Project description:We performed bulk transcriptomic analysis to examine how glycation-modified collagen further impacts the function of meningeal fibroblasts. We preprocessed raw data to align bulk RNA-seq using STAR (detailed in Experimental Section) and identified differentially expressed genes (DEGs), especially ECM-related gene sets.
Project description:Collagen is a prominent target of nonenzymatic glycation, which is a hallmark of aging and causes functional alteration of the matrix. Here, we uncover glycation-mediated structural and functional changes in the collagen-enriched meningeal membrane of the human and mouse brain. Using an in vitro culture platform mimicking the meningeal membrane composed of fibrillar collagen, we showed that the accumulation of advanced glycation end products (AGEs) in the collagen membrane is responsible for glycation-mediated matrix remodeling. These changes influence fibroblast-matrix interactions, inducing cell-mediated ECM remodeling. The adherence of meningeal fibroblasts to the glycated collagen membrane was mediated by the discoidin domain-containing receptor 2 (DDR2), whereas integrin-mediated adhesion was inhibited. A-kinase anchoring protein 12 (AKAP12)-positive meningeal fibroblasts in the meningeal membrane of aged mice exhibited substantially increased expression of DDR2 and depletion of integrin beta-1 (ITGB1). In the glycated collagen membrane, meningeal fibroblasts increased the expression of matrix metalloproteinase 14 (MMP14) and less tissue inhibitor of metalloproteinase-1 (TIMP1). In contrast, the cells exhibited decreased expression of type I collagen (COL1A1). These results suggest that glycation modification by meningeal fibroblasts is intimately linked to aging-related structural and functional alterations in the meningeal membrane.
Project description:Emerging evidence suggests that the meningeal compartment plays instrumental roles in various neurological disorders and can modulate neurodevelopment and behavior. While this has sparked great interest in the meninges, we still lack fundamental knowledge about meningeal biology. Here, we utilized high-throughput RNA sequencing (RNA-seq) techniques to investigate the transcriptional response of the meninges to traumatic brain injury (TBI) and aging in the sub-acute and chronic time frames. Using single-cell RNA sequencing (scRNA-seq), we first explored how mild TBI affects the cellular and transcriptional landscape in the meninges in young mice at one week post-injury. Then, using bulk RNA sequencing, we assessed the differential long-term outcomes between young and aged mice following a TBI. In our scRNA-seq studies, we found that mild head trauma leads to an activation of type I interferon (IFN) signature genes in meningeal macrophages as well as the mobilization of multiple distinct sub-populations of meningeal macrophages expressing hallmarks of either classically activated or wound healing macrophages. We also revealed that dural fibroblasts in the meningeal compartment are highly responsive to TBI, and pathway analysis identified differential expression of genes linked to various neurodegenerative diseases. For reasons that remain poorly understood, the elderly are especially vulnerable to head trauma, where even mild injuries can lead to rapid cognitive decline and devastating neuropathology. To better understand the differential outcomes between the young and the elderly following brain injury, we performed bulk RNA-seq on young and aged meninges from mice that had received a mild TBI or Sham treatment 1.5 months prior. Notably, we found that aging alone induced massive upregulation of meningeal genes involved in antibody production by B cells and type I IFN signaling. Following injury, the meningeal transcriptome had largely returned to its pre-injury signature in young mice. In stark contrast, aged TBI mice still exhibited massive upregulation of immune-related genes and markedly reduced expression of genes involved in extracellular matrix remodeling and maintenance of cellular junctions. Overall, these findings illustrate the dynamic and complex transcriptional response of the meninges to mild head trauma. Moreover, we also reveal how aging modulates the meningeal response to TBI.
