July 25, 2024

New Study Suggests Brain Fungal Infection Could Lead to Alzheimer’s Disease-like Changes

A recent study conducted by researchers at Baylor College of Medicine and collaborating institutions has found a potential link between brain fungal infections and the development of Alzheimer’s disease-like symptoms. While previous research has hinted at a connection between fungi and chronic neurodegenerative conditions like Alzheimer’s disease, the mechanisms involved have remained poorly understood.

Using animal models, the researchers focused on the fungus Candida albicans and its impact on brain cells. They discovered that this fungus enters the brain by producing enzymes called secreted aspartic proteases (Saps) that break down the blood-brain barrier. Once inside the brain, Candida albicans causes damage that resembles Alzheimer’s disease.

Further investigation showed that the fungus activates two separate mechanisms in brain cells called microglia, leading to effective clearance of the infection. The first mechanism involves the breakdown of the amyloid precursor protein into toxic protein fragments called amyloid beta (Ab)-like peptides. These peptides activate microglia via a receptor called Toll-like receptor 4, keeping the fungal load low in the brain. The second mechanism involves a protein produced by Candida albicans called candidalysin, which binds to microglia via another receptor called CD11b. Activation of microglia through this pathway is crucial for clearing the infection.

The researchers suggest that these findings contribute to a better understanding of Alzheimer’s disease development. The current understanding is that the accumulation of toxic Ab-like peptides in the brain leads to neurodegeneration. It has been assumed that these peptides are produced endogenously by the brain itself. However, this study shows that Candida albicans can also produce Ab-like peptides, adding a different source to the equation. The common fungus, which has been detected in the brains of individuals with Alzheimer’s disease and other neurodegenerative disorders, has its own set of proteases capable of generating the same toxic peptides.

The team proposes that the aggregates of Ab-like peptides found in Candida-associated neurodegenerative conditions, including Alzheimer’s disease and Parkinson’s disease, may be generated both by the brain and by Candida albicans. The study’s findings in animal models indicate the need for further research to evaluate the role of Candida albicans in Alzheimer’s disease development in humans. These findings could potentially lead to innovative therapeutic strategies in the future.

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  1. Source: Coherent Market Insights, Public sources, Desk research
  2. We have leveraged AI tools to mine information and compile it