Project description:We generate whole-transcriptome RNA-seq profiles of microglia subpopulations in the adult zebrafish brain (4-month-old) to study their heterogeneity. Cells were isolated as ccl34b.1+mpeg1+ populations or ccl34b.1-mpeg1+ populations from the whole brain of double transgenic TgBAC(ccl34b.1:eGFP);Tg(mpeg1:DsRedx) fish. ccl34b.1+mpeg1+ and ccl34b.1-mpeg1+ microglia were grouped into two distinct clusters in the Principal component analysis (PCA), and we identified substantial differentially-expressed genes between these two microglial populations using the DESeq2 package. To further unveil their differential roles during inflammation, we injected E. coli into the brain ventricles of adult zebrafish and isolated both populations for whole-transcriptome RNA-seq. This RNA-seq profile provides valuable information for dissecting their respective functions in vivo.
Project description:Purpose: We purified whole brain microglia of MFP2 knockout mice and control mice utilizing percoll gradient and FACS sorting, followed by microarray analysis to define the molecular changes in MFP2 knockout mice at the endstage of the disease. We compared the microglia transcriptome of Mfp2-/- microglia to that of SOD1-G93A microglia isolated from spinal cord to define the microglia signature associated with a non-neurodegenerative environment. Results and conclusions: Mfp2-/- microglia acquire an activation state characterized by activation of mammalian target of rapamycin (mTOR). In addition, activated microglia display reduced expression of genes that are normally highly expressed by surveillant microglia in steady-state conditions. The immunological profile of is heterogeneous and encompasses upregulation of both pro- and anti-inflammatory genes. In contrast to the neurodegeneration-specific microglia profile in SOD1-G93A mice, Mfp2-/- microglia do not induce genes associated with phagocytosis, lysosomal activation and neurotoxicity. 4 MFP2 knockout and 4 control samples were subjected to microarray analysis.
Project description:The primary objective of this prospective observational study is to characterize the gut and oral microbiome as well as the whole blood transcriptome in gastrointestinal cancer patients and correlate these findings with cancer type, treatment efficacy and toxicity. Participants will be recruited from existing clinical sites only, no additional clinical sites are needed.
Project description:Preparation of primary microglial cultures from postnatal mice is tedious with a low yield, high variability and risk of astrocytic contamination. Microglia derived from embryonic stem cells (ESdM) have been suggested as alternative source, but it is unclear how closely ESdM resemble the molecular phenotype of primary microglia. Here, we performed a whole transcriptome analysis of ESdM in comparison to primary cultured and flow cytometry-sorted microglia and compared the microglial transcriptome to other cell types. Cultured microglia and ESdM were related to sorted microglia, but clearly distinct from other myeloid cell types, T cells, astrocytes and neurons. ESdM and primary cultured microglia showed strong overlap in their transcriptome. Only 144 gene transcripts were differentially expressed between both cell types, mainly derived from immune-related genes with a higher activation status of pro-inflammatory and immune defense genes in primary microglia compared to ESdM. Flow cytometry analysis of cell surface markers CD54, CD74 and CD274 selected from the microarray confirmed the close phenotypic relation between ESdM and primary cultured microglia. Thus, assessment of genome-wide transcriptional regulation demonstrates that microglia are distinct from other macrophage cell types and that mouse pluripotent stem cell-derived microglia are closely related to cultured postnatal microglia. Comparison of different primary neuronal cells with ES-cell derived microglial cells
Project description:Purpose: We purified spinal cord microglia utilizing percoll gradients and magnetic beads, followed by transcriptome profiling (RNA-seq) to define microglia expression profiles against other neural, immune cell-types. We next observed how the microglial transcriptomes change during activation in the SOD1-G93A mouse model of motor neuron degeneration at 3 time points. We also compared these profiles with that induced by LPS injection. Results and conclusions: ALS microglia were found to differ substantially from those activated by LPS and from M1/M2 macrophages by comparison with published datasets. These ALS microglia showing substantial induction of a neurodegeneration-tailored phenotype, with induction of lysosomal, RNA splicing, and Alzheimer's disease pathway genes. Overall they express a mixture of neuroprotective and neurotoxic factors during activation in ALS mice, showing that neuro-immune activation in the spinal cord is a double-edged sword. We also detected the transcriptional nature of surface marker expression in microglia (CD11b, CD86, CD11c), and substantial T-cell microglia cross-talk using correlative microglia transcriptome/FACS analysis. 42 total RNA samples from purified spinal cord microglia were subjected to paired-end RNA-sequencing. Parallel flow cytometry data was collected from the same spinal cords.
Project description:Purpose: Microglia are essential for central nervous system (CNS) homeostasis and innate neuroimmune function, and play important roles in neurodegeneration and brain aging. Here, we present gene expression profiles of purified microglia isolated at autopsy from the parietal cortex of 39 human subjects with intact cognition. We identified an age-associated gene signature in human microglia that was enriched for genes involved in cell adhesion, axonal guidance, cell surface receptor expression, and actin disassembly. Methods: mRNA profiles of 39 human microglia samples isolated from subjects with intact cognition, 16 corresponding superior parietal cortex tissue and 10 epilepsy surgical samples were generated in a Illumina HiSEQ 2500 sequencer. mRNA profiles of 6 parietal cortex from mice were prepared with a Quantseq 3’mRNA-Seq kit (Lexogen, USA). Reads were aligned to the hg38 assembly of the human genome using STAR and quantified at the gene level by featureCounts. Differential expression between whole brain tissue, surgical samples and isolated microglia was assessed with limma. Results: Overall, genes expressed by human microglia are similar to those in mouse, including established microglia genes CX3CR1, P2YR12, and ITGAM/CD11B. However, a number of immune genes, not identified as part of the mouse microglial signature, were abundantly expressed in human microglia, including TLR, Fc-gamma and SIGLEC receptors, as well as TAL1 and IFI16, regulators of proliferation and cell cycle. Age-associated changes in human microglia were enriched for genes involved in cell adhesion, axonal guidance, cell surface receptor expression, and actin (dis)assembly. Limited overlap was observed in microglial genes regulated during aging between mice and humans, indicating that human and mouse microglia age differently. Conclusions: Here we present the an extensive human microglia gene expression profile. Critical differences with mouse microglia, especially in the context of aging, were observed which highlight the necessity to independently study human microglia. These data and analyses serve as a starting point to address human-specific microglia genes and functions under physiological and neuropathological conditions.