Buzzio Oscar L, Lu Zhenxiao, Miller Curt D, Unterman Terry G, Kim J Julie
Department of Obstetrics and Gynecology, Northwestern University, Chicago, Illinois 60611, USA.
Endocrinology. 2006 Aug;147(8):3870-6. doi: 10.1210/en.2006-0167. Epub 2006 May 11.
The forkhead box O1A (FOXO1A) has been identified as one gene that is up-regulated early in the decidualization process. To further investigate the role of FOXO1A during this process, six genes, IGFBP1, PRL, TIMP3, LAMB1, CNR1, and DCN, shown to be up-regulated during decidualization, were chosen as potential targets of FOXO1A action. Treatment of human endometrial stromal cells with hormones (estradiol and medroxyprogesterone acetate) plus dibutyryl cAMP (H+dbcAMP) for 48 h increased expression of IGFBP1, PRL, TIMP3, CNR1, and DCN but not LAMB1, as measured by real-time PCR. Silencing of FOXO1A using small interfering RNA oligonucleotides decreased IGFBP1 and DCN levels and increased CNR1, TIMP3, and PRL levels. LAMB1 was not affected. When FOXO1A was overexpressed in human endometrial stromal cells, expression of IGFBP1, DCN, and PRL increased, whereas levels of TIMP3 and CNR1 decreased. Addition of H+dbcAMP caused an increased expression of IGFBP1, PRL, and DCN beyond that of FOXO1A alone. TIMP3 and CNR1 levels decreased even further in response to H+dbcAMP compared with FOXO1A alone. LAMB1, which was unresponsive to FOXO1A, decreased when H+dbcAMP was added. Overexpressing FOXO1A also caused a change in cell shape, in that the stromal fibroblasts acquired a rounded, epithelioid appearance. Finally, reporter studies showed that cotransfection of FOXO1A significantly increased PRL promoter activity but not TIMP3 promoter activity. Addition of H+dbcAMP resulted in a significant increase in PRL promoter activity and a significant decrease in TIMP3 promoter activity. In summary, this study demonstrates the versatile nature of FOXO1A in the regulation of a number of decidualization-specific genes.
叉头框O1A（FOXO1A）已被确定为在蜕膜化过程早期上调的一个基因。为了进一步研究FOXO1A在此过程中的作用，选择了六个在蜕膜化过程中显示上调的基因，即胰岛素样生长因子结合蛋白1（IGFBP1）、催乳素（PRL）、金属蛋白酶组织抑制因子3（TIMP3）、层粘连蛋白β1（LAMB1）、大麻素受体1（CNR1）和双调蛋白聚糖（DCN），作为FOXO1A作用的潜在靶点。用激素（雌二醇和醋酸甲羟孕酮）加二丁酰环磷腺苷（H+dbcAMP）处理人子宫内膜基质细胞48小时，通过实时定量聚合酶链反应检测发现，IGFBP1、PRL.TIMP3、CNR1和DCN的表达增加，但LAMB1的表达未增加。使用小干扰RNA寡核苷酸沉默FOXO1A会降低IGFBP1和DCN水平，并增加CNR1、TIMP3和PRL水平。LAMB1不受影响。当FOXO1A在人子宫内膜基质细胞中过表达时，IGFBP1、DCN和PRL的表达增加，而TIMP3和CNR1的水平降低。添加H+dbcAMP导致IGFBP1、PRL和DCN的表达比单独的FOXO1A时增加。与单独的FOXO1A相比，TIMP3和CNR1水平在添加H+dbcAMP后进一步降低。对FOXO1A无反应的LAMB1在添加H+dbcAMP时降低。过表达FOXO1A还导致细胞形态发生变化，即基质成纤维细胞呈现圆形、上皮样外观。最后，报告基因研究表明，共转染FOXO1A可显著增加PRL启动子活性，但不增加TIMP3启动子活性。添加H+dbcAMP导致PRL启动子活性显著增加，TIMP3启动子活性显著降低。总之，本研究证明了FOXO1A在调节多个蜕膜化特异性基因方面具有多种作用。
