Remote Ischemic Postconditioning vs. Physical Exercise After Stroke: an Alternative Rehabilitation Strategy?

Area of Science:

• Neuroscience
• Stroke Rehabilitation
• Ischemic Conditioning

Background:

• Therapeutic physical exercise shows promise for stroke rehabilitation but faces clinical challenges.
• Remote ischemic postconditioning (RIPostC) is a potential neuroprotective method with fewer understood rehabilitation mechanisms.
• Debates persist regarding optimal neuroprotection and rehabilitation strategies for acute ischemic stroke.

Purpose of the Study:

• To compare the rehabilitative properties and underlying mechanisms of physical exercise and RIPostC in a rat model of ischemic stroke.
• To investigate the role of hypoxia-inducible factor-1α (HIF-1α) in mediating the neuroprotective and rehabilitative effects of these interventions.

Main Methods:

• 248 adult male Sprague-Dawley rats were assigned to sham, stroke, stroke with intense exercise, stroke with mild exercise, or stroke with RIPostC groups.
• Neuroprotection was assessed via infarct volume and neurological deficits; long-term function was evaluated using multiple neurobehavioral tests.
• Mechanisms were explored by measuring mRNA and protein levels of neuroplasticity factors (HIF-1α, BDNF, TrkB, CREB) and using a HIF-1α inhibitor (YC-1).

Main Results:

• Both exercise and RIPostC significantly reduced infarct volume and neurological deficits compared to the stroke group.
• All treatment groups demonstrated improved neurobehavioral outcomes, with RIPostC showing comparable or superior results.
• RIPostC and exercise increased neuroplasticity markers; HIF-1α inhibition abolished most beneficial effects, highlighting its crucial role.

Conclusions:

• Remote ischemic postconditioning (RIPostC) offers significant neuroprotection and rehabilitation benefits for ischemic stroke, potentially surpassing physical exercise.
• The hypoxia-inducible factor-1α (HIF-1α) pathway, possibly through HIF-1α/BDNF/TrkB/CREB signaling, is a key mediator of neuroplasticity and the efficacy of these interventions.