Myocardial injection of CA promoter-based plasmid mediates efficient transgene expression in rat heart.
BACKGROUND
Although naked plasmid injection is the safest and most convenient method for gene delivery, a major limitation of this approach is currently poor transgene expression. The CA promoter (chicken beta-actin promoter with cytomegalovirus, CMV, enhancer) is one of the strongest transcriptional control modules found; however, it is uncertain whether a CA promoter-based vector is efficient enough for naked gene therapy in a cardiovascular context.


METHODS
The beta-galactosidase (LacZ) expression provided by CA promoter plasmid (pCAZ2) injection into the skeletal muscle or the heart of Lewis rats was compared with CMV promoter plasmid or adenoviral vector (AxCAZ3). The effect of Simian virus 40 of the replication origin (SV40ori) deletion from pCAZ2 on transgene expression was also evaluated.


RESULTS
pCAZ2 showed the highest LacZ expression in both skeletal muscle and heart in comparison with the CMV promoter-based vector 5 days after naked plasmid injection. LacZ expression in the heart obtained using 20 micro g of pCAZ2 was almost equivalent to that shown with AxCAZ3 at 6.0 x 10(9) optical particle units. The time course of transgene expression driven by CMV and CA promoters in the heart were similar, with the CA promoter providing significantly higher gene expression than the CMV promoter across all time points examined. SV40ori deletion from pCAZ2 did not affect transgene expression in either skeletal muscle or heart.


CONCLUSIONS
Transgene expression mediated by naked CA promoter-based plasmid injection was shown to be quite efficient in the heart. We propose that the CA promoter vector is suitable for myocardial gene therapy.
Huang
Jianhua
J
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Ito
Yoshinori
Y
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.|Division of Gene Therapy, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Kobune
Masayoshi
M
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.|4th Department of Internal Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Sasaki
Katsunori
K
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Nakamura
Kiminori
K
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Dehari
Hironari
H
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Takahashi
Kazuhiro
K
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.|Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Ikeda
Katsuya
K
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.|Department of Thoracic and Cardiovascular Surgery, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Uchida
Hiroaki
H
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Kato
Kazunori
K
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
Hamada
Hirofumi
H
Department of Molecular Medicine, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.|Division of Gene Therapy, Sapporo Medical University, South-1, West-17, Chuo-ku, Sapporo 0608556, Japan.
D000199:Actins / Q000235:genetics*; D000818:Animals; D003587:Cytomegalovirus / Q000235:genetics; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D007267:Injections; D007763:Lac Operon; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D051381:Rats; D011917:Rats, Inbred Lew; D019076:Transgenes; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D000199:Actins; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat