In vivoassessment of mechanical properties during axolotl development and regeneration using confocal Brillouin microscopy

Abstract

In processes such as development and regeneration, where large cellular and tissue rearrangements occur, cell fate and behaviour are strongly influenced by tissue mechanics. While most well-established tools probing mechanical properties require an invasive sample preparation, confocal Brillouin microscopy captures mechanical parameters optically with high resolution in a contact-free and label-free fashion. In this work, we took advantage of this tool and the transparency of the highly regenerative axolotl to probe its mechanical properties in vivo for the first time. We mapped the Brillouin frequency shift with high resolution in developing limbs and regenerating digits, the most studied structures in the axolotl. We detected a gradual increase in the cartilage Brillouin frequency shift, suggesting decreasing tissue compressibility during both development and regeneration. Moreover, we were able to correlate such an increase with the regeneration stage, which was undetected with fluorescence microscopy imaging. The present work evidences the potential of Brillouin microscopy to unravel the mechanical changes occurring in vivo in axolotls, setting the basis to apply this technique in the growing field of epimorphic regeneration.

The salamander limb: a perfect model to understand imperfect integration during skeletal regeneration

“…two-photon microscopy) or grafting of new biomaterials. Recent works assessing tissue mechanical properties and pairing quantifications with predictive computational models ( Comellas et al, 2022 ; Kondiboyina et al, 2024 ; Riquelme-Guzmán et al, 2022b ) demonstrate their unique potential. We are hopeful the field will continue to move forward with studies tackling the most pressing issues.…”

2024: The quest continues

“…Since my last editorial, we have published our Special Issue on Quantitative imaging (https://royalsociety.org/blog/2023/12/open-biology-decoding-lifes-innerworkings/) guest edited by Ricardo Henriques, Christophe Leterrier and Aubrey Weigel that showcased the power of new forms of microscopy and image analysis to answer questions across the breadth of biological scales, ranging from super-resolution microscopy to map molecular complexes through probes to interrogate membrane properties [1], and from image analysis scripts to classify changes in the morphology of microglia [2], to the macroscale measurement of tissue mechanics in axolotl development [3]. This year we will address the scale of biological time and publish a Special Issue on Evolutionary Cell Biology of Microbial Eukaryotes, guest edited by Filip Husnik and Guatam Dey.…”