Project description:Emerging evidence suggests that the meningeal compartment plays instrumental roles in various neurological disorders and can modulate neurodevelopment and behavior. While this has sparked great interest in the meninges, we still lack fundamental knowledge about meningeal biology. Here, we utilized high-throughput RNA sequencing (RNA-seq) techniques to investigate the transcriptional response of the meninges to traumatic brain injury (TBI) and aging in the sub-acute and chronic time frames. Using single-cell RNA sequencing (scRNA-seq), we first explored how mild TBI affects the cellular and transcriptional landscape in the meninges in young mice at one week post-injury. Then, using bulk RNA sequencing, we assessed the differential long-term outcomes between young and aged mice following a TBI. In our scRNA-seq studies, we found that mild head trauma leads to an activation of type I interferon (IFN) signature genes in meningeal macrophages as well as the mobilization of multiple distinct sub-populations of meningeal macrophages expressing hallmarks of either classically activated or wound healing macrophages. We also revealed that dural fibroblasts in the meningeal compartment are highly responsive to TBI, and pathway analysis identified differential expression of genes linked to various neurodegenerative diseases. For reasons that remain poorly understood, the elderly are especially vulnerable to head trauma, where even mild injuries can lead to rapid cognitive decline and devastating neuropathology. To better understand the differential outcomes between the young and the elderly following brain injury, we performed bulk RNA-seq on young and aged meninges from mice that had received a mild TBI or Sham treatment 1.5 months prior. Notably, we found that aging alone induced massive upregulation of meningeal genes involved in antibody production by B cells and type I IFN signaling. Following injury, the meningeal transcriptome had largely returned to its pre-injury signature in young mice. In stark contrast, aged TBI mice still exhibited massive upregulation of immune-related genes and markedly reduced expression of genes involved in extracellular matrix remodeling and maintenance of cellular junctions. Overall, these findings illustrate the dynamic and complex transcriptional response of the meninges to mild head trauma. Moreover, we also reveal how aging modulates the meningeal response to TBI.
Project description:The Bin/amphiphysin/Rvs (BAR) domain protein FAM92A1 is a multifunctional protein engaged in the regulation of mitochondrial ultrastructure and ciliogenesis. However, the physiological role of FAM92A1 in the brain, particularly in neurons with specialized membrane architecture, remains unexplored. Here, we demonstrate that FAM92A1 is prominently expressed in the brain and neurons during early mouse embryonic development. FAM92A1 knockout mice display brain morphology alterations, age-associated memory decline, and cognitive deficits. Moreover, the absence of FAM92A1 triggers hippocampal neuron degeneration and disrupts neuronal complexity and synaptic plasticity. Crucially, FAM92A1 deficiency leads to anomalies in membrane remodeling and disturbances in neuronal endocytic processes. Through analysis of the crystal structure of the FAM92A1 BAR domain, we unveil its intrinsic capability to form dimers, contributing to a distinctive curved conformation critical for membrane remodeling. By combining structural and molecular simulation, we further gain a comprehensive understanding of how FAM92A1 interacts with membranes to induce lipid clustering and generate membrane curvature. In summary, our study provides valuable insights into the physiological function of FAM92A1 in the brain. It uncovers the molecular mechanisms through which FAM92A1 regulates synaptic plasticity and neural function by influencing membrane remodeling and endocytic processes.
Project description:Postnatal brain neurogenesis in mammals is believed to be restricted to rare germinative remnants of the neuroepithelium. In this study, we discovered that, in the postnatal brain, a subset of embryonically derived progenitors is present in meningeal substructures. These cells migrate from the meningeal substructures to the retrosplenial and visual motor cortex and differentiate into (electrically) functional integrated neurons. Lineage tracing analysis revealed that this subset of neural progenitors originate largely from PDGFR+ cells. PDGFR-derived cells differentiate mostly into Satb2+ neurons in cortical layers I-IV. Thus, a reservoir of embryonically derived progenitors in the meninges contributes to postnatal cerebral cortical neurogenesis.
Project description:Glycation is a covalent protein modification that accumulates in the cellular environment. Histone proteins are particularly susceptible to glycation due to their extremely long half-lives and nucleophilic disordered tails. Here, we performed ATAC-seq on 293T cells cultured in the presence or absence of 0.5mM methylglioxal, a reactive glycolytic intermediate, for 12 hours. We demonstrate that methylglioxal treatment is associated with changes in histone occupancy and chromatin architecture globally.
Project description:Social creatures must attend to threat signals from conspecifics and respond appropriately, both behaviorally and physiologically. In this work, we show a threat-sensitive immune signaling that orchestrates psychological processes and is amenable to social modulation. Repeated encounters with socially-cued threats triggered neutrophil priming preferentially in males. Meningeal niche-specific neutrophil activity was correlated with attenuated defensive responses to cues. The neutrophil-specific membrane protein CD177 responded to threat-predicting social cues, and its genetic ablation abrogated male behavioral phenotypes. Neutrophil CD177 signaling facilitated optimal meningeal IFN-γ production, which blunted neural response to threatening stimuli by enhancing intrinsic GABAergic inhibition within the prelimbic cortex. Initiation of meningeal neutrophil-mediated IFN-γ signaling was sensitized by negative emotional states and governed by socially dependent androgen release. This male-biased hormone/neutrophil regulatory axis is seemingly conserved in humans. Our findings provide insights into how immune responses influence behavioral responses to threats, suggesting a possible neuroimmune basis of emotional regulation.