1
|
Wade EM, Goodin EA, Morgan T, Pereira S, Woolley AG, Jenkins ZA, Daniel PB, Robertson SP. The hinge-1 domain of Flna is not necessary for diverse physiological functions in mice. Eur J Clin Invest 2024:e14308. [PMID: 39215762 DOI: 10.1111/eci.14308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 08/19/2024] [Indexed: 09/04/2024]
Abstract
INTRODUCTION The filamins are cytoskeletal binding proteins that dynamically crosslink actin into orthogonal networks or bundle it into stress fibres. The domain structure of filamin proteins is very well characterised, with an N-terminal actin-binding region, followed by 24 immunoglobulin-like repeat units. The repeat domains are separated into distinct segments by two regions of low-complexity known as hinge-1 and hinge-2. The role of hinge-1 especially has been proposed to be essential for protein function as it provides flexibility to the otherwise rigid protein, and is a target for cleavage by calpain. Hinge-1 protects cells from otherwise destructive forces, and the products of calpain cleavage are involved in critical cellular signalling processes, such as survival during hypoxia. Pathogenic variants in FLNA encoding Filamin A, including those that remove the hinge-1 domain, cause a wide range of survivable developmental disorders. In contrast, complete loss of function of this gene is embryonic lethal in human and mouse. METHODS AND RESULTS In this study, we show that removing filamin A hinge-1 from mouse (FlnaΔH1), while preserving its expression level leads to no obvious developmental phenotype. Detailed characterisation of the skeletons of FlnaΔH1 mice showed no skeletal phenotype reminiscent of that found in the FLNA-causing skeletal dysplasia. Furthermore, nuclear functions of FLNA are maintained with loss of Filamin A hinge-1. CONCLUSION We conclude that hinge-1 is dispensable for filamin A protein function during development over the murine lifespan.
Collapse
Affiliation(s)
- Emma M Wade
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Elizabeth A Goodin
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Tim Morgan
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Stephana Pereira
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Adele G Woolley
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Biodiscovery, University of Otago, Dunedin, New Zealand
| | - Zandra A Jenkins
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Philip B Daniel
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| |
Collapse
|
2
|
Katsuta H, Sokabe M, Hirata H. From stress fiber to focal adhesion: a role of actin crosslinkers in force transmission. Front Cell Dev Biol 2024; 12:1444827. [PMID: 39193363 PMCID: PMC11347286 DOI: 10.3389/fcell.2024.1444827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 08/01/2024] [Indexed: 08/29/2024] Open
Abstract
The contractile apparatus, stress fiber (SF), is connected to the cell adhesion machinery, focal adhesion (FA), at the termini of SF. The SF-FA complex is essential for various mechanical activities of cells, including cell adhesion to the extracellular matrix (ECM), ECM rigidity sensing, and cell migration. This mini-review highlights the importance of SF mechanics in these cellular activities. Actin-crosslinking proteins solidify SFs by attenuating myosin-driven flows of actin and myosin filaments within the SF. In the solidified SFs, viscous slippage between actin filaments in SFs and between the filaments and the surrounding cytosol is reduced, leading to efficient transmission of myosin-generated contractile force along the SFs. Hence, SF solidification via actin crosslinking ensures exertion of a large force to FAs, enabling FA maturation, ECM rigidity sensing and cell migration. We further discuss intracellular mechanisms for tuning crosslinker-modulated SF mechanics and the potential relationship between the aberrance of SF mechanics and pathology including cancer.
Collapse
Affiliation(s)
- Hiroki Katsuta
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Masahiro Sokabe
- Human Information Systems Laboratories, Kanazawa Institute of Technology, Hakusan, Japan
| | - Hiroaki Hirata
- Department of Applied Bioscience, Kanazawa Institute of Technology, Hakusan, Japan
| |
Collapse
|
3
|
Wade EM, Morgan T, Gimenez G, Jenkins ZA, Titheradge H, O'Donnell M, Skidmore D, Suri M, Robertson SP. Pathogenic FLNA variants affecting the hinge region of filamin A are associated with male survival. Am J Med Genet A 2024:e63779. [PMID: 38853608 DOI: 10.1002/ajmg.a.63779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 05/07/2024] [Accepted: 05/18/2024] [Indexed: 06/11/2024]
Abstract
Pathogenic variants in FLNA cause a diversity of X-linked developmental disorders associated with either preserved or diminished levels of filamin A protein and are conceptualized dichotomously as relating to underlying gain- or loss-of-function pathogenic mechanisms. Hemizygosity for germline deletions or truncating variants in FLNA is generally considered to result in embryonic lethality. Structurally, filamin A is composed of an N-terminal actin-binding region, followed by 24 immunoglobulin-like repeat units. The repeat domains are separated into distinct segments by two regions of low-complexity known as hinge-1 and hinge-2. Hinge-1 is proposed to confer flexibility to the otherwise rigid protein and is a target for cleavage by calpain with the resultant filamin fragments mediating crucial cellular signaling processes. Here, three families with pathogenic variants in FLNA that impair the function of hinge-1 in males are described, leading to distinct clinical phenotypes. One large in-frame deletion that includes the hinge leads to frontometaphyseal dysplasia in affected males and females, while two germline truncating variants located within the exon encoding hinge 1 result in phenotypes in males that are explained by exon skipping and under-expression of a transcript that deletes hinge-1 from the resultant protein. These three variants affecting hinge-1 indicate that this domain does not mediate cellular functions that, when deficientresult in embryonic lethality in males and that germline truncating variants in this region of FLNA can result in viable phenotypes in males.
Collapse
Affiliation(s)
- Emma M Wade
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Tim Morgan
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Gregory Gimenez
- Department of Pathology, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Zandra A Jenkins
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| | - Hannah Titheradge
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - Marie O'Donnell
- Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK
| | - David Skidmore
- IWK Hospital, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Mohnish Suri
- Clinical Genetics Service, City Hospital, Nottingham, UK
| | - Stephen P Robertson
- Department of Women's and Children's Health, Dunedin School of Medicine, Otago University, Dunedin, New Zealand
| |
Collapse
|
4
|
Karimi A, Aga M, Khan T, D'costa SD, Thaware O, White E, Kelley MJ, Gong H, Acott TS. Comparative analysis of traction forces in normal and glaucomatous trabecular meshwork cells within a 3D, active fluid-structure interaction culture environment. Acta Biomater 2024; 180:206-229. [PMID: 38641184 PMCID: PMC11095374 DOI: 10.1016/j.actbio.2024.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/26/2024] [Accepted: 04/11/2024] [Indexed: 04/21/2024]
Abstract
This study presents a 3D in vitro cell culture model, meticulously 3D printed to replicate the conventional aqueous outflow pathway anatomical structure, facilitating the study of trabecular meshwork (TM) cellular responses under glaucomatous conditions. Glaucoma affects TM cell functionality, leading to extracellular matrix (ECM) stiffening, enhanced cell-ECM adhesion, and obstructed aqueous humor outflow. Our model, reconstructed from polyacrylamide gel with elastic moduli of 1.5 and 21.7 kPa, is based on serial block-face scanning electron microscopy images of the outflow pathway. It allows for quantifying 3D, depth-dependent, dynamic traction forces exerted by both normal and glaucomatous TM cells within an active fluid-structure interaction (FSI) environment. In our experimental design, we designed two scenarios: a control group with TM cells observed over 20 hours without flow (static setting), focusing on intrinsic cellular contractile forces, and a second scenario incorporating active FSI to evaluate its impact on traction forces (dynamic setting). Our observations revealed that active FSI results in higher traction forces (normal: 1.83-fold and glaucoma: 2.24-fold) and shear strains (normal: 1.81-fold and glaucoma: 2.41-fold), with stiffer substrates amplifying this effect. Glaucomatous cells consistently exhibited larger forces than normal cells. Increasing gel stiffness led to enhanced stress fiber formation in TM cells, particularly in glaucomatous cells. Exposure to active FSI dramatically altered actin organization in both normal and glaucomatous TM cells, particularly affecting cortical actin stress fiber arrangement. This model while preliminary offers a new method in understanding TM cell biomechanics and ECM stiffening in glaucoma, highlighting the importance of FSI in these processes. STATEMENT OF SIGNIFICANCE: This pioneering project presents an advanced 3D in vitro model, meticulously replicating the human trabecular meshwork's anatomy for glaucoma research. It enables precise quantification of cellular forces in a dynamic fluid-structure interaction, a leap forward from existing 2D models. This advancement promises significant insights into trabecular meshwork cell biomechanics and the stiffening of the extracellular matrix in glaucoma, offering potential pathways for innovative treatments. This research is positioned at the forefront of ocular disease study, with implications that extend to broader biomedical applications.
Collapse
Affiliation(s)
- Alireza Karimi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, United States.
| | - Mini Aga
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Taaha Khan
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Siddharth Daniel D'costa
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Omkar Thaware
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, United States
| | - Elizabeth White
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Mary J Kelley
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States; Department Integrative Biosciences, School of Dentistry, Oregon Health & Science University, Portland, OR, United States
| | - Haiyan Gong
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States; Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, United States
| | - Ted S Acott
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States; Department Chemical Physiology & Biochemistry, School of Medicine, Oregon Health & Science University, Portland, OR, United States
| |
Collapse
|
5
|
Karimi A, Aga M, Khan T, D'costa SD, Cardenas-Riumallo S, Zelenitz M, Kelley MJ, Acott TS. Dynamic traction force in trabecular meshwork cells: A 2D culture model for normal and glaucomatous states. Acta Biomater 2024; 175:138-156. [PMID: 38151067 PMCID: PMC10843681 DOI: 10.1016/j.actbio.2023.12.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 12/29/2023]
Abstract
Glaucoma, which is associated with intraocular pressure (IOP) elevation, results in trabecular meshwork (TM) cellular dysfunction, leading to increased rigidity of the extracellular matrix (ECM), larger adhesion forces between the TM cells and ECM, and higher resistance to aqueous humor drainage. TM cells sense the mechanical forces due to IOP dynamic and apply multidimensional forces on the ECM. Recognizing the importance of cellular forces in modulating various cellular activities and development, this study is aimed to develop a 2D in vitro cell culture model to calculate the 3D, depth-dependent, dynamic traction forces, tensile/compressive/shear strain of the normal and glaucomatous human TM cells within a deformable polyacrylamide (PAM) gel substrate. Normal and glaucomatous human TM cells were isolated, cultured, and seeded on top of the PAM gel substrate with embedded FluoSpheres, spanning elastic moduli of 1.5 to 80 kPa. Sixteen-hour post-seeding live confocal microscopy in an incubator was conducted to Z-stack image the 3D displacement map of the FluoSpheres within the PAM gels. Combined with the known PAM gel stiffness, we ascertained the 3D traction forces in the gel. Our results revealed meaningfully larger traction forces in the glaucomatous TM cells compared to the normal TM cells, reaching depths greater than 10-µm in the PAM gel substrate. Stress fibers in TM cells increased with gel rigidity, but diminished when stiffness rose from 20 to 80 kPa. The developed 2D cell culture model aids in understanding how altered mechanical properties in glaucoma impact TM cell behavior and aqueous humor outflow resistance. STATEMENT OF SIGNIFICANCE: Glaucoma, a leading cause of irreversible blindness, is intricately linked to elevated intraocular pressures and their subsequent cellular effects. The trabecular meshwork plays a pivotal role in this mechanism, particularly its interaction with the extracellular matrix. This research unveils an advanced 2D in vitro cell culture model that intricately maps the complex 3D forces exerted by trabecular meshwork cells on the extracellular matrix, offering unparalleled insights into the cellular biomechanics at play in both healthy and glaucomatous eyes. By discerning the changes in these forces across varying substrate stiffness levels, we bridge the gap in understanding between cellular mechanobiology and the onset of glaucoma. The findings stand as a beacon for potential therapeutic avenues, emphasizing the gravity of cellular/extracellular matrix interactions in glaucoma's pathogenesis and setting the stage for targeted interventions in its early stages.
