Percorrer por autor "Canedo, Teresa"
A mostrar 1 - 10 de 15
Resultados por página
Opções de ordenação
- Astrocyte-derived TNF and glutamate critically modulate microglia activation by methamphetaminePublication . Canedo, Teresa; Portugal, Camila Cabral; Socodato, Renato; Almeida, Tiago Oliveira; Terceiro, Ana Filipa; Bravo, Joana; Silva, Ana Isabel; Magalhães, João Duarte; Guerra-Gomes, Sónia; Oliveira, João Filipe; Sousa, Nuno; Magalhães, Ana; Relvas, João Bettencourt; Summavielle, TeresaMethamphetamine (Meth) is a powerful illicit psychostimulant, widely used for recreational purposes. Besides disrupting the monoaminergic system and promoting oxidative brain damage, Meth also causes neuroinflammation, contributing to synaptic dysfunction and behavioral deficits. Aberrant activation of microglia, the largest myeloid cell population in the brain, is a common feature in neurological disorders triggered by neuroinflammation. In this study, we investigated the mechanisms underlying the aberrant activation of microglia elicited by Meth in the adult mouse brain. We found that binge Meth exposure caused microgliosis and disrupted risk assessment behavior (a feature that usually occurs in individuals who abuse Meth), both of which required astrocyte-to-microglia crosstalk. Mechanistically, Meth triggered a detrimental increase of glutamate exocytosis from astrocytes (in a process dependent on TNF production and calcium mobilization), promoting microglial expansion and reactivity. Ablating TNF production, or suppressing astrocytic calcium mobilization, prevented Meth-elicited microglia reactivity and re-established risk assessment behavior as tested by elevated plus maze (EPM). Overall, our data indicate that glial crosstalk is critical to relay alterations caused by acute Meth exposure.
- Blockingmethamphetamine-induced microglia reactivity by targeting glutamate receptorsPublication . Summavielle, Teresa; Canedo, Teresa; Silva, Ana Isabel; Andrade, Elva Bonifácio; Almeida, Tiago O.; Bravo, Joana; Terceiro, Ana Filipa; Canedo, Teresa; Silva, Ana Isabel; Magalhães, Ana; Relvas, João B.; Bonifácio Andrade, Elva; Bravo, JoanaExposure to psychostimulants has been classically associated with damage to neuronal terminals. However, it is now accepted that interaction between neuronal and glial cells also contributes to the addictive behavior. We have recently shown that acute methamphetamine (Meth), a powerful psychostimulant, causes microgliosis and increases microglia activation through astrocytic-TNF release1. We are now interested in clarifying the progression of neuroinflammation under chronic drug exposure and how different brain and immune cells contribute to this inflammatory process.To explore this, firstly, we performed a proteomic analysis, in different phases of the addictive process, in mice exposed to an escalating dosing of Meth for ten days (Meth10d). To validate the conditioning power of our model, mice were tested in a condition place preference (CPP) at 10d of Meth, and 2 or 10 days of withdrawal (WD). At all these time points, mice were seen to be strongly conditioned by Meth. Next, we conducted a proteomic analysis to compare the different time points (using the hippocampus, where we previously found robust microgliosis underMeth1). We found a proteome profile that varied substantially with exposure (Meth10d) and after a short- (WD2d)and long-term withdrawal (WD10d) periods. Interestingly, the most altered pathways were neuro transmitter-related.However, we also identified significant differences in Wnt signaling, which was previously linked to regulation of microglia reactivity. As such, we evaluated the microglia profile after chronic Meth exposure and at withdrawal. In the hippocampus, the number of microglia cells was significantly increased at Meth10d and remained also increased at WD2d. Microglia presented a more ameboid-like shape at Meth10d, but its ramified morphology was recovered at WD2d. Importantly, our proteomic data also revealed that during Meth withdrawal, several microglial receptors were down regulated, suggesting that microglia was in a “primed” state. In addition, as the crosstalk between neurons and microglia seems to be relevant for the behavioral expression of Meth, we are dissecting the modulation of microgliaby neurons under Meth exposure, to evaluate neuroimmune regulatory ligand-receptor pairs that seem to impact on the neuron-microglia interaction. Of note, some these ligand-receptor pairs seem to be down regulated by chronic Meth and during abstinence, which may be associated with reduced neuronal ability to down regulate microglia reactivity, and lead to increased neuronal damage. We fore see that these receptors may prove to be interesting therapeutic targets for the treatment of addiction, and therefore we will manipulate them to confirm their value in reducing relapse rates and improve addiction treatments.
