Figure 3. The FXR, a nuclear bile acid receptor, is detected in demyelinating lesions in PMS brains.

(A) Immunohistochemistry for PLP identified a WML in an MS brain. (B) Numerous FXR⁺ cells were detected within the lesion. (C) CD68 staining showed numerous CD68⁺ macrophages within the center of the lesion (red boxes from A and B), consistent with an active lesion. (D) Numerous FXR⁺ cells were detected within the center of the lesion, corresponding to the CD68⁺ macrophages. (E) Several CD68⁺ cells were also noted at the edge of the lesion (blue boxes from A and B). (F) Numerous FXR⁺ cells were also observed within the edge of the lesion shown in E. Scale bars: 500 μm (A and B); 100 μm (C–F).