1
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Sarkar T, Krajnc M. Graph topological transformations in space-filling cell aggregates. PLoS Comput Biol 2024; 20:e1012089. [PMID: 38743660 PMCID: PMC11093388 DOI: 10.1371/journal.pcbi.1012089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Cell rearrangements are fundamental mechanisms driving large-scale deformations of living tissues. In three-dimensional (3D) space-filling cell aggregates, cells rearrange through local topological transitions of the network of cell-cell interfaces, which is most conveniently described by the vertex model. Since these transitions are not yet mathematically properly formulated, the 3D vertex model is generally difficult to implement. The few existing implementations rely on highly customized and complex software-engineering solutions, which cannot be transparently delineated and are thus mostly non-reproducible. To solve this outstanding problem, we propose a reformulation of the vertex model. Our approach, called Graph Vertex Model (GVM), is based on storing the topology of the cell network into a knowledge graph with a particular data structure that allows performing cell-rearrangement events by simple graph transformations. Importantly, when these same transformations are applied to a two-dimensional (2D) polygonal cell aggregate, they reduce to a well-known T1 transition, thereby generalizing cell-rearrangements in 2D and 3D space-filling packings. This result suggests that the GVM's graph data structure may be the most natural representation of cell aggregates and tissues. We also develop a Python package that implements GVM, relying on a graph-database-management framework Neo4j. We use this package to characterize an order-disorder transition in 3D cell aggregates, driven by active noise and we find aggregates undergoing efficient ordering close to the transition point. In all, our work showcases knowledge graphs as particularly suitable data models for structured storage, analysis, and manipulation of tissue data.
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Affiliation(s)
- Tanmoy Sarkar
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Matej Krajnc
- Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana, Slovenia
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2
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Bozdag GO, Zamani-Dahaj SA, Day TC, Kahn PC, Burnetti AJ, Lac DT, Tong K, Conlin PL, Balwani AH, Dyer EL, Yunker PJ, Ratcliff WC. De novo evolution of macroscopic multicellularity. Nature 2023; 617:747-754. [PMID: 37165189 PMCID: PMC10425966 DOI: 10.1038/s41586-023-06052-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 04/05/2023] [Indexed: 05/12/2023]
Abstract
While early multicellular lineages necessarily started out as relatively simple groups of cells, little is known about how they became Darwinian entities capable of sustained multicellular evolution1-3. Here we investigate this with a multicellularity long-term evolution experiment, selecting for larger group size in the snowflake yeast (Saccharomyces cerevisiae) model system. Given the historical importance of oxygen limitation4, our ongoing experiment consists of three metabolic treatments5-anaerobic, obligately aerobic and mixotrophic yeast. After 600 rounds of selection, snowflake yeast in the anaerobic treatment group evolved to be macroscopic, becoming around 2 × 104 times larger (approximately mm scale) and about 104-fold more biophysically tough, while retaining a clonal multicellular life cycle. This occurred through biophysical adaptation-evolution of increasingly elongate cells that initially reduced the strain of cellular packing and then facilitated branch entanglements that enabled groups of cells to stay together even after many cellular bonds fracture. By contrast, snowflake yeast competing for low oxygen5 remained microscopic, evolving to be only around sixfold larger, underscoring the critical role of oxygen levels in the evolution of multicellular size. Together, this research provides unique insights into an ongoing evolutionary transition in individuality, showing how simple groups of cells overcome fundamental biophysical limitations through gradual, yet sustained, multicellular evolution.
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Affiliation(s)
- G Ozan Bozdag
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
| | - Seyed Alireza Zamani-Dahaj
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Thomas C Day
- School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Penelope C Kahn
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anthony J Burnetti
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Dung T Lac
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kai Tong
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter L Conlin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Aishwarya H Balwani
- School of Electrical & Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Eva L Dyer
- School of Electrical & Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Peter J Yunker
- Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, GA, USA.
