Remote ischemic post-conditioning promotes hematoma resolution via AMPK-dependent immune regulation

Area of Science:

• Neuroscience
• Immunology
• Cardiovascular Medicine

Background:

• Spontaneous intracerebral hemorrhage (ICH) has high mortality and poor outcomes.
• Hematoma volume is a key determinant of ICH patient prognosis.
• Accelerating clot resolution is crucial for managing ICH.

Purpose of the Study:

• To investigate the effects of remote-limb ischemic post-conditioning (RIC) on hematoma resolution and neurological outcomes after ICH.
• To elucidate the mechanisms underlying RIC's therapeutic effects in ICH.

Main Methods:

• RIC was applied to mice after induced ICH.
• Parabiosis, myeloid cell depletion, and myeloid-specific AMPKα1 inactivation were used to study mechanisms.
• Chimera studies assessed the role of myeloid CD36.

Main Results:

• RIC accelerated hematoma resolution and improved neurological outcomes in mice.
• RIC-induced clot resolution was mediated by humoral factors and enhanced anti-inflammatory macrophage activation.
• Myeloid cell depletion abolished RIC's benefits.
• AMPKα1 inactivation in myeloid cells impaired RIC's effects.
• Myeloid CD36 expression was implicated in RIC-mediated recovery.

Conclusions:

• RIC is a clinically relevant, noninvasive therapy that improves ICH outcomes by modulating innate immune responses.
• RIC enhances hematoma resolution through immunometabolic pathways involving macrophages and AMPKα1.
• Immunometabolic changes induced by RIC may serve as potential biomarkers for therapeutic efficacy monitoring.