Remote Limb Ischemic Postconditioning Protects Against Ischemic Stroke by Promoting Regulatory T Cells Thriving

Area of Science:

• Neuroscience
• Immunology
• Metabolomics

Background:

• Remote limb ischemic postconditioning (RLIPoC) shows promise in protecting against ischemic stroke.
• The precise mechanisms of RLIPoC's cross-organ protective effects, particularly involving immune modulation, require further investigation.

Purpose of the Study:

• To elucidate the underlying mechanisms of RLIPoC in mitigating ischemic brain injury.
• To investigate the role of regulatory T cells (Tregs) and metabolic alterations in RLIPoC-mediated neuroprotection.

Main Methods:

• Ischemic stroke was induced in mice via middle cerebral artery occlusion.
• RLIPoC was applied, followed by assessment of Treg percentages in spleen, blood, and brain using flow cytometry.
• Metabolic profiling, Treg depletion studies, and evaluation of infarct volume and neurological deficits were performed.

Main Results:

• RLIPoC significantly reduced infarct volume and improved neurological function post-stroke.
• RLIPoC increased Treg populations in the spleen, blood, and ischemic brain hemisphere.
• Metabolic changes, including alterations in flavin adenine dinucleotide and nicotinamide adenine dinucleotide hydrate, were observed; nicotinamide adenine dinucleotide hydrate mimicked RLIPoC's Treg-boosting effect.

Conclusions:

• RLIPoC confers neuroprotection against ischemic brain injury.
• The protective effects are mediated, at least in part, by the activation and maintenance of Tregs.
• The nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide hydrate pathway is implicated in RLIPoC-induced Treg modulation and neuroprotection.