Reducing microglial activity in the presence of apolipoprotein E4 (APOE4) has uncovered a mechanism associated with the deposition of misfolded amyloid and tau in a novel mouse model of Alzheimer’s disease. By transplanting human neurons into the mouse brain and eliminating the mouse microglia, scientists at the Gladstone Institutes in San Francisco observed that amyloid and tau deposition was reduced. These results support therapeutic strategies that target APOE4 and microglia.

Using microglia and an unbiased screening method, investigators have identified almost 60 previously unknown targets for γ-secretase. Investigators from KU Leuven and colleagues published their results in Molecular Cell on Nov. 16, 2023.

The broadest view of post-mortem brains in Alzheimer’s disease (AD) has unveiled the genome, transcriptome and epigenome alterations of this neurodegenerative condition. The coordinated research, directed by scientists at the Massachusetts Institute of Technology (MIT), also described new cellular pathways that could help the scientific community design new therapies. Four simultaneous studies published on Sept. 28, 2023, in Cell, presented a brain single-cell atlas of AD, exposed the damage that affects DNA, and described the processes that alter the microglia and dysregulate the epigenome.

The broadest view of post-mortem brains in Alzheimer’s disease (AD) has unveiled the genome, transcriptome and epigenome alterations of this neurodegenerative condition. The coordinated research, directed by scientists at the Massachusetts Institute of Technology (MIT), also described new cellular pathways that could help the scientific community design new therapies. Four simultaneous studies published on Sept. 28, 2023, in Cell, presented a brain single-cell atlas of AD, exposed the damage that affects DNA, and described the processes that alter the microglia and dysregulate the epigenome.

Alzheimer’s disease (AD) has a new candidate for its treatment. Nasal anti-CD3 monoclonal antibody (MAb) reduced microglia activation in the brain of mice without its effect being dependent on the β-amyloid (Aβ) deposits characteristic of this neurodegenerative disorder. “We have done many basic studies in the laboratory on microglia. Microglia activation occurs in many neurologic diseases. One of them is multiple sclerosis (MS). And it also occurs in AD,” senior author Howard Weiner told BioWorld.

In brain research, be it basic or clinical, neurons have long hogged the limelight. But at the 2023 European Meeting on Glial Cells in Health and Disease, neurons take a back seat to glia – cell types that have often been described as support cells and treated as an afterthought, but that play critical roles in all aspects of brain function, including information processing.

“One of the many reasons we don’t have effective therapies for AD at the moment ... is that we don’t understand the beginnings of the disease,” Constanze Depp told BioWorld. Understanding those beginnings is likely to be a necessary prerequisite for truly turning the tide on Alzheimer’s disease (AD). “The brain is so bad at repairing itself, and once a neuron is lost, it will most likely not regenerate,” she elaborated. Now, Depp and her colleagues have reported on a contributor to those beginnings.

While microglia constitute the immune cells of the brain, their potential role in the early development of neuronal circuitry is poorly understood. Investigators at the Karolinska Institutet, together with eight other institutions, characterized an anatomically distinct microglial cell population identified as expressing the arginase-1 (ARG1) enzyme.

Implanting brain organoids into the brains of mice may allow the more realistic study of microglial cells during both healthy and disease states. This is what researchers from the Salk Institute and their collaborators found in a study published on May 11, 2023, in Cell.