1
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Doha U, Aydin O, Joy MSH, Emon B, Drennan W, Saif MTA. Disorder to order transition in cell-ECM systems mediated by cell-cell collective interactions. Acta Biomater 2022; 154:290-301. [PMID: 36243372 DOI: 10.1016/j.actbio.2022.10.012] [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: 03/19/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 12/14/2022]
Abstract
Cells in functional tissues execute various collective activities to achieve diverse ordered processes including wound healing, organogenesis, and tumor formation. How a group of individually operating cells initiate such complex collective processes is still not clear. Here, we report that cells in 3D extracellular matrix (ECM) initiate collective behavior by forming cell-ECM network when the cells are within a critical distance from each other. We employed compaction of free-floating (FF) 3D collagen gels with embedded fibroblasts as a model system to study collective behavior and found a sharp transition in the amount of compaction as a function of cell-cell distance, reminiscent of phase transition in materials. Within the critical distance, cells remodel the ECM irreversibly, and form dense collagen bridges between each other resulting in the formation of a network. Beyond the critical distance, cells exhibit Brownian dynamics and only deform the matrix reversibly in a transient manner with no memory of history, thus maintaining the disorder. Network formation seems to be a necessary and sufficient condition to trigger collective behavior and a disorder-to order transition. STATEMENT OF SIGNIFICANCE: Macroscopic compaction of in vitro collagen gels is mediated by collective mechanical interaction of cells. Previous studies on cell-induced ECM compaction suggest the existence of a critical cell density and phase transition associated with this phenomenon. Cell-mediated mechanical remodeling and global compaction of ECM has mostly been studied at steady state. Our study reveals a link between a transition in cell dynamics and material microstructure as cells collectively compact collagen gels. It underscores the significance of temporal evolution of these cell-ECM systems in understanding the mechanism of such collective action and provides insights on the process from a mechanistic viewpoint. These insights can be valuable in understanding dynamic pathological processes such as, cancer progression and wound healing, as well as engineering biomaterials and regenerative tissue mimics.
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Affiliation(s)
- Umnia Doha
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States
| | - Onur Aydin
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States
| | - Md Saddam Hossain Joy
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States
| | - Bashar Emon
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States
| | - William Drennan
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States
| | - M Taher A Saif
- Department of Mechanical Science and Engineering, University of Illinois Urbana Champaign, United States.
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2
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Mytiliniou M, Wondergem JAJ, Schmidt T, Heinrich D. Impact of neurite alignment on organelle motion. J R Soc Interface 2022; 19:20210617. [PMID: 35135294 PMCID: PMC8825987 DOI: 10.1098/rsif.2021.0617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Intracellular transport is pivotal for cell growth and survival. Malfunctions in this process have been associated with devastating neurodegenerative diseases, highlighting the need for a deeper understanding of the mechanisms involved. Here, we use an experimental methodology that leads neurites of differentiated PC12 cells into either one of two configurations: a one-dimensional configuration, where the neurites align along lines, or a two-dimensional configuration, where the neurites adopt a random orientation and shape on a flat substrate. We subsequently monitored the motion of functional organelles, the lysosomes, inside the neurites. Implementing a time-resolved analysis of the mean-squared displacement, we quantitatively characterized distinct motion modes of the lysosomes. Our results indicate that neurite alignment gives rise to faster diffusive and super-diffusive lysosomal motion than the situation in which the neurites are randomly oriented. After inducing lysosome swelling through an osmotic challenge by sucrose, we confirmed the predicted slowdown in diffusive mobility. Surprisingly, we found that the swelling-induced mobility change affected each of the (sub-/super-)diffusive motion modes differently and depended on the alignment configuration of the neurites. Our findings imply that intracellular transport is significantly and robustly dependent on cell morphology, which might in part be controlled by the extracellular matrix.
