Figure 3.

Histone H3 exacerbates disassembly of adherens junctions caused by inflammatory agents. A: HPAECs were stimulated with H3 or H4 (20 µg/mL) alone or in combination with LPS (100 ng/mL) or TNFα (5 ng/mL) for 6 h followed by immunofluorescence staining with VE-cadherin antibody. Actin stress fibers were visualized by staining with Texas Red phalloidin. Intercellular gaps are marked by arrows; bar = 10 µm. Images are representative of three independent experiments, 10–12 microscopic fields/condition. B: quantitative analysis of gap formation. Data represent means ± SD, n = 4, *P < 0.05. C: HPAECs were treated with HKSA (5 × 10⁸ particles/mL) alone or in combination with 20 µg/mL histone H3 followed by coimmunoprecipitation assays with VE-cadherin (left) or p120-catenin (right) antibodies. Western blot analysis of immunocomplexes was performed. Blots were reprobed with the antibodies used for immunoprecipitation as internal controls. Shown are representative blots of four independent experiments. Bar graph depicts quantitative densitometry analysis of Western blot data; *P < 0.05. HPAEC, human pulmonary artery endothelial cell; HKSA, heat-killed S. aureus; LPS, lipopolysaccharide; TNF-α, tumor necrosis factor-α.