RODRIGO MACHADO VIEIRA
Projetos de Pesquisa
Unidades Organizacionais
LIM/27 - Laboratório de Neurociências, Hospital das Clínicas, Faculdade de Medicina
14 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 14
- Regulation of leukocyte tricarboxylic acid cycle in drug-naive Bipolar Disorder(2015) SOUSA, Rafael T. de; STRECK, Emilio L.; FORLENZA, Orestes V.; BRUNONI, Andre R.; ZANETTI, Marcus V.; FERREIRA, Gabriela K.; DINIZ, Breno S.; PORTELA, Luis V.; CARVALHO, Andre F.; ZARATE JR., Carlos A.; GATTAZ, Wagner F.; MACHADO-VIEIRA, RodrigoSeveral lines of evidence suggest a role for mitochondrial dysfunction in the pathophysiology of bipolar disorder (BD). The tricarboxylic acid cycle (TCA cycle) is fundamental for mitochondrial energy production and produces substrates used in oxidative phosphorylation by the mitochondrial electron transport chain. The activity of the key TCA cycle enzymes citrate synthase, malate dehydrogenase, and succinate dehydrogenase has never been evaluated in BD. In the present study, these enzymes were assayed from leukocytes of drug-naive BD patients in a major depressive episode (n = 18) and compared to 24 age-matched healthy controls. Drug-naive BD patients did not show differences in activities of citrate synthase (p = 0.79), malate dehydrogenase (p = 0.17), and succinate dehydrogenase (p = 0.35) compared with healthy controls. No correlation between any TCA cycle enzyme activity and severity of depressive symptoms was observed. Overall, these data suggest that the activities of the TCA cycle enzymes are not altered in major depressive episodes of recent-onset BD, which may support the concept of illness staging and neuroprogression in BD.
- Lithium and neuroprotection: translational evidence and implications for the treatment of neuropsychiatric disorders(2013) DINIZ, Breno Satler; MACHADO-VIEIRA, Rodrigo; FORLENZA, Orestes VicenteIn the last two decades, a growing body of evidence has shown that lithium has several neuroprotective effects. Several neurobiological mechanisms have been proposed to underlie these clinical effects. Evidence from preclinical studies suggests that neuroprotection induced by lithium is mainly related to its potent inhibition of the enzyme glycogen synthase kinase-3 beta (GSK-3 beta) and its downstream effects, ie, reduction of both tau protein phosphorylation and amyloid-beta(42) production. Additional neuroprotective effects include increased neurotrophic support, reduced proinflammatory status, and decreased oxidative stress. More recently, neuroimaging studies in humans have demonstrated that chronic use is associated with cortical thickening, higher volume of the hippocampus and amygdala, and neuronal viability in bipolar patients on lithium treatment. In line with this evidence, observational and case registry studies have shown that chronic lithium intake is associated with a reduced risk of Alzheimer's disease in subjects with bipolar disorder. Evidence from recent clinical trials in patients with mild cognitive impairment suggests that chronic lithium treatment at subtherapeutic doses can reduce cerebral spinal fluid phosphorylated tau protein. Overall, convergent lines of evidence point to the potential of lithium as an agent with disease modifying properties in Alzheimer's disease. However, additional long-term studies are necessary to confirm its efficacy and safety for these patients, particularly as chronic intake is necessary to achieve the best therapeutic results.
