A recent study conducted by researchers at Massachusetts General Hospital (MGH) has shed light on a potential treatment avenue for Alzheimer's disease. The study, published in the journal Neuron, focused on the role of a protein called irisin in breaking down amyloid beta, one of the hallmarks of Alzheimer's disease.
Amyloid beta is a protein fragment that forms plaques between neurons in the brain, blocking important signaling pathways and impairing memory formation. Previous studies have suggested that physical activity and exercise can reduce amyloid beta buildup in the brain and improve cognitive health. However, the underlying mechanisms behind these effects remained unknown.
The researchers used a three-dimensional model of Alzheimer's disease to investigate the role of irisin. They found that exposing the disease models to irisin led to a significant decrease in amyloid beta deposits. Further experiments revealed that irisin was binding to astrocytes, a type of cell in the brain, and stimulating the secretion of an enzyme called neprilysin. Neprilysin is known to degrade amyloid beta and improve memory function in mice with Alzheimer's disease.
The researchers also discovered that irisin downregulates two critical signaling proteins, extracellular signal-regulated kinase (ERK)-signal transducer and activator of transcription 3 (STAT3), to enhance neprilysin levels.
Although the findings are promising, it is important to note that the study was conducted using a three-dimensional cell culture model, which has limitations in accurately mimicking the complexities of the human brain. Animal models, although more advanced, also often fail to accurately predict outcomes in humans. Therefore, further research is needed, including human trials, to validate these findings.
Nevertheless, the study adds to the growing body of evidence highlighting the importance of physical activity for brain health. Alongside irisin, other proteins such as platelet factor 4 and klotho have also shown potential in promoting cognitive function and memory.
Overall, the discovery of irisin's role in breaking down amyloid beta and its potential as a treatment target for Alzheimer's disease opens up new avenues for future research and the development of therapies.