Figure 5

Effect of MPs on HUVEC barrier function. (A) TNF is a paradigmatic stimulus that induces significant and progressive reduction of TEER (normalized TEER) (B, C) Normalized TEER of confluent HUVECs left untreated (Medium) or exposed to MPs at the indicated concentrations. MPs from one healthy control (Control 3) and one RRMS patient (RR 3) were compared in a (B) and MPs from one CIS patient and from a RRMS patient (RR 2) were compared in (C). ( D ) Percentage of TEER decrease induced after 14 hours of incubation with Control, CIS and RR-MPs at 250, 500 and 1000 MP/μl (see Methods). Average TEER decrease in response to TNF is marked by discontinuous lines. **p = 0.004. (E) HUVECs left untreated (Medium) of previously treated for 14 h with MPs from a healthy control and a RRMS (RR) patient at 1000 MP/μl were stained for the cell-cell junction markers VE-cadherin and ZO-1 and for filamentous actin (F-actin). Semi-automated image processing identified intercellular gaps in the images (mask) that were quantified respect to the total area of the cell monolayer (right graph). *p = 0.01. Bar, 20 μm.