- Does Lithium Prevent Alzheimer's Disease?(2012) FORLENZA, Orestes V.; PAULA, Vanessa J. de; MACHADO-VIEIRA, Rodrigo; DINIZ, Breno S.; GATTAZ, Wagner F.Lithium salts have a well-established role in the treatment of major affective disorders. More recently, experimental and clinical studies have provided evidence that lithium may also exert neuroprotective effects. In animal and cell culture models, lithium has been shown to increase neuronal viability through a combination of mechanisms that includes the inhibition of apoptosis, regulation of autophagy, increased mitochondrial function, and synthesis of neurotrophic factors. In humans, lithium treatment has been associated with humoral and structural evidence of neuroprotection, such as increased expression of anti-apoptotic genes, inhibition of cellular oxidative stress, synthesis of brain-derived neurotrophic factor (BDNF), cortical thickening, increased grey matter density, and hippocampal enlargement. Recent studies addressing the inhibition of glycogen synthase kinase-3 beta (GSK3B) by lithium have further suggested the modification of biological cascades that pertain to the pathophysiology of Alzheimer's disease (AD). A recent placebo-controlled clinical trial in patients with amnestic mild cognitive impairment (MCI) showed that long-term lithium treatment may actually slow the progression of cognitive and functional deficits, and also attenuate Tau hyperphosphorylation in the MCI-AD continuum. Therefore, lithium treatment may yield disease-modifying effects in AD, both by the specific modification of its pathophysiology via inhibition of overactive GSK3B, and by the unspecific provision of neurotrophic and neuroprotective support. Although the clinical evidence available so far is promising, further experimentation and replication of the evidence in large scale clinical trials is still required to assess the benefit of lithium in the treatment or prevention of cognitive decline in the elderly.
- Lithium increases plasma brain-derived neurotrophic factor in acute bipolar mania: A preliminary 4-week study(2011) SOUSA, Rafael T. de; BILT, Martinus T. van de; DINIZ, Breno S.; LADEIRA, Rodolfo B.; PORTELA, Luis V.; SOUZA, Diogo O.; FORLENZA, Orestes V.; GATTAZ, Wagner F.; MACHADO-VIEIRA, RodrigoSeveral studies have suggested an important role for brain-derived neurotrophic factor (BDNF) in the pathophysiology and therapeutics of bipolar disorder (BPD). The mechanisms underlying the therapeutic effects of lithium in BPD seem to involve a direct regulation of neurotrophic cascades. However, no clinical study evaluated the specific effects of lithium on BDNF levels in subjects with BPD. This study aims to investigate the effects of lithium monotherapy on BDNF levels in acute mania. Ten subjects with bipolar I disorder in a manic episode were evaluated at baseline and after 28 days of lithium therapy. Changes in plasma BDNF levels and Young Mania Rating Scale (YMRS) scores were analyzed. A significant increase in plasma BDNF levels was observed after 28 days of therapy with lithium monotherapy (510.9 +/- 127.1 pg/mL) compared to pre-treatment (406.3 +/- 69.5 pg/mL) (p = 0.03). Although it was not found a significant association between BDNF levels and clinical improvement (YMRS), 87% of responders presented an increase in BDNF levels after treatment with lithium. These preliminary data showed lithium's direct effects on BDNF levels in bipolar mania, suggesting that short-term lithium treatment may activate neurotrophic cascades. Further studies with larger samples and longer period may confirm whether this biological effect is involved in the therapeutic efficacy of lithium in BPD.
- Cognitive impairment in late-life bipolar disorder is not associated with Alzheimer's disease pathological signature in the cerebrospinal fluid(2016) FORLENZA, Orestes V.; APRAHAMIAN, Ivan; RADANOVIC, Marcia; TALIB, Leda L.; CAMARGO, Marina Z. A.; STELLA, Florindo; MACHADO-VIEIRA, Rodrigo; GATTAZ, Wagner F.ObjectivesCognitive impairment is a common feature of late-life bipolar disorder (BD). Yet, there is limited information on the biological mechanisms associated with this process. It is uncertain whether cognitively impaired patients with BD may present the Alzheimer's disease (AD) bio-signature in the cerebrospinal fluid (CSF), defined as a combination of low concentrations of the amyloid-beta peptide (A(1-42)) and high concentrations of total tau (T-tau) and tau phosphorylated at threonine 181 (P-tau). In this study, we sought to determine whether cognitive impairment in elderly patients with BD is associated with the AD CSF bio-signature. MethodsSeventy-two participants were enrolled in the study. The test group comprised older adults with BD and mild cognitive impairment (BD-MCI; n=16) and the comparison groups comprised patients with dementia due to AD (n=17), patients with amnestic MCI (aMCI; n=14), and cognitively healthy older adults (control group; n=25). CSF samples were obtained by lumbar puncture and concentrations of A(1-42), T-tau and P-tau were determined. ResultsCSF concentrations of all biomarkers were significantly different in the AD group compared to all other groups, but did not differentiate BD-MCI subjects from aMCI subjects and controls. BD-MCI patients had a non-significant reduction in CSF A(1-42) compared to controls, but this was still higher than in the AD group. Concentrations of T-tau and P-tau in BD-MCI patients were similar to those in controls, and significantly lower than those in AD. ConclusionsCognitively impaired patients with BD do not display the so-called AD bio-signature in the CSF. We therefore hypothesize that cognitive deterioration in BD is not associated with the classical pathophysiological mechanisms observed in AD, i.e., amyloid deposition and hyperphosphorylation of microtubule-associated tau protein.