| | - William C Ratcliff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
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3
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Mukherjee M, Levine H. Cluster size distribution of cells disseminating from a primary tumor. PLoS Comput Biol 2021; 17:e1009011. [PMID: 34758019 PMCID: PMC8608333 DOI: 10.1371/journal.pcbi.1009011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 11/22/2021] [Accepted: 10/25/2021] [Indexed: 01/06/2023] Open
Abstract
The first stage of the metastatic cascade often involves motile cells emerging from a primary tumor either as single cells or as clusters. These cells enter the circulation, transit to other parts of the body and finally are responsible for growth of secondary tumors in distant organs. The mode of dissemination is believed to depend on the EMT nature (epithelial, hybrid or mesenchymal) of the cells. Here, we calculate the cluster size distribution of these migrating cells, using a mechanistic computational model, in presence of different degree of EMT-ness of the cells; EMT is treated as given rise to changes in their active motile forces (μ) and cell-medium surface tension (Γ). We find that, for (μ > μmin, Γ > 1), when the cells are hybrid in nature, the mean cluster size, N¯∼Γ2.0/μ2.8, where μmin increases with increase in Γ. For Γ ≤ 0, N¯=1, the cells behave as completely mesenchymal. In presence of spectrum of hybrid states with different degree of EMT-ness (motility) in primary tumor, the cells which are relatively more mesenchymal (higher μ) in nature, form larger clusters, whereas the smaller clusters are relatively more epithelial (lower μ). Moreover, the heterogeneity in μ is comparatively higher for smaller clusters with respect to that for larger clusters. We also observe that more extended cell shapes promote the formation of smaller clusters. Overall, this study establishes a framework which connects the nature and size of migrating clusters disseminating from a primary tumor with the phenotypic composition of the tumor, and can lead to the better understanding of metastasis. In the process of metastasis, tumor cells disseminate from the primary tumor either as single cells or multicellular clusters. These clusters are potential contributor to the initiation of secondary tumor in distant organs. Our computational model captures the size distribution of migrating clusters depending on the adhesion and motility of the cells (which determine the degree of their EMT nature). Furthermore, we investigate the effect of heterogeneity of cell types in the primary tumor on the resultant heterogeneity of cell types in clusters of different sizes. We believe that the understanding the formation and nature of these clusters, dangerous actors in the deadly aspect of cancer progression, will be useful for improving prognostic methods and eventually better treatments.
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Affiliation(s)
- Mrinmoy Mukherjee
- Center for Theoretical Biological Physics, Northeastern University, Boston, Massachusetts, United States of America
- * E-mail:
| | - Herbert Levine
- Center for Theoretical Biological Physics, Northeastern University, Boston, Massachusetts, United States of America
- Depts. of Physics and Bioengineering, Northeastern University, Boston, Massachusetts, United States of America
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4
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Guo Y, Nitzan M, Brenner MP. Programming cell growth into different cluster shapes using diffusible signals. PLoS Comput Biol 2021; 17:e1009576. [PMID: 34748539 PMCID: PMC8601629 DOI: 10.1371/journal.pcbi.1009576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 11/18/2021] [Accepted: 10/19/2021] [Indexed: 11/18/2022] Open
Abstract
Advances in genetic engineering technologies have allowed the construction of artificial genetic circuits, which have been used to generate spatial patterns of differential gene expression. However, the question of how cells can be programmed, and how complex the rules need to be, to achieve a desired tissue morphology has received less attention. Here, we address these questions by developing a mathematical model to study how cells can collectively grow into clusters with different structural morphologies by secreting diffusible signals that can influence cellular growth rates. We formulate how growth regulators can be used to control the formation of cellular protrusions and how the range of achievable structures scales with the number of distinct signals. We show that a single growth inhibitor is insufficient for the formation of multiple protrusions but may be achieved with multiple growth inhibitors, and that other types of signals can regulate the shape of protrusion tips. These examples illustrate how our approach could potentially be used to guide the design of regulatory circuits for achieving a desired target structure.
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Affiliation(s)
- Yipei Guo
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
- Program in Biophysics, Harvard University, Boston, Massachusetts, United States of America
- * E-mail:
| | - Mor Nitzan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
| | - Michael P. Brenner
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, United States of America
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5
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Dobrodeeva LK, Samodova AV, Balashova SN, Pashinskaya KO. Intercellular Interactions in Peripheral Venous Blood in Practically Healthy Residents of High Latitudes. Biomed Res Int 2021; 2021:7086108. [PMID: 34513996 PMCID: PMC8433011 DOI: 10.1155/2021/7086108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/17/2021] [Indexed: 12/05/2022]
Abstract
The paper presents the results of studying the immunological parameters of 369 people who were practically healthy at the time of the survey, 298 women and 71 men, of which 216 people are living in the European North of the Russian Federation (173 women and 43 men) and 153 are residents of the Arctic (125 women and 28 men). The study was carried out in the morning (08:00-10:00 am). The study included the determination of the aggregation of erythrocytes, platelets, neutrophilic granulocytes, lymphocytes, hemogram study, hematological analysis, enzyme immunoassay, and flow cytometry. Statistical processing of the obtained data was carried out using the Statistica 7.0 software package (StatSoft, USA). It was found that the activity of aggregation of cells of peripheral venous blood in Arctic residents is 1.5-1.7 times higher than that in people living in more favourable climatic conditions. The frequency of registration of aggregation of erythrocytes and platelets is actually 2 times higher than the aggregation of leukocytes. Aggregation of erythrocytes is associated with an increase in the concentrations of transferrin and receptors for this transport protein. The frequency of detection of platelet aggregation is accompanied by an increase in transferrin concentrations; in cases of aggregation of nonnuclear blood cells, the content of NO2 in the blood serum is increased. Aggregation of neutrophilic granulocytes and lymphocytes is associated with an increase in the content of free adhesion molecules. Aggregation of erythrocytes and platelets is in evidence when it is necessary to trigger reactions of changes in the hemodynamics of microcirculation to increase the efficiency of oxygen and trophic supply of tissues. The adhesion of leukocytes to the endothelium determines the secretion of biologically active substances that contribute to a change in microcirculation and an increase in the migration of leukocytes into tissues for the implementation of phagocytic and cytolytic functions.
