Disruption of both nesprin 1 and desmin results in nuclear anchorage defects and fibrosis in skeletal muscle.

Abstract

Proper localization and anchorage of nuclei within skeletal muscle is critical for cellular function. Alterations in nuclear anchoring proteins modify a number of cellular functions including mechanotransduction, nuclear localization, chromatin positioning/compaction and overall organ function. In skeletal muscle, nesprin 1 and desmin are thought to link the nucleus to the cytoskeletal network. Thus, we hypothesize that both of these factors play a key role in skeletal muscle function. To examine this question, we utilized global ablation murine models of nesprin 1, desmin or both nesprin 1 and desmin. Herein, we have created the nesprin-desmin double-knockout (DKO) mouse, eliminating a major fraction of nuclear-cytoskeletal connections and enabling understanding of the importance of nuclear anchorage in skeletal muscle. Globally, DKO mice are marked by decreased lifespan, body weight and muscle strength. With regard to skeletal muscle, DKO myonuclear anchorage was dramatically decreased compared with wild-type, nesprin 1(-/-) and desmin(-/-) mice. Additionally, nuclear-cytoskeletal strain transmission was decreased in DKO skeletal muscle. Finally, loss of nuclear anchorage in DKO mice coincided with a fibrotic response as indicated by increased collagen and extracellular matrix deposition and increased passive mechanical properties of muscle bundles. Overall, our data demonstrate that nesprin 1 and desmin serve redundant roles in nuclear anchorage and that the loss of nuclear anchorage in skeletal muscle results in a pathological response characterized by increased tissue fibrosis and mechanical stiffness.

• Authors: Mark A Chapman, Jianlin Zhang, Indroneal Banerjee, Ling T Guo, Zhiwei Zhang, G Diane Shelton, Kunfu Ouyang, Richard L Lieber, Ju Chen
• Journal: Human molecular genetics (Hum Mol Genet) Vol. 23 Issue 22 Pg. 5879-92 (Nov 15 2014) ISSN: 1460-2083 [Electronic] England
• PMID: 24943590 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: [email protected].

Chemical References

• Cytoskeletal Proteins
• Desmin
• Nerve Tissue Proteins
• Nuclear Proteins
• Syne1 protein, mouse

Topics

• Animals
• Cell Nucleus (genetics, metabolism)
• Cytoskeletal Proteins
• Desmin (genetics, metabolism)
• Female
• Fibrosis (genetics, metabolism)
• Humans
• Male
• Mice
• Mice, Knockout
• Muscle, Skeletal (metabolism, pathology)
• Muscular Dystrophies (genetics, metabolism, pathology)
• Nerve Tissue Proteins (genetics, metabolism)
• Nuclear Proteins (genetics, metabolism)
• Protein Transport