Cyclophilin D deficiency improves mitochondrial function and learning/memory in aging Alzheimer disease mouse model

Area of Science:

• Neuroscience
• Mitochondrial Biology
• Alzheimer's Disease Research

Background:

• Mitochondrial stress and amyloid-beta (Aβ) toxicity are early features of Alzheimer disease (AD).
• Cyclophilin D (CypD) mediated mitochondrial permeability transition pore (mPTP) is implicated in neuronal and synaptic stress caused by Aβ and oxidative stress.

Purpose of the Study:

• To investigate the long-term protective effects of CypD deficiency in aged Alzheimer disease (AD) mouse models.
• To evaluate the impact of CypD abrogation on mitochondrial function and cognitive performance in late-stage AD.

Main Methods:

• Utilized transgenic AD-type mice (mAPP) with and without CypD deficiency.
• Assessed mitochondrial function (calcium-induced swelling, calcium uptake, respiratory function) in aged mice (22-24 months).
• Evaluated spatial learning and memory performance in aged mAPP mice with and without CypD deficiency.

Main Results:

• CypD deficient mAPP mice showed reduced calcium-induced mitochondrial swelling and enhanced mitochondrial calcium uptake capacity.
• Preserved mitochondrial respiratory function was observed in aged CypD deficient mAPP mice.
• Improved spatial learning and memory were evident in aged CypD deficient mAPP mice, despite advanced AD pathology.

Conclusions:

• CypD deficiency confers persistent, life-long protection against Aβ toxicity in an AD mouse model.
• Abrogation of CypD preserves mitochondrial and synaptic function and cognitive abilities even in old age.
• Targeting CypD represents a promising therapeutic strategy for Alzheimer disease treatment.