Abscence of laminin alpha1 chain in the skeletal muscle of dystrophic dy/dy mice.

In Duchenne muscular dystrophy (DMD) and laminin alpha2 defective congenital muscular dystrophies (CMD) there are reports of an induction of laminin alpha1 chain in regenerating muscle fibers. These studies are based on immunohistochemistry data with one monoclonal antibody alone. Based on these data we sought to establish if the laminin alpha1 chain is induced in the muscle of dy/dy mice. We found no evidence of induction of laminin alpha1 chain protein or mRNA in dystrophic dy/dy skeletal muscle fibers as determined by immunohistochemistry, Western blotting, Northern blotting, or PCR analysis. Our data point to the need for additional immunological reagents specific for human laminin-alpha1 to resolve whether the conflicting data on laminin-alpha1 distribution in human and mouse tissues is due to species differences or, alternatively, due to differences in reagent specificity. Our data might be important when designing therapy strategies for CMD.