LIU, Liwang; SIMON, Marina; MUGGIOLU, Giovanna; VILOTTE, Florent; ANTOINE, Mikael; CARON, Jerôme; KANTOR, Guy; BARBERET, Philippe; SEZNEC, Hervé; AUDOIN, Bertrand

doi:10.1016/j.pacs.2022.100385

Langue

Article de revue

Ce document a été publié dans

Photoacoustics. 2022-07-11, vol. 27, p. 100385

Résumé en anglais

How DNA damage and repair processes affect the biomechanical properties of the nucleus interior remains unknown. Here, an opto-acoustic microscope based on time-domain Brillouin spectroscopy (TDBS) was used to investigate the induced regulation of intra-nuclear mechanics. With this ultrafast pump-probe technique, coherent acoustic phonons were tracked along their propagation in the intra-nucleus nanostructure and the complex stiffness moduli and thicknesses were measured with an optical resolution. Osteosarcoma cells were exposed to methyl methanesulfonate (MMS) and the presence of DNA damage was tested using immunodetection targeted against damage signaling proteins. TDBS revealed that the intra-nuclear storage modulus decreased significantly upon exposure to MMS, as a result of the chromatin decondensation and reorganization that favors molecular diffusion within the organelle. When the damaging agent was removed and cells incubated for 2 h in the buffer solution before fixation the intra-nuclear reorganization led to an inverse evolution of the storage modulus, the nucleus stiffened. The same tendency was measured when DNA double-strand breaks were caused by cell exposure to ionizing radiation. TDBS microscopy also revealed changes in acoustic dissipation, another mechanical probe of the intra-nucleus organization at the nano-scale, and changes in nucleus thickness during exposure to MMS and after recovery.< Réduire

Mots clés en anglais

DNA damage/repair

Chromatin condensation/decondensation

Molecular clustering

Nuclear mechanics

Coherent phonon spectroscopy

Picosecond ultrasonics

Ultrafast opto-acoustics

URI

https://oskar-bordeaux.fr/handle/20.500.12278/170311

DOI

http://dx.doi.org/10.1016/j.pacs.2022.100385

Project ANR

Echographie opto-acoustique de cellules individuelles ex vivo - ANR-17-CE11-0020

Unités de recherche

Institut de Mécanique et d’Ingénierie de Bordeaux (I2M) - UMR 5295

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Changes in intra-nuclear mechanics in response to DNA damaging agents revealed by time-domain Brillouin micro-spectroscopy