1
|
Cohen T, Zemmour C, Cohen OT, Benny O. Elongated Particles Show a Preferential Uptake in Invasive Cancer Cells. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1891. [PMID: 39683280 DOI: 10.3390/nano14231891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2024] [Revised: 11/14/2024] [Accepted: 11/22/2024] [Indexed: 12/18/2024]
Abstract
Mechanically driven cellular preference for drug carriers can enhance selectivity in cancer therapy, underscoring the importance of understanding the physical aspects of particle uptake. In this study, it was hypothesized that elongated particles might be preferentially taken up by deformable, aggressive cancer cells compared to normal cells. Two film-stretching methods were tested for 0.8-2.4 μm polystyrene (PS) particles: one based on solubility in organic solvents and the other on heat-induced softening. The heat-induced method produced more homogenous particle batches, with a standard deviation in the particle aspect ratio of 0.42 compared to 0.91 in the solvent-based method. The ability of cells to engulf elongated PS particles versus spherical particles was assessed in two subsets of human melanoma A375 cells. In the more aggressive cancer cell subset (A375+), uptake of elongated PS particles increased by 10% compared to spherical particles. In contrast, the less aggressive subset (A375-) showed a 25% decrease in uptake of elongated particles. This resulted in an uptake ratio between A375+ and A375- that was 1.5 times higher for elongated PS particles than for spherical ones. To further demonstrate relevance to drug delivery, elongated paclitaxel-loaded biodegradable, slow-releasing poly(lactic-co-glycolic) acid (PLGA) particles were synthesized. No significant difference in cytotoxic effect was observed between A375+ and A375- cells treated with spherical drug-loaded particles. However, treatment with ellipsoidal particles led to a significantly enhanced cytotoxic effect in aggressive cells compared to less aggressive cells. These findings present promising directions for tailored cancer drug delivery and demonstrate the importance of particle physical properties in cellular uptake and drug delivery mechanisms.
Collapse
Affiliation(s)
- Talya Cohen
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Chalom Zemmour
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Ora T Cohen
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Ofra Benny
- Institute for Drug Research, The School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| |
Collapse
|
2
|
Marshall-Burghardt S, Migueles-Ramírez RA, Lin Q, El Baba N, Saada R, Umar M, Mavalwala K, Hayer A. Excitable Rho dynamics control cell shape and motility by sequentially activating ERM proteins and actomyosin contractility. SCIENCE ADVANCES 2024; 10:eadn6858. [PMID: 39241071 PMCID: PMC11378911 DOI: 10.1126/sciadv.adn6858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 07/31/2024] [Indexed: 09/08/2024]
Abstract
Migration of endothelial and many other cells requires spatiotemporal regulation of protrusive and contractile cytoskeletal rearrangements that drive local cell shape changes. Unexpectedly, the small GTPase Rho, a crucial regulator of cell movement, has been reported to be active in both local cell protrusions and retractions, raising the question of how Rho activity can coordinate cell migration. Here, we show that Rho activity is absent in local protrusions and active during retractions. During retractions, Rho rapidly activated ezrin-radixin-moesin proteins (ERMs) to increase actin-membrane attachment, and, with a delay, nonmuscle myosin 2 (NM2). Rho activity was excitable, with NM2 acting as a slow negative feedback regulator. Strikingly, inhibition of SLK/LOK kinases, through which Rho activates ERMs, caused elongated cell morphologies, impaired Rho-induced cell contractions, and reverted Rho-induced blebbing. Together, our study demonstrates that Rho activity drives retractions by sequentially enhancing ERM-mediated actin-membrane attachment for force transmission and NM2-dependent contractility.
Collapse
Affiliation(s)
- Seph Marshall-Burghardt
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
- Graduate Program in Biology, McGill University, Montréal, Québec, Canada
| | - Rodrigo A Migueles-Ramírez
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
- PhD Program in Quantitative Life Sciences, McGill University, Montréal, Québec, Canada
| | - Qiyao Lin
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
- Graduate Program in Biology, McGill University, Montréal, Québec, Canada
| | - Nada El Baba
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
- Graduate Program in Biology, McGill University, Montréal, Québec, Canada
| | - Rayan Saada
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Mustakim Umar
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Kian Mavalwala
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Arnold Hayer
- Department of Biology, Stewart Biology Building, McGill University, Montréal, Québec H3A 1B1, Canada
| |
Collapse
|
3
|
Dutta S, Muraganadan T, Vasudevan M. Evaluation of lamin A/C mechanotransduction under different surface topography in LMNA related muscular dystrophy. Cytoskeleton (Hoboken) 2024. [PMID: 39091017 DOI: 10.1002/cm.21895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 08/04/2024]
Abstract
Most of the single point mutations of the LMNA gene are associated with distinct muscular dystrophies, marked by heterogenous phenotypes but primarily the loss and symmetric weakness of skeletal muscle tissue. The molecular mechanism and phenotype-genotype relationships in these muscular dystrophies are poorly understood. An effort has been here to delineating the adaptation of mechanical inputs into biological response by mutant cells of lamin A associated muscular dystrophy. In this study, we implement engineered smooth and pattern surfaces of particular young modulus to mimic muscle physiological range. Using fluorescence and atomic force microscopy, we present distinct architecture of the actin filament along with abnormally distorted cell and nuclear shape in mutants, which showed a tendency to deviate from wild type cells. Topographic features of pattern surface antagonize the binding of the cell with it. Correspondingly, from the analysis of genome wide expression data in wild type and mutant cells, we report differential expression of the gene products of the structural components of cell adhesion as well as LINC (linkers of nucleoskeleton and cytoskeleton) protein complexes. This study also reveals mis expressed downstream signaling processes in mutant cells, which could potentially lead to onset of the disease upon the application of engineered materials to substitute the role of conventional cues in instilling cellular behaviors in muscular dystrophies. Collectively, these data support the notion that lamin A is essential for proper cellular mechanotransduction from extracellular environment to the genome and impairment of the muscle cell differentiation in the pathogenic mechanism for lamin A associated muscular dystrophy.
Collapse
Affiliation(s)
- Subarna Dutta
- Department of Biochemistry, University of Calcutta, Kolkata, West Bengal, India
- Theomics International Private Limited, Bengaluru, India
| | - T Muraganadan
- CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | | |
Collapse
|
4
|
Pot SA, Lin Z, Shiu J, Benn MC, Vogel V. Growth factors and mechano-regulated reciprocal crosstalk with extracellular matrix tune the keratocyte-fibroblast/myofibroblast transition. Sci Rep 2023; 13:11350. [PMID: 37443325 PMCID: PMC10345140 DOI: 10.1038/s41598-023-37776-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Improper healing of the cornea after injury, infections or surgery can lead to corneal scar formation, which is associated with the transition of resident corneal keratocytes into activated fibroblasts and myofibroblasts (K-F/M). Myofibroblasts can create an extracellular matrix (ECM) niche in which fibrosis is promoted and perpetuated, resulting in progressive tissue opacification and vision loss. As a reversion back to quiescent keratocytes is essential to restore corneal transparency after injury, we characterized how growth factors with demonstrated profibrotic effects (PDGF, FGF, FBS, TGFβ1) induce the K-F/M transition, and whether their withdrawal can revert it. Indeed, the upregulated expression of αSMA and the associated changes in cytoskeletal architecture correlated with increases in cell contractility, fibronectin (Fn) and collagen matrix density and Fn fiber strain, as revealed by 2D cell culture, nanopillar cellular force mapping and a FRET-labeled Fn tension probe. Substrate mechanosensing drove a more complete K-F/M transition reversal following growth factor withdrawal on nanopillar arrays than on planar glass substrates. Using decellularized ECM scaffolds, we demonstrated that the K-F/M transition was inhibited in keratocytes reseeded onto myofibroblast-assembled, and/or collagen-1-rich ECM. This supports the presence of a myofibroblast-derived ECM niche that contains cues favoring tissue homeostasis rather than fibrosis.
Collapse
Affiliation(s)
- Simon A Pot
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
- Ophthalmology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
| | - Zhe Lin
- Ruisi (Fujian) Biomedical Engineering Research Center Co Ltd, 26-1 Wulongjiang Road, Fuzhou, 350100, People's Republic of China
| | - Jauye Shiu
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
- Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd, North District, Taichung City, Taiwan
| | - Mario C Benn
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
| |
Collapse
|
5
|
Mukherjee A, Ron JE, Hu HT, Nishimura T, Hanawa‐Suetsugu K, Behkam B, Mimori‐Kiyosue Y, Gov NS, Suetsugu S, Nain AS. Actin Filaments Couple the Protrusive Tips to the Nucleus through the I-BAR Domain Protein IRSp53 during the Migration of Cells on 1D Fibers. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207368. [PMID: 36698307 PMCID: PMC9982589 DOI: 10.1002/advs.202207368] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Indexed: 05/31/2023]
Abstract
The cell migration cycle, well-established in 2D, proceeds with forming new protrusive structures at the cell membrane and subsequent redistribution of contractile machinery. Three-dimensional (3D) environments are complex and composed of 1D fibers, and 1D fibers are shown to recapitulate essential features of 3D migration. However, the establishment of protrusive activity at the cell membrane and contractility in 1D fibrous environments remains partially understood. Here the role of membrane curvature regulator IRSp53 is examined as a coupler between actin filaments and plasma membrane during cell migration on single, suspended 1D fibers. IRSp53 depletion reduced cell-length spanning actin stress fibers that originate from the cell periphery, protrusive activity, and contractility, leading to uncoupling of the nucleus from cellular movements. A theoretical model capable of predicting the observed transition of IRSp53-depleted cells from rapid stick-slip migration to smooth and slower migration due to reduced actin polymerization at the cell edges is developed, which is verified by direct measurements of retrograde actin flow using speckle microscopy. Overall, it is found that IRSp53 mediates actin recruitment at the cellular tips leading to the establishment of cell-length spanning fibers, thus demonstrating a unique role of IRSp53 in controlling cell migration in 3D.