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Affiliation(s)
- Maria Mytiliniou
- Leiden Institute of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2333 CA Leiden, The Netherlands
| | - Joeri A J Wondergem
- Leiden Institute of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2333 CA Leiden, The Netherlands
| | - Thomas Schmidt
- Leiden Institute of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2333 CA Leiden, The Netherlands
| | - Doris Heinrich
- Leiden Institute of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2333 CA Leiden, The Netherlands.,Institute for Bioprocessing and Analytical Measurement Techniques, Rosenhof, 37308 Heilbad Heiligenstadt, Germany.,Faculty for Mathematics and Natural Sciences, Technische Universität Ilmenau, 98693 Ilmenau, Germany.,Fraunhofer Institute for Silicate Research ISC, 97082 Würzburg, Germany
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3
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Large-Scale, Wavelet-Based Analysis of Lysosomal Trajectories and Co-Movements of Lysosomes with Nanoparticle Cargos. Cells 2022; 11:cells11020270. [PMID: 35053385 PMCID: PMC8774281 DOI: 10.3390/cells11020270] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 02/01/2023] Open
Abstract
Lysosomes—that is, acidic organelles known for degradation/recycling—move through the cytoplasm alternating between bursts of active transport and short, diffusive motions or even pauses. While their mobility is essential for lysosomes’ fusogenic and non-fusogenic interactions with target organelles, their movements have not been characterized in adequate detail. Here, large-scale statistical analysis of lysosomal movement trajectories reveals that lysosome trajectories in all examined cell types—both cancer and noncancerous ones—are superdiffusive and characterized by heavy-tailed distributions of run and flight lengths. Consideration of Akaike weights for various potential models (lognormal, power law, truncated power law, stretched exponential, and exponential) indicates that the experimental data are best described by the lognormal distribution, which, in turn, can be related to one of the space-search strategies particularly effective when “thorough” search needs to balance search for rare target(s) (organelles). In addition, automated, wavelet-based analysis allows for co-tracking the motions of lysosomes and the cargos they carry—particularly the nanoparticle aggregates known to cause selective lysosome disruption in cancerous cells. The methods we describe here could help study nanoparticle assemblies, viruses, and other objects transported inside various vesicle types, as well as coordinated movements of organelles/particles in the cytoplasm. Custom-written code that includes integrated workflow for our analyses is made available for academic use.
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4
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Zepeda O J, Bishop LDC, Dutta C, Sarkar-Banerjee S, Leung WW, Landes CF. Untying the Gordian KNOT: Unbiased Single Particle Tracking Using Point Clouds and Adaptive Motion Analysis. J Phys Chem A 2021; 125:8723-8733. [PMID: 34559965 DOI: 10.1021/acs.jpca.1c06100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Achieving mechanistic understanding of transport in complex environments such as inside cells or at polymer interfaces is challenging. We need better ways to image transport in 3-D and better single particle tracking algorithms to determine transport that are not systemically biased toward any classical motion model. Here we present an unbiased single particle tracking algorithm: Knowing Nothing Outside Tracking (KNOT). KNOT uses point clouds provided by iterative deconvolution to educate individual particle localizations and link particle positions between frames to achieve 2-D and 3-D tracking. Information from prior point clouds fuels an independent adaptive motion model for each particle to avoid global models that could introduce biases. KNOT competes with or surpasses other 2-D methods from the 2012 particle tracking challenge while accurately tracking adsorption dynamics of proteins on polymer surfaces and early endosome transport in live cells in 3-D. We apply KNOT to study 3-D endosome transport to reveal new physical insight into locally directed and diffusive transport in live cells. Our analysis demonstrates better accuracy in classifying local motion and its direction compared to previous methods, revealing intricate intracellular transport heterogeneities.
