Nuclear decoupling is part of a rapid protein-level cellular response to high-intensity mechanical loading

Nat Commun. 2019 Sep 12;10(1):4149. doi: 10.1038/s41467-019-11923-1.

Abstract

Studies of cellular mechano-signaling have often utilized static models that do not fully replicate the dynamics of living tissues. Here, we examine the time-dependent response of primary human mesenchymal stem cells (hMSCs) to cyclic tensile strain (CTS). At low-intensity strain (1 h, 4% CTS at 1 Hz), cell characteristics mimic responses to increased substrate stiffness. As the strain regime is intensified (frequency increased to 5 Hz), we characterize rapid establishment of a broad, structured and reversible protein-level response, even as transcription is apparently downregulated. Protein abundance is quantified coincident with changes to protein conformation and post-translational modification (PTM). Furthermore, we characterize changes to the linker of nucleoskeleton and cytoskeleton (LINC) complex that bridges the nuclear envelope, and specifically to levels and PTMs of Sad1/UNC-84 (SUN) domain-containing protein 2 (SUN2). The result of this regulation is to decouple mechano-transmission between the cytoskeleton and the nucleus, thus conferring protection to chromatin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Biomechanical Phenomena
  • Cell Nucleus / metabolism*
  • Cell Nucleus Shape
  • Chromatin / metabolism
  • Cytoskeleton / metabolism
  • DNA Damage
  • Histones / metabolism
  • Humans
  • Ion Channels / metabolism
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism
  • Models, Biological
  • Nuclear Envelope / metabolism
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / metabolism*
  • Protein Domains
  • Protein Processing, Post-Translational
  • Proteome / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Stress, Mechanical
  • Tensile Strength

Substances

  • Chromatin
  • H2AX protein, human
  • Histones
  • Ion Channels
  • Nuclear Proteins
  • Proteome
  • RNA, Messenger