Voluntary exercise alleviates ischemic brain injury in mice by modulating mitochondrial dysfunction.

Area of Science:

• Neuroscience
• Mitochondrial Biology
• Exercise Physiology

Background:

• The interplay between physical activity and mitochondrial health in neurological conditions like ischemic stroke remains incompletely understood.
• Mitochondrial dynamics and apoptosis are critical cellular processes implicated in neuronal survival and brain injury.

Purpose of the Study:

• To investigate the therapeutic effects of voluntary exercise on mitochondrial dynamics and apoptosis in a mouse model of ischemic stroke.
• To elucidate the molecular mechanisms underlying exercise-induced neuroprotection in the context of middle cerebral artery occlusion (MCAO).

Main Methods:

• Utilized a middle cerebral artery occlusion (MCAO) model in 54 male C57BL/6 J mice.
• Assessed brain injury using H&E staining and infarct volume measurement.
• Quantified mitochondrial dynamics (DRP1, FIS1, OPA1) and apoptosis markers (cytochrome c, cleaved caspase-3) via Western blotting and immunofluorescence.

Main Results:

• Voluntary exercise significantly improved behavioral scores and reduced infarct volume in MCAO mice.
• Exercise intervention reversed MCAO-induced cortical damage and normalized mitochondrial dynamics by modulating DRP1, FIS1, and OPA1 expression.
• Down-regulation of cytochrome c and caspase-3 pathway components indicated inhibition of mitochondrial apoptosis.

Conclusions:

• Voluntary exercise demonstrates a significant neuroprotective effect against ischemic stroke.
• Exercise-induced benefits are mediated through the regulation of mitochondrial dynamics and the suppression of the mitochondrial apoptotic pathway.