Overexpressed MicroRNA-455-3p enhances cognitive function in late-onset Alzheimer's disease

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• MicroRNAs (miRNAs) are critical regulators in neurodegenerative diseases like Alzheimer's disease (AD).
• The specific role of miR-455-3p in cognitive and motor functions related to AD was previously unexplored.

Purpose of the Study:

• To investigate the impact of miR-455-3p overexpression and knockout on cognitive and motor behaviors in a humanized amyloid beta (hAbKI) mouse model of AD.

Main Methods:

• Generated double mutant mice by crossing miR-455-3p transgenic (TG) and knockout (KO) mice with hAbKI mice.
• Assessed cognitive and motor functions using Morris Water Maze, Y-maze, open field, and rotarod tests across six experimental groups.

Main Results:

• miR-455-3p overexpression significantly improved locomotor activity, working memory, spatial learning, and motor coordination.
• miR-455-3p knockout impaired cognitive and motor performance and increased anxiety-like behavior.
• The hAbKI x miR-455-3p KO group showed the most severe deficits, indicating miR-455-3p loss exacerbates AD-related impairments.

Conclusions:

• miR-455-3p plays a crucial role in regulating cognitive and motor functions.
• Overexpression of miR-455-3p demonstrates neuroprotective benefits.
• Targeting miR-455-3p presents a potential therapeutic strategy for improving outcomes in AD and related disorders.