Adenoviral-mediated delivery of early growth response factor-1 gene increases tissue perfusion in a murine model of hindlimb ischemia.
To test the hypothesis that overexpression of early growth response factor-1 (Egr-1) contributes to the revascularization of ischemic limbs, a constitutively active form of Egr-1 (Egr-1*) was made and evaluated in vitro and in vivo. Analyses of the transduced myocytes revealed significant upregulation of bFGF, PDGF-A, PDGF-B, IGF-II, and TGF-beta1. A coculture assay of the paracrine effects indicated that Ad-Egr-1* promoted proliferation and migration of endothelial cells. When Ad-Egr-1* was injected into the tibialis anterior muscle of mice, followed by explant culture in growth factor-reduced Matrigel, many capillary-like structures were observed in the Egr-1* group compared with minimal sprouting from the LacZ group, suggesting an angiogenic potential of Egr-1*. Next we evaluated Ad-Egr-1* in a murine model of hindlimb ischemia. Compared with slow revascularization in the control PBS or LacZ group, a rapid increase in tissue perfusion was observed in the Egr-1* group and the difference in flux ratio was statistically significant at day 7. In the injected muscle, expression of Egr-1*, upregulation of its target genes, and increased number of vessels staining positive for smooth muscle alpha-actin were observed. These results suggest that Egr-1 plays an important role in vascular recovery after occlusion and could be a potential target for therapeutic angiogenesis.
Lee
Young-Sam
YS
Department of Medicine, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Korea.
Jang
Hyung-Suk
HS
Kim
Jeong-Min
JM
Lee
Jung-Sun
JS
Lee
Jae-Young
JY
Li Kim
Koung
K
Shin
In-Soon
IS
Suh
Wonhee
W
Choi
Jin-Ho
JH
Jeon
Eun-Seok
ES
Byun
Jonghoe
J
Kim
Duk-Kyung
DK
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D051766:Early Growth Response Protein 1 / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*; D015316:Genetic Therapy; D005822:Genetic Vectors; D006614:Hindlimb / Q000098:blood supply*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007511:Ischemia / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000098:blood supply; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger