Identification of three types of PDGF-A chain gene transcripts in rabbit vascular smooth muscle and their regulated expression during development and by angiotensin II.
PDGF-like peptides secreted from smooth muscles have been suggested to be responsible for the smooth muscle growth. In order to elucidate the nature of PDGF-like molecules expressed in vascular smooth muscles, we have isolated and characterized cDNA clones for PDGF-A chain from a rabbit embryonic aorta cDNA library. One of the cDNA clones was found to encode a novel PDGF-A chain, named PDGF-A3 in this report. PDGF-A3 arises from a single PDGF-A chain gene by alternative RNA splicing and differs from the sequences of previously reported endothelial- or the glioma-type transcripts by a 110 bp insertion. Expression of PDGF-A3 mRNA was selectively induced by Angiotensin II in the smooth muscle cell in vitro. Total PDGF-A mRNA is most enriched in embryonic aortas, but its expression is down-regulated with vascular development. PDGF-A mRNA is markedly increased in primary-cultured smooth muscle cells during the log-phase growth. Our results suggest that autocrine production of PDGF-A chains from the smooth muscle cell may play a role in early vascular development and in Angiotensin II-induced smooth muscle cell proliferation.
Nakahara
K
K
Department of Laboratory Medicine, University of Tokyo, Japan.
Nishimura
H
H
Kuro-o
M
M
Takewaki
S
S
Iwase
M
M
Ohkubo
A
A
Yazaki
Y
Y
Nagai
R
R
D000375:Aging; D000595:Amino Acid Sequence; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D001483:Base Sequence; D002455:Cell Division; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D015723:Gene Library; D005865:Gestational Age; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D024510:Muscle Development; D009131:Muscle, Smooth, Vascular / Q000196:embryology / Q000254:growth & development / Q000502:physiology*; D015345:Oligonucleotide Probes; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic / Q000187:drug effects
D046911:Macromolecular Substances; D015345:Oligonucleotide Probes; D010982:Platelet-Derived Growth Factor; D012333:RNA, Messenger; D000804:Angiotensin II