Expression of mast cell tryptase in scar / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the expression and distribution of mast cell tryptase (MCT) in scar, and to discuss the different MCT gene expression in keloid, hypertrophic scar and normal skin.</p><p><b>METHODS</b>20 samples of keloid, 20 samples of hypertrophic scar and 20 samples of normal skin were collected. The distribution of MCT was investigated by immunofluorescence histochemistry, and the MCT mRNA expression was detected by Relative Quantification real-time fluorescent PCR.</p><p><b>RESULTS</b>MCT gene was mainly located in the collagen fiber bundles of the scar, especially in the superficial layer of scar. MCT mRNA expression was significantly higher in keloid than that in hypertrophic scar and normal skin (P < 0.01). Averagely, the MCT gene expression in keloid was 2.5 times and 5.4 times of that in hypertrophic scar and normal skin.</p><p><b>CONCLUSIONS</b>MCT gene may play a role in the pathogenesis of scar.</p>

Expression of tumor necrosis factor related apoptosis inducing ligand and its receptor in thymus during early post-burn stage in rat with severe burns / 中华烧伤杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Expression and significance of TRAIL receptors in fibroblasts of hypertrophic scar / 中华整形外科杂志

<p><b>OBJECTIVE</b>To detect the expression of TRAIL receptors in fibroblasts of hypertrophic scar in the proliferative stage and explore its significance.</p><p><b>METHODS</b>30 samples of hypertrophic scar were taken from 30 burn cases in the proliferative stage. 30 samples of normal skin were taken as the control. The expressions of TRAIL receptors in the fibroblasts of hypertrophic burn scar and the normal skin were assayed by semiquantitative RT-PCR and flowcytometry.</p><p><b>RESULTS</b>The expression level of DR5 in the fibroblasts of hypertrophic burn scar is much lower than the control (P < 0.05); the expression level of DcR1 in the fibroblasts of hypertrophic burn scar is much higher than the control (P < 0.05).</p><p><b>CONCLUSIONS</b>The down-regulated DR5 expression and elevated DcR1 expressions in the fibroblasts of hypertrophic burn scar may attribute to the apoptosis change induced by TRAIL and explain the apoptosis differences between the fibroblasts of hypertrophic scar and normal skin to a certain extent.</p>