Muscle transfection and permeabilization induced by electrotransfer or pluronic L64: Paired study by optical imaging and MRI.
BACKGROUND
Muscle transfection by electrotranfer is an efficient currently used procedure. Recently, the block copolymer pluronic L64 has been reported to improve muscle transfection. Both procedures are known to permeabilize muscle fibres. Relation between muscle transfection and permeabilization by electrotransfer and L64 was investigated herein.


METHODS
Muscle transfection was evaluated by optical detection of the luciferase reporter gene activity. Muscle permeabilization was evaluated by the uptake of the T1 contrast agent gadolinium-Dotarem (Gd-DOTA) using Magnetic resonance imaging (MRI). Histological examination of muscle sections was also performed.


RESULTS
Electrotransfer and L64 (at a 0.25% concentration) similarly improved muscle transfection, although the interindividual variability was higher for pluronic. On the same animals, the permeabilized volume to the Gd-DOTA was significantly increased after electrotransfer, and L64 from 0.1% to 1%. The concentration of the Gd-DOTA in the permeabilized volume was significantly increased after electrotransfer and L64 at 0.5% and 1%. By histological observation, the inflammation was maximum at day 3 after electrotransfer or L64 injection, and mostly reversed after 7 days. The permeabilized volume and the transfection level correlated for the set of all the conditions tested. However, no significant correlation was observed between Gd-DOTA concentration and transfection.


CONCLUSIONS
It is possible to use successively on the same animals MRI and optical imaging for paired studies of muscle transfection and permeabilization. Permeabilization is possibly not related to gene transfer but it indicates membrane modification related to transfection by the electrotransfer or co-injection of DNA with the L64.
Unité de Pharmacologie Chimique et Génétique & Imagerie, INSERM U 1022, CNRS UMR 8151, Faculté de Pharmacie 4, 75006, Paris, France. michel-francis.bureau@parisdescartes.fr
Michel F
MF
Bureau
Lauriane
L
Jugé
Johanne
J
Seguin
Marie-Noëlle
MN
Rager
Daniel
D
Scherman
Nathalie
N
Mignet
D000818:Animals; D003287:Contrast Media / Q000494:pharmacology*; D018274:Electroporation / Q000379:methods*; D005260:Female; D017930:Genes, Reporter; D006571:Heterocyclic Compounds / Q000494:pharmacology*; D008156:Luciferases / Q000096:biosynthesis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008807:Mice, Inbred BALB C; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000378:metabolism*; D009942:Organometallic Compounds / Q000494:pharmacology*; D020442:Poloxamer / Q000494:pharmacology*; D013997:Time Factors
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; D020442:Poloxamer; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; C514452:pluronic L64; D008156:Luciferases