title: Comparison of cDNA and genomic forms of tyrosine hydroxylase gene therapy of the brain with Trojan horse liposomes.
abstract: BACKGROUND
  The present study examines whether chromosomal derived forms of therapeutic genes can be delivered to brain following intravenous administration. The brain expression of a rat tyrosine hydroxylase (TH) cDNA is compared to the brain expression of a plasmid DNA encoding the 18 kb rat TH gene.
  
  
  METHODS
  TH gene expression is measured in cell culture and in vivo in brain in experimental Parkinson's disease (PD). A total of four eukaryotic expression plasmids encoding rat TH were engineered wherein the size of the TH expression cassette ranged from 1.5 kb, in the case of the cDNA form of the gene, to 17.5 kb, in the case of the largest size genomic construct. The TH expression plasmids were delivered to either cultured cells or to rat brain in vivo with Trojan horse liposomes (THLs), which target the non-viral plasmid DNA to cells via cell membrane receptors.
  
  
  RESULTS
  The pattern of TH gene expression in cell culture and in vivo was similar: the cDNA form of the TH gene was fast-acting with short duration of action, and the genomic form of the TH gene was slow-acting with longer duration of action. The most sustained replacement of striatal TH enzyme activity in experimental PD was produced by combination gene therapy where both the cDNA and the genomic forms of the TH gene were administered simultaneously.
  
  
  CONCLUSIONS
  Eukaryotic expression plasmids encoding genomic forms of therapeutic genes, as large as 18 kb, can be successfully incorporated in THLs and delivered to brain following intravenous administration.
authors.affiliation: Department of Medicine, UCLA, Los Angeles, CA 90024, USA.
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Xia
authors.forename: Chun
authors.initials: C
authors.lastname: Chu
authors.forename: Jianyi
authors.initials: J
authors.lastname: Li
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ruben J
authors.initials: RJ
authors.lastname: Boado
authors.forename: William M
authors.initials: WM
authors.lastname: Pardridge
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology* / Q000378:metabolism; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000201:enzymology; D018076:DNA, Complementary / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D016678:Genome / Q000235:genetics*; D006801:Humans; D008081:Liposomes; D009457:Neuroglia / Q000201:enzymology; D010300:Parkinson Disease / Q000628:therapy*; D010957:Plasmids / Q000378:metabolism; D051381:Rats; D015183:Restriction Mapping; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D008081:Liposomes; D014446:Tyrosine 3-Monooxygenase