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Affiliation(s)
- L. K. Dobrodeeva
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia
| | - A. V. Samodova
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia
| | - S. N. Balashova
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia
| | - K. O. Pashinskaya
- N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia
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Durand M. Large-scale simulations of biological cell sorting driven by differential adhesion follow diffusion-limited domain coalescence regime. PLoS Comput Biol 2021; 17:e1008576. [PMID: 34398883 PMCID: PMC8389523 DOI: 10.1371/journal.pcbi.1008576] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 08/26/2021] [Accepted: 07/06/2021] [Indexed: 12/29/2022] Open
Abstract
Cell sorting, whereby a heterogeneous cell mixture segregates and forms distinct homogeneous tissues, is one of the main collective cell behaviors at work during development. Although differences in interfacial energies are recognized to be a possible driving source for cell sorting, no clear consensus has emerged on the kinetic law of cell sorting driven by differential adhesion. Using a modified Cellular Potts Model algorithm that allows for efficient simulations while preserving the connectivity of cells, we numerically explore cell-sorting dynamics over very large scales in space and time. For a binary mixture of cells surrounded by a medium, increase of domain size follows a power-law with exponent n = 1/4 independently of the mixture ratio, revealing that the kinetics is dominated by the diffusion and coalescence of rounded domains. We compare these results with recent numerical studies on cell sorting, and discuss the importance of algorithmic differences as well as boundary conditions on the observed scaling.
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Affiliation(s)
- Marc Durand
- Université de Paris, CNRS, UMR 7057, Matière et Systèmes Complexes (MSC), Paris, France
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7
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Ma J, Cheng X, Xu Z, Zhang Y, Valle J, Fan S, Zuo X, Lasa I, Fang X. Structural mechanism for modulation of functional amyloid and biofilm formation by Staphylococcal Bap protein switch. EMBO J 2021; 40:e107500. [PMID: 34046916 PMCID: PMC8280801 DOI: 10.15252/embj.2020107500] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 04/26/2021] [Accepted: 04/30/2021] [Indexed: 12/24/2022] Open
Abstract
The Staphylococcal Bap proteins sense environmental signals (such as pH, [Ca2+ ]) to build amyloid scaffold biofilm matrices via unknown mechanisms. We here report the crystal structure of the aggregation-prone region of Staphylococcus aureus Bap which adopts a dumbbell-shaped fold. The middle module (MM) connecting the N-terminal and C-terminal lobes consists of a tandem of novel double-Ca2+ -binding motifs involved in cooperative interaction networks, which undergoes Ca2+ -dependent order-disorder conformational switches. The N-terminal lobe is sufficient to mediate amyloid aggregation through liquid-liquid phase separation and maturation, and subsequent biofilm formation under acidic conditions. Such processes are promoted by disordered MM at low [Ca2+ ] but inhibited by ordered MM stabilized by Ca2+ binding, with inhibition efficiency depending on structural integrity of the interaction networks. These studies illustrate a novel protein switch in pathogenic bacteria and provide insights into the mechanistic understanding of Bap proteins in modulation of functional amyloid and biofilm formation, which could be implemented in the anti-biofilm drug design.
