1
|
Zheng Y, Celik U, Vorwald C, Leach JK, Liu GY. High-Resolution Atomic Force Microscopy Investigation of Alginate Hydrogel Materials in Aqueous Media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024. [PMID: 39558643 DOI: 10.1021/acs.langmuir.4c03554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2024]
Abstract
Alginate hydrogels are frequently used in 3D bioprinting and tissue repair and regeneration. Establishing the structure-property-performance correlation of these materials would benefit significantly from high-resolution structural characterization in aqueous environments from the molecular level to continuum. This study overcomes technical challenges and enables high-resolution atomic force microscopy (AFM) imaging of hydrated alginate hydrogels in aqueous media. By combining a new sample preparation protocol with extremely gentle tapping mode AFM imaging, we characterized the morphology and regional mechanical properties of the hydrated alginate. Upon cross-linking, basic units of these hydrogel materials consist of egg-box dimers, which assemble into long fibrils. These fibrils congregate and pile up, forming a sponge-like structure, whose pore size and distribution depend on the cross-linking conditions. At the exterior, surface tension impacts the piling of fibrils, leading to stripe-like features. These structural features contribute to local, regional, and macroscopic mechanics. The outcome provides new insights into its structural characteristics from nanometers to tens of micrometers, i.e., at the dimensions pertaining to biomaterial and hydrogel-cell interactions. Collectively, the results advance our knowledge of the structure and mechanics from the nanometer to continuum, facilitating advanced applications in hydrogel biomaterials.
Collapse
Affiliation(s)
- Yunbo Zheng
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Umit Celik
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Charlotte Vorwald
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
| | - J Kent Leach
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
- Department of Orthopaedic Surgery, UC Davis Health, Sacramento, California 95817, United States
| | - Gang-Yu Liu
- Department of Chemistry, University of California, Davis, California 95616, United States
| |
Collapse
|
2
|
Qiao Q, Song A, An K, Xu N, Jia W, Ruan Y, Bao P, Tao Y, Zhang Y, Wang X, Xu Z. Spontaneously Blinkogenic Probe for Wash-Free Single-Molecule Localization-Based Super-Resolution Imaging in Living Cells. Angew Chem Int Ed Engl 2024:e202417469. [PMID: 39537575 DOI: 10.1002/anie.202417469] [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: 09/11/2024] [Revised: 10/23/2024] [Accepted: 11/13/2024] [Indexed: 11/16/2024]
Abstract
Single-molecule localization super-resolution fluorescence imaging relies on the fluorescence ON/OFF switching of fluorescent probes to break the diffraction limit. However, the unreacted or nonspecifically bound probes cause non-targeted ON/OFF switching, resulting in substantial fluorescence background that significantly reduces localization precision and accuracy. Here, we report a blinkogenic probe HM-DS655-Halo that remains blinking OFF until it binds to HaloTag, thereby triggering its self-blinking activity and enabling its application in direct SMLM imaging in living cells without wash-out steps. We employed the ratio of the duty cycle before and after self-blinking activation, termed as the parameter "RDC" to characterize blinkogenicity. The covalent binding to HaloTag induces HM-DS655-Halo to transition from a fluorescent OFF state to a fluorescence blinking state. This transition also leads to a change in the RDC value, which is calculated to be 12, ensuring super blinkogenicity to effectively suppress background signals in living cells. HM-DS655-Halo was successfully applied in dynamic SMLM imaging of diverse intracellular sub-structures with minimal background noise, including mitochondrial fission and contact, cell migration, and pseudopod growth.
Collapse
Affiliation(s)
- Qinglong Qiao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
| | - Aoxuan Song
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kai An
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ning Xu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
| | - Wenhao Jia
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yiyan Ruan
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pengjun Bao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Tao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yinchan Zhang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiang Wang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
| | - Zhaochao Xu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China
| |
Collapse
|
3
|
Shangguan J, Rock RS. Hundreds of myosin 10s are pushed to the tips of filopodia and could cause traffic jams on actin. eLife 2024; 12:RP90603. [PMID: 39480891 PMCID: PMC11527427 DOI: 10.7554/elife.90603] [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] [Indexed: 11/02/2024] Open
Abstract
Myosin 10 (Myo10) is a motor protein known for its role in filopodia formation. Although Myo10-driven filopodial dynamics have been characterized, there is no information about the absolute number of Myo10 molecules during the filopodial lifecycle. To better understand molecular stoichiometries and packing restraints in filopodia, we measured Myo10 abundance in these structures. We combined SDS-PAGE densitometry with epifluorescence microscopy to quantitate HaloTag-labeled Myo10 in U2OS cells. About 6% of total intracellular Myo10 localizes to filopodia, where it enriches at opposite cellular ends. Hundreds of Myo10s are in a typical filopodium, and their distribution across filopodia is log-normal. Some filopodial tips even contain more Myo10 than accessible binding sites on the actin filament bundle. Live-cell movies reveal a dense cluster of over a hundred Myo10 molecules that initiates filopodial elongation. Hundreds of Myo10 molecules continue to accumulate during filopodial growth, but accumulation ceases when retraction begins. Rates of filopodial elongation, second-phase elongation, and retraction are inversely related to Myo10 quantities. Our estimates of Myo10 molecules in filopodia provide insight into the physics of packing Myo10, its cargo, and other filopodia-associated proteins in narrow membrane compartments. Our protocol provides a framework for future work analyzing Myo10 abundance and distribution upon perturbation.
