Scanning Ion-Conductance Microscopy for Studying β-Amyloid Aggregate Formation on Living Cell Surfaces.

Area of Science:

• Neuroscience
• Biophysics
• Cell Biology

Background:

• Beta-amyloid (Aβ) aggregation on neuronal surfaces is implicated in neurodegenerative diseases.
• Aβ aggregation disrupts cellular functions via calcium influx, apoptosis, and reduced membrane potential.
• Cytoskeletal changes, particularly actin and microtubules, alter cell mechanical properties.

Purpose of the Study:

• To investigate the precise connection between Aβ aggregate formation on cell membranes and alterations in local cell mechanical properties.
• To explore the role of reactive oxygen species (ROS) in mediating Aβ-induced changes in cell mechanics.

Main Methods:

• Correlative scanning ion-conductance microscopy (SICM) for cell topography, Young's modulus mapping, and confocal imaging of Aβ aggregates.
• Measurement of intracellular reactive oxygen species (ROS) levels using platinum nanoelectrodes.

Main Results:

• SICM successfully mapped Aβ aggregate formation and correlated it with changes in cell Young's modulus.
• Aβ-induced oxidative stress and increased intracellular ROS levels were observed.
• A direct link between ROS levels and alterations in cellular Young's modulus was demonstrated.

Conclusions:

• Aβ aggregation on living cell surfaces significantly impacts cell mechanics.
• Reactive oxygen species play a crucial role in mediating the mechanical changes induced by Aβ.
• SICM is a valuable tool for studying the cytotoxicity mechanisms of Aβ aggregates.