Abstract

The regulation of burn serum on the TNF-α and high mobility group proteins 1 (HMGB1) secretion by macrophages was studied. Ten SD rats were conducted into the burn model to collect burn serum. RAW264.7 cells were treated with different concentration of burn serum and control serum (0, 0.5, 1.0, 1.5, 2.0 and 2.5 ml, respectively) for different time (0, 3, 6, 9, 12 and 24 h, respectively). After separated the serum, the levels of TNF-α and HMGB1 were measured by using enzyme-linked innmunosorbent assay (ELISA) double antibody sandwiched method. To observe the effects on secretion of TNF-α and HMGB1 in RAW264.7 cells after treated for 6 h with different concentration of burn serum, the results indicated that burn serum stimulation gradually increased the levels of TNF-α and HMGB1 in RAW264.7 cells. And the levels of TNF-α and HMGB1 obviously increased when treated with the burn serum by 1.5, 2.0 and 2.5 ml for 6 h, and it was significant difference when compared with the group of 0, 0.5 and 1.0 ml (P<0.05). In the group of 2.0 ml, the levels of TNF-α and HMGB1 increased over time. The levels of TNF-α began to increase at 6 h, and the secretion at 6, 9, 12 and 24 h was significant difference compared to 0 and 3 h (P<0.05). While the levels of HMGB1 began to increase at 9 h and the secretion at 9, 12 and 24 h was significant difference compared to 0, 3 and 6 h. But the levels of TNF-α and HMGB1 was no difference in treatment of different time and burn serum administration in normal group. Burn serum can reduce the release of TNF-α and HMGB1 in rat’s macrophages and show a significant dose-time-effect correlation.

Key words: Severe burn, tumor necrosis factor alpha (TNF-α), high mobility group proteins 1 (HMGB1), macrophages, secretion