Collapse
Affiliation(s)
- Julia Shangguan
- Department of Biochemistry and Molecular Biology, University of ChicagoChicagoUnited States
| | - Ronald S Rock
- Department of Biochemistry and Molecular Biology, The Institute for Biophysical Dynamics, University of ChicagoChicagoUnited States
| |
Collapse
|
4
|
Jawahar A, Vermeil J, Heuvingh J, du Roure O, Piel M. The third dimension of the actin cortex. Curr Opin Cell Biol 2024; 89:102381. [PMID: 38905917 DOI: 10.1016/j.ceb.2024.102381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/15/2024] [Accepted: 05/24/2024] [Indexed: 06/23/2024]
Abstract
The actin cortex, commonly described as a thin 2-dimensional layer of actin filaments beneath the plasma membrane, is beginning to be recognized as part of a more dynamic and three-dimensional composite material. In this review, we focus on the elements that contribute to the three-dimensional architecture of the actin cortex. We also argue that actin-rich structures such as filopodia and stress fibers can be viewed as specialized integral parts of the 3D actin cortex. This broadens our definition of the cortex, shifting from its simplified characterization as a thin, two-dimensional layer of actin filaments.
Collapse
Affiliation(s)
- Anumita Jawahar
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France.
| | - Joseph Vermeil
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France; Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
| | - Julien Heuvingh
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Olivia du Roure
- Physique et Mécanique des Milieux Hétérogènes, ESPCI Paris, PSL University, CNRS, Université Paris Cité, Sorbonne Université, Paris, France
| | - Matthieu Piel
- Institut Curie and Institut Pierre Gilles de Gennes, PSL University, CNRS, Paris, France
| |
Collapse
|
5
|
Ruhoff VT, Leijnse N, Doostmohammadi A, Bendix PM. Filopodia: integrating cellular functions with theoretical models. Trends Cell Biol 2024:S0962-8924(24)00113-2. [PMID: 38969554 DOI: 10.1016/j.tcb.2024.05.005] [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: 02/29/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 07/07/2024]
Abstract
Filopodia, widely distributed on cell surfaces, are distinguished by their dynamic extensions, playing pivotal roles in a myriad of biological processes. Their functions span from mechanosensing and guidance to cell-cell communication during cellular organization in the early embryo. Filopodia have significant roles in pathogenic processes, such as cancer invasion and viral dissemination. Molecular mapping of the filopodome has revealed generic components essential for filopodia functions. In parallel, recent insights into biophysical mechanisms governing filopodia dynamics have provided the foundation for broader investigations of filopodia's biological functions. We highlight recent discoveries of engagement of filopodia in various stages of development and pathogenesis and present an overview of intricate molecular and physical features of these cellular structures across a spectrum of cellular activities.
Collapse
Affiliation(s)
| | - Natascha Leijnse
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø, Denmark
| | - Amin Doostmohammadi
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø, Denmark
| | - Poul Martin Bendix
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 København Ø, Denmark.
| |
Collapse
|
6
|
Chikireddy J, Lengagne L, Le Borgne R, Durieu C, Wioland H, Romet-Lemonne G, Jégou A. Fascin-induced bundling protects actin filaments from disassembly by cofilin. J Cell Biol 2024; 223:e202312106. [PMID: 38497788 PMCID: PMC10949937 DOI: 10.1083/jcb.202312106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 03/19/2024] Open
Abstract
Actin filament turnover plays a central role in shaping actin networks, yet the feedback mechanism between network architecture and filament assembly dynamics remains unclear. The activity of ADF/cofilin, the main protein family responsible for filament disassembly, has been mainly studied at the single filament level. This study unveils that fascin, by crosslinking filaments into bundles, strongly slows down filament disassembly by cofilin. We show that this is due to a markedly slower initiation of the first cofilin clusters, which occurs up to 100-fold slower on large bundles compared with single filaments. In contrast, severing at cofilin cluster boundaries is unaffected by fascin bundling. After the formation of an initial cofilin cluster on a filament within a bundle, we observed the local removal of fascin. Notably, the formation of cofilin clusters on adjacent filaments is highly enhanced, locally. We propose that this interfilament cooperativity arises from the local propagation of the cofilin-induced change in helicity from one filament to the other filaments of the bundle. Overall, taking into account all the above reactions, we reveal that fascin crosslinking slows down the disassembly of actin filaments by cofilin. These findings highlight the important role played by crosslinkers in tuning actin network turnover by modulating the activity of other regulatory proteins.
