The Expression Of MuRF-1 And MAFbx In Duchenne Muscular Dystrophy And To Analysis Clinical And Pathological Features

Objective Duchenne muscular dystrophy is an X-linked recessive genetic disease mainly involved in skeletal muscle which pathogenesis is related to the DMD gene mutation resulting in dystrophin deficiency.Although the pathogenesis is clear, mechanism of degradation of muscle protein is remains unclear.Recent studies show that the ATP-ubiquitin-proteasome pathway (UPP) take part in the process of muscle atrophy.E3 ubiquitin ligase is the key enzyme in UPP pathway,especially the MuRF-1 and MAFbx which specific express in skeletal and cardiac muscle and play an important role in the process of muscle protein degradation.The purpose of this study is to find whether skeletal muscle of DMD patients have abnormal expression of MuRF-1 and MAFbx.We also wish this study could contribute to the new strategy for curing Duchenne muscle.Methods Select patients clinically suspected DMD,treated by muscle biopsy. According to anti-dystrophin-N,-C,-R monoclonal antibody staining, DMD patients 35 cases present on deficency of dystrophin protein (0-2). The control group 25 cases select patients from orthopedics who suffer acute trauma without neuromuscular disease.All the patients are treated with immunohistochemical stain of anti-MuRF-1,anti-MAFbx. The result is analyzed with Image Analysis Software,and analyze the relationship between course of the disease, pathological changes, Dys deletion with MuRF-1,MAFbx. Using t test and Pearson correlation to analyse the date,P <0.05 is considered statistically significant.Results 1. Clinical analysis:average diagnosis age of 35 cases is 7.18±3.17 years olds; mean age of onset is 3.45±2.60 years old.The main purpose to clinic is manifestations of myasthenia,for example,go up staircase difficultly,unable to stand after squatting, fall walk easily.2.The expression of MuRF-1 and MAFbx are higher in integral optical density and average optical density than control group,there are significant differences (P<0.05).With the extension of the course of disease and pathological changes serious,the expression of MuRF-1 and MAFbx increase(P<0.05).There are not significantly different between patients whoes Dys expression is 0,1, 2 deletion and MuRF-1, MAFbx expression(P>0.05).Conclusions 1.The expression of MuRF-1 and MAFbx in muscle of DMD patients are increased, and with the extension of course, pathological changes serious, the expression of MuRF-1, MAFbx increased suggesting that UPP pathway maybe involved in the degradation of muscle protein.2. MuRF-1, MAFbx expression has nothing to do with whether to keep a small number of Dys-positive fibers.