Therapeutic potential of DDQ in enhancing mitochondrial health and cognitive function in Late-Onset Alzheimer's disease.

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline, mitochondrial dysfunction, and neuroinflammation. This study evaluates the therapeutic potential of DDQ, a small molecule in the humanized Abeta knockin (hAbKI) mice that represents late-onset AD. Our findings demonstrate that DDQ treatment significantly improves cognitive performance as assessed through behavioral tests, including the rotarod, open field, Y-maze, and Morris water maze, compared to untreated hAbKI mice. At the molecular level, DDQ promoted mitochondrial biogenesis, as evidenced by enhanced expression of key proteins like PGC1α, NRF1, and TFAM. Additionally, DDQ treatment facilitated mitophagy, as indicated by elevated levels of PINK1 and Parkin, and reduced neuroinflammation, reflected by decreased Iba1 and GFAP levels. Transmission electron microscopy analysis revealed a marked improvement in mitochondrial morphology, with increased mitochondrial length and reduced mitochondrial numbers in DDQ-treated mice. Furthermore, DDQ treatment led to an increase in mitophagic vacuoles, suggesting that it effectively removes dysfunctional mitochondria. Taken together, for the first time, our study results support the potential of DDQ as a promising neuroprotective agent for late-onset AD, addressing mitochondrial dysfunction, neuroinflammation, and cognitive decline. Our study focused on developing small molecules that modulate mitophagy, mitochondrial dynamics and neuroinflammatory pathways for aging, AD and other neurodegenerative disorders.