Project description:To investigate the plasticity of Lipolysaccharide (LPS) tolerance, we employed microarray profiling to analyse the gene expression profile in macrophage. Four macrophage populations were induced; Untreated macrophages (Control group), Acute response to LPS (LPS activation group), LPS tolerance (T – Tolerant group) and recovered (R = recovered macrophage group) Using transcriptional analysis we demonstrate that recovery from LPS tolerance (R – Recovery), as defined by cytokine gene expression, is associated with a global change in the transcriptional profile of macrophage. This data confirms that LPS tolerance is a transient state which results in induction of novel hybrid macrophage activation state with a unique transcriptional signature. Bone marrow derived macrophages were polarised into three activation states; Acute response to LPS (A), LPS tolerant (T) and recovered (R). Gene expression was measured at 4 hours post stimulation with LPS. Three independent experiments were performed to measure gene expression changes between each macrophage group.
Project description:To investigate the plasticity of Lipolysaccharide (LPS) tolerance, we employed microarray profiling to analyse the gene expression profile in macrophage. Four macrophage populations were induced; Untreated macrophages (Control group), Acute response to LPS (LPS activation group), LPS tolerance (T – Tolerant group) and recovered (R = recovered macrophage group) Using transcriptional analysis we demonstrate that recovery from LPS tolerance (R – Recovery), as defined by cytokine gene expression, is associated with a global change in the transcriptional profile of macrophage. This data confirms that LPS tolerance is a transient state which results in induction of novel hybrid macrophage activation state with a unique transcriptional signature.
Project description:ATAC-seq profiling of Nfat5 KO and wild type macrophages derived from bone marrow (primary cells), treated or not with Lipopolysaccharide (LPS).
Project description:Rehabilitative training is an effective method to promote recovery following spinal cord injury (SCI), with lower training efficacy observed in the chronic stage. The increased training efficacy during the subacute period is associated with an adaptive state induced by the SCI. A potential link is SCI-induced inflammation, which is elevated in the subacute period, and as injection of lipopolysaccharide (LPS) alongside training improves recovery in chronic SCI, suggesting LPS could reopen a window of plasticity late after injury. Microglia may play a role in LPS-mediated plasticity as they react to LPS and are implicated in facilitating recovery following SCI. However, it is unknown how microglia change in response to LPS following SCI to promote neuroplasticity. Here we used single-cell RNA sequencing to examine microglial responses in subacute and chronic SCI with and without an LPS injection. We show that subacute SCI is characterized by a disease-associated microglial (DAM) signature, while chronic SCI is highly heterogeneous, with both injury-induced and homeostatic states. With LPS injection, microglia shifted away from the homeostatic signature to a primed, translation-associated state and increased DAM in degenerated tracts caudal to the injury. Our results contribute to an understanding of how microglia and LPS-induced neuroinflammation contribute to plasticity following SCI.
Project description:Macrophage plasticity allows cells to adopt different phenotypes, a property with potentially important implications in chronic pulmonary disorders such as cystic fibrosis (CF). We examined the transcriptional and functional significance of macrophage repolarization from an “M1” (LPS-stimulated) towards an “M2” phenotype using 5 stimuli. We found that macrophages exhibit highly diverse responses to distinct M2-polarizing stimuli. Specifically, we observed that IL-10 abrogated LPS-tolerance allowing for rapid restoration of LPS responsiveness. In contrast, IL-4 enhanced LPS-tolerance, dampening pro-inflammatory responses after repeat LPS challenge. We found enrichment of phagocytosis-associated pathways in macrophages stimulated with IL-10, leading them to display the greatest efferocytosis ability. Finally, we observed that CF macrophages had intact reparative responses, suggesting that macrophage contributions to CF lung disease are shaped by their environmental milieu and are modifiable. These findings highlight the diversity of macrophage activation states, attribute functional consequences to these stimuli, and provide a unique resource of human macrophage repolarization markers.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.