Glycomic and Proteomic Changes in Aging Brain Nigrostriatal Pathway

Area of Science:

• Neuroscience
• Gene Therapy
• Glycobiology

Background:

• Parkinson's disease (PD) involves progressive loss of dopaminergic neurons.
• Gene therapy using adeno-associated viruses (AAV) shows promise but faces efficacy challenges in human trials.
• AAV binding relies on glycan receptors, which may change with age.

Purpose of the Study:

• To investigate age-related changes in glycan receptors (heparan sulfate and N-glycans) in the rat nigrostriatal pathway.
• To identify how these changes impact AAV binding and gene delivery for Parkinson's disease therapy.

Main Methods:

• Analysis of striatum and substantia nigra in young versus aged rats.
• Assessment of heparan sulfate (HS) disaccharide profiles.
• Evaluation of N-glycan composition, focusing on terminal galactose.
• Proteomic analysis of the nigrostriatal pathway.

Main Results:

• Observed distinct brain region- and age-specific HS disaccharide profiles.
• Identified age- and brain region-specific N-glycan profiles, particularly terminal galactose units.
• Detected brain region-specific alterations in protein expression within the aging nigrostriatal pathway.

Conclusions:

• Age-related alterations in HS and N-glycans within specific brain regions impact AAV receptor availability.
• These glycan and proteomic changes likely contribute to reduced AAV transduction efficiency in aged individuals.
• Findings provide critical insights for designing improved AAV vectors for Parkinson's disease gene therapy.