Changes in glycoprotein carbohydrate content in the aging human brain.

Area of Science:

• Neuroscience
• Biochemistry
• Gerontology

Background:

• Brain glycoproteins are crucial for neuronal function.
• Changes in glycosylation patterns are implicated in brain aging.

Purpose of the Study:

• To investigate age-related alterations in brain glycoprotein carbohydrate composition.
• To identify specific changes in oligosaccharide structures during human brain aging.

Main Methods:

• Analysis of total carbohydrate concentration in human brain tissue from individuals aged 25-85 years.
• Characterization of various oligosaccharide types, including N-linked and O-linked structures.

Main Results:

• Total carbohydrate concentration per gram of fresh brain tissue showed no significant change with age.
• Significant shifts were observed in specific oligosaccharide types.
• N-glycosidically linked complex sialooligosaccharides (tri- and tetraantennary) decreased with age.
• N-linked mannose-high oligosaccharides (ovalbumin type), N-linked biantennary sialoglycopeptides (transferrin type), and O-linked oligosaccharides increased with age.
• Increased sulfate ester groups in N-linked sialoglycopeptides and decreased phosphorylated high mannose oligosaccharides were noted.

Conclusions:

• While total brain glycoprotein carbohydrate content is stable, the composition of oligosaccharide structures undergoes significant remodeling during aging.
• These shifts in specific glycan structures may have implications for brain function and health in older adults.