Wigle D A, Thompson K E, Yablonsky S, Zaidi S H, Coulber C, Jones P L, Rabinovitch M
Research Institute, The Hospital for Sick Children, and the Department of Pediatrics, University of Toronto, Ontario, Canada.
Circ Res. 1998 Aug 10;83(3):252-63. doi: 10.1161/01.res.83.3.252.
In previous studies, we showed that induction of pulmonary artery (PA) smooth muscle cell (SMC) elastase activity by serum-treated elastin (STE) requires DNA transcription. We therefore used differential mRNA display to identify transcripts expressed coincident with elastase induction. Twenty-four individual transcripts were differentially expressed from a screen of approximately 2000 mRNA sequences. An mRNA with sequence homology to the human transcription factor AML1 was identified and subsequently cloned from ovine PA SMCs. Since AML1 binds to a consensus sequence in the promoter of neutrophil elastase, we pursued the possibility that AML1 is a candidate transcription factor for SMC elastase. We documented by immunohistochemistry that serum stimulation induces increased expression of AML1 in the nucleus of PA SMCs. We also showed that STE induction of elastase activity is associated with early expression of AML1 mRNA and protein and that AML1 consensus sequence DNA binding activity is increased in nuclear extracts of STE-treated cells. In addition, AML1 antisense oligonucleotides reduced serum induction of elastase activity. Our study thus provides the first functional evidence of AML1 transcriptional activity related to elastase genes and offers novel insights into the broader biological significance of AML1 in nonmyeloid cells.
在先前的研究中，我们发现血清处理的弹性蛋白（STE）诱导肺动脉（PA）平滑肌细胞（SMC）弹性蛋白酶活性需要DNA转录。因此，我们使用差异mRNA显示技术来鉴定与弹性蛋白酶诱导同时表达的转录本。从大约2000个mRNA序列的筛选中，有24个个体转录本差异表达。鉴定出一个与人类转录因子AML1具有序列同源性的mRNA，随后从绵羊PA SMC中克隆出来。由于AML1与中性粒细胞弹性蛋白酶启动子中的共有序列结合，我们探讨了AML1是SMC弹性蛋白酶候选转录因子的可能性。我们通过免疫组织化学证明，血清刺激可诱导PA SMC细胞核中AML1表达增加。我们还表明，STE诱导弹性蛋白酶活性与AML1 mRNA和蛋白的早期表达相关，并且在STE处理细胞的核提取物中，AML1共有序列DNA结合活性增加。此外，AML1反义寡核苷酸降低了血清对弹性蛋白酶活性的诱导。因此，我们的研究提供了与弹性蛋白酶基因相关的AML1转录活性的首个功能证据，并为AML1在非髓样细胞中的更广泛生物学意义提供了新的见解。
