New light shed on origins of Alzheimer’s

A groundbreaking study has shed new light on the genetic underpinnings of Alzheimer’s disease.

The research has unearthed a critical mutation within a key gene operating in the brain’s immune cells, potentially elevating the risk of Alzheimer’s disease.

The study, led by experts from Indiana University School of Medicine, will add further to insight around the disease which is so crucial in developing therapies. 

The focal point of the investigation revolved around the phospholipase C gamma 2 (PLCG2) gene, intricately entwined within microglia—central to the brain’s immune response. 

This genetic anomaly, discovered through analysis of the gene’s biological workings, showcased the impact of specific rare variants. 

The study found that the M28L variant heightened the susceptibility to Alzheimer’s disease, whereas the P522R variant exhibited a risk-reducing effect.

Innovative mouse models of Alzheimer’s disease developed by the NIH-funded MODEL-AD Center allowed researchers to substantiate their findings. 

Immune cells harbouring risk-reducing gene variants demonstrated a reduction in amyloid plaques, while those carrying the risk-elevating variants exhibited a surge in plaque accumulation. 

The study unveiled specific gene clusters orchestrating these alterations in immune cell behaviour within microglia.

Microglia, often regarded as the brain’s first line of defence against infections, toxins and damage, has garnered attention for its significant role in influencing disease susceptibility.

“The microglial response affects neurons which then affects the capacity to learn and form new memories,” researcher Dr Gary Landreth said.

Extensive collaboration within Stark Neurosciences Research Institute enabled a comprehensive evaluation of the gene’s implications. 

This included a comparison between preclinical data from animal models and real-world human data on Alzheimer’s disease.

“This represents a collaboration that could’ve only been achieved at Stark,” Dr Landreth said. 

“We used human genetics to investigate and identify a mechanism, and indeed we have.”