Dystrophin, utrophin and β-dystroglycan expression in skeletal muscle from patients with Becker muscular dystrophy

Abstract

The precise localization and semiquantitative correlation of dystrophin, utrophin and β-dystroglycan expression on the sarcolemma of skeletal muscle cells obtained from patients with Becker muscular dystrophy (BMD) was studied using three types of double immunofluorescence. Staining intensity was measured using a confocal laser microscope. Each of these proteins was identified at the same locus on the sarcolemma. The staining intensities of dystrophin and utrophin were approximately reciprocal at sarcolemmal sites were dystrophin expression was obviously observed. The staining intensity of β-dystroglycan was strong in areas where dystrophin staining was also strong and utrophin expression was weak. Quantitative analysis revealed that the staining intensity of β-dystroglycan minus that of dystrophin approximated the staining intensity of utrophin, indicating that the sum of dystrophin and utrophin expression corresponds to that of β-dystroglycan. These results suggest that utrophin may compensate for dystrophin deficiency found in BMD by binding to β-dystroglycan.