Glucocorticoid enhances pulmonary surfactant protein B gene transcription.
Glucocorticoid enhances pulmonary surfactant protein B gene transcription.
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糖皮质激素增强肺表面活性蛋白 B 基因转录。
DOI：
10.1152/ajplung.1991.260.2.l37
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Whitsett,JA
中科院分区：
文献类型：
--
作者：
O'Reilly,MA;Clark,JC;Whitsett,JA
The effect of glucocorticoid on the regulation of pulmonary surfactant protein B (SP-B) synthesis was studied in a human pulmonary adenocarcinoma cell line. Northern blot analysis demonstrated a marked increase in SP-B mRNA expression after treatment with dexamethasone for 48 h. Actinomycin D, puromycin, or cycloheximide blocked the induction of SP-B mRNA by glucocorticoid. Nuclear run-on experiments demonstrated that the effects of dexamethasone on SP-B mRNA were due in part to increased transcription of the SP-B gene. However, during this time period, there was a discrepancy between SP-B gene transcription, which was increased only 2- to 4-fold, and SP-B mRNA, which increased 60- to 150-fold after treatment with dexamethasone. In the presence of actinomycin D, SP-B mRNA was relatively stable, decreasing slowly in the presence or absence of glucocorticoid. In contrast to the relative stability of SP-B mRNA in the presence of actinomycin D, SP-B mRNA was markedly decreased after exposure to puromycin, supporting the premise that continued protein synthesis, rather than transcription alone, is required for maintenance of SP-B mRNA levels. Induction of SP-B expression by glucocorticoids was dependent on enhanced SP-B gene transcription and was also dependent on continued protein synthesis. The discrepancy between the relative enhancement of SP-B transcription and SP-B mRNA suggests that posttranscriptional factors influence SP-B expression in this cell line.
