A. Baranov et al., Local and distant transfection of mdx muscle fibers with dystrophin and LacZ genes delivered in vivo by synthetic microspheres, GENE THER, 6(8), 1999, pp. 1406-1414
Patterns of dystrophin and beta-galactosidase expression were examined in m
dx mice after i.m. injections of synthetic microspheres (MF-2) loaded with
full-length (pHSADy) or mini-dystrophin gene (pSG5dys) cDNA plasmid constru
cts or with LacZ marker gene (pCMV-LacZ). A single injection of 25 mu g pHS
ADy into quadriceps femoris muscle resulted in 6.8% of dystrophin positive
myofibers (DPM) in a given muscle; 8.4% of DPM in glutaeus muscle and 4.3%
of DPM in quadriceps femoris muscle of contralateral limb on day 21 after e
xposure compared with only 0.6% DPM in intact (non-injected) mdx mice. A hi
gh proportion of DPM (17.6% and 10.8%, respectively) was registered in both
injected and contralateral muscles after mini: gene cDNA administration. M
F-2/dystrophin cDNA particles were detected by FISH analysis in about 60-70
% of myofiber nuclei in muscles of injected and contralateral limbs 7 days
after application. The presence of human dystrophin cDNA and its products i
n all skeletal muscles and in different infernal organs was proven by PCR a
nd RT-PCR analysis. Patches of beta-galactosidase expression were abundant
in injected muscle, and frequent in the contralateral and other skeletal mu
scles as well as in diaphragm, heart and lungs. High levels of dystrophin c
DNA expression, and an efficient distant transfection effect with preferent
ial intranuclei inclusion of MF-2 vehicle, are very encouraging for the dev
elopment of a new constructive strategy in gene therapy trials of DMD.