 30 patients in the early stage and 30 patients in the late stage of bipolar disorder, diagnosed according to DSM-IV criteria, with 60 healthy controls (30 matched for each group of patients). We measured symptomatic status using the Hamilton Rating Scale for Depression and the Young Mania Rating Scale.

RESULTS

We found a significant increase in 3-nitrotyrosine levels among patients in the early (p < 0.010) and late (p < 0.010) stages of bipolar disorder. The activity of GR and GST was increased only among patients in the late stage of illness. Glutathione peroxidase activity and carbonyl content did not differ among the groups.

LIMITATIONS

Limitations of our study include its cross-sectional design, which did not allow us to examine direct causative mechanisms or the effects of progression of illness, and the potential environmental bias introduced by comparing patient groups recruited from different regions of the world.

CONCLUSION

Our data indicate a possible tyrosine nitration-induced damage in patients with bipolar disorder that is present from the early stage of illness. Our data also indicate that patients in the late stage of illness demonstrate enhanced activity of GR and GST, which could suggest the involvement of a compensatory system in bipolar disorder.

Serum levels of brain-derived neurotrophic factor and thiobarbituric acid reactive substances in chronically medicated schizophrenic patients: a positive correlation

OBJECTIVE

The neurotrophins, antioxidant enzymes and oxidative markers have reciprocal interactions. This report verified in chronically stable medicated schizophrenic patients whether there are correlations between the serum levels of superoxide dismutase, a key enzyme in the antioxidant defense, thiobarbituric acid reactive substances, a direct index of lipid peroxidation, and brain-derived neurotrophic factor, the most widely distributed neurotrophin.

METHOD

Sixty DSM-IV schizophrenic patients were included (43 males, 17 females). Mean age was 34.7 +/- 10.8 years, mean age at first episode was 19.8 +/- 7.9 years, and mean illness duration was 14.9 +/- 8.5 years. Each subject had a blood sample collected for the determination of serum levels of brain-derived neurotrophic factor, thiobarbituric acid reactive substances and superoxide dismutase.

RESULTS

Brain-derived neurotrophic factor levels showed a positive correlation with thiobarbituric acid reactive substances levels (r = 0.333, p = 0.009). Brain-derived neurotrophic factor levels were not correlated with superoxide dismutase levels (r = - 0.181, p = 0.166), and superoxide dismutase levels were not correlated with thiobarbituric acid reactive substances levels (r = 0.141, p = 0.284).

CONCLUSIONS

The positive correlation between brain-derived neurotrophic factor and thiobarbituric acid reactive substances suggests the need of further investigation on intracellular interactions of neurotrophins, antioxidant enzymes and oxidative markers. In addition, this opens a venue for investigation on treatments for the prevention of neurotoxicity along the course of schizophrenia.

Early intervention in bipolar disorders: clinical, biochemical and neuroimaging imperatives

In the absence of clear targets for primary prevention of many psychiatric illnesses, secondary prevention becomes the most feasible therapeutic target, and is best encompassed by the concept of early intervention. This construct encompasses the goals of minimising diagnostic delay and the prompt initiation of clinically appropriate therapy. This paper develops the rationale for early intervention in bipolar disorder. Three interrelated themes are discussed; the clinical data supporting the value of prompt diagnosis and treatment in bipolar disorder, the putative biochemical mechanisms underlying the pathophysiological processes, and the parallel concept of neuroprotection, and the developing neuroimaging data that supports early intervention. Early initiation of appropriate therapy may potentially facilitate improved clinical outcomes, and further might allow the secondary prevention of the sequelae of untreated illness, which include the deleterious impact on family relationships, psychosexual and vocational development, identity and self-concept and self-stigma.

Chronic administration of ketamine elicits antidepressant-like effects in rats without affecting hippocampal brain-derived neurotrophic factor protein levels

A growing body of evidence has pointed to the blockade of the N-methyl-d-aspartate (NMDA) receptor signaling as a potential therapeutic target for the treatment of major depression. The present study was aimed to evaluate behavioural and molecular effects of the chronic treatment with ketamine and imipramine in rats. To this aim, rats were 14 days treated once a day with ketamine (5, 10 and 15 mg/kg) and imipramine (10, 20 and 30 mg/kg) and then subjected to the forced swimming and open-field tests. Ketamine and imipramine, at the all doses tested, reduced immobility time, and increased both climbing and swimming time of rats compared to the saline group, without affecting spontaneous locomotor activity. Brain-derived neurotrophic factor (BDNF) hippocampal levels were assessed in imipramine- and ketamine-treated rats by ELISA sandwich assay. Chronic administration of both drugs, ketamine and imipramine, did not modify BDNF protein levels in the rat hippocampus. In conclusion, our findings demonstrate for the first time that chronic administration of acute inactive doses of ketamine (5 mg/kg) becomes active after chronic treatment, while no signs of tolerance to the behavioural effects of ketamine were observed after chronic administration of acute active doses (10 and 15 mg/kg). Finally, these findings further support the hypothesis that NMDA receptor could be a new pharmacological target for the treatment of mood disorders.

Effects of mood stabilizers on DNA damage in an animal model of mania

OBJECTIVE

Recent studies have suggested that oxidative stress and DNA damage may play a role in the pathophysiology of bipolar disorder (BD). We investigated the effects of the mood stabilizers lithium and valproate on amphetamine-induced DNA damage in an animal model of mania and their correlation with oxidative stress markers.

METHODS

In the first experiment (reversal model), we treated adult male Wistar rats with D-amphetamine (AMPH) or saline for 14 days; between the 8th and 14th days, rats also received lithium, valproate or saline. In the second experiment (prevention model), rats received either lithium, valproate or saline for 14 days; between the 8th and 14th days, we added AMPH or saline. We evaluated DNA damage using single-cell gel electrophoresis (comet assay), and we assessed the mutagenic potential using the micronucleus test. We assessed oxidative stress levels by lipid peroxidation levels (TBARS) and antioxidant enzyme activities (superoxide dismutase and catalase). We assessed DNA damage and oxidative stress markers in blood/plasma and hippocampal samples. We evaluated mutagenesis in fresh lymphocytes.

RESULTS

In both models, we found that AMPH increased peripheral and hippocampal DNA damage. The index of DNA damage correlated positively with lipid peroxidation, whereas lithium and valproate were able to modulate the oxidative balance and prevent recent damage to the DNA. However, lithium and valproate were not able to prevent micronucleus formation.

CONCLUSION

Our results support the notion that lithium and valproate exert central and peripheral antioxidant-like properties. In addition, the protection to the integrity of DNA conferred by lithium seems to be limited to transient DNA damage and does not alter micronuclei formation.

Elevated serum superoxide dismutase and thiobarbituric acid reactive substances in different phases of bipolar disorder and in schizophrenia

There is an increasing body of evidence suggesting that oxidative stress may play a role in the pathophysiology of both schizophrenia (SZ) and bipolar disorder (BD).

METHODS

We compared the antioxidant enzyme, serum superoxide dismutase (SOD) and the lipid peroxidation product, thiobarbituric acid reactive substances (TBARS) as assessed in depressed (N=21), manic (N=32) and euthymic (N=31) bipolar patients, and in chronically medicated patients with schizophrenia (N=97), all fulfilling DSM-IV diagnostic criteria, and a group of healthy controls (N=32).

RESULTS

Serum SOD (U/mg protein) activity was significantly increased (p<0.001) in manic (7.44+/-3.88) and depressed (6.12+/-4.64) BD patients and SZ (9.48+/-4.51) when compared to either controls (1.81+/-0.63) or euthymic (2.75+/-1.09) BD patients. TBARS (mol/L) levels were significantly higher in the SZ group (4.95+/-1.56, p=0.016), bipolar euthymic (6.36+/-1.46, p<0.001), bipolar manic (7.54+/-1.74, p<0.001), and bipolar depressed patients (5.28+/-1.54, p=0.028) compared to controls (3.96+/-1.51).

