Indentation induces instantaneous nuclear stiffening and unfolding of nuclear envelope wrinkles.
Proc Natl Acad Sci U S A
; 120(36): e2307356120, 2023 09 05.
Article
in En
| MEDLINE
| ID: mdl-37639585
ABSTRACT
The nuclear envelope (NE) separates genomic DNA from the cytoplasm and regulates transport between the cytosol and the nucleus in eukaryotes. Nuclear stiffening enables the cell nucleus to protect itself from extensive deformation, loss of NE integrity, and genome instability. It is known that the reorganization of actin, lamin, and chromatin can contribute to nuclear stiffening. In this work, we show that structural alteration of NE also contributes to instantaneous nuclear stiffening under indentation. In situ mechanical characterization of cell nuclei in intact cells shows that nuclear stiffening and unfolding of NE wrinkles occur simultaneously at the indentation site. A positive correlation between the initial state of NE wrinkles, the unfolding of NE wrinkles, and the stiffening ratio (stiffness fold-change) is found. Additionally, NE wrinkles unfold throughout the nucleus outside the indentation site. Finite element simulation, which involves the purely passive process of structural unfolding, shows that unfolding of NE wrinkles alone can lead to an increase in nuclear stiffness and a reduction in stress and strain levels. Together, these results provide a perspective on how cell nucleus adapts to mechanical stimuli through structural alteration of the NE.
Key words
Full text:
1
Database:
MEDLINE
Main subject:
Cell Nucleus
/
Nuclear Envelope
Language:
En
Journal:
Proc Natl Acad Sci U S A
Year:
2023
Type:
Article
Affiliation country:
Canada