Gene trapping uncovers sex-specific mechanisms for upstream stimulatory factors 1 and 2 in angiotensinogen expression.
Gene trapping uncovers sex-specific mechanisms for upstream stimulatory factors 1 and 2 in angiotensinogen expression.
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DOI：
10.1161/hypertensionaha.112.192971
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发表时间：
2012-06
期刊：
影响因子：
--
通讯作者：
Sigmund CD
中科院分区：
文献类型：
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作者：
Park S;Liu X;Davis DR;Sigmund CD
位于人血管紧张素原（AGT）启动子-20位E盒内的单核苷酸多态性（C/A）可以通过转录因子上游刺激因子（USF）1和2的差异募集来调节转录激活。为了研究USF 1对AGT基因表达的贡献，将携带（− 20 C）人AGT转基因的小鼠与携带设计用于敲低USF 1表达的USF 1基因陷阱等位基因的小鼠交配。在双转基因小鼠的肝脏（9±1%）、生殖器周围脂肪（16±3%）、肾脏（17±1%）和大脑（34±2%）中，USF 1 mRNA相对于对照组减少。电泳迁移率变动试验证实了这种降低。染色质免疫沉淀（ChIP）分析显示USF 1减少，在雄性小鼠肝脏中的人AGT启动子处保留USF 2结合。人AGT表达在雌性小鼠的肝脏和其他组织中减少，但在雄性小鼠中没有。内源性AGT表达的减少不足以改变基线时的收缩压，但可导致喂食高脂饮食的雌性USF 1基因诱捕小鼠收缩压降低。静脉注射靶向USF 2的腺病毒shRNA治疗USF 1敲除的雄性动物导致USF 1、USF 2和人AGT蛋白的表达减少。我们从ChIP测定的数据表明，这种人AGT的减少是由于USF 2与人AGT启动子的结合减少。总之，USF 1和USF 2都是AGT转录调控所必需的，并且这些转录因子在体内的活性涉及不同的性别特异性和组织特异性机制。
A single-nucleotide polymorphism (C/A) located within an E-box at the −20 position of the human angiotensinogen (AGT) promoter may regulate transcriptional activation through differential recruitment of the transcription factors Upstream Stimulatory Factor (USF) 1 and 2. To study the contribution of USF1 on AGT gene expression, mice carrying a (−20C) human AGT transgene were bred with mice harboring a USF1 gene trap allele designed to knock down USF1 expression. USF1 mRNA was reduced relative to controls in liver (9±1%), perigenital adipose (16±3%), kidney (17±1%), and brain (34±2%) in double-transgenic mice. This decrease was confirmed by electrophoretic mobility shift assay. Chromatin immunoprecipitation (ChIP) analyses revealed a decrease in USF1, with retention of USF2 binding at the human AGT promoter in the liver of male mice. Human AGT expression was reduced in the liver and other tissues of female but not male mice. The decrease in endogenous AGT expression was insufficient to alter systolic blood pressure at baseline, but caused reduced systolic blood pressure in female USF1 gene trap mice fed a high fat diet. Treatment of USF1 knockdown males with intravenous adenoviral shRNA targeting USF2 resulted in reduced expression of USF1, USF2 and human AGT protein. Our data from ChIP assays suggests that this decrease in human AGT is due to decreased USF2 binding to the human AGT promoter. In conclusion, both USF1 and USF2 are essential for AGT transcriptional regulation, and distinct gender-specific and tissue-specific mechanisms are involved in the activities of these transcription factors in vivo.