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Affiliation(s)
- Junfeng Ma
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
| | - Xiang Cheng
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
| | - Zhonghe Xu
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
| | - Yikan Zhang
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
| | - Jaione Valle
- Laboratory of Microbial PathogenesisNavarrabiomed‐Universidad Pública de Navarra‐Departamento de SaludIDISNAPamplonaSpain
| | - Shilong Fan
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
| | - Xiaobing Zuo
- X‐ray Science DivisionArgonne National LaboratoryLemontILUSA
| | - Iñigo Lasa
- Laboratory of Microbial PathogenesisNavarrabiomed‐Universidad Pública de Navarra‐Departamento de SaludIDISNAPamplonaSpain
| | - Xianyang Fang
- Beijing Advanced Innovation Center for Structural BiologySchool of Life SciencesTsinghua UniversityBeijingChina
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8
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Chakraborty S, Ray M, Ray S. Bivalve haemocyte adhesion, aggregation and phagocytosis: A tool to reckon arsenic induced threats to freshwater ecosystem. Fish Shellfish Immunol 2021; 114:229-237. [PMID: 33979692 DOI: 10.1016/j.fsi.2021.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/02/2021] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
The freshwater aquifers of the Indo-Gangetic plains support rich biodiversity which is under the threat of arsenic contamination. The filter feeding bivalve mollusc Lamellidens marginalis is a sessile and sentinel resident of these freshwater habitats. In the present study, the classical cell behaviours of adhesion and aggregation were monitored in the circulating haemocytes of the freshwater bivalve under the exposure of sodium arsenite (NaAsO2) at sublethal concentrations in controlled laboratory conditions for a maximum time-span of sixteen days. The toxic metalloid significantly inhibited non-self adhesion, inter-haemocyte interactions and haemocyte aggregation in a dose and time dependent manner. The natural occurrence of the filopods on the haemocytes was significantly diminished in the bivalves exposed to the inorganic arsenite. Moreover, a significant fall in the kinetics of phagocytosis index and haemocyte adhesion was observed under the in vitro exposure to NaAsO2. Compromised non-self adhesion, cell-cell aggregation and phagocytosis of non-self particles by the bivalve haemocytes probably indicate susceptible immunological status of the bivalve. Such vulnerable immunity of the bivalve probably signifies the nature of imminent threat to the freshwater ecosystem as a whole under inorganic arsenite exposure. The findings would be helpful to design bivalve haemocyte based inexpensive biomonitoring tool to assess the health of freshwater ecosystem under potential arsenic threat.
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Affiliation(s)
- Sudipta Chakraborty
- Department of Zoology, Government General Degree College at Keshiary, Paschim Medinipur, PIN 721135, West Bengal, India
| | - Mitali Ray
- Department of Zoology, Aquatic Toxicology Laboratory, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, PIN 700019, West Bengal, India
| | - Sajal Ray
- Department of Zoology, Aquatic Toxicology Laboratory, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, PIN 700019, West Bengal, India.
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9
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Miele L, De Monte S. Aggregative cycles evolve as a solution to conflicts in social investment. PLoS Comput Biol 2021; 17:e1008617. [PMID: 33471791 PMCID: PMC7850506 DOI: 10.1371/journal.pcbi.1008617] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/01/2021] [Accepted: 12/07/2020] [Indexed: 11/18/2022] Open
Abstract
Multicellular organization is particularly vulnerable to conflicts between different cell types when the body forms from initially isolated cells, as in aggregative multicellular microbes. Like other functions of the multicellular phase, coordinated collective movement can be undermined by conflicts between cells that spend energy in fuelling motion and ‘cheaters’ that get carried along. The evolutionary stability of collective behaviours against such conflicts is typically addressed in populations that undergo extrinsically imposed phases of aggregation and dispersal. Here, via a shift in perspective, we propose that aggregative multicellular cycles may have emerged as a way to temporally compartmentalize social conflicts. Through an eco-evolutionary mathematical model that accounts for individual and collective strategies of resource acquisition, we address regimes where different motility types coexist. Particularly interesting is the oscillatory regime that, similarly to life cycles of aggregative multicellular organisms, alternates on the timescale of several cell generations phases of prevalent solitary living and starvation-triggered aggregation. Crucially, such self-organized oscillations emerge as a result of evolution of cell traits associated to conflict escalation within multicellular aggregates. In aggregative multicellular life cycles, cells come together in heterogenous aggregates, whose collective function benefits all the constituent cells. Current explanations for the evolutionary stability of such organization presume that alternating phases of aggregation and dispersal are already in place. Here we propose that, instead of being externally driven, the temporal arrangement of aggregative life cycles may emerge from the interplay between ecology and evolution in populations with differential motility. In our model, cell motility underpins group formation and allows cells to forage individually and collectively. Notably, slower cells can exploit the propulsion by faster cells within multicellular groups. When the level of such exploitation is let evolve, increasing social conflicts are associated to the evolutionary emergence of self-sustained oscillations. Akin to aggregative life cycles, resource exhaustion triggers group formation, whereas conflicts within multicellular groups restrain resource consumption, thus paving the way for the subsequent unicellular phase. The evolutionary transition from equilibrium coexistence to life cycles solves conflicts among heterogenous cell types by integrating them on a timescale longer than cell division, that comes to be associated to multicellular organization.
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Affiliation(s)
- Leonardo Miele
- School of Mathematics, University of Leeds, U.K.
