FIGURE 6.

Chromatin remodeling in reactive astrocytes after cortical ischemic injury in vivo. (A) Brain sections from animals subjected to cortical devascularization were processed for immunofluorescence staining. To address changes in the global levels of H3K27ac in astrocytes in response to damage, we performed double immunofluorescence staining for GFAP and H3K27ac. Images show representative fields of the contralateral (CONTRA) hemisphere and the ipsilateral (IPSI) hemisphere with and without nuclear DAPI counterstaining. The arrowheads indicate representative astrocytes with visible nuclei. Here, GFAP intensity was enhanced using FIJI software to visualize cells, and intensity is not representative of the reactivity state. (B) Similar to A, we performed double immunofluorescence staining for GFAP and H3K9me3. (C) Graph showing the mean fluorescence intensity (MFI) for H3K27ac and H3K9me3 in the nuclei of GFAP-positive cells (black dots = astrocytes) or in other cell types nuclei (gray dots = total) after normalizing to the control (Ctrl = 1). (D) Graph showing the mean fluorescence intensity (MFI) for H3K27ac and H3K9me3 in the nuclei of GFAP-positive cells relative to the total nuclei and after normalizing to the control (Ctrl = 1). Average from the hemisphere of one animal was compared to the respective contralateral hemisphere (CONTRA) using one-sample t-test with the statistical significance represented as *p < 0.05, n = 4. (E) Schematic representation of a coronal section from a murine brain indicating the site of the cortical lesion (triangle dotted lines). The corpus callosum is shown in red and the hippocampal pyramidal cell layer and dentate gyrus are shown in black.