Collapse
Affiliation(s)
- Apratim Mukherjee
- Department of Mechanical EngineeringVirginia TechBlacksburgVA24061USA
| | - Jonathan Emanuel Ron
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovot7610001Israel
| | - Hooi Ting Hu
- Division of Biological ScienceGraduate School of Science and TechnologyNara Institute of Science and TechnologyIkoma630‐0192Japan
| | - Tamako Nishimura
- Division of Biological ScienceGraduate School of Science and TechnologyNara Institute of Science and TechnologyIkoma630‐0192Japan
| | | | - Bahareh Behkam
- Department of Mechanical EngineeringVirginia TechBlacksburgVA24061USA
| | - Yuko Mimori‐Kiyosue
- Laboratory for Molecular and Cellular DynamicsRIKEN Center for Biosystems Dynamics ResearchMinatojima‐minaminachiChuo‐kuKobeHyogo650‐0047Japan
| | - Nir Shachna Gov
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovot7610001Israel
| | - Shiro Suetsugu
- Division of Biological ScienceGraduate School of Science and TechnologyNara Institute of Science and TechnologyIkoma630‐0192Japan
- Data Science CenterNara Institute of Science and TechnologyIkoma630‐0192Japan
- Center for Digital Green‐innovationNara Institute of Science and TechnologyIkoma630‐0192Japan
| | | |
Collapse
|
6
|
Francis EA, Xiao H, Teng LH, Heinrich V. Mechanisms of frustrated phagocytic spreading of human neutrophils on antibody-coated surfaces. Biophys J 2022; 121:4714-4728. [PMID: 36242516 PMCID: PMC9748254 DOI: 10.1016/j.bpj.2022.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 09/20/2022] [Accepted: 10/12/2022] [Indexed: 12/15/2022] Open
Abstract
Complex motions of immune cells are an integral part of diapedesis, chemotaxis, phagocytosis, and other vital processes. To better understand how immune cells execute such motions, we present a detailed analysis of phagocytic spreading of human neutrophils on flat surfaces functionalized with different densities of immunoglobulin G (IgG) antibodies. We visualize the cell-substrate contact region at high resolution and without labels using reflection interference contrast microscopy and quantify how the area, shape, and position of the contact region evolves over time. We find that the likelihood of the cell commitment to spreading strongly depends on the surface density of IgG, but the rate at which the substrate-contact area of spreading cells increases does not. Validated by a theoretical companion study, our results resolve controversial notions about the mechanisms controlling cell spreading, establishing that active forces generated by the cytoskeleton rather than cell-substrate adhesion primarily drive cellular protrusion. Adhesion, on the other hand, aids phagocytic spreading by regulating the cell commitment to spreading, the maximum cell-substrate contact area, and the directional movement of the contact region.
Collapse
Affiliation(s)
- Emmet A Francis
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Hugh Xiao
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Lay Heng Teng
- Department of Biomedical Engineering, University of California Davis, Davis, California
| | - Volkmar Heinrich
- Department of Biomedical Engineering, University of California Davis, Davis, California.
| |
Collapse
|
7
|
Francis EA, Heinrich V. Integrative experimental/computational approach establishes active cellular protrusion as the primary driving force of phagocytic spreading by immune cells. PLoS Comput Biol 2022; 18:e1009937. [PMID: 36026476 PMCID: PMC9455874 DOI: 10.1371/journal.pcbi.1009937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 09/08/2022] [Accepted: 07/27/2022] [Indexed: 12/02/2022] Open
Abstract
The dynamic interplay between cell adhesion and protrusion is a critical determinant of many forms of cell motility. When modeling cell spreading on adhesive surfaces, traditional mathematical treatments often consider passive cell adhesion as the primary, if not exclusive, mechanistic driving force of this cellular motion. To better assess the contribution of active cytoskeletal protrusion to immune-cell spreading during phagocytosis, we here develop a computational framework that allows us to optionally investigate both purely adhesive spreading ("Brownian zipper hypothesis") as well as protrusion-dominated spreading ("protrusive zipper hypothesis"). We model the cell as an axisymmetric body of highly viscous fluid surrounded by a cortex with uniform surface tension and incorporate as potential driving forces of cell spreading an attractive stress due to receptor-ligand binding and an outward normal stress representing cytoskeletal protrusion, both acting on the cell boundary. We leverage various model predictions against the results of a directly related experimental companion study of human neutrophil phagocytic spreading on substrates coated with different densities of antibodies. We find that the concept of adhesion-driven spreading is incompatible with experimental results such as the independence of the cell-spreading speed on the density of immobilized antibodies. In contrast, the protrusive zipper model agrees well with experimental findings and, when adapted to simulate cell spreading on discrete adhesion sites, it also reproduces the observed positive correlation between antibody density and maximum cell-substrate contact area. Together, our integrative experimental/computational approach shows that phagocytic spreading is driven by cellular protrusion, and that the extent of spreading is limited by the density of adhesion sites.
Collapse
Affiliation(s)
- Emmet A. Francis
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States of America
| | - Volkmar Heinrich
- Department of Biomedical Engineering, University of California Davis, Davis, California, United States of America
| |
Collapse
|
8
|
Activity tracking isolation of Gelsemium elegans alkaloids and evaluation of their antihuman gastric cancer activity in vivo. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2021. [DOI: 10.1016/j.cjac.2021.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
9
|
Slater B, Li J, Indana D, Xie Y, Chaudhuri O, Kim T. Transient mechanical interactions between cells and viscoelastic extracellular matrix. SOFT MATTER 2021; 17:10274-10285. [PMID: 34137758 PMCID: PMC8695121 DOI: 10.1039/d0sm01911a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
During various physiological processes, such as wound healing and cell migration, cells continuously interact mechanically with a surrounding extracellular matrix (ECM). Contractile forces generated by the actin cytoskeleton are transmitted to a surrounding ECM, resulting in structural remodeling of the ECM. To better understand how matrix remodeling takes place, a myriad of in vitro experiments and simulations have been performed during recent decades. However, physiological ECMs are viscoelastic, exhibiting stress relaxation or creep over time. The time-dependent nature of matrix remodeling induced by cells remains poorly understood. Here, we employed a discrete model to investigate how the viscoelastic nature of ECMs affects matrix remodeling and stress profiles. In particular, we used explicit transient cross-linkers with varied density and unbinding kinetics to capture viscoelasticity unlike most of the previous models. Using this model, we quantified the time evolution of generation, propagation, and relaxation of stresses induced by a contracting cell in an ECM. It was found that matrix connectivity, regulated by fiber concentration and cross-linking density, significantly affects the magnitude and propagation of stress and subsequent matrix remodeling, as characterized by fiber displacements and local net deformation. In addition, we demonstrated how the base rate and force sensitivity of cross-linker unbinding regulate stress profiles and matrix remodeling. We verified simulation results using in vitro experiments performed with fibroblasts encapsulated in a three-dimensional collagen matrix. Our study provides key insights into the dynamics of physiologically relevant mechanical interactions between cells and a viscoelastic ECM.
Collapse
Affiliation(s)
- Brandon Slater
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN 47907, USA.
| | - Jing Li
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN 47907, USA.
| | - Dhiraj Indana
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, CA, 94305, USA
| | - Yihao Xie
- School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907, USA
| | - Ovijit Chaudhuri
- Department of Mechanical Engineering, Stanford University, 452 Escondido Mall, Stanford, CA, 94305, USA
| | - Taeyoon Kim
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Dr, West Lafayette, IN 47907, USA.
| |
Collapse
|
10
|
Keratin-Alginate Sponges Support Healing of Partial-Thickness Burns. Int J Mol Sci 2021; 22:ijms22168594. [PMID: 34445299 PMCID: PMC8395243 DOI: 10.3390/ijms22168594] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 07/27/2021] [Accepted: 08/07/2021] [Indexed: 01/07/2023] Open
Abstract
Deep partial-thickness burns damage most of the dermis and can cause severe pain, scarring, and mortality if left untreated. This study serves to evaluate the effectiveness of crosslinked keratin–alginate composite sponges as dermal substitutes for deep partial-thickness burns. Crosslinked keratin–alginate sponges were tested for the ability to support human dermal fibroblasts in vitro and to support the closure and healing of partial-thickness burn wounds in Sus scrofa pigs. Keratin–alginate composite sponges supported the enhanced proliferation of human dermal fibroblasts compared to alginate-only sponges and exhibited decreased contraction in vitro when compared to keratin only sponges. As dermal substitutes in vivo, the sponges supported the expression of keratin 14, alpha-smooth muscle actin, and collagen IV within wound sites, comparable to collagen sponges. Keratin–alginate composite sponges supported the regeneration of basement membranes in the wounds more than in collagen-treated wounds and non-grafted controls, suggesting the subsequent development of pathological scar tissues may be minimized. Results from this study indicate that crosslinked keratin–alginate sponges are suitable alternative dermal substitutes for clinical applications in wound healing and skin regeneration.
Collapse
|
11
|
Haneef K, Ghaffar Memon A, Saleem R, Batool F, Sadeeq M. B cell receptor (BCR) guided mechanotransduction: Critical hypothesis to instruct SARS-CoV-2 specific B cells to trigger proximal signalling and antibody reshaping. Med Hypotheses 2021; 153:110640. [PMID: 34271511 PMCID: PMC8259033 DOI: 10.1016/j.mehy.2021.110640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/08/2021] [Accepted: 07/04/2021] [Indexed: 11/29/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes COVID-19, has spread around the globe with remarkable consequences for the health of millions of people. Despite the approval of mRNA vaccines to prevent the spread of infection, long-term immunity must still be monitored. Targeting and modifying virus receptor binding regions to activate B cell receptors (BCRs) is a promising way to develop long-term immunity against SARS-CoV-2. After the interaction of antigens, BCRs undergo series of signal transduction events through phosphorylation of immune receptor tyrosine activation motifs (ITAMs) to produce neutralizing antibodies against pathogens. BCRs intricate entity displays remarkable capability to translate the external mechanosensing cues to reshape the immune mechanism. However, potential investigations suggesting how SARS-CoV-2 specific B cells respond to mechanosensing cues remain obscure. This study proposes a sophisticated hypothesis explaining how B cells isolated from the CP of SARS-CoV-2 infected patients may undergo a triggered series of B cell activation, BCR dynamics, proximal signalling, and antibody production on PDMS-embedded in-vitro antigen-presenting structures (APCs). These studies could provide detailed insights in the future for the development of structural and therapeutic entanglements to fight against pathogens.
