Increased expression of activin A in the spinal cords of rats with clip compression injuries

Abstract

Activin A, a member of transforming growth factor β superfamily, plays roles in neuroprotection and immunomodulation. The expression of activin A was studied in the inflammatory lesions of rats with spinal cord injury (SCI) by Western blotting and immunohistochemistry. Western blotting showed that levels of activin A in core lesions in rats with SCI were significantly increased at day 1 (p<0.05) and day 4 post-injury (p<0.01) compared to sham control spinal cords, and were significantly lower at day 7 post-injury compared to day 4 post-injury (p<0.05). Immunohistochemical analysis revealed constitutive expression of activin A in vessels and neurons in the spinal cords of sham control rats. After SCI, activin A was also detected in inflammatory cells in the core lesion, particularly in isolectin B4-positive macrophages and glial cells. Collectively, our results suggest that a transient increase in activin A levels after clip compression injury may contribute to the modulation of inflammation during SCI.