The mechanobiology of nuclear phase separation

APL Bioengineering, Journal Year: 2022, Volume and Issue: 6(2)

Published: April 28, 2022

The cell nucleus can be thought of as a complex, dynamic, living material, which functions to organize and protect the genome coordinate gene expression. These are achieved via intricate mechanical biochemical interactions among its myriad components, including nuclear lamina, bodies, chromatin itself. While biophysical organization lamina have been thoroughly studied, concept that liquid-liquid phase separation related transitions play role in establishing structure has emerged only recently. Phase likely intimately coupled mechanobiology structural elements nucleus, but their interplay with one another is still not understood. Here, we review recent developments on mechanics discuss functional implications physiology disease states.

Language: Английский

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Peripheral heterochromatin tethering is required for chromatin-based nuclear mechanical response

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 16, 2025

The cell nucleus is a mechanically responsive structure that governs how external forces affect chromosomes. Chromatin, particularly transcriptionally inactive heterochromatin, resists nuclear deformations through its mechanical response. However, chromatin also exhibits liquid-like properties, casting ambiguity on the physical mechanisms of chromatin-based elasticity. To determine heterochromatin strengthens response, we performed polymer physics simulations model validated by micromechanical measurements and chromosome conformation capture data. attachment peripheral to lamina required transmit directly elicit elastic Thus, increases in levels increase rigidity increasing linkages between lamina. Crosslinks within such as HP1 α proteins, can stiffen nuclei, but only if peripherally tethered. In contrast, affinity interactions may drive liquid-liquid phase separation do not contribute rigidity. When stretched, gel-like bear stresses deform, while more fluid-like interior euchromatin less perturbed. heterochromatin's internal stiffness regulate mechanics via lamina, enabling mechanosensing measurement nucleus' architecture.

Language: Английский

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The viscoelastic properties of Nicotiana tabacum BY-2 suspension cell lines adapted to high osmolarity

BMC Plant Biology, Journal Year: 2025, Volume and Issue: 25(1)

Published: Feb. 25, 2025

Abstract To survive and grow, plant cells must regulate the properties of their cellular microenvironment in response to ever changing external factors. How biomechanical balance across cell’s internal structures is established maintained during environmental variations remains a nurturing question. provide insight into this issue we used two micro-mechanical imaging techniques, namely Brillouin light scattering BODIPY-based molecular rotors Fluorescence Lifetime Imaging, study Nicotiana tabacum suspension BY-2 long-term adapted high concentrations NaCl mannitol. The crowding cytoplasm vacuoles was examined, as well tension plasma membrane. understand how sudden changes osmolarity affect mechanics, control already further short-term osmotic stimulus also examined. viscoelasticity protoplasts altered differently adaptation processes compared responses hyperosmolarity stress. applied correlative approach provides evidence that hyperosmotic stress leads different ratios protoplast qualities help maintain cell integrity. viscoelastic are an element osmolarity. Moreover, such has impact on Graphical

Language: Английский

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The mechanobiology of biomolecular condensates

Biophysics Reviews, Journal Year: 2025, Volume and Issue: 6(1)

Published: March 1, 2025

The central goal of mechanobiology is to understand how the mechanical forces and material properties organelles, cells, tissues influence biological processes functions. Since first description biomolecular condensates, it was hypothesized that they obtain are tuned their functions inside cells. Thus, represent an intriguing playground for mechanobiology. idea condensates exhibit diverse adaptive highlights need different states respond external whether these responses linked physiological roles within cell. For example, liquids buffer dissipate, while solids store transmit stress, relaxation time a viscoelastic can act as frequency filter. Hence, liquid-solid transition condensate in force transmission pathway determine signals transduced in-between affecting differentiation, neuronal network dynamics, behavior stimuli. Here, we review our current understanding molecular drivers rigidity phase transitions set forth complex cellular environment. We will then summarize technical advancements were necessary insights into rich fascinating finally, highlight recent examples connection specific Our provide comprehensive summary field on cells harness regulate mechanics achieve

Language: Английский

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Axisymmetric thermoviscous and thermal expansion flows for microfluidics

