Camila Guindalini

Nuclear Receptor Rev-Erb-α Circadian Gene Variants and Lithium Carbonate Prophylaxis in Bipolar Affective Disorder

Rev-erb-α is one of the key components of the mammalian circadian mechanism; recently, it was also reported to be involved in the biological action of lithium. We investigated whether polymorphisms in the Rev-erb- α gene are associated with the long-term efficacy of lithium carbonate therapy in bipolar affective disorder. Seven single nucleotide polymorphisms (SNPs) were genotyped in a well-characterized sample of patients from Sardinia, Italy, who were followed prospectively for up to 27 years. Genotypic and allelic analysis did not show evidence for association between the polymorphisms and the different levels of lithium response. Further analyses grouping the different levels of response demonstrated that when the patients were separated into groups of nonresponders versus individuals who have had at least a minor or modest improvement in frequency of episodes or admissions, there was a significant increase in the frequency of the T allele in the nonresponder group (p = 0.0008). Logistic regression analyses showed that patients carrying at least one copy of the T allele for the rs2314339 marker were shown to be approximately 3.5 times more likely to have no improvement or even a worsening of the illness (odds ratio [OR], 3.56; 95% confidence interval [CI], 1.18-10.76). The results of this study may help to identify potential biological markers that can serve to predict the response of bipolar affective disorder patients to treatment, improving treatment efficacy.

Violence and post-traumatic stress disorder in Sao Paulo and Rio de Janeiro, Brazil: the protocol for an epidemiological and genetic survey

Backgroundviolence is a public health major concern, and it is associated with post-traumatic stress disorder and other psychiatric outcomes. Brazil is one of the most violent countries in the world, and has an extreme social inequality. Research on the association between violence and mental health may support public health policy and thus reduce the burden of disease attributable to violence. The main objectives of this project were: to study the association between violence and mental disorders in the Brazilian population; to estimate the prevalence rates of exposure to violence, post-traumatic stress disorder, common metal disorder, and alcohol hazardous use and dependence: and to identify contextual and individual factors, including genetic factors, associated with the outcomes.Methods/designone phase cross-sectional survey carried out in Sao Paulo and Rio de Janeiro, Brazil. A multistage probability to size sampling scheme was performed in order to select the participants (3000 and 1500 respectively). The cities were stratified according to homicide rates, and in Sao Paulo the three most violent strata were oversampled. The measurements included exposure to traumatic events, psychiatric diagnoses (CIDI 2.1), contextual (homicide rates and social indicators), and individual factors, such as demographics, social capital, resilience, help seeking behaviours. The interviews were carried between June/2007 February/2008, by a team of lay interviewers. The statistical analyses will be weight-adjusted in order to take account of the design effects. Standardization will be used in order to compare the results between the two centres. Whole genome association analysis will be performed on the 1 million SNP (single nucleotide polymorphism) arrays, and additional association analysis will be performed on additional phenotypes. The Ethical Committee of the Federal University of Sao Paulo approved the study, and participants who matched diagnostic criteria have been offered a referral to outpatient clinics at the Federal University of Sao Paulo and Federal University of Rio de Janeiro.

Loss of the Ca2+/calmodulin-dependent protein kinase type IV in dopaminoceptive neurons enhances behavioral effects of cocaine

The persistent nature of addiction has been associated with activity-induced plasticity of neurons within the striatum and nucleus accumbens (NAc). To identify the molecular processes leading to these adaptations, we performed Cre/loxP-mediated genetic ablations of two key regulators of gene expression in response to activity, the Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) and its postulated main target, the cAMP-responsive element binding protein (CREB). We found that acute cocaine-induced gene expression in the striatum was largely unaffected by the loss of CaMKIV. On the behavioral level, mice lacking CaMKIV in dopaminoceptive neurons displayed increased sensitivity to cocaine as evidenced by augmented expression of locomotor sensitization and enhanced conditioned place preference and reinstatement after extinction. However, the loss of CREB in the forebrain had no effect on either of these behaviors, even though it robustly blunted acute cocaine-induced transcription. To test the relevance of these observations for addiction in humans, we performed an association study of CAMK4 and CREB promoter polymorphisms with cocaine addiction in a large sample of addicts. We found that a single nucleotide polymorphism in the CAMK4 promoter was significantly associated with cocaine addiction, whereas variations in the CREB promoter regions did not correlate with drug abuse. These findings reveal a critical role for CaMKIV in the development and persistence of cocaine-induced behaviors, through mechanisms dissociated from acute effects on gene expression and CREB-dependent transcription.

Prevalence and correlates for sleep complaints in older adults in low and middle income countries: a 10/66 Dementia Research Group study.

