title: Gene therapy with an erythropoietin enhancer-mediated, hypoxia-inducible gene expression system in the corpus cavernosum of mice with high-cholesterol diet-induced erectile dysfunction.
abstract: Cavernous hypoxia is an important factor in the pathogenesis of vasculogenic erectile dysfunction (ED). Therefore, the hypoxia-inducible gene expression system can be exploited as gene therapy for vasculogenic ED. This study was undertaken to examine the effectiveness of a hypoxia-inducible gene expression system, namely, the RTP801 promoter or the erythropoietin enhancer, in a mouse model of hypercholesterolemic ED in vivo and in primary cultured mouse cavernous endothelial cells in vitro. Two-month-old male C57BL/6 mice were fed a diet containing 4% cholesterol and 1% cholic acid, and age-matched control animals were fed a normal diet for 3 months. Mouse cavernous endothelial cells were isolated and cultured under normoxic or hypoxic conditions. After treatment of animals or endothelial cells with pSV-Luc, pRTP801-Luc, or pEpo-SV-Luc vector, gene expression was evaluated by luciferase assay, and the gene expression area was evaluated by immunohistochemistry. Plasmids pRTP801-Luc and pEpo-SV-Luc induced gene expression significantly in the hypercholesterolemic mice and in cavernous endothelial cells under hypoxia, and the highest gene expression was noted in the group treated with pEpo-SV-Luc. Gene expression was higher for more than 7 days in the hypercholesterolemic mice injected with pEpo-SV-Luc than in mice injected with pSV-Luc. As shown by immunohistochemistry, the gene expression area was also greater in the pEpo-SV-Luc group than in the pSV-Luc group, but the difference was not as great as that in luciferase activity. The hypoxia-specific gene expression system could be a valuable tool for facilitating gene delivery into ischemic corpus cavernosum tissue resulting from vascular causes.
authors.affiliation: Laboratory of Regenerative Sexual Medicine and Department of Urology, Inha University School of Medicine, 7-206, 3rd St, Shinheung-Dong, Jung-Gu, Incheon 400-711, Republic of Korea.
authors.forename: Ji-Kan
authors.initials: JK
authors.lastname: Ryu
authors.forename: Minhyung
authors.initials: M
authors.lastname: Lee
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Choi
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Kim
authors.forename: Hai-Rong
authors.initials: HR
authors.lastname: Jin
authors.forename: Woo Jean
authors.initials: WJ
authors.lastname: Kim
authors.forename: Guo Nan
authors.initials: GN
authors.lastname: Yin
authors.forename: Kang-Moon
authors.initials: KM
authors.lastname: Song
authors.forename: Mi-Hye
authors.initials: MH
authors.lastname: Kwon
authors.forename: Jun-Kyu
authors.initials: JK
authors.lastname: Suh
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001808:Blood Vessels / Q000378:metabolism; D015687:Cell Hypoxia / Q000235:genetics; D002478:Cells, Cultured; D002791:Cholesterol, Dietary; D004268:DNA-Binding Proteins / Q000235:genetics; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D004921:Erythropoietin / Q000235:genetics*; D017930:Genes, Reporter; D015316:Genetic Therapy; D006937:Hypercholesterolemia / Q000150:complications*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D018783:Impotence, Vasculogenic / Q000209:etiology / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010410:Penile Erection; D010413:Penis / Q000098:blood supply* / Q000503:physiopathology*; D011401:Promoter Regions, Genetic; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002791:Cholesterol, Dietary; D004268:DNA-Binding Proteins; C450979:Ddit4l protein, mouse; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014157:Transcription Factors; D004921:Erythropoietin