DISCUSSION

Our findings show increased SOD activity in SZ, as well as in depressed and manic bipolar patients, but not in euthymic BD subjects. This suggests a dysregulation in oxidative defenses in both disorders. It is likely that such changes reflect state changes in bipolar disorder. It is possible that this is a compensatory response to the oxidative stress that occurs in the acute phase of bipolar episodes. TBARS results show increases in lipid peroxidation in mania. TBARS levels in SZ and in euthymic as well as depressed individuals with BD were higher than in controls. This suggests persistent increases in SZ, which may reflect ongoing symptomatology or treatment, and a state dependent gradient in BD, with greatest oxidative stress in mania. These data support oxidative biology as both a key component of the pathophysiology of both BD and SZ, and the use of agents that modulate oxidative biology as a promising avenue for intervention in both disorders.

Serum levels of brain-derived neurotrophic factor in schizophrenia on a hypocaloric diet

Dietary factors influence BDNF in animal studies, but there is no comparable data in clinical populations. We examined the effect of a dietary intervention on BDNF serum levels in 67 DSM-IV schizophrenic outpatients (51 males and 16 females). Two groups were assessed in a cross-sectional study: one on a hypocaloric diet (HD) and the other not on a hypocaloric diet. Weight, height and BMI data were collected concurrently with 5-ml blood sampling of each subject. BDNF levels were measured with a sandwich-ELISA. The blood sample was obtained a minimum of one month after the exposure to dietary intervention. Serum BDNF levels were significantly higher in patients on the HD (p=0.023). Additional research examining the interaction among patterns of nutritional food behavior and underlying physiopathology may result in insights upon which evidence-based decisions regarding dietary interventions can be made in people identified with major psychiatric disorders, such as schizophrenia.

Evaluation of genetic damage in a Brazilian population occupationally exposed to pesticides and its correlation with polymorphisms in metabolizing genes

Cytogenetic damage in individuals occupationally exposed to pesticides has received the attention of investigators in several countries, but no definitive conclusions can yet be made. The present study aimed at assessing if prolonged exposure to complex mixtures of pesticides leads to an increase in cytogenetic damage. Vineyard workers exposed to pesticides in Caxias do Sul (Brazil) were evaluated using the micronucleus (MN) test in binucleated lymphocytes and the comet assay in peripheral leukocytes. In order to evaluate if genetically determined individual variations in xenobiotic metabolizing capacity could modify individual susceptibility to the possible genotoxic effects of pesticides, the subjects were genotyped for several genes: GSTT1, GSTM1, GSTP1, CYP1A1, CYP2E1 and PON. The study involved a total number of 173 men: 108 were agricultural workers exposed to pesticides and 65 were controls. The present study showed a high rate of MN and DNA damage in pesticide-exposed individuals (P <or= 0.001; Mann-Whitney U-test). In addition, some effects of genetic polymorphisms in PON in the modulation of MN results were observed in the exposed group, and an association between GSTM1, GSTT1 and CYP2E1 polymorphisms was suggested.

Emotional memory in bipolar disorder

BACKGROUND

Cognitive impairment has been well documented in bipolar disorder. However, specific aspects of cognition such as emotional memory have not been examined.

AIMS

To investigate episodic emotional memory in bipolar disorder, as indicated by performance on an amygdala-related cognitive task.

METHOD

Twenty euthymic patients with bipolar disorder and 20 matched controls were recruited. Participants were shown a slide show of an emotionally neutral story, or a closely matched emotionally arousing story. One week later, participants were assessed on a memory-recall test.

RESULTS

In contrast with the pattern observed in controls, patients with bipolar disorder had no enhancement of memory for the emotional content of the story (F=14.7, d.f.=1,36, P<0.001). The subjective perception of the emotional impact of the emotional condition was significantly different from that of the neutral condition in controls but not in people with bipolar disorder.

CONCLUSIONS

Our data suggest that the physiological pattern of enhanced memory retrieval for emotionally bound information is blunted in bipolar disorder.

