title: Long-term and stable correction of uremic anemia by intramuscular injection of plasmids containing hypoxia-regulated system of erythropoietin expression.
abstract: Relative deficiency in production of glycoprotein hormone erythropoietin (Epo) is a major cause of renal anemia. This study planned to investigate whether the hypoxia-regulated system of Epo expression, constructed by fusing Epo gene to the chimeric phosphoglycerate kinase (PGK) hypoxia response elements (HRE) in combination with cytomegalovirus immediate- early (CMV IE) basal gene promoter and delivered by plasmid intramuscular injection, might provide a long-term physiologically regulated Epo secretion expression to correct the anemia in adenine-induced uremic rats. Plasmid vectors (pHRE-Epo) were synthesized by fusing human Epo cDNA to the HRE/CMV promoter. Hypoxia-inducible activity of this promoter was evaluated first in vitro and then in vivo in healthy and uremic rats (n = 30 per group). The vectors (pCMV-Epo) in which Epo expression was directed by a constitutive CMV gene promoter served as control. ANOVA and Student's t-test were used to analyze between- group differences. A high-level expression of Epo was induced by hypoxia in vitro and in vivo. Though both pHRE-Epo and pCMV-Epo corrected anemia, the hematocrit of the pCMV-Epo-treated rats exceeded the normal (P < 0.05), but that of the pHRE-Epo-treated rats didn't. Hypoxia-regulated system of Epo gene expression constructed by fusing Epo to the HRE/CMV promoter and delivered by plasmid intramuscular injection may provide a long-term and stable Epo expression and secretion in vivo to correct the anemia in adenine-induced uremic rats.
authors.affiliation: Department of Nephrology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China. jifeng-sun@medmail.com.cn
authors.forename: Jifeng
authors.initials: J
authors.lastname: Sun
authors.forename: Yarong
authors.initials: Y
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Dewei
authors.initials: D
authors.lastname: Du
authors.forename: Zhanting
authors.initials: Z
authors.lastname: Li
authors.forename: Junxia
authors.initials: J
authors.lastname: Wei
authors.forename: Angang
authors.initials: A
authors.lastname: Yang
mesh_terms: D000740:Anemia / Q000097:blood / Q000628:therapy*; D000818:Animals; D001483:Base Sequence; D001806:Blood Urea Nitrogen; D015687:Cell Hypoxia; D003404:Creatinine / Q000097:blood; D004921:Erythropoietin / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D007273:Injections, Intramuscular; D007668:Kidney / Q000473:pathology; D049409:Luciferases, Firefly / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D020218:Response Elements; D015533:Transcriptional Activation; D014511:Uremia / Q000097:blood / Q000628:therapy*
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin; D003404:Creatinine; D049409:Luciferases, Firefly