- Deciphering neuroimmune interactions in alcohol intake in mouse model of intermittent access in male and femalePublication . Pacheco, Raquel; Canedo, Teresa; Rodrigues, Ana M.; Moreira, Joana; Relvas, João B.; Socodato, Renato; Summavielle, Teresa; Summavielle, TeresaExcessive alcohol consumption continues to pose a significant global health challenge, with detrimental effects on millions of individuals. Our laboratory has shown that alcohol exposure triggers reactive changes in astrocytes, including alterations in gene expression, activity, and proliferation, while also affecting microglial morphology and immune responses. We are to characterizing the effects of chronic alcohol consumption using a wellestablished voluntary alcohol drinking model in adult mice, to investigate the impact of chronic alcohol exposure on the prefrontal cortex (PFC), focusing on glial cell morphology, synaptic density, and behaviour. Mice are exposed to intermittent “every-other-day” (EOD) access to alcohol 15% (v/v) for 3 weeks, and behaviourally tested for anxiety, depression and memory, before sacrifice at 21 days of alcohol, or at 7 days of withdrawal. Brains were processed for glial cell analysis. Our preliminary findings revealed sex-specific responses following chronic alcohol exposure. Male mice exhibited increased astrocyte volume in the ventromedial PFC (vmPFC) and hyper-ramification in the ventrolateral PFC (vlPFC), whereas females displayed reductions in astrocyte size and complexity. Microglia morphology also differed between sexes, with females showing increased cell volume and males displaying reduced microglial volume in the vlPFC. These results suggest distinctive immune and synaptic responses to ethanol in males and females. Of note, we observed heightened inhibitory synapse density in the male PFC, while females exhibited increased excitatory synapse density. We are now conducting a proteomic analysis of PFC synaptosomes to identify important molecular targets in the crosstalk between neuros and glial cells. With this work we expect to clarify the complex interplay between chronic ethanol exposure, sex, and PFC function, find also new targets for innovative therapeutic approaches.
- Deciphering the astrocytic and synaptic changes under chronic alcohol exposure using a self-administration paradigmPublication . Rodrigues, Ana Margarida; Canedo, Teresa; Terceiro, Ana Filipa; Tedim-Moreira, Joana; Silva, Ana Isabel; Magalhães, Ana; Relvas, João; Summavielle, TeresaDrug abuse is characterized by a compulsive and persistent drug-seeking behaviour, despite the harmful emotional, physical and social consequences. Our laboratory has previously found that the neuronal-glial crosstalk is critical in relaying the changes caused by acute exposure to psychoactive drugs through neuroimmune mechanisms. We have also reported that microglia can engulf postsynaptic components in the prefrontal cortex (PFC) of mice after repeated alcohol exposure and this led to increased anxiety in mice. The adverse effects of alcohol on the central nervous system (CNS) are well described, with astrocytes becoming reactive and displaying changes in gene expression, activity and proliferation. However, the mechanisms involved are not yet fully understood. We are currently characterizing the astrocytic response under chronic alcohol consumption, taking into account the crucial interaction between neuronal and glial cells in the development and maintenance of addiction. Using a well-established voluntary alcohol drinking paradigm, we are evaluating alcohol-associated changes in PFC astrocytes, synapses and their behavioural correlates. Our preliminary results indicate similar alcohol consumption patterns between males and females, however, males, but not females, present altered weight gain and experience a significant increase in inhibitory synapse density after chronic exposure to ethanol when compared to the control group. Our work is contributing to a better understanding of the impact of chronic alcohol intake and may lead to the development of new strategies for pharmacological intervention in drug addiction, based on the targets identified as critical for the neuronal-glial crosstalk.
- IL-10 and Cdc42 as critical modulators in methamphtamine-induced neuroinflammationPublication . Silva, Ana Isabel; Socodato, Renato; Pinto, Carolina; Terceiro, Ana Filipa; Canedo, Teresa; Relvas, João Bettencourt; Saraiva, Margarida; Summavielle, Teresa; Summavielle, TeresaPsychoactive substances, such as Methamphetamine (Meth), can induce complex neuroinflammatory responses that modulate the neuron-glia cross talk and strongly affect behavioral responses. Recently we have reported that Meth stimulates astrocytes to release tumor necrosis factor (TNF) and glutamate, leading to microglial activation, microgliosis and loss of risk-assessment. Here, we started by investigating the anti-inflammatory power the cytokine interleukin-10 (IL-10), resorting to astrocyte and microglia primary transfected with different FRET probes and exposed to Meth (100µM), to elucidate the mechanisms involved. Then after, we confirmed these results in vivo, by employing a transgenic mouse model that overexpresses IL-10 (pMT-10), in time-controlled manner, and administering a binge Meth dosing (4 x 5mg/kg, with 2h intervals). In vitro, our findings reveal that the presence of recombinant IL-10 (rIL-10) counteracts Meth-induced excessive glutamate release in astrocytes, which significantly reduced microglial activation. This reduction was associated with the modulation of astrocytic intracellular calcium (Ca2+) dynamics, particularly by restricting the release of Ca2+ from the endoplasmic reticulum to the cytoplasm. Furthermore, we identify the small Rho GTPase Cdc42 as a crucial intermediary in the astrocyte-to-microglia communication pathway under Meth. In vivo, we observed that IL-10 overexpressing prevented Meth-induced neuroinflammation, microgliosis and Meth-induced behavioral changes. These findings enhance our understanding of Meth-related neuroinflammatory mechanisms, suggesting IL-10 and Cdc42 as putative therapeutic targets, and strengthen the view of a neuroimmune nature for addiction.