Predominant polarity in bipolar disorder: diagnostic implications

BACKGROUND

It has been reported that patients with bipolar disorder (BD) remain about 10 years symptomatic before the correct diagnosis is made. This fact is particularly important for patients with predominantly depressed polarity who tend to be diagnosed as suffering from unipolar major depressive disorder and treated with antidepressants. The present study was carried out to assess clinical differences between predominantly manic and depressed BD patients with a special focus on the time that patients remained undiagnosed.

METHODS

Clinical and socio-demographic characteristics were obtained from a sample of 149 euthymic bipolar outpatients. Patients were divided into depressive or manic predominance of polarity. Clinical features, number of years undiagnosed (NYU) and occupational functioning were assessed in the two groups.

RESULTS

Forty-five patients were classified as a "Depressive Polarity" whilst forty-seven were considered as "Manic Polarity". Depressive Polarity was associated with a longer delay to be diagnosed (F=14.43, df=89, p=0.001). The predominantly depressive patients tended to present a depressive onset of illness, earlier age of onset, longer duration of illness and higher number of suicide attempts than manic polarity patients.

CONCLUSION

There was a marked clinical difference between predominantly manic and depressive bipolar patients. Predominantly depressive polarity is associated with a longer delay in receiving a correct diagnosis and effective treatment which has an important impact on the management of the illness.

Acute administration of ketamine induces antidepressant-like effects in the forced swimming test and increases BDNF levels in the rat hippocampus

Ketamine is a non-competitive antagonist to the phencyclidine site of N-methyl-d-aspartate (NMDA) receptor. Clinical findings point to a rapid onset of action for ketamine on the treatment of major depression. Considering that classic antidepressants may take long-lasting time to exhibit their main therapeutic effects, the present study aims to compare the behavioral effects and the BDNF hippocampus levels of acute administration of ketamine and imipramine in rats. To this aim, rats were acutely treated with ketamine (5, 10 and 15 mg/kg) and imipramine (10, 20 and 30 mg/kg) and animal behavioral was assessed in the forced swimming and open-field tests. Afterwards, BDNF protein hippocampal levels were assessed in imipramine- and ketamine-treated rats by ELISA-sandwich assay. We observed that ketamine at the doses of 10 and 15 mg/kg, and imipramine at 20 and 30 mg/kg reduced immobility time compared to saline group, without affecting locomotor activity. Interesting enough, acute administration of ketamine at the higher dose, but not imipramine, increased BDNF protein levels in the rat hippocampus. In conclusion, our findings suggest that the increase of hippocampal BDNF protein levels induced by ketamine might be necessary to produce a rapid onset of antidepressant action.

Mismatch between self-reported quality of life and functional assessment in acute mania: a matter of unawareness of illness?

BACKGROUND

Studies addressing self-reported quality of life (QoL) in acute mania are scarce and inconsistent. While it has been suggested that there is some disagreement between objective measures and subjective QoL as reported by acutely manic patients, this issue has not been systematically studied. This study aims to investigate the self-reported QoL in manic, depressed, and euthymic BD subjects, as compared to matched healthy controls.

METHODS

One-hundred and twenty type-I bipolar patients (40 manic, 40 depressed, and 40 euthymic) and 40 matched controls were studied. Self-reported QoL was assessed using the World Health Organization's Quality of Life Instrument-Short Version (WHOQOL-BREF). Objective functioning was assessed using the Global Assessment of Functioning (GAF), and depressive and manic symptoms were assessed using the Hamilton Depression Rating Scale-17 items (HDRS) and the Young Mania Rating Scale (YMRS), respectively.

RESULTS

Manic patients presented the lowest GAF measures but reported same overall QoL as euthymic patients and controls, and better QoL than depressed patients. Within the manic subgroup, there was a significant inverse correlation between psychological QoL and GAF scores (r=-0.54; p=0.001).

LIMITATIONS

The cross-sectional design and the lack of control for potential comorbid conditions are the major limitations of the present study.

CONCLUSIONS

Our findings suggest that this mismatch between objective and subjective measures during acute mania may be associated with a lack of insight or awareness of their own illness.

