Fig. 3.

Senescent endothelial cells (ECs) demonstrate exacerbated permeability responses. Control and senescent ECs (at low and high population doublings, respectively) were utilized and cultured ex vivo. Senescence was evaluated by β-galactosidase (βgal) staining (A); quantitative measurement of βgal activity, fluorescence assay, normalized to total number of cells (B); expression of p16 by Western immunoblotting (C); and densitometric analyses (D). E–G: control (E) and senescent (F) ECs were challenged with LPS, and transendothelial electrical resistance (TER) was evaluated. G: bar graph represents peak differences in resistance of control and senescent ECs, normalized to respective untreated group. Values represent means ± SE; n = 3; **P < 0.01, ***P < 0.001 using Student’s 2-tailed t-test.