[Effect of C8-ceramide on apoptosis of alveolar type II epithelial cells]

To investigate the effects of exogenous C8-ceramide on primary alveolar type II epithelial cells (AECII).

AECII were isolated from 18 day gestational age ICR mice, and cultured in Dulbecco's Modified Eagle Medium with 95% air and 5% CO₂at 37 °C. The cells were treated with different concentrations (0, 20, 40 and 80 µmol/L) of C8-ceramide for 24 h and treated with 80 µmol/L of C8-ceramide for different time (3, 6, 12, and 24 h) to observe the viability of cells by MTT assay. Then, the annexin V externalization assay and TUNEL assay were performed to determine apoptosis after the cells were treated with different concentrations (0, 20, 40, and 80 µmol/L) of C8-ceramide for different time (12 and 24 h).

The results of MTT assay showed that cell viability decreased in a dose- and time- dependent manner. In Annexin V externalization assay, the cells showed a distribution of (20.63 ± 0.86)%, (22.67 ± 1.72)%, (42.03 ± 1.34)%, (50.40 ± 1.30)% and (20.93 ± 2.51)%, (28.93 ± 3.19)%, (47.00 ± 1.08)%, (57.77 ± 3.04)% cells in apoptosis after treated with 0, 20, 40, 80 µmol/L of C8-ceramide for 12 and 24 h (It is significant difference from untreated cells except for 20 µmol/L at 12 h point, all P<0.05). In TUNEL assay, the cells showed a distribution of (5.51 ± 1.41)%, (13.24 ± 2.62)%, (35.10 ± 4.59)%, (75.07 ± 4.37)% and (5.56 ± 1.36)%, (21.34 ± 2.09)%, (37.12 ± 2.11)%, (91.33 ± 0.72)% cells in apoptosis after treated with 0, 20, 40, 80 µmol/L of C8-ceramide for 12 and 24 h (It is significant difference from untreated cells at the same time point, all P<0.05).

The results demonstrate that C8-ceramide can decrease the viability of AECII and induce apoptosis.