- Institut de Biologie de l’Ecole Normale Supérieure, Département de Biologie, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
- * E-mail: (LM); (SDM)
| | - Silvia De Monte
- Institut de Biologie de l’Ecole Normale Supérieure, Département de Biologie, Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
- Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plőn, Germany
- * E-mail: (LM); (SDM)
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Poplimont H, Georgantzoglou A, Boulch M, Walker HA, Coombs C, Papaleonidopoulou F, Sarris M. Neutrophil Swarming in Damaged Tissue Is Orchestrated by Connexins and Cooperative Calcium Alarm Signals. Curr Biol 2020; 30:2761-2776.e7. [PMID: 32502410 PMCID: PMC7372224 DOI: 10.1016/j.cub.2020.05.030] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/30/2020] [Accepted: 05/07/2020] [Indexed: 12/19/2022]
Abstract
Neutrophils are major inflammatory cells that rapidly infiltrate wounds to provide antimicrobial functions. Within the damaged tissue, neutrophil migration behavior often switches from exploratory patrolling to coordinated swarming, giving rise to dense clusters that further disrupt tissue architecture. This aggregation response is self-organized by neutrophil paracrine chemoattractant signaling (most notably of the inflammatory mediator leukotriene B4 [LTB4]). The coordination mechanism and possible evolutionary benefits of neutrophil swarms are elusive. Here, we show that neutrophil swarms require mutual reinforcement of damage signaling at the wound core. New biosensors and live imaging in zebrafish revealed that neutrophil chemoattractant synthesis is triggered by a sustained calcium flux upon contact with necrotic tissue that requires sensing of the damage signal ATP. This "calcium alarm" signal rapidly propagates in the nascent neutrophil cluster in a contact-dependent manner via connexin-43 (Cx43) hemichannels, which are mediators of active ATP release. This enhances chemoattractant biosynthesis in the growing cluster, which is instrumental for coordinated motion and swarming. Inhibition of neutrophil Cx43 compromises clearance of wound-colonizing P. aeruginosa bacteria and exacerbates infection-induced morbidity. Thus, cooperative production of alarm signals among pioneer clustering neutrophils fuels the growth of dense antimicrobial cell masses that effectively seal off breached tissue barriers from opportunistic pathogens.
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Affiliation(s)
- Hugo Poplimont
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Antonios Georgantzoglou
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Morgane Boulch
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Hazel A Walker
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Caroline Coombs
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Foteini Papaleonidopoulou
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK
| | - Milka Sarris
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge CB2 3DY, UK.
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11
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Noubouossie DF, Henderson MW, Mooberry M, Ilich A, Ellsworth P, Piegore M, Skinner SC, Pawlinski R, Welsby I, Renné T, Hoffman M, Monroe DM, Key NS. Red blood cell microvesicles activate the contact system, leading to factor IX activation via 2 independent pathways. Blood 2020; 135:755-765. [PMID: 31971571 PMCID: PMC7059516 DOI: 10.1182/blood.2019001643] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 01/08/2020] [Indexed: 01/01/2023] Open
Abstract
Storage lesion-induced, red cell-derived microvesicles (RBC-MVs) propagate coagulation by supporting the assembly of the prothrombinase complex. It has also been reported that RBC-MVs initiate coagulation via the intrinsic pathway. To elucidate the mechanism(s) of RBC-MV-induced coagulation activation, the ability of storage lesion-induced RBC-MVs to activate each zymogen of the intrinsic pathway was assessed in a buffer system. Simultaneously, the thrombin generation (TG) assay was used to assess their ability to initiate coagulation in plasma. RBC-MVs directly activated factor XII (FXII) or prekallikrein, but not FXI or FIX. RBC-MVs initiated TG in normal pooled plasma and in FXII- or FXI-deficient plasma, but not in FIX-deficient plasma, suggesting an alternate pathway that bypasses both FXII and FXI. Interestingly, RBC-MVs generated FIXa in a prekallikrein-dependent manner. Similarly, purified kallikrein activated FIX in buffer and initiated TG in normal pooled plasma, as well as FXII- or FXI-deficient plasma, but not FIX-deficient plasma. Dual inhibition of FXIIa by corn trypsin inhibitor and kallikrein by soybean trypsin inhibitor was necessary for abolishing RBC-MV-induced TG in normal pooled plasma, whereas kallikrein inhibition alone was sufficient to abolish TG in FXII- or FXI-deficient plasma. Heating RBC-MVs at 60°C for 15 minutes or pretreatment with trypsin abolished TG, suggesting the presence of MV-associated proteins that are essential for contact activation. In summary, RBC-MVs activate both FXII and prekallikrein, leading to FIX activation by 2 independent pathways: the classic FXIIa-FXI-FIX pathway and direct kallikrein activation of FIX. These data suggest novel mechanisms by which RBC transfusion mediates inflammatory and/or thrombotic outcomes.
