Glycoproteomics Landscape of Asymptomatic and Symptomatic Human Alzheimer's Disease Brain

ABSTRACT: Alterations of protein abundance and post-translational modifications in patients with Alzheimer’s disease (AD), such as glycosylation, phosphorylation, and ubiquitination, and their roles in disease progression and treatment outcome are areas of intense study. Little is known, however, about the overall N-glycosylation of proteins in human brains, and those from Alzheimer’s patients, particularly in regard to large-scale intact N-linked glycoproteomics analysis. To elucidate the glycoproteome landscape, we developed an approach based on multi-lectin affinity enrichment, hydrophilic interaction chromatography (HILIC), and LC-MS-based glycoproteomics analysis. We analyzed 10 normal, 10 asymptomatic, and 10 symptomatic AD brains, in which we detected >300 glycoproteins and >1,900 glycoforms across the samples. The majority of glycoproteins have N-glycans that are high-mannosidic and complex chains that are fucosylated and bisected. The Man5 N-glycan was found to occur most frequently at >20% of the total glycoforms. Unlike the glycoproteomes of other tissues, sialylation is a minor feature of the brain glycoproteome, occurring at <9% of N-glycans . We observed changes in the number of antennae, frequency of fucosylation, bisection, and other monosaccharides at individual glycosylation sites among normal, asymptomatic, and symptomatic AD samples. Further analysis revealed glycosylation differences in subcellular compartments. We did not observe a statistical difference between male and female patients. These results represent the first glycoproteomics landscape of brains from multiple AD individuals, which will facilitate a deeper understanding of AD and possible disease treatment options.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Brain

DISEASE(S): Alzheimer's Disease

SUBMITTER: Suttipong Suttapitugsakul  

LAB HEAD: Richard D. Cummings

PROVIDER: PXD032219 | Pride | 2022-10-31

REPOSITORIES: Pride