Collapse
Affiliation(s)
| | - Léana Lengagne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Rémi Le Borgne
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Catherine Durieu
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | - Hugo Wioland
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| | | | - Antoine Jégou
- Université Paris Cité, CNRS, Institut Jacques Monod, Paris, France
| |
Collapse
|
7
|
He Z, Liu D, Li H, Gao W, Li X, Ma H, Shi W. Amphiphilic Rhodamine Fluorescent Probes Combined with Basal Imaging for Fine Structures of the Cell Membrane. Anal Chem 2024; 96:7257-7264. [PMID: 38664861 DOI: 10.1021/acs.analchem.4c00946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Confocal fluorescence imaging of fine structures of the cell membrane is important for understanding their biofunctions but is often neglected due to the lack of an effective method. Herein, we develop new amphiphilic rhodamine fluorescent probe RMGs in combination with basal imaging for this purpose. The probes show high signal-to-noise ratio and brightness and low internalization rate, making them suitable for imaging the fine substructures of the cell membrane. Using the representative probe RMG3, we not only observed the cell pseudopodia and intercellular nanotubes but also monitored the formation of migrasomes in real time. More importantly, in-depth imaging studies on more cell lines revealed for the first time that hepatocellular carcinoma cells secreted much more adherent extracellular vesicles than other cell lines, which might serve as a potential indicator of liver cells. We believe that RMGs may be useful for investigating the fine structures of the cell membrane.
Collapse
Affiliation(s)
- Zixu He
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Diankai Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - He Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenjie Gao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaohua Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Huimin Ma
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Shi
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
8
|
An K, Qiao Q, Zhou W, Jiang W, Li J, Xu Z. Stable Super-Resolution Imaging of Cell Membrane Nanoscale Subcompartment Dynamics with a Buffering Cyanine Dye. Anal Chem 2024; 96:5985-5991. [PMID: 38557031 DOI: 10.1021/acs.analchem.4c00342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Super-resolution fluorescence imaging is a crucial method for visualizing the dynamics of the cell membrane involved in various physiological and pathological processes. This requires bright fluorescent dyes with excellent photostability and labeling stability to enable long-term imaging. In this context, we introduce a buffering-strategy-based cyanine dye, SA-Cy5, designed to identify and label carbonic anhydrase IX (CA IX) located in the cell membrane. The unique feature of SA-Cy5 lies in its ability to overcome photobleaching. When the dye on the cell membrane undergoes photobleaching, it is rapidly replaced by an intact probe from the buffer pool outside the cell membrane. This dynamic replacement ensures that the fluorescence intensity on the cell membrane remains stable over time. Under the super-resolution structured illumination microscopy (SIM), the cell membrane can be continuously imaged for 60 min with a time resolution of 20 s. This extended imaging period allows for the observation of substructural dynamics of the cell membrane, including the growth and fusion of filamentous pseudopodia and the fusion of vesicles. Additionally, this buffering strategy introduces a novel approach to address the issue of poor photostability associated with the cyanine dyes.
Collapse
Affiliation(s)
- Kai An
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qinglong Qiao
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Wei Zhou
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Wenchao Jiang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin Li
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Zhaochao Xu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
9
|
Zhao B, Guan D, Liu J, Zhang X, Xiao S, Zhang Y, Smith BD, Liu Q. Squaraine Dyes Exhibit Spontaneous Fluorescence Blinking That Enables Live-Cell Nanoscopy. NANO LETTERS 2024:10.1021/acs.nanolett.4c00595. [PMID: 38588010 PMCID: PMC11458821 DOI: 10.1021/acs.nanolett.4c00595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Hampered by their susceptibility to nucleophilic attack and chemical bleaching, electron-deficient squaraine dyes have long been considered unsuitable for biological imaging. This study unveils a surprising twist: in aqueous environments, bleaching is not irreversible but rather a reversible spontaneous quenching process. Leveraging this new discovery, we introduce a novel deep-red squaraine probe tailored for live-cell super-resolution imaging. This probe enables single-molecule localization microscopy (SMLM) under physiological conditions without harmful additives or intense lasers and exhibits spontaneous blinking orchestrated by biological nucleophiles, such as glutathione or hydroxide anion. With a low duty cycle (∼0.1%) and high-emission rate (∼6 × 104 photons/s under 400 W/cm2), the squaraine probe surpasses the benchmark Cy5 dye by 4-fold and Si-rhodamine by a factor of 1.7 times. Live-cell SMLM with the probe reveals intricate structural details of cell membranes, which demonstrates the high potential of squaraine dyes for next-generation super-resolution imaging.
