Expression of caveolin-3 in rat aortic vascular smooth muscle cells is determined by developmental state.
The presence of caveolin-3 was reinvestigated in smooth muscle cells in situ and in culture. Immunocytochemistry of aortic strips showed that both caveolins-1 and -3 are present, but that caveolin-3 is considerably less abundant and detected in only a fraction of the cells. Cultured smooth muscle cells of passage 4 or greater still expressed caveolin-1 but lacked caveolin-3, likely due to dedifferentiation. Cultures exposed to redifferentiation-inducing medium were found to re-express caveolin-3. The return of caveolin-3 protein in these cells was accompanied by a fourfold increase in cav-3 mRNA, as detected by quantitative PCR, suggesting that the loss of protein in untreated cells was due to transcriptional rather than translational inhibition. These results suggest that caveolin-3 has a specialized role associated with the differentiated state in certain types of smooth muscle cells.
Doyle
Donald D
DD
Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, Chicago, IL 60637, USA.
Upshaw-Earley
Judy
J
Bell
Eric
E
Palfrey
H Clive
HC
D000818:Animals; D001011:Aorta / Q000166:cytology*; D051244:Caveolin 3; D022461:Caveolins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D002454:Cell Differentiation; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation; D008856:Microscopy, Fluorescence; D009131:Muscle, Smooth, Vascular / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley
C495549:Cav3 protein, rat; D051244:Caveolin 3; D022461:Caveolins; D012333:RNA, Messenger