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Danielsson BE, Tieu KV, Bathula K, Armiger TJ, Vellala PS, Taylor RE, Dahl KN, Conway DE. Lamin microaggregates lead to altered mechanotransmission in progerin-expressing cells. Nucleus 2021; 11:194-204. [PMID: 32816594 PMCID: PMC7529416 DOI: 10.1080/19491034.2020.1802906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The nuclear lamina is a meshwork of intermediate filament proteins, and lamin A is the primary mechanical protein. An altered splicing of lamin A, known as progerin, causes the disease Hutchinson-Gilford progeria syndrome. Progerin-expressing cells have altered nuclear shapes and stiffened nuclear lamina with microaggregates of progerin. Here, progerin microaggregate inclusions in the lamina are shown to lead to cellular and multicellular dysfunction. We show with Comsol simulations that stiffened inclusions causes redistribution of normally homogeneous forces, and this redistribution is dependent on the stiffness difference and relatively independent of inclusion size. We also show mechanotransmission changes associated with progerin expression in cells under confinement and cells under external forces. Endothelial cells expressing progerin do not align properly with patterning. Fibroblasts expressing progerin do not align properly to applied cyclic force. Combined, these studies show that altered nuclear lamina mechanics and microstructure impacts cytoskeletal force transmission through the cell.
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Affiliation(s)
- Brooke E Danielsson
- Department of Biomedical Engineering, Virginia Commonwealth University , Richmond, VA, USA
| | - Katie V Tieu
- Department of Biomedical Engineering, Virginia Commonwealth University , Richmond, VA, USA
| | - Kranthidhar Bathula
- Department of Biomedical Engineering, Virginia Commonwealth University , Richmond, VA, USA
| | - Travis J Armiger
- Chemical Engineering, Carnegie Mellon University , Pittsburgh, PA, USA
| | - Pragna S Vellala
- Department of Biomedical Engineering, Carnegie Mellon University , Pittsburgh, PA , USA
| | - Rebecca E Taylor
- Department of Biomedical Engineering, Carnegie Mellon University , Pittsburgh, PA , USA.,Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, PA, USA
| | - Kris Noel Dahl
- Chemical Engineering, Carnegie Mellon University , Pittsburgh, PA, USA.,Department of Biomedical Engineering, Carnegie Mellon University , Pittsburgh, PA , USA
| | - Daniel E Conway
- Department of Biomedical Engineering, Virginia Commonwealth University , Richmond, VA, USA
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Armiger TJ, Spagnol ST, Dahl KN. Nuclear mechanical resilience but not stiffness is modulated by αII-spectrin. J Biomech 2016; 49:3983-3989. [PMID: 27836504 DOI: 10.1016/j.jbiomech.2016.10.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/18/2016] [Accepted: 10/21/2016] [Indexed: 11/18/2022]
Abstract
Spectrins are multi-domain, elastic proteins that provide elasticity to the plasma membrane of erythrocytes and select nucleated cells. Spectrins have also been found in the nucleus of non-erythrocytes, but their function remains to be uncovered. It has been hypothesized that a spring-like spectrin network exists within the lamina nucleoskeleton, however, experiments testing a spectrin network׳s mechanical impact on the nucleus are lacking. Here, we knock-down levels of nuclear αII-spectrin with the goal of disrupting this nucleoskeletal spectrin network. We mechanically test live cells with intranuclear particle tracking and compression assays to probe changes in nuclear mechanics with decreases in αII-spectrin. We show no changes in chromatin mechanics or in the stiffness of nuclei under compression. However, we do observe a reduction in the ability of nuclei with decreased αII-spectrin to recover after compression. These results establish spectrin as a nucleoskeletal component that specifically contributes to elastic recovery after compression.
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Affiliation(s)
- Travis J Armiger
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Stephen T Spagnol
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Kris Noel Dahl
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA; Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
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