Src homology 2 domain-containing inositol-5’ phosphatase in a murine model of Amyotrophic Lateral Sclerosis

As Src homology-2 domain-containing inositol-5’ phosphatase (SHIP-1) expression has been implicated in inflammation, immunoreactivity against SHIP-1 was evaluated in mice over-expressing mutant superoxide dismutase (mSOD-1) and wild-type (wt) mice. Spinal cord sections were examined at 11 weeks, 15 weeks of age and at end-stage. SHIP-1 immunoreactivity was detected in mSOD-1 mice at end-stage when considerable motor disability is evident, and at 15 weeks, but not in wt mice. At 15 weeks, SHIP-1 was prominent in the ventral horn, and by end-stage, immunoreactivity was detected throughout the ventral and dorsal regions. SHIP-1 localization was explored further using SHIP-1 immunoreactivity and antibodies directed against microglia and astrocytes. SHIP-1 was not detected in microglia but was detected in astrocytes and this cell specific localization of immunoreactivity suggests that astrocytes can express SHIP-1. The expression of SHIP-1 in astrocytes may be involved in the pathogenesis of murine amyotrophic lateral sclerosis.