Membrane fluctuations of human red blood cells investigated by the current signal noise in scanning ion conductance microscopy

Year: 2024

Authors: Pellegrino M., Orsini P., Tognoni E.

Autors Affiliation: CNR, INO, Via Moruzzi 1, I-56124 Pisa, Italy; Univ Pisa, Dipartimento Ric Traslaz & Nuove Tecnol Med & Chir, Via S Zeno 31, I-56127 Pisa, Italy.

Abstract: Human red blood cells show submicron membrane fluctuations (CMFs) that have been mainly studied with optical microscopies. Although the functional role of this phenomenon is still uncertain, the amplitude of membrane fluctuations is considered as an indicator of mechanical resilience to the stress encountered in the capillary beds. We investigate here the membrane fluctuations in red blood cells using the scanning ion conductance microscopy (SICM), a scanning probe technique that avoids the probe-sample contact. The ion current noise was recorded at a fixed distance from the cell and converted in terms of membrane fluctuation amplitude using as a converting factor the slope of the current-distance curve. We found that CMF amplitude was irreversibly reduced by membrane cross -link. Both whole cell and local increase of membrane tension induced a reduction of CMF amplitude. As for the biochemical regulation of membrane dynamics, we observed that the activation of the noradrenergic transduction pathway, via beta -receptors, increased the CMF amplitude. We conclude that the CMFs recorded by SICM and those optically recorded on red blood cells share the main features. In addition SICM provides high spatial and temporal resolution as well as the possibility to apply through the glass pipette acting as probe chemical or physical stimuli to the membrane area where the CMFs are recorded.

Journal/Review: MICRON

Volume: 181      Pages from: 103635-1  to: 103635-7

More Information: This work was partially funded under the National Recovery and Resilience Plan (NRRP) , Mission 4 Component 2 Investment 1.4-Call for tender No. 3277 of 30 December 2021 of Italian Ministry of University and Research funded by the European Union – NextGenerationEU.r tender No. 3277 of 30 December 2021 of Italian Ministry of University and Research funded by the European Union – NextGenerationEU.
KeyWords: Red blood cells; Membrane fluctuations; Scanning ion conductance microscopy; Noise
DOI: 10.1016/j.micron.2024.103635


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