Fig. 8.

NO scavenging drives PAECs into mitosis and proliferation. A: PAEC cultures in 6-well plates were exposed to MCTP or c-PTIO for 5 days as indicated in Fig. 1 legend. After phase-contrast imaging, cultures were vigorously shaken horizontally and culture medium containing floating cells harvested. Cell harvests from two wells per variable were pooled, washed with fresh growth medium, and replated into fresh 6-well cultures. Replated cells were imaged one-day later by phase-contrast microscopy. Low-magnification fields are illustrated. Scale bar = 100 μm. B and C: STAT3 inhibitor indirubin E804 inhibits mitosis and Golgi dispersal due to NO scavenging. PAEC cultures in 6-well plates were exposed to c-PTIO for 48 h. In some cultures, indirubin E804 (5 μM) was included during the last 24 h. Phase-contrast images and giantin immunostaining show that indirubin inhibited entry of cells into mitosis (black arrowheads) and Golgi dispersal (white arrowheads). Quantitation of the fraction of cells with dispersed Golgi in all images collected from this experiment from respective cultures (mean % ± SE) is summarized in C. Scale bar = 50 μm in B. *P < 0.01.