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Affiliation(s)
| | - Michael W Henderson
- UNC Blood Research Center, and
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | | | - Anton Ilich
- Department of Medicine
- UNC Blood Research Center, and
| | - Patrick Ellsworth
- Department of Medicine
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Mark Piegore
- Department of Medicine
- UNC Blood Research Center, and
| | - Sarah C Skinner
- Department of Medicine
- UNC Blood Research Center, and
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | | | - Ian Welsby
- Department of Anesthesiology, Duke University, Durham, NC
| | - Thomas Renné
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; and
| | - Maureane Hoffman
- Department of Pathology, Veteran Affairs Medical Center, Durham, NC
| | | | - Nigel S Key
- Department of Medicine
- UNC Blood Research Center, and
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
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12
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Abstract
Cancer is a complex phenomenon, and the sheer variation in behaviour across different types renders it difficult to ascertain underlying biological mechanisms. Experimental approaches frequently yield conflicting results for myriad reasons, and mathematical modelling of cancer is a vital tool to explore what we cannot readily measure, and ultimately improve treatment and prognosis. Like experiments, models are underpinned by certain biological assumptions, variation of which can lead to divergent predictions. An outstanding and important question concerns contact inhibition of proliferation (CIP), the observation that proliferation ceases when cells are spatially confined by their neighbours. CIP is a characteristic of many healthy adult tissues, but it remains unclear to which extent it holds in solid tumours, which exhibit regions of hyper-proliferation, and apparent breakdown of CIP. What precisely occurs in tumour tissue remains an open question, which mathematical modelling can help shed light on. In this perspective piece, we explore the implications of different hypotheses and available experimental evidence to elucidate the implications of these scenarios. We also outline how erroneous conclusions about the nature of tumour growth may be arrived at by looking selectively at biological data in isolation, and how this might be circumvented.
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Affiliation(s)
- David Robert Grimes
- School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
- Department of Oncology, University of Oxford, Old Road Campus, Oxford, OX3 7DQ, UK.
| | - Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, S3 7RH, UK
- Bateson Centre, University of Sheffield, Sheffield, S10 2TN, UK
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13
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Rens EG, Edelstein-Keshet L. From energy to cellular forces in the Cellular Potts Model: An algorithmic approach. PLoS Comput Biol 2019; 15:e1007459. [PMID: 31825952 PMCID: PMC6927661 DOI: 10.1371/journal.pcbi.1007459] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 12/23/2019] [Accepted: 10/05/2019] [Indexed: 11/30/2022] Open
Abstract
Single and collective cell dynamics, cell shape changes, and cell migration can be conveniently represented by the Cellular Potts Model, a computational platform based on minimization of a Hamiltonian. Using the fact that a force field is easily derived from a scalar energy (F = −∇H), we develop a simple algorithm to associate effective forces with cell shapes in the CPM. We predict the traction forces exerted by single cells of various shapes and sizes on a 2D substrate. While CPM forces are specified directly from the Hamiltonian on the cell perimeter, we approximate the force field inside the cell domain using interpolation, and refine the results with smoothing. Predicted forces compare favorably with experimentally measured cellular traction forces. We show that a CPM model with internal signaling (such as Rho-GTPase-related contractility) can be associated with retraction-protrusion forces that accompany cell shape changes and migration. We adapt the computations to multicellular systems, showing, for example, the forces that a pair of swirling cells exert on one another, demonstrating that our algorithm works equally well for interacting cells. Finally, we show forces exerted by cells on one another in classic cell-sorting experiments. Cells exert forces on their surroundings and on one another. In simulations of cell shape using the Cellular Potts Model (CPM), the dynamics of deforming cell shapes is traditionally represented by an energy-minimization method. We use this CPM energy, the Hamiltonian, to derive and visualize the corresponding forces exerted by the cells. We use the fact that force is the negative gradient of energy to assign forces to the CPM cell edges, and then extend the results to approximate interior forces by interpolation. We show that this method works for single as well as multiple interacting model cells, both static and motile. Finally, we show favorable comparison between predicted forces and real forces measured experimentally.
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Affiliation(s)
- Elisabeth G. Rens
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Leah Edelstein-Keshet
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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14
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Sheremet'ev YA, Popovicheva AN, Rogozin MM, Levin GY. Red blood cell aggregation, disaggregation and aggregate morphology in autologous plasma and serum in diabetic foot disease. Clin Hemorheol Microcirc 2019; 72:221-227. [PMID: 30909193 DOI: 10.3233/ch-180405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Diabetes mellitus is frequently associated with microcirculation pathology and hemorheological disorders. METHODS 24 patients with diabetic foot and 22 healthy subjects were recruited. RBC aggregation, disaggregation and morphology of aggregates were determined in autologous plasma and serum. RESULTS The RBC aggregation in patients with diabetic foot increased in autologous plasma and serum. Increased red blood cell aggregate strength in these patients was observed only in autologous plasma. Microscopic images of RBC aggregates of patients with diabetic foot show the formation of pathologic globular structures of aggregates in autologous plasma and serum. CONCLUSION The RBC aggregation in autologous plasma and autologous serum in patients with diabetic foot is significantly higher than in healthy subjects. Increase in strength of RBC aggregates in diabetic foot patients was observed only in autologous plasma. The microscopic images of RBC aggregates in patients with diabetic foot indicate the formation of globular (pathologic) structures of aggregates in autologous plasma and serum. The differences in the morphology of RBC aggregates in autologous plasma and serum between healthy subjects and diabetic foot patients, obtained by microscopic image analysis with high magnification light microscope, can be used as an additional diagnostic tool in medical practice.
