Increased Expression of Immature Mannose-Containing Glycoproteins and Sialic Acid in Aged Mouse Brains

• Published in: International journal of molecular sciences 2019-12, Vol.20 (24), p.6118
• Main Authors: Simon, Frieder, Bork, Kaya, Gnanapragassam, Vinayaga S, Baldensperger, Tim, Glomb, Marcus A, Di Sanzo, Simone, Ori, Alessandro, Horstkorte, Rüdiger
• Format: Article
• Language: English
• Subjects: Accumulation; Acids; Advanced glycosylation end products; Age; Aging; Alzheimer's disease; Animals; Brain; Brain - metabolism; Carbohydrates; Cell adhesion; Cell adhesion & migration; Cell adhesion molecules; Chromatography, High Pressure Liquid; Enzymes; Epitopes; Glycation End Products, Advanced - metabolism; Glycoproteins; Glycoproteins - analysis; Glycoproteins - metabolism; Glycosylation; Kinases; Male; Mannose; Mannose - chemistry; Mannose - metabolism; Mass Spectrometry; Mice; Monoclonal antibodies; N-Acetylneuraminic Acid - analysis; N-Acetylneuraminic Acid - metabolism; Neural cell adhesion molecule; Neural Cell Adhesion Molecules - metabolism; Polysaccharides; Polysialic acid; Proteins; Receptor for Advanced Glycation End Products - metabolism; Scientific imaging; Signal transduction; Synapsin
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20246118

Aging represents the accumulation of changes in an individual over time, encompassing physical, psychological, and social changes. Posttranslational modifications of proteins such as glycosylation, including sialylation or glycation, are proposed to be involved in this process, since they modulate a variety of molecular and cellular functions. In this study, we analyzed selected posttranslational modifications and the respective proteins on which they occur in young and old mouse brains. The expression of neural cell adhesion molecule (NCAM), receptor for advanced glycation endproducts (RAGE), as well as the carbohydrate-epitopes paucimannose and high-mannose, polysialic acid, and -GlcNAc were examined. We demonstrated that mannose-containing glycans increased on glycoproteins in aged mouse brains and identified synapsin-1 as one major carrier of paucimannose in aged brains. In addition, we found an accumulation of so-called advanced glycation endproducts, which are generated by non-enzymatic reactions and interfere with protein function. Furthermore, we analyzed the expression of sialic acid and found also an increase during aging.