Journal of Engineering Mathematics, Journal Year: 2025, Volume and Issue: 152(1)

Published: April 25, 2025

Abstract Recent microfluidic experiments have explored the precise positioning of micron-sized particles in liquid environments via laser-induced thermoviscous flow. From micro-robotics to biology at subcellular scale, this versatile technique has found a broad range applications. Through interplay between thermal expansion and viscosity changes, repeated scanning laser along scan path results fluid flow hence net transport particles, without physical channels. Building on previous work focusing two-dimensional settings, we present an analytical, theoretical model for flows induced by translating heat spot three-dimensional, unconfined fluid. We first numerically solve temperature field due source experimentally relevant limit. Then, our model, small, localised increase causes local changes mass density, shear bulk derive analytically instantaneous generated during one compute passive tracers full scan, up quadratic order coefficients. further show that are independent viscosity. In far field, while leading-order is typically three-dimensional or sink, average velocity instead dipole, whose strength depends relative magnitudes Our quantitative reveal potential future manipulation microscale.

Language: Английский

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Chromatin compaction during confined cell migration induces and reshapes nuclear condensates

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Nov. 18, 2024

Abstract Cell migration through small constrictions during cancer metastasis requires significant deformation of the nucleus, with associated mechanical stress on nuclear lamina and chromatin. However, how impacts various subnuclear structures, including protein nucleic acid-rich biomolecular condensates, is largely unknown. Here, we find that cell confined spaces gives rise to deformations chromatin network, which cause embedded nucleoli speckles, deform coalesce. Chromatin exhibit differential behavior in advancing vs. trailing region half being more permissive for de novo condensate formation. We show this results from increased heterogeneity, a shift binodal phase boundary. Taken together, our findings assembly properties, can potentially contribute cellular mechanosensing.

Language: Английский

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Interphase chromatin biophysics and mechanics: new perspectives and open questions

Current Opinion in Genetics & Development, Journal Year: 2024, Volume and Issue: 90, P. 102296 - 102296

Published: Dec. 25, 2024

Language: Английский

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Appetizer on soft matter physics concepts in mechanobiology

Development Growth & Differentiation, Journal Year: 2023, Volume and Issue: 65(5), P. 234 - 244

Published: May 1, 2023

Mechanosensing, the active responses of cells to mechanics on multiple scales, plays an indispensable role in regulating cell behaviors and determining fate biological entities such as tissues organs. Here, I aim give a pedagogical illustration fundamental concepts soft matter physics that aid understanding biomechanical phenomena from scale proteins. Examples up-to-date research are introduced elaborate these concepts. Challenges applying models biology have also been discussed for biologists physicists meet field mechanobiology.

Language: Английский

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Chromatin condensed domains revealed by AFM, and their transformation in mechanically deformed normal and malignant cell nuclei.

Biochemical and Biophysical Research Communications, Journal Year: 2024, Volume and Issue: 736, P. 150861 - 150861

Published: Oct. 23, 2024

Language: Английский

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The viscoelastic properties ofNicotiana tabacumBY-2 suspension cell lines adapted to high osmolarity

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 30, 2024

Abstract To survive and grow, plant cells must regulate the properties of their cellular microenvironment in response to ever changing external factors. How biomechanical balance across cell’s internal structures is established maintained during environmental variations remains a nurturing question. provide insight into this issue we used two micro-mechanical imaging techniques, namely Brillouin light scattering BODIPY-based molecular rotors Fluorescence Lifetime Imaging, study Nicotiana tabacum suspension BY-2 long-term adapted high concentrations NaCl mannitol. We discuss our results terms crowding cytoplasm vacuoles, as well tension plasma membrane. The viscoelastic behavior was elucidated relative environments revealing difference between responses vacuole cells. understand how sudden changes osmolarity affect mechanics, control already further short-term osmotic stimulus also examined. applied correlative approach provides evidence that adaptation hyperosmotic stress leads different ratios protoplast qualities help maintain cell integrity. Presented demonstrate protoplasts are an element osmolarity.

Language: Английский

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