Increased expression of phospholipase D1 in the spinal cords of rats with experimental autoimmune encephalomyelitis.

Phospholipase D1 (PLD1) expression was studied in the central nervous system (CNS) under the condition of induced experimental autoimmune encephalomyelitis (EAE) in Lewis rats. After inducing EAE, the expression of PLD1 was analyzed by Western blot and immunohistochemistry. Western blot analysis showed that expression of the isozymes PLD1 significantly increased in the spinal cord at the peak stage of EAE, and declined thereafter. Immunohistochemistry showed that PLD1-positive cells increased in number in EAE lesions, which consisted mainly of ED1-positive macrophages and glial fibrillary acidic protein-positive astrocytes. In contrast, PLD1 was only weakly expressed in some spinal cord astrocytes in control rats. These results suggest that PLD1 is increased in autoimmune CNS inflammation, and possibly involved in the activation of macrophages and astrocytes in EAE lesions.