Hierarchical phase transitions as mechanical checkpoints of intracellular organization

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ueda, Yuika, Deguchi, Shinji
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911599368863744
author Ueda, Yuika
Deguchi, Shinji
author_facet Ueda, Yuika
Deguchi, Shinji
contents Living cells inherently reorganize their intracellular structures in response to mechanical cues from their environment. Among these responses, the formation of actin-based stress fibers exhibits a series of structural transitions depending on substrate stiffness: from disordered states on soft substrates, to partial alignment, and eventually to bundled formations as stiffness increases. While these transformations have been well documented in many cell types, the physical principles underlying their emergence remain elusive. Here, we observe identical stiffness-dependent actin reorganizations in senescent fibroblasts despite their diminished biochemical and metabolic activities, suggesting that physical constraints play a dominant role in the phenomenon. We then develop a statistical-mechanical framework to demonstrate that these changes arise through a hierarchy of threshold-dependent phase transitions dictated by energy-entropy competition. This formulation provides a thermodynamic basis for understanding how distinct cytoskeletal orders become favored under different mechanical regimes. We propose that these transitions serve as mechanical checkpoints that coordinate intracellular organization during G1-phase spreading. These findings reveal how mechanical cues guide distinct intracellular orders through a physically constrained hierarchy of transitions.
format Preprint
id arxiv_https___arxiv_org_abs_2408_14242
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Hierarchical phase transitions as mechanical checkpoints of intracellular organization
Ueda, Yuika
Deguchi, Shinji
Cell Behavior
Molecular Networks
Subcellular Processes
Living cells inherently reorganize their intracellular structures in response to mechanical cues from their environment. Among these responses, the formation of actin-based stress fibers exhibits a series of structural transitions depending on substrate stiffness: from disordered states on soft substrates, to partial alignment, and eventually to bundled formations as stiffness increases. While these transformations have been well documented in many cell types, the physical principles underlying their emergence remain elusive. Here, we observe identical stiffness-dependent actin reorganizations in senescent fibroblasts despite their diminished biochemical and metabolic activities, suggesting that physical constraints play a dominant role in the phenomenon. We then develop a statistical-mechanical framework to demonstrate that these changes arise through a hierarchy of threshold-dependent phase transitions dictated by energy-entropy competition. This formulation provides a thermodynamic basis for understanding how distinct cytoskeletal orders become favored under different mechanical regimes. We propose that these transitions serve as mechanical checkpoints that coordinate intracellular organization during G1-phase spreading. These findings reveal how mechanical cues guide distinct intracellular orders through a physically constrained hierarchy of transitions.
title Hierarchical phase transitions as mechanical checkpoints of intracellular organization
topic Cell Behavior
Molecular Networks
Subcellular Processes
url https://arxiv.org/abs/2408.14242