Collapse
Affiliation(s)
- Bingjie Zhao
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Daoming Guan
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Jinyang Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Xuebo Zhang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Shuzhang Xiao
- Hubei Key Laboratory of Natural Products Research and Development, College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang 443002, Hubei, P. R. China
| | - Yunxiang Zhang
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| | - Bradley D. Smith
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Qian Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200438, China
| |
Collapse
|
10
|
Wilsch-Bräuninger M, Peters J, Huttner WB. High-resolution 3D ultrastructural analysis of developing mouse neocortex reveals long slender processes of endothelial cells that enter neural cells. Front Cell Dev Biol 2024; 12:1344734. [PMID: 38500687 PMCID: PMC10945550 DOI: 10.3389/fcell.2024.1344734] [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: 11/26/2023] [Accepted: 01/31/2024] [Indexed: 03/20/2024] Open
Abstract
The development of the neocortex involves an interplay between neural cells and the vasculature. However, little is known about this interplay at the ultrastructural level. To gain a 3D insight into the ultrastructure of the developing neocortex, we have analyzed the embryonic mouse neocortex by serial block-face scanning electron microscopy (SBF-SEM). In this study, we report a first set of findings that focus on the interaction of blood vessels, notably endothelial tip cells (ETCs), and the neural cells in this tissue. A key observation was that the processes of ETCs, located either in the ventricular zone (VZ) or subventricular zone (SVZ)/intermediate zone (IZ), can enter, traverse the cytoplasm, and even exit via deep plasma membrane invaginations of the host cells, including apical progenitors (APs), basal progenitors (BPs), and newborn neurons. More than half of the ETC processes were found to enter the neural cells. Striking examples of this ETC process "invasion" were (i) protrusions of apical progenitors or newborn basal progenitors into the ventricular lumen that contained an ETC process inside and (ii) ETC process-containing protrusions of neurons that penetrated other neurons. Our observations reveal a - so far unknown - complexity of the ETC-neural cell interaction.
Collapse
Affiliation(s)
| | | | - Wieland B. Huttner
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| |
Collapse
|
11
|
Maxian O, Mogilner A. Helical motors and formins synergize to compact chiral filopodial bundles: A theoretical perspective. Eur J Cell Biol 2024; 103:151383. [PMID: 38237507 DOI: 10.1016/j.ejcb.2023.151383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 12/19/2023] [Accepted: 12/30/2023] [Indexed: 01/28/2024] Open
Abstract
Chiral actin bundles have been shown to play an important role in cell dynamics, but our understanding of the molecular mechanisms which combine to generate chirality remains incomplete. To address this, we numerically simulate a crosslinked filopodial bundle under the actions of helical myosin motors and/or formins and examine the collective buckling and twisting of the actin bundle. We first show that a number of proposed mechanisms to buckle polymerizing actin bundles without motor activity fail under biologically-realistic parameters. We then demonstrate that a simplified model of myosin spinning action at the bundle base effectively "braids" the bundle, but cannot control compaction at the fiber tips. Finally, we show that formin-mediated polymerization and motor activity can act synergitically to compact filopodium bundles, as motor activity bends filaments into shapes that activate twist forces induced by formins. Stochastic fluctuations of actin polymerization rates and slower cross linking dynamics both increase buckling and decrease compaction. We discuss implications of our findings for mechanisms of cytoskeletal chirality.
Collapse
Affiliation(s)
- Ondrej Maxian
- Courant Institute, New York University, New York, NY 10012, USA; Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60615, USA; Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60615, USA
| | - Alex Mogilner
- Courant Institute, New York University, New York, NY 10012, USA; Department of Biology, New York University, New York, NY 10012, USA.
