Myoblast survival enhancement and
transplantation success improvement by Heat-Shock treatment in mdx mice
Bouchentouf,
Manaf; Benabdallah, Basma F.; Tremblay, Jacques P.
Transplantation. 77(9):1349-1356, May 15, 2004
Abstract
Background. Duchenne
muscular dystrophy is a disease caused by the incapacity to synthesize
dystrophin, which is implicated in the maintenance of the sarcolemma integrity.
Myoblast transplantation is a potential treatment of this disease. However,
most of the transplanted cells die very rapidly after their injection.
Heat-shock proteins (HSPs) are over-expressed when cells undergo various types
of stresses. Our goal was thus to investigate whether the expression of HSPs
(HSP70 in particular) could protect myoblasts from death after intramuscular
injection.
Methods. HSP70 expression was induced by warming the cells at 42[degrees]C for
60 minutes. HSP70 over-expression was quantified by Western blot analysis. The
in vitro effect of HSPs on cell survival was evaluated by fluorescence-activated
cell sorter analysis using the Hoescht/propidium iodide-labeling technique, and
their in vivo effects were investigated by transplanting TnI-LacZ myoblasts
labeled with [methyl-14C] thymidine.
Results. Western blots indicated a sevenfold over-expression of the HSP70 after
the heat-shock treatment. In vitro, the heat-shock treatment protected 18% of
the cells from staurosporine- (1 [mu]M) induced apoptosis. HSPs also protected
10% of the cells from death induced by either tumor necrosis factor-[alpha] (30
ng/mL) or glucose oxydase (0.1 U/mL). In vivo, the treatment improved the cell
survival by twofold 5 days after the graft and increased by fourfold the
long-term graft success.
Conclusions. The heat-shock treatment is a practical approach for improving the
success of myoblast transplantation; in fact, using this kind of treatment,
there is no need to genetically modify the cells before their transplantation.