Collapse
Affiliation(s)
- Alireza Karimi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.
| | - Mini Aga
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Taaha Khan
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Siddharth Daniel D'costa
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | | | - Meadow Zelenitz
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Mary J Kelley
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA; Department Integrative Biosciences, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - Ted S Acott
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA; Department Chemical Physiology & Biochemistry, School of Medicine, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
6
|
Krajnik A, Nimmer E, Brazzo JA, Biber JC, Drewes R, Tumenbayar BI, Sullivan A, Pham K, Krug A, Heo Y, Kolega J, Heo SJ, Lee K, Weil BR, Kim DH, Gupte SA, Bae Y. Survivin regulates intracellular stiffness and extracellular matrix production in vascular smooth muscle cells. APL Bioeng 2023; 7:046104. [PMID: 37868708 PMCID: PMC10590228 DOI: 10.1063/5.0157549] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/05/2023] [Indexed: 10/24/2023] Open
Abstract
Vascular dysfunction is a common cause of cardiovascular diseases characterized by the narrowing and stiffening of arteries, such as atherosclerosis, restenosis, and hypertension. Arterial narrowing results from the aberrant proliferation of vascular smooth muscle cells (VSMCs) and their increased synthesis and deposition of extracellular matrix (ECM) proteins. These, in turn, are modulated by arterial stiffness, but the mechanism for this is not fully understood. We found that survivin is an important regulator of stiffness-mediated ECM synthesis and intracellular stiffness in VSMCs. Whole-transcriptome analysis and cell culture experiments showed that survivin expression is upregulated in injured femoral arteries in mice and in human VSMCs cultured on stiff fibronectin-coated hydrogels. Suppressed expression of survivin in human VSMCs significantly decreased the stiffness-mediated expression of ECM components related to arterial stiffening, such as collagen-I, fibronectin, and lysyl oxidase. By contrast, expression of these ECM proteins was rescued by ectopic expression of survivin in human VSMCs cultured on soft hydrogels. Interestingly, atomic force microscopy analysis showed that suppressed or ectopic expression of survivin decreases or increases intracellular stiffness, respectively. Furthermore, we observed that inhibiting Rac and Rho reduces survivin expression, elucidating a mechanical pathway connecting intracellular tension, mediated by Rac and Rho, to survivin induction. Finally, we found that survivin inhibition decreases FAK phosphorylation, indicating that survivin-dependent intracellular tension feeds back to maintain signaling through FAK. These findings suggest a novel mechanism by which survivin potentially modulates arterial stiffness.
Collapse
Affiliation(s)
- Amanda Krajnik
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Erik Nimmer
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, New York 14260, USA
| | - Joseph A. Brazzo
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - John C. Biber
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Rhonda Drewes
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Bat-Ider Tumenbayar
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Andra Sullivan
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, New York 14260, USA
| | - Khanh Pham
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Alanna Krug
- Department of Biomedical Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, New York 14260, USA
| | | | - John Kolega
- Department of Pathology and Anatomical Sciences, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Su-Jin Heo
- Department of Orthopedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | - Brian R. Weil
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York 14203, USA
| | - Deok-Ho Kim
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205, USA
| | - Sachin A. Gupte
- Department of Pharmacology, New York Medical College, Valhalla, New York 10595, USA
| | - Yongho Bae
- Author to whom correspondence should be addressed:
| |
Collapse
|
7
|
Shi X, Janmey PA. Large Polyacrylamide Hydrogels for Large-Batch Cell Culture and Mechanobiological Studies. Macromol Biosci 2023; 23:e2300042. [PMID: 37128976 PMCID: PMC10524403 DOI: 10.1002/mabi.202300042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/24/2023] [Indexed: 05/03/2023]
Abstract
The rigidity of a cell's substrate or extracellular matrix plays a vital role in regulating cell and tissue functions. Polyacrylamide (PAAm) hydrogels are one of the most widely used cell culture substrates that provide a physiologically relevant range of stiffness. However, it is still arduous and time-consuming to prepare PAAm substrates in large batches for high-yield or multiscale cell cultures. In this communication, a simple method to prepare PAAm hydrogels with less time cost and easily accessible materials is presented. The hydrogel is mechanically uniform and supports cell culture in a large batch. It is further shown that the stiffness of the hydrogel covers a large range of Young's modulus and is sensed by cells, regulating various cell features including changes in cell morphology, proliferation, and contractility. This method improves the reproducibility of mechanobiology studies and can be easily applied for mechanobiology research requiring large numbers of cells or experimental groups.
Collapse
Affiliation(s)
- Xuechen Shi
- Institute for Medicine and Engineering and Department of Physiology, University of Pennsylvania, Philadelphia, 19104, USA
| | - Paul A Janmey
- Institute for Medicine and Engineering and Department of Physiology, University of Pennsylvania, Philadelphia, 19104, USA
| |
Collapse
|
8
|
Argentati C, Morena F, Guidotti G, Soccio M, Lotti N, Martino S. Tight Regulation of Mechanotransducer Proteins Distinguishes the Response of Adult Multipotent Mesenchymal Cells on PBCE-Derivative Polymer Films with Different Hydrophilicity and Stiffness. Cells 2023; 12:1746. [PMID: 37443780 PMCID: PMC10341130 DOI: 10.3390/cells12131746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/23/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Mechanotransduction is a molecular process by which cells translate physical stimuli exerted by the external environment into biochemical pathways to orchestrate the cellular shape and function. Even with the advancements in the field, the molecular events leading to the signal cascade are still unclear. The current biotechnology of tissue engineering offers the opportunity to study in vitro the effect of the physical stimuli exerted by biomaterial on stem cells and the mechanotransduction pathway involved in the process. Here, we cultured multipotent human mesenchymal/stromal cells (hMSCs) isolated from bone marrow (hBM-MSCs) and adipose tissue (hASCs) on films of poly(butylene 1,4-cyclohexane dicarboxylate) (PBCE) and a PBCE-based copolymer containing 50 mol% of butylene diglycolate co-units (BDG50), to intentionally tune the surface hydrophilicity and the stiffness (PBCE = 560 Mpa; BDG50 = 94 MPa). We demonstrated the activated distinctive mechanotransduction pathways, resulting in the acquisition of an elongated shape in hBM-MSCs on the BDG50 film and in maintaining the canonical morphology on the PBCE film. Notably, hASCs acquired a new, elongated morphology on both the PBCE and BDG50 films. We found that these events were mainly due to the differences in the expression of Cofilin1, Vimentin, Filamin A, and Talin, which established highly sensitive machinery by which, rather than hASCs, hBM-MSCs distinguished PBCE from BDG50 films.
Collapse
Affiliation(s)
- Chiara Argentati
- Department of Chemistry, Biology and Biotechnology, Biochemical and Biotechnological Sciences, University of Perugia, 06122 Perugia, Italy; (C.A.); (F.M.)
| | - Francesco Morena
- Department of Chemistry, Biology and Biotechnology, Biochemical and Biotechnological Sciences, University of Perugia, 06122 Perugia, Italy; (C.A.); (F.M.)
| | - Giulia Guidotti
- Civil, Chemical, Environmental and Materials Engineering Department, University of Bologna, 40131 Bologna, Italy; (G.G.); (M.S.)
| | - Michelina Soccio
- Civil, Chemical, Environmental and Materials Engineering Department, University of Bologna, 40131 Bologna, Italy; (G.G.); (M.S.)
- Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials Technology, CIRI-MAM, University of Bologna, 40136 Bologna, Italy
| | - Nadia Lotti
- Civil, Chemical, Environmental and Materials Engineering Department, University of Bologna, 40131 Bologna, Italy; (G.G.); (M.S.)
- Interdepartmental Center for Industrial Research on Advanced Applications in Mechanical Engineering and Materials Technology, CIRI-MAM, University of Bologna, 40136 Bologna, Italy
| | - Sabata Martino
- Department of Chemistry, Biology and Biotechnology, Biochemical and Biotechnological Sciences, University of Perugia, 06122 Perugia, Italy; (C.A.); (F.M.)
- CEMIN (Centro di Eccellenza Materiali Innovativi Nanostrutturali per Applicazioni Chimica Fisiche e Biomediche), University of Perugia, 06123 Perugia, Italy
| |
Collapse
|
9
|
Lekka M. Applicability of atomic force microscopy to determine cancer-related changes in cells. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210346. [PMID: 35909354 DOI: 10.1098/rsta.2021.0346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 02/24/2022] [Indexed: 06/15/2023]
Abstract
The determination of mechanical properties of living cells as an indicator of cancer progression has become possible with the development of local measurement techniques such as atomic force microscopy (AFM). Its most important advantage is a nanoscopic character, implying that very local alterations can be quantified. The results gathered from AFM measurements of various cancers show that, for most cancers, individual cells are characterized by the lower apparent Young's modulus, denoting higher cell deformability. The measured value depends on various factors, like the properties of substrates used for cell growth, force loading rate or indentation depth. Despite this, the results proved the AFM capability to recognize mechanically altered cells. This can significantly impact the development of methodological approaches toward the precise identification of pathological cells. This article is part of the theme issue 'Nanocracks in nature and industry'.
Collapse
Affiliation(s)
- Małgorzata Lekka
- Department of Biophysical Microstructures, Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland
| |
Collapse
|
10
|
How do cells stiffen? Biochem J 2022; 479:1825-1842. [PMID: 36094371 DOI: 10.1042/bcj20210806] [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: 05/11/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022]
Abstract
Cell stiffness is an important characteristic of cells and their response to external stimuli. In this review, we survey methods used to measure cell stiffness, summarize stimuli that alter cell stiffness, and discuss signaling pathways and mechanisms that control cell stiffness. Several pathological states are characterized by changes in cell stiffness, suggesting this property can serve as a potential diagnostic marker or therapeutic target. Therefore, we consider the effect of cell stiffness on signaling and growth processes required for homeostasis and dysfunction in healthy and pathological states. Specifically, the composition and structure of the cell membrane and cytoskeleton are major determinants of cell stiffness, and studies have identified signaling pathways that affect cytoskeletal dynamics both directly and by altered gene expression. We present the results of studies interrogating the effects of biophysical and biochemical stimuli on the cytoskeleton and other cellular components and how these factors determine the stiffness of both individual cells and multicellular structures. Overall, these studies represent an intersection of the fields of polymer physics, protein biochemistry, and mechanics, and identify specific mechanisms involved in mediating cell stiffness that can serve as therapeutic targets.
