Hydrogen Sulfide Abrogates Hemoglobin-Lipid Interaction in Atherosclerotic Lesion

Figure 7

Endothelial responses provoked by Hb-lipid interactions are attenuated by sulfide donors. (a) OxLDL (200 μg/mL) was incubated with sulfide donors NaSH, GYY4137, AP67, and AP72 at the concentrations of 20 and 200 μmol/L at 37°C for 24 hours. Confluence HAoECs were exposed to the LDL samples for 4 hours then cell viability was determined by MTT assay. Representative experiment, , each performed in 8 wells in parallel. (b) OxLDL (200 μg/mL) was incubated with sulfide donors NaSH, GYY4137, AP67, and AP72 at the concentration of 20 and 200 μmol/L at 37°C for 24 hours. Confluence HAoECs were exposed to LDL samples (50 μg/mL) for 8 hours. HO-1 and HO-2 protein expressions were determined by Western blotting. Representative experiment, . (c–e) Hb (10 μmol/L) was incubated with H₂O₂ (50 μmol/L) in the presence or absence of sulfide donors NaSH, GYY4137, AP67, and AP72 (200 μmol/L) at 37°C for 90 minutes. (c) Confluence HAoECs were exposed to the obtained Hb samples for 8 hours and VCAM-1 expression was determined by Western blotting. Representative experiment, . (d, lower panel) Confluence HAoECs cultured in ECIS plates were exposed to the obtained Hb samples and transendothelial electrical resistance was monitored by ECIS instrument for 3 hours. Representative experiment, , each performed in triplicate (d, upper panel). HAoECs grown on coverslips, upon reaching confluence cells were exposed to the Hb samples for 8 hours. Cells were stained for F-actin (phalloidin-TRITC, red) and DNA (Hoechst, blue). White arrows show intercellular gaps. Representative image, . indicates statistical significance (). indicates statistical significance ().

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