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15
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de Carpentier F, Lemaire SD, Danon A. When Unity Is Strength: The Strategies Used by Chlamydomonas to Survive Environmental Stresses. Cells 2019; 8:E1307. [PMID: 31652831 PMCID: PMC6912462 DOI: 10.3390/cells8111307] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 12/21/2022] Open
Abstract
The unicellular green alga Chlamydomonas reinhardtii is a valuable model system to study a wide spectrum of scientific fields, including responses to environmental conditions. Most studies are performed under optimal growth conditions or under mild stress. However, when environmental conditions become harsher, the behavior of this unicellular alga is less well known. In this review we will show that despite being a unicellular organism, Chlamydomonas can survive very severe environmental conditions. To do so, and depending on the intensity of the stress, the strategies used by Chlamydomonas can range from acclimation to the formation of multicellular structures, or involve programmed cell death.
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Affiliation(s)
- Félix de Carpentier
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France.
- Faculty of Sciences, Doctoral School of Plant Sciences, Université Paris-Sud, Paris-Saclay, 91400 Orsay, France.
| | - Stéphane D Lemaire
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France.
| | - Antoine Danon
- Institut de Biologie Physico-Chimique, UMR 8226, CNRS, Sorbonne Université, 75005 Paris, France.
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16
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Nakao M, Imashiro C, Kuribara T, Kurashina Y, Totani K, Takemura K. Formation of Large Scaffold-Free 3-D Aggregates in a Cell Culture Dish by Ultrasound Standing Wave Trapping. Ultrasound Med Biol 2019; 45:1306-1315. [PMID: 30799124 DOI: 10.1016/j.ultrasmedbio.2019.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 12/25/2018] [Accepted: 01/15/2019] [Indexed: 05/06/2023]
Abstract
Cellular aggregates that mimic cell-cell interactions in vitro are essential for biological research. This study introduces a method to form large scaffold-free 3-D aggregates in a clinically ubiquitous cell culture dish using kilohertz-order ultrasound standing wave trapping (USWT). We fabricated an aggregate formation system in which a 60-mm dish was set above a Langevin transducer via water. The transducer was excited at 110.8 kHz, and then C2C12 myoblasts were injected into the dish and trapped at the node position of the standing wave. The diameter and thickness of the formed aggregate were 8 and 2.7 mm, respectively, which are larger than those of aggregates formed previously by USWT. Moreover, we confirmed that >94% of cells constituting the aggregates survived 9 h, and the protein expression of cells was not altered significantly. This method can be applied to form aggregates with high functionality, which contributes to the development of biological research methodology.
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Affiliation(s)
- Misa Nakao
- School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, Yokohama, Kanagawa, Japan
| | - Chikahiro Imashiro
- School of Science for Open and Environmental Systems, Graduate School of Science and Technology, Keio University, Yokohama, Kanagawa, Japan
| | - Taiki Kuribara
- Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, Musashino, Tokyo, Japan
| | - Yuta Kurashina
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan 226-8503; Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, Japan
| | - Kiichiro Totani
- Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, Musashino, Tokyo, Japan
| | - Kenjiro Takemura
- Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, Yokohama, Kanagawa, Japan.
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17
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Bijonowski BM, Daraiseh SI, Yuan X, Ma T. Size-Dependent Cortical Compaction Induces Metabolic Adaptation in Mesenchymal Stem Cell Aggregates. Tissue Eng Part A 2019; 25:575-587. [PMID: 30187829 PMCID: PMC6482905 DOI: 10.1089/ten.tea.2018.0155] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 08/31/2018] [Indexed: 01/01/2023] Open
Abstract
IMPACT STATEMENT This study reveals that multicellular aggregation induces metabolic reprogramming via mechanical compaction in lieu of formation of a hypoxic core. Utilizing biomechanical knowledge gained from planar culture, we set forth a novel three-dimensional (3D) model of size-dependent cortical compaction and demonstrated its role in metabolic reconfiguration. Ultimately, this study establishes mechanical compaction and its spatial gradients as key regulatory factors and design parameters in the development of 3D human adipose-derived mesenchymal stem cell aggregates.
