Transcriptional regulation of lung cytidylyltransferase in developing transgenic mice
Transcriptional regulation of lung cytidylyltransferase in developing transgenic mice
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DOI：
10.1165/rcmb.2005-0401oc
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发表时间：
2006-09-01
影响因子：
6.4
通讯作者：
Mallampalli, Rama K.
中科院分区：
文献类型：
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作者：
McCoy, Diann M.;Fisher, Kurt;Mallampalli, Rama K.
肺的发育与表面活性剂磷脂酰胆碱（PC）的大量产生有关，为新生儿进行宫外呼吸做好准备。这一过程与速率调节表面活性剂酶CTP：磷酸胆碱胞苷酰转移酶（CCT α）的活性显著增加有关。为了研究CCT α发育激活的分子基础，我们分析了内源性CCT α和报告基因β-半乳糖苷酶在胎儿、新生儿和成年启动子-报告基因转基因小鼠中的表达。含有类似于2 kb的CCT α启动子连接在β-半乳糖苷酶报告基因上游的转基因在远端肺上皮中显示出相对高的表达。内源性肺CCT α和β-半乳糖苷酶活性、蛋白质含量和转录水平在新生儿期内显示最大表达。在从转基因动物分离的培养的胎肺外植体中，CCTa和β-半乳糖苷酶活性和酶水平随着时间的推移而增加。在发育中的大鼠II型细胞中使用CCT α启动子-报告基因构建体的转染分析揭示，包含-169/+71的区域含有围产期激活所需的DNA元件。研究表明，表面活性剂磷脂的发育诱导至少部分是由于CCT α基因的转录激活。
Lung development is associated with a surge in surfactant phosphatidylcholine (PC) production to prepare the newborn for extrauterine breathing. This process is associated with a marked increase in the activity of the rate-regulatory surfactant enzyme, CTP:phosphocholine cyticlylyltransfe rase (CCT alpha). To investigate the molecular basis for developmental activation of CCT alpha, we analyzed expression of endogenous CCT alpha and a reporter gene, beta-galactosiclase, in fetal, newborn, and adult promoter-reporter transgenic mice. Transgenics harboring similar to 2 kb of the CCT alpha promoter linked upstream of a beta-galactosiclase reporter gene displayed relatively high expression in distal lung epithelia. Endogenous lung CCT alpha and beta-galactosidase activities, protein content, and transcript levels displayed maximal expression within the newborn period. CCTa and P-galactosidase activities and enzyme levels increased with time in cultured fetal lung explants isolated from transgenics. Transfectional analysis using CCT alpha pro moter-reporter constructs in developing rat type II cells revealed that a region encompassing -169/+71 contained the DNA elements required for perinatal activation. The studies demonstrate that developmental induction of surfactant phospholipid is due, at least in part, to transcriptional activation of the CCT alpha gene.