Collapse
Affiliation(s)
- Kabeer Haneef
- School of Life Sciences, Institute for Immunology, Tsinghua University, Beijing, China.
| | - Abdul Ghaffar Memon
- Department of Environmental Engineering, NED University of Engineering and Technology, Karachi, Pakistan
| | - Rabia Saleem
- Oncology Ward, Children Hospital and Institute of Child Health, Lahore, Pakistan
| | - Farwa Batool
- Department of Biochemistry, University of Agriculture Faisalabad, Punjab, Pakistan
| | - Mohd Sadeeq
- School of Agriculture Sciences and Food Technology, Shandong University of Technology, Zibo, China
| |
Collapse
|
12
|
Gaston C, De Beco S, Doss B, Pan M, Gauquelin E, D'Alessandro J, Lim CT, Ladoux B, Delacour D. EpCAM promotes endosomal modulation of the cortical RhoA zone for epithelial organization. Nat Commun 2021; 12:2226. [PMID: 33850145 PMCID: PMC8044225 DOI: 10.1038/s41467-021-22482-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 03/11/2021] [Indexed: 01/13/2023] Open
Abstract
At the basis of cell shape and behavior, the organization of actomyosin and its ability to generate forces are widely studied. However, the precise regulation of this contractile network in space and time is unclear. Here, we study the role of the epithelial-specific protein EpCAM, a contractility modulator, in cell shape and motility. We show that EpCAM is required for stress fiber generation and front-rear polarity acquisition at the single cell level. In fact, EpCAM participates in the remodeling of a transient zone of active RhoA at the cortex of spreading epithelial cells. EpCAM and RhoA route together through the Rab35/EHD1 fast recycling pathway. This endosomal pathway spatially organizes GTP-RhoA to fine tune the activity of actomyosin resulting in polarized cell shape and development of intracellular stiffness and traction forces. Impairment of GTP-RhoA endosomal trafficking either by silencing EpCAM or by expressing Rab35/EHD1 mutants prevents proper myosin-II activity, stress fiber formation and ultimately cell polarization. Collectively, this work shows that the coupling between co-trafficking of EpCAM and RhoA, and actomyosin rearrangement is pivotal for cell spreading, and advances our understanding of how biochemical and mechanical properties promote cell plasticity.
Collapse
Affiliation(s)
- Cécile Gaston
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France
| | - Simon De Beco
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France
| | - Bryant Doss
- Mechanobiology Institute, T-lab, Singapore, Singapore
| | - Meng Pan
- Mechanobiology Institute, T-lab, Singapore, Singapore
| | - Estelle Gauquelin
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France
| | - Joseph D'Alessandro
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France
| | | | - Benoit Ladoux
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France
| | - Delphine Delacour
- Cell Adhesion and Mechanics, Institut Jacques Monod, CNRS UMR7592, Paris Diderot University, Paris, France.
| |
Collapse
|
13
|
Complementary mesoscale dynamics of spectrin and acto-myosin shape membrane territories during mechanoresponse. Nat Commun 2020; 11:5108. [PMID: 33037189 PMCID: PMC7547731 DOI: 10.1038/s41467-020-18825-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 09/11/2020] [Indexed: 11/08/2022] Open
Abstract
The spectrin-based membrane skeleton is a major component of the cell cortex. While expressed by all metazoans, its dynamic interactions with the other cortex components, including the plasma membrane or the acto-myosin cytoskeleton, are poorly understood. Here, we investigate how spectrin re-organizes spatially and dynamically under the membrane during changes in cell mechanics. We find spectrin and acto-myosin to be spatially distinct but cooperating during mechanical challenges, such as cell adhesion and contraction, or compression, stretch and osmolarity fluctuations, creating a cohesive cortex supporting the plasma membrane. Actin territories control protrusions and contractile structures while spectrin territories concentrate in retractile zones and low-actin density/inter-contractile regions, acting as a fence that organize membrane trafficking events. We unveil here the existence of a dynamic interplay between acto-myosin and spectrin necessary to support a mesoscale organization of the lipid bilayer into spatially-confined cortical territories during cell mechanoresponse.
Collapse
|
14
|
Stick-slip model for actin-driven cell protrusions, cell polarization, and crawling. Proc Natl Acad Sci U S A 2020; 117:24670-24678. [PMID: 32958682 DOI: 10.1073/pnas.2011785117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cell crawling requires the generation of intracellular forces by the cytoskeleton and their transmission to an extracellular substrate through specific adhesion molecules. Crawling cells show many features of excitable systems, such as spontaneous symmetry breaking and crawling in the absence of external cues, and periodic and propagating waves of activity. Mechanical instabilities in the active cytoskeleton network and feedback loops in the biochemical network of activators and repressors of cytoskeleton dynamics have been invoked to explain these dynamical features. Here, I show that the interplay between the dynamics of cell-substrate adhesion and linear cellular mechanics is sufficient to reproduce many nonlinear dynamical patterns observed in spreading and crawling cells. Using an analytical formalism of the molecular clutch model of cell adhesion, regulated by local mechanical forces, I show that cellular traction forces exhibit stick-slip dynamics resulting in periodic waves of protrusion/retraction and propagating waves along the cell edge. This can explain spontaneous symmetry breaking and polarization of spreading cells, leading to steady crawling or bipedal motion, and bistability, where persistent cell motion requires a sufficiently strong transient external stimulus. The model also highlights the role of membrane tension in providing the long-range mechanical communication across the cell required for symmetry breaking.
Collapse
|
15
|
Quantitative Phase Imaging of Spreading Fibroblasts Identifies the Role of Focal Adhesion Kinase in the Stabilization of the Cell Rear. Biomolecules 2020; 10:biom10081089. [PMID: 32707896 PMCID: PMC7463699 DOI: 10.3390/biom10081089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/14/2020] [Accepted: 07/20/2020] [Indexed: 12/11/2022] Open
Abstract
Cells attaching to the extracellular matrix spontaneously acquire front-rear polarity. This self-organization process comprises spatial activation of polarity signaling networks and the establishment of a protruding cell front and a non-protruding cell rear. Cell polarization also involves the reorganization of cell mass, notably the nucleus that is positioned at the cell rear. It remains unclear, however, how these processes are regulated. Here, using coherence-controlled holographic microscopy (CCHM) for non-invasive live-cell quantitative phase imaging (QPI), we examined the role of the focal adhesion kinase (FAK) and its interacting partner Rack1 in dry mass distribution in spreading Rat2 fibroblasts. We found that FAK-depleted cells adopt an elongated, bipolar phenotype with a high central body mass that gradually decreases toward the ends of the elongated processes. Further characterization of spreading cells showed that FAK-depleted cells are incapable of forming a stable rear; rather, they form two distally positioned protruding regions. Continuous protrusions at opposite sides results in an elongated cell shape. In contrast, Rack1-depleted cells are round and large with the cell mass sharply dropping from the nuclear area towards the basal side. We propose that FAK and Rack1 act differently yet coordinately to establish front-rear polarity in spreading cells.
Collapse
|
16
|
Abstract
For many years, major differences in morphology, motility, and mechanical characteristics have been observed between transformed cancer and normal cells. In this review, we consider these differences as linked to different states of normal and transformed cells that involve distinct mechanosensing and motility pathways. There is a strong correlation between repeated tissue healing and/or inflammation and the probability of cancer, both of which involve growth in adult tissues. Many factors are likely needed to enable growth, including the loss of rigidity sensing, but recent evidence indicates that microRNAs have important roles in causing the depletion of growth-suppressing proteins. One microRNA, miR-21, is overexpressed in many different tissues during both healing and cancer. Normal cells can become transformed by the depletion of cytoskeletal proteins that results in the loss of mechanosensing, particularly rigidity sensing. Conversely, the transformed state can be reversed by the expression of cytoskeletal proteins-without direct alteration of hormone receptor levels. In this review, we consider the different stereotypical forms of motility and mechanosensory systems. A major difference between normal and transformed cells involves a sensitivity of transformed cells to mechanical perturbations. Thus, understanding the different mechanical characteristics of transformed cells may enable new approaches to treating wound healing and cancer.
Collapse
Affiliation(s)
- Michael Sheetz
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, Singapore 117411
- Molecular MechanoMedicine Program and Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555, USA;
| |
Collapse
|
17
|
Al-Rekabi Z, Fura AM, Juhlin I, Yassin A, Popowics TE, Sniadecki NJ. Hyaluronan-CD44 interactions mediate contractility and migration in periodontal ligament cells. Cell Adh Migr 2019; 13:138-150. [PMID: 30676222 PMCID: PMC6527381 DOI: 10.1080/19336918.2019.1568140] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The role of hyaluronan (HA) in periodontal healing has been speculated via its interaction with the CD44 receptor. While HA-CD44 interactions have previously been implicated in numerous cell types; effect and mechanism of exogenous HA on periodontal ligament (PDL) cells is less clear. Herein, we examine the effect of exogenous HA on contractility and migration in human and murine PDL cells using arrays of microposts and time-lapse microscopy. Our findings observed HA-treated human PDL cells as more contractile and less migratory than untreated cells. Moreover, the effect of HA on contractility and focal adhesion area was abrogated when PDL cells were treated with Y27632, an inhibitor of rho-dependent kinase, but not when these cells were treated with ML-7, an inhibitor of myosin light chain kinase. Our results provide insight into the mechanobiology of PDL cells, which may contribute towards the development of therapeutic strategies for periodontal healing and tissue regeneration.
Collapse
Affiliation(s)
- Zeinab Al-Rekabi
- a Department of Mechanical Engineering , University of Washington , Seattle , WA , USA
| | - Adriane M Fura
- b Department of Bioengineering , University of Washington , Seattle , WA , USA
| | - Ilsa Juhlin
- a Department of Mechanical Engineering , University of Washington , Seattle , WA , USA
| | - Alaa Yassin
- c Department of Periodontics , University of Washington , Seattle , WA , USA
| | - Tracy E Popowics
- d Department of Oral Health Sciences , University of Washington , Seattle , WA , USA
| | - Nathan J Sniadecki
- a Department of Mechanical Engineering , University of Washington , Seattle , WA , USA.,b Department of Bioengineering , University of Washington , Seattle , WA , USA.,e Institute for Stem Cell and Regenerative Medicine , University of Washington , Seattle , WA , USA
| |
Collapse
|
18
|
Tvorogova A, Saidova A, Smirnova T, Vorobjev I. Dynamic microtubules drive fibroblast spreading. Biol Open 2018; 7:7/12/bio038968. [PMID: 30545950 PMCID: PMC6310885 DOI: 10.1242/bio.038968] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When cells with a mesenchymal type of motility come into contact with an adhesive substrate they adhere and start spreading by the formation of lamellipodia. Using a label-free approach and virtual synchronization approach we analyzed spreading in fibroblasts and cancer cells. In all cell lines spreading is a non-linear process undergoing isotropic or anisotropic modes with first fast (5–20 min) and then slow (30–120 min) phases. In the first 10 min cell area increases 2–4 times, while the absolute rate of initial spreading decreases 2–8 times. Fast spreading depends on actin polymerization and dynamic microtubules. Inhibition of microtubule growth was sufficient for a slowdown of initial spreading. Inhibition of myosin II in the presence of stable microtubules restored fast spreading. Inhibition of actin polymerization or complete depolymerization of microtubules slowed down fast spreading. However, in these cases inhibition of myosin II only partially restored spreading kinetics. We conclude that rapid growth of microtubules towards cell margins at the first stage of cell spreading temporarily inhibits phosphorylation of myosin II and is essential for the fast isotropic spreading. Comparison of the fibroblasts with cancer cells shows that fast spreading in different cell types shares similar kinetics and mechanisms, and strongly depends on dynamic microtubules. Summary: Cell spreading is a non-linear process. The fast spreading phase depends on dynamic microtubules (MTs). Rapid growth of MTs towards the cell membrane promotes the temporal relaxation of acto-myosin contractility.
