Hacker’s Vault


Review - Tissue stretch induces nuclear remodelling in connective tissue fibroblasts

Mechanical environment of the cell – stretching – has a profound influence on cell nucleus (Langevin et. Al, 2010).

Stretching of connective tissue for 30 minutes causes a change in the shape of fibroblast nuclei, which were wider, flatter and less concave (smoother).

The consequences of stretch-induced nuclear remodeling and loss of nuclear concavity are far reaching. Mounting evidence suggests that cell and nuclear shape can influence cell differentiation (change from one cell type to another), chromatin structure (DNA, RNA and Protein) and Histone Acetylation (alters accessibility of chromatin and allows DNA binding proteins to interact with exposed sites to active gene transcription and downstream cellular functions).

Direct transmission of forces through the cytoplasmic and nuclear cytoskeleton via changes in cell and nuclear shape has been proposed as a source of specific coupling between tissue mechanical forces (in-plane tensile forces: stretching – and/or perpendicular compressive forces, eg. Foam rolling) and the genome (all genetic material of an organism).

The change in nuclear shape and smoothing of the nuclear surface could result from direct viscoelastic deformation (the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation) – or could represent a more complex phenomenon involving active reorganization of nuclear structure in response to tissue stretch. Nuclear stiffness can continue to change over longer time scales in response to mechanical deformation and cytoskeletal remodeling has been suggested as a possible explanation for this type of biomechanical behavior.

Cytoskeletal remodeling – or actin remodeling – is the biomechanical process that allows for the dynamic alterations of cellular organization.

The delayed onset of the change in nuclear morphology (more than 2 minutes) and the persistence of morphological changes after the release of tissue stretch suggest that the changes in nuclear shape involve structural remodeling, rather than direct stretching or compression of the nuclei.

In response to tissue stretch, extensive cytoskeletal reorganization is taking place in response to tissue stretch.
Stretching of whole, subcutaneous tissue resulted in a change in fibroblast nuclear shape with a loss of nuclear concavity. These results indicate that the mechanical environment of the cell has a profound influence on the cell nucleus.

To put this in layman’s terms, stretching any muscle of the body results in a long term change in fibroblast cell size, shape and smoothness. Stretching of tissue also results in the reorganization of cells.

Flexibility and mobility training has profound effects at a cellular level. Science, baby!