1. Supplemental Figure 1. Remicade treatment did not affect body weight and muscle weight in mdx mice. Mdx mice were treated with Remicade (10 mg/ml) starting either at 2 weeks or 7 months of age for 6 or 7 weeks correspondingly. No significant different was revealed between treated and untreated groups of animals. Vertical bars on all graphs represent standard error. Statistics were assessed by two tailed t-test with significance set at p<0.05. BodyMuscles 9 mo BodyMuscles mdx (n=9) mdx-Remicade (n=10) mdx (n=5) mdx-Remicade (n=6) 2 mo

2. Supplemental Figure 2. Echocardiography of 20mg/kg treated mdx mice. Mdx mice were treated with Remicade (20 mg/kg) and control antibody provided by Centocor (20 mg/kg) for 8 months, starting at 6 weeks of age (Exp 3, table 1). Echocardiography was performed at the end of the treatment period. Vertical bars represent standard error. No significant differences were observed in heart rate, left ventricular (LV) mass and ejection fraction (EF), fractional shortening (FS) and ratio between early and late ventricular filling velocity (E/A) as observed by two tailed t-test with significance set at p<0.05 mdx (n=4)mdx-Remicade (n=5) p=0.02

3. mdxmdx-Remicademdx-Enbrel B A. Summary intensity/muscle volumeAverage voxel intensity n=4 n=5 n=4 n=5 mdxmdx-Enbrelmdx-Remicade Supplemental Figure 3. Magnetic Resonance Imaging did not reveal improvements following Remicade treatment. Magnetic resonance imaging of the quadriceps muscles of mdx mice injected with Remicade (3 mg/kg), Enbrel (4 mg/kg) or control for Remicade (3 mg/kg) for 6 months starting at age of 6 weeks of age (once weekly dosing). (A) graphs of quantitated MRI data representing calculated intensity per muscle volume, average voxel intensity and muscle volume and muscle weight normalized per body weight; (B) representative T2 maps. Vertical bars represent standard error and statistics were assessed by two tailed t-test with significance set at p<0.05. n=4 n=5 B. Muscle weight/body weight D.C. Muscle Volume Mdx, n=8 Remicade, n=10

4. Supplemental Figure. 4: Remicade treatment did not affect abnormal deposits of calcium in diaphragm of mdx mice treated with various doses of the drug. The von Kossa stain was utilized to access mineralization in diaphragm tissue sections of mdx mice treated with Remicade. Shown are representative pictures of the diaphragms of mdx mice treated with Remicade at concentrations 20 mg/kg (A) or 3 mg/kg (B) mdxmdx-Remicade A 20 mg/kg mdxmdx-Remicade B 3 mg/kg

5. mdxmdx-Enbrelmdx-Remicade Supplemental Figure 5 Expression of inflammatory genes in diaphragms of mdx mice treated with Remicade (3 mg/kg) and Enbrel (4 mg/kg) for 6 months starting at age of 6 weeks as assessed by real-time PCR. Expression of IL-6, β-TGF, iNOS and osteopontin mRNAs were accessed in diaphragms of mdx mice by quantative PCR. GAPDH PCR is used as cDNA control. Data are shown in graph as average Starting Quantity (SQ) for the gene normalized by SQ for GAPDH. Vertical bars on all graphs represent standard error. Statistics were assessed by two tailed t-test with significance set at p<0.05. iNOS/GAPDH iNOS ß-TGF/GAPDH ß-TGF IL-6/GAPDH IL-6 osteopontin/GAPDH OSTEOPONTIN p=0.02 diaphragms

6. mdx mdx-Enbrel mdx-Remicade Supplemental Figure 6: α-Laminin staining of hearts of mdx mice after prolonged treatment (6 months) with Remicade (3 mg/kg) or Enbrel (4 mg/kg).

7. mdx (n=5) mdx-Enbrel (n=5) mdx-Remicade (n=7) mdx (n=6) mdx-Enbrel (n=6) mdx-Remicade (n=7) mdx (n=5) mdx-Enbrel (n=6) mdx-Remicade (n=7) IGFbp/GAPDH ratio IGFbp hearts p=0.02 p=0.01 mdx (n=6) mdx-Enbrel (n=5) mdx-Remicade (n=7) TGF beta hearts TGFbeta/GAPDH ratio Supplemental Figure 7. Prolonged treatment (6 months) of mdx mice with Remicade (3 mg/kg) or Enbrel (4 mg/kg) decreases myostatin content in the hearts of treated animals while did not significantly affect TGF beta as estimated by quantative PCR. Levels of myostatin, TGF beta and various IGF binding peptides were assessed by quantitative, real time PCR in the hearts of untreated mdx mice compared with Remicade and Enbrel-treated animals. GAPDH PCR is used as a cDNA control. Real-time PCR data is shown in graph as average Starting Quantity (SQ) for the gene normalized by SQ for GAPDH. Vertical bars on all graphs represent standard error. Statistics were assessed by two tailed t-test with significance set at p<0.05.

8. Phospho-CAMKII CAMKII Loading mdx Remicade Enbrel Supplemental Figure 8. CAMKII and phospho-CAMKII content in heart lysates of mdx mice after prolonged treatment (6 months) with Remicade (3 mg/kg) or Enbrel (4 mg/kg). Levels of CAMKII and phospho-CAMKII were estimated by Western blotting in the hearts of untreated mdx mice compared with Remicade and Enbrel-treated animals. Specific antibody were utilized to evaluate protein content in heart homogenates prepared in the presence of phosphatase and protease inhibitors. Blots were analyzed by ImageJ software and specific signals were normalized for loading. All values were expressed as percent of average mdx normalized signal. Vertical bars on all graphs represent standard error. Statistics were assessed by two tailed t-test with significance set at p<0.05. % hearts