- Early improvement of psychotic symptoms with lithium monotherapy as a predictor of later response in mania(2012) SOUSA, Rafael T. de; BUSNELLO, Joao V.; FORLENZA, Orestes V.; ZANETTI, Marcus V.; SOEIRO-DE-SOUZA, Marcio G.; BILT, Martinus T. van de; MORENO, Ricardo A.; ZARATE JR., Carlos A.; GATTAZ, Wagner F.; MACHADO-VIEIRA, RodrigoAlthough lithium has been the first line agent in the treatment of bipolar disorder (BD), few studies have evaluated lithium's efficacy in mania with psychosis and its association with later response. Furthermore, given the widespread concern about antipsychotic side effects, answering a question about whether lithium alone can manage to treat both psychotic and non-psychotic mania seems a very relevant one. The present study addresses the antipsychotic efficacy of lithium monotherapy in acute mania and early improvement of psychotic symptoms as a predictor of later response of manic symptoms. Forty-six patients presenting a manic episode (32 with psychotic features and 14 subjects without psychotic features) were treated for 4 weeks with lithium monotherapy and evaluated weekly using the Young Mania Rating Scale (YMRS). Subjects with rapid cycling, substance abuse/dependence, or mixed episodes were excluded. The overall antimanic efficacy of lithium in psychosis vs. non-psychosis groups was evaluated. In addition, early improvement of psychotic symptoms and its prediction of subsequent response (>50% decrease in total YMRS scores) or remission were evaluated. Lithium showed a similar efficacy in both psychosis and non-psychosis mania. Early improvement of psychotic symptoms was associated with clinical response and remission at endpoint.
- Reduced Cerebrospinal Fluid Levels of Brain-Derived Neurotrophic Factor Is Associated With Cognitive Impairment in Late-Life Major Depression(2014) DINIZ, Breno S.; TEIXEIRA, Antonio L.; MACHADO-VIEIRA, Rodrigo; TALIB, Leda L.; RADANOVIC, Marcia; GATTAZ, Wagner F.; FORLENZA, Orestes V.Objectives. Late-life depression (LLD) is associated with reduced neurotrophic support and abnormalities in neurodegenerative cascades. The aim of the present study is to determine the concentrations of brain-derived neurotrophic factor (BDNF), amyloid-beta(42), total Tau, and phosphorylated Tau in the cerebrospinal fluid (CSF) of patients with LLD and cognitive impairment compared to healthy older adults. Method. We included 25 antidepressant-free patients with LLD (10 with mild cognitive impairment [LLD + MCI] and 15 with no cognitive decline [LLD + NCD]) and 25 healthy older adults as a comparison group. Depressive symptoms were assessed by the 21-item Hamilton Depression Rating Scale (HDRS-21) and cognitive performance by a comprehensive cognitive battery. Results. Patients with LLD + MCI showed significantly lower CSF BDNF levels compared to LLD + NCD and healthy controls (p = .003). There were no significant differences in Alzheimer's disease-related CSF biomarkers between groups. CSF BDNF concentrations were positively correlated with Cambridge Cognitive Test (CAMCOG) scores (r = .36, p = .02). Discussion. The present study adds to the growing body of evidence that abnormalities in the BDNF system are involved in the pathophysiology of LLD. The reduction of the availability of BDNF in the central nervous system may indicate increased vulnerability to the development of several age-related neuropsychiatric disorders as well as to adverse cognitive outcomes.