Collapse
|
11
|
Mechanical Properties of the Extracellular Environment of Human Brain Cells Drive the Effectiveness of Drugs in Fighting Central Nervous System Cancers. Brain Sci 2022; 12:brainsci12070927. [PMID: 35884733 PMCID: PMC9313046 DOI: 10.3390/brainsci12070927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/04/2022] Open
Abstract
The evaluation of nanomechanical properties of tissues in health and disease is of increasing interest to scientists. It has been confirmed that these properties, determined in part by the composition of the extracellular matrix, significantly affect tissue physiology and the biological behavior of cells, mainly in terms of their adhesion, mobility, or ability to mutate. Importantly, pathophysiological changes that determine disease development within the tissue usually result in significant changes in tissue mechanics that might potentially affect the drug efficacy, which is important from the perspective of development of new therapeutics, since most of the currently used in vitro experimental models for drug testing do not account for these properties. Here, we provide a summary of the current understanding of how the mechanical properties of brain tissue change in pathological conditions, and how the activity of the therapeutic agents is linked to this mechanical state.
Collapse
|
12
|
Oxidative Stress, Vascular Endothelium, and the Pathology of Neurodegeneration in Retina. Antioxidants (Basel) 2022; 11:antiox11030543. [PMID: 35326193 PMCID: PMC8944517 DOI: 10.3390/antiox11030543] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress (OS) is an imbalance between free radicals/ROS and antioxidants, which evokes a biological response and is an important risk factor for diseases, in both the cardiovascular system and central nervous system (CNS). The underlying mechanisms driving pathophysiological complications that arise from OS remain largely unclear. The vascular endothelium is emerging as a primary target of excessive glucocorticoid and catecholamine action. Endothelial dysfunction (ED) has been implicated to play a crucial role in the development of neurodegeneration in the CNS. The retina is known as an extension of the CNS. Stress and endothelium dysfunction are suspected to be interlinked and associated with neurodegenerative diseases in the retina as well. In this narrative review, we explore the role of OS-led ED in the retina by focusing on mechanistic links between OS and ED, ED in the pathophysiology of different retinal neurodegenerative conditions, and how a better understanding of the role of endothelial function could lead to new therapeutic approaches for neurodegenerative diseases in the retina.
Collapse
|
13
|
Ho Thanh MT, Grella A, Kole D, Ambady S, Wen Q. Vimentin intermediate filaments modulate cell traction force but not cell sensitivity to substrate stiffness. Cytoskeleton (Hoboken) 2021; 78:293-302. [PMID: 33993652 DOI: 10.1002/cm.21675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/17/2022]
Abstract
The ability of cells to sense and respond to the mechanical stiffness of the surrounding matrix is important to support normal cell function, wound healing, and development. Central to the process of durosensing is the cytoskeleton composed of three classes of filaments: F-actin, microtubules, and intermediate filaments (IFs). Vimentin is an IF protein that contributes significantly to cell mechanics and cell traction force, which is required to probe extracellular matrix. The role of vimentin in how cells sense and respond to the mechanical rigidity of extracellular matrix is largely unclear. To investigate the role of vimentin in durosensing, we knocked down the vimentin expression level in 3T3 fibroblasts using shRNA transfection and measured cellular responses as functions of substrate stiffness. We quantified durosensitivity by the rates at which cell area and traction force change with substrate stiffness. Our results show that that vimentin plays a role in durosensing by modulating traction force and knocking out vimentin did not significantly affect durosensitivity. These results indicate that vimentin may be a redundant component of the machinery that cells use to sense substrate stiffness.
Collapse
Affiliation(s)
- Minh-Tri Ho Thanh
- Physics Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Alexandra Grella
- Biology & Biotechnology Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Denis Kole
- Biology & Biotechnology Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Sakthikumar Ambady
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Qi Wen
- Physics Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA.,Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| |
Collapse
|
14
|
Schofield CL, Rodrigo-Navarro A, Dalby MJ, Van Agtmael T, Salmeron-Sanchez M. Biochemical‐ and Biophysical‐Induced Barriergenesis in the Blood–Brain Barrier: A Review of Barriergenic Factors for Use in In Vitro Models. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202000068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
| | | | - Matthew J. Dalby
- Centre for the Cellular Microenvironment University of Glasgow Glasgow UK
| | - Tom Van Agtmael
- Institute of Cardiovascular and Medical Sciences University of Glasgow Glasgow UK
| | | |
Collapse
|
15
|
Schnauß J, Schmidt BUS, Brazel CB, Dogan S, Losert W, Anderegg U, Käs JA. Influence of hyaluronic acid binding on the actin cortex measured by optical forces. JOURNAL OF BIOPHOTONICS 2020; 13:e201960215. [PMID: 32246559 DOI: 10.1002/jbio.201960215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
Melanoma cells are often surrounded by hyaluronic acid (HA) rich environments, which are considered to promote tumor progression and metastasis. Induced effects in compound materials consisting of cells embedded in an extracellular matrix have been studied, however, alterations of the single cells have never been addressed. Here, we explicitly addressed single cell properties and measured HA-induced biomechanical changes via deformations induced solely by optical forces. With the optical stretcher setup, cells were deformed after culturing them in either the presence or absence of HA revealing the crucial interplay of HA with the CD44 receptor. To assess the role of CD44 in transducing effects of HA, we compared a CD44 expressing variant of the melanoma cell line RPM-MC to its natural CD44-negative counterpart. Our measurements revealed a significant stiffness change, which we attribute to changes of the actin cytoskeleton.
Collapse
Affiliation(s)
- Jörg Schnauß
- Leipzig University, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, Leipzig, Germany
- Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany
| | - B U Sebastian Schmidt
- University of Maryland, Institute for Physical Science and Technology, Physical Sciences Complex, College Park, MD, USA
| | - Christina B Brazel
- Department of Dermatology, Leipzig University, Medical Faculty, Leipzig, Germany
| | - Senol Dogan
- Leipzig University, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, Leipzig, Germany
| | - Wolfgang Losert
- University of Maryland, Institute for Physical Science and Technology, Physical Sciences Complex, College Park, MD, USA
| | - Ulf Anderegg
- Department of Dermatology, Leipzig University, Medical Faculty, Leipzig, Germany
| | - Josef A Käs
- Leipzig University, Faculty of Physics and Earth Sciences, Peter Debye Institute for Soft Matter Physics, Leipzig, Germany
| |
Collapse
|
16
|
Long-Range and Directional Allostery of Actin Filaments Plays Important Roles in Various Cellular Activities. Int J Mol Sci 2020; 21:ijms21093209. [PMID: 32370032 PMCID: PMC7246755 DOI: 10.3390/ijms21093209] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/27/2020] [Accepted: 04/30/2020] [Indexed: 12/18/2022] Open
Abstract
A wide variety of uniquely localized actin-binding proteins (ABPs) are involved in various cellular activities, such as cytokinesis, migration, adhesion, morphogenesis, and intracellular transport. In a micrometer-scale space such as the inside of cells, protein molecules diffuse throughout the cell interior within seconds. In this condition, how can ABPs selectively bind to particular actin filaments when there is an abundance of actin filaments in the cytoplasm? In recent years, several ABPs have been reported to induce cooperative conformational changes to actin filaments allowing structural changes to propagate along the filament cables uni- or bidirectionally, thereby regulating the subsequent binding of ABPs. Such propagation of ABP-induced cooperative conformational changes in actin filaments may be advantageous for the elaborate regulation of cellular activities driven by actin-based machineries in the intracellular space, which is dominated by diffusion. In this review, we focus on long-range allosteric regulation driven by cooperative conformational changes of actin filaments that are evoked by binding of ABPs, and discuss roles of allostery of actin filaments in narrow intracellular spaces.
Collapse
|
17
|
Intracellular nonequilibrium fluctuating stresses indicate how nonlinear cellular mechanical properties adapt to microenvironmental rigidity. Sci Rep 2020; 10:5902. [PMID: 32246074 PMCID: PMC7125211 DOI: 10.1038/s41598-020-62567-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/09/2020] [Indexed: 11/08/2022] Open
Abstract
Living cells are known to be in thermodynamically nonequilibrium, which is largely brought about by intracellular molecular motors. The motors consume chemical energies to generate stresses and reorganize the cytoskeleton for the cell to move and divide. However, since there has been a lack of direct measurements characterizing intracellular stresses, questions remained unanswered on the intricacies of how cells use such stresses to regulate their internal mechanical integrity in different microenvironments. This report describes a new experimental approach by which we reveal an environmental rigidity-dependent intracellular stiffness that increases with intracellular stress - a revelation obtained, surprisingly, from a correlation between the fluctuations in cellular stiffness and that of intracellular stresses. More surprisingly, by varying two distinct parameters, environmental rigidity and motor protein activities, we observe that the stiffness-stress relationship follows the same curve. This finding provides some insight into the intricacies by suggesting that cells can regulate their responses to their mechanical microenvironment by adjusting their intracellular stress.
Collapse
|
18
|
Repair of Rotator Cuff Tendon Defects in Aged Rats Using a Growth Factor Injectable Gel Scaffold. Arthroscopy 2020; 36:629-637. [PMID: 31784364 DOI: 10.1016/j.arthro.2019.09.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE To determine if the tendon-specific crosslinking gelatin (Col-Tgel) impregnated with growth factors promotes tendon healing at the bone interface and in a tendon window model. METHODS Two different Col-Tgel formulations were first tested in vitro by evaluating cell morphology and tendogenic differentiation. After the optimum formulation was determined, the gel was mixed with either transforming growth factor-β3 (TGF-β3) or growth differentiation factor-7 (GDF-7) growth factor and prepared for injections. Window defects were induced in 12 animals, which were randomized into the following treatments: (1) sham, (2) empty Col-Tgel, (3) Col-Tgel containing TGF-β3, or (4) Col-Tgel containing GDF-7. Based on these results, the sham, empty Col-Tgel, and Col-Tgel containing TGF-β3 were applied to the supraspinatus repair interface. Tendons were analyzed biomechanically and histologically using hematoxylin and eosin and Masson's trichrome staining. RESULTS In the window defect model, histologic scores were the best in rats treated with TGF-β3 containing Col-Tgel, followed by the empty Col-Tgel scaffold, and finally the sham control. The GDF-7 Col-Tgel was not further tested because occasional ectopic cartilage and bone formation was found in the prior window defect model. In the supraspinatus repair model, there was no statistical difference (P > .05) in the biomechanical strength among the 3 treatment groups, but load-to-failure ratio improved when TGF-β3 was added to the scaffold, suggesting improved tendon healing. CONCLUSIONS This pilot study evaluated the performance of an injectable gel tendon graft in a population of retired breeder rats. The results suggest that Col-Tgel containing TGF-β3 may be a useful adjunctive treatment for surgical repair of full-thickness rotator cuff tears. Histologic and biomechanical scores suggest that Col-Tgel containing TGF-β3 promotes tendon healing. CLINICAL RELEVANCE The results of this study suggest that shoulders injected with Col-Tgel may be a useful adjunctive treatment for repair of rotator cuff tears.
