FAM222A and amyloid plaque deposition in Alzheimer's Disease

项目总结

PROJECT SUMMARY Alzheimer's disease (AD) is the leading cause of dementia in the elderly, characterized by neurofibrillary tangles, senile plaques and a progressive loss of neuronal cells in neocortex and hippocampus. Currently, there is no effective treatment for AD. Less than 10% of AD cases are early onset with only a small fraction caused by autosomal dominantly inherited genetic changes in APP, presenilin 1 (PS1) or presenilin 2 (PS2), all of which are responsible for the overproduction of Aβ and the earlier formation of amyloid plaques. Though more than 90% of AD cases are referred to as sporadic AD without family history, they have the similar clinical and pathologic phenotypes as sporadic AD. Despite a large body of evidence suggests that Aβ deposition in the brain as the likely culprit playing a critical role in the pathogenesis of AD or related dementia, the molecular pathomechanisms of amyloid plaque formation remain largely elusive. Interestingly, in our recent study, we have identified a novel protein Aggregatin specifically accumulated within the centers of amyloid plaques. Aggregatin is predominantly expressed in the central nervous system and increased in brains of patients with AD or amyloid precursor protein (APP) transgenic mice for AD. Excitingly, Aggregatin physically interacts with Aβ with very high affinity, and remarkably facilitates Aβ aggregation even under near-physiologic nanomolar concentrations. Forced expression of Aggregatin resulted in increased amyloid deposition, whereas ablation of Aggregatin suppressed the formation of amyloid plaques in APP transgenic mice, further implying it as an important factor for Aβ aggregating to form amyloid plaques. These exciting and promising preliminary studies suggest that a detailed investigation into the potential role of Aggregatin in the formation of amyloid plaques in AD is warranted. Using a novel transgenic mouse model with conditional ablation of Aggregatin, this study will not only study whether and how Aggregatin regulates amyloid plaque formation and disease progression, but also test the feasibility of targeting Aggregatin as a novel therapeutic approach for AD. Amyloid plaque is a prominent common histopathological feature of in various major neurodegenerative diseases including but not limited to AD. Our proposed studies of Aggregatin and its connection with amyloid plaque will have very broad scientific and translational significance.