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目的探讨凋亡相关基因bax,bcl-2和p53在不同胎龄的胎儿皮肤和少儿皮肤组织中表达的变化特征及其可能的生物学意义。方法运用末端脱氧核糖转移酶介导的生物素化脱氧尿嘧啶缺口标记技术(TUNEL)检测18例不同胎龄(13-32周)的胎儿皮肤和6例少儿皮肤组织中细胞凋亡的变化后,提取这些皮肤组织中的总RNA,分离mRNA,用RT-PCR方法检测bax,bcl-2和p53基因在不同组织中的表达变化特征。结果随着胎儿的生长发育,皮肤组织中的细胞凋亡率逐渐增加。在早期妊娠胎儿的皮肤中,bcl-2基因表达水平较高,随着胎龄的增加,bcl-2基因的转录本含量逐渐降低,在少儿的皮肤组织中,这种基因的表达量明显低于早期妊娠胎儿皮肤(P<001)。与bcl-2基因不同,在早期妊娠胎儿皮肤组织中,p53基因表达水平较低,而在晚期妊娠胎儿和少儿的皮肤内,该基因表达较强,而bax基因在不同发育时期的胎儿和少儿皮肤组织中表达差异不显著(P>005)。结论晚期妊娠胎儿和少儿皮肤组织中细胞增殖减缓,细胞趋向分化或凋亡的增加可能与p53基因表达增强,bcl-2表达降低相关;而p53表达降低,bcl-2表达升高可能是早期妊娠胎儿皮肤中细胞凋亡较少的机制之一。
Objective To investigate the changes of apoptosis-related genes bax, bcl-2 and p53 expression in fetal skin and children’s skin tissues with different gestational ages and their possible biological significance. Methods TUNEL method was used to detect the changes of apoptosis in 18 cases of fetal skin and 6 cases of children’s skin tissue with different gestational age (13-32 weeks) by using TdT-mediated biotinylated deoxyuracil nicking (TUNEL) The total RNA was extracted from these skin tissues and mRNA was isolated. The expression changes of bax, bcl-2 and p53 genes in different tissues were detected by RT-PCR. Results As the fetus grew, the rate of apoptosis in skin tissue gradually increased. The expression of bcl-2 gene in fetal skin of early pregnancy is high, with the increase of gestational age, the content of bcl-2 gene transcript decreased gradually. In the skin of children, the expression of bcl-2 gene was significantly lower Fetal skin in early pregnancy (P <001). In contrast to the bcl-2 gene, p53 gene expression is low in fetal skin tissue of early pregnancy, whereas it is more abundant in the fetus and in the skin of children in late pregnancy, whereas the bax gene is expressed in fetuses and children at different developmental stages There was no significant difference in skin tissues (P> 005). Conclusions The cell proliferation, cell differentiation and apoptosis of fetus and children skin in late pregnancy may be related to the increase of p53 gene expression and the decrease of bcl-2 expression. The decrease of p53 expression and the increase of bcl-2 may be the result of early pregnancy One of the mechanisms of less apoptosis in fetal skin.