Neutrophil-Secreted Enzymes and ALS Risk: Exploring a Potential Mechanistic Link.

Area of Science:

• Neuroimmunology
• Neurology
• Biomarkers

Background:

• Peripheral immunity, particularly neutrophils, is implicated in amyotrophic lateral sclerosis (ALS) pathogenesis.
• Previous research linked elevated neutrophil counts to increased ALS risk and progression.
• Mechanisms connecting neutrophils to ALS occurrence, especially via neutrophil-secreted enzymes, require elucidation.

Purpose of the Study:

• To investigate the role of specific neutrophil-secreted enzymes in the occurrence of amyotrophic lateral sclerosis (ALS).
• To explore potential mechanisms, including axonal damage, through which these enzymes might influence ALS onset.

Main Methods:

• Utilized UK Biobank-Proteomics Platform data for six neutrophil-secreted enzymes.
• Employed Cox proportional hazards regression to assess enzyme associations with ALS occurrence.
• Conducted mediation analysis to evaluate the role of neurofilament light chain (NfL) in enzyme-mediated ALS onset.

Main Results:

• Significantly higher levels of neutrophil-secreted enzymes were detected in individuals who later developed ALS, indicating pre-disease neutrophil activation.
• Elevated enzyme levels correlated with increased ALS occurrence risk and NfL concentrations.
• Myeloperoxidase (MPO) and S100A12 enzyme effects on ALS onset were partially mediated by axonal injury.

Conclusions:

• Increased levels of neutrophil-secreted enzymes are associated with a higher risk of developing ALS.
• These enzymes provide mechanistic insights into neutrophil involvement in ALS.
• Neutrophil-secreted enzymes represent potential therapeutic targets for ALS intervention.