Study explores gene interactions in Alzheimer's disease across brain regions

Alzheimer's disease (AD), a neurodegenerative disorder marked by amyloid plaque buildup and cognitive decline, remains a challenging condition to understand at the molecular level. While substantial research has focused on the disease's pathology, much remains unknown about how gene interactions contribute to disease progression. Traditional models have limitations, particularly in terms of spatial resolution and capturing gene dynamics across different regions of the brain. Given these challenges, there is an urgent need to explore how genes interact in different brain regions and at various stages of Alzheimer's to better understand its mechanisms.

Published (DOI: 10.1016/j.gendis.2024.101337) in Genes & Diseases on May 22, 2024, a team of researchers from Sun Yat-sen University, Central South University, Tulane University, and the University of Kansas employs cutting-edge spatial transcriptomics (ST) to investigate the complex gene interactions in AD. By analyzing data from both mouse models and human samples, the research identifies how gene associations in key brain regions, like the hippocampus (HP) and entorhinal cortex (ENTI), change with age and disease progression. The study highlights key genes, including Ttr and Trem2, that behave differently across different phenotypes, offering new insights into their roles in AD and opening the door to potential therapeutic targets.

The study dives deep into AD by examining how gene interactions vary across age groups and brain regions. Using ST from both App knock-in mouse models and human samples, researchers mapped the gene activity in critical brain areas like the HP and ENTI. They discovered that genes such as Ttr, involved in amyloid-beta clearance, and Trem2, an AD risk factor, displayed different behaviors depending on the stage of the disease and the age of the individual. For example, while Ttr exhibited a higher network degree in younger, healthy brains, it showed altered interactions in older, AD-affected brains. Similarly, Trem2 showed differential expression across the two brain regions, indicating a complex role in lipid metabolism and the blood-brain barrier. The study also highlighted how ligand-receptor (L-R) interactions change over time, with significant shifts between the 3-month and 18-month groups, potentially affecting immune response and plaque clearance. Moreover, the research mapped transcription factor (TF) networks, which showed how different regions in the HP and ENTI regulate synaptic and cognitive functions, providing crucial insights into AD's molecular underpinnings.

Dr. Hongwen Deng, a leading expert in Alzheimer's research, commented on the study's findings: "This research is a major advancement in understanding the molecular dynamics of AD. By capturing gene interactions at both high spatial and temporal resolutions, the study provides new insights into how Alzheimer's evolves at the genetic level. The identification of age-specific gene networks and regional interactions could be key in developing more effective, personalized treatments for the disease, offering hope for slowing or even preventing its devastating effects on brain function."

The findings from this study offer a new approach to studying AD by focusing on gene networks that change over time and across brain regions. The identification of genes like Ttr and Trem2 provides potential biomarkers for early detection and therapeutic targets. Understanding the spatio-temporal dynamics of gene interactions could lead to more precise, personalized treatment strategies for Alzheimer's patients. Future research with higher-resolution datasets will refine these insights and could lead to innovative treatments that target the disease at different stages, ultimately helping to slow its progression and improve patient outcomes.