OBJECTIVETo explore the molecular mechanism of apoptosis of the human umbilical vein endothelial cells (HUVECs) induced by burn serum and subeschar tissue fluid.

METHODSIn vitro cultured HUVECs were randomly divided into A (treated by normal serum, n = 6), B (treated by burn serum, n = 6) and C (treated by subeschar tissue fluid, n = 6) groups. The change in cellular nuclear morphology was determined by Hochst 33258 fluorescent staining, and the apoptotic rate was calculated at 24th and 36th post treatment hours (PTHs). The DNA ladder strips were observed with agarose electrophoresis at 12th and 24th PTH. The activity of caspase-3, 8, 9 was assayed by caspase colorimetric assay kit at 12 PTH.

RESULTSIt was found that nuclei appeared to be condensed and highly fluorescent granular in form in B and C groups. The nucleic apoptotic rate in B and C groups was (38.9 +/- 7.3)% and (49.5 +/- 6.5)%, respectively, which was evidently higher than that in A group (P < 0.01). The DNA ladder strips could be found by agarose electrophoresis in B and C groups. The activity of caspase-3, 8, 9 in B and C groups was significantly higher than that in A group after 12 PTHs (P < 0.01).

CONCLUSIONBurn serum and subeschar tissue fluid might induce apoptosis of HUVEC by means of the activation of death receptor and mitochondrial signal pathways simultaneously.