Poststroke hyperglycemia dysregulates cap-dependent translation in neural cells.

Area of Science:

• Neuroscience
• Molecular Biology
• Translational Medicine

Background:

• Post-stroke hyperglycemia impairs functional recovery.
• Hyperglycemia upregulates the cap-dependent translation regulator 4E-BP1.
• Protein translation is crucial for neuronal survival and repair after stroke.

Purpose of the Study:

• To investigate if hyperglycemic ischemic reperfusion injury (I/R) affects normal protein translation post-stroke.
• To test the hypothesis that high glucose levels disrupt protein synthesis pathways in the brain following ischemic stroke.

Main Methods:

• Rat primary cortical neurons (PCNs) exposed to oxygen-glucose deprivation (OGD) with varying glucose concentrations.
• In vivo study using transient middle cerebral artery occlusion (t-MCAO) in hyperglycemic rats.
• Immunoblotting and immunostaining to analyze protein phosphorylation and expression.

Main Results:

• High glucose impaired neurite growth and reduced S6 ribosomal protein phosphorylation in PCNs.
• Hyperglycemia led to HIF-1α destabilization and sustained VEGF levels.
• In vivo, hyperglycemic stroke models showed decreased phosphorylated 4E-BP1 and S6 ribosomal protein.

Conclusions:

• Hyperglycemic I/R injury is associated with dysregulated cap-dependent translation post-stroke.
• Impaired protein translation, particularly affecting 4E-BP1 and S6, is linked to poor outcomes.
• Further research into HIF-1α and translation regulation may offer therapeutic strategies for hyperglycemic stroke.