Figure 1. Effects of NaHS on cell viability and apoptosis in CSE-stimulated A549 cells. (A, B) A549 cells were treated with different doses of CSE or NaHS for 48h. The cells stimulated with vehicle only served as controls. Cell viability was detected by CCK-8 assay. *P<0.05, **P<0.01, significantly different from control cells. A549 cells were cultured with and without 3% CSE and/or 100, 200, or 400μM NaHS for 48 h. (C) Cell viability of A549 cells with different treatments was measured by CCK-8 assay. (D) A549 cells were stained with Hoechst 33258 after treating with and without 3% CSE and/or 400μM NaHS for 48 h, and were examined under the fluorescence microscopy. (E) The cells were double-stained with Annexin V-FITC and PI, and then the cellular apoptosis was determined by flow cytometry. (F) The ratio of apoptotic cells was statistically analyzed. (G, H) The protein levels of Bcl-2, Bax and Cleaved caspase 3 were detected using Western blot. **P<0.01, significantly different from control cells [3% CSE (-) and NaHS (-)]; #P<0.05, ##P<0.01, significantly different from cells treated with 3% CSE only.