增生性瘢痕中凋亡相关基因转录的变化

Expression of apoptosis-related genes in proliferative and mature hypertrophic scars

目的 探讨凋亡相关基因bcl -2、bax、p5 3和c- myc在不同形成时期的增生性瘢痕中的基因转录变化。方法 提取 16例不同发生时期的增生性瘢痕和 8例正常皮肤的总RNA后 ,分离mRNA ,用逆转录 聚合酶链反应 (RT PCR)方法检测bcl- 2、bax、p5 3和c -myc基因在不同组织中的表达。结果 在增殖期的瘢痕中 ,凋亡促进基因bax、c- myc和 p5 3的表达量分别是正常皮肤的(62 .8± 14 .7) %、(78.0± 17.0 ) %和 (4 9.8± 4.3 ) % ,基因表达明显降低 (P <0 .0 5 ) ,而在成熟期的瘢痕中 ,这 3种基因的表达量都明显高于增殖期的瘢痕 ,恢复到正常皮肤水平。在正常皮肤中 ,bcl- 2基因表达水平较低 ,而在增殖期和成熟期的增生性瘢痕中表达量都显著升高 (P <0 .0 5 )。结论 bax、c- myc和 p5 3基因表达降低 ,bcl- 2基因表达增强可能是瘢痕中细胞凋亡减少 ,形成增生性瘢痕的机制之一 ,而bax、c- myc和 p5 3基因表达增强可能与瘢痕达到成熟状态有关。

Objective To investigate gene transcription of apoptosis-related genes,bcl-2,bax,p53 and C-myc in normal skin versus hypertrophic scars.Methods After total RNA in hypertrophic scars at different periods after wound and normal skin was isolated from 16 specimens of hypertrophic scars and 8 specimens of normal skin and was purified to mRNA,gene expression of bcl-2,bax,p53 and C-myc was detected by using reverse transcription-polymerase chain reaction (RT-PCR).Results In proliferative scars,the transcriptional levels of apoptosis-induced genes,bax,C-myc and p53,were significantly reduced as compared with that in normal skin (P<0.05),while in mature scars,the contents of these 3 gene transcripts were all significantly increased in comparison with proliferative scars and resumed to the levels of normal skin.In normal skin,the level of gene expression of bcl-2 was lower,while in hypertrophic scars,the level was significantly elevated (P<0.05).Conclusion The inhibition of gene expression of bax,p53 and C-myc and the activation of bcl-2 gene transcription in proliferative scars versus normal skin might lead to cellular apoptosis inhibition and hypertrophic scars formation,while the elevation of gene expression of bax,p53 and C-myc in mature scars versus proliferative scars might be associated with hypertrophic scars reaching mature stage.