Figure 5.

Characterization of the ability of engineered myoblast expressing antiinflammatory substance to reduce the poor survival of the injected cells. The survival of the myoblasts engineered to express IL-1Ra was compared with the nonengineered control cells. The nonengineered cells were rapidly lost 48 h after injection (Control myoblast). In contrast, the cells engineered to express IL-1Ra significantly reduced the early loss of the injected cells (IL-1Ra– expressing myoblast): only 20% of the injected cells seemed to be lost 48 h after injection. However, a significant reduction in the amount of β-galactosidase expression was observed 24 h after injection in comparison to the noninjected myoblasts. We observed a high number of transduced myofibers that persisted between day 2 and day 5 after injection of the IL-1Ra expressing myoblasts (C and D). The absence of significant difference for both populations of cells at 0 and 0.5 h after injection suggested that the loss of myoblasts was minimal during injection. *P < 0.05 when compared with transduced noninjected myoblasts (0 h). Bar, 50 μm.