CREG promotes a mature smooth muscle cell phenotype and reduces neointimal formation in balloon-injured rat carotid artery.
OBJECTIVE
We previously showed that cellular repressor of E1A-stimulated genes (CREG) is up-regulated during serum starvation-induced vascular smooth muscle cell (SMC) differentiation. The aim of this study was to determine the role of CREG in maintaining the quiescent, differentiated phenotype of SMCs both in culture and in balloon-injured rat carotid artery.


RESULTS
In cultured SMCs recombinant virus-mediated CREG expression enhanced cellular differentiation, inhibited proliferation, and reduced synthesis of extracellular matrix component fibronectin. In contrast, CREG knockdown via retroviral transfer of short hairpin RNAs abrogated serum starvation-induced SMC differentiation and growth arrest. Both immunostaining and Western analysis demonstrated marked down-regulation of CREG in the vascular media after balloon injury to the rat carotid artery. Retrovirus-mediated CREG transfer to the injured artery inhibited SMC dedifferentiation and proliferation, and reduced neointimal hyperplasia.


CONCLUSIONS
These results suggest that CREG participates in the maintenance of quiescent mature SMC phenotype in the arterial media by promoting SMC differentiation and growth arrest and that CREG gene transfer has therapeutic potential for vascular diseases associated with neointimal hyperplasia.
Han
Yaling
Y
Cardiovascular Research Institute and Department of Cardiology, Shenyang Northern Hospital, 83 Wenhua Road, Shenyang 110016, People's Republic of China. hanyaling@263.net
Deng
Jie
J
Guo
Liang
L
Yan
Chenghui
C
Liang
Ming
M
Kang
Jian
J
Liu
Haiwei
H
Graham
Alan M
AM
Li
Shaohua
S
D000818:Animals; D015153:Blotting, Western; D020212:Carotid Artery Injuries / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D002404:Catheterization / Q000009:adverse effects; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006965:Hyperplasia; D007150:Immunohistochemistry; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D010641:Phenotype; D034622:RNA Interference; D051381:Rats; D017207:Rats, Sprague-Dawley; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics; D013997:Time Factors; D017539:Tunica Intima / Q000378:metabolism* / Q000473:pathology
C114068:CREG1 protein, human; D016895:Culture Media, Serum-Free; D005353:Fibronectins; D012097:Repressor Proteins; D048049:Extracellular Signal-Regulated MAP Kinases