Collapse
|
19
|
Mandal K, Gong Z, Rylander A, Shenoy VB, Janmey PA. Opposite responses of normal hepatocytes and hepatocellular carcinoma cells to substrate viscoelasticity. Biomater Sci 2020; 8:1316-1328. [PMID: 31903466 DOI: 10.1039/c9bm01339c] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The cellular microenvironment plays a critical role in cell differentiation, proliferation, migration, and homeostasis. Recent studies have shown the importance of substrate viscosity in determining cellular function. Here, we study the mechanoresponse of normal hepatocytes and hepatocellular carcinoma cells (HCC) to elastic and viscoelastic substrates using the Huh7 cell line derived from a human liver tumor and primary human hepatocytes (PHH). Unlike PHH and fibroblasts, which respond to viscoelastic substrates by reducing spreading area and actin bundle assembly compared to purely elastic substrates of the same stiffness, Huh7 cells spread faster on viscoelastic substrates than on purely elastic substrates. The steady state spreading areas of Huh7 cells are larger on viscoelastic substrates, whereas the opposite effect occurs with PHH cells. The viscoelasticity of the microenvironment also promotes motility and multiple long protrusions in Huh7 cells. Pharmacologic disruption of the actin assembly makes cells unable to spread on either elastic or viscoelastic substrates. In contrast, upon vimentin perturbation, cells still spread to a limited degree on elastic substrates but are unable to spread on viscoelastic substrates. The time evolution of cell traction force shows that the peak occurs at an earlier time point on viscoelastic substrates compared to elastic substrates. However, the total force generation at steady state is the same on both substrates after 4 hours. Our data suggest that stress relaxation time scales of the viscoelastic substrate regulate cell dynamics and traction force generation, indicating different binding-unbinding rates of the proteins that form cell attachment sites in HCC cells and normal hepatocytes. These results suggest that liver cancer cells may have different characteristic lifetimes of binding to the substrate in comparision to normal cells, which might cause differences in cell spreading and motility within the diseased tissue.
Collapse
Affiliation(s)
- Kalpana Mandal
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia 19104, USA.
| | | | | | | | | |
Collapse
|
20
|
Abstract
Physical stimuli are essential for the function of eukaryotic cells, and changes in physical signals are important elements in normal tissue development as well as in disease initiation and progression. The complexity of physical stimuli and the cellular signals they initiate are as complex as those triggered by chemical signals. One of the most important, and the focus of this review, is the effect of substrate mechanical properties on cell structure and function. The past decade has produced a nearly exponentially increasing number of mechanobiological studies to define how substrate stiffness alters cell biology using both purified systems and intact tissues. Here we attempt to identify common features of mechanosensing in different systems while also highlighting the numerous informative exceptions to what in early studies appeared to be simple rules by which cells respond to mechanical stresses.
Collapse
Affiliation(s)
- Paul A Janmey
- Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Bioengineering, University of California-Berkeley, Berkeley, California; and Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Daniel A Fletcher
- Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Bioengineering, University of California-Berkeley, Berkeley, California; and Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Cynthia A Reinhart-King
- Department of Physiology, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Bioengineering, University of California-Berkeley, Berkeley, California; and Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
| |
Collapse
|
21
|
Lee D, Erickson A, Dudley AT, Ryu S. Mechanical stimulation of growth plate chondrocytes: Previous approaches and future directions. EXPERIMENTAL MECHANICS 2019; 59:1261-1274. [PMID: 31787777 PMCID: PMC6884322 DOI: 10.1007/s11340-018-0424-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Growth plate cartilage resides near the ends of long bones and is the primary driver of skeletal growth. During growth, both intrinsically and extrinsically generated mechanical stresses act on chondrocytes in the growth plate. Although the role of mechanical stresses in promoting tissue growth and homeostasis has been strongly demonstrated in articular cartilage of the major skeletal joints, effects of stresses on growth plate cartilage and bone growth are not as well established. Here, we review the literature on mechanobiology in growth plate cartilage at macroscopic and microscopic scales, with particular emphasis on comparison of results obtained using different methodological approaches, as well as from whole animal and in vitro experiments. To answer these questions, macroscopic mechanical stimulators have been developed and applied to study mechanobiology of growth plate cartilage and chondrocytes. However, the previous approaches have tested a limited number of stress conditions, and the mechanobiology of a single chondrocyte has not been well studied due to limitations of the macroscopic mechanical stimulators. We explore how microfluidics devices can overcome these limitations and improve current understanding of growth plate chondrocyte mechanobiology. In particular, microfluidic devices can generate multiple stress conditions in a single platform and enable real-time monitoring of metabolism and cellular behavior using optical microscopy. Systematic characterization of the chondrocytes using microfluidics will enhance our understanding of how to use mechanical stresses to control the bone growth and the properties of tissue-engineered growth plate cartilage.
Collapse
Affiliation(s)
- D. Lee
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
| | - A. Erickson
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
| | - A. T. Dudley
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
- Corresponding Authors:; Tel: +1-402-559-2820. ; Tel: +1-402-472-4313
| | - S. Ryu
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588
- Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, NE 68588
- Corresponding Authors:; Tel: +1-402-559-2820. ; Tel: +1-402-472-4313
| |
Collapse
|
22
|
Mandal K, Raz-Ben Aroush D, Graber ZT, Wu B, Park CY, Fredberg JJ, Guo W, Baumgart T, Janmey PA. Soft Hyaluronic Gels Promote Cell Spreading, Stress Fibers, Focal Adhesion, and Membrane Tension by Phosphoinositide Signaling, Not Traction Force. ACS NANO 2019; 13:203-214. [PMID: 30500159 PMCID: PMC6511072 DOI: 10.1021/acsnano.8b05286] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Cells respond to both physical and chemical aspects of their substrate. Whether intracellular signals initiated by physical stimuli are fundamentally different from those elicited by chemical stimuli is an open question. Here, we show that the requirement for a stiff substrate (and, therefore, high cellular tension) for cells to produce large focal adhesions and stress fibers is obviated when a soft substrate contains both hyaluronic acid (HA) and an integrin ligand (collagen I). HA is a major extracellular matrix component that is often up-regulated during wound healing and tumor growth. HA, together with collagen I, promotes hepatocellular carcinoma cell (Huh7) spreading on very soft substrates (300 Pa), resulting in morphology and motility similar to what these cells develop only on stiff substrates (>30 kPa) formed by polyacrylamide that contains collagen but not HA. The effect of HA requires turnover of polyphosphoinositides and leads to the activation of Akt. The inhibition of polyphosphoinositide turnover causes Huh7 cells and fibroblasts to decrease spreading and detach, whereas cells on stiffer substrates show almost no response. Traction force microscopy shows that the cell maintains a low strain energy and net contractile moment on HA substrates compared to stiff polyacrylamide substrates. Membrane tension measured by tether pulling is similar on soft HA and stiff polyacrylamide substrates. These results suggest that simultaneous signaling stimulated by HA and an integrin ligand can generate phosphoinositide-mediated signals to the cytoskeleton that reproduce those generated by high cellular tension.
Collapse
Affiliation(s)
| | - Dikla Raz-Ben Aroush
- Kennedy Institute of Rheumatology , University of Oxford , Oxford OX3 7FY , United Kingdom
| | | | | | - Chan Young Park
- School of Public Health , Harvard University , Boston , Massachusetts 02115 , United States
| | - Jeffery J Fredberg
- School of Public Health , Harvard University , Boston , Massachusetts 02115 , United States
| | | | | | | |
Collapse
|
23
|
Schwartz AD, Hall CL, Barney LE, Babbitt CC, Peyton SR. Integrin α 6 and EGFR signaling converge at mechanosensitive calpain 2. Biomaterials 2018; 178:73-82. [PMID: 29909039 PMCID: PMC6211197 DOI: 10.1016/j.biomaterials.2018.05.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/14/2018] [Accepted: 05/31/2018] [Indexed: 11/30/2022]
Abstract
Cells sense and respond to mechanical cues from the extracellular matrix (ECM) via integrins. ECM stiffness is known to enhance integrin clustering and response to epidermal growth factor (EGF), but we lack information on when or if these mechanosensitive growth factor receptors and integrins converge intracellularly. Towards closing this knowledge gap, we combined a biomaterial platform with transcriptomics, molecular biology, and functional assays to link integrin-mediated mechanosensing and epidermal growth factor receptor (EGFR) signaling. We found that high integrin α6 expression controlled breast cancer cell adhesion and motility on soft, laminin-coated substrates, and this mimicked the response of cells to EGF stimulation. The mechanisms that drove both mechanosensitive cell adhesion and motility converged on calpain 2, an intracellular protease important for talin cleavage and focal adhesion turnover. EGF stimulation enhanced adhesion and motility on soft substrates, but required integrin α6 and calpain 2 signaling. In sum, we identified a new role for integrin α6 mechanosensing in breast cancer, wherein cell adhesion to laminin on soft substrates mimicked EGF stimulation. We identified calpain 2, downstream of both integrin α6 engagement and EGFR phosphorylation, as a common intracellular signaling node, and implicate integrin α6 and calpain 2 as potential targets to inhibit the migration of cancer cells in stiff tumor environments.
Collapse
Affiliation(s)
- A D Schwartz
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - C L Hall
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - L E Barney
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - C C Babbitt
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA
| | - S R Peyton
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
| |
Collapse
|
24
|
Basu S, Sutradhar S, Paul R. Substrate stiffness and mechanical stress due to intercellular cooperativity guides tissue structure. J Theor Biol 2018; 457:124-136. [PMID: 30144408 DOI: 10.1016/j.jtbi.2018.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 07/30/2018] [Accepted: 08/01/2018] [Indexed: 12/31/2022]
Abstract
A key challenge in cell and tissue morphogenesis is to understand how a crucial balance between cell proliferation and apoptosis maintains an evolving tissue structure. These processes are mutually non-exclusive and require stiffness monitoring of the host substrate. Adhered cells actively mechanosense the tension in the extracellular matrix (ECM). They collectively alter self-organization and generate a host of tissue patterns. Using an in silico elastic fiber-network in two dimensions, we simulate cell-ECM composite structures and characterize features of the emerging tissue patterns during successive cell proliferation and apoptosis. Our data reveals that, in general, cell viability is a function of the cell-induced effective ECM stiffness supported by intercellular cooperativity. Translating this into a remodeling tissue, we find that average cell cycle duration in concert with the locally stressed regions of the ECM promote heterogeneous proliferation and apoptosis inducing finger-like protrusions along the tissue periphery - a feature normally observed during tumorigenesis. Further, we find that recovery of a scratch wound is delayed for cells harbored on a compliant or (and) in a highly collagen depleted ECM.
Collapse
Affiliation(s)
- S Basu
- Department of Solid State Physics, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Kolkata, West Bengal 700032, India.
| | - S Sutradhar
- Department of Solid State Physics, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Kolkata, West Bengal 700032, India; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA.
| | - R Paul
- Department of Solid State Physics, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Kolkata, West Bengal 700032, India.
| |
Collapse
|
25
|
Embry AE, Liu Z, Henderson JM, Byfield FJ, Liu L, Yoon J, Wu Z, Cruz K, Moradi S, Gillombardo CB, Hussain RZ, Doelger R, Stuve O, Chang AN, Janmey PA, Bruggeman LA, Miller RT. Similar Biophysical Abnormalities in Glomeruli and Podocytes from Two Distinct Models. J Am Soc Nephrol 2018; 29:1501-1512. [PMID: 29572404 DOI: 10.1681/asn.2017050475] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 02/21/2018] [Indexed: 01/19/2023] Open
Abstract
Background FSGS is a pattern of podocyte injury that leads to loss of glomerular function. Podocytes support other podocytes and glomerular capillary structure, oppose hemodynamic forces, form the slit diaphragm, and have mechanical properties that permit these functions. However, the biophysical characteristics of glomeruli and podocytes in disease remain unclear.Methods Using microindentation, atomic force microscopy, immunofluorescence microscopy, quantitative RT-PCR, and a three-dimensional collagen gel contraction assay, we studied the biophysical and structural properties of glomeruli and podocytes in chronic (Tg26 mice [HIV protein expression]) and acute (protamine administration [cytoskeletal rearrangement]) models of podocyte injury.Results Compared with wild-type glomeruli, Tg26 glomeruli became progressively more deformable with disease progression, despite increased collagen content. Tg26 podocytes had disordered cytoskeletons, markedly abnormal focal adhesions, and weaker adhesion; they failed to respond to mechanical signals and exerted minimal traction force in three-dimensional collagen gels. Protamine treatment had similar but milder effects on glomeruli and podocytes.Conclusions Reduced structural integrity of Tg26 podocytes causes increased deformability of glomerular capillaries and limits the ability of capillaries to counter hemodynamic force, possibly leading to further podocyte injury. Loss of normal podocyte mechanical integrity could injure neighboring podocytes due to the absence of normal biophysical signals required for podocyte maintenance. The severe defects in podocyte mechanical behavior in the Tg26 model may explain why Tg26 glomeruli soften progressively, despite increased collagen deposition, and may be the basis for the rapid course of glomerular diseases associated with severe podocyte injury. In milder injury (protamine), similar processes occur but over a longer time.