- IL-10 and Cdc42 modulate astrocyte-mediated microglia activation in methamphetamine-induced neuroinflammationPublication . Silva, Ana Isabel; Socodato, Renato; Pinto, Carolina; Terceiro, Ana Filipa; Canedo, Teresa; Relvas, João Bettencourt; Saraiva, Margarida; Summavielle, TeresaMethamphetamine (Meth) use is known to induce complex neuroinflammatory responses, particularly involving astrocytes and microglia. Building upon our previous research, which demonstrated that Meth stimulates astrocytes to release tumor necrosis factor (TNF) and glutamate, leading to microglial activation, this study investigates the role of the anti-inflammatory cytokine interleukin-10 (IL-10) in this process. Our findings reveal that the presence of recombinant IL-10 (rIL-10) counteracts Meth-induced excessive glutamate release in astrocyte cultures, which significantly reduces microglial activation. This reduction is associated with the modulation of astrocytic intracellular calcium (Ca2+) dynamics, particularly by restricting the release of Ca2+ from the endoplasmic reticulum to the cytoplasm. Furthermore, we identify the small Rho GTPase Cdc42 as a crucial intermediary in the astrocyte-to-microglia communication pathway under Meth exposure. By employing a transgenic mouse model that overexpresses IL-10 (pMT-10), we also demonstrate in vivo that IL-10 prevents Meth-induced neuroinflammation. These findings not only enhance our understanding of Meth-related neuroinflammatory mechanisms, but also suggest IL-10 and Cdc42 as putative therapeutic targets for treating Meth-induced neuroinflammation.
- Methamphetamine activates rac1 in striatal microgliaPublication . Terceiro, Ana Filipa; Canedo, Teresa; Silva, Ana Isabel; Magalhães, Ana; Relvas, João; Summavielle, Teresa; Summavielle, TeresaMethamphetamine (Meth), a powerful psychostimulant, induces profound synaptic and morphological alterations alongside with detrimental neuroinflammatory responses, in the brain reward system. Yet, the mechanisms regulating these processes in microglial cells are not clear. We have previously shown that exposing WT mice to Meth (4x5mg/kg, 2h intervals) induces microgliosis concomitant with decreased microglia cell volume and ramification. Furthermore, psychostimulants are known to induce structural plasticity mechanisms in neurons, and Rho GTPases, important regulators of the actin cytoskeleton, are involved in these responses. Here, we evaluate if Rho GTPases, specifically rhoA, rac1 and cdc42, are critical in the response to Meth in microglia. Exposing WT mice to the samepattern of Meth administration, we found an increase in the activation of rac1 in the striatum, 15 min following the last administration of Meth. To further explore these results, we then used a conditional mice model for ablation of rac1 in adult microglia (Rac1fl/fl:Cx3cr1CreER+) and exposed these mutants to the same pattern of Meth administration. We found that rac1 ablation is sufficient to prevent Meth-induced morphological alterations in the striatum. Currently, we are assessing whether ablation of rac1 is also sufficient to prevent the neuroinflammatory response induced by Meth. Overall, we identified rac1 as a novel target of Meth in microglial cells. With these results, we expect to clarifyif targeting Rho GTPases may contribute to improving the treatment of addictive disorders.