Collapse
Affiliation(s)
- Anna Tvorogova
- Department of Electron Microscopy, A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov State University, 1-40 Leninskie Gory, Moscow 119991, Russia
| | - Aleena Saidova
- Biological Faculty, M.V. Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow 119991, Russia
| | - Tatiana Smirnova
- Biological Faculty, M.V. Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow 119991, Russia
| | - Ivan Vorobjev
- Department of Electron Microscopy, A.N. Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov State University, 1-40 Leninskie Gory, Moscow 119991, Russia .,Biological Faculty, M.V. Lomonosov Moscow State University, 1-12 Leninskie Gory, Moscow 119991, Russia.,Department of Biology, School of Science and Technology, Nazarbayev University, Kabanbay Batyr ave. 53, Astana 010000, Kazakhstan
| |
Collapse
|
19
|
Profiling cellular morphodynamics by spatiotemporal spectrum decomposition. PLoS Comput Biol 2018; 14:e1006321. [PMID: 30071020 PMCID: PMC6091976 DOI: 10.1371/journal.pcbi.1006321] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 08/14/2018] [Accepted: 06/22/2018] [Indexed: 12/12/2022] Open
Abstract
Cellular morphology and associated morphodynamics are widely used for qualitative and quantitative assessments of cell state. Here we implement a framework to profile cellular morphodynamics based on an adaptive decomposition of local cell boundary motion into instantaneous frequency spectra defined by the Hilbert-Huang transform (HHT). Our approach revealed that spontaneously migrating cells with approximately homogeneous molecular makeup show remarkably consistent instantaneous frequency distributions, though they have markedly heterogeneous mobility. Distinctions in cell edge motion between these cells are captured predominantly by differences in the magnitude of the frequencies. We found that acute photo-inhibition of Vav2 guanine exchange factor, an activator of the Rho family of signaling proteins coordinating cell motility, produces significant shifts in the frequency distribution, but does not affect frequency magnitude. We therefore concluded that the frequency spectrum encodes the wiring of the molecular circuitry that regulates cell boundary movements, whereas the magnitude captures the activation level of the circuitry. We also used HHT spectra as multi-scale spatiotemporal features in statistical region merging to identify subcellular regions of distinct motion behavior. In line with our conclusion that different HHT spectra relate to different signaling regimes, we found that subcellular regions with different morphodynamics indeed exhibit distinct Rac1 activities. This algorithm thus can serve as an accurate and sensitive classifier of cellular morphodynamics to pinpoint spatial and temporal boundaries between signaling regimes. Many studies in cell biology employ global shape descriptors to probe mechanisms of cell morphogenesis. Here, we implement a framework in this paper to profile cellular morphodynamics very locally. We employ the Hilbert-Huang transform (HHT) to extract along the entire cell edge spectra of instantaneous edge motion frequency and magnitude and use them to classify overall cell behavior as well as subcellular edge sectors of distinct dynamics. We find in fibroblast-like COS7 cells that the marked heterogeneity in mobility of an unstimulated population is fully captured by differences in the magnitude spectra, while the frequency spectra are conserved between cells. Using optogenetics to acutely inhibit morphogenetic signaling pathways we find that these molecular shifts are reflected by changes in the frequency spectra but not in the magnitude spectra. After clustering cell edge sectors with distinct morphodynamics we observe in cells expressing a Rac1 activity biosensor that the sectors with different frequency spectra associate with different signaling intensity and dynamics. Together, these observations let us conclude that the frequency spectrum encodes the wiring of the molecular circuitry that regulates edge movements, whereas the magnitude captures the activation level of the circuitry.
Collapse
|
20
|
Ozcelikkale A, Dutton JC, Grinnell F, Han B. Effects of dynamic matrix remodelling on en masse migration of fibroblasts on collagen matrices. J R Soc Interface 2018; 14:rsif.2017.0287. [PMID: 28978745 DOI: 10.1098/rsif.2017.0287] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 09/12/2017] [Indexed: 12/19/2022] Open
Abstract
Fibroblast migration plays a key role during various physiological and pathological processes. Although migration of individual fibroblasts has been well studied, migration in vivo often involves simultaneous locomotion of fibroblasts sited in close proximity, so-called 'en masse migration', during which intensive cell-cell interactions occur. This study aims to understand the effects of matrix mechanical environments on the cell-matrix and cell-cell interactions during en masse migration of fibroblasts on collagen matrices. Specifically, we hypothesized that a group of migrating cells can significantly deform the matrix, whose mechanical microenvironment dramatically changes compared with the undeformed state, and the alteration of the matrix microenvironment reciprocally affects cell migration. This hypothesis was tested by time-resolved measurements of cell and extracellular matrix movement during en masse migration on collagen hydrogels with varying concentrations. The results illustrated that a group of cells generates significant spatio-temporal deformation of the matrix before and during the migration. Cells on soft collagen hydrogels migrate along tortuous paths, but, as the matrix stiffness increases, cell migration patterns become aligned with each other and show coordinated migration paths. As cells migrate, the matrix is locally compressed, resulting in a locally stiffened and dense matrix across the collagen concentration range studied.
Collapse
Affiliation(s)
- Altug Ozcelikkale
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - J Craig Dutton
- Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Frederick Grinnell
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Bumsoo Han
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA .,Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.,Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
21
|
Sakane A, Yoshizawa S, Yokota H, Sasaki T. Dancing Styles of Collective Cell Migration: Image-Based Computational Analysis of JRAB/MICAL-L2. Front Cell Dev Biol 2018; 6:4. [PMID: 29468157 PMCID: PMC5807911 DOI: 10.3389/fcell.2018.00004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/19/2018] [Indexed: 01/01/2023] Open
Abstract
Collective cell migration is observed during morphogenesis, angiogenesis, and wound healing, and this type of cell migration also contributes to efficient metastasis in some kinds of cancers. Because collectively migrating cells are much better organized than a random assemblage of individual cells, there seems to be a kind of order in migrating clusters. Extensive research has identified a large number of molecules involved in collective cell migration, and these factors have been analyzed using dramatic advances in imaging technology. To date, however, it remains unclear how myriad cells are integrated as a single unit. Recently, we observed unbalanced collective cell migrations that can be likened to either precision dancing or awa-odori, Japanese traditional dancing similar to the style at Rio Carnival, caused by the impairment of the conformational change of JRAB/MICAL-L2. This review begins with a brief history of image-based computational analyses on cell migration, explains why quantitative analysis of the stylization of collective cell behavior is difficult, and finally introduces our recent work on JRAB/MICAL-L2 as a successful example of the multidisciplinary approach combining cell biology, live imaging, and computational biology. In combination, these methods have enabled quantitative evaluations of the “dancing style” of collective cell migration.
Collapse
Affiliation(s)
- Ayuko Sakane
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| | - Shin Yoshizawa
- Image Processing Research Team, RIKEN Center for Advanced Photonicsm RIKEN, Wako, Japan
| | - Hideo Yokota
- Image Processing Research Team, RIKEN Center for Advanced Photonicsm RIKEN, Wako, Japan
| | - Takuya Sasaki
- Department of Biochemistry, Tokushima University Graduate School of Medical Sciences, Tokushima, Japan
| |
Collapse
|
22
|
Chabanon M, Stachowiak JC, Rangamani P. Systems biology of cellular membranes: a convergence with biophysics. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28475297 PMCID: PMC5561455 DOI: 10.1002/wsbm.1386] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 02/02/2017] [Accepted: 02/21/2017] [Indexed: 12/12/2022]
Abstract
Systems biology and systems medicine have played an important role in the last two decades in shaping our understanding of biological processes. While systems biology is synonymous with network maps and '-omics' approaches, it is not often associated with mechanical processes. Here, we make the case for considering the mechanical and geometrical aspects of biological membranes as a key step in pushing the frontiers of systems biology of cellular membranes forward. We begin by introducing the basic components of cellular membranes, and highlight their dynamical aspects. We then survey the functions of the plasma membrane and the endomembrane system in signaling, and discuss the role and origin of membrane curvature in these diverse cellular processes. We further give an overview of the experimental and modeling approaches to study membrane phenomena. We close with a perspective on the converging futures of systems biology and membrane biophysics, invoking the need to include physical variables such as location and geometry in the study of cellular membranes. WIREs Syst Biol Med 2017, 9:e1386. doi: 10.1002/wsbm.1386 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Morgan Chabanon
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| | - Jeanne C Stachowiak
- Department of Biomedical Engineering, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
23
|
Yeh YC, Corbin EA, Caliari SR, Ouyang L, Vega SL, Truitt R, Han L, Margulies KB, Burdick JA. Mechanically dynamic PDMS substrates to investigate changing cell environments. Biomaterials 2017; 145:23-32. [PMID: 28843064 DOI: 10.1016/j.biomaterials.2017.08.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/28/2017] [Accepted: 08/16/2017] [Indexed: 01/06/2023]
Abstract
Mechanics of the extracellular matrix (ECM) play a pivotal role in governing cell behavior, such as cell spreading and differentiation. ECM mechanics have been recapitulated primarily in elastic hydrogels, including with dynamic properties to mimic complex behaviors (e.g., fibrosis); however, these dynamic hydrogels fail to introduce the viscoelastic nature of many tissues. Here, we developed a two-step crosslinking strategy to first form (via platinum-catalyzed crosslinking) networks of polydimethylsiloxane (PDMS) and then to increase PDMS crosslinking (via thiol-ene click reaction) in a temporally-controlled manner. This photoinitiated reaction increased the compressive modulus of PDMS up to 10-fold within minutes and was conducted under cytocompatible conditions. With stiffening, cells displayed increased spreading, changing from ∼1300 to 1900 μm2 and from ∼2700 to 4600 μm2 for fibroblasts and mesenchymal stem cells, respectively. In addition, higher myofibroblast activation (from ∼2 to 20%) for cardiac fibroblasts was observed with increasing PDMS substrate stiffness. These results indicate a cellular response to changes in PDMS substrate mechanics, along with a demonstration of a mechanically dynamic and photoresponsive PDMS substrate platform to model the dynamic behavior of ECM.