Collapse
Affiliation(s)
- Addie E Embry
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Zhenan Liu
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Joel M Henderson
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts
| | - F Jefferson Byfield
- Department of Physiology and Biophysics, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Liping Liu
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Medicine, Dallas Veterans Affairs Medical Center, Dallas, Texas
| | - Joonho Yoon
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Zhenzhen Wu
- Department of Medicine, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Katrina Cruz
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts
| | - Sara Moradi
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts
| | | | - Rihanna Z Hussain
- Department of Neurology, University of Texas Southwestern Medical School, Dallas, Texas; and
| | - Richard Doelger
- Department of Neurology, University of Texas Southwestern Medical School, Dallas, Texas; and
| | - Olaf Stuve
- Department of Neurology, University of Texas Southwestern Medical School, Dallas, Texas; and
| | - Audrey N Chang
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Paul A Janmey
- Department of Physiology and Biophysics, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Leslie A Bruggeman
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - R Tyler Miller
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, Texas; .,Department of Medicine, Dallas Veterans Affairs Medical Center, Dallas, Texas
| |
Collapse
|
26
|
Kandel J, Picard M, Wallace DC, Eckmann DM. Mitochondrial DNA 3243A>G heteroplasmy is associated with changes in cytoskeletal protein expression and cell mechanics. J R Soc Interface 2018; 14:rsif.2017.0071. [PMID: 28592659 DOI: 10.1098/rsif.2017.0071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/09/2017] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial and mechanical alterations in cells have both been shown to be hallmarks of human disease. However, little research has endeavoured to establish connections between these two essential features of cells in both functional and dysfunctional situations. In this work, we hypothesized that a specific genetic alteration in mitochondrial function known to cause human disease would trigger changes in cell mechanics. Using a previously characterized set of mitochondrial cybrid cell lines, we examined the relationship between heteroplasmy for the mitochondrial DNA (mtDNA) 3243A>G mutation, the cell cytoskeleton, and resulting cellular mechanical properties. We found that cells with increasing mitochondrial dysfunction markedly differed from one another in gene expression and protein production of various co-regulated cytoskeletal elements. The intracellular positioning and organization of actin also differed across cell lines. To explore the relationship between these changes and cell mechanics, we then measured cellular mechanical properties using atomic force microscopy and found that cell stiffness correlated with gene expression data for known determinants of cell mechanics, γ-actin, α-actinin and filamin A. This work points towards a mechanism linking mitochondrial genetics to single-cell mechanical properties. The transcriptional and structural regulation of cytoskeletal components by mitochondrial function may explain why energetic and mechanical alterations often coexist in clinical conditions.
Collapse
Affiliation(s)
- Judith Kandel
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Martin Picard
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Douglas C Wallace
- Center for Mitochondrial and Epigenomic Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David M Eckmann
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA .,Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
27
|
Neumann BM, Kenney D, Wen Q, Gericke A. Microfluidic device as a facile in vitro tool to generate and investigate lipid gradients. Chem Phys Lipids 2017; 210:109-121. [PMID: 29102758 DOI: 10.1016/j.chemphyslip.2017.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/05/2017] [Accepted: 10/23/2017] [Indexed: 01/13/2023]
Abstract
This work describes a method that utilizes a microfluidic gradient generator to develop lateral lipid gradients in supported lipid bilayers (SLB). The new methodology provides freedom of choice with respect to the lipid composition of the SLB. In addition, the device has the ability to create a protein or bivalent cation gradient in the aqueous phase above the lipid bilayer which can elicit a gradient specific response in the SLB. To highlight these features we demonstrate that we can create a phosphoinositide gradient on various length scales, ranging from 2mm to 50μm. We further show that a Ca2+ gradient in the aqueous phase above the SLB causes anionic lipid clustering mirroring the cation gradient. We demonstrate this effect for mixed phosphatidylcholine/phosphatidylinositol-4,5-bisphosphate bilayers and fora mixed phosphatidylcholine/phosphatidylserine bilayers. The biomimetic platform can be combined with a Total Internal Reflection Fluorescence (TIRF) microscopy setup, which allows for the convenient observation of the time evolution of the gradient and the interaction of ligands with the lipid bilayer. The method provides unprecedented access to study the dynamics and mechanics of protein-lipid interactions on membranes with micron level gradients, mimicking plasma membrane gradients observed in organisms such as Dictyostelium discodeum and neutrophils.
Collapse
Affiliation(s)
- Brittany M Neumann
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, USA
| | - Devin Kenney
- Bridgewater State University, Department of Chemical Sciences, USA
| | - Qi Wen
- Worcester Polytechnic Institute, Department of Physics, USA
| | - Arne Gericke
- Worcester Polytechnic Institute, Department of Chemistry and Biochemistry, USA.
| |
Collapse
|
28
|
Guo M, Pegoraro AF, Mao A, Zhou EH, Arany PR, Han Y, Burnette DT, Jensen MH, Kasza KE, Moore JR, Mackintosh FC, Fredberg JJ, Mooney DJ, Lippincott-Schwartz J, Weitz DA. Cell volume change through water efflux impacts cell stiffness and stem cell fate. Proc Natl Acad Sci U S A 2017; 114:E8618-E8627. [PMID: 28973866 PMCID: PMC5642688 DOI: 10.1073/pnas.1705179114] [Citation(s) in RCA: 284] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cells alter their mechanical properties in response to their local microenvironment; this plays a role in determining cell function and can even influence stem cell fate. Here, we identify a robust and unified relationship between cell stiffness and cell volume. As a cell spreads on a substrate, its volume decreases, while its stiffness concomitantly increases. We find that both cortical and cytoplasmic cell stiffness scale with volume for numerous perturbations, including varying substrate stiffness, cell spread area, and external osmotic pressure. The reduction of cell volume is a result of water efflux, which leads to a corresponding increase in intracellular molecular crowding. Furthermore, we find that changes in cell volume, and hence stiffness, alter stem-cell differentiation, regardless of the method by which these are induced. These observations reveal a surprising, previously unidentified relationship between cell stiffness and cell volume that strongly influences cell biology.
Collapse
Affiliation(s)
- Ming Guo
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
| | - Adrian F Pegoraro
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
| | - Angelo Mao
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138
| | - Enhua H Zhou
- Harvard T. H. Chan School of Public Health, Boston, MA 02115
| | - Praveen R Arany
- Department of Oral Biology, University at Buffalo, Buffalo, NY 14214
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14214
| | - Yulong Han
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Biomedical Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, China
| | - Dylan T Burnette
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Mikkel H Jensen
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Department of Physics and Astronomy, California State University, Sacramento, CA 95819
| | - Karen E Kasza
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Department of Mechanical Engineering, Columbia University, New York, NY 10027
| | - Jeffrey R Moore
- Department of Biological Sciences, University of Massachusetts at Lowell, Lowell, MA 01854
| | - Frederick C Mackintosh
- Department of Physics and Astronomy, VU University, 1081 HV Amsterdam, The Netherlands
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX 77030
- Center for Theoretical Biophysics, Rice University, Houston, TX 77030
| | | | - David J Mooney
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138
| | | | - David A Weitz
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138;
- Department of Physics, Harvard University, Cambridge, MA 02138
| |
Collapse
|
29
|
Pogoda K, Bucki R, Byfield FJ, Cruz K, Lee T, Marcinkiewicz C, Janmey PA. Soft Substrates Containing Hyaluronan Mimic the Effects of Increased Stiffness on Morphology, Motility, and Proliferation of Glioma Cells. Biomacromolecules 2017; 18:3040-3051. [PMID: 28858529 DOI: 10.1021/acs.biomac.7b00324] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Unlike many other cancer cells that grow in tumors characterized by an abnormally stiff collagen-enriched stroma, glioma cells proliferate and migrate in the much softer environment of the brain, which generally lacks the filamentous protein matrix characteristic of breast, liver, colorectal, and other types of cancer. Glial cell-derived tumors and the cells derived from them are highly heterogeneous and variable in their mechanical properties, their response to treatments, and their properties in vitro. Some glioma samples are stiffer than normal brain when measured ex vivo, but even those that are soft in vitro stiffen after deformation by pressure gradients that arise in the tumor environment in vivo. Such mechanical differences can strongly alter the phenotype of cultured glioma cells. Alternatively, chemical signaling might elicit the same phenotype as increased stiffness by activating intracellular messengers common to both initial stimuli. In this study the responses of three different human glioma cell lines to changes in substrate stiffness are compared with their responses on very soft substrates composed of a combination of hyaluronic acid and a specific integrin ligand, either laminin or collagen I. By quantifying cell morphology, stiffness, motility, proliferation, and secretion of the cytokine IL-8, glioma cell responses to increased stiffness are shown to be nearly identically elicited by substrates containing hyaluronic acid, even in the absence of increased stiffness. PI3-kinase activity was required for the response to hyaluronan but not to stiffness. This outcome suggests that hyaluronic acid can trigger the same cellular response, as can be obtained by mechanical force transduced from a stiff environment, and demonstrates that chemical and mechanical features of the tumor microenvironment can achieve equivalent reactions in cancer cells.
Collapse
Affiliation(s)
- Katarzyna Pogoda
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States.,Institute of Nuclear Physics Polish Academy of Sciences , PL-31342 Krakow, Poland
| | - Robert Bucki
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States.,Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok , 15-222 Bialystok, Poland
| | - Fitzroy J Byfield
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States
| | - Katrina Cruz
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States
| | - Tongkeun Lee
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States
| | - Cezary Marcinkiewicz
- CoE Department of Bioengineering, Temple University , Philadelphia, Pennsylvania 19122, United States
| | - Paul A Janmey
- Institute for Medicine and Engineering, University of Pennsylvania , 3340 Smith Walk, Philadelphia, Pennsylvania 19104, United States.,Department of Physiology, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
30
|
Tokuda EY, Jones CE, Anseth KS. PEG-peptide hydrogels reveal differential effects of matrix microenvironmental cues on melanoma drug sensitivity. Integr Biol (Camb) 2017; 9:76-87. [PMID: 28001152 PMCID: PMC5258768 DOI: 10.1039/c6ib00229c] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Metastatic melanoma is highly drug resistant, though the exact mechanisms of this resistance are not completely understood. One method to study melanoma drug responsiveness in vitro is through the use of multicellular spheroids, which have been found to exhibit decreased drug sensitivity compared to traditional 2D culture on various substrates. Because it is unclear whether dimensionality, cell-matrix interactions, and/or cell-cell contacts may influence melanoma drug responsiveness, we utilized a synthetic PEG-based hydrogel to compare the responses of cells cultured on top of or encapsulated within matrices with the same adhesive ligand density, polymer density, and material properties. We found that depending on the stage of progression at which the melanoma cells were derived, the cells responded differently to PLX4032 treatment, a commercially available melanoma drug. In particular, early stage WM35 cells were insensitive to dimensionality (i.e., 2D versus 3D culture), while metastatic A375 cells exhibited decreased responsiveness in 3D compared to 2D. To further understand the role of the microenvironment in early stage melanoma cells, we tested single WM35 cells and multicellular WM35 spheroids in 3D. The results revealed that the spheroids were similarly sensitive to PLX4032 treatment compared to single cell encapsulations. Collectively, this study implicates the role that 3D microenvironments (i.e., dimensionality) may play in observed melanoma drug responsiveness, and the potential lack of influence of cell-matrix interactions over cell-cell contacts in early stages of melanoma resistance to PLX4032-induced apoptosis.
