New role for dystrophin and utrophin in the actin cytoskeletal network


Muscle Regeneration in Disease (includes satellite cells)

Poster Number: 105


Alex Andre, Jason Newbern, Alan Rawls, PhD


1. Arizona State University, 3. Arizona State University

Duchenne’s muscular dystrophy (DMD) is a recessive X-linked form of muscular dystrophy, which affects 1 in 3,600 males, resulting in muscle degeneration and death. DMD is caused by mutations in the dystrophin gene, a muscular protein that links the internal cytoskeletal system of individual myofibers to structural proteins within the extracellular matrix. The disease leads to progressive symmetric muscle weakness, muscle degeneration and its substitution with fat and connective tissue, causing random and progressive loss of contractile function. In recent years dystrophin has been shown to be more than just a transmembrane protein and theorized to play a role in transmembrane protein organization, signaling, and actin structure. Utilizing mice deficient for both dystrophin and it’s sister gene, utrophin, we looked at the role of these proteins in the organization of the actin cytoskeletal network. Using a Zeiss LSM800 confocal with a Plan-Apochromat 20x/0.8 M27 objective, we imaged large tilesets of muscle to assess the fluorescent intensity of F-actin and G-actin. We observed a decrease of F-actin in Dmdmdx/mdx/UTRN-/- muscle. This is associated with an increase in G-actin which suggests that dystrophin and utrophin play a role in the stabilization of the F-actin cytoskeleton and overall function of muscle fibers.