Human PSEN1 Mutant Glia Improve Spatial Learning and Memory in Aged Mice.

Area of Science:

• Neuroscience
• Genetics
• Stem Cell Biology

Background:

• The PSEN1 ΔE9 mutation drives familial Alzheimer's disease (AD) by increasing amyloid-beta 42 (Aβ42) production.
• Previous studies demonstrated that this mutation in human-induced pluripotent stem cell (iPSC)-derived astrocytes elevates Aβ42 and impairs cellular functions.

Purpose of the Study:

• To investigate the behavioral effects of transplanting PSEN1 ΔE9 mutant glial progenitors into newborn mice.
• To analyze the impact of these mutant glia on spatial learning, memory, and brain Aβ42 levels in aged mice.

Main Methods:

• PSEN1 ΔE9 mutant astrosphere-derived glial progenitors were transplanted into newborn mice.
• Mouse behavior was assessed at 8, 12, and 16 months of age.
• Brain tissue analysis included Aβ42 quantification, cell engraftment assessment, and transcriptional profiling.

Main Results:

• Spatial learning and memory were paradoxically improved in 16-month-old male mice transplanted with PSEN1 ΔE9 glia compared to controls.
• This memory enhancement was linked to lower soluble human Aβ42 levels in the brain.
• Reduced engraftment of mutant cells in the cingulate cortex and significant hippocampal gene expression changes were observed.

Conclusions:

• Transplantation of PSEN1 ΔE9 mutant glia can lead to unexpected cognitive benefits in aged mice.
• The beneficial effects may stem from a complex interplay of reduced soluble Aβ42, altered cell engraftment, and transcriptional modifications.
• These findings offer novel insights into the complex role of glial cells and Aβ processing in Alzheimer's disease pathogenesis.