Journal: Fluids and Barriers of the CNS
Article Title: Blood-brain barrier permeability increases with the differentiation of glioblastoma cells in vitro
doi: 10.1186/s12987-024-00590-0
Figure Lengend Snippet: IL-6 modulates BBB permeability via STAT3 activation in blood-brain barrier cells. (a) Schematic representation of IL-6/STAT3 signalling. (b) hCMEC/D3 cells, grown for 7 days up to confluence in Transwell insert, were left untreated (CTRL) or incubated in the lower chamber with the conditioned medium derived from 5-day culture of GBM cells of patient #2, as medium from differentiated/adherent cells (AC), alone or containing an anti-IL-6 neutralizing antibody (Nab, 1/400), or medium from neurospheres (NS), alone or containing rhIL-6 (200 pg/mL). Immunoblot of STAT3 and phospho(Tyr705)STAT3. The expression of GAPDH was used as control of equal protein loading. The figure is representative of one out of three experiments with similar results. (c) BBB cells were grown as in b . When indicated the inhibitor of STAT3, STA-21 (30 µM) was co-incubated. Immunoblot of STAT3 and phospho(Tyr705)STAT3. The expression of GAPDH was used as control of equal protein loading. The figure is representative of one out of three experiments with similar results. (d) Immunoblotting of the indicated proteins in BBB cells, incubated as in c . The expression of GAPDH was used as control of equal protein loading. The figure is representative of one out of three experiments with similar results. ZO1: zonula occludens 1; CLDN3: claudin-3; CLDN5: claudin-5. (e) Permeability assay on BBB cells treated as in c . 5 µM doxorubicin, 10 µM mitoxantrone or 2 µM dextran 70-fluorescein isothiocyanate were added for 3 h. The compounds recovered from the lower chamber were measured fluorometrically, in duplicates. Data were presented as mean ± SD ( n = 3 independent experiments). * p < 0.05, *** p < 0.001: AC/NS vs. CTRL; ° p < 0.05, °° p < 0.01: STA-21-treated AC vs. AC, IL-6-treated NS vs. NS; # p < 0.05; STA-21 + IL-6 treated NS vs. IL-6 treated NS
Article Snippet: When indicated, the STAT3 inhibitor STA-21 (CAS 28882-53-3, Santa Cruz Biotechnology Inc., Santa Cruz, CA; 30 μM) or the proteolysis targeting chimera (PROTAC) against STAT3 SD-36 (#HY-129602, MedChemExpress, Monmouth Junction, NJ; 1 μM) were added in the Transwell insert containing hCMEC/D3 cells.
Techniques: Permeability, Activation Assay, Incubation, Derivative Assay, Western Blot, Expressing, Control