Collapse
Affiliation(s)
- Yi-Cheun Yeh
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Elise A Corbin
- Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Steven R Caliari
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Liu Ouyang
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Sebastián L Vega
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Rachel Truitt
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, USA
| | | | - Jason A Burdick
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
24
|
Pontes B, Monzo P, Gole L, Le Roux AL, Kosmalska AJ, Tam ZY, Luo W, Kan S, Viasnoff V, Roca-Cusachs P, Tucker-Kellogg L, Gauthier NC. Membrane tension controls adhesion positioning at the leading edge of cells. J Cell Biol 2017; 216:2959-2977. [PMID: 28687667 PMCID: PMC5584154 DOI: 10.1083/jcb.201611117] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 04/04/2017] [Accepted: 06/01/2017] [Indexed: 11/22/2022] Open
Abstract
Pontes et al. show that plasma membrane mechanics exerts an upstream control during cell motility. Variations in plasma membrane tension orchestrate the behavior of the cell leading edge, with increase–decrease cycles in tension promoting adhesion row positioning. Cell migration is dependent on adhesion dynamics and actin cytoskeleton remodeling at the leading edge. These events may be physically constrained by the plasma membrane. Here, we show that the mechanical signal produced by an increase in plasma membrane tension triggers the positioning of new rows of adhesions at the leading edge. During protrusion, as membrane tension increases, velocity slows, and the lamellipodium buckles upward in a myosin II–independent manner. The buckling occurs between the front of the lamellipodium, where nascent adhesions are positioned in rows, and the base of the lamellipodium, where a vinculin-dependent clutch couples actin to previously positioned adhesions. As membrane tension decreases, protrusion resumes and buckling disappears, until the next cycle. We propose that the mechanical signal of membrane tension exerts upstream control in mechanotransduction by periodically compressing and relaxing the lamellipodium, leading to the positioning of adhesions at the leading edge of cells.
Collapse
Affiliation(s)
- Bruno Pontes
- Mechanobiology Institute, National University of Singapore, Singapore.,Laboratório de Pinças Óticas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pascale Monzo
- Mechanobiology Institute, National University of Singapore, Singapore.,Institute FIRC (Italian Foundation for Cancer Research) of Molecular Oncology (IFOM-FIRC), Milan, Italy
| | - Laurent Gole
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Anita Joanna Kosmalska
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Zhi Yang Tam
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Weiwei Luo
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Sophie Kan
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore, Singapore.,Centre National de la Recherche Scientifique, École Supérieure de Physique et de Chimie Industrielles Paristech, Paris, France
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain.,University of Barcelona, Barcelona, Spain
| | - Lisa Tucker-Kellogg
- Mechanobiology Institute, National University of Singapore, Singapore.,Centre for Computational Biology, Duke-National University of Singapore Graduate Medical School, Singapore
| | - Nils C Gauthier
- Mechanobiology Institute, National University of Singapore, Singapore .,Institute FIRC (Italian Foundation for Cancer Research) of Molecular Oncology (IFOM-FIRC), Milan, Italy
| |
Collapse
|
25
|
Frustrated Phagocytic Spreading of J774A-1 Macrophages Ends in Myosin II-Dependent Contraction. Biophys J 2017; 111:2698-2710. [PMID: 28002746 DOI: 10.1016/j.bpj.2016.11.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 10/12/2016] [Accepted: 11/11/2016] [Indexed: 01/13/2023] Open
Abstract
Conventional studies of dynamic phagocytic behavior have been limited in terms of spatial and temporal resolution due to the inherent three-dimensionality and small features of phagocytosis. To overcome these issues, we use a series of frustrated phagocytosis assays to quantitatively characterize phagocytic spreading dynamics. Our investigation reveals that frustrated phagocytic spreading occurs in phases and is punctuated by a distinct period of contraction. The spreading duration and peak contact areas are independent of the surface opsonin density, although the opsonin density does affect the likelihood that a cell will spread. This reinforces the idea that phagocytosis dynamics are primarily dictated by cytoskeletal activity. Structured illumination microscopy reveals that F-actin is reorganized during the course of frustrated phagocytosis. F-actin in early stages is consistent with that observed in lamellipodial protrusions. During the contraction phase, it is bundled into fibers that surround the cell and is reminiscent of a contractile belt. Using traction force microscopy, we show that cells exert significant strain on the underlying substrate during the contraction phase but little strain during the spreading phase, demonstrating that phagocytes actively constrict during late-stage phagocytosis. We also find that late-stage contraction initiates after the cell surface area increases by 225%, which is consistent with the point at which cortical tension begins to rise. Moreover, reducing tension by exposing cells to hypertonic buffer shifts the onset of contraction to occur in larger contact areas. Together, these findings provide further evidence that tension plays a significant role in signaling late-stage phagocytic activity.
Collapse
|
26
|
Sala S, Van Troys M, Medves S, Catillon M, Timmerman E, Staes A, Schaffner-Reckinger E, Gevaert K, Ampe C. Expanding the Interactome of TES by Exploiting TES Modules with Different Subcellular Localizations. J Proteome Res 2017; 16:2054-2071. [DOI: 10.1021/acs.jproteome.7b00034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stefano Sala
- Department of Biochemistry, Ghent University, 9000 Gent, Belgium
| | | | - Sandrine Medves
- Cytoskeleton
and Cell Plasticity Lab, Life Sciences Research Unit − FSTC, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
- Laboratory of Experimental Cancer Research, LIH, 1445 Strassen, Luxembourg
| | - Marie Catillon
- Cytoskeleton
and Cell Plasticity Lab, Life Sciences Research Unit − FSTC, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Evy Timmerman
- Department of Biochemistry, Ghent University, 9000 Gent, Belgium
- VIB Medical Biotechnology Center, 9000 Gent, Belgium
| | - An Staes
- Department of Biochemistry, Ghent University, 9000 Gent, Belgium
- VIB Medical Biotechnology Center, 9000 Gent, Belgium
| | - Elisabeth Schaffner-Reckinger
- Cytoskeleton
and Cell Plasticity Lab, Life Sciences Research Unit − FSTC, University of Luxembourg, 4365 Esch-sur-Alzette, Luxembourg
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, 9000 Gent, Belgium
- VIB Medical Biotechnology Center, 9000 Gent, Belgium
| | - Christophe Ampe
- Department of Biochemistry, Ghent University, 9000 Gent, Belgium
| |
Collapse
|
27
|
Changede R, Sheetz M. Integrin and cadherin clusters: A robust way to organize adhesions for cell mechanics. Bioessays 2016; 39:1-12. [PMID: 27930828 DOI: 10.1002/bies.201600123] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies at the nanometer scale have revealed that relatively uniform clusters of adhesion proteins (50-100 nm) constitute the modular units of cell adhesion sites in both cell-matrix and cell-cell adhesions. Super resolution microscopy and membrane protein diffusion studies both suggest that even large focal adhesions are formed of 100 nm clusters that are loosely aggregated. Clusters of 20-50 adhesion molecules (integrins or cadherins) can support large forces through avidity binding interactions but can also be disassembled or endocytosed rapidly. Assembly of the clusters of integrins is force-independent and involves gathering integrins at ligand binding sites where they are stabilized by cytoplasmic adhesion proteins that crosslink the integrin cytoplasmic tails plus connect the clusters to the cell cytoskeleton. Cooperative-signaling events can occur in a single cluster without cascading to other clusters. Thus, the clusters appear to be very important elements in many cellular processes and can be considered as a critical functional module.
Collapse
Affiliation(s)
- Rishita Changede
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Michael Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| |
Collapse
|
28
|
Barnhart EL, Allard J, Lou SS, Theriot JA, Mogilner A. Adhesion-Dependent Wave Generation in Crawling Cells. Curr Biol 2016; 27:27-38. [PMID: 27939309 DOI: 10.1016/j.cub.2016.11.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/26/2016] [Accepted: 11/03/2016] [Indexed: 11/27/2022]
Abstract
Dynamic actin networks are excitable. In migrating cells, feedback loops can amplify stochastic fluctuations in actin dynamics, often resulting in traveling waves of protrusion. The precise contributions of various molecular and mechanical interactions to wave generation have been difficult to disentangle, in part due to complex cellular morphodynamics. Here we used a relatively simple cell type-the fish epithelial keratocyte-to define a set of mechanochemical feedback loops underlying actin network excitability and wave generation. Although keratocytes are normally characterized by the persistent protrusion of a broad leading edge, increasing cell-substrate adhesion strength results in waving protrusion of a short leading edge. We show that protrusion waves are due to fluctuations in actin polymerization rates and that overexpression of VASP, an actin anti-capping protein that promotes actin polymerization, switches highly adherent keratocytes from waving to persistent protrusion. Moreover, VASP localizes both to adhesion complexes and to the leading edge. Based on these results, we developed a mathematical model for protrusion waves in which local depletion of VASP from the leading edge by adhesions-along with lateral propagation of protrusion due to the branched architecture of the actin network and negative mechanical feedback from the cell membrane-results in regular protrusion waves. Consistent with our model simulations, we show that VASP localization at the leading edge oscillates, with VASP leading-edge enrichment greatest just prior to protrusion initiation. We propose that the mechanochemical feedbacks underlying wave generation in keratocytes may constitute a general module for establishing excitable actin dynamics in other cellular contexts.
Collapse
Affiliation(s)
- Erin L Barnhart
- Department of Biochemistry and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jun Allard
- Department of Mathematics and Department of Physics, University of California, Irvine, Irvine, CA 92697, USA
| | - Sunny S Lou
- Department of Biochemistry and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA
| | - Julie A Theriot
- Department of Biochemistry and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
| | - Alex Mogilner
- Courant Institute and Department of Biology, New York University, New York, NY 10012, USA.
| |
Collapse
|
29
|
Neumann J, Gottschalk KE. The integrin–talin complex under force. Protein Eng Des Sel 2016; 29:503-512. [DOI: 10.1093/protein/gzw031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/07/2016] [Accepted: 06/21/2016] [Indexed: 12/20/2022] Open
|
30
|
Carey SP, Goldblatt ZE, Martin KE, Romero B, Williams RM, Reinhart-King CA. Local extracellular matrix alignment directs cellular protrusion dynamics and migration through Rac1 and FAK. Integr Biol (Camb) 2016; 8:821-35. [PMID: 27384462 PMCID: PMC4980151 DOI: 10.1039/c6ib00030d] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cell migration within 3D interstitial microenvironments is sensitive to extracellular matrix (ECM) properties, but the mechanisms that regulate migration guidance by 3D matrix features remain unclear. To examine the mechanisms underlying the cell migration response to aligned ECM, which is prevalent at the tumor-stroma interface, we utilized time-lapse microscopy to compare the behavior of MDA-MB-231 breast adenocarcinoma cells within randomly organized and well-aligned 3D collagen ECM. We developed a novel experimental system in which cellular morphodynamics during initial 3D cell spreading served as a reductionist model for the complex process of matrix-directed 3D cell migration. Using this approach, we found that ECM alignment induced spatial anisotropy of cells' matrix probing by promoting protrusion frequency, persistence, and lengthening along the alignment axis and suppressing protrusion dynamics orthogonal to alignment. Preference for on-axis behaviors was dependent upon FAK and Rac1 signaling and translated across length and time scales such that cells within aligned ECM exhibited accelerated elongation, front-rear polarization, and migration relative to cells in random ECM. Together, these findings indicate that adhesive and protrusive signaling allow cells to respond to coordinated physical cues in the ECM, promoting migration efficiency and cell migration guidance by 3D matrix structure.
