Surface Dilatational Behavior of Pulmonary Surfactant Components Spread on the Surface of a Pendant Drop. 2. Dipalmitoyl Phosphatidylcholine and Surfactant Protein B

Langmuir ◽  
2002 ◽  
Vol 18 (4) ◽  
pp. 1125-1130 ◽  
Author(s):  
R. Wüstneck ◽  
N. Wüstneck ◽  
B. Moser ◽  
U. Pison
Keyword(s):  
Pulmonary Surfactant ◽  
Surfactant Protein ◽  
Pendant Drop ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Surfactant Protein B ◽  
Protein B

Glucocorticoid enhances pulmonary surfactant protein B gene transcription

1991 ◽  
Vol 260 (2) ◽  
pp. L37-L43 ◽  
Author(s):  
M. A. O'Reilly ◽  
J. C. Clark ◽  
J. A. Whitsett
Keyword(s):  
Protein Synthesis ◽  
Cell Line ◽  
Gene Transcription ◽  
Pulmonary Surfactant ◽  
Actinomycin D ◽  
Surfactant Protein ◽  
Surfactant Protein B ◽  
Pulmonary Surfactant Protein B ◽  
Pulmonary Surfactant Protein ◽  
Protein B

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.

scholarly journals Pulmonary Surfactant Lipid Reorganization Induced by the Adsorption of the Oligomeric Surfactant Protein B Complex

2020 ◽  
Vol 432 (10) ◽  
pp. 3251-3268 ◽  
Author(s):  
Juho Liekkinen ◽  
Giray Enkavi ◽  
Matti Javanainen ◽  
Barbara Olmeda ◽  
Jesús Pérez-Gil ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Surfactant Protein ◽  
Surfactant Protein B ◽  
Surfactant Lipid ◽  
Protein B

scholarly journals Sequences of a hairpin structure in the 3′-untranslated region mediate regulation of human pulmonary surfactant protein B mRNA stability

2012 ◽  
Vol 302 (10) ◽  
pp. L1107-L1117 ◽  
Author(s):  
Helen W. Huang ◽  
David E. Payne ◽  
Weizhen Bi ◽  
Su Pan ◽  
Shirley R. Bruce ◽  
...  
Keyword(s):  
Mrna Stability ◽  
Hormonal Regulation ◽  
Untranslated Region ◽  
Pulmonary Surfactant ◽  
Specific Binding ◽  
Surfactant Protein ◽  
Hairpin Structure ◽  
Cytosolic Proteins ◽  
Surfactant Protein B ◽  
Protein B

The ability of pulmonary surfactant to reduce alveolar surface tension requires adequate expression of surfactant protein B (SP-B). Dexamethasone (DEX, 10−7 M) increases human SP-B mRNA stability by a mechanism that requires a 126-nt-long segment (the 7.6S region) of the 3′-untranslated region (3′-UTR). The objective of this study was to identify sequences in the 7.6S region that mediate regulation of SP-B mRNA stability. The 7.6S region was found to be sufficient for DEX-mediated stabilization of mRNA. Sequential substitution mutagenesis of the 7.6S region indicates that a 90-nt region is required for DEX-mediated stabilization and maintenance of intrinsic stability. In this region, one 30-nt-long element (002), predicted to form a stem-loop structure, is sufficient for DEX-mediated stabilization of mRNA and intrinsic mRNA stability. Cytosolic proteins specifically bind element 002, and binding activity is unaffected whether proteins are isolated from cells incubated in the absence or presence of DEX. While loop sequences of element 002 have no role in regulation of SP-B mRNA stability, the proximal stem sequences are required for DEX-mediated stabilization and specific binding of proteins. Mutation of the sequences that comprise the proximal or distal arm of the stem negates the destabilizing activity of element 002 on intrinsic SP-B mRNA stability. These results indicate that cytosolic proteins bind a single hairpin structure that mediates intrinsic and hormonal regulation of SP-B mRNA stability via mechanisms that involve sequences of the stems of the hairpin structure.

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