Heat shock proteins suppress amyloid-beta toxicity in the brain.
Amyloid-beta is a toxic peptide that aggregates and forms plaques in the brain with age. These plaques are widely considered a hallmark of Alzheimer’s disease, a progressive neurodegenerative disease that occurs with age and is the most common cause of dementia. Findings from a 2016 study suggest that heat shock proteins suppress amyloid-beta toxicity in the brain.
Heat-shock proteins comprise a large, highly conserved family of proteins that are present in all cells, across many species. They play prominent roles in many cellular processes and facilitate several aspects of the protein synthesis machinery, including assembly and folding. Increased expression of heat shock proteins prevents protein disorder and aggregation by repairing proteins that have been damaged or misfolded and may offer protection against neurodegenerative diseases and inhibit the aggregation of amyloid-beta, reducing plaque formation.
The study involved fruit flies, which serve as useful models for studying amyloid-beta anomalies. The investigators engineered a form of heat shock protein 70, called Hsp70, that could pass into the extracellular space and interact with amyloid-beta and studied its effects on the flies' neurological health.
They found that Hsp70 suppressed the toxicity of amyloid-beta in cells of the flies' eyes, reduced cell death in brain neurons, and helped maintain the neurons' architecture and function. The investigators posited that these neuroprotective effects were directly related to Hsp70’s capacity to bind to amyloid-beta rather than via refolding mechanisms.
These findings indicate that heat shock protein 70 may suppress amyloid-beta toxicity, thereby reducing amyloid-beta plaque formation in the brain and serving as a potential therapeutic strategy for Alzheimer’s disease. Heat stress, such as that experienced during sauna use, robustly induces expression of heat shock proteins. Learn more about heat shock proteins and sauna use in our overview article.