Poststroke Induction of α-Synuclein Mediates Ischemic Brain Damage

Area of Science:

• Neuroscience
• Molecular Biology
• Pathology

Background:

• Alpha-synuclein (α-Syn) is implicated in Parkinson's disease and other synucleinopathies.
• The role of α-Syn in acute neurodegenerative disorders like stroke remains unclear.
• Stroke involves complex pathophysiological mechanisms that may involve α-Syn.

Purpose of the Study:

• To investigate the role of α-Syn in poststroke brain damage.
• To determine if preventing α-Syn expression is neuroprotective after stroke.
• To explore α-Syn as a potential therapeutic target for stroke.

Main Methods:

• Induction of transient focal ischemia in adult rodent models.
• Assessment of α-Syn protein expression and localization.
• α-Syn knockdown and knockout studies.
• Evaluation of infarct volume and neurological recovery.
• Analysis of molecular markers of mitochondrial fragmentation, oxidative stress, apoptosis, and autophagy.
• Investigation of serine-129 phosphorylated α-Syn (pα-Syn) and its kinase, PLK2.

Main Results:

• Transient focal ischemia upregulated α-Syn expression and nuclear translocation.
• α-Syn knockdown or knockout significantly reduced infarct size and improved neurological recovery.
• α-Syn knockdown attenuated postischemic markers of mitochondrial dysfunction, oxidative stress, apoptosis, and autophagy.
• Ischemia increased serine-129 phosphorylation (pα-Syn) and nuclear translocation of α-Syn.
• Mice lacking PLK2 (kinase for S129 phosphorylation) showed improved outcomes after ischemia.

Conclusions:

• α-Syn contributes to neuronal damage and functional deficits after stroke.
• Reducing α-Syn expression or blocking its S129 phosphorylation is neuroprotective.
• α-Syn represents a promising therapeutic target for minimizing brain damage following stroke.