Treadmill workout activates PPARα in the hippocampus to upregulate ADAM10, decrease plaques and improve cognitive...

Area of Science:

• Neuroscience
• Molecular Biology
• Pharmacology

Background:

• Peroxisome proliferator-activated receptor alpha (PPARα) is present in the hippocampus and involved in amyloid precursor protein (APP) metabolism.
• PPARα regulates non-amyloidogenic APP processing via ADAM10, reducing amyloid plaques and improving cognitive function.
• Mechanisms for upregulating hippocampal PPARα in vivo are not well understood.

Purpose of the Study:

• To investigate the role of regular mild treadmill exercise in upregulating hippocampal PPARα in a mouse model of Alzheimer's disease (5XFAD mice).
• To determine the necessity of PPARα, PPARβ, and PPARγ in mediating the neuroprotective effects of treadmill exercise.
• To elucidate the specific pathways through which PPARα influences cognitive function and plaque pathology.

Main Methods:

• Utilized 5XFAD transgenic mice, including variants lacking PPARα (5XFADΔPPARα) and PPARβ (5XFADΔPPARβ).
• Administered regular mild treadmill exercise to assess its impact on PPARα expression, ADAM10 levels, amyloid plaque load, and cognitive performance.
• Examined the role of PPARγ in regulating ADAM10 transcription in response to exercise.

Main Results:

• Treadmill exercise successfully upregulated PPARα in the hippocampus of 5XFAD mice.
• Exercise failed to improve cognitive function, reduce plaque pathology, or stimulate ADAM10 in 5XFADΔPPARα mice, indicating PPARα's essential role.
• Exercise enhanced ADAM10, reduced plaques, and protected cognition in 5XFADΔPPARβ mice, suggesting PPARβ has a distinct role.
• PPARγ did not influence ADAM10 transcription in exercised 5XFAD mice.

Conclusions:

• Regular treadmill exercise upregulates hippocampal PPARα, which is critical for mediating neuroprotection in Alzheimer's disease models.
• The neuroprotective effects of exercise, including improved cognition and reduced amyloid pathology, are dependent on the presence of PPARα.
• PPARα plays a key role in exercise-induced neuroprotection, while PPARβ contributes to ADAM10 regulation and cognitive benefits.