Search Results (2)

Amyloid beta (Aβ) oligomers are key mediators of synaptic dysfunction and neural circuit impairment in Alzheimer’s disease (AD). While plasma Aβ oligomerization propensity (OAβ) correlates with cerebral amyloid pathology and cognitive decline, the systemic modulators of OAβ remain poorly understood. In this study, we identified the albumin interactome (albumin and its associated proteins) as a critical regulator of OAβ. Selective depletion of the albumin interactome from plasma eliminated the OAβ difference between amyloid PET (A-PET)- and A-PET+ individuals. Proteomic analysis revealed widespread network alterations within the albumin interactome of A-PET+ individuals. Notably, vitronectin (VTN) was identified as a key hub protein that was significantly reduced in A-PET+ individuals. Functional assays and in silico modeling demonstrated that VTN directly bound to Aβ and inhibited its oligomerization. Additionally, plasma VTN levels distinguished A-PET status. These findings suggest that systemic changes in the albumin interactome, particularly the reduction in VTN, are associated with dysregulated Aβ dynamics in plasma. Our results provide novel insights into systemic mechanisms underlying AD pathology and identify VTN as a potential peripheral modulator and biomarker of cerebral amyloid pathology. Full article

A pathogenic mutation in presenilin-1 (PSEN1), His214Asn, was found in a male patient with memory decline at the age of 41 in Korea for the first time. The proband patient was associated with a positive family history from his father, paternal aunt, and paternal grandmother without genetic testing. He was diagnosed with early onset Alzheimer’s disease (EOAD). PSEN1 His214Asn was initially reported in an Italian family, where the patient developed phenotypes similar to the current proband patient. Magnetic resonance imaging (MRI) scans revealed a mild hippocampal atrophy. The amyloid positron emission tomography (amyloid-PET) was positive, along with the positive test results of the increased amyloid ß (Aβ) oligomerization tendency with blood. The PSEN1 His214 amino acid position plays a significant role in the gamma–secretase function, especially from three additional reported mutations in this residue: His214Asp, His214Tyr, and His214Arg. The structure prediction model revealed that PSEN1 protein His214 may interact with Trp215 of His-Trp cation-π interaction, and the mutations of His214 would destroy this interaction. The His-Trp cation-π interaction between His214 and Trp215 would play a crucial structural role in stabilizing the 4th transmembrane domain of PSEN1 protein, especially when aromatic residues were often reported in the membrane interface of the lipid–extracellular region of alpha helices or beta sheets. The His214Asn would alter the cleavage dynamics of gamma–secretase from the disappeared interactions between His214 and Trp215 inside of the helix, resulting in elevated amyloid production. Hence, the increased Aβ was reflected in the increased Aβ oligomerization tendency and the accumulations of Aβ in the brain from amyloid-PET, leading to EOAD. Full article