SIRT1 activation attenuates microglia-mediated synaptic engulfment in postoperative cognitive
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PROVIDER: PRJNA890228 | ENA |
REPOSITORIES: ENA
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Project description:Background: Postoperative cognitive dysfunction (POCD) is a debilitating neurological complication in surgical patients. Current research has focused mainly on microglial activation, but less is known about the resultant neuronal synaptic changes. Recent studies have suggested that silent information regulator 1 (SIRT1) plays a critical role in several different neurological disorders via its involvement in microglial activation. In this study, we evaluate the effects of SIRT1 activation in a POCD mouse model. Methods: Exploratory laparotomy was performed in mice aged 12-14 months under sevoflurane anesthesia to establish our animal POCD model. Transcriptional changes in the hippocampus after anesthesia and surgery were evaluated by RNA sequencing. SIRT1 expression was verified by Western Blot. Mice were treated with SIRT1 agonist SRT1720 or vehicle after surgery. Changes in microglia morphology, microglial phagocytosis, presence of dystrophic neurites, and dendritic spine density were evaluated. Cognitive performance was evaluated using the Y maze and Morris water maze. Results: SIRT1 expression levels were downregulated in POCD. Exposure to anesthesia and surgery lead to alteration in microglia morphology, increased synaptic engulfment, dendritic spine loss, and cognitive deficits. These effects were alleviated by SRT1720 administration. Conclusion: This study suggests an important neuroprotective role for SIRT1 in POCD pathogenesis. Increasing SIRT1 function represents a promising therapeutic strategy for prevention and treatment of POCD.
2022-12-09 | GSE215410 | GEO
Project description:BackgroundPostoperative cognitive dysfunction (POCD) is a debilitating neurological complication in surgical patients. Current research has focused mainly on microglial activation, but less is known about the resultant neuronal synaptic changes. Recent studies have suggested that Sirtuin-1 (SIRT1) plays a critical role in several different neurological disorders via its involvement in microglial activation. In this study, we evaluate the effects of SIRT1 activation in a POCD mouse model.Materials and methodsExploratory laparotomy was performed in mice aged 12-14 months under sevoflurane anesthesia to establish our animal POCD model. Transcriptional changes in the hippocampus after anesthesia and surgery were evaluated by RNA sequencing. SIRT1 expression was verified by Western Blot. Mice were treated with SIRT1 agonist SRT1720 or vehicle after surgery. Changes in microglia morphology, microglial phagocytosis, presence of dystrophic neurites, and dendritic spine density were evaluated. Cognitive performance was evaluated using the Y maze and Morris water maze (MWM).ResultsSirtuin-1 expression levels were downregulated in POCD. Exposure to anesthesia and surgery lead to alteration in microglia morphology, increased synaptic engulfment, dendritic spine loss, and cognitive deficits. These effects were alleviated by SRT1720 administration.ConclusionThis study suggests an important neuroprotective role for SIRT1 in POCD pathogenesis. Increasing SIRT1 function represents a promising therapeutic strategy for prevention and treatment of POCD.
| S-EPMC9685341 | biostudies-literature
Project description:This study investigates the roles of neurons, microglia, astrocytes, and oligodendrocytes in the pathogenesis of postoperative cognitive impairment, focusing on a dysregulated glia-neuron cycle. We utilized 18-month male C57BL/6 mice to model this condition, conducting single-cell RNA sequencing in the hippocampus to explore the neuroglial interactions and their implications in neuroinflammation, synaptic dysfunction, and myelin loss. This dataset includes transcriptomic profiles aimed at decoding the cellular communication in aged hippocampal cells and assessing the impact of therapeutic interventions on postoperative cognitive decline.
2024-11-14 | GSE267933 | GEO
Project description:Sirt1, a NAD-dependent deacetylase, has been shown involved in many complex biological functions. We previously demonstrated that Sirt-1 gain of function is neuroprotective in a model of neurodegenenration. We recently found that Sirt1 loss of function (Sirt1Î mouse) impairs learning, memory, and synaptic plasticity. We used microarray screening to identify potential miRNAs that may be regulated by Sirt1 and ivolved in learning and memory. Total RNA from the hippocampus of SIRT1Î and control mice was extracted and used for microRNA expression level evaluation. Two group experiment, in duplicates. Each sample is compared to a common reference sample, comprised of an equal mixture of all 4 experimental samples.
2010-07-29 | E-GEOD-22530 | biostudies-arrayexpress
Project description:Sirt1, a NAD-dependent deacetylase, has been shown involved in many complex biological functions. We previously demonstrated that Sirt-1 gain of function is neuroprotective in a model of neurodegenenration. We recently found that Sirt1 loss of function (Sirt1Δ mouse) impairs learning, memory, and synaptic plasticity. We used microarray screening to identify potential miRNAs that may be regulated by Sirt1 and ivolved in learning and memory. Total RNA from the hippocampus of SIRT1Δ and control mice was extracted and used for microRNA expression level evaluation.
