Preconditioning exercise reduces hippocampal neuronal damage via increasing Klotho expression in ischemic rats

Area of Science:

• Neuroscience
• Molecular Biology
• Exercise Physiology

Background:

• Oxidative stress significantly contributes to neuronal damage following cerebral ischemia.
• Klotho, an anti-aging protein, mitigates oxidative stress by enhancing manganese superoxide dismutase (MnSOD) expression in the nervous system.
• Physical activity is known to increase Klotho expression.

Purpose of the Study:

• To investigate the neuroprotective effects of preconditioning exercise on hippocampal Klotho and MnSOD expression in a rat model of ischemic stroke.
• To evaluate the impact of exercise on neuronal activity, brain infarction, and working memory after middle cerebral artery occlusion (MCAO).

Main Methods:

• Rats underwent a 3-week preconditioning exercise regimen (treadmill running).
• An experimental stroke model (MCAO) was employed to induce cerebral ischemia.
• Hippocampal Klotho and MnSOD expression, CA1 neuronal activity, neurological scores, brain infarction volume, and working memory (Y-maze test) were assessed.

Main Results:

• MCAO led to reduced hippocampal Klotho and MnSOD expression, decreased CA1 neuronal activity, impaired working memory, and larger infarction areas compared to sham controls.
• Preconditioning exercise normalized Klotho and MnSOD levels, preserved CA1 neuronal activity, improved neurological scores, reduced brain infarction, and prevented working memory deficits in MCAO rats.
• A significant positive correlation was observed between Klotho and MnSOD expression levels.

Conclusions:

• Preconditioning exercise exerts significant neuroprotective effects against ischemic stroke in rats.
• Upregulation of Klotho and MnSOD by exercise appears to be a key mechanism underlying its neuroprotective benefits.
• Klotho shows potential as a neuroprotective protein in ischemic stroke, particularly concerning antioxidant defense.