Relationship between utrophin and dystrophin in muscle of patients with several nerve and muscle diseases

Objective To investigate relationship between utrophin and dystrophin in muscle of patients suffered from several neurological muscular diseases.Methods Muscle biopsies of 26 cases of patients suffered from 8 categories neurological muscular diseases and 2 cases of control were analysed for utrophin and dystrophin by immunofluorescence experiments.Results In a majority of Duchenne muscular dystrophy (DMD) patients,their sarcolemma revealed absent,weak or discontinuous fluorescence for dystrophin.In non-DMD muscular dystrophies,lipid storage myopathy,myotonic dystrophy,inflammatory myopathies, neurogenic amyotrophy, polymyositis, mitochondrial encephalomyopathy, myogenic amyotrophy,immunofluorescence reactivity for dystrophin were strongly exhibited in entire sarcolemma.In normal biopsy sample,strong immunofluorescence reactivity for dystrophin was identified in entire sarcolemma,while weak and discontinuous fluorescence was identified on a minority of sarcolemma of DMD patients with severely reduced dystrophin.There was no immunofluorescence reactivity for utrophin in sarcolemma of DMD patients with moderate decreased dystrophin,non-DMD muscular dystrophies and other 6 categories of neurological muscular diseases,nor in sarcolemma of normal biopsies.Conclusions utrophin is expressed in sarcolemma of DMD patients,who have severely reduced dystrophin simultaneously. utrophin is absent in sarcolemma of other categories of neurological muscular diseases including non-DMD muscular dystrophies with normal dystrophin expression and DMD patients with moderately decreased dystrophin.