烫伤延迟复苏后小肠PPL凋亡率及凋亡相关基因表达的变化

Changes of apoptosis rate and expression of apoptosis -related gene of PPL after burn and delayed resuscitation

目的 :探讨烫伤延迟复苏对小肠Peyer氏结节淋巴细胞 (PPL)凋亡率 (ap % )及凋亡相关基因表达的影响。方法 :Wistar大鼠 30只 ,分为立即复苏 (ER)和延迟复苏 (DR)。 30 % Щ度烫伤模型 ,采用DNA片段百分率、DNA电泳及RT -PCR观察伤后PPLap %变化及ICE、bcl- 2及TNFα、IL - 2mRNA表达变化。结果 :烫伤后 6h ,PPLap %显著上升 (P <0 .0 1 ) ,DR组显著高于ER组 (P <0 .0 5～ 0 .0 1 )。电泳可见明确梯形条带 ;ICE伤后 6h、1 2h ,DR组显著高于ER组。Bcl- 2伤前强表达 ,伤后 6hDR组显著低于ER组 ;两组伤后 1 2hTNFα表达均显著高于伤前。两组IL - 2伤前呈强表达 ,伤后 6h表达减弱 ;DR组显著低于ER组 (P <0 .0 1 )。结论 :烫伤延迟复苏后促凋亡和抑凋亡基因表达失衡 。

Objectives: To study the effects of burn and delayed resuscitation on the apoptosis percentage (ap%) of intestinal Peyer's patch lymphocyte (PPL) and the expression of apoptosis-related genes in rats. Methods:Thirty Wistar rats were divided into early resuscitation(ER) and delayed resuscitation(DR) groups,24 rats were subjected to 30% TBSA III degree scald burn,6 sham rats were served as control. DNA fragmentation, DNA agarose gel electrophoresis were used to observe the changes of ap% ; RT-PCR was applied to exam the mRNA expression of interleukin-1β-converting enzyme (ICE), B-cell lymphoma/leukemia-2 (bcl-2), TNFα and IL-2 postburn. Results: The ap% of PPL increased significantly at 6 h postburn (PB), distinct DNA ladders were discerned in agarose gel electrophoresis. The expression of ICE increased dramatically postburn, and it expressed higher in DR group than in ER group . The expression of bcl-2 was strong in PPL before burn and became weak and weak postburn. The TNFα gene showed a stronger expression and was enhanced by delayed resuscitation. The expression of IL-2 showed a trend of descending; and there was a significant difference at 12 h postburn between the two groups. Conclusion: The imbalance expression of apoptosis-enhanced gene and apoptosis-inhibited gene after burn and delayed resuscitation might be responsible for the dramatically increased apoptosis in PPL.