Effect of burn injury on the expression of cytokine genes in skin

Objective To study the effects of burn injury on the expression of cytokine genes.Methods Male ICR mice, 20～25 g, were anesthetized with intraperitoneal pentobarbital, which resulted in 20% Ⅲ degree burn injury. The unburned skin and serum were collected at 24 hours after the burn injury. Total RNAs were isolated from the skin. The expression of TNF-α, IL-1α and IL-6 genes were estimated by reversal transcription -polymerase chain reaction (RT-PCR). The level of TNF-α and IL-6 were also measured by ELISA.Results 20% Ⅲdegree burn injury could induce the expression of TNF-α and IL-6 genes in the unburned skin whereas the burn injury had no effects on the expression of IL-1α. The expression of TNF-α and IL-6 genes could not be detected in the skin of control animals. The burn injury increased the level of TNF-α in skin, but not in serum.The level of TNF-α in skin and serum was much lower in the control. Furthermore, the concentration of IL-6 was elevated both in the skin and in the serum after the burn. On the contrary, the level of IL-6 both in the skin and in the serum was low in the control group. There were significant differences between two groups (P0.01).Conclusion Burn injury might activate the skin immune system, and make the skin function as a cytokine-generating organ.