Abstract
Identification of the proteinaceous components of the pathological inclusions is an important step in understanding the associated disease mechanisms. We immunohistochemically examined two previously reported cases with eosinophilic neuronal cytoplasmic inclusions (NCIs)(case 1, Mori et al. Neuropathology 2010; 30: 648–53; case 2, Kojima et al. Acta Pathol Jpn 1990; 40: 785–91) using 67 antibodies against proteins related to cytoskeletal constituents, ubiquitin-proteasome system, autophagy-lysosome pathway and stress granule formation. Regional distribution pattern of eosinophilic NCIs in case 1 was substantially different from that in case 2. However, NCIs in both cases were immunonegative for ubiquitin and p62 and were immunopositive for stress granule markers as well as autophagy-related proteins, including valosin-containing protein. Considering that eukaryotic stress granules are cleared by autophagy and valosin-containing protein function, our findings suggest that eosinophilic NCIs in the present two cases may represent the process of autophagic clearance of stress granules.