Collapse
Affiliation(s)
- Emi Y Tokuda
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA. and Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Caitlin E Jones
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA. and Department of Biomedical Engineering, Ohio State University, Columbus, OH 43210, USA
| | - Kristi S Anseth
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO 80309, USA. and Howard Hughes Medical Institute and The BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA
| |
Collapse
|
31
|
Miller RT. Mechanical properties of basement membrane in health and disease. Matrix Biol 2017; 57-58:366-373. [DOI: 10.1016/j.matbio.2016.07.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 07/05/2016] [Accepted: 07/07/2016] [Indexed: 01/06/2023]
|
32
|
Shibata K, Nagasaki A, Adachi H, Uyeda TQP. Actin binding domain of filamin distinguishes posterior from anterior actin filaments in migrating Dictyostelium cells. Biophys Physicobiol 2016; 13:321-331. [PMID: 28409084 PMCID: PMC5283175 DOI: 10.2142/biophysico.13.0_321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/28/2016] [Indexed: 01/20/2023] Open
Abstract
Actin filaments in different parts of a cell interact with specific actin binding proteins (ABPs) and perform different functions in a spatially regulated manner. However, the mechanisms of those spatially-defined interactions have not been fully elucidated. If the structures of actin filaments differ in different parts of a cell, as suggested by previous in vitro structural studies, ABPs may distinguish these structural differences and interact with specific actin filaments in the cell. To test this hypothesis, we followed the translocation of the actin binding domain of filamin (ABDFLN) fused with photoswitchable fluorescent protein (mKikGR) in polarized Dictyostelium cells. When ABDFLN-mKikGR was photoswitched in the middle of a polarized cell, photoswitched ABDFLN-mKikGR rapidly translocated to the rear of the cell, even though actin filaments were abundant in the front. The speed of translocation (>3 μm/s) was much faster than that of the retrograde flow of cortical actin filaments. Rapid translocation of ABDFLN-mKikGR to the rear occurred normally in cells lacking GAPA, the only protein, other than actin, known to bind ABDFLN. We suggest that ABDFLN recognizes a certain feature of actin filaments in the rear of the cell and selectively binds to them, contributing to the posterior localization of filamin.
Collapse
Affiliation(s)
- Keitaro Shibata
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan
| | - Akira Nagasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan
| | - Hiroyuki Adachi
- Department of Biotechnology, University of Tokyo, Bunkyo-Ku, Tokyo 113-8657, Japan
| | - Taro Q P Uyeda
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan.,Department of Physics, Faculty of Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
| |
Collapse
|
33
|
Embry AE, Mohammadi H, Niu X, Liu L, Moe B, Miller-Little WA, Lu CY, Bruggeman LA, McCulloch CA, Janmey PA, Miller RT. Biochemical and Cellular Determinants of Renal Glomerular Elasticity. PLoS One 2016; 11:e0167924. [PMID: 27942003 PMCID: PMC5152842 DOI: 10.1371/journal.pone.0167924] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 11/22/2016] [Indexed: 12/22/2022] Open
Abstract
The elastic properties of renal glomeruli and their capillaries permit them to maintain structural integrity in the presence of variable hemodynamic forces. Measured by micro-indentation, glomeruli have an elastic modulus (E, Young's modulus) of 2.1 kPa, and estimates from glomerular perfusion studies suggest that the E of glomeruli is between 2 and 4 kPa. F-actin depolymerization by latrunculin, inhibition of acto-myosin contractility by blebbistatin, reduction in ATP synthesis, and reduction of the affinity of adhesion proteins by EDTA reduced the glomerular E to 1.26, 1.7, 1.5, and 1.43 kPa, respectively. Actin filament stabilization with jasplakinolide and increasing integrin affinity with Mg2+ increased E to 2.65 and 2.87 kPa, respectively. Alterations in glomerular E are reflected in commensurate changes in F/G actin ratios. Disruption of vimentin intermediate filaments by withaferin A reduced E to 0.92 kPa. The E of decellularized glomeruli was 0.74 kPa, indicating that cellular components of glomeruli have dominant effects on their elasticity. The E of glomerular basement membranes measured by magnetic bead displacement was 2.4 kPa. Podocytes and mesangial cells grown on substrates with E values between 3 and 5 kPa had actin fibers and focal adhesions resembling those of podocytes in vivo. Renal ischemia and ischemia-reperfusion reduced the E of glomeruli to 1.58 kPa. These results show that the E of glomeruli is between 2 and 4 kPa. E of the GBM, 2.4 kPa, is consistent with this value, and is supported by the behavior of podocytes and mesangial cells grown on variable stiffness matrices. The podocyte cytoskeleton contributes the major component to the overall E of glomeruli, and a normal E requires ATP synthesis. The reduction in glomerular E following ischemia and in other diseases indicates that reduced glomerular E is a common feature of many forms of glomerular injury and indicative of an abnormal podocyte cytoskeleton.
Collapse
Affiliation(s)
- Addie E. Embry
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - Hamid Mohammadi
- Center for Matrix Biology, University of Toronto, Toronto, Ontario, Canada
| | - Xinying Niu
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - Liping Liu
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - Borren Moe
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - William A. Miller-Little
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - Christopher Y. Lu
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
| | - Leslie A. Bruggeman
- Nephrology, MetroHealth Medical Center, Case-Western Reserve University, Cleveland, Ohio, United States of America
| | | | - Paul A. Janmey
- Physiology and Biophysics, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - R. Tyler Miller
- Nephrology and Medicine, U.T. Southwestern Medical School, Dallas, Texas, United States of America
- Medicine, Dallas VAMC, Dallas, Texas, United States of America
- * E-mail:
| |
Collapse
|
34
|
Trabecular meshwork stiffness in glaucoma. Exp Eye Res 2016; 158:3-12. [PMID: 27448987 DOI: 10.1016/j.exer.2016.07.011] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 07/15/2016] [Accepted: 07/18/2016] [Indexed: 12/26/2022]
Abstract
Alterations in stiffness of the trabecular meshwork (TM) may play an important role in primary open-angle glaucoma (POAG), the second leading cause of blindness. Specifically, certain data suggest an association between elevated intraocular pressure (IOP) and increased TM stiffness; however, the underlying link between TM stiffness and IOP remains unclear and requires further study. We here first review the literature on TM stiffness measurements, encompassing various species and based on a number of measurement techniques, including direct approaches such as atomic force microscopy (AFM) and uniaxial tension tests, and indirect methods based on a beam deflection model. We also briefly review the effects of several factors that affect TM stiffness, including lysophospholipids, rho-kinase inhibitors, cytoskeletal disrupting agents, dexamethasone (DEX), transforming growth factor-β2 (TGF-β2), nitric oxide (NO) and cellular senescence. We then describe a method we have developed for determining TM stiffness measurement in mice using a cryosection/AFM-based approach, and present preliminary data on TM stiffness in C57BL/6J and CBA/J mouse strains. Finally, we investigate the relationship between TM stiffness and outflow facility between these two strains. The method we have developed shows promise for further direct measurements of mouse TM stiffness, which may be of value in understanding mechanistic relations between outflow facility and TM biomechanical properties.
Collapse
|
35
|
Intrinsic FGF2 and FGF5 promotes angiogenesis of human aortic endothelial cells in 3D microfluidic angiogenesis system. Sci Rep 2016; 6:28832. [PMID: 27357248 PMCID: PMC4928073 DOI: 10.1038/srep28832] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 06/06/2016] [Indexed: 12/29/2022] Open
Abstract
The human body contains different endothelial cell types and differences in their angiogenic potential are poorly understood. We compared the functional angiogenic ability of human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs) using a three-dimensional (3D) microfluidic cell culture system. HAECs and HUVECs exhibited similar cellular characteristics in a 2D culture system; however, in the 3D microfluidic angiogenesis system, HAECs exhibited stronger angiogenic potential than HUVECs. Interestingly, the expression level of fibroblast growth factor (FGF)2 and FGF5 under vascular endothelial growth factor (VEGF)-A stimulation was significantly higher in HAECs than in HUVECs. Moreover, small interfering RNA-mediated knockdown of FGF2 and FGF5 more significantly attenuated vascular sprouting induced from HAECs than HUVECs. Our results suggest that HAECs have greater angiogenic potential through FGF2 and FGF5 upregulation and could be a compatible endothelial cell type to achieve robust angiogenesis.
Collapse
|
36
|
Lin HH, Lin HK, Lin IH, Chiou YW, Chen HW, Liu CY, Harn HIC, Chiu WT, Wang YK, Shen MR, Tang MJ. Mechanical phenotype of cancer cells: cell softening and loss of stiffness sensing. Oncotarget 2016; 6:20946-58. [PMID: 26189182 PMCID: PMC4673241 DOI: 10.18632/oncotarget.4173] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/02/2015] [Indexed: 01/06/2023] Open
Abstract
The stiffness sensing ability is required to respond to the stiffness of the matrix. Here we determined whether normal cells and cancer cells display distinct mechanical phenotypes. Cancer cells were softer than their normal counterparts, regardless of the type of cancer (breast, bladder, cervix, pancreas, or Ha-RasV12-transformed cells). When cultured on matrices of varying stiffness, low stiffness decreased proliferation in normal cells, while cancer cells and transformed cells lost this response. Thus, cancer cells undergo a change in their mechanical phenotype that includes cell softening and loss of stiffness sensing. Caveolin-1, which is suppressed in many tumor cells and in oncogene-transformed cells, regulates the mechanical phenotype. Caveolin-1-upregulated RhoA activity and Y397FAK phosphorylation directed actin cap formation, which was positively correlated with cell elasticity and stiffness sensing in fibroblasts. Ha-RasV12-induced transformation and changes in the mechanical phenotypes were reversed by re-expression of caveolin-1 and mimicked by the suppression of caveolin-1 in normal fibroblasts. This is the first study to describe this novel role for caveolin-1, linking mechanical phenotype to cell transformation. Furthermore, mechanical characteristics may serve as biomarkers for cell transformation.
