Immunohistochemical Study on the Deposition of Apolipoprotein E in Cerebral and Islet Amyloidoses in Cynomolgus Monkeys (Macaca fascicularis).

Abstract
To investigate the role of apolipoprotein E (apo E) in amyloidoses of cynomolgus monkeys, the localization of apo E in cerebral amyloid, including senile plaques and cerebrovascular amyloid, and in islet amyloid was examined immunohistochemically. Mature types of senile plaques with amyloid deposits and cerebrovascular amyloid showed intense immunoreactivity to both antisera to apo E and amyloid β protein (Aβ). In contrast, diffuse plaques without obvious Congophilic amyloid showed weak immunoreactivity to antiserum to apo E, but intense reactivity to antiserum to Aβ. In addition, the number of these apo E-positive diffuse plaques was small compared with that of Aβ-positive plaques. On the other hand, diabetic islet amyloid that was negative with Aβ, reacted intensely with antiserum to apo E. These findings suggest that apo E plays an important role in amyloid fibril formation in several types of amyloidoses.