Alcohol abuse adversely affects the lives of millions of people worldwide. Deficits in synaptic transmission and in microglial function are commonly found in human alcohol abusers and in animal models of alcohol intoxication. Here, we found that a protocol simulating chronic binge drinking in male mice resulted in aberrant synaptic pruning and substantial loss of excitatory synapses in the prefrontal cortex, which resulted in increased anxiety-like behavior. Mechanistically, alcohol intake increased the engulfment capacity of microglia in a manner dependent on the kinase Src, the subsequent activation of the transcription factor NF-κB, and the consequent production of the proinflammatory cytokine TNF. Pharmacological blockade of Src activation or of TNF production in microglia, genetic ablation of Tnf, or conditional ablation of microglia attenuated aberrant synaptic pruning, thereby preventing the neuronal and behavioral effects of the alcohol. Our data suggest that aberrant pruning of excitatory synapses by microglia may disrupt synaptic transmission in response to alcohol abuse.
Bladder cancer (BlCa) is a common malignancy with significant morbidity and mortality. Current diagnostic methods are invasive and costly, showing the need for newer biomarkers. Although several epigenetic-based biomarkers have been proposed, their ability to discriminate BlCa from common benign conditions of the urinary tract, especially inflammatory diseases, has not been adequately explored. Herein, we sought to determine whether VIMme and miR663ame might accurately discriminate those two conditions, using a multiplex test. Performance of VIMme and miR663ame in tissue samples and urines in testing set confirmed previous results (96.3% sensitivity, 88.2% specificity, area under de curve (AUC) 0.98 and 92.6% sensitivity, 75% specificity, AUC 0.83, respectively). In the validation sets, VIMme-miR663ame multiplex test in urine discriminated BlCa patients from healthy donors or patients with inflammatory conditions, with 87% sensitivity, 86% specificity and 80% sensitivity, 75% specificity, respectively. Furthermore, positive likelihood ratio (LR) of 2.41 and negative LR of 0.21 were also disclosed. Compared to urinary cytology, VIMme-miR663ame multiplex panel correctly detected 87% of the analysed cases, whereas cytology only forecasted 41%. Furthermore, high miR663ame independently predicted worse clinical outcome, especially in patients with invasive BlCa. We concluded that the implementation of this panel might better stratify patients for confirmatory, invasive examinations, ultimately improving the cost-effectiveness of BlCa diagnosis and management. Moreover, miR663ame analysis might provide relevant information for patient monitoring, identifying patients at higher risk for cancer progression.
20Alcohol use adversely impacts the life of millions of people worldwide. Deficits 21 in synaptic transmission and in microglial function are common findings in human 22 alcohol users and in animal models of alcohol intoxication. Here, we show that 23 alcohol intake over ten consecutive days resulted in substantial loss of excitatory 24 synapse in the prefrontal cortex, a consequence of aberrant synaptic pruning, which 25 led to increased anxiety-like behavior. Mechanistically, these effects of alcohol intake 26 were mediated by a detrimental increase of microglia engulfment capacity via Src-27 dependent activation of NFkB and consequent TNF production. Accordingly, 28 pharmacological blockade of Src activation or TNF production by microglia, genetic 29 ablation of TNF, or diphtheria toxin-mediated conditional ablation of microglia 30 attenuated aberrant synaptic pruning preventing excitatory synapse loss and anxiety-31 like behavior. Overall, our data suggest that aberrant pruning of excitatory synapses 32 by microglia might disrupt synaptic transmission during alcohol use.33 34 Introduction 35 Alcohol use is associated with pathophysiological changes in the brain and in 36 peripheral organs often resulting in life-threatening conditions. Central nervous 37 system (CNS) exposure to alcohol often leads to behavioral deficits (including 38 anxiety, cognitive decline and motor dysfunction) and impairment of synaptic 39 function, a major hallmark of alcohol use, likely underlies such behavioral deficits.40 Indeed, alcohol detrimentally impacts the pre and post-synaptic compartments and 41 the secretion/recycling of neurotransmitters, ultimately leading to the disruption of 42 excitatory and inhibitory neurotransmission [1,2]. This detrimental effect of alcohol on 43 synapses can be contributed by a well-established action of alcohol on neurons and 44 potentially through an underappreciated action of alcohol on glial cells [3].45 Microglia, the major innate immune cell population in the brain [4], maintain 46 nervous tissue homeostasis, surveilling the CNS parenchyma by continuously 47 extending and retracting their cellular processes, monitoring for tissue damage or 48 infections and checking the functional status of synapses [5]. Following CNS tissue 49 damage or infection, microglia become activated, changing their morphology (into a 50 more ameboid shape), phagocytic capacity and transcriptional profile in order to 51 restore tissue homeostasis [5]. In many neuropsychiatry disorders, however, 52 microglia immune function becomes dysregulated, often leading to overproduction of 53 inflammatory mediators and exacerbated phagocytic activity, which can be 54 detrimental to synapses and behavior [6,7]. 55In human alcohol abusers [8] and in animal models of alcohol intoxication [9] 56 alteration of microglial function is associated with neuroimmune activation [10,11] 57 and might be directly involved in some of the neurotoxic and adverse behavioral 58 effects of alcohol intake [12]. Indeed, it is thought that inn...
Microglia modulate synaptic activity, essential for context-dependent cognitive performance, allowing organism-level adaptations to different environmental scenarios. Yet, the microglial molecular drivers required for synaptic remodeling related to cognitive performance remain largely elusive. Here, combining conditional gene targeting, single-cell live imaging, RNA-seq, high-throughput proteomics, systems biology, and animal behavior, we mapped a molecular nexus between microglia and synapses that instruct cognitive performance. Specifically, we found that microglia use the RhoGTPase Rac1 as a relay switch to sense the brain microenvironment and drive synaptic remodeling required for experience-dependent sociability and learning related to memory. Targeting this microglial relay modifies context-dependent cognitive performance.
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