Intracellular Aβ42 Aggregation Leads to Cellular Thermogenesis.

Area of Science:

• Biochemistry
• Cell Biology
• Neuroscience

Background:

• Amyloid beta (Aβ42) aggregation is a key feature of Alzheimer's disease (AD).
• The intracellular biochemical changes driving Aβ42 aggregation remain unclear.
• Cellular stress and thermogenesis are potentially linked to protein aggregation.

Purpose of the Study:

• To investigate the relationship between Aβ42 aggregation and intracellular temperature changes.
• To explore the potential of using thermometry for screening AD therapeutic candidates.
• To elucidate the biophysical factors influencing heat retention in Aβ peptides.

Main Methods:

• Intracellular thermometry using fluorescent polymeric thermometers in live cells.
• Treatment with Aβ42 aggregation inhibitors.
• Classical molecular dynamics simulations of model Aβ peptides.

Main Results:

• Aβ42 aggregation in cells causes a measurable increase in average intracellular temperature.
• This temperature rise is reduced by Aβ42 aggregation inhibitors.
• Molecular dynamics revealed that ions, peptide morphology, and water interactions influence Aβ heat retention.

Conclusions:

• Aβ42 aggregation contributes to cellular thermogenesis, independent of mitochondrial damage.
• Intracellular ionic conditions can promote Aβ aggregation and heat retention, potentially accelerating AD progression.
• The study presents a novel diagnostic assay for screening small-molecule inhibitors against amyloid aggregation in relevant cellular environments.