Effects of gender hormones on proliferation and apoptosis of IEC-6 cells after cutaneous burn

Objective To explore the effects of sex steroids on post-burn intestinal epithelial cells. Methods Sera from SD rats which received 30% total-body-surface full-thickness burn or sham treatment were used to treat confluent monolayer of IEC-6 cells. Diethylstilbestrol (DES), testosterone (T), or vehicle were then added. the effects on proliferation, cell-cycle distribution, apoptosis, cell number and Claudin-1 expression were investigated by means of MTT assays, flow cytometry, DAPI staining, RT-CES and fluorescent immunoassay, respectively. Results Serum from burned animals enhanced proliferation (0.777 vs 0.415, P<0.001), apoptosis (10.5% vs 1.59%, P<0.001) and Claudin-1 expression of IEC-6 cells, while reduced the cell number. Both DES and T inhibited proliferation and apoptosis of cells treated by scald serum. Specifically, proliferation index (12.3% vs 14.6%, P<0.001) and apoptotic rate (1.04% vs 2.33%, P<0.005) were lower in cells treated by DES than cells treated by T. Conclusions Post-burn intestinal epithelial barrier dysfunction is mainly due to surpass of apoptosis over proliferation. Both gender hormones inhibit proliferation and apoptosis in intestinal epithelial cells caused by cutaneous burn. In addition, estrogen had more obvious effects than androgen. Key words: Burn; Diethylstilbestrol; Testosterone; IEC-6 cell