- Microglia dysfunction caused by the loss of rhoa disrupts neuronal physiology and leads to neurodegenerationPublication . Socodato, Renato; Portugal, Camila C.; Canedo, Teresa; Rodrigues, Artur; Almeida, Tiago O.; Henriques, Joana F.; Vaz, Sandra H.; Magalhães, João; Silva, Cátia M.; Baptista, Filipa I.; Alves, Renata L.; Coelho-Santos, Vanessa; Silva, Ana Paula; Paes-de-Carvalho, Roberto; Magalhães, Ana; Brakebusch, Cord; Sebastião, Ana M.; Summavielle, Teresa; Ambrósio, António F.; Relvas, João B.Nervous tissue homeostasis requires the regulation of microglia activity. Using conditional gene targeting in mice, we demonstrate that genetic ablation of the small GTPase Rhoa in adult microglia is sufficient to trigger spontaneous microglia activation, producing a neurological phenotype (including synapse and neuron loss, impairment of long-term potentiation [LTP], formation of β-amyloid plaques, and memory deficits). Mechanistically, loss of Rhoa in microglia triggers Src activation and Src-mediated tumor necrosis factor (TNF) production, leading to excitotoxic glutamate secretion. Inhibiting Src in microglia Rhoa-deficient mice attenuates microglia dysregulation and the ensuing neurological phenotype. We also find that the Rhoa/Src signaling pathway is disrupted in microglia of the APP/PS1 mouse model of Alzheimer disease and that low doses of Aβ oligomers trigger microglia neurotoxic polarization through the disruption of Rhoa-to-Src signaling. Overall, our results indicate that disturbing Rho GTPase signaling in microglia can directly cause neurodegeneration.
- Microglial RAC1 drives experience-dependent brain plasticityPublication . Almeida, Tiago O.; Portugal, Camila C.; Santos, Evelyn C. S.; Moreira, Joana Tedim; Ferreira, João Galvão; Canedo, Teresa; Magalhães, Ana; Summavielle, Teresa; Summavielle, TeresaMicroglia, the immune defenders of the brain, continuously extend and retract their processes to sense and decipher their local environment. This includes interactions with synapses to maintain brain homeostasis. To do this, microglia rely on the actin cytoskeleton and subsequent intracellular signaling, which is adapted in response to external signals released by cells undergoing intense synaptic activity. Thus, proteins that regulate actin cytoskeleton dynamics, intracellular trafficking, and integration of extracellular signaling, such as RhoA, Rac1 and Cdc42 from the Rho GTPase family, are good candidates to govern microglial sensing capacity and homeostasis. In this study, using conditional cellspecific gene targeting in mice combined with multi-omics approaches, immunofluorescence, and behavioral tests we aimed to identify the roles of Rho GTPase Rac1 in microglia homeostasis. We demonstrate that the Rho GTPase Rac1 is essential for microglia to sense and interpret their local microenvironment. This impacts the microglia-synapse crosstalk that is required for experiencedependent plasticity, a fundamental brain property impaired in several neuropsychiatric disorders. Furthermore, phosphoproteomics profiling of microglia isolated from mice exposed to an environmental enrichment protocol (known to induce experience-dependent synaptic plasticity and cognitive performance) detects a large modulation of Rho GTPase signaling, predominantly of Rac1. Additionally, our results show that environmental enrichment likely requires tight regulation of Rho GTPase-dependent pathways. Ablation of microglial Rac1 affected pathways involved in microglia-synapse communication, disrupted experience-dependent synaptic remodeling and blocked the gains in learning, memory, and sociability induced by environmental enrichment. Overall, our results place microglial Rac1 as a central regulator of pathways involved in the microglia-synapse crosstalk required for experience-dependent synaptic plasticity and cognitive performance, suggesting that modulation of Rho GTPase signaling in microglia might be a useful strategy to boost neuroplasticity in health and disease.
- Microglial Rac1 is essential for experience-dependent brain plasticity and cognitive performancePublication . Socodato, Renato; Almeida, Tiago O.; Portugal, Camila C.; Santos, Evelyn C.S.; Tedim-Moreira, Joana; Ferreira, João Galvão; Canedo, Teresa; Baptista, Filipa I.; Magalhães, Ana; Ambrósio, António F.; Brakebusch, Cord; Rubinstein, Boris; Moreira, Irina S.; Summavielle, Teresa; Pinto, Inês Mendes; Relvas, João B.Microglia, the largest population of brain immune cells, continuously interact with synapses to maintain brain homeostasis. In this study, we use conditional cell-specific gene targeting in mice with multi-omics approaches and demonstrate that the RhoGTPase Rac1 is an essential requirement for microglia to sense and interpret the brain microenvironment. This is crucial for microglia-synapse crosstalk that drives experience-dependent plasticity, a fundamental brain property impaired in several neuropsychiatric disorders. Phosphoproteomics profiling detects a large modulation of RhoGTPase signaling, predominantly of Rac1, in microglia of mice exposed to an environmental enrichment protocol known to induce experience-dependent brain plasticity and cognitive performance. Ablation of microglial Rac1 affects pathways involved in microglia-synapse communication, disrupts experience-dependent synaptic remodeling, and blocks the gains in learning, memory, and sociability induced by environmental enrichment. Our results reveal microglial Rac1 as a central regulator of pathways involved in the microglia-synapse crosstalk required for experience-dependent synaptic plasticity and cognitive performance.