Collapse
Affiliation(s)
- Shawn P Carey
- Department of Biomedical Engineering, Cornell University, 302 Weill Hall, 526 Campus Rd, Ithaca, New York 14853, USA.
| | | | | | | | | | | |
Collapse
|
31
|
Klímová Z, Bráborec V, Maninová M, Čáslavský J, Weber MJ, Vomastek T. Symmetry breaking in spreading RAT2 fibroblasts requires the MAPK/ERK pathway scaffold RACK1 that integrates FAK, p190A-RhoGAP and ERK2 signaling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2189-200. [PMID: 27212270 DOI: 10.1016/j.bbamcr.2016.05.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 04/22/2016] [Accepted: 05/17/2016] [Indexed: 11/28/2022]
Abstract
The spreading of adhering cells is a morphogenetic process during which cells break spherical or radial symmetry and adopt migratory polarity with spatially segregated protruding cell front and non-protruding cell rear. The organization and regulation of these symmetry-breaking events, which are both complex and stochastic, are not fully understood. Here we show that in radially spreading cells, symmetry breaking commences with the development of discrete non-protruding regions characterized by large but sparse focal adhesions and long peripheral actin bundles. Establishment of this non-protruding static region specifies the distally oriented protruding cell front and thus determines the polarity axis and the direction of cell migration. The development of non-protruding regions requires ERK2 and the ERK pathway scaffold protein RACK1. RACK1 promotes adhesion-mediated activation of ERK2 that in turn inhibits p190A-RhoGAP signaling by reducing the peripheral localization of p190A-RhoGAP. We propose that sustained ERK signaling at the prospective cell rear induces p190A-RhoGAP depletion from the cell periphery resulting in peripheral actin bundles and cell rear formation. Since cell adhesion activates both ERK and p190A-RhoGAP signaling this constitutes a spatially confined incoherent feed-forward signaling circuit.
Collapse
Affiliation(s)
| | | | | | | | - Michael J Weber
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA
| | - Tomáš Vomastek
- Institute of Microbiology AS CR, Prague, Czech Republic.
| |
Collapse
|
32
|
Brill-Karniely Y, Nisenholz N, Rajendran K, Dang Q, Krishnan R, Zemel A. Dynamics of cell area and force during spreading. Biophys J 2016; 107:L37-L40. [PMID: 25517168 DOI: 10.1016/j.bpj.2014.10.049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/28/2014] [Accepted: 10/09/2014] [Indexed: 11/16/2022] Open
Abstract
Experiments on human pulmonary artery endothelial cells are presented to show that cell area and the force exerted on a substrate increase simultaneously, but with different rates during spreading; rapid-force increase systematically occurred several minutes past initial spreading. We examine this theoretically and present three complementary mechanisms that may accompany the development of lamellar stress during spreading and underlie the observed behavior. These include: 1), the dynamics of cytoskeleton assembly at the cell basis; 2), the strengthening of acto-myosin forces in response to the generated lamellar stresses; and 3), the passive strain-stiffening of the cytoskeleton.
Collapse
Affiliation(s)
- Yifat Brill-Karniely
- Institute of Dental Sciences and Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, Israel
| | - Noam Nisenholz
- Institute of Dental Sciences and Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, Israel
| | - Kavitha Rajendran
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Quynh Dang
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Ramaswamy Krishnan
- Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Assaf Zemel
- Institute of Dental Sciences and Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, Israel.
| |
Collapse
|
33
|
Meacci G, Wolfenson H, Liu S, Stachowiak MR, Iskratsch T, Mathur A, Ghassemi S, Gauthier N, Tabdanov E, Lohner J, Gondarenko A, Chander AC, Roca-Cusachs P, O'Shaughnessy B, Hone J, Sheetz MP. α-Actinin links extracellular matrix rigidity-sensing contractile units with periodic cell-edge retractions. Mol Biol Cell 2016; 27:3471-3479. [PMID: 27122603 PMCID: PMC5221581 DOI: 10.1091/mbc.e16-02-0107] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/20/2016] [Indexed: 11/11/2022] Open
Abstract
During spreading and migration, the leading edges of cells undergo periodic protrusion-retraction cycles. The functional purpose of these cycles is unclear. Here, using submicrometer polydimethylsiloxane pillars as substrates for cell spreading, we show that periodic edge retractions coincide with peak forces produced by local contractile units (CUs) that assemble and disassemble along the cell edge to test matrix rigidity. We find that, whereas actin rearward flow produces a relatively constant force inward, the peak of local contractile forces by CUs scales with rigidity. The cytoskeletal protein α-actinin is shared between these two force-producing systems. It initially localizes to the CUs and subsequently moves inward with the actin flow. Knockdown of α-actinin causes aberrant rigidity sensing, loss of CUs, loss of protrusion-retraction cycles, and, surprisingly, enables the cells to proliferate on soft matrices. We present a model based on these results in which local CUs drive rigidity sensing and adhesion formation.
Collapse
Affiliation(s)
- Giovanni Meacci
- Department of Biological Sciences, Columbia University, New York, NY 10027 .,Department of Chemical Engineering, Columbia University, New York, NY 10027
| | - Haguy Wolfenson
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Shuaimin Liu
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | | | - Thomas Iskratsch
- Department of Biological Sciences, Columbia University, New York, NY 10027.,Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Anurag Mathur
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Saba Ghassemi
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Nils Gauthier
- Department of Biological Sciences, Columbia University, New York, NY 10027.,Mechanobiology Institute, National University of Singapore, Singapore, 117411
| | - Erdem Tabdanov
- Department of Biomedical Engineering, Columbia University, New York, NY 10027
| | - James Lohner
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | | | - Ashok C Chander
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Pere Roca-Cusachs
- Department of Biological Sciences, Columbia University, New York, NY 10027.,Institute for Bioengineering of Catalonia and University of Barcelona, 08028 Barcelona, Spain
| | - Ben O'Shaughnessy
- Department of Chemical Engineering, Columbia University, New York, NY 10027
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Michael P Sheetz
- Department of Biological Sciences, Columbia University, New York, NY 10027 .,Mechanobiology Institute, National University of Singapore, Singapore, 117411
| |
Collapse
|
34
|
Müller C, Pompe T. Distinct impacts of substrate elasticity and ligand affinity on traction force evolution. SOFT MATTER 2016; 12:272-280. [PMID: 26451588 DOI: 10.1039/c5sm01706h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cell adhesion is regulated by the mechanical characteristics of the cell environment. The influences of different parameters of the adhesive substrates are convoluted in the cell response leading to questions on the underlying mechanisms, like biochemical signaling on the level of adhesion molecules, or viscoelastic properties of substrates and cell. By a time-resolved analysis of traction force generation during early cell adhesion, we wanted to elucidate the contributions of substrate mechanics to the adhesion process, in particular the impact of substrate elasticity and the molecular friction of adhesion ligands on the substrate surface. Both parameters were independently adjusted by (i) an elastic polyacrylamide hydrogel of variable crosslinking degree and (ii) a thin polymer coating of the hydrogel surface controlling the affinity (and the correlated substrate-ligand friction) of the adhesion ligand fibronectin. Our analysis showed two sequential regimes of considerable force generation, whose occurrence was found to be independent of substrate properties. The first regime is characterized by spreading of the cell and a succeeding force increase. After spreading cells enter the second regime with saturated forces. Substrate elasticity and viscosity, namely hydrogel elasticity and ligand affinity, were both found to affect the kinetics and absolute levels of traction force quantities. A faster increase and a higher saturation level of traction forces were observed for a higher substrate stiffness and a higher ligand affinity. The results complement recent modeling approaches on the evolution of forces in cell spreading and contribute to a better understanding of the dynamics of cell adhesion on viscoelastic substrates.
Collapse
Affiliation(s)
- Christina Müller
- Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany.
| | - Tilo Pompe
- Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, Johannisallee 21-23, 04103 Leipzig, Germany.
| |
Collapse
|
35
|
Xie X, Aalipour A, Gupta SV, Melosh NA. Determining the Time Window for Dynamic Nanowire Cell Penetration Processes. ACS NANO 2015; 9:11667-77. [PMID: 26554425 DOI: 10.1021/acsnano.5b05498] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nanowire (NW) arrays offer opportunities for parallel, nondestructive intracellular access for biomolecule delivery, intracellular recording, and sensing. Spontaneous cell membrane penetration by vertical nanowires is essential for these applications, yet the time- and geometry-dependent penetration process is still poorly understood. In this work, the dynamic NW-cell interface during cell spreading was examined through experimental cell penetration measurements combined with two mechanical models based on substrate adhesion force or cell traction forces. Penetration was determined by comparing the induced tension at a series of given membrane configurations to the critical membrane failure tension. The adhesion model predicts that penetration occurs within a finite window shortly after initial cell contact and adhesion, while the traction model predicts increasing penetration over a longer period. NW penetration rates determined from a cobalt ion delivery assay are compared to the predicted results from the two models. In addition, the effects of NW geometry and cell properties are systematically evaluated to identify the key factors for penetration.
Collapse
Affiliation(s)
| | | | - Sneha V Gupta
- UCSF School of Pharmacy, Bioengineering and Therapeutic Sciences, University of California, San Francisco , San Francisco, California 94143, United States
| | | |
Collapse
|
36
|
Verkhovsky AB. The mechanisms of spatial and temporal patterning of cell-edge dynamics. Curr Opin Cell Biol 2015; 36:113-21. [PMID: 26432504 DOI: 10.1016/j.ceb.2015.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/11/2015] [Accepted: 09/11/2015] [Indexed: 01/14/2023]
Abstract
Adherent cells migrate and change their shape by means of protrusion and retraction at their edges. When and where these activities occur defines the shape of the cell and the way it moves. Despite a great deal of knowledge about the structural organization, components, and biochemical reactions involved in protrusion and retraction, the origins of their spatial and temporal patterns are still poorly understood. Chemical signaling circuitry is believed to be an important source of patterning, but recent studies highlighted mechanisms based on physical forces, motion, and mechanical feedback.
