Role of thrombospondin 1 in macrophage inflammation in dysferlin myopathy

J Neuropathol Exp Neurol. 2010 Jun;69(6):643-53. doi: 10.1097/NEN.0b013e3181e0d01c.


Muscle inflammation can be a prominent feature in several muscular dystrophies. In dysferlin myopathy, it is mainly composed of macrophages. To understand the origin of inflammation in dysferlin-deficient muscle, we analyzed soluble factors involved in monocyte chemotaxis released by myoblasts and myotubes from control and dysferlinopathy patients using a transwell system. Dysferlin-deficient myotubes released more soluble factors involved in monocyte chemotaxis compared with controls (p < 0.001). Messenger RNA microarray analysis showed a 3.2-fold increase of thrombospondin 1 (TSP-1) expression in dysferlin-deficient myotubes. Retrotranscriptasepolymerase chain reaction analysis, ELISA, and immunohistochemistry confirmed these results. Dysferlin mRNA knockdown with short-interfering RNA in normal myogenic cells resulted in TSP-1 mRNA upregulation and increased chemotaxis. Furthermore, monocyte chemotaxis was decreased when TSP-1 was blocked by specific antibodies. In muscle biopsies from dysferlinopathy patients, TSP-1 expression was increased in muscle fibers but not in biopsies of patientswith other myopathies with inflammation; TSP-1 was seen in some macrophages in all samples analyzed. Taken together, the data demonstrate that dysferlin-deficient muscle upregulates TSP-1 in vivoand in vitro and indicate that endogenous chemotactic factors arecrucial to the sustained inflammatory process observed in dysferlinopathies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blotting, Western
  • Cell Movement / physiology
  • Cells, Cultured
  • Dysferlin
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunohistochemistry
  • Inflammation / genetics*
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Leukocytes, Mononuclear / cytology
  • Leukocytes, Mononuclear / metabolism
  • Macrophages / metabolism*
  • Macrophages / pathology
  • Male
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism*
  • Muscle Fibers, Skeletal / cytology
  • Muscle Fibers, Skeletal / metabolism*
  • Muscle Fibers, Skeletal / pathology
  • Muscle Proteins / genetics*
  • Muscle Proteins / metabolism*
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / metabolism*
  • Muscular Dystrophies / pathology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Thrombospondin 1 / genetics
  • Thrombospondin 1 / metabolism*


  • DYSF protein, human
  • Dysferlin
  • Membrane Proteins
  • Muscle Proteins
  • RNA, Messenger
  • Thrombospondin 1