| |
Collapse
|
12
|
Cirilo JA, Liao X, Perrin BJ, Yengo CM. The dynamics of actin protrusions can be controlled by tip-localized myosin motors. J Biol Chem 2024; 300:105516. [PMID: 38042485 PMCID: PMC10801316 DOI: 10.1016/j.jbc.2023.105516] [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: 09/05/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/04/2023] Open
Abstract
Class III myosins localize to inner ear hair cell stereocilia and are thought to be crucial for stereocilia length regulation. Mutations within the motor domain of MYO3A that disrupt its intrinsic motor properties have been associated with non-syndromic hearing loss, suggesting that the motor properties of MYO3A are critical for its function within stereocilia. In this study, we investigated the impact of a MYO3A hearing loss mutation, H442N, using both in vitro motor assays and cell biological studies. Our results demonstrate the mutation causes a dramatic increase in intrinsic motor properties, actin-activated ATPase and in vitro actin gliding velocity, as well as an increase in actin protrusion extension velocity. We propose that both "gain of function" and "loss of function" mutations in MYO3A can impair stereocilia length regulation, which is crucial for stereocilia formation during development and normal hearing. Furthermore, we generated chimeric MYO3A constructs that replace the MYO3A motor and neck domain with the motor and neck domain of other myosins. We found that duty ratio, fraction of ATPase cycle myosin is strongly bound to actin, is a critical motor property that dictates the ability to tip localize within filopodia. In addition, in vitro actin gliding velocities correlated extremely well with filopodial extension velocities over a wide range of gliding and extension velocities. Taken together, our data suggest a model in which tip-localized myosin motors exert force that slides the membrane tip-ward, which can combat membrane tension and enhance the actin polymerization rate that ultimately drives protrusion elongation.
Collapse
Affiliation(s)
- Joseph A Cirilo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Xiayi Liao
- Department of Biology, Indiana University - Purdue University, Indianapolis, Indiana, USA
| | - Benjamin J Perrin
- Department of Biology, Indiana University - Purdue University, Indianapolis, Indiana, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA.
| |
Collapse
|
13
|
Henderson JM, Ljubojevic N, Belian S, Chaze T, Castaneda D, Battistella A, Giai Gianetto Q, Matondo M, Descroix S, Bassereau P, Zurzolo C. Tunnelling nanotube formation is driven by Eps8/IRSp53-dependent linear actin polymerization. EMBO J 2023; 42:e113761. [PMID: 38009333 PMCID: PMC10711657 DOI: 10.15252/embj.2023113761] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 10/27/2023] [Accepted: 11/02/2023] [Indexed: 11/28/2023] Open
Abstract
Tunnelling nanotubes (TNTs) connect distant cells and mediate cargo transfer for intercellular communication in physiological and pathological contexts. How cells generate these actin-mediated protrusions to span lengths beyond those attainable by canonical filopodia remains unknown. Through a combination of micropatterning, microscopy, and optical tweezer-based approaches, we demonstrate that TNTs formed through the outward extension of actin achieve distances greater than the mean length of filopodia and that branched Arp2/3-dependent pathways attenuate the extent to which actin polymerizes in nanotubes, thus limiting their occurrence. Proteomic analysis using epidermal growth factor receptor kinase substrate 8 (Eps8) as a positive effector of TNTs showed that, upon Arp2/3 inhibition, proteins enhancing filament turnover and depolymerization were reduced and Eps8 instead exhibited heightened interactions with the inverted Bin/Amphiphysin/Rvs (I-BAR) domain protein IRSp53 that provides a direct connection with linear actin polymerases. Our data reveals how common protrusion players (Eps8 and IRSp53) form tunnelling nanotubes, and that when competing pathways overutilizing such proteins and monomeric actin in Arp2/3 networks are inhibited, processes promoting linear actin growth dominate to favour tunnelling nanotube formation.
Collapse
Affiliation(s)
- J Michael Henderson
- Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and InfectionCNRS UMR 3691, Université de Paris, Institut PasteurParisFrance
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico‐Chimie CurieParisFrance
- Present address:
Department of ChemistryBowdoin CollegeBrunswickMEUSA
| | - Nina Ljubojevic
- Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and InfectionCNRS UMR 3691, Université de Paris, Institut PasteurParisFrance
- Sorbonne UniversitéParisFrance
| | - Sevan Belian
- Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and InfectionCNRS UMR 3691, Université de Paris, Institut PasteurParisFrance
- Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Thibault Chaze
- Proteomics Platform, Mass Spectrometry for Biology Unit, CNRS USR 2000, Institut PasteurParisFrance
| | - Daryl Castaneda
- Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and InfectionCNRS UMR 3691, Université de Paris, Institut PasteurParisFrance
- Keele UniversityKeeleUK
| | - Aude Battistella