Collapse
Affiliation(s)
- Alexander B Verkhovsky
- Laboratory of Physics of Living Matter, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| |
Collapse
|
37
|
Webster KD, Ng WP, Fletcher DA. Tensional homeostasis in single fibroblasts. Biophys J 2015; 107:146-55. [PMID: 24988349 DOI: 10.1016/j.bpj.2014.04.051] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/21/2014] [Accepted: 04/28/2014] [Indexed: 01/07/2023] Open
Abstract
Adherent cells generate forces through acto-myosin contraction to move, change shape, and sense the mechanical properties of their environment. They are thought to maintain defined levels of tension with their surroundings despite mechanical perturbations that could change tension, a concept known as tensional homeostasis. Misregulation of tensional homeostasis has been proposed to drive disorganization of tissues and promote progression of diseases such as cancer. However, whether tensional homeostasis operates at the single cell level is unclear. Here, we directly test the ability of single fibroblast cells to regulate tension when subjected to mechanical displacements in the absence of changes to spread area or substrate elasticity. We use a feedback-controlled atomic force microscope to measure and modulate forces and displacements of individual contracting cells as they spread on a fibronectin-patterned atomic-force microscope cantilever and coverslip. We find that the cells reach a steady-state contraction force and height that is insensitive to stiffness changes as they fill the micropatterned areas. Rather than maintaining a constant tension, the fibroblasts altered their contraction force in response to mechanical displacement in a strain-rate-dependent manner, leading to a new and stable steady-state force and height. This response is influenced by overexpression of the actin crosslinker α-actinin, and rheology measurements reveal that changes in cell elasticity are also strain- rate-dependent. Our finding of tensional buffering, rather than homeostasis, allows cells to transition between different tensional states depending on how they are displaced, permitting distinct responses to slow deformations during tissue growth and rapid deformations associated with injury.
Collapse
Affiliation(s)
- Kevin D Webster
- Biophysics Graduate Group, University of California, Berkeley, California; Department of Bioengineering, University of California, Berkeley, California
| | - Win Pin Ng
- Department of Bioengineering, University of California, Berkeley, California; University of California Berkeley/University of California San Francisco Graduate Group in Bioengineering, Berkeley, California
| | - Daniel A Fletcher
- Biophysics Graduate Group, University of California, Berkeley, California; Department of Bioengineering, University of California, Berkeley, California; University of California Berkeley/University of California San Francisco Graduate Group in Bioengineering, Berkeley, California; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.
| |
Collapse
|
38
|
Ruan R, Zou L, Sun S, Liu J, Wen L, Gao D, Ding W. Cell blebbing upon addition of cryoprotectants: a self-protection mechanism. PLoS One 2015; 10:e0125746. [PMID: 25875076 PMCID: PMC4395349 DOI: 10.1371/journal.pone.0125746] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/26/2015] [Indexed: 11/23/2022] Open
Abstract
In this work, the mechanism of cell bleb formation upon the addition of cryoprotectants (CPAs) was investigated, and the role of cell blebs in protecting cells was determined. The results show that after adding CPAs, the hyperosmotic stress results in the breakage of the cortical cytoskeleton and the detachment of the cell membrane from the cortical cytoskeleton, causing the formation of cell blebs. Multiple blebs decrease the intracellular hydrostatic pressure induced by the extracellular hyperosmotic shock and alleviate the osmotic damage to cells, which reduces the cell mortality rate. In the presence of a low concentration of CPAs, cell blebs can effectively protect cells. In contrast, in the presence of a high concentration of CPAs, the protective effect is limited because of severe disruption in the cortical cytoskeleton. To determine the relationship between blebs and the mortality rate of cells, we defined a bleb index and found that the bleb index of 0.065 can be regarded as a reference value for the safe addition of DMSO to HeLa cells. The bleb index can also explain why the stepwise addition of CPAs is better than the single-step addition of CPAs. Moreover, the mechanism of the autophagy of cells induced by the hyperosmotic stress was studied, and the protective effect associated with the autophagy was compared with the effect of the blebbing. The findings reported here elucidate a self-protection mechanism of cells experiencing the hyperosmotic stress in the presence of CPAs, and they provide significant evidence for cell tolerance in the field of cryopreservation.
Collapse
Affiliation(s)
- Renquan Ruan
- Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui 230027, China
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Lili Zou
- Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui 230027, China
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Sijie Sun
- Department of Laboratory Medicine, University of Washington, Seattle, WA, 98195, United States of America
| | - Jing Liu
- Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui 230027, China
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Longping Wen
- School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Dayong Gao
- Department of Mechanical Engineering, University of Washington, Seattle, WA, 98195, United States of America
| | - Weiping Ding
- Center for Biomedical Engineering, University of Science and Technology of China, Hefei, Anhui 230027, China
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, Anhui 230027, China
- * E-mail:
| |
Collapse
|
39
|
Modeling universal dynamics of cell spreading on elastic substrates. Biomech Model Mechanobiol 2015; 14:1265-80. [DOI: 10.1007/s10237-015-0673-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/31/2015] [Indexed: 10/24/2022]
|
40
|
Soiné JRD, Brand CA, Stricker J, Oakes PW, Gardel ML, Schwarz US. Model-based traction force microscopy reveals differential tension in cellular actin bundles. PLoS Comput Biol 2015; 11:e1004076. [PMID: 25748431 PMCID: PMC4352062 DOI: 10.1371/journal.pcbi.1004076] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/08/2014] [Indexed: 01/02/2023] Open
Abstract
Adherent cells use forces at the cell-substrate interface to sense and respond to the physical properties of their environment. These cell forces can be measured with traction force microscopy which inverts the equations of elasticity theory to calculate them from the deformations of soft polymer substrates. We introduce a new type of traction force microscopy that in contrast to traditional methods uses additional image data for cytoskeleton and adhesion structures and a biophysical model to improve the robustness of the inverse procedure and abolishes the need for regularization. We use this method to demonstrate that ventral stress fibers of U2OS-cells are typically under higher mechanical tension than dorsal stress fibers or transverse arcs. Adherent cells respond very sensitively not only to biochemical, but also to physical properties of their environment. For example, it has been shown that stem cell differentiation can be guided by substrate rigidity, which is sensed by cells by actively pulling on their environment with actomyosin-generated forces. A commonly used method to measure cell forces during essential biological processes is traction force microscopy, which uses the deformations of a soft elastic substrate to calculate cell forces. However, the standard setup for traction force microscopy suffers from mathematical limitations in calculating forces from displacements. In order to improve this method, we combine image data and biophysical modelling to arrive at a procedure which is more robust and in addition allows us to make statements about the force distribution not only at the cell-substrate interface, but also inside the cell. Here we demonstrate this approach for the contractility of actin stress fibers, which we investigate experimentally with U2OS-cells and theoretically with an active cable network model.
Collapse
Affiliation(s)
- Jérôme R. D. Soiné
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Christoph A. Brand
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
| | - Jonathan Stricker
- Institute for Biophysical Dynamics, Department of Physics, and The James Franck Institute, University of Chicago, Chicago, United States of America
| | - Patrick W. Oakes
- Institute for Biophysical Dynamics, Department of Physics, and The James Franck Institute, University of Chicago, Chicago, United States of America
| | - Margaret L. Gardel
- Institute for Biophysical Dynamics, Department of Physics, and The James Franck Institute, University of Chicago, Chicago, United States of America
| | - Ulrich S. Schwarz
- Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany
- * E-mail:
| |
Collapse
|
41
|
Compressive stress induces dephosphorylation of the myosin regulatory light chain via RhoA phosphorylation by the adenylyl cyclase/protein kinase A signaling pathway. PLoS One 2015; 10:e0117937. [PMID: 25734240 PMCID: PMC4348516 DOI: 10.1371/journal.pone.0117937] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/05/2015] [Indexed: 01/22/2023] Open
Abstract
Mechanical stress that arises due to deformation of the extracellular matrix (ECM) either stretches or compresses cells. The cellular response to stretching has been actively studied. For example, stretching induces phosphorylation of the myosin regulatory light chain (MRLC) via the RhoA/RhoA-associated protein kinase (ROCK) pathway, resulting in increased cellular tension. In contrast, the effects of compressive stress on cellular functions are not fully resolved. The mechanisms for sensing and differentially responding to stretching and compressive stress are not known. To address these questions, we investigated whether phosphorylation levels of MRLC were affected by compressive stress. Contrary to the response in stretching cells, MRLC was dephosphorylated 5 min after cells were subjected to compressive stress. Compressive loading induced activation of myosin phosphatase mediated via the dephosphorylation of myosin phosphatase targeting subunit 1 (Thr853). Because myosin phosphatase targeting subunit 1 (Thr853) is phosphorylated only by ROCK, compressive loading may have induced inactivation of ROCK. However, GTP-bound RhoA (active form) increased in response to compressive stress. The compression-induced activation of RhoA and inactivation of its effector ROCK are contradictory. This inconsistency was due to phosphorylation of RhoA (Ser188) that reduced affinity of RhoA to ROCK. Treatment with the inhibitor of protein kinase A that phosphorylates RhoA (Ser188) induced suppression of compression-stimulated MRLC dephosphorylation. Incidentally, stretching induced phosphorylation of MRLC, but did not affect phosphorylation levels of RhoA (Ser188). Together, our results suggest that RhoA phosphorylation is an important process for MRLC dephosphorylation by compressive loading, and for distinguishing between stretching and compressing cells.
Collapse
|
42
|
Iskratsch T, Wolfenson H, Sheetz MP. Appreciating force and shape—the rise of mechanotransduction in cell biology. Nat Rev Mol Cell Biol 2014; 15:825-33. [PMID: 25355507 PMCID: PMC9339222 DOI: 10.1038/nrm3903] [Citation(s) in RCA: 540] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Although the shapes of organisms are encoded in their genome, the developmental processes that lead to the final form of vertebrates involve a constant feedback between dynamic mechanical forces, and cell growth and motility. Mechanobiology has emerged as a discipline dedicated to the study of the effects of mechanical forces and geometry on cell growth and motility—for example, during cell-matrix adhesion development—through the signalling process of mechanotransduction.
