Scott Roderick E M, Wu-Peng X S, Kaplitt Michael G, Pfaff Donald W
Neurobiology and Behavior, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Brain Res Mol Brain Res. 2003 Jun 10;114(2):91-100. doi: 10.1016/s0169-328x(03)00084-6.
The progesterone receptor (PR) gene is expressed in cells of the anterior pituitary and hypothalamus, and PR levels are regulated by estrogen (E) in a tissue-specific fashion. To demonstrate that E induces transcription via the PR promoter, and to identify sequences within the PR promoter responsible for tissue-specific and hormonal regulation, we have utilized a defective herpes simplex virus vector for direct gene transfer into the rat pituitary and brain. We designed a viral amplicon expressing the beta-galactosidase gene under the regulation of a 2.1-kb PR promoter fragment to create a defective viral vector for gene transfer into the brain. Following injection of this vector into the pituitary and brain, its pattern of expression and ability to respond to estradiol 3-benzoate (EB) were examined. In the pituitary, lacZ activity was observed in cells of the anterior lobe (AL). However, no activity was seen in the neurointermediate lobe (NIL), demonstrating tissue specific transcriptional regulation. A approximately sixfold increase in cells demonstrating beta-galactosidase activity was observed in the AL following treatment with EB. Likewise, injection of defective viral vector into the hypothalamus followed by treatment with EB resulted in a approximately eightfold increase in cells demonstrating beta-galactosidase activity including the very cell groups responsible for EB-dependent reproductive behavior. In contrast, no vector dependent activity was observed in the caudate nucleus, a tissue with no endogenous expression of PR, despite polymerase chain reaction evidence demonstrating the presence of the vector in this tissue. These results demonstrate that the 2.1-kb PR promoter fragment contains the sequence information required for correct tissue and hormonal regulation of PR.
孕激素受体（PR）基因在前脑垂体和下丘脑细胞中表达，并且PR水平以组织特异性方式受雌激素（E）调节。为了证明E通过PR启动子诱导转录，并确定PR启动子内负责组织特异性和激素调节的序列，我们利用了一种缺陷型单纯疱疹病毒载体将基因直接导入大鼠垂体和脑内。我们设计了一种病毒扩增子，其在2.1 kb PR启动子片段的调控下表达β-半乳糖苷酶基因，以创建一种用于基因导入脑内的缺陷型病毒载体。将该载体注入垂体和脑后，检测其表达模式以及对雌二醇3-苯甲酸酯（EB）的反应能力。在垂体中，在前叶（AL）细胞中观察到了lacZ活性。然而，在神经中间叶（NIL）中未观察到活性，这表明了组织特异性转录调控。用EB处理后，在AL中观察到显示β-半乳糖苷酶活性的细胞增加了约6倍。同样，将缺陷型病毒载体注入下丘脑，随后用EB处理，导致显示β-半乳糖苷酶活性的细胞增加了约8倍，其中包括负责EB依赖性生殖行为的细胞群。相比之下，尽管聚合酶链反应证据表明尾状核中存在该载体，但在尾状核中未观察到载体依赖性活性，尾状核是一种没有PR内源性表达的组织。这些结果表明，2.1 kb PR启动子片段包含PR正确的组织和激素调节所需的序列信息。