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Affiliation(s)
- Jorge Zepeda O
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
| | - Logan D C Bishop
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Chayan Dutta
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | | | - Wesley W Leung
- Applied Physics Graduate Program, Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States.,Department of Chemistry, Rice University, Houston, Texas 77005, United States.,Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
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5
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Manipulation of Axonal Outgrowth via Exogenous Low Forces. Int J Mol Sci 2020; 21:ijms21218009. [PMID: 33126477 PMCID: PMC7663625 DOI: 10.3390/ijms21218009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/24/2022] Open
Abstract
Neurons are mechanosensitive cells. The role of mechanical force in the process of neurite initiation, elongation and sprouting; nerve fasciculation; and neuron maturation continues to attract considerable interest among scientists. Force is an endogenous signal that stimulates all these processes in vivo. The axon is able to sense force, generate force and, ultimately, transduce the force in a signal for growth. This opens up fascinating scenarios. How are forces generated and sensed in vivo? Which molecular mechanisms are responsible for this mechanotransduction signal? Can we exploit exogenously applied forces to mimic and control this process? How can these extremely low forces be generated in vivo in a non-invasive manner? Can these methodologies for force generation be used in regenerative therapies? This review addresses these questions, providing a general overview of current knowledge on the applications of exogenous forces to manipulate axonal outgrowth, with a special focus on forces whose magnitude is similar to those generated in vivo. We also review the principal methodologies for applying these forces, providing new inspiration and insights into the potential of this approach for future regenerative therapies.
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6
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Sabharwal V, Koushika SP. Crowd Control: Effects of Physical Crowding on Cargo Movement in Healthy and Diseased Neurons. Front Cell Neurosci 2019; 13:470. [PMID: 31708745 PMCID: PMC6823667 DOI: 10.3389/fncel.2019.00470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 10/02/2019] [Indexed: 01/22/2023] Open
Abstract
High concentration of cytoskeletal filaments, organelles, and proteins along with the space constraints due to the axon's narrow geometry lead inevitably to intracellular physical crowding along the axon of a neuron. Local cargo movement is essential for maintaining steady cargo transport in the axon, and this may be impeded by physical crowding. Molecular motors that mediate active transport share movement mechanisms that allow them to bypass physical crowding present on microtubule tracks. Many neurodegenerative diseases, irrespective of how they are initiated, show increased physical crowding owing to the greater number of stalled organelles and structural changes associated with the cytoskeleton. Increased physical crowding may be a significant factor in slowing cargo transport to synapses, contributing to disease progression and culminating in the dying back of the neuronal process. This review explores the idea that physical crowding can impede cargo movement along the neuronal process. We examine the sources of physical crowding and strategies used by molecular motors that might enable cargo to circumvent physically crowded locations. Finally, we describe sub-cellular changes in neurodegenerative diseases that may alter physical crowding and discuss the implications of such changes on cargo movement.
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Affiliation(s)
| | - Sandhya P. Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India
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7
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Closer to Nature Through Dynamic Culture Systems. Cells 2019; 8:cells8090942. [PMID: 31438519 PMCID: PMC6769584 DOI: 10.3390/cells8090942] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 12/12/2022] Open
Abstract
Mechanics in the human body are required for normal cell function at a molecular level. It is now clear that mechanical stimulations play significant roles in cell growth, differentiation, and migration in normal and diseased cells. Recent studies have led to the discovery that normal and cancer cells have different mechanosensing properties. Here, we discuss the application and the physiological and pathological meaning of mechanical stimulations. To reveal the optimal conditions for mimicking an in vivo microenvironment, we must, therefore, discern the mechanotransduction occurring in cells.
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8
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Posey D, Blaisdell-Pijuan P, Knoll SK, Saif TA, Ahmed WW. Small-scale displacement fluctuations of vesicles in fibroblasts. Sci Rep 2018; 8:13294. [PMID: 30185883 PMCID: PMC6125338 DOI: 10.1038/s41598-018-31656-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 08/16/2018] [Indexed: 11/09/2022] Open
Abstract
The intracellular environment is a dynamic space filled with various organelles moving in all directions. Included in this diverse group of organelles are vesicles, which are involved in transport of molecular cargo throughout the cell. Vesicles move in either a directed or non-directed fashion, often depending on interactions with cytoskeletal proteins such as microtubules, actin filaments, and molecular motors. How these proteins affect the local fluctuations of vesicles in the cytoplasm is not clear since they have the potential to both facilitate and impede movement. Here we show that vesicle mobility is significantly affected by myosin-II, even though it is not a cargo transport motor. We find that myosin-II activity increases the effective diffusivity of vesicles and its inhibition facilitates longer states of non-directed motion. Our study suggests that altering myosin-II activity in the cytoplasm of cells can modulate the mobility of vesicles, providing a possible mechanism for cells to dynamically tune the cytoplasmic environment in space and time.