Collapse
Affiliation(s)
- Hsi-Hui Lin
- Department of Physiology, National Cheng Kung University, Tainan, Taiwan
| | - Hsiu-Kuan Lin
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - I-Hsuan Lin
- Department of Physiology, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Wei Chiou
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Horn-Wei Chen
- Department of Physiology, National Cheng Kung University, Tainan, Taiwan
| | - Ching-Yi Liu
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Hans I-Chen Harn
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Wen-Tai Chiu
- Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Yang-Kao Wang
- Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan
| | - Meng-Ru Shen
- Department of Pharmacology, National Cheng Kung University, Tainan, Taiwan
| | - Ming-Jer Tang
- Department of Physiology, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
37
|
Sato T, Ishii J, Ota Y, Sasaki E, Shibagaki Y, Hattori S. Mammalian target of rapamycin (mTOR) complex 2 regulates filamin A-dependent focal adhesion dynamics and cell migration. Genes Cells 2016; 21:579-93. [DOI: 10.1111/gtc.12366] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/01/2016] [Indexed: 12/23/2022]
Affiliation(s)
- Tatsuhiro Sato
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| | - Junko Ishii
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| | - Yuki Ota
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| | - Eri Sasaki
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| | - Yoshio Shibagaki
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| | - Seisuke Hattori
- Division of Biochemistry; School of Pharmaceutical Sciences; Kitasato University; 5-9-1 Shirokane Minato-ku Tokyo 108-8641 Japan
| |
Collapse
|
38
|
Lownes Urbano R, Morss Clyne A. An inverted dielectrophoretic device for analysis of attached single cell mechanics. LAB ON A CHIP 2016; 16:561-73. [PMID: 26738543 PMCID: PMC4734981 DOI: 10.1039/c5lc01297j] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Dielectrophoresis (DEP), the force induced on a polarizable body by a non-uniform electric field, has been widely used to manipulate single cells in suspension and analyze their stiffness. However, most cell types do not naturally exist in suspension but instead require attachment to the tissue extracellular matrix in vivo. Cells alter their cytoskeletal structure when they attach to a substrate, which impacts cell stiffness. It is therefore critical to be able to measure mechanical properties of cells attached to a substrate. We present a novel inverted quadrupole dielectrophoretic device capable of measuring changes in the mechanics of single cells attached to a micropatterned polyacrylamide gel. The device is positioned over a cell of defined size, a directed DEP pushing force is applied, and cell centroid displacement is dynamically measured by optical microscopy. Using this device, single endothelial cells showed greater centroid displacement in response to applied DEP pushing force following actin cytoskeleton disruption by cytochalasin D. In addition, transformed mammary epithelial cell (MCF10A-NeuT) showed greater centroid displacement in response to applied DEP pushing force compared to untransformed cells (MCF10A). DEP device measurements were confirmed by showing that the cells with greater centroid displacement also had a lower elastic modulus by atomic force microscopy. The current study demonstrates that an inverted DEP device can determine changes in single attached cell mechanics on varied substrates.
Collapse
Affiliation(s)
- Rebecca Lownes Urbano
- Drexel University, Department of Mechanical Engineering and Mechanics, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | - Alisa Morss Clyne
- Drexel University, Department of Mechanical Engineering and Mechanics, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| |
Collapse
|
39
|
Krebs K, Ruusmann A, Simonlatser G, Velling T. Expression of FLNa in human melanoma cells regulates the function of integrin α1β1 and phosphorylation and localisation of PKB/AKT/ERK1/2 kinases. Eur J Cell Biol 2015; 94:564-75. [PMID: 26572583 DOI: 10.1016/j.ejcb.2015.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/23/2015] [Accepted: 10/29/2015] [Indexed: 11/20/2022] Open
Abstract
FLNa is a ubiquitous cytoskeletal protein that links transmembrane receptors, including integrins, to F-actin and functions as a signalling intermediate. We investigated FLNa's role in the function of integrin-type collagen receptors, EGF-EGFR signalling and regulation of PKB/Akt and ERK1/2. Using FLNa-deficient M2 human melanoma cells, and same cells expressing EGFP-FLNa (M2F) or its Ig-like repeats 1-8+24, 8-15+24 and 16-24, we found that in M2F and M2 8-15+24 cells, EGF induced the increased phosphorylation of PKB/Akt and ERK1/2. In M2F cells EGF induced the localisation of these kinases to cell nucleus and lamellipodia, respectively, and the ERK1/2 phosphorylation-dependent co-immunoprecipitation of FLNa with ERK1/2. Only M2F and M2 8-15+24 cells adhered to and spread on type I collagen whereas on fibronectin all cells behaved similarly. α1β1 and α2β1 were the integrin-type collagen receptors expressed on these cells with primarily α1β1 localising to focal contacts and affecting cell adhesion and migration in a manner dependent on FLNa or its Ig-like repeats 8-15. Our results suggest a role for FLNa repeats 8-15 in the α1-subunit-dependent regulation of integrin α1β1 function, EGF-EGFR signalling to PKB/Akt and ERK1/2, identify ERK1/2 in EGF-induced FLNa-associated protein complexes, and show that the function of different integrins is subjected to differential regulation by FLNa.
Collapse
Affiliation(s)
- Kristi Krebs
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Anu Ruusmann
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Grethel Simonlatser
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - Teet Velling
- Institute of Gene Technology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| |
Collapse
|
40
|
Abstract
Mechanical stimuli are known to be potent regulators of the form and function of cells and organisms. Although biological regulation has classically been understood in terms of principles from solution biochemistry, advancements in many fields have led to the development of a suite of techniques that are able to reveal the interplay between mechanical loading and changes in the biochemical properties of proteins in systems ranging from single molecules to living organisms. Here, we review these techniques and highlight the emergence of a new molecular-scale understanding of the mechanisms mediating the detection and response of cells to mechanical stimuli, a process termed mechanotransduction. Specifically, we focus on the role of subcellular adhesion structures in sensing the stiffness of the surrounding environment because this process is pertinent to applications in tissue engineering as well the onset of several mechanosensitive disease states, including cancer.
Collapse
Affiliation(s)
- Andrew S LaCroix
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
| | - Katheryn E Rothenberg
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708;
| |
Collapse
|
41
|
Mendez MG, Restle D, Janmey PA. Vimentin enhances cell elastic behavior and protects against compressive stress. Biophys J 2015; 107:314-323. [PMID: 25028873 DOI: 10.1016/j.bpj.2014.04.050] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 04/04/2014] [Accepted: 04/30/2014] [Indexed: 02/05/2023] Open
Abstract
Vimentin intermediate filament expression is a hallmark of epithelial-to-mesenchymal transitions, and vimentin is involved in the maintenance of cell mechanical properties, cell motility, adhesion, and other signaling pathways. A common feature of vimentin-expressing cells is their routine exposure to mechanical stress. Intermediate filaments are unique among cytoskeletal polymers in resisting large deformations in vitro, yet vimentin's mechanical role in the cell is not clearly understood. We use atomic force microscopy to compare the viscoelastic properties of normal and vimentin-null (vim(-/-)) mouse embryo fibroblasts (mEFs) on substrates of different stiffnesses, spread to different areas, and subjected to different compression patterns. In minimally perturbed mEF, vimentin contributes little to the elastic modulus at any indentation depth in cells spread to average areas. On a hard substrate however, the elastic moduli of maximally spread mEFs are greater than those of vim(-/-)mEF. Comparison of the plastic deformation resulting from controlled compression of the cell cortex shows that vimentin's enhancement of elastic behavior increases with substrate stiffness. The elastic moduli of normal mEFs are more stable over time than those of vim(-/-)mEFs when cells are subject to ongoing oscillatory compression, particularly on a soft substrate. In contrast, increasing compressive strain over time shows a greater role for vimentin on a hard substrate. Under both conditions, vim(-/-)mEFs exhibit more variable responses, indicating a loss of regulation. Finally, normal mEFs are more contractile in three-dimensional collagen gels when seeded at low density, when cell-matrix contacts dominate, whereas contractility of vim(-/-)mEF is greater at higher densities when cell-cell contacts are abundant. Addition of fibronectin to gel constructs equalizes the contractility of the two cell types. These results show that the Young's moduli of normal and vim(-/-)mEFs are substrate stiffness dependent even when the spread area is similar, and that vimentin protects against compressive stress and preserves mechanical integrity by enhancing cell elastic behavior.
Collapse
Affiliation(s)
- M G Mendez
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - D Restle
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - P A Janmey
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania.
| |
Collapse
|
42
|
Filamin A Mediates Wound Closure by Promoting Elastic Deformation and Maintenance of Tension in the Collagen Matrix. J Invest Dermatol 2015; 135:2852-2861. [PMID: 26134946 DOI: 10.1038/jid.2015.251] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/29/2015] [Accepted: 06/09/2015] [Indexed: 12/26/2022]
Abstract
Cell-mediated remodeling and wound closure are critical for efficient wound healing, but the contribution of actin-binding proteins to contraction of the extracellular matrix is not defined. We examined the role of filamin A (FLNa), an actin filament cross-linking protein, in wound contraction and maintenance of matrix tension. Conditional deletion of FLNa in fibroblasts in mice was associated with ~4 day delay of full-thickness skin wound contraction compared with wild-type (WT) mice. We modeled the healing wound matrix using cultured fibroblasts plated on grid-supported collagen gels that create lateral boundaries, which are analogues to wound margins. In contrast to WT cells, FLNa knockdown (KD) cells could not completely maintain tension when matrix compaction was resisted by boundaries, which manifested as relaxed matrix tension. Similarly, WT cells on cross-linked collagen, which requires higher levels of sustained tension, exhibited approximately fivefold larger deformation fields and approximately twofold greater fiber alignment compared with FLNa KD cells. Maintenance of boundary-resisted tension markedly influenced the elongation of cell extensions: in WT cells, the number (~50%) and length (~300%) of cell extensions were greater than FLNa KD cells. We conclude that FLNa is required for wound contraction, in part by enabling elastic deformation and maintenance of tension in the matrix.
Collapse
|
43
|
Miller RT, Janmey PA. Relationship of and cross-talk between physical and biologic properties of the glomerulus. Curr Opin Nephrol Hypertens 2015; 24:393-400. [PMID: 26050128 PMCID: PMC4493859 DOI: 10.1097/mnh.0000000000000138] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PURPOSE OF REVIEW Cells and tissues must respond to physical stresses. Cells exist in an elastic environment determined by their matrix, matrix contacts, cell-cell contacts, and cytoskeletal structure. We discuss the determinants of the elastic environment of cells and its potential roles in glomerular disease. RECENT FINDINGS Control of the mechanical environment is sufficient to induce and maintain the differentiated state of cells including myofibroblasts. New experimental techniques permit precise measurement of the elastic characteristics of normal and diseased tissues and cells, and analysis of cell behavior and cytoskeletal structure in response to mechanical and elastic stimuli. Glomeruli become soft early in the course of several disease models, yet late stages are characterized by increased stiffness and fibrosis with loss of organ function. Work in hepatic fibrosis, arterial disease, and oncology demonstrate that increased collagen crosslinking by lysyl oxidase, an early step in the diseases, can result in a sufficient increase in tissue stiffness to alter cell behavior, leading to disease progression. SUMMARY The elastic environment of cells and tissues provides essential signals in development, differentiation, and disease. Identifying the mechanisms that determine the mechanical environment of glomerular cells will complement other approaches to reduce pathologic fibrosis and loss of tissue function.
