SNAP-25a/b Isoform Levels in Human Brain Dorsolateral Prefrontal Cortex and Anterior Cingulate Cortex

Area of Science:

• Neuroscience
• Molecular Psychiatry
• Biomarker Research

Background:

• Synapse plasticity, crucial for brain function, involves the SNAP-25 protein.
• SNAP-25 dysfunction is implicated in neurological and psychiatric disorders like ADHD, bipolar disorder, and schizophrenia.

Purpose of the Study:

• To investigate the association between clinical factors and differential expression of SNAP-25 isoforms.
• To explore SNAP-25 as a potential biomarker in psychiatric conditions.

Main Methods:

• Analysis of SNAP-25 isoform mRNA and protein levels in postmortem human cortex (Brodmann's areas 9 and 24).
• Categorization of subjects by psychiatric diagnosis, mood state, and lifetime impulsiveness.
• Comparison of SNAP-25 levels between diagnostic and clinical groups.

Main Results:

• Alcohol use disorder (AUD) was associated with lower SNAP-25b protein levels in BA24.
• Hispanic subjects exhibited lower SNAP-25a and SNAP-25b mRNA levels in BA9 compared to Anglo-American subjects.
• Smoking status correlated with the total SNAP-25 ratio in BA9/BA24.
• Lower anxious-psychotic symptoms were linked to higher SNAP-25a mRNA in BA24, and altered total SNAP-25 ratios were observed in both high and low symptom groups.

Conclusions:

• Clinical factors, including AUD, ethnicity, smoking, and symptom severity, are associated with differential SNAP-25 expression.
• SNAP-25 levels and isoforms may represent valuable biomarkers extending beyond specific neurological and psychiatric diagnoses.