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Affiliation(s)
- Danielle Posey
- Department of Biological Science, California State University, Fullerton, CA, USA
| | | | - Samantha K Knoll
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL, USA
| | - Taher A Saif
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL, USA
| | - Wylie W Ahmed
- Department of Physics, California State University, Fullerton, CA, USA.
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9
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Gahl TJ, Kunze A. Force-Mediating Magnetic Nanoparticles to Engineer Neuronal Cell Function. Front Neurosci 2018; 12:299. [PMID: 29867315 PMCID: PMC5962660 DOI: 10.3389/fnins.2018.00299] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
Abstract
Cellular processes like membrane deformation, cell migration, and transport of organelles are sensitive to mechanical forces. Technically, these cellular processes can be manipulated through operating forces at a spatial precision in the range of nanometers up to a few micrometers through chaperoning force-mediating nanoparticles in electrical, magnetic, or optical field gradients. But which force-mediating tool is more suitable to manipulate cell migration, and which, to manipulate cell signaling? We review here the differences in forces sensation to control and engineer cellular processes inside and outside the cell, with a special focus on neuronal cells. In addition, we discuss technical details and limitations of different force-mediating approaches and highlight recent advancements of nanomagnetics in cell organization, communication, signaling, and intracellular trafficking. Finally, we give suggestions about how force-mediating nanoparticles can be used to our advantage in next-generation neurotherapeutic devices.
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Affiliation(s)
| | - Anja Kunze
- Department of Electrical and Computer Engineering, Montana State University, Bozeman, MT, United States
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10
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Makhija E, Jagielska A, Zhu L, Bost AC, Ong W, Chew SY, Shivashankar GV, Van Vliet KJ. Mechanical Strain Alters Cellular and Nuclear Dynamics at Early Stages of Oligodendrocyte Differentiation. Front Cell Neurosci 2018; 12:59. [PMID: 29559894 PMCID: PMC5845683 DOI: 10.3389/fncel.2018.00059] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/19/2018] [Indexed: 11/13/2022] Open
Abstract
Mechanical and physical stimuli including material stiffness and topography or applied mechanical strain have been demonstrated to modulate differentiation of glial progenitor and neural stem cells. Recent studies probing such mechanotransduction in oligodendrocytes have focused chiefly on the biomolecular components. However, the cell-level biophysical changes associated with such responses remain largely unknown. Here, we explored mechanotransduction in oligodendrocyte progenitor cells (OPCs) during the first 48 h of differentiation induction by quantifying the biophysical state in terms of nuclear dynamics, cytoskeleton organization, and cell migration. We compared these mechanophenotypic changes in OPCs exposed to both chemical cues (differentiation factors) and mechanical cues (static tensile strain of 10%) with those exposed to only those chemical cues. We observed that mechanical strain significantly hastened the dampening of nuclear fluctuations and decreased OPC migration, consistent with the progression of differentiation. Those biophysical changes were accompanied by increased production of the intracellular microtubule network. These observations provide insights into mechanisms by which mechanical strain of physiological magnitude could promote differentiation of progenitor cells to oligodendrocytes via inducing intracellular biophysical responses over hours to days post induction.