Collapse
Affiliation(s)
- R. Tyler Miller
- Professor of Medicine, U.T. Southwestern Medical Center, Chief, Medical Service, Dallas VAMC, 4500 S. Lancaster Rd, Dallas, TX 75216, Tel 214-857-0409
| | - Paul A. Janmey
- Professor of Physiology, Physics, and Astronomy, Institute for Medicine and Engineering, University of Pennsylvania, 1010 Vagelos Research Laboratories, 3340 Smith Walk, Philadelphia, PA 19104, 215-573-7380
| |
Collapse
|
44
|
Lyck Hansen M, Beck HC, Irmukhamedov A, Jensen PS, Olsen MH, Rasmussen LM. Proteome analysis of human arterial tissue discloses associations between the vascular content of small leucine-rich repeat proteoglycans and pulse wave velocity. Arterioscler Thromb Vasc Biol 2015; 35:1896-903. [PMID: 26069235 DOI: 10.1161/atvbaha.114.304706] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 05/26/2015] [Indexed: 01/23/2023]
Abstract
OBJECTIVES We hypothesized that arterial stiffness is associated with changes in the arterial protein profile, particularly of extracellular matrix components. We aimed at determining differentially expressed proteins by quantitative proteome analysis in arterial tissue from patients with different degrees of arterial stiffness. APPROACH AND RESULTS Arterial stiffness, assessed by carotid-femoral pulse wave velocity (PWV), central blood pressure and augmentation index by pulse wave analysis were measured the day before surgery in a group of patients undergoing coronary artery bypass grafting. Protein extracts of well-defined, homogenous, nonatherosclerotic individual samples of the left mammary artery from 10 of these patients with high PWV and 9 with low PWV were compared by quantitative proteome analysis, using tandem mass tag labeling and nano-liquid chromatography mass spectrometry/mass spectrometry. Of 418 quantified proteins, 28 were differentially expressed between the groups with high and low PWV (P<0.05). Three of 7 members of the extracellular matrix family of small leucine-rich repeat proteoglycans displayed significant differences between the 2 groups (P=0.0079; Fisher exact test). Three other ECM proteins were differentially regulated, that is, collagen, type VIII, α-1 and α-2 and collagen, type IV, α-1. Several proteins related to smooth muscle cell function and structure were also found in different amounts between the 2 groups. CONCLUSIONS Changes in the arterial amounts of small leucine-rich proteoglycans, known to be involved in collagen fibrillogenesis, and of some nonfibrillar collagens in combination with alterations in proteins related to functions of the human arterial smooth muscle are associated with arterial stiffness, as determined by PWV.
Collapse
Affiliation(s)
- Maria Lyck Hansen
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark.
| | - Hans Christian Beck
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark
| | - Akhmadjon Irmukhamedov
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark
| | - Pia Søndergaard Jensen
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark
| | - Michael Hecht Olsen
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark
| | - Lars Melholt Rasmussen
- From the Department of Clinical Biochemistry and Pharmacology (M.L.H., H.C.B., P.S.J., L.M.R.), Centre of Individualized Medicine In Arterial Diseases (CIMA) (M.L.H., H.C.B., P.S.J., M.H.O., L.M.R.), Department of Cardiothoracic and Vascular Surgery (A.I.), Centre for Clinical Proteomics (H.C.B.), and The Cardiovascular and Metabolic Preventive Clinic, Department of Endocrinology Denmark (M.H.O.), Odense University Hospital, Odense, Denmark
| |
Collapse
|
45
|
Hofmeister LH, Lee SH, Norlander AE, Montaniel KRC, Chen W, Harrison DG, Sung HJ. Phage-display-guided nanocarrier targeting to atheroprone vasculature. ACS NANO 2015; 9:4435-46. [PMID: 25768046 PMCID: PMC4654777 DOI: 10.1021/acsnano.5b01048] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In regions of the circulation where vessels are straight and unbranched, blood flow is laminar and unidirectional. In contrast, at sites of curvature, branch points, and regions distal to stenoses, blood flow becomes disturbed. Atherosclerosis preferentially develops in these regions of disturbed blood flow. Current therapies for atherosclerosis are systemic and may not sufficiently target these atheroprone regions. In this study, we sought to leverage the alterations on the luminal surface of endothelial cells caused by this atheroprone flow for nanocarrier targeting. In vivo phage display was used to discover unique peptides that selectively bind to atheroprone regions in the mouse partial carotid artery ligation model. The peptide GSPREYTSYMPH (PREY) was found to bind 4.5-fold more avidly to the region of disturbed flow and was used to form targeted liposomes. When administered intravenously, PREY-targeted liposomes preferentially accumulated in endothelial cells in the partially occluded carotid artery and other areas of disturbed flow. Proteomic analysis and immunoblotting indicated that fibronectin and Filamin-A were preferentially bound by PREY nanocarriers in vessels with disturbed flow. In additional experiments, PREY nanocarriers were used therapeutically to deliver the nitric oxide synthase cofactor tetrahydrobiopterin (BH4), which we have previously shown to be deficient in regions of disturbed flow. This intervention increased vascular BH4 and reduced vascular superoxide in the partially ligated artery in wild-type mice and reduced plaque burden in the partially ligated left carotid artery of fat fed atheroprone mice (ApoE(-/-)). Targeting atheroprone sites of the circulation with functionalized nanocarriers provides a promising approach for prevention of early atherosclerotic lesion formation.
Collapse
Affiliation(s)
- Lucas H. Hofmeister
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235
| | - Sue H. Lee
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235
| | | | | | - Wei Chen
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37235
| | - David G. Harrison
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235
- Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN, 37235
- Center for Vascular Biology, Vanderbilt University, Nashville, TN, 37235
- Division of Cardiovascular Medicine, Vanderbilt University, Nashville, TN, 37235
| | - Hak-Joon Sung
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235
- Division of Cardiovascular Medicine, Vanderbilt University, Nashville, TN, 37235
| |
Collapse
|
46
|
Stamer WD, Braakman ST, Zhou EH, Ethier CR, Fredberg JJ, Overby DR, Johnson M. Biomechanics of Schlemm's canal endothelium and intraocular pressure reduction. Prog Retin Eye Res 2015; 44:86-98. [PMID: 25223880 PMCID: PMC4268318 DOI: 10.1016/j.preteyeres.2014.08.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 12/29/2022]
Abstract
Ocular hypertension in glaucoma develops due to age-related cellular dysfunction in the conventional outflow tract, resulting in increased resistance to aqueous humor outflow. Two cell types, trabecular meshwork (TM) and Schlemm's canal (SC) endothelia, interact in the juxtacanalicular tissue (JCT) region of the conventional outflow tract to regulate outflow resistance. Unlike endothelial cells lining the systemic vasculature, endothelial cells lining the inner wall of SC support a transcellular pressure gradient in the basal to apical direction, thus acting to push the cells off their basal lamina. The resulting biomechanical strain in SC cells is quite large and is likely to be an important determinant of endothelial barrier function, outflow resistance and intraocular pressure. This review summarizes recent work demonstrating how biomechanical properties of SC cells impact glaucoma. SC cells are highly contractile, and such contraction greatly increases cell stiffness. Elevated cell stiffness in glaucoma may reduce the strain experienced by SC cells, decrease the propensity of SC cells to form pores, and thus impair the egress of aqueous humor from the eye. Furthermore, SC cells are sensitive to the stiffness of their local mechanical microenvironment, altering their own cell stiffness and modulating gene expression in response. Significantly, glaucomatous SC cells appear to be hyper-responsive to substrate stiffness. Thus, evidence suggests that targeting the material properties of SC cells will have therapeutic benefits for lowering intraocular pressure in glaucoma.
Collapse
Affiliation(s)
- W Daniel Stamer
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; Department of Biomedical Engineering, Duke University, Durham, NC, 27710, USA.
| | - Sietse T Braakman
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Enhua H Zhou
- Department of Ophthalmology, Novartis Institutes of BioMedical Research, Cambridge, MA 02139, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA; Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - Jeffrey J Fredberg
- Program in Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, MA 02115, USA; Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA
| | - Darryl R Overby
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Mark Johnson
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, US; Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA; Department of Ophthalmology Engineering, Northwestern University, Chicago, IL, USA
| |
Collapse
|
47
|
Extracellular matrix presentation modulates vascular smooth muscle cell mechanotransduction. Matrix Biol 2014; 41:36-43. [PMID: 25448408 DOI: 10.1016/j.matbio.2014.11.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 01/12/2023]
Abstract
The development of atherosclerosis involves phenotypic changes among vascular smooth muscle cells (VSMCs) that correlate with stiffening and remodeling of the extracellular matrix (ECM). VSMCs are highly sensitive to the composition and mechanical state of the surrounding ECM, and ECM remodeling during atherosclerosis likely contributes to pathology. We hypothesized that ECM mechanics and biochemistry are interdependent in their regulation of VSMC behavior and investigated the effect of ligand presentation on certain stiffness-mediated processes. Our findings demonstrate that substrate stiffening is not a unidirectional stimulus-instead, the influence of mechanics on cell behavior is highly conditioned on ligand biochemistry. This "stiffness-by-ligand" effect was evident for VSMC adhesion, spreading, cytoskeletal polymerization, and focal adhesion assembly, where VSMCs cultured on fibronectin (Fn)-modified substrates showed an augmented response to increasing stiffness, whereas cells on laminin (Ln) substrates showed a dampened response. By contrast, cells on Fn substrates showed a decrease in myosin light chain (MLC) phosphorylation and elongation with increasing stiffness, whereas Ln supported an increase in MLC phosphorylation and no change in cell shape with increasing stiffness. Taken together, these findings show that identical cell populations exhibit opposing responses to substrate stiffening depending on ECM presentation. Our results also suggest that the shift in VSMC phenotype in a developing atherosclerotic lesion is jointly regulated by stromal mechanics and biochemistry. This study highlights the complex influence of the blood vessel wall microenvironment on VSMC phenotype and provides insight into how cells may integrate ECM biochemistry and mechanics during normal and pathological tissue function.
Collapse
|
48
|
Micro-composite substrates for the study of cell-matrix mechanical interactions. J Mech Behav Biomed Mater 2014; 38:232-41. [DOI: 10.1016/j.jmbbm.2014.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 12/03/2013] [Accepted: 01/14/2014] [Indexed: 01/13/2023]
|
49
|
Abstract
Increased flow resistance is responsible for the elevated intraocular pressure characteristic of glaucoma, but the cause of this resistance increase is not known. We tested the hypothesis that altered biomechanical behavior of Schlemm's canal (SC) cells contributes to this dysfunction. We used atomic force microscopy, optical magnetic twisting cytometry, and a unique cell perfusion apparatus to examine cultured endothelial cells isolated from the inner wall of SC of healthy and glaucomatous human eyes. Here we establish the existence of a reduced tendency for pore formation in the glaucomatous SC cell--likely accounting for increased outflow resistance--that positively correlates with elevated subcortical cell stiffness, along with an enhanced sensitivity to the mechanical microenvironment including altered expression of several key genes, particularly connective tissue growth factor. Rather than being seen as a simple mechanical barrier to filtration, the endothelium of SC is seen instead as a dynamic material whose response to mechanical strain leads to pore formation and thereby modulates the resistance to aqueous humor outflow. In the glaucomatous eye, this process becomes impaired. Together, these observations support the idea of SC cell stiffness--and its biomechanical effects on pore formation--as a therapeutic target in glaucoma.
Collapse
|
50
|
Ali MY, Saif MTA. Substrate Stiffness Mediated Metastasis Like Phenotype of Colon Cancer Cells is Independent of Cell to Gel Adhesion. Cell Mol Bioeng 2014. [DOI: 10.1007/s12195-014-0345-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
|