These findings suggest that (1) LB pathology can influence the clinical features of familial AD, (2) the E184D mutation of presenilin-1 may be associated with the LB formation through Abeta overproduction, although the process of LB formation is strongly affected by other unknown mechanisms, (3) in neurodegenerative disorders with LBs, there is a common pathophysiological background inducing NAC accumulation in neuritic plaques and astrocytes, and (4) the NAC accumulation in neuritic plaques is modulated by the abnormally aggregated tau protein.
These findings suggest that the insR352 PSEN1 is not pathogenic, and the IVS1+1G-->A mutation in PGRN causes FTDP associated with FTLD-U pathology and represents a new class of neurodegenerative disease--the 'hypoprogranulinopathies'.
In conclusion, (1) a frontal lobe syndrome-like personality change may be one of the characteristic clinical features of early-onset CWP-AD, (2) the deposition pattern of Abeta40 and Abeta42 in CWP-AD is more variable than that of presenilin-1-linked cases, (3) Abeta deposition can result in development of dementia without tau pathology, and (4) CWP-AD with LBs and several other neurodegenerative disorders with LBs share a common process involving alpha-synuclein and NAC deposition.
We present multiple lines of evidence suggesting links between neurodegenerative disease and glial cell types in human, including human-specific correlation of presenilin-1 with oligodendrocyte markers, and significant enrichment for known neurodegenerative disease genes in microglial modules.
A localization of PS1 and PS2 in mitochondria-associated membranes may help reconcile the disparate hypotheses regarding the pathogenesis of Alzheimer disease and may explain many seemingly unrelated features of this devastating neurodegenerative disorder.