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico‐Chimie CurieParisFrance
| | - Quentin Giai Gianetto
- Proteomics Platform, Mass Spectrometry for Biology Unit, CNRS USR 2000, Institut PasteurParisFrance
- Bioinformatics and Biostatistics Hub, Computational Biology DepartmentCNRS USR 3756, Institut PasteurParisFrance
| | - Mariette Matondo
- Proteomics Platform, Mass Spectrometry for Biology Unit, CNRS USR 2000, Institut PasteurParisFrance
| | - Stéphanie Descroix
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico‐Chimie CurieParisFrance
- Institut Pierre‐Gilles de GennesParisFrance
| | - Patricia Bassereau
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR 168, Laboratoire Physico‐Chimie CurieParisFrance
| | - Chiara Zurzolo
- Membrane Traffic and Pathogenesis Unit, Department of Cell Biology and InfectionCNRS UMR 3691, Université de Paris, Institut PasteurParisFrance
- Department of Molecular Medicine and Medical BiotechnologyUniversity of Naples Federico IINaplesItaly
| |
Collapse
|
14
|
Belian S, Korenkova O, Zurzolo C. Actin-based protrusions at a glance. J Cell Sci 2023; 136:jcs261156. [PMID: 37987375 DOI: 10.1242/jcs.261156] [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] [Indexed: 11/22/2023] Open
Abstract
Actin-based protrusions are at the base of many fundamental cellular processes, such as cell adhesion, migration and intercellular communication. In recent decades, the discovery of new types of actin-based protrusions with unique functions has enriched our comprehension of cellular processes. However, as the repertoire of protrusions continues to expand, the rationale behind the classification of newly identified and previously known structures becomes unclear. Although current nomenclature allows good categorization of protrusions based on their functions, it struggles to distinguish them when it comes to structure, composition or formation mechanisms. In this Cell Science at a Glance article, we discuss the different types of actin-based protrusions, focusing on filopodia, cytonemes and tunneling nanotubes, to help better distinguish and categorize them based on their structural and functional differences and similarities.
Collapse
Affiliation(s)
- Sevan Belian
- Institut Pasteur, Université Paris Cité, CNRS UMR 3691, Membrane Traffic and Pathogenesis, F-75015 Paris, France
- Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - Olga Korenkova
- Institut Pasteur, Université Paris Cité, CNRS UMR 3691, Membrane Traffic and Pathogenesis, F-75015 Paris, France
- Université Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - Chiara Zurzolo
- Institut Pasteur, Université Paris Cité, CNRS UMR 3691, Membrane Traffic and Pathogenesis, F-75015 Paris, France
| |
Collapse
|
15
|
Cheney RE. An unexpected turn for filopodia. Biophys J 2023; 122:3549-3550. [PMID: 37311456 PMCID: PMC10541458 DOI: 10.1016/j.bpj.2023.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/15/2023] Open
Affiliation(s)
- Richard E Cheney
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
| |
Collapse
|
16
|
Jain P, Rimal R, Möller M, Singh S. Topographical influence of electrospun basement membrane mimics on formation of cellular monolayer. Sci Rep 2023; 13:8382. [PMID: 37225757 DOI: 10.1038/s41598-023-34934-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/10/2023] [Indexed: 05/26/2023] Open
Abstract
Functional unit of many organs like lung, kidney, intestine, and eye have their endothelial and epithelial monolayers physically separated by a specialized extracellular matrix called the basement membrane. The intricate and complex topography of this matrix influences cell function, behavior and overall homeostasis. In vitro barrier function replication of such organs requires mimicking of these native features on an artificial scaffold system. Apart from chemical and mechanical features, the choice of nano-scale topography of the artificial scaffold is integral, however its influence on monolayer barrier formation is unclear. Though studies have reported improved single cell adhesion and proliferation in presence of pores or pitted topology, corresponding influence on confluent monolayer formation is not well reported. In this work, basement membrane mimic with secondary topographical cues is developed and its influence on single cells and their monolayers is investigated. We show that single cells cultured on fibers with secondary cues form stronger focal adhesions and undergo increased proliferation. Counterintuitively, absence of secondary cues promoted stronger cell-cell interaction in endothelial monolayers and promoted formation of integral tight barriers in alveolar epithelial monolayers. Overall, this work highlights the importance of choice of scaffold topology to develop basement barrier function in in vitro models.
Collapse
Affiliation(s)
- Puja Jain
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074, Aachen, Germany
| | - Rahul Rimal
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074, Aachen, Germany
- Max Planck Institute for Medical Research (MPImF), Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Martin Möller
- DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074, Aachen, Germany
| | - Smriti Singh
- Max Planck Institute for Medical Research (MPImF), Jahnstrasse 29, 69120, Heidelberg, Germany.
