Molecular mechanisms in muscular dystrophy : a gene expression profiling study

Abstract

The muscular dystrophies are a group of neuromuscular disorders characterized by progres_sive muscle weakness and wasting. Although the underlying genetic defects of a large number of muscular dystrophies are now know, the molecular mechanisms resulting in the devastating effects of the disease are not yet clear. Furthermore, the muscular dystrophies differ in clinical presentation and severity. The processes responsible for this di_vergence are largely unknown as well. In this thesis, gene expression profiling has been applied to study the molecular and cellular mechanisms and subsequent biological processes that play a role in muscular dystrophy. To characterize the processes associated with regeneration, we have compared gene expression levels in hindlimb muscle tissue of mdx and control mice in a temporal study. Additionally, we have determined the gene expression profiles of dif_ferentiating human myoblasts in vitro, since regeneration processes recapitulate myogenesis. We also set out to compare gene expression levels of different mouse models for muscular dystrophy to find common and distinct molecular mechanisms that underlie different forms of muscular dystrophy. Accordingly, we first had to determine the effects of genetic background variation between inbred mouse strains, and to study the feasibility of alternative experimental designs.