IDENTIFICATION OF UROKINASE AS A HYPEROXIA-INDUCIBLE GENE

Citation
Se. Juul et al., IDENTIFICATION OF UROKINASE AS A HYPEROXIA-INDUCIBLE GENE, MOLECULAR GENETICS AND METABOLISM, 63(4), 1998, pp. 295-301
Citations number
35
Categorie Soggetti
Genetics & Heredity","Medicine, Research & Experimental",Biology
ISSN journal
10967192
Volume
63
Issue
4
Year of publication
1998
Pages
295 - 301
Database
ISI
SICI code
1096-7192(1998)63:4<295:IOUAAH>2.0.ZU;2-P
Abstract
Hyperoxia has deleterious effects on lung form and function; however, the molecular events initiated by oxygen exposure remain unclear. We h ypothesized that macrophages function as important intermediaries in t he protective response of lung tissues after exposure to hyperoxia. Th is hypothesis was tested by exposing cultured macrophages (RAW 264.7 c ells) to hyperoxia for 24 h and then applying the conditioned medium f rom these cells to cultured pulmonary epithelial cells or to pulmonary microvascular endothelial cells. We observed that the expression of m anganese superoxide dismutase mRNA increased in both target cell lines , Therefore, we next hypothesized that exposure of these macrophages t o hyperoxia results in a change in gene expression which could be dete cted by differential display PCR (ddPCR), This hypothesis was tested b y exposing RAW 264.7 cells to greater than or equal to 95% oxygen (or normoxia) for 24 h, harvesting RNA, and performing ddPCR, A cDNA fragm ent upregulated by hyperoxia was identified and reamplified. Verificat ion of differential expression of mRNA was done by Northern analysis. A mRNA which was reproducibly upregulated by hyperoxia, as well as by lipopolysaccharide and interferon gamma, was identified. The different ially expressed PCR product was cloned and sequenced, revealing a prod uct with 99% identity to mouse urokinase mRNA We speculate that one fu nction of pulmonary macrophages following a hyperoxic exposure is to s ecrete urokinase. (C) 1998 Academic Press.