血管活性肠肽、表皮生长因子上调支气管上皮细胞bcl-2基因表达

VASOACTIVE INTESTINAL PEPTIDE AND EPIDERMAL GROWTH FACTOR UPREGULATES bcl 2 GENE EXPRESSION IN BRONCHIAL EPITHELIAL CELLS *

为探索肺内调节肽血管活性肠肽（ＶＩＰ） 和表皮生长因子（ＥＧＦ） 抗氧化保护的基因机制， 用逆转录聚合酶链式反应（ＲＴＰＣＲ） 及Ｓｏｕｔｈｅｒｎ ｂｌｏｔ 杂交等方法检测原代培养的兔支气管上皮细胞（ＢＥＣ） 内ｂｃｌ２ 和ｃｍｙｃ 基因的表达情况， 观察ＶＩＰ、ＥＧＦ及热应激对这两个基因表达的影响。结果显示：（１） 基础情况下ＢＥＣ内有ｂｃｌ２ 和ｃｍｙｃ 基因的低水平表达；（２） ＥＧＦ和ＶＩＰ均明显增强ｂｃｌ２ 和ｃｍｙｃ 的转录，ＥＧＦ的作用更强， 而热应激无明显效应；（３） ｂｃｌ２ 和ｃｍｙｃ 两者的转录有显著相关性。上述结果提示，ＶＩＰ和ＥＧＦ等肺内调节肽可通过上调ｂｃｌ２ 基因表达增强支气管上皮细胞的抗氧化能力；ｃｍｙｃ 基因的编码产物可能是ｂｃｌ２ 基因转录的上游调节因子。

Expression of protooncogenes bcl 2 and c myc in cultured rabbit bronchial epithelial cell (BEC) was investigated in order to shed some light on genetic mechanisms underlying the protective antioxidant effect of pulmonary regulatory peptides, vasoactive intestinal peptide (VIP) and epidermal growth factor (EGF). Effects of these peptides and heat stress (HS) on expression of these genes were also studied. Total RNA was extracted from BEC. Bcl 2 mRNA and c myc mRNA were cloned with the method of RT PCR. GAPDH mRNA was used as internal control. The products of RT PCR were seperated with electrophoresis in 2% agarose gels. A computer image treating system (Stratagene eagleeyeⅡ) was used to identify the specific band and evaluate the density. The product bands of target genes bcl 2 were checked with Southern blot and oligoneucleotides probe hybridyzation. The results show: (1) a low level of bcl 2 and c myc gene transcription occur in BEC at the resting state; (2) both VIP and EGF could promote bcl 2 and c myc transcription, but no significant change could be found in the HS group; (3) there was a close correlation between bcl 2 and c myc transcription ( r =0 98, P <0 01). The above results indicate that VIP and EGF can improve the antioxidant effect of BEC by upregulating bcl 2 gene expression potently modulated by c myc protein.