[The BCL-xL and ACR-1 genes promote differentiation and reduce apoptosis in muscle fibers of mdx mice].
The effects of the human BCL-xL and ACR-1 genes on dystrophin expression in cross-striated muscle fibers (CSMF) and on CSMF viability were studied in mdx mice after ballistic cotransfection with the human dystrophin minigene. In control mice, the proportion of dystrophin-positive (D(+)) and dying CSMF were 2.1 +/- 0.1 and 2.1 +/- 0.3%, respectively. Introduction of the dystrophin minigene (20 micrograms of the pSG5dys plasmid) increased the proportions of D(+) and dying CSMF to 5.6 +/- 1.4% and 4.5 +/- 0.9%, respectively. When pSG5dys was introduced along with the pSFFV-Neo plasmid carrying the BCL-xL gene (10 micrograms of each plasmid per shot), the death of CSMF decreased to 3.7 +/- 1% and the proportion of D(+) CSMF significantly (P < 0.05) increased to 12.2 +/- 2.2%. Contransfection with the dystrophin minigene and the BCL-xL gene at 20 micrograms of each plasmid per shot did not stimulate generation of D(+) CSMF, but did reduce the CSMF death to 1.5 +/- 0.3%. Introduction of pSG5dys along with the pRc-CMV-10.1 plasmid containing the ACR-1 gene (10 micrograms of each plasmid per shot) reduced the proportion of D(+) CSMF to 1.1 +/- 0.5% and significantly reduced the proportion of dying CSMF to 0.9 +/- 0.3% as compared with the proportions observed in intact mice or in mice subjected to transfection with pSG5dys. Introduction of the pSG5dys plasmid substantially reduced the proportion of CSMF with peripheral nuclei, suggesting disturbed CSMF differentiation. After cotransfection with the human-dystrophin minigene, the BCL-xL and ACR-1 genes did not affect the extent of CSMF differentiation as compared with that observed in the case of the dystrophin minigene alone. Thus, ballistic transfection of mdx mice with the human dystrophin gene used along with the BCL-xL or ACR-1 gene was shown to suppress the death of muscle fibers and to expedite dystrophin synthesis and cell differentiation.
Mikhaĭlov
V M
VM
Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064 Russia. vmikhailov@mail.cytspb.ru
Kropotov
A V
AV
Zelenin
A V
AV
Krutilina
R I
RI
Kolesnikov
V A
VA
Zelenina
I A
IA
Baranov
A N
AN
Shteĭn
G I
GI
Ostapenko
O V
OV
Tomilin
N V
NV
Baranov
V S
VS
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D016923:Cell Death / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D016189:Dystrophin / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D051379:Mice; D018101:Mice, Inbred mdx; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000502:physiology*; D009363:Neoplasm Proteins; D010544:Peroxidases / Q000235:genetics* / Q000378:metabolism; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D014162:Transfection / Q000379:methods; D051020:bcl-X Protein
C494812:Bcl2l1 protein, mouse; D016189:Dystrophin; D009363:Neoplasm Proteins; C516116:Prdx3 protein, mouse; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; D010544:Peroxidases; C516115:PRDX3 protein, human; D061105:Peroxiredoxin III; D054464:Peroxiredoxins