BACKGROUND Although it is well recognized that the prevalence of sleep complaints increases with age, estimates in developing countries are still unknown. The present study aims to estimate the prevalence and prevalence ratios of the correlates of sleep complaints in a large population of older adults from low and middle income countries (LAMICs). METHODS A cross-sectional survey was performed in 16,680 65 year-old or older residents in catchment areas of Cuba, the Dominican Republic, Peru, Venezuela, Mexico, China, India, and Puerto Rico (10/66 Dementia Research Group study). Information about socio-demographic factors, lifestyle, health, and sleep complaints was obtained. Results were standardized by age, sex, household clustering, and residence site (urban or rural). Prevalence ratios were derived for each country and fixed effects meta-analyses were used to combine them. RESULTS The standardized prevalence of sleep complaints varied from 9.1% (China) to 37.7% (India). The meta-analysis showed that female gender, urban residence, low educational level, low physical activity status, high pain scores, poor health, higher memory impairment score, presence of major depression, mild cognitive impairment, and high number of co-morbidities were associated with sleep complaints. CONCLUSIONS This study robustly characterized the prevalence of sleep complaints in large samples of the elderly in LAMICs and identified potential risk factors that may be specific to these populations. This approach can help to direct health-care efforts related to sleep disturbances in these countries.

Adenosine Deaminase Polymorphism Affects Sleep EEG Spectral Power in a Large Epidemiological Sample

Slow wave oscillations in the electroencephalogram (EEG) during sleep may reflect both sleep need and intensity, which are implied in homeostatic regulation. Adenosine is strongly implicated in sleep homeostasis, and a single nucleotide polymorphism in the adenosine deaminase gene (ADA G22A) has been associated with deeper and more efficient sleep. The present study verified the association between the ADA G22A polymorphism and changes in sleep EEG spectral power (from C3-A2, C4-A1, O1-A2, and O2-A1 derivations) in the Epidemiologic Sleep Study (EPISONO) sample from São Paulo, Brazil. Eight-hundred individuals were subjected to full-night polysomnography and ADA G22A genotyping. Spectral analysis of the EEG was carried out in all individuals using fast Fourier transformation of the signals from each EEG electrode. The genotype groups were compared in the whole sample and in a subsample of 120 individuals matched according to ADA genotype for age, gender, body mass index, caffeine intake status, presence of sleep disturbance, and sleep-disturbing medication. When compared with homozygous GG genotype carriers, A allele carriers showed higher delta spectral power in Stage 1 and Stages 3+4 of sleep, and increased theta spectral power in Stages 1, 2 and REM sleep. These changes were seen both in the whole sample and in the matched subset. The higher EEG spectral power indicates that the sleep of individuals carrying the A allele may be more intense. Therefore, this polymorphism may be an important source of variation in sleep homeostasis in humans, through modulation of specific components of the sleep EEG.

To what extent is sleep rebound effective in reversing the effects of paradoxical sleep deprivation on gene expression in the brain

Sleep is essential to maintaining health and well-being. It has been demonstrated that some of the biological alterations caused by paradoxical sleep deprivation (PSD) are not completely reversed after a period of sleep rebound (SR). The purpose of this study was to determine to what extent the specific molecular changes that occur in the rat cerebral cortex after 96 h of PSD can effectively be reversed during 24h of recovery. Total RNA from the right cerebral cortex of Wistar male rats and GeneChip Rat Genome 230 2.0 arrays were used to perform comprehensive microarray analysis of gene expression in control, PSD and SR groups. Microarray data were validated by Real Time qPCR. A total of 78 unique transcripts were differently expressed after PSD relative to control levels. These include genes related to metabolic processes, the circadian sleep-wake cycle, response to stimuli, regulation of cell proliferation and signaling pathways. After 24h of sleep rebound, approximately 62% of the sleep deprivation transcripts were again detected as differently expressed in the SR relative to the PSD group, although in the opposite direction. On the other hand, the expression of the remaining transcripts showed intermediate values between control and sleep-deprived animals. In summary, our results provide a unique set of transcripts that might be specific related to regulation of paradoxical sleep phase and sleep homeostasis processes, as well as to the biological basis of sleep disorders.

A review of psychiatric genetics research in the Brazilian population

OBJECTIVE AND METHOD A large increase in the number of Brazilian studies on psychiatric genetics has been observed in the 1970s since the first publications conducted by a group of researchers in Brazil. Here we reviewed the literature and evaluated the advantages and difficulties of psychiatric genetic studies in the Brazilian population. CONCLUSION The Brazilian population is one of the most heterogeneous populations in the world, formed mainly by the admixture between European, African and Native American populations. Although the admixture process is not a particularity of the Brazilian population, much of the history and social development in Brazil underlies the ethnic melting pot we observe nowadays. Such ethnical heterogeneity of the Brazilian population obviously brings some problems when performing genetic studies. However, the Brazilian population offers a number of particular characteristics that are of major interest when genetic studies are carried out, such as the presence of isolated populations. Thus, differences in the genetic profile and in the exposure to environmental risks may result in different interactions and pathways to psychopathology.

