Figure 4

EPOR detection using ctEPOR-AB in healthy and injured mouse brain by immunohistochemistry: (A) EpoR staining in a subpopulation of CC-1 positive mature oligodendrocytes in the neocortex of a 5-wk-old healthy mouse. (B, B′, B″) EpoR staining in the hippocampus of a 5-wk-old NG2-CreERT2:R26-td-tomato-mEGFP mouse. Some oligodendrocyte precursor cells (arrow head) and newly differentiated oligodendrocytes (arrow) express EpoR. Both cell types are endogenously labeled with membrane-tagged EGFP. (C) EpoR staining of GFAP+ cellular processes in the dentate gyrus of a 5-wk-old mouse (arrow heads). (D) Overview of the injection site in the motor cortex of an 8-wk-old mouse injected with medium only (stab wound analogue). The section was stained for neuronal nuclei with NeuN and for EpoR with ctEPOR-AB. (E) Close-up of the white-rectangle region in (D) shows reactive cells with upregulated EpoR expression. (F) Many of the cells at the injection site with upregulated EpoR expression are GFAP+ (arrow heads). (G) Contralateral to the injection site, GFAP+ cells show no EpoR expression at 24 h after lesion. (H, H′, H″) Shown is EPOR and HA double-labeling of injected EOC-20 microglial cells transduced with an HA-tagged human EPOR. In addition, HA-negative cells at the injection site show strong EpoR expression (arrow heads).