Abstract

Glycosylation has been found to be altered in the brains of individuals with Alzheimer’s disease (AD). However, it is unknown which specific glycosylation-related pathways are altered in AD dementia. Using publicly available RNA-seq datasets covering seven brain regions and including 1724 samples, we identified glycosylation-related genes ubiquitously changed in individuals with AD. Several differentially expressed glycosyltransferases found by RNA-seq were confirmed by qPCR in a different set of human medial temporal cortex (MTC) samples (n = 20 AD vs. 20 controls). N-glycan-related changes predicted by expression changes in these glycosyltransferases were confirmed by mass spectrometry (MS)-based N-glycan analysis in the MTC (n = 9 AD vs. 6 controls). About 80% of glycosylation-related genes were differentially expressed in at least one brain region of AD participants (adjusted p-values < 0.05). Upregulation of MGAT1 and B4GALT1 involved in complex N-linked glycan formation and galactosylation, respectively, were reflected by increased concentrations of corresponding N-glycans. Isozyme-specific changes were observed in expression of the polypeptide N-acetylgalactosaminyltransferase (GALNT) family and the alpha-N-acetylgalactosaminide alpha-2,6-sialyltransferase (ST6GALNAC) family of enzymes. Several glycolipid-specific genes (UGT8, PIGM) were upregulated. The critical transcription factors regulating the expression of N-glycosylation and elongation genes were predicted and found to include STAT1 and HSF5. The miRNA predicted to be involved in regulating N-glycosylation and elongation glycosyltransferases were has-miR-1-3p and has-miR-16-5p, respectively. Our findings provide an overview of glycosylation pathways affected by AD and potential regulators of glycosyltransferase expression that deserve further validation and suggest that glycosylation changes occurring in the brains of AD dementia individuals are highly pathway-specific and unique to AD.

Details

Title
Transcriptomic and glycomic analyses highlight pathway-specific glycosylation alterations unique to Alzheimer’s disease
Author
Tang, Xinyu 1 ; Tena, Jennyfer 2 ; Di Lucente, Jacopo 3 ; Maezawa, Izumi 3 ; Harvey, Danielle J. 4 ; Jin, Lee-Way 3 ; Lebrilla, Carlito B. 2 ; Zivkovic, Angela M. 1 

 University of California, Davis, Department of Nutrition, Davis, USA (GRID:grid.27860.3b) (ISNI:0000 0004 1936 9684) 
 University of California, Davis, Department of Chemistry, Davis, USA (GRID:grid.27860.3b) (ISNI:0000 0004 1936 9684) 
 University of California, Davis, Department of Pathology and Laboratory Medicine, School of Medicine, Sacramento, USA (GRID:grid.27860.3b) (ISNI:0000 0004 1936 9684); UC Davis MIND Institute, Sacramento, USA (GRID:grid.27860.3b) (ISNI:0000 0004 1936 9684) 
 University of California, Davis, Division of Biostatistics, Department of Public Health Sciences, School of Medicine, Davis, USA (GRID:grid.27860.3b) (ISNI:0000 0004 1936 9684) 
Pages
7816
Publication year
2023
Publication date
2023
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2813775469
Copyright
© The Author(s) 2023. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.