DNA damage in bipolar disorder

Bipolar disorder (BD) is a prevalent, chronic, severe, and highly disabling psychiatric disorder that is associated with increased morbidity and mortality due to general medical conditions. There is an emerging body of evidence correlating chronic medical conditions with DNA damage. The present study was designed to assess DNA damage in BD patients using the comet assay (CA). Thirty-two bipolar-I outpatients diagnosed using the Structured Clinical Interview for DSM-IV were matched with 32 healthy volunteers. Manic and depressive symptoms were assessed using the Young Mania Rating Scale and the Hamilton Depression Rating Scale, respectively. Peripheral blood samples were collected and a standard protocol for CA preparation and analysis was performed. The present study showed that BD outpatients present an increased frequency of DNA damage relative to controls. The frequency of DNA damage correlated with the severity of symptoms of depression and mania.

Manic symptoms and quality of life in bipolar disorder

This study evaluates the influence of manic symptoms on quality of life in a sample of adult bipolar disorder (BD) patients. This was a cross-sectional study including 125 BD outpatients from a university-based program. All patients were diagnosed using the Structured Clinical Interview for DSM-IV for BD. Manic symptoms and quality of life were assessed using the Young Mania Rating Scale (YMRS) and the World Health Organization Quality of Life Instrument-Short Version (WHOQOL-BREF), respectively. In the unadjusted analysis using linear regression, the score of manic symptoms was inversely associated with scores of quality of life within the social domain of the WHOQOL. In the adjusted analysis, the score of manic symptoms was inversely associated with the social, physical, and psychological domains of the WHOQOL. In a separate analysis at the YMRS items, items 4 (irritability) and 5 (sleep) were associated with lower quality of life.

Serum S100B and antioxidant enzymes in bipolar patients

Bipolar disorder (BD) is a chronic, severe, and highly disabling psychiatric disorder; peripheral markers have been used to assess biochemical alterations associated with BD and/or possibly involved in its pathophysiology. Beyond neuronal commitment, many groups have proposed the involvement of glial activity in psychiatric disorders. Other biochemical markers, particularly associated with oxidative stress, have been studied in BD. In the present study, we evaluated glial involvement and oxidative stress in patients with BD. Glial activity was assessed by measuring serum S100B content; oxidative stress was assessed using serum thiobarbituric acid reactive substances (TBARS) and activities of antioxidant enzymes in BD patients during different episodes of disease. We found a significant increment of serum S100B during episodes of mania and depression, but not in euthymic patients. Superoxide dismutase (SOD) activity, as well the SOD/glutathione peroxidase plus catalase ratio, was also increased in manic and depressed patients. On the other hand, TBARS levels were increased in BD patients regardless of the phase of the disorder. These findings suggest a potential oxidative damage in BD patients. This peripheral oxidative imbalance indicates that systemic changes are taking place during the active phases of the illness. Such changes appear to relate to astrocyte function, as indicated by serum S100B elevation.

DNA damage in rats after treatment with methylphenidate

BACKGROUND

Methylphenidate (MPH) is a widely prescribed psychostimulant for the treatment of attention-deficit hyperactivity disorder (ADHD). Recently, some studies have addressed the genotoxic potential of the MPH, but the results have been contradictory. Hence, the present study aimed to investigate the index of cerebral and peripheral DNA damage in young and adult rats after acute and chronic MPH exposure.

METHODS

We used (1) single cell gel electrophoresis (Comet assay) to measure early DNA damage in hippocampus, striatum and total blood, and (2) micronucleus test in total blood samples.

RESULTS

Our results showed that MPH increased the peripheral index of early DNA damage in young and adult rats, which was more pronounced with chronic treatment and in the striatum compared to the hippocampus. Neither acute nor chronic MPH treatment increased micronucleus frequency in young or in adult rats. Peripheral DNA damage was positively correlated with striatal DNA damage.

CONCLUSION

These results suggest that MPH may induce central and peripheral early DNA damage, but this early damage may be repaired.

