Tomita S, Tomita N, Yamada T, Zhang L, Kaneda Y, Morishita R, Ogihara T, Dzau V J, Horiuchi M
Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard University Medical School, Boston, MA, USA.
Circ Res. 1999 May 14;84(9):1059-66. doi: 10.1161/01.res.84.9.1059.
Renin is synthesized in high quantities in the juxtaglomerular cells of the kidney, but little or none is synthesized in the liver. Our previous in vitro and biochemical studies have demonstrated that tissue-specific expression of the mouse renin gene is regulated by the specific interaction between negative regulatory element (NRE) in the 5'-flanking region of the renin gene and NRE binding protein (NREB). In this study, we examined the hypothesis that this interaction between the NRE in the promoter region of the rat renin gene and the NREB in the liver contributes to the suppressed renin gene expression in this tissue in vivo. We used in vivo transfection of NRE transcription factor decoy (TFD) double-stranded oligonucleotide into the rat liver via portal vein infusion. A gel mobility shift assay showed that transfected NRE TFD blocked endogenous NREB binding with the rat renin gene. This resulted in enhanced hepatic renin mRNA expression, immunohistochemical detection of renin in the liver, and consequently, increased plasma renin concentration. Taken together, these results document the importance of NREB in the inhibition of renin gene expression in rat liver in vivo and suggest the possibility of in vivo renin gene modulation by the TFD approach.
肾素在肾脏的球旁细胞中大量合成，但在肝脏中很少或几乎不合成。我们之前的体外和生化研究表明，小鼠肾素基因的组织特异性表达受肾素基因5'侧翼区域的负调控元件（NRE）与NRE结合蛋白（NREB）之间的特异性相互作用调节。在本研究中，我们检验了以下假设：大鼠肾素基因启动子区域的NRE与肝脏中的NREB之间的这种相互作用导致该组织中肾素基因表达在体内受到抑制。我们通过门静脉输注将NRE转录因子诱饵（TFD）双链寡核苷酸体内转染到大鼠肝脏中。凝胶迁移率变动分析表明，转染的NRE TFD阻断了内源性NREB与大鼠肾素基因的结合。这导致肝脏中肾素mRNA表达增强，肝脏中肾素的免疫组化检测结果阳性，从而使血浆肾素浓度升高。综上所述，这些结果证明了NREB在体内抑制大鼠肝脏中肾素基因表达的重要性，并提示了通过TFD方法在体内调节肾素基因的可能性。