- Current pharmacological approaches and perspectives in the treatment of geriatric mood disorders(2011) DINIZ, Breno S.; NUNES, Paula V.; MACHADO-VIEIRA, Rodrigo; FORLENZA, Orestes V.Purpose of review This work aims to review the most recent developments in the treatment of mood disorders (major depression and bipolar disorder) in the elderly. Recent findings In the last years, few new pharmacological interventions for mood disorders have been developed. Recent studies seek to provide alternative treatment strategies to achieve higher remission rates, including the association of antidepressants, mood stabilizers and psychotherapy and the treatment of specific clusters of symptoms, such as the adjunctive treatment of cognitive impairment with cholinesterase inhibitors. Also, recent studies have been assessing the potential of pharmacogenetic information in the prediction of treatment outcomes. Summary These factors altogether are expected to help the development of personalized treatment strategies that may improve outcomes with fewer adverse effects.
- A Selective Association between Central and Peripheral Lithium Levels in Remitters in Bipolar Depression: A 3T-Li-7 Magnetic Resonance Spectroscopy Study(2016) MACHADO-VIEIRA, R.; OTADUY, M. C.; ZANETTI, M. V.; SOUSA, R. T. De; DIAS, V. V.; LEITE, C. C.; FORLENZA, O. V.; BUSATTO, G. F.; SOARES, J. C.; GATTAZ, W. F.ObjectiveThe objective of this study was to evaluate brain lithium levels using Li-7 magnetic resonance spectroscopy after 6 weeks of lithium therapy in bipolar depression to test the hypothesis that brain and plasma lithium are correlated. It was also tested whether responders and remitters have different pharmacokinetics, blood and brain lithium levels (ratio) compared with those presenting suboptimal antidepressant improvement. MethodTwenty-three patients with bipolar disorder (I and II) during depressive episodes were included and followed up for 6 weeks at the University of Sao Paulo using flexible dose of lithium (450-900 mg/day). Sixteen patients were drug-naive. At endpoint, patients underwent a Li-7-MRS scan and brain lithium concentrations were calculated. ResultsA significant association between central and peripheral lithium levels was found only in remitters (r = 0.7, P = 0.004) but not in non-remitters (r = -0.12, P = 0.76). Also, brain lithium (but not plasma) was inversely correlated with age (r = -0.46, P = 0.025). Plasma lithium did not correlate with any clinical outcome, lithium dosage or adverse effects. ConclusionThese findings suggest that non-remitters may not transport lithium properly to the brain, which may underlie treatment resistance to lithium in BD. Future studies with Li-7-MRS integrated with the evaluation of blood-brain barrier transport mechanisms and longitudinal clinical outcomes in BD and aging are warranted.
- Lithium safety and tolerability in mood disorders: a critical review(2014) APRAHAMIAN, Ivan; SOUSA, Rafael Teixeira de; VALIENGO, Leandro da Costa Lane; MACHADO-VIEIRA, Rodrigo; FORLENZA, Orestes VicenteBackground : Lithium is a first-line treatment for bipolar disorder in all phases, also indicated as add-on drug for unipolar depression and suicide prevention. This study encompasses a broad critical review on the safety and tolerability of lithium for mood disorders. Methods : A computerized search for English written human studies was made in MEDLINE, using the keywords “lithium” and “mood disorders”, starting from July 1993 through July 2013 (n = 416). This initial search aimed to select clinical trials, prospective data, and controlled design studies of lithium treatment for mood disorders reporting adverse effects (n = 36). The final selection yielded 91 studies. Results : The most common general side effects in patients on lithium treatment were thirst, frequent urination, dry mouth, weight gain, fatigue and cognitive complaints. Lithium users showed a high prevalence of hypothyroidism, hyperparathyroidism, and decrease in urinary concentration ability. Reduction of glomerular filtration rate in patients using lithium was also observed, but in a lesser extent. The evidence of teratogenicity associated with lithium use is not well established. Anti-inflammatory non-steroidal drugs, thiazide diuretics, angiotensin-converting enzyme inhibitors, and alprazolam may increase serum lithium and the consequent risk for intoxication. Discussion : Short-term lithium treatment is associated with mild side effects. Medium and long-term lithium treatment, however, might have effects on target organs which may be prevented by periodical monitoring. Overall, lithium is still a safe option for the treatment of mood disorders.