Limb Remote Ischemic Postconditioning Improves Glymphatic Dysfunction After Cerebral Ischemia-Reperfusion Injury

Area of Science:

• Neuroscience
• Cerebrovascular Biology
• Cellular Biology

Background:

• Delayed neuronal damage is a significant consequence of cerebral ischemia-reperfusion (I/R) injury.
• Glymphatic system dysfunction contributes to ischemic brain edema and neuroinflammation following I/R.
• Understanding glymphatic system changes post-I/R is crucial for developing neuroprotective strategies.

Purpose of the Study:

• To investigate glymphatic system alterations after cerebral ischemia-reperfusion (I/R) injury.
• To determine if limb remote ischemic postconditioning (LRIP) can enhance glymphatic function and offer neuroprotection.

Main Methods:

• A focal brain I/R mouse model was established using middle cerebral artery occlusion/reperfusion (MCAO/R).
• Glymphatic function was assessed using immunofluorescence, TEM, and Western Blot assays.
• Evaluated parameters included CSF flow, brain swelling, aquaporin-4 (AQP4) expression and polarization, and amyloid-β (Aβ) deposition.

Main Results:

• Cerebrospinal fluid (CSF) flow was disturbed, and AQP4 polarization decreased early in cerebral ischemia.
• AQP4 polarity reduction and Aβ deposition increased from 12 to 72 hours of reperfusion.
• LRIP increased β-DG and AQP4 polarization, reduced Aβ deposition, and improved glymphatic function.

Conclusions:

• Cerebral ischemia-reperfusion injury leads to impaired glymphatic system function in mice.
• LRIP demonstrates potential neuroprotective effects by enhancing glymphatic system function post-I/R.