The Posttraumatic Stress Disorder Project in Brazil: Neuropsychological, Structural and Molecular Neuroimaging Studies in Victims of Urban Violence

BackgroundLife trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies.Methods and designCases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases) will be compared to resilient victims of traumatic life experiences without PTSD (controls) aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured Clinical Interview for DSM-IV and the Clinician-Administered PTSD Scale, Beck Anxiety Inventory, Beck Depression Inventory, Global Assessment of Function, The Social Adjustment Scale, Medical Outcomes Study 36-Item Short-Form Health Survey, Early Trauma Inventory, Clinical global Impressions, and Peritraumatic Dissociative Experiences Questionnaire). A broad neuropsychological battery will be administered for all participants of the neuropsychological study. Magnetic resonance scans will be performed to acquire structural neuroimaging data. Single photon emission computerized tomography with [(99m)Tc]-TRODAT-1 brain scans will be performed to evaluate dopamine transporters.DiscussionThis study protocol will be informative for researchers and clinicians interested in considering, designing and/or conducting translational research in the field of trauma and posttraumatic stress disorder.

Association Between Uric Acid Levels and Obstructive Sleep Apnea Syndrome in a Large Epidemiological Sample

Introduction Recurrent hypoxia, which is associated with obstructive sleep apnea syndrome (OSAS), leads to an increase in the degradation of adenosine triphosphatase into xanthine, which in turn increases uric acid concentrations. Objective The current study aimed to determine whether an association exists between OSAS and uric acid levels in the peripheral blood from a representative population of Sao Paulo (Brazil). Methods A population-based survey adopting a probabilistic 3-stage cluster sample of Sao Paulo was used to represent the population according to gender, age, and socioeconomic class. A total of 1,042 volunteers underwent polysomnography recordings for OSAS diagnosis, blood pressure assessment, and biochemical blood analysis, and answered questionnaires. Results Uric acid levels were correlated with most important risk factors for OSAS, such as AHI, desaturation time and index, minimum oxyhemoglobin saturation (SpO2), blood pressure, cholesterol, BMI, triglycerides and arousal, and with OSAS itself. Also, uric acid was increased in OSAS volunteers even after controlling for all confounders. Hyperuricemic volunteers presented lower mean and minimum SpO2 and increased desaturation index. Importantly, minimum SpO2 was a significant predictor of uric acid levels, which in turn was considered an independent predictor for OSAS in the binary logistic model. However, a ROC curve analysis for establishing cut-off points for uric acid levels as a biomarker of OSAS revealed moderate sensitivity and specificity. Conclusion A strong association was found between uric acid levels and OSAS in a representative sample of the population of Sao Paulo. Although they do not qualify for a biomarker alone, uric acid levels may be involved in OSAS severity and should be considered in sleep apnea management in the future.

Validation of commonly used reference genes for sleep-related gene expression studies

BackgroundSleep is a restorative process and is essential for maintenance of mental and physical health. In an attempt to understand the complexity of sleep, multidisciplinary strategies, including genetic approaches, have been applied to sleep research. Although quantitative real time PCR has been used in previous sleep-related gene expression studies, proper validation of reference genes is currently lacking. Thus, we examined the effect of total or paradoxical sleep deprivation (TSD or PSD) on the expression stability of the following frequently used reference genes in brain and blood: beta-actin (b-actin), beta-2-microglobulin (B2M), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and hypoxanthine guanine phosphoribosyl transferase (HPRT).ResultsNeither TSD nor PSD affected the expression stability of all tested genes in both tissues indicating that b-actin, B2M, GAPDH and HPRT are appropriate reference genes for the sleep-related gene expression studies. In order to further verify these results, the relative expression of brain derived neurotrophic factor (BDNF) and glycerol-3-phosphate dehydrogenase1 (GPD1) was evaluated in brain and blood, respectively. The normalization with each of four reference genes produced similar pattern of expression in control and sleep deprived rats, but subtle differences in the magnitude of expression fold change were observed which might affect the statistical significance.ConclusionThis study demonstrated that sleep deprivation does not alter the expression stability of commonly used reference genes in brain and blood. Nonetheless, the use of multiple reference genes in quantitative RT-PCR is required for the accurate results.