Exosomes are small vesicles secreted by most cell types including neurons that 
function in intercellular communication through transfer of their cargo or 
encapsulate and eliminate unnecessary cellular components and therefore have a 
broad impact on nerve development, activation and regeneration. In addition, 
exosomes have been observed to be involved in spreading pathological misfolded 
proteins, thereby leading to the onset and propagation of disease. Alzheimer 
disease (AD) is the most common form of dementia and characterized by two types 
of lesions: amyloid plaques and neurofibrillary tangles. Accumulating evidence 
has demonstrated that exosomes are associated with amyloid precursor (APP) and 
Tau proteins and play a controversial role in Alzheimer's disease process. In 
this review, we will discuss the role of exosomes in the metabolism and 
secretion of APP and Tau proteins and their subsequent impact on AD 
pathogenesis.