Investigating Neuroplasticity Changes Reflected by BDNF Levels in Astrocyte-Derived Extracellular Vesicles in...

Area of Science:

• Neuroscience
• Biomarker Discovery
• Psychiatry

Background:

• Depression is linked to the neuroplasticity hypothesis.
• Brain-derived neurotrophic factor (BDNF) is crucial for neuronal function.
• Investigating BDNF in extracellular vesicles may offer new insights into depression.

Purpose of the Study:

• To measure BDNF levels in plasma astrocyte-derived extracellular vesicles (ADEVs).
• To assess if ADEVs can serve as biomarkers for depression.
• To compare plasma BDNF levels with BDNF levels in ADEVs.

Main Methods:

• Collected plasma from 35 patients with major depressive disorder (MDD) and 35 healthy controls (HCs).
• Isolated and validated plasma ADEVs using ultracentrifugation, immunoaffinity capture, and microscopy.
• Quantified BDNF, CD81, and Alix levels in ADEVs and plasma.

Main Results:

• MDD patients showed higher CD81 and lower BDNF levels in ADEVs compared to HCs.
• BDNF levels normalized to CD81 and Alix in ADEVs were also altered in MDD.
• BDNF levels in ADEVs were more stable than in plasma and showed no correlation with plasma BDNF.

Conclusions:

• Altered BDNF levels in ADEVs provide in vivo evidence for the neuroplasticity hypothesis of depression.
• ADEVs show potential as more suitable biomarkers for depression compared to plasma-derived markers.