Non-invasive Bioluminescence Imaging of Myoblast-Mediated Hypoxia-Inducible Factor-1 Alpha Gene Transfer

Purpose

We tested a novel imaging strategy, in which both the survival of transplanted myoblasts and their therapeutic transgene expression, a recombinant hypoxia-inducible factor-1?? (HIF-1??-VP2), can be monitored using firefly luciferase (fluc) and Renilla luciferase (hrl) bioluminescence reporter genes, respectively.

Procedures

The plasmid pUbi-hrl-pUbi-HIF-1??-VP2, which expresses both hrl and HIF-1??-VP2 using two ubiquitin promoters, was characterized in vitro. C2c12 myoblasts stably expressing fluc and transiently transfected with pUbi-hrl-pUbi-HIF-1??-VP2 were injected into the mouse hindlimb. Both hrl and fluc expression were monitored using bioluminescence imaging (BLI).

Results

Strong correlations existed between the expression of hRL and each of HIF-1??-VP2, VEGF, and PlGF (r ²?>?0.83, r ²?>?0.82, and r ²?>?0.97, respectively). In vivo, both transplanted cells and HIF-1??-VP2 transgene expression were successfully imaged using BLI.

Conclusions

An objective evaluation of myoblast-mediated gene transfer in living mice can be performed by monitoring both the survival and the transgene expression of transplanted myoblasts using the techniques developed herein.