| |
Collapse
|
17
|
The actin bundling activity of ITPKA mainly accounts for its migration-promoting effect in lung cancer cells. Biosci Rep 2023; 43:232487. [PMID: 36688944 PMCID: PMC9912108 DOI: 10.1042/bsr20222150] [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: 10/14/2022] [Revised: 12/29/2022] [Accepted: 01/09/2023] [Indexed: 01/24/2023] Open
Abstract
Expression of Ins(1,4,5)P3-kinase-A (ITPKA), the neuronal isoform of Ins(1,4,5)P3-kinases, is up-regulated in many tumor types. In particular, in lung cancer cells this up-regulation is associated with bad prognosis and it has been shown that a high level of ITPKA increases migration and invasion of lung cancer cell lines. However, since ITPKA exhibits actin bundling and Ins(1,4,5)P3-kinase activity, it was not clear which of these activities account for ITPKA-promoted migration and invasion of cancer cells. To address this issue, we inhibited endogenous actin bundling activity of ITPKA in lung cancer H1299 cells by overexpressing the dominant negative mutant ITPKAL34P. Analysis of actin dynamics in filopodia as well as wound-healing migration revealed that ITPKAL34P inhibited both processes. Moreover, the formation of invasive protrusions into collagen I was strongly blocked in cells overexpressing ITPKAL34P. Furthermore, we found that ATP stimulation slightly but significantly (by 13%) increased migration of cells overexpressing ITPKA while under basal conditions up-regulation of ITPKA had no effect. In accordance with these results, overexpression of a catalytic inactive ITPKA mutant did not affect migration, and the Ins(1,4,5)P3-kinase-inhibitor GNF362 reversed the stimulating effect of ITPKA overexpression on migration. In summary, we demonstrate that under basal conditions the actin bundling activity controls ITPKA-facilitated migration and invasion and in presence of ATP the Ins(1,4,5)P3-kinase activity slightly enhances this effect.
Collapse
|
18
|
Abstract
Actin cytoskeleton force generation, sensing, and adaptation are dictated by the bending and twisting mechanics of filaments. Here, we use magnetic tweezers and microfluidics to twist and pull individual actin filaments and evaluate their response to applied loads. Twisted filaments bend and dissipate torsional strain by adopting a supercoiled plectoneme. Pulling prevents plectoneme formation, which causes twisted filaments to sever. Analysis over a range of twisting and pulling forces and direct visualization of filament and single subunit twisting fluctuations yield an actin filament torsional persistence length of ~10 µm, similar to the bending persistence length. Filament severing by cofilin is driven by local twist strain at boundaries between bare and decorated segments and is accelerated by low pN pulling forces. This work explains how contractile forces generated by myosin motors accelerate filament severing by cofilin and establishes a role for filament twisting in the regulation of actin filament stability and assembly dynamics.
Collapse
|
19
|
Mondal A, Morrison G. Compression-induced buckling of a semiflexible filament in two and three dimensions. J Chem Phys 2022; 157:104903. [DOI: 10.1063/5.0104910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ability of biomolecules to exert forces on their surroundings or resist compression from the environment is essential in a variety of biologically relevant contexts. For filaments in the low-temperature limit and under a constant compressive force, Euler buckling theory predicts a sudden transition from a compressed to a bent state in these slender rods. In this paper, we use a mean-field theory to show that if a semiflexible chain is compressed at a finite temperature with a fixed end-to-end distance (permitting fluctuations in the compressive forces), it exhibits a continuous phase transition to a buckled state at a critical level of compression. We determine a quantitatively accurate prediction of the transverse position distribution function of the midpoint of the chain that indicates this transition. We find the mean compressive forces are non-monotonic as the extension of the filament varies, consistent with the observation that strongly buckled filaments are less able to bear an external load. We also find that for the fixed extension (isometric) ensemble, the buckling transition does not coincide with the local minimum of the mean force (in contrast to Euler buckling). We also show the theory is highly sensitive to fluctuations in length in two dimensions, and that the buckling transition can still be accurately recovered by accounting for those fluctuations. These predictions may be useful in understanding the behavior of filamentous biomolecules compressed by fluctuating forces, relevant in a variety of biological contexts.
Collapse
Affiliation(s)
- Ananya Mondal
- Physics, University of Houston, United States of America
| | - Greg Morrison
- Physics, University of Houston, United States of America
| |
Collapse
|
20
|
Bousgouni V, Inge O, Robertson D, Jones I, Clatworthy I, Bakal C. ARHGEF9 regulates melanoma morphogenesis in environments with diverse geometry and elasticity by promoting filopodial-driven adhesion. iScience 2022; 25:104795. [PMID: 36039362 PMCID: PMC9418690 DOI: 10.1016/j.isci.2022.104795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/27/2022] [Accepted: 07/14/2022] [Indexed: 11/17/2022] Open
Abstract
Rho GTP Exchange Factors (RhoGEFs) and Rho GTPase Activating Proteins (RhoGAPs) are large families of molecules that regulate shape determination in all eukaryotes. In pathologies such as melanoma, RhoGEF and RhoGAP activity underpins the ability of cells to invade tissues of varying elasticity. To identify RhoGEFs and RhoGAPs that regulate melanoma cell shape on soft and/or stiff materials, we performed genetic screens, in tandem with single-cell quantitative morphological analysis. We show that ARHGEF9/Collybistin (Cb) is essential for cell shape determination on both soft and stiff materials, and in cells embedded in 3D soft hydrogel. ARHGEF9 is required for melanoma cells to invade 3D matrices. Depletion of ARHGEF9 results in loss of tension at focal adhesions decreased cell-wide contractility, and the inability to stabilize protrusions. Taken together we show that ARHGEF9 promotes the formation of actin-rich filopodia, which serves to establish and stabilize adhesions and determine melanoma cell shape.
