Advanced lipid peroxidation end-products in Alexander's disease.

Rosenthal fibers (RF), intra-astrocytic hyaline inclusions, accumulate in various pathological conditions and are the histological hallmark of Alexander's disease. While the major protein components of RF have been identified, the factors accounting for their pathogenesis, accumulation, and insolubility are largely unknown. In this study, we immunohistochemically examined three cases of Alexander's disease using antibodies to a lysine-derived pyrrole modification arising from 4-hydroxy-2-nonenal, a highly cytotoxic reactive aldehyde produced by lipid peroxidation. In all the cases of Alexander's disease examined, strong immunolabeling of RF by the antibodies to 4-hydroxy-2-nonenal pyrrole adducts were noted. By contrast, age-matched control cases showed no immunoreactivity. These results indicate that modification of protein by lipid peroxidation adducts may play an important role in the formation of RF as well as in the pathogenesis of Alexander's disease. Furthermore, taken together with our previous data indicating advanced Maillard reaction end products in RF, it seems that post-translational modification of RF, initiated by oxidative stress, is critical for both the accumulation and the insolubility of RF, and therefore, by inference, in the pathogenesis of Alexander's disease.