Figure 3.

TGF-β treatment of HBVP reduced the amount and complexity of TJ in endothelial cells. (A) TGF-β1 plus -β2 (each 10 ng/mL) were added into the bottom chamber of wells containing intact BBB layers. Twenty-four hours later, PBMVEC growing on the upper part of the membrane were collected and prepared for freeze fraction electron microscopy. Red stars exemplarily indicate TJ branches. Exemplarily, one photograph is shown. (B) TJs were manually labeled in different visual fields (n = 2, in total 4 replicates). (C,D) Quantification of TJs density (C) and complexity (D). Black bar and circles present controls, grey bars and squares present the TGF-β treatment (n = 6 visual fields for controls, n = 8 for TGF-β; **** p < 0.0001).