Retinoic acid-induced tissue transglutaminase and apoptosis in vascular smooth muscle cells.
Retinoids exert antiproliferative and prodifferentiating effects in vascular smooth muscle cells (SMCs) and reduce neointimal mass in balloon-injured blood vessels. The mechanisms through which retinoids carry out these effects are unknown but likely involve retinoid receptor-mediated changes in gene expression. Here we report the cloning, chromosomal mapping, and biological activity of the retinoid-response gene rat tissue transglutaminase (tTG). Northern blotting studies showed that tTG is rapidly and dose-dependently induced in a protein synthesis-independent manner after stimulation with the natural retinoid all-trans retinoic acid (atRA). The induction of tTG was selective for atRA and its stereoisomers 9-cis and 13-cis RA, because little or no elevation in mRNA expression was observed with a panel of growth factors. Western blotting and immunofluorescence confocal microscopy showed an accumulation of cytosolic tTG protein after atRA stimulation. Radiolabeled cross-linking studies revealed a corresponding elevation in in vitro tTG activity. The increase in tTG activity was reduced in the presence of 2 distinct inhibitors of tTG (monodansylcadaverine and cystamine). atRA-induced tTG mRNA and protein expression were followed by a significant elevation in SMC apoptosis. Such retinoid-induced programmed cell death could be partially inhibited with each tTG inhibitor and was completely blocked when both inhibitors were used simultaneously. These results establish a role for atRA in the sequential stimulation of tTG and apoptosis in cultured SMCs. atRA-mediated apoptosis in SMCs seems to require the participation of active tTG, suggesting a potential mechanistic link between this retinoid-inducible gene and programmed cell death.
Ou
H
H
Center for Cardiovascular Research, University of Rochester Medical Center, Rochester, NY, USA.
Haendeler
J
J
Aebly
M R
MR
Kelly
L A
LA
Cholewa
B C
BC
Koike
G
G
Kwitek-Black
A
A
Jacob
H J
HJ
Berk
B C
BC
Miano
J M
JM
D000818:Animals; D017209:Apoptosis; D015152:Blotting, Northern; D015153:Blotting, Western; D002103:Cadaverine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002478:Cells, Cultured; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003538:Cystamine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D006133:Growth Substances / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000187:drug effects; D011503:Transglutaminases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology
D004791:Enzyme Inhibitors; D006133:Growth Substances; D012333:RNA, Messenger; D014212:Tretinoin; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins; C008542:monodansylcadaverine; D002103:Cadaverine; D003538:Cystamine