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Affiliation(s)
- Brent M. Bijonowski
- Dept. of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida
| | - Susan I. Daraiseh
- Dept. of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida
| | - Xuegang Yuan
- Dept. of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida
| | - Teng Ma
- Dept. of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee, Florida
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18
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B. George A, Korolev KS. Chirality provides a direct fitness advantage and facilitates intermixing in cellular aggregates. PLoS Comput Biol 2018; 14:e1006645. [PMID: 30589836 PMCID: PMC6307711 DOI: 10.1371/journal.pcbi.1006645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 11/15/2018] [Indexed: 12/23/2022] Open
Abstract
Chirality in shape and motility can evolve rapidly in microbes and cancer cells. To determine how chirality affects cell fitness, we developed a model of chiral growth in compact aggregates such as microbial colonies and solid tumors. Our model recapitulates previous experimental findings and shows that mutant cells can invade by increasing their chirality or switching their handedness. The invasion results either in a takeover or stable coexistence between the mutant and the ancestor depending on their relative chirality. For large chiralities, the coexistence is accompanied by strong intermixing between the cells, while spatial segregation occurs otherwise. We show that the competition within the aggregate is mediated by bulges in regions where the cells with different chiralities meet. The two-way coupling between aggregate shape and natural selection is described by the chiral Kardar-Parisi-Zhang equation coupled to the Burgers’ equation with multiplicative noise. We solve for the key features of this theory to explain the origin of selection on chirality. Overall, our work suggests that chirality could be an important ecological trait that mediates competition, invasion, and spatial structure in cellular populations. Is it better to be left- or right-handed? The answer depends on whether the goal is making a handshake or winning a boxing match. The need for coordination favors the handedness of the majority, but being different could also provide an advantage. The same rules could apply to microbial colonies and cancer tumors. Like humans, cells often have handedness (chirality) that reflects the lack of mirror symmetry in their shapes or movement patterns. We find that cells gain a substantial fitness advantage by either increasing the magnitude of their chirality or switching to the opposite handedness. Selection for specific chirality can overcome differences in growth rate and is mediated by the formation of bulges along the colony edge in regions where cells with different chiralities meet.
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Affiliation(s)
- Ashish B. George
- Department of Physics, Boston University, Boston, Massachusetts, United States of America
- * E-mail: (ABG); (KSK)
| | - Kirill S. Korolev
- Department of Physics and Graduate Program in Bioinformatics, Boston University, Boston, Massachusetts, United States of America
- * E-mail: (ABG); (KSK)
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19
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Chen HY, Hsiao YT, Liu SC, Hsu T, Woon WY, I L. Enhancing Cancer Cell Collective Motion and Speeding up Confluent Endothelial Dynamics through Cancer Cell Invasion and Aggregation. Phys Rev Lett 2018; 121:018101. [PMID: 30028147 DOI: 10.1103/physrevlett.121.018101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 04/03/2018] [Indexed: 06/08/2023]
Abstract
We report the experimental observation of speeded-up collective motion of the monolayer endothelia-cancer mixture on a collagen-coated substrate, after the invasion of a small fraction of motile cancer cells into the confluent endothelial monolayer, through disrupting cell-cell junctions. It is found that, with an increasing waiting time, the cancer-free confluent endothelial monolayer exhibits a dynamical slowing-down of liquidlike micromotion with a gradually decreasing degree of superdiffusion. After invasion, cancer cells aggregate and exhibit turbulentlike cooperative motion, which is enhanced with the increasing size of gradually aggregated cancer clusters, confined by the fluctuating boundaries of surrounding endothelial cells. It, in turn, enhances the surrounding endothelial cell motion and speeds up the originally slowed-down motion.
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Affiliation(s)
- Hsiang-Ying Chen
- Department of Physics and Center for Complex Systems, National Central University, Jhongli, Taiwan 32001, Republic of China
| | - Yi-Teng Hsiao
- Department of Physics and Center for Complex Systems, National Central University, Jhongli, Taiwan 32001, Republic of China
| | - Shu-Chen Liu
- Department of Biomedical Sciences and Engineering, National Central University, Jhongli, Taiwan 32001, Republic of China
| | - Tien Hsu
- Department of Biomedical Sciences and Engineering, National Central University, Jhongli, Taiwan 32001, Republic of China
| | - Wei-Yen Woon
- Department of Physics and Center for Complex Systems, National Central University, Jhongli, Taiwan 32001, Republic of China
| | - Lin I
- Department of Physics and Center for Complex Systems, National Central University, Jhongli, Taiwan 32001, Republic of China
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20
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Sussman DM, Schwarz JM, Marchetti MC, Manning ML. Soft yet Sharp Interfaces in a Vertex Model of Confluent Tissue. Phys Rev Lett 2018; 120:058001. [PMID: 29481188 DOI: 10.1103/physrevlett.120.058001] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Indