Glucocorticoids suppress fibroblast apoptosis in an in vitro thermal injury model

The wounds of full- and deep partial-thickness burns result in hypertrophic scars and lead to skin contracture more severely than those of superficial partial-thickness burns. Therefore, preventing burn progression may help improve the aesthetic and functional outcomes after healing. Although a number of studies have focused on elucidating the underlying mechanisms of and preventing burn wound progression, it is still difficult to rescue burned dermis unless early tangential excision is performed. To investigate the underlying mechanisms of and prevent cell death of heat-injured fibroblasts, we developed an in vitro experimental model of heat-injured fibroblasts. We confirmed that heating at 55°C for 30s caused fibroblast necrosis immediately after heating, whereas heating at 46°C for 30s induced apoptosis 24h after heating. We also found that the supplementation of 100ng/ml betamethasone to the culture medium after heating decreased the number of apoptotic cells and increased that of live cells. Our studies suggest that glucocorticoids suppress apoptosis of heat-injured fibroblasts and may be useful for preventing burn wound progression.