Project description:This data set shows dramatic changes in gene expression in microglia isolated from C57Bl6/J mice subjected to transient middle cerebral artery occlusion, as compared to those subjected to sham surgery. Mice deficient in Mincle (Clec4e-/-) showed significantly improved injury outcomes 3 and 7 days after transient middle cerebral artery occlusion. However, when comparing changes in gene expression in microglia 24 hours after blood reperfusion, there were no differences between wild-type and Clec4e-/- mice, indicating that Mincle does not participate in early microglial activation. Wild type and Mincle knock-out (Clec4e-/-) mice. After 1 h of transient middle cerebral artery occlusion (tMCAO) and 24 h of reperfusion, mice were perfused with PBS, their brains dissected, and 2 ipsilesional hemispheres (with cerebellum and brainstem removed) pooled for microglia isolation. For sham-operated animals, the whole forebrain was used and brains were not pooled. After myelin separation by Percoll gradient centrifugation, around 80,000 CD45intermediate, CD11b+ microglial cells were sorted from each sample. Sham samples n=3, tMCAO samples n=5.
Project description:This data set shows dramatic changes in gene expression in microglia isolated from C57Bl6/J mice subjected to transient middle cerebral artery occlusion, as compared to those subjected to sham surgery. Mice deficient in Mincle (Clec4e-/-) showed significantly improved injury outcomes 3 and 7 days after transient middle cerebral artery occlusion. However, when comparing changes in gene expression in microglia 24 hours after blood reperfusion, there were no differences between wild-type and Clec4e-/- mice, indicating that Mincle does not participate in early microglial activation.
Project description:We inflicted TBI to chemokine-deficient mouse lines in order to establish involvement of various signalling pathways that may be addressed therapeutically. Interacting chemokine pathways in brain regulate distinct inflammatory cells. Activated microglia are separate from invading phagocytes and dendritic cells. Findings show potential targets to interfere with specific inflammatory responses after brain injury.
Project description:We inflicted TBI to chemokine-deficient mouse lines in order to establish involvement of various signalling pathways that may be addressed therapeutically. Interacting chemokine pathways in brain regulate distinct inflammatory cells. Activated microglia are separate from invading phagocytes and dendritic cells. Findings show potential targets to interfere with specific inflammatory responses after brain injury. TBI was carried out in Ccl3-/- and Ccr2-/- mice, total RNA prepared from injured cerebral neocortex after three days. RNA samples were from uninjured Ccl3-/- and Ccr2-/- mice as reference for hybridization on Affymetrix microarrays.
Project description:Engrams are considered to be substrates for memory storage, and the functional dysregulation of the engrams leads to cognition impairment.However, the cellular basis for these maladaptive changes lead to the forgetting of memories remains unclear. Here we found that the expression of autophagy protein 7 (Atg7) mRNA was dramatically upregulated in aged DG engrams, and led to the forgetting of contextual fear memory and the activation of surrounding microglia.To determine mechanism by which autophagy in DG engrams activates the surrounding microglia, mice were co-injected AAV-RAM-Cre either with AAV-Dio-Atg7-Flag or AAV-Dio- EYFP in dorsal dentate gyrus to overexpress ATG7 in the DG memory engrams. Microglia were separated using magnetic-activated cell sorting and subjected to RNA-Seq in dorsal hippocampus .Bioinformatics analysis shown overexpression of Atg7 in dorsal DG memory engrams caused an increase in the expression of Tlr2 in the surrounding microglia.Depletion of Toll-like receptor 2/4 (TLR2/4) in DG microglia prohibited excessive microglial activation and synapse elimination induced by the overexpression of ATG7 in DG engrams, and thus prevented forgetting. Furthermore, the expression of Rac1, a Rho-GTPases which regulates active forgetting in both fly and mice, was upregulated in aged engrams. Optogentic activation of Rac1 in DG engrams promoted the autophagy of the engrams, the activation of microglia, and the forgetting of fear memory. Invention of the Atg7 expression and microglia activation attenuated forgetting induced by activation of Rac1 in DG engrams. Together, our findings revealed autophagy-dependent synapse elimination of DG engrams by microglia as a novel forgetting mechanism.