A gastrin-releasing peptide receptor antagonist blocks D-amphetamine-induced hyperlocomotion and increases hippocampal NGF and BDNF levels in rats

The gastrin-releasing peptide receptor (GRPR) has emerged as a novel molecular target in neurological and psychiatric disorders, and previous animal studies suggest that GRPR antagonists might display cognitive-enhancing and antipsychotic properties. Hyperlocomotion produced by administration of D-amphetamine (D-AMPH) to rats has been put forward as a model of the manic phase of bipolar disorder (BD). In the present study, we examined the effects of a single systemic administration of the GRPR antagonist [D-Tpi(6), Leu(13) psi(CH(2)NH)-Leu(14)] bombesin (6-14) (RC-3095) on hyperlocomotion induced by a single systemic injection of D-AMPH in male rats. We also evaluated the levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampus of rats treated with D-AMPH and RC-3095. Administration of RC-3095 at any of the doses used blocked D-AMPH-induced hyperlocomotion. Specific doses of RC-3095 increased the levels of NGF and BDNF in the dorsal hippocampus. Administration of D-AMPH did not affect NGF or BDNF levels by itself, but blocked the RC-3095 effects. The results suggest that GRPR antagonists might display anti-manic activity.

Traumatic life events in bipolar disorder: impact on BDNF levels and psychopathology

BACKGROUND

There is evidence that vulnerability to depression and anxiety disorders is markedly increased by traumatic life events. While childhood abuse has been reported to be associated with poorer outcomes in bipolar disorder, little is known about the neurobiological basis underlying this association. The aim of this study was to ascertain whether bipolar patients who were exposed to a traumatic event or events (TE) have lower brain-derived neurotrophic factor (BDNF) levels and more severe psychopathology as indicated by increased comorbidity and other clinical features when compared to those who were not exposed to TE.

METHODS

One-hundred and sixty-three consecutively recruited bipolar outpatients were assessed by Structured Clinical Interview for DSM-IV (SCID) and standard protocol in order to evaluation psychopathology and clinical features. The reported TE was assessed using DSM-IV stem criteria for trauma (as defined by A1 and A2 criteria for trauma for post-traumatic stress disorder). Subjects were divided into 2 groups according to presence or absence of lifetime TE. The levels of BDNF, comorbidity and other clinical features were compared between groups.

RESULTS

After adjusting for confounders, results indicated that bipolar patients with a history of TE have alcohol abuse/dependence (p < 0.001), anxiety comorbidity, and lower levels of serum BDNF (p < 0.01) compared to those without a history of TE. There was no difference between the 2 groups in age of onset, presence of psychosis, other substance abuse and dependence, rapid cycling or suicide attempts.

CONCLUSIONS

Our findings suggest that TE are associated with significantly increased prevalence of alcohol and anxiety comorbidity as well as lower BDNF levels in bipolar patients. It is possible that a decrease in BDNF levels may account for increased comorbidity, but further prospective studies are required to confirm this.

Oxidative stress parameters in unmedicated and treated bipolar subjects during initial manic episode: A possible role for lithium antioxidant effects

Studies have proposed the involvement of oxidative stress and neuronal energy dysfunctions in the pathophysiology of bipolar disorder (BD). This study evaluates plasma levels of the oxidative/energy metabolism markers, thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and neuron-specific enolase (NSE) during initial episodes of mania compared to controls in 75 subjects. Two groups of manic subjects (unmedicated n=30, and lithium-treated n=15) were age/gender matched with healthy controls (n=30). TBARS and antioxidant enzymes activity (SOD and CAT) were increased in unmedicated manic patients compared to controls. Conversely, plasma NSE levels were lower during mania than in the controls. In contrast, acute treatment with lithium showed a significant reduction in both SOD/CAT ratio and TBARS levels. These results suggest that initial manic episodes are associated with both increased oxidative stress parameters and activated antioxidant defenses, which may be related to dysfunctions on energy metabolism and neuroplasticity pathways. Antioxidant effects using lithium in mania were shown, and further studies are necessary to evaluate the potential role of these effects in the pathophysiology and therapeutics of BD.