H₂S induces reorganization of the actin cytoskeleton in HUVECs.

(A) The effects of H₂S on the actin cytoskeleton and on paxillin-containing focal adhesions. Serum-starved HUVECs were stimulated or not by 50 µM NaHS for indicated times. Thereafter, immunofluorescence analysis was performed using DAPI (blue) to stain nucleus, rhodamine-conjugated phalloidin (red) to stain F-actin and a mouse anti-paxillin monoclonal antibody followed by Alexa Fluor-labeled secondary antibody (green) to stain paxillin-contained focal adhesions. An overlay of fluorescent signals, generating yellow color in areas of colocalization, is shown on the right column. The thin arrows indicate lamellipodia, arrowheads indicate cell protrusions and thick arrows show paxillin-containing focal adhesions. Scale bars, 10 µm. Representative blots (B) and statistical values (C) showing that NaHS (50 µM) treatment has no effect on the phosphorylation of paxillin. The results are representative of three independent experiments. Values are means ± SE. NS, not significant.