Fig. 1

Increased BBB permeability at 5 weeks cuprizone is mediated by downregulation of tight junction proteins. a, b Quantitative RT-PCR analysis on dissected corpus callosum tissue samples from mice after 5 weeks cuprizone administration. Results show fold-change values of individual animals (N = 4) normalized to the mean of untreated control animals (set to 1; N = 4–8) according to color code. a Assessed were oligodendroglial genes (OL), astroglial and microglial markers (gliosis) and the endothelial markers. b Assessed were the inflammatory markers as indicated. c Representative electron micrographs of the neurovascular junction in control and cuprizone exposed animals. Arrowheads mark the separation between tight junctions of adjacent endothelial cells, and the asterisk points to split basement membranes (bm) (AC, astrocyte, EC, endothelial cell, Scale bar: 100 nm) (d-e) Representative pictures of the corpus callosum of untreated control mice and mice after 5 weeks cuprizone exposure immunostained for endothelial proteins as indicated (Scale bars: 20 μm). f Extravasation of the tracer FITC-dextran (70 kDa) in mice fed cuprizone for 5 weeks (arrowheads) but not in control mice. DiD vessel paint mark vessel outline (Scale bars: 50 μm). g Quantification of abundance of the tight junction proteins occludin (Ocln) and ZO1 from pictures as in (d) and (e) (N = 3 animals per group, Student’s t-test, P < 0.001). h Density of blood vessels (GLUT1 or PECAM1 positive vessels per 10,000 square μm) in the corpus callosum of control mice (N = 5) and mice after 5 weeks cuprizone (N = 4). Significance to control was evaluated by Student’s t-test (***P < 0.001). Total number of vessels per corpus callosum (vessels / CC) as evaluated by PECAM1 or GLUT1 staining is similar in both treatment groups (right panel)