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Affiliation(s)
- Ekta Makhija
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore
| | - Anna Jagielska
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Lena Zhu
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Alexander C Bost
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - William Ong
- NTU Institute for Health Technologies (Health Tech NTU), Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
| | - Sing Y Chew
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - G V Shivashankar
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore.,Mechanobiology Institute, Singapore, Singapore.,The FIRC Institute of Molecular Oncology, Milan, Italy
| | - Krystyn J Van Vliet
- BioSystems and Micromechanics Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, CREATE, Singapore, Singapore.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
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11
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Liu YL, Perillo EP, Liu C, Yu P, Chou CK, Hung MC, Dunn AK, Yeh HC. Segmentation of 3D Trajectories Acquired by TSUNAMI Microscope: An Application to EGFR Trafficking. Biophys J 2017; 111:2214-2227. [PMID: 27851944 DOI: 10.1016/j.bpj.2016.09.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 11/30/2022] Open
Abstract
Whereas important discoveries made by single-particle tracking have changed our view of the plasma membrane organization and motor protein dynamics in the past three decades, experimental studies of intracellular processes using single-particle tracking are rather scarce because of the lack of three-dimensional (3D) tracking capacity. In this study we use a newly developed 3D single-particle tracking method termed TSUNAMI (Tracking of Single particles Using Nonlinear And Multiplexed Illumination) to investigate epidermal growth factor receptor (EGFR) trafficking dynamics in live cells at 16/43 nm (xy/z) spatial resolution, with track duration ranging from 2 to 10 min and vertical tracking depth up to tens of microns. To analyze the long 3D trajectories generated by the TSUNAMI microscope, we developed a trajectory analysis algorithm, which reaches 81% segment classification accuracy in control experiments (termed simulated movement experiments). When analyzing 95 EGF-stimulated EGFR trajectories acquired in live skin cancer cells, we find that these trajectories can be separated into three groups-immobilization (24.2%), membrane diffusion only (51.6%), and transport from membrane to cytoplasm (24.2%). When EGFRs are membrane-bound, they show an interchange of Brownian diffusion and confined diffusion. When EGFRs are internalized, transitions from confined diffusion to directed diffusion and from directed diffusion back to confined diffusion are clearly seen. This observation agrees well with the model of clathrin-mediated endocytosis.
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Affiliation(s)
- Yen-Liang Liu
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas
| | - Evan P Perillo
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas
| | - Cong Liu
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas
| | - Peter Yu
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas
| | - Chao-Kai Chou
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas; Center for Molecular Medicine and Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
| | - Mien-Chie Hung
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas; Center for Molecular Medicine and Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan
| | - Andrew K Dunn
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas.
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12
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Jagielska A, Lowe AL, Makhija E, Wroblewska L, Guck J, Franklin RJM, Shivashankar GV, Van Vliet KJ. Mechanical Strain Promotes Oligodendrocyte Differentiation by Global Changes of Gene Expression. Front Cell Neurosci 2017; 11:93. [PMID: 28473753 PMCID: PMC5397481 DOI: 10.3389/fncel.2017.00093] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/20/2017] [Indexed: 11/13/2022] Open
Abstract
Differentiation of oligodendrocyte progenitor cells (OPC) to oligodendrocytes and subsequent axon myelination are critical steps in vertebrate central nervous system (CNS) development and regeneration. Growing evidence supports the significance of mechanical factors in oligodendrocyte biology. Here, we explore the effect of mechanical strains within physiological range on OPC proliferation and differentiation, and strain-associated changes in chromatin structure, epigenetics, and gene expression. Sustained tensile strain of 10-15% inhibited OPC proliferation and promoted differentiation into oligodendrocytes. This response to strain required specific interactions of OPCs with extracellular matrix ligands. Applied strain induced changes in nuclear shape, chromatin organization, and resulted in enhanced histone deacetylation, consistent with increased oligodendrocyte differentiation. This response was concurrent with increased mRNA levels of the epigenetic modifier histone deacetylase Hdac11. Inhibition of HDAC proteins eliminated the strain-mediated increase of OPC differentiation, demonstrating a role of HDACs in mechanotransduction of strain to chromatin. RNA sequencing revealed global changes in gene expression associated with strain. Specifically, expression of multiple genes associated with oligodendrocyte differentiation and axon-oligodendrocyte interactions was increased, including cell surface ligands (Ncam, ephrins), cyto- and nucleo-skeleton genes (Fyn, actinins, myosin, nesprin, Sun1), transcription factors (Sox10, Zfp191, Nkx2.2), and myelin genes (Cnp, Plp, Mag). These findings show how mechanical strain can be transmitted to the nucleus to promote oligodendrocyte differentiation, and identify the global landscape of signaling pathways involved in mechanotransduction. These data provide a source of potential new therapeutic avenues to enhance OPC differentiation in vivo.
