Altered serum content of brain-derived neurotrophic factor isoforms in multiple sclerosis

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Brain-derived neurotrophic factor (BDNF) has dual roles in multiple sclerosis (MS), potentially offering neuroprotection while also promoting disease by sustaining autoreactive T cells.
• The distinct functions of BDNF protein isoforms—pro-BDNF (pro-apoptotic), mature BDNF (pro-survival), and truncated BDNF (unknown function)—remain underexplored in MS.

Purpose of the Study:

• To investigate the relative serum levels of BDNF isoforms in relapsing-remitting MS patients compared to healthy controls.
• To explore potential clinical correlations of BDNF isoform levels in MS.

Main Methods:

• Enzyme-linked immunosorbent assay (ELISA) and semi-quantitative Western-blot were employed to analyze BDNF isoforms in serum samples.
• Serum samples from 20 relapsing-remitting MS patients and 20 age/gender-matched healthy controls were analyzed.

Main Results:

• Total serum BDNF was lower in MS patients compared to healthy controls.
• The percentage of mature BDNF and pro-BDNF was significantly decreased in MS patients, while truncated BDNF increased.
• Increased serum Fas (sFas) was observed in MS patients; no correlations were found between BDNF isoform percentages and clinical/demographic features.

Conclusions:

• The findings suggest that altered BDNF isoform processing in MS may contribute to impaired apoptotic deletion of autoreactive T cells and reduced neuroprotection.
• Increased truncated BDNF might represent a compensatory mechanism.
• Future research on MS should consider the significance of BDNF proteolytic processing.