Fig. 4.
VIP inhibits nuclear translocation of the transcriptional regulator PU.1 in LPS-stimulated human THP1 monocytes. Cells were stimulated with E. coli LPS (100 ng/ml; a–c), E. coli LPS + VIP (10−8M; d–f) for 90 min. Images in the left column show localization of PU.1, images in centre column show transmitted light views, and images in the right column are overlaid images. Nuclear translocation of PU.1 is evident in THP1 cells stimulated with E. coli LPS (a–c) but is inhibited when cells are cocultured with E. coli LPS + VIP (d–f). Unstimulated monocytic THP1 cells (g) demonstrated a perinuclear localization of PU.1 (overlay image of anti-PU.1 FITC and transmitted light image). Cells stimulated with PMA (1 μg/ml) for 90 min (positive control cells) demonstrated PU.1 nuclear translocation (overlay image of anti-PU.1 FITC and transmitted light image; h). All results obtained are representative of results obtained on more than three separate occasions. Scale bar 10 μm. Closed arrows cell membrane, open arrows nuclear membrane. Data is representative of results obtained from five replicate experiments