Tissue-specific mechanical and geometrical control of cell viability and actin cytoskeleton alignment

Wang, Dong; Zheng, Wenfu; Xie, Yunyan; Gong, Peiyuan; Zhao, Fang; Yuan, Bo; Ma, Wanshun; Cui, Yan; Liu, Wenwen; Sun, Yi; Piel, Matthieu; Zhang, Wei; Jiang, Xingyu

doi:10.1038/srep06160

Cited by 36 publications

(30 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The assembly of actin filaments into contractile stress fibers follows a mechanism common among adherent cell types (49), and actin stress fiber alignment is also seen in other cell types patterned into rectangular shapes (26,50,51). Nonmuscle actin stress fibers have several homologies with their myofibril isoforms in contractility, organization, and composition (49,52,53).…”

Section: Discussionmentioning

confidence: 99%

Contractility of single cardiomyocytes differentiated from pluripotent stem cells depends on physiological shape and substrate stiffness

Ribeiro

Ang

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

404

456

View full text Add to dashboard Cite

Single cardiomyocytes contain myofibrils that harbor the sarcomerebased contractile machinery of the myocardium. Cardiomyocytes differentiated from human pluripotent stem cells (hPSC-CMs) have potential as an in vitro model of heart activity. However, their fetallike misalignment of myofibrils limits their usefulness for modeling contractile activity. We analyzed the effects of cell shape and substrate stiffness on the shortening and movement of labeled sarcomeres and the translation of sarcomere activity to mechanical output (contractility) in live engineered hPSC-CMs. Single hPSC-CMs were cultured on polyacrylamide substrates of physiological stiffness (10 kPa), and Matrigel micropatterns were used to generate physiological shapes (2,000-μm 2 rectangles with length:width aspect ratios of 5:1-7:1) and a mature alignment of myofibrils. Translation of sarcomere shortening to mechanical output was highest in 7:1 hPSC-CMs. Increased substrate stiffness and applied overstretch induced myofibril defects in 7:1 hPSC-CMs and decreased mechanical output. Inhibitors of nonmuscle myosin activity repressed the assembly of myofibrils, showing that subcellular tension drives the improved contractile activity in these engineered hPSC-CMs. Other factors associated with improved contractility were axially directed calcium flow, systematic mitochondrial distribution, more mature electrophysiology, and evidence of transverse-tubule formation. These findings support the potential of these engineered hPSC-CMs as powerful models for studying myocardial contractility at the cellular level.contractility | sarcomeres | cardiomyocyte | stem cell | single cell

show abstract

Section: Discussionmentioning

confidence: 99%

Contractility of single cardiomyocytes differentiated from pluripotent stem cells depends on physiological shape and substrate stiffness

Ribeiro

Ang

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

404

456

View full text Add to dashboard Cite

show abstract

“…[23] However, prior studies have focused predominantly on 2D patterns or the study of single cells in confined spaces, [11, 24, 25] and only recently have 3D patterned wells and surfaces started to be explored to investigate the collective behavior of cells. [26, 27] In our work, we utilized soft-lithographic techniques to address a fundamental question in cell biology: How does anisotropy alter the cell behavior of cell populations and their generated matrix in 3D anisotropic spaces?…”

Section: Discussionmentioning

confidence: 99%

Patterning of Fibroblast and Matrix Anisotropy within 3D Confinement is Driven by the Cytoskeleton

Serbo

Kuo

Lewis

et al. 2015

Adv Healthcare Materials

View full text Add to dashboard Cite

Effects of 3D confinement on cellular growth and matrix assembly are important in tissue engineering, developmental biology, and regenerative medicine. Polydimethylsiloxane wells with varying anisotropy are microfabicated using soft‐lithography. Microcontact printing of bovine serum albumin is used to block cell adhesion to surfaces between wells. The orientations of fibroblast stress fibers, microtubules, and fibronectin fibrils are examined 1 day after cell seeding using laser scanning confocal microscopy, and anisotropy is quantified using a custom autocorrelation analysis. Actin, microtubules, and fibronectin exhibit higher anisotropy coefficients for cells grown in rectangular wells with aspect ratios of 1:4 and 1:8, as compared to those in wells with lower aspect ratios or in square wells. The effects of disabling individual cytoskeletal components on fibroblast responses to anisotropy are then tested by applying actin or microtubule polymerization inhibitors, Rho kinase inhibitor, or by siRNA‐mediated knockdown of AXL or cofilin‐1. Latrunculin A decreases cytoskeletal and matrix anisotropy, nocodazole ablates both, and Y27632 mutes cellular polarity while decreasing matrix anisotropy. AXL siRNA knockdown has little effect, as does siRNA knockdown of cofilin‐1. These data identify several specific cytoskeletal strategies as targets for the manipulation of anisotropy in 3D tissue constructs.