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Affiliation(s)
- Anna Jagielska
- Department of Materials Science and Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA
| | - Alexis L Lowe
- Department of Neuroscience, Wellesley CollegeWellesley, MA, USA
| | - Ekta Makhija
- Mechanobiology Institute, National University of SingaporeSingapore, Singapore
| | - Liliana Wroblewska
- Department of Biological Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA
| | - Jochen Guck
- Biotechnology Center, Technische Universität DresdenDresden, Germany
| | - Robin J M Franklin
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, University of CambridgeCambridge, UK
| | - G V Shivashankar
- Mechanobiology Institute, National University of SingaporeSingapore, Singapore
| | - Krystyn J Van Vliet
- Department of Materials Science and Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA.,Department of Biological Engineering, Massachusetts Institute of TechnologyCambridge, MA, USA.,BioSystems and Micromechanics Inter-Disciplinary Research Group, Singapore-MIT Alliance for Research and TechnologySingapore, Singapore
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13
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Kunze A, Murray CT, Godzich C, Lin J, Owsley K, Tay A, Di Carlo D. Modulating motility of intracellular vesicles in cortical neurons with nanomagnetic forces on-chip. LAB ON A CHIP 2017; 17:842-854. [PMID: 28164203 PMCID: PMC5400667 DOI: 10.1039/c6lc01349j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Vesicle transport is a major underlying mechanism of cell communication. Inhibiting vesicle transport in brain cells results in blockage of neuronal signals, even in intact neuronal networks. Modulating intracellular vesicle transport can have a huge impact on the development of new neurotherapeutic concepts, but only if we can specifically interfere with intracellular transport patterns. Here, we propose to modulate motion of intracellular lipid vesicles in rat cortical neurons based on exogenously bioconjugated and cell internalized superparamagnetic iron oxide nanoparticles (SPIONs) within microengineered magnetic gradients on-chip. Upon application of 6-126 pN on intracellular vesicles in neuronal cells, we explored how the magnetic force stimulus impacts the motion pattern of vesicles at various intracellular locations without modulating the entire cell morphology. Altering vesicle dynamics was quantified using, mean square displacement, a caging diameter and the total traveled distance. We observed a de-acceleration of intercellular vesicle motility, while applying nanomagnetic forces to cultured neurons with SPIONs, which can be explained by a decrease in motility due to opposing magnetic force direction. Ultimately, using nanomagnetic forces inside neurons may permit us to stop the mis-sorting of intracellular organelles, proteins and cell signals, which have been associated with cellular dysfunction. Furthermore, nanomagnetic force applications will allow us to wirelessly guide axons and dendrites by exogenously using permanent magnetic field gradients.
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Affiliation(s)
- Anja Kunze
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA. and Department of Electrical and Computer Engineering, Montana State University, Bozeman, Montana 59717, USA.
| | - Coleman Tylor Murray
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
| | - Chanya Godzich
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
| | - Jonathan Lin
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
| | - Keegan Owsley
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
| | - Andy Tay
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA.
