Expression levels of TGF-β1 and CTGF are associated with the severity of Duchenne muscular dystrophy

The present study aimed to analyze the association of transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) expression levels in skeletal muscle with the clinical manifestation of Duchenne muscular dystrophy (DMD). A total of 18 cases of DMD, which were confirmed by routine pathological diagnosis were recruited into the present study, along with 8 subjects who suffered from acute trauma but did not present any neuromuscular diseases and were enrolled as the healthy controls. Immunohistochemical staining was used to detect the expression levels of CTGF and TGF-β1 in muscle biopsy specimens. Furthermore, Spearman rank correlation analysis was conducted among the expression levels of CTGF and TGF-β1, age, clinical severity and pathological severity in DMD patients. The immunohistochemical staining results revealed that the expression levels of CTGF and TGF-β1 were significantly increased in the DMD group compared with those in the control group (P<0.05). These levels were not found to be significantly correlated with the onset age (P>0.05), but there was a significant correlation with the degree of pathology and clinical severity (P<0.05). In conclusion, an upregulated expression of CTGF and TGF-β1 was revealed in the skeletal muscle of DMD patients, which were in positive correlation with the degree of pathology and clinical severity. These two factors may be involved in the pathophysiology of fibrosis in DMD.