Hyperoxic stress elevates p52(PAI-1) mRNA abundance in cultured cells and adult rat pulmonary tissue.
Hyperoxic stress alters expression of genes involved in extracellular matrix (ECM) remodeling. To identify novel ECM-associated gene products positively regulated by hyperoxia, rat kidney cells were exposed to 95% O2, and the complement of [35S]methionine-labeled, saponin-resistant, ECM-associated proteins was compared with normoxic controls. O2-stressed cells accumulated significantly greater ECM levels (approximately 3- to 4-fold that of control cells) of a 52-kDa glycoprotein (p52), recently identified as the matrix form of plasminogen activator inhibitor type 1 (PAI-1) (P.J. Higgins, P. Chaudhari, and M.P. Ryan. Biochem. J. 273: 651-658, 1991; P. J. Higgins, M. P. Ryan, R. Zeheb, T. D. Gelehrter, P. Chaudhari. J. Cell. Physiol. 143:321-329, 1990), which peaked at 48 h of exposure. Hyperoxia-associated increases in ECM p52(PAI-1) content reflected parallel elevations in p52(PAI-1) mRNA abundance. Similar results were obtained using secondary cultures of rat pulmonary fibroblasts. This 48-h period of maximal hyperoxia-induced p52(PAI-1) expression in vitro was used to design subsequent in vivo studies. Adult rats were exposed to 99% O2 for 24-50 h, and RNA was extracted from the pulmonary tissue of stressed and control animals. A 5- to 8-fold and 6- to 15-fold increase in lung p52(PAI-1) mRNA content was evident in hyperoxia-treated rats at 24 and 50 h, respectively. All of this increase occurred in the defined 3.2-kb species of rat p52(PAI-1) mRNA. Actin mRNA levels increased three- to sevenfold as a function of hyperoxic stress, whereas catalase and glyceraldehyde-3-phosphate dehydrogenase mRNA abundance was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
White
J E
JE
Research Service, Samuel S. Stratton Department of Veterans Affairs Medical Center, Albany, New York.
Ryan
M P
MP
Tsan
M F
MF
Higgins
P J
PJ
D000818:Animals; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological / Q000235:genetics*
D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D010100:Oxygen