In the relentless pursuit to find effective treatments for Alzheimer’s disease, researchers have spotlighted a potential new ally: the hormone irisin, which is generated during physical exercise. This revelation brings a beacon of hope, suggesting a potential new frontier in Alzheimer’s therapy.
According to a recent study carried out by a team at the Massachusetts General Hospital in Boston, the elevation of irisin levels, encouraged through physical exercise, showcases promising results in reducing the plaque and tau tangles that are trademarks of Alzheimer’s disease. The role of irisin had been previously linked to the regulation of glucose and lipid metabolism in adipose tissue and the acceleration of the conversion of white fat tissue to brown, a process that augments energy expenditure.
Before delving deeper into irisin’s impact on Alzheimer’s, the team had pioneered the development of 3D human cell culture models of the disease. These models played a pivotal role in understanding how irisin interacts with amyloid-beta, a significant player in the Alzheimer’s landscape, present in the brain.
Previous studies on murine models had affirmed the beneficial effects of physical exercise in diminishing amyloid-beta accumulations, albeit without understanding the precise mechanism. The fresh insights gleaned from this study illuminated that irisin’s influence in this context is closely tied to the enhancement of an enzyme known as neprilysin, which is proficient in degrading amyloid-beta.
Se Hoon Choi, one of the study’s authors, illuminated that treating with irisin led to a “remarkable reduction of amyloid-beta pathology,” an effect steered by the bolstered activity of neprilysin, which is secreted in higher quantities by brain cells called astrocytes, in response to irisin.
Notably, the researchers managed to pinpoint the pathway that prompts cells to amplify neprilysin levels, opening avenues for further exploration and therapy development. The endeavour now stood grounded on a robust foundation of understanding how irisin, once introduced into the bloodstream, can navigate its way to the brain, showcasing its potential utility as a therapeutic agent.
Furthermore, senior author Rudolph Tanzi noted that irisin could be the principal orchestrator behind exercise-induced escalations in neprilysin levels that are instrumental in alleviating the amyloid-beta burden in the brain. Tanzi underscored the significant implications of these findings, propelling irisin to the centre stage as a promising target for preventive and therapeutic strategies against Alzheimer’s disease.
This groundbreaking study, published in the renowned journal Neuron on September 8 2023, brings to light irisin’s pivotal role as a mediator, leveraging the natural, exercise-induced hormone to forge a path towards revolutionary Alzheimer’s treatments. It brings us a step closer to harnessing the potential of physical exercise at a molecular level in battling the devastating impacts of Alzheimer’s, thus offering a new ray of hope in medical science’s quest to conquer this debilitating disease.