Measuring microRNA reporter activity in skeletal muscle using hydrodynamic limb vein injection of plasmid DNA combined with in vivo imaging

Background microRNA regulation plays an important role in the remodeling that occurs in response to pathologic and physiologic stimuli in skeletal muscle. In response to stress, microRNAs are dynamically regulated, resulting in a widespread “fine-tuning” of gene expression. An understanding of this dynamic regulation is critical to targeting future therapeutic strategies. Experiments elucidating this dynamic regulation have typically relied on in vitro reporter assays, ex vivo sample analysis, and transgenic mouse studies. Surprisingly, no experimental method to date allows rapid in vivo analysis of microRNA activity in mammals.