Differential expression of the platelet-derived growth factor-A and -B genes during maturation of monocytes to macrophages.
1. Regulation of platelet-derived growth factor (PDGF)-A and -B gene expression was studied using resting monocytes, in vitro matured monocytes and alveolar macrophages. 2. Resting monocytes constitutively transcribed both PDGF-A and -B genes. When monocytes matured to macrophages in vitro, the transcription rates of both genes increased markedly. 3. Consistent with the transcription rates, resting monocytes constitutively expressed both PDGF-A and -B mRNAs. Interestingly, the PDGF-B mRNA levels increased markedly after the maturation, whereas the PDGF-A mRNA did not change. 4. Alveolar macrophages constitutively transcribed both PDGF-A and -B genes at almost the same rates. However, these cells contained 5-fold more PDGF-B mRNA than PDGF-A mRNA. 5. Immunohistochemical study using anti-PDGF-AA and anti-PDGF-BB antibodies suggested that PDGF-BB homodimers were more abundant than -AA homodimers or -AB heterodimers in alveolar macrophages and in vitro matured monocytes. 6. Together these observations indicate that in vitro matured monocytes and alveolar macrophages preferentially express PDGF-B mRNA and produce PDGF-BB homodimers, despite the equal transcription rates for both PDGF-A and -B genes.
Nagaoka
I
I
Department of Biochemistry, Juntendo University, School of Medicine, Tokyo, Japan.
Honma
S
S
Someya
A
A
Iwabuchi
K
K
Yamashita
T
T
D002454:Cell Differentiation; D015342:DNA Probes; D005786:Gene Expression Regulation; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D016676:Macrophages, Alveolar / Q000166:cytology / Q000378:metabolism; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D011487:Protein Conformation; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
D015342:DNA Probes; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger