Transforming growth factor-β1 and fibrosis in congenital muscular dystrophies

We evaluated transforming growth factor-beta 1 (TGF-beta 1) expression in the muscle of four laminin alpha 2-negative, Four laminin alpha 2-positive and seven partial laminin alpha 2-deficient congenital muscular dystrophy (CMD) patients, and compared it to Duchenne muscular dystrophy (DMD) patients and controls. TGF-beta 1 mRNA levels in skeletal muscle from laminin alpha 2-negative and laminin alpha 2-positive CMD patients were significantly greater than in controls (P < 0.05 and P < 0.005, respectively), while in partial laminin alpha 2-deficient muscular dystrophy patients the amount was not significantly higher than in controls (P > 0.1). The TGF-beta 1 values were lower than those found in DMD, although the extent of fibrosis was greater in CMD than in DMD and controls. Our findings suggest that TGF-beta 1 is involved in CMD muscle fibrosis, but differently from what we observed in DMD muscles as it seems not to be the major player in connective tissue proliferation. (C) 1999 Elsevier Science B.V. All rights reserved.