Egr-1 in vascular smooth muscle cell proliferation in response to allo-antigen.
BACKGROUND
Early growth response factor-1 (Egr-1) plays an important role in regulating multiple factors involved in the progression of vascular lesions. This study examined our hypothesis that Egr-1 plays a critical role in the early stage of chronic cardiac allograft rejection and in the proliferation of the smooth muscle cell response to alloantigen.


METHODS
Antisense Egr-1 oligodeoxynucleotide (ODN) was ex vivo gene transfected into the donor hearts from DBA/2 mice, followed by heterotopic allografting into B10.D2 recipients. The allografts were harvested on day 30. Egr-1 and its target molecules, such as platelet-derived growth factor (PDGF)-A, basic fibroblastic growth factor (bFGF), vascular cell adhesion molecule (VCAM)-1, transforming growth factor (TGF)-beta and nonmuscle myosin heavy chain B (SMemb), were identified immunohistochemically, and the percentage of the lumen occluded by the intima was calculated. For the cell proliferation assay, sensitized T cells were harvested from B10.D2 recipients as stimulator and then added to the SMCs, which were harvested from DBA/2 mouse aorta. Cellular proliferation was measured and Egr-1 and its target gene expression were examined by real-time RT-PCR.


RESULTS
Egr-1 and its target genes were expressed in the thickened intima from untreated recipients. Egr-1 antisense ODN inhibited not only Egr-1 expression but also its target genes and significantly suppressed intimal thickening of coronary arteries. Egr-1 antisense ODN also significantly inhibited cell proliferation and expressions of Egr-1 and Egr-1 target genes in a mixed cell culture model.


CONCLUSIONS
We conclude that Egr-1 plays an important role in the formation of the cardiac allograft vasculopathy responding to alloantigens.
Wada
Yuko
Y
The Department of Surgery, Shinshu University School of Medicine, Matsumoto, Japan. aruko@hsp.md.shinshu-u.ac.jp
Fujimori
Minoru
M
Suzuki
Jun-ichi
J
Tsukioka
Katsuaki
K
Ito
Ken-ichi
K
Sawa
Yoshiki
Y
Morishita
Ryuichi
R
Kaneda
Yasufumi
Y
Isobe
Mitsuaki
M
Amano
Jun
J
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002908:Chronic Disease; D004268:DNA-Binding Proteins / Q000235:genetics*; D051766:Early Growth Response Protein 1; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D015316:Genetic Therapy; D006084:Graft Rejection / Q000276:immunology / Q000503:physiopathology / Q000628:therapy*; D016027:Heart Transplantation; D017874:Immediate-Early Proteins; D066298:In Vitro Techniques; D007519:Isoantigens / Q000502:physiology*; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D009131:Muscle, Smooth, Vascular / Q000473:pathology / Q000502:physiology*; D010710:Phosphates / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D005456:Fluorescent Dyes; D017874:Immediate-Early Proteins; D007519:Isoantigens; D010710:Phosphates; D012333:RNA, Messenger; D014157:Transcription Factors; C083120:phosphorodithioic acid; D016650:Fluorescein-5-isothiocyanate