Platelet-derived growth factor and growth-related genes in rat lung. II. Effect of exposure to 85% O2.
The expression of platelet-derived growth factor (PDGF), its receptor, and related genes was studied in the lung tissue of rats exposed to air or 85% O2. PDGF-B chain mRNA was increased by 6 days and PDGF B-type receptor mRNA was increased by 4 and 6 days of exposure to 85% O2. Despite a continued increase of cell division, both PDGF-B chain and B-type receptor mRNAs had returned to control values by 14 days of exposure to 85% O2. PDGF-A chain mRNA was unaffected by exposure to 85% O2. Nuclear runoff transcription analysis confirmed increased transcription of PDGF-B chain mRNA, whereas Western blot analysis of lung homogenates suggested consequent increased translation of PDGF-B chain mRNA to PDGF-BB at 7 days of exposure to 85% O2. Combined immunocytochemistry and autoradiography localized PDGF-BB to the major site of cell division, the pulmonary interstitium. We speculate that the early pulmonary fibroblast hyperplasia observed following exposure to 85% O2 is mediated by increased PDGF-B chain gene expression and may also be mediated by changes in PDGF B-type receptor gene expression.
Han
R N
RN
Department of Paediatrics, Hospital for Sick Children Research Institute, Toronto, Ontario, Canada.
Buch
S
S
Freeman
B A
BA
Post
M
M
Tanswell
A K
AK
D000818:Animals; D001345:Autoradiography; D005260:Female; D005796:Genes; D007150:Immunohistochemistry; D008168:Lung / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D010100:Oxygen / Q000494:pharmacology*; D010982:Platelet-Derived Growth Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism; D017479:Receptors, Platelet-Derived Growth Factor; D013936:Thymidine / Q000493:pharmacokinetics
D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017479:Receptors, Platelet-Derived Growth Factor; D010100:Oxygen; D013936:Thymidine