Gene electro-transfer of an improved erythropoietin plasmid in mice and non-human primates.
BACKGROUND
Anemia due to impaired erythropoietin (EPO) production is associated with kidney failure. Recombinant proteins are commonly administered to alleviate the symptoms of this dysfunction, whereas gene therapy approaches envisaging the delivery of EPO genes have been tried in animal models in order to achieve stable and long-lasting EPO protein production. Naked DNA intramuscular injection is a safe approach for gene delivery; however, transduction levels show high inter-individual variability in rodents and very poor efficiency in non-human primates. Transduction can be improved in several animal models by application of electric pulses after DNA injection.


METHODS
We have designed a modified EPO gene version by changing the EPO leader sequence and optimizing the gene codon usage. This modified gene was electro-injected into mice, rabbits and cynomolgus monkeys to test for protein production and biological effect.


CONCLUSIONS
The modified EPO gene yields higher levels of circulating transgene product and a more significant biological effect than the wild-type gene in all the species tested, thus showing great potential in clinically developable gene therapy approaches for EPO delivery.
Fattori
Elena
E
Istituto di Ricerche di Biologia Molecolare (IRBM), Via Pontina Km 30.600, 00040 Pomezia (Rome), Italy. Elena_Fattori@merck.com
Cappelletti
Manuela
M
Zampaglione
Immacolata
I
Mennuni
Carmela
C
Calvaruso
Francesco
F
Arcuri
Mirko
M
Rizzuto
Gabriella
G
Costa
Patrizia
P
Perretta
Gemma
G
Ciliberto
Gennaro
G
La Monica
Nicola
N
D000818:Animals; D015152:Blotting, Northern; D003062:Codon / Q000235:genetics; D018274:Electroporation / Q000295:instrumentation / Q000379:methods*; D004921:Erythropoietin / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006400:Hematocrit; D008252:Macaca fascicularis; D051379:Mice; D008807:Mice, Inbred BALB C; D018482:Muscle, Skeletal / Q000378:metabolism; D009841:Oligonucleotides; D010957:Plasmids / Q000235:genetics*; D021382:Protein Sorting Signals / Q000235:genetics; D011817:Rabbits
D003062:Codon; D009841:Oligonucleotides; D021382:Protein Sorting Signals; D004921:Erythropoietin