[Expression of tumor necrosis factor related apoptosis inducing ligand and its receptor in thymus during early post-burn stage in rat with severe burns]

Abstract

Objective: To investigate the effect of tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its receptor on apoptosis in thymus during early post-burn stage in rat with severe burns.

Methods: Fifty Wistar rats were randomly divided into sham scald group (SS, n = 10) and burn group (n = 40). The apoptosis in thymus in rats was detected with annexin V/FITC-PI double staining at 4, 12, 24, 48 post-burn hours (PBH). The expression of TRAIL death receptor DR5, DR4 and its decoy receptor DcR1, DcR2 in thymus were detected by RT-PCR and Western blot at above time-points.

Results: Compared with that in SS group (6.7 +/- 0.8)%, the apoptosis in the thymus in burn group started to increase at 4 PBH [(17.1 +/- 0.4)%], peaked at 12 PBH [(25.2 +/- 1.1)%], and it was still evidently higher than that in SS group at 48 PBH (P < 0.05). There was no obvious difference in the apoptosis rate in rats in burn group among all the time-points. The expression of DR5 in burn group at each time-points was significantly higher than those in SS group, while that of DcR2 shown an opposite tendency (P < 0.05). The expression of DR4, DcR1 was similar in both groups.

Conclusion: The marked increase in apoptosis rate in rat thymus at early post-burn stage, and the significant change in the expression of DR5 and DcR2 show that TRAIL pathway may participate in apoptosis.