Collapse
Affiliation(s)
- Thomas Iskratsch
- 1] Department of Biological Sciences, Columbia University, New York 10027, USA. [2]
| | - Haguy Wolfenson
- 1] Department of Biological Sciences, Columbia University, New York 10027, USA. [2]
| | - Michael P Sheetz
- Mechanobiology Institute, National University of Singapore, Singapore 117411, and the Department of Biological Sciences, Columbia University, New York 10027, USA
| |
Collapse
|
43
|
Nisenholz N, Rajendran K, Dang Q, Chen H, Kemkemer R, Krishnan R, Zemel A. Active mechanics and dynamics of cell spreading on elastic substrates. SOFT MATTER 2014; 10:7234-46. [PMID: 25103537 DOI: 10.1039/c4sm00780h] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The spreading area of cells has been shown to play a central role in the determination of cell fate and tissue morphogenesis; however, a clear understanding of how spread cell area is determined is still lacking. The observation that cell area and force generally increase with substrate rigidity suggests that cell area is dictated mechanically, by means of a force-balance between the cell and the substrate. A simple mechanical model, corroborated by experimental measurements of cell area and force is presented to analyze the temporal force balance between the cell and the substrate during spreading. The cell is modeled as a thin elastic disc that is actively pulled by lamellipodia protrusions at the cell front. The essential molecular mechanisms of the motor activity at the cell front, including, actin polymerization, adhesion kinetics, and the actin retrograde flow, are accounted for and used to predict the dynamics of cell spreading on elastic substrates; simple, closed-form expressions for the evolution of cell size and force are derived. Time-resolved, traction force microscopy, combined with measurements of cell area are performed to investigate the simultaneous variations of cell size and force. We find that cell area and force increase simultaneously during spreading but the force develops with an apparent delay relative to the increase in cell area. We demonstrate that this may reflect the strain-stiffening property of the cytoskeleton. We further demonstrate that the radial cell force is a concave function of spreading speed and that this may reflect the strengthening of cell-substrate adhesions during spreading.
Collapse
Affiliation(s)
- Noam Nisenholz
- Institute of Dental Sciences and Fritz Haber Center for Molecular Dynamics, Hebrew University of Jerusalem, 91120, Israel.
| | | | | | | | | | | | | |
Collapse
|
44
|
Hu W, Wehrle-Haller B, Vogel V. Maturation of filopodia shaft adhesions is upregulated by local cycles of lamellipodia advancements and retractions. PLoS One 2014; 9:e107097. [PMID: 25229609 PMCID: PMC4167701 DOI: 10.1371/journal.pone.0107097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/13/2014] [Indexed: 11/19/2022] Open
Abstract
While cell-substrate adhesions that form between the protruding edge of a spreading cell and flat surfaces have been studied extensively, processes that regulate the maturation of filopodia adhesions are far less characterized. Since little is known about how the kinetics of formation or disassembly of filopodia adhesions is regulated upon integration into the lamellum, a kinetic analysis of the formation and disassembly of filopodia adhesions was conducted at the leading edge of β3-integrin-EGFP-expressing rat embryonic fibroblasts spreading on fibronectin-coated glass or on soft polyacrylamide gels. Filopodia β3-integrin adhesions matured only if the lamellipodium in their immediate vicinity showed cyclic protrusions and retractions. Filopodia β3-integrin shaft adhesions elongated rapidly when they were overrun by the advancing lamellipodium. Subsequently and once the lamellipodium stopped its advancement at the distal end of the filopodia β3-integrin adhesion, these β3-integrin shaft adhesions started to grow sidewise and colocalize with the newly assembled circumferential actin stress fibers. In contrast, the suppression of the cyclic protrusions and retractions of the lamellipodium by blocking myosin light chain kinase suppressed the growth of filopodia adhesion and resulted in the premature disassembly of filopodia adhesions. The same failure to stabilize those adhesions was found for the advancing lamellipodium that rapidly overran filopodia shaft adhesions without pausing as seen often during fast cell spreading. In turn, plating cells on soft polyacrylamide gels resulted in a reduction of lamellipodia activity, which was partially restored locally by the presence of filopodia adhesions. Thus filopodia adhesions could also mature and be integrated into the lamellum for fibroblasts on soft polyacrylamide substrates.
Collapse
Affiliation(s)
- Wei Hu
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Bernhard Wehrle-Haller
- Department of Cellular Physiology and Metabolism, University Medical Center, University of Geneva, Geneva, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- * E-mail:
| |
Collapse
|
45
|
Three-dimensional cell body shape dictates the onset of traction force generation and growth of focal adhesions. Proc Natl Acad Sci U S A 2014; 111:13075-80. [PMID: 25157134 DOI: 10.1073/pnas.1411785111] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Cell shape affects proliferation and differentiation, which are processes known to depend on integrin-based focal adhesion (FA) signaling. Because shape results from force balance and FAs are mechanosensitive complexes transmitting tension from the cell structure to its mechanical environment, we investigated the interplay between 3D cell shape, traction forces generated through the cell body, and FA growth during early spreading. Combining measurements of cell-scale normal traction forces with FA monitoring, we show that the cell body contact angle controls the onset of force generation and, subsequently, the initiation of FA growth at the leading edge of the lamella. This suggests that, when the cell body switches from convex to concave, tension in the apical cortex is transmitted to the lamella where force-sensitive FAs start to grow. Along this line, increasing the stiffness resisting cell body contraction led to a decrease of the lag time between force generation and FA growth, indicating mechanical continuity of the cell structure and force transmission from the cell body to the leading edge. Remarkably, the overall normal force per unit area of FA increased with stiffness, and its values were similar to those reported for local tangential forces acting on individual FAs. These results reveal how the 3D cell shape feeds back on its internal organization and how it may control cell fate through FA-based signaling.
Collapse
|
46
|
Iskratsch T, Yu CH, Mathur A, Liu S, Stévenin V, Dwyer J, Hone J, Ehler E, Sheetz M. FHOD1 is needed for directed forces and adhesion maturation during cell spreading and migration. Dev Cell 2014; 27:545-59. [PMID: 24331927 DOI: 10.1016/j.devcel.2013.11.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/19/2013] [Accepted: 11/04/2013] [Indexed: 01/13/2023]
Abstract
Matrix adhesions provide critical signals for cell growth or differentiation. They form through a number of distinct steps that follow integrin binding to matrix ligands. In an early step, integrins form clusters that support actin polymerization by an unknown mechanism. This raises the question of how actin polymerization occurs at the integrin clusters. We report here that a major formin in mouse fibroblasts, FHOD1, is recruited to integrin clusters, resulting in actin assembly. Using cell-spreading assays on lipid bilayers, solid substrates, and high-resolution force-sensing pillar arrays, we find that knockdown of FHOD1 impairs spreading, coordinated application of adhesive force, and adhesion maturation. Finally, we show that targeting of FHOD1 to the integrin sites depends on the direct interaction with Src family kinases and is upstream of the activation by Rho kinase. Thus, our findings provide insights into the mechanisms of cell migration with implications for development and disease.
Collapse
Affiliation(s)
- Thomas Iskratsch
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| | - Cheng-Han Yu
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore
| | - Anurag Mathur
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Shuaimin Liu
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Virginie Stévenin
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Joseph Dwyer
- Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Elisabeth Ehler
- Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Michael Sheetz
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA; Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
| |
Collapse
|
47
|
Multiscale modeling of cell shape from the actin cytoskeleton. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 123:143-67. [PMID: 24560144 DOI: 10.1016/b978-0-12-397897-4.00002-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The actin cytoskeleton is a dynamic structure that constantly undergoes complex reorganization events during many cellular processes. Mathematical models and simulations are powerful tools that can provide insight into the physical mechanisms underlying these processes and make predictions that can be experimentally tested. Representation of the interactions of the actin filaments with the plasma membrane and the movement of the plasma membrane for computation remains a challenge. Here, we provide an overview of the different modeling approaches used to study cytoskeletal dynamics and highlight the differential geometry approach that we have used to implement the interactions between the plasma membrane and the cytoskeleton. Using cell spreading as an example, we demonstrate how this approach is able to successfully capture in simulations, experimentally observed behavior. We provide a perspective on how the differential geometry approach can be used for other biological processes.
Collapse
|
48
|
Pu X, Ma C, Yin G, You F, Wei Y. Cell adhesion and invasion inhibitory effect of an ovarian cancer targeting peptide selected via phage display in vivo. Biochem Biophys Res Commun 2014; 443:858-63. [DOI: 10.1016/j.bbrc.2013.12.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 12/10/2013] [Indexed: 11/29/2022]
|
49
|
Rangamani P, Lipshtat A, Azeloglu EU, Calizo RC, Hu M, Ghassemi S, Hone J, Scarlata S, Neves SR, Iyengar R. Decoding information in cell shape. Cell 2013; 154:1356-69. [PMID: 24034255 DOI: 10.1016/j.cell.2013.08.026] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 05/30/2013] [Accepted: 08/14/2013] [Indexed: 12/28/2022]
Abstract
Shape is an indicator of cell health. But how is the information in shape decoded? We hypothesize that decoding occurs by modulation of signaling through changes in plasma membrane curvature. Using analytical approaches and numerical simulations, we studied how elongation of cell shape affects plasma membrane signaling. Mathematical analyses reveal transient accumulation of activated receptors at regions of higher curvature with increasing cell eccentricity. This distribution of activated receptors is periodic, following the Mathieu function, and it arises from local imbalance between reaction and diffusion of soluble ligands and receptors in the plane of the membrane. Numerical simulations show that transient microdomains of activated receptors amplify signals to downstream protein kinases. For growth factor receptor pathways, increasing cell eccentricity elevates the levels of activated cytoplasmic Src and nuclear MAPK1,2. These predictions were experimentally validated by changing cellular eccentricity, showing that shape is a locus of retrievable information storage in cells.
Collapse
Affiliation(s)
- Padmini Rangamani
- Department of Pharmacology and Systems Therapeutics and Systems Biology Center, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Kim JS, Lee CH, Su BY, Coulombe PA. Mathematical modeling of the impact of actin and keratin filaments on keratinocyte cell spreading. Biophys J 2013. [PMID: 23199911 DOI: 10.1016/j.bpj.2012.09.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Keratin intermediate filaments (IFs) form cross-linked arrays to fulfill their structural support function in epithelial cells and tissues subjected to external stress. How the cross-linking of keratin IFs impacts the morphology and differentiation of keratinocytes in the epidermis and related surface epithelia remains an open question. Experimental measurements have established that keratinocyte spreading area is inversely correlated to the extent of keratin IF bundling in two-dimensional culture. In an effort to quantitatively explain this relationship, we developed a mathematical model in which isotropic cell spreading is considered as a first approximation. Relevant physical properties such as actin protrusion, adhesion events, and the corresponding response of lamellum formation at the cell periphery are included in this model. Through optimization with experimental data that relate time-dependent changes in keratinocyte surface area during spreading, our simulation results confirm the notion that the organization and mechanical properties of cross-linked keratin filaments affect cell spreading; in addition, our results provide details of the kinetics of this effect. These in silico findings provide further support for the notion that differentiation-related changes in the density and intracellular organization of keratin IFs affect tissue architecture in epidermis and related stratified epithelia.
Collapse
Affiliation(s)
- Jin Seob Kim
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.
| | | | | | | |
Collapse
|