Project description:Traumatic spinal cord injury (SCI) triggers a neuro-inflammatory response dominated by tissue-resident microglia and monocyte derived macrophages (MDMs). Since activated microglia and MDMs are morphologically identical and express similar phenotypic markers in vivo, identifying injury responses specifically coordinated by microglia has historically been challenging. Here, we pharmacologically depleted microglia and use anatomical, histopathological, tract tracing, bulk and single cell RNA sequencing to reveal the cellular and molecular responses to SCI controlled by microglia. We show that microglia are vital for SCI recovery and coordinate injury responses in CNS-resident glia and infiltrating leukocytes. Depleting microglia exacerbates tissue damage and worsens functional recovery. Conversely, restoring select microglia-dependent signaling axes, identified through sequencing data, in microglia depleted mice prevents secondary damage and promotes recovery. Additional bioinformatics analyses reveal that optimal repair after SCI and likely other forms of neurological disease, might be achieved by co-opting key ligand-receptor interactions between microglia, astrocytes and MDMs.
Project description:Transcriptome analysis of spinal cord microglia and total spinal cord from Lewis rats intratracheally treated with PBS, neomycin or vancomycin.
Project description:To investigate the mechanism of electrical stimulation in the repair of spinal cord injury, we established a rat model of spinal cord injury. Then, we used RNA-SEQ data obtained from ES treatment and 6 different rat models of spinal cord injury for gene expression profile analysis.
Project description:To elucidate differential gene expression pattern in atopic diathesis model mice spinal cord microglia compared to normal mice. Sort microglia from atopic diathesis model mice and control mice, extract RNA and subjected to RNA array assay.
Project description:Inflammation after injury of the central nervous system (CNS) is increasingly viewed as a therapeutic target. However, comparative studies in different CNS compartments are sparse. To date only few studies based on immunohistochemical data and all referring to mechanical injury have directly compared inflammation in different CNS compartments. These studies revealed that inflammation is more pronounced in spinal cord than in brain. Therefore, it is unclear whether concepts and treatments established in the cerebral cortex can be transferred to spinal cord lesions and vice versa or whether immunological treatments must be adapted to different CNS compartments. By use of transcriptomic and flow cytometry analysis of equally sized photothrombotically induced lesions in the cerebral cortex and the spinal cord, we could document an overall comparable inflammatory reaction and repair activity in brain and spinal cord between day 1 and day 7 after ischemia. However, remyelination was increased after cerebral versus spinal cord ischemia which is in line with increased remyelination in grey matter in previous analyses and was accompanied by microglia dominated inflammation opposed to monocytes/macrophages dominated inflammation after spinal cord ischemia. Interestingly remyelination could be reduced by microglia and not hematogenous macrophage depletion. Our results show that despite different cellular composition of the postischemic infiltrate the inflammatory response in cerebral cortex and spinal cord are comparable between day 1 and day 7. A striking difference was higher remyelination capacity in the cerebral cortex, which seems to be supported by microglia dominance.
Project description:We investigated the gene expression profile of monocyte-derived macrophages and microglia following spinal cord injury. Moreover, we investigated the gene expression profole of M-CSF induced macrophages and new-born derived microglia following TGFb1 treatment. monocyte-derived macrophages and microglia following spinal cord injury M-CSF induced macrophages and new-born derived microglia following TGFb1 treatment
Project description:Aggressive inflammation and excessive scar formation are the main cause to the difficulty of neural tissue repair after spinal cord injury (SCI). Microglia and astrocytes act as important role in this micro-environment of SCI and there is cross regulation between microglia and astrocytes. After SCI, MG0 polarized into MG1 and MG3 which were belong to pro-inflammatory phenotype microglia; Naive astrocytes polarized into Reactive and Scar-forming astrocytes. Growth arrest-specific 6 (Gas6) and its receptor Axl was declined in all these cells after SCI. In vitro study, Gas6 had the negative effect on cytotoxic astrocytes and pro-inflammatory microglia polarization and even the cross regulation between cytotoxic astrocytes and pro-inflammatory microglia. Further mechanism study indicated that Gas6 suppressed cytotoxic phenotype polarization of astrocytes through inhibited the activation of YES-associated protein (YAP) signal pathway and suppressed pro-inflammatory phenotype polarization of microglia through inhibited the activation of NF-κB/p65 and JAK/Stat3 signal pathways. In vivo study, Gas6 treatment suppressed cytotoxic astrocytes and pro-inflammatory microglia polarization at the injured site of spinal cord to facilitate tissue repair and loco-motor recovery.
Project description:RNA-seq analysis of microglia following spinal cord injury demonstrated that microglia response is driven by time after injury but not lesion severity.