2010-06-24 | GSE22530 | GEO
Project description:Postoperative cognitive dysfunction (POCD) is one of the severe complications inducing low life quality and high mortality after surgery, especially in elderly patients.Here we probed differentially expressed circRNAs using microarray assay in POCD patients, aiming to find potential key circRNAs related to the occurrence of POCD. Subsequently, ten dysregulated circRNAs were confirmed via quantitative real-time polymerase chain reaction (qRT-PCR) in 10 paired samples. Then, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to probe the vital functions of dysregulated genes.
2020-07-14 | GSE147277 | GEO
Project description:We aim to investigate the role of renal Sirt1 on albuminuria. To further development of our gene expression approach to biodosimetry, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish between wild type(C57BL/6J) mice treated with streptozotocin (WT+STZ) and Sirt1-overexpressing transgenic mice treated with streptozotocin (TG+STZ) mice. To elucidate the molecular mechanisms underlying the amelioration of albuminuria by our TG (Sirt1-overexpressing transgenic) mice, we performed DNA microarray analysis using micro-dissected glomerular regions to examine the differences in gene expression between WT+STZ and TG+STZ mice.
2018-03-08 | GSE50140 | GEO
Project description:Postoperative cognitive dysfunction (POCD) is a common postoperative complication observed in elderly patients. However, the underlying mechanisms of POCD remain unclear. MicroRNAs (miRNAs) which are involved in the pathogenesis of neurodegenerative diseases, may also affect POCD. To identify the relevant potential mechanisms, in this study, we comprehensively compared the expression profiles of miRNAs in 5 hippocampal tissues from POCD mice and 5 hippocampal tissues from control mice by microarray. A total of 128 miRNAs, whose expression changed significantly, were identified. Four miRNAs were confirmed by quantitative real-time polymerase chain reaction (PCR) in 10 paired samples. Gene Ontology (GO) and KEGG pathway enrichment analyses were performed to explore the principal functions of the deregulated genes. We predicted the potential targets of miRNAs by using bioinformatics methods. In summary, novel miRNAs were identified as potential biomarkers and therapeutic targets for POCD treatment.
2017-02-20 | GSE95070 | GEO
Project description:Aging is the predominant risk factor for neurodegenerative diseases. One key phenotype as brain ages is the aberrant innate immune response characterized by proinflammation. However, the molecular mechanisms underlying aging-associated proinflammation are poorly defined. Whether chronic inflammation plays a causal role in cognitive decline in aging and neurodegeneration has not been established. Here we established a mechanistic link between chronic inflammation and aging microglia, and demonstrated a causal role of aging microglia in neurodegenerative cognitive deficits. Expression of microglial SIRT1 reduces with the aging of microglia. Genetic reduction of microglial SIRT1 elevates IL-1β selectively, and exacerbates cognitive deficits in aging and in transgenic mouse models of frontotemporal dementia (FTD). Interestingly, the selective activation of IL-1β transcription by SIRT1 deficiency is likely mediated through hypomethylating the proximal promoter of IL-1β. Consistent with our findings in mice, selective hypomethylation of IL-1β at two CpG sites are found in normal aging humans and demented patients with tauopathy. Our findings reveal a novel epigenetic mechanism in aging microglia that contributes to cognitive deficits in neurodegenerative diseases. Study of changes related to alterations of SIRT1 levels in microglia of young and aged animals and in models of neurodegenerative dementia
2014-10-01 | E-GEOD-56452 | biostudies-arrayexpress
Project description:Phagocytosis of synaptic debris by microglia is critical for CNS development and homeostasis. Less well understood are microglial functions in injured adult brain, where their presumed role is clearance of neuronal debris. Assay of this process is challenging, because the resulting peripheral myeloid-cell engraftment is difficult to dissociate from microglial clearance. The model used here, optic nerve crush injury in adult mouse, stimulates rapid engulfment of synaptic material by microglia residing in the lateral geniculate nucleus (LGN), sufficiently distant from the injury to preclude peripheral-cell engraftment. Pre-injury pharmacological depletion of microglia causes post-injury accumulation of synaptic debris, suggesting that these, not astrocytes, are the dominant post-injury phagocytes. Genetic and pharmacological manipulations revealed that neuronal activity, which regulates microglial engulfment of synaptic debris in development, does not do so in post-injury synaptic material clearance in adulthood, where such clearance depends instead on axonal integrity. RNAseq reveals C1q involvement in clearance of debris by LGN-resident microglia, supporting our finding of its impaired clearance in C1qa-/- and Itgam-/- mice. Our results demonstrate how neurodegenerative debris is cleared by microglial phagocytosis, and offer a model for assaying microglial phagocytic activity and studying its mechanisms and physiological roles.
2018-06-07 | GSE107635 | GEO