Project description:This SuperSeries is composed of the following subset Series: GSE37611: Effect of small molecules on activated astrocytes GSE37612: Effect of small molecules on activated BV2 microglia cell line Refer to individual Series
Project description:We have developed an assay to test the neuroprotective properties of compounds using stem cellM-bM-^@M-^Sderived motor neurons and astrocytes, together with activated microglia as a stress paradigm. Hit compounds were discovered and the transcriptional response on activated astrocytes cells was tested. Neural stem cell (NSC)-derived astrocytes (AC) were activated with LPS and IFN-M-NM-3 and treated with hit compound for 4 hr.
Project description:Type I interferons (IFN-I) are crucial for effective antimicrobial defence in the central nervous system (CNS) but also can cause severe neurological disease (termed cerebral interferonopathy) as exemplified by Aicardi-Goutières Syndrome and chronic viral infection. In the CNS, microglia and astrocytes have essential roles in host responses to infection and injury, with both cell types responding to IFN-I. However, the extent to which the IFN-I responses of these cells differ, if at all, is still unknown. Here we determined the global transcriptional responses of astrocytes and microglia to the IFN-I, IFN-alpha. MGCs were prepared from 2–4 day-old C57BL/6 mice. Purified primary astrocytes were obtained from the MGCs by magnetic activated cell sorting using anti-CD11b beads. Microglia were obtained from mixed glial cell cultures by mechanical shaking for 4 h. After treating astrocytes and microglia with IFN-alpha for 12 h, microarray using Affymetrix mouse genome array 430 2.0 array was performed on total RNA extracted from these cells. We found that under basal conditions, each cell type has a unique gene expression pattern reflective of its developmental origin and biological function. Following stimulation with IFN-alpha for 12 h, astrocytes and microglia also displayed a common core response that was characterized by the increased expression of genes required for pathogen detection and elimination. Microglia had a more extensive and diverse response to IFN-alpha with twice the number of genes upregulated (282 vs. 141 genes) when compared with astrocytes. Validation of the findings in vivo further suggested that astrocytes and microglia play important but distinct roles in the development of IFN-alpha-driven cerebral interferonopathies.
Project description:Astrocytes, a major cell type found throughout the central nervous system have general roles in neuronal development, blood-brain barrier function, regulation of neuroimmune responses as well as metabolic support of other brain resident cells. Here we show that a distinct subtype of reactive astrocyte is induced by activated endothelial cells and is distinct from astrocytes classically activated by neuroinflammatory microglia. We show that activated endothelial cells strongly induce C3 + astrocytes that retain their phagocytic capacity while exhibiting a gain of neurotoxic function decreasing neuronal cell survival. We show that endothelial activated astrocytes have increased A1-astrocytic genes and exhibit a distinctive extracellular matrix remodeling profile. Finally, we show that endothelial activated astrocytes are Decorin positive and are associated to vascular amyloid deposits but not amyloid plaques in mouse models and AD/CAA patients. Taken together these findings show the existence of potentially extensive and subtle functional diversity of A1-reactive astrocytes. Astrocytes treated with Control or Activated Microglia or Endothelial Conditioned media
Project description:We have developed an assay to test the neuroprotective properties of compounds using stem cellM-bM-^@M-^Sderived motor neurons and astrocytes, together with activated microglia as a stress paradigm. Hit compounds were discovered and the transcriptional response on activated BV2 cells was tested. The BV2 cell line was activated with LPS and IFN-M-NM-3 and treated with hit compound for 4 hr.
Project description:We have developed an assay to test the neuroprotective properties of compounds using stem cell–derived motor neurons and astrocytes, together with activated microglia as a stress paradigm. Hit compounds were discovered and the transcriptional response on activated astrocytes cells was tested.
Project description:Isolation of glia from Alzheimer's mice reveals inflammation and dysfunction. Reactive astrocytes and microglia are associated with amyloid plaques in Alzheimer's disease (AD). Yet, not much is known about the molecular alterations underlying this reactive phenotype. To get an insight into the molecular changes underlying AD induced astrocyte and microglia reactivity, we performed a transcriptional analysis on acutely isolated astrocytes and microglia from the cortex of aged controls and APPswe/PS1dE9 AD mice. As expected, both cell types acquired a proinflammatory phenotype, which confirms the validity of our approach. Interestingly, we observed that the immune alteration in astrocytes was relatively more pronounced than in microglia. Concurrently, our data reveal that astrocytes display a reduced expression of neuronal support genes and genes involved in neuronal communication. The microglia showed a reduced expression of phagocytosis and/or endocytosis genes. Co-expression analysis of a human AD expression data set and the astrocyte and microglia data sets revealed that the inflammatory changes in astrocytes were remarkably comparable in mouse and human AD, whereas the microglia changes showed less similarity. Based on these findings we argue that chronically proinflammatory astrocyte and microglia phenotypes, showing a reduction of genes involved in neuronal support and neuronal signaling, are likely to contribute to the neuronal dysfunction and cognitive decline in AD. 2 cell types from 2 conditions: cortical microglia and cortical astrocytes from 15-18 month old APPswe/PS1dE9 mice compared to wildtype littermates. Biological replicates: microglia from APPswe/PS1dE9, N=7, microglia from WT, N=7, astrocytes from APPswe/PS1dE9, N=4, microglia from WT, N=4
Project description:Autoreactive T cells that infiltrate into the central nervous system (CNS) are believed to have a significant role in mediating the pathology of neurodegenerative diseases such as Alzheimer's disease, amyotrophic lateral sclerosis and multiple sclerosis. Their interaction with microglia and astrocytes in the CNS is crucial for the regulation of the neuroinflammatory process. Our previous work demonstrated that effectors secreted by Th1 and Th17 cells have different capacities to influence the phenotype and function of the glial cells. We have shown that Th1 effectors altered the phenotype and function of both microglia and astrocytes whereas Th17 effectors induced direct effects only on astrocytes but not on microglia. Here we investigated if effector molecules associated with IFN-g producing Th1 cells induced different gene expression profiles in microglia and astrocytes. We performed a microarray analysis of RNA isolated from microglia and astrocytes treated with medium and Th1 culture supernatants and compared the gene expression data. By using the criteria of 2-fold change and a false discovery rate of 0.01 (corrected p-value < 0.01), we demonstrated that a total of 2106 and 1594 genes were differentially regulated microglia and astrocytes respectively in response to Th1-derived factors. We observed that Th1 associated effectors induce distinct transcriptional changes in microglia and astrocytes in addition to commonly regulated transcripts. These distinct transcriptional changes regulate distinct physiological functions and this knowledge can help in better understanding of T cell mediated neuropathologies.