| | - Dino Di Carlo
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA. and California NanoSystems Institute, University of California, Los Angeles, California 90095, USA and Jonsson Comprehensive Cancer Research Center, University of California, Los Angeles, California 90095, USA
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14
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Moreira HT, Silva IM, Sousa M, Sampaio P, Silva Cunha JP. Neurotransmitter vesicle movement dynamics in living neurons. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:6265-8. [PMID: 26737724 DOI: 10.1109/embc.2015.7319824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The communication between two neurons is established by endogenous chemical particles aggregated in vesicles that move along the axons. It is known that an abnormal transport of these vesicles is correlated with neurodegenerative diseases. The quantification of the dynamics of vesicles movement can therefore be a window to study early detection of such diseases. Nevertheless, most of the studies in the literature rely on manual tracking techniques. In this paper we present a novel methodology for quantifying neurotransmitter vesicle dynamics by using a combination of image tracking and classification algorithms. We use confocal microscopy videos of living neurons to detect and classify vesicles using support vector machine (SVM), while motion is extracted via global nearest neighbor (GNN) tracking approach. Results of the classification algorithm are presented and compared to a ground truth dataset defined by experts. Sensitivity of 90% and specificity of 97% were obtained at a much lower computational cost than an established method from the literature (0.24s/frame vs. 125s/frame). These preliminary results suggest the great potential of the method and tool we have been developing for single particle movement dynamics measure in living cells.
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Combs-Bachmann RE, Johnson JN, Vytla D, Hussey AM, Kilfoil ML, Chambers JJ. Ligand-directed delivery of fluorophores to track native calcium-permeable AMPA receptors in neuronal cultures. J Neurochem 2015; 133:320-9. [PMID: 25640258 DOI: 10.1111/jnc.13051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 01/15/2015] [Accepted: 01/21/2015] [Indexed: 12/01/2022]
Abstract
Subcellular trafficking of neuronal receptors is known to play a key role in synaptic development, homeostasis, and plasticity. We have developed a ligand-targeted and photo-cleavable probe for delivering a synthetic fluorophore to AMPA receptors natively expressed in neurons. After a receptor is bound to the ligand portion of the probe molecule, a proteinaceous nucleophile reacts with an electrophile on the probe, covalently bonding the two species. The ligand may then be removed by photolysis, returning the receptor to its non-liganded state while leaving intact the new covalent bond between the receptor and the fluorophore. This strategy was used to label polyamine-sensitive receptors, including calcium-permeable AMPA receptors, in live hippocampal neurons from rats. Here, we describe experiments where we examined specificity, competition, and concentration on labeling efficacy as well as quantified receptor trafficking. Pharmacological competition during the labeling step with either a competitive or non-competitive glutamate receptor antagonist prevented the majority of labeling observed without a blocker. In other experiments, labeled receptors were observed to alter their locations and we were able to track and quantify their movements. We used a small molecule, ligand-directed probe to deliver synthetic fluorophores to endogenously expressed glutamate receptors for the purpose of tracking these receptors on live, hippocampal neurons. We found that clusters of receptors appear to move at similar rates to previous studies. We also found that the polyamine toxin pharmacophore likely binds to receptors in addition to calcium-permeable AMPA receptors.
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Ahmed WW, Saif TA. Active transport of vesicles in neurons is modulated by mechanical tension. Sci Rep 2014; 4:4481. [PMID: 24670781 PMCID: PMC3967286 DOI: 10.1038/srep04481] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 02/24/2014] [Indexed: 11/19/2022] Open
Abstract
Effective intracellular transport of proteins and organelles is critical in cells, and is especially important for ensuring proper neuron functionality. In neurons, most proteins are synthesized in the cell body and must be transported through thin structures over long distances where normal diffusion is insufficient. Neurons transport subcellular cargo along axons and neurites through a stochastic interplay of active and passive transport. Mechanical tension is critical in maintaining proper function in neurons, but its role in transport is not well understood. To this end, we investigate the active and passive transport of vesicles in Aplysia neurons while changing neurite tension via applied strain, and quantify the resulting dynamics. We found that tension in neurons modulates active transport of vesicles by increasing the probability of active motion, effective diffusivity, and induces a retrograde bias. We show that mechanical tension modulates active transport processes in neurons and that external forces can couple to internal (subcellular) forces and change the overall transport dynamics.
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Affiliation(s)
- Wylie W Ahmed
- 1] Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL 61801 [2]
| | - Taher A Saif
- Department of Mechanical Science and Engineering, University of Illinois, Urbana, IL 61801
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