show abstract

“…Recent studies have revealed that cytoskeletal organization and nuclear morphology are regulated by extracellular mechanical signals, such as substrate stiffness and geometry (32)(33)(34)(35)(36)(37)(38)(39)(40)(41). With the cytoskeleton physically linked to the nucleoskeleton, these extracellular mechanical signals can therefore be used to mediate changes in chromatin structure.…”

mentioning

confidence: 99%

Nuclear deformability and telomere dynamics are regulated by cell geometric constraints

Makhija

Jokhun

Shivashankar

2015

Proc. Natl. Acad. Sci. U.S.A.

189

186

View full text Add to dashboard Cite

Forces generated by the cytoskeleton can be transmitted to the nucleus and chromatin via physical links on the nuclear envelope and the lamin meshwork. Although the role of these active forces in modulating prestressed nuclear morphology has been well studied, the effect on nuclear and chromatin dynamics remains to be explored. To understand the regulation of nuclear deformability by these active forces, we created different cytoskeletal states in mouse fibroblasts using micropatterned substrates. We observed that constrained and isotropic cells, which lack long actin stress fibers, have more deformable nuclei than elongated and polarized cells. This nuclear deformability altered in response to actin, myosin, formin perturbations, or a transcriptional down-regulation of lamin A/C levels in the constrained and isotropic geometry. Furthermore, to probe the effect of active cytoskeletal forces on chromatin dynamics, we tracked the spatiotemporal dynamics of heterochromatin foci and telomeres. We observed increased dynamics and decreased correlation of the heterochromatin foci and telomere trajectories in constrained and isotropic cell geometry. The observed enhanced dynamics upon treatment with actin depolymerizing reagents in elongated and polarized geometry were regained once the reagent was washed off, suggesting an inherent structural memory in chromatin organization. We conclude that active forces from the cytoskeleton and rigidity from lamin A/C nucleoskeleton can together regulate nuclear and chromatin dynamics. Because chromatin remodeling is a necessary step in transcription control and its memory, genome integrity, and cellular deformability during migration, our results highlight the importance of cell geometric constraints as critical regulators in cell behavior. mechanotransduction | cell geometry | actomyosin contractility | chromatin dynamics | telomere dynamics P hysical properties of the nucleus, such as its morphology and deformability, have been associated with important cellular functions like gene expression, genome integrity, and cell behavior (1-3). The major cellular components that regulate these physical properties are the cytoskeleton to nuclear links and the nuclear lamina (4-8). Lineage-specific physical properties of the nucleus emerge during cellular differentiation; although stem cell nuclei are highly deformable (9, 10) and have a dynamic chromatin with hyperdynamic chromatin proteins (11), with differentiation, nuclei lose their deformability and become less deformable (12). The nucleus in a differentiated cell is physically coupled to the cytoskeleton via lamins and the linker of nucleoskeleton and cytoskeleton (LINC) complex, which comprises transmembrane Sad1p, UNC-84 (SUN) and Klarsicht, ANC-1, Syne Homology (KASH) domain proteins (13-18). Any perturbation to these components is linked to changes in nuclear morphology and deformability (19). Therefore, the meshwork of actin stress fibers and lamin A/C serves as a critical physical intermediate in the maintenance of nuclear func...

show abstract

Tissue-specific mechanical and geometrical control of cell viability and actin cytoskeleton alignment

Cited by 36 publications

References 44 publications

Contractility of single cardiomyocytes differentiated from pluripotent stem cells depends on physiological shape and substrate stiffness

Contractility of single cardiomyocytes differentiated from pluripotent stem cells depends on physiological shape and substrate stiffness

Patterning of Fibroblast and Matrix Anisotropy within 3D Confinement is Driven by the Cytoskeleton

Nuclear deformability and telomere dynamics are regulated by cell geometric constraints

Contact Info

Product

Resources

About