Journal article
Chronic Pseudomonas aeruginosa infection reduces surfactant levels by inhibiting its biosynthesis
Cellular microbiology, Vol.9(4), pp.1062-1072
04/2007
DOI: 10.1111/j.1462-5822.2006.00852.x
PMID: 17166234
Abstract
Chronic Pseudomonas aeruginosa infection, as occurs in cystic fibrosis, is associated with decreased surfactant phospholipid levels. To investigate mechanisms, we measured synthesis of dipalmitoylphosphatidylcholine (DPPC), the major surfactant phospholipid. Mice received an agarose bead slurry alone, or were infected with beads containing a clinical mucoid isolate of P. aeruginosa. Bacterial infection after 3 days resulted in a approximately 50% reduction in surfactant DPPC content versus control. These changes in surfactant were associated with co-ordinate reductions in mRNAs and immunoreactive levels for CTP: phosphocholine cytidylyltransferase (CCTalpha), the rate-regulatory enzyme required for DPPC synthesis. P. aeruginosa infection of murine lung epithelia decreased CCTalpha gene transcription without altering mRNA stability and by a mechanism other than release of a soluble extracellular inhibitor. Promoter deletional analysis revealed that P. aeruginosa activates a negative response element from -1019 to -799 bp of the CCTalpha proximal 5'-flanking region. Exposure of cells to a P. aeruginosa mutant strain producing alginate reduced CCTalpha promoter activity, whereas these effects were not observed in strains defective in alginate synthesis. Murine type II cells isolated from P. aeruginosa-infected CCTalpha promoter-beta-galactosidase transgenic mice exhibited significantly reduced CCT and beta-galactosidase enzyme activities versus control. Thus, a mucoid P. aeruginosa strain reduces mRNA synthesis of a key biosynthetic enzyme thereby decreasing levels of surfactant.
Details
- Title: Subtitle
- Chronic Pseudomonas aeruginosa infection reduces surfactant levels by inhibiting its biosynthesis
- Creators
- Yanghong Wu - Department of Internal Medicine, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USAZhiwei XuFlorita C HendersonAlan J RyanTimothy L YahrRama K Mallampalli
- Resource Type
- Journal article
- Publication Details
- Cellular microbiology, Vol.9(4), pp.1062-1072
- Publisher
- England
- DOI
- 10.1111/j.1462-5822.2006.00852.x
- PMID
- 17166234
- ISSN
- 1462-5814
- eISSN
- 1462-5822
- Grant note
- R01 HL080229 / NHLBI NIH HHS T32 HL007344 / NHLBI NIH HHS R01 HL081784 / NHLBI NIH HHS T32 HL07734 / NHLBI NIH HHS R01 HL068135 / NHLBI NIH HHS
- Language
- English
- Date published
- 04/2007
- Academic Unit
- Microbiology and Immunology; Internal Medicine
- Record Identifier
- 9984001130402771
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