학술논문
Transcriptional regulation and structural organization of the human cytosolic phospholipase A(2) gene.
Document Type
Academic Journal
Author
Dolan-O'Keefe M; Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610, USA.; Chow V; Monnier J; Visner GA; Nick HS
Source
Publisher: American Physiological Society Country of Publication: United States NLM ID: 100901229 Publication Model: Print Cited Medium: Print ISSN: 1040-0605 (Print) Linking ISSN: 10400605 NLM ISO Abbreviation: Am J Physiol Lung Cell Mol Physiol Subsets: MEDLINE
Subject
Language
English
ISSN
1040-0605
Abstract
Cytokines are established regulators of the arachidonic acid cascade in lung cells. The levels of various arachidonic metabolites distinguish the normal and pathogenic states of the human lung. Arachidonyl-selective cytosolic phospholipase A(2) (cPLA(2)) is ubiquitously present in human lung and is most likely the rate-limiting step in eicosanoid generation. We therefore studied the regulation of this pivotal gene in human lung fibroblasts and epithelial cells by proinflammatory cytokines. We demonstrate a dose- and time-dependent induction of human cPLA(2) mRNA by interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma as well as the abrogation of this induction by glucocorticoids. Nuclear runoff studies demonstrate that de novo transcription of the cPLA(2) gene is required for cytokine induction. We have characterized the human cPLA(2) gene, which is encoded by 18 exons and spans in excess of 137 kb. Deletion analysis of a 3.4-kb fragment of the human promoter identified two regions responsible for basal expression of the cPLA(2) gene. Conversely, a CA-dinucleotide repeat in the proximal promoter appears to repress overall promoter activity. Understanding the molecular mechanisms associated with cytokine-dependent expression of the cPLA(2) gene should provide further insight into regulating the level of proinflammatory mediators in pulmonary diseases.