Collapse
Affiliation(s)
- Vicky Bousgouni
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Oliver Inge
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
- Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - David Robertson
- Division of Breast Cancer Research, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Ian Jones
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| | - Innes Clatworthy
- Core Research Laboratories, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Chris Bakal
- Division of Cancer Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
| |
Collapse
|
21
|
Enhanced incorporation of subnanometer tags into cellular proteins for fluorescence nanoscopy via optimized genetic code expansion. Proc Natl Acad Sci U S A 2022; 119:e2201861119. [PMID: 35858298 PMCID: PMC9304028 DOI: 10.1073/pnas.2201861119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
With few-nanometer resolution recently achieved by a new generation of fluorescence nanoscopes (MINFLUX and MINSTED), the size of the tags used to label proteins will increasingly limit the ability to dissect nanoscopic biological structures. Bioorthogonal (click) chemical groups are powerful tools for the specific detection of biomolecules. Through the introduction of an engineered aminoacyl–tRNA synthetase/tRNA pair (tRNA: transfer ribonucleic acid), genetic code expansion allows for the site-specific introduction of amino acids with “clickable” side chains into proteins of interest. Well-defined label positions and the subnanometer scale of the protein modification provide unique advantages over other labeling approaches for imaging at molecular-scale resolution. We report that, by pairing a new N-terminally optimized pyrrolysyl–tRNA synthetase (chPylRS
2020
) with a previously engineered orthogonal tRNA, clickable amino acids are incorporated with improved efficiency into bacteria and into mammalian cells. The resulting enhanced genetic code expansion machinery was used to label β-actin in U2OS cell filopodia for MINFLUX imaging with minimal separation of fluorophores from the protein backbone. Selected data were found to be consistent with previously reported high-resolution information from cryoelectron tomography about the cross-sectional filament bundling architecture. Our study underscores the need for further improvements to the degree of labeling with minimal-offset methods in order to fully exploit molecular-scale optical three-dimensional resolution.
Collapse
|
22
|
Chang M, Lee OC, Bu G, Oh J, Yunn NO, Ryu SH, Kwon HB, Kolomeisky AB, Shim SH, Doh J, Jeon JH, Lee JB. Formation of cellular close-ended tunneling nanotubes through mechanical deformation. SCIENCE ADVANCES 2022; 8:eabj3995. [PMID: 35353579 PMCID: PMC8967236 DOI: 10.1126/sciadv.abj3995] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Membrane nanotubes or tunneling nanotubes (TNTs) that connect cells have been recognized as a previously unidentified pathway for intercellular transport between distant cells. However, it is unknown how this delicate structure, which extends over tens of micrometers and remains robust for hours, is formed. Here, we found that a TNT develops from a double filopodial bridge (DFB) created by the physical contact of two filopodia through helical deformation of the DFB. The transition of a DFB to a close-ended TNT is most likely triggered by disruption of the adhesion of two filopodia by mechanical energy accumulated in a twisted DFB when one of the DFB ends is firmly attached through intercellular cadherin-cadherin interactions. These studies pinpoint the mechanistic questions about TNTs and elucidate a formation mechanism.
Collapse
Affiliation(s)
- Minhyeok Chang
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - O-chul Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Gayun Bu
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Jaeho Oh
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Na-Oh Yunn
- POSTECH Biotech Center, Pohang 37673, Korea
| | - Sung Ho Ryu
- Department of Life Sciences, POSTECH, Pohang 37673, Korea
| | - Hyung-Bae Kwon
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Sang-Hee Shim
- Department of Chemistry, Korea University, Seoul 02481, Korea
| | - Junsang Doh
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea
| | - Jae-Hyung Jeon
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- Asia Pacific Center for Theoretical Physics (APCTP), Pohang 37673, Korea
- Corresponding author. (J.-B.L.); (J.-H.J.)
| | - Jong-Bong Lee
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
- Asia Pacific Center for Theoretical Physics (APCTP), Pohang 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang 37673, Korea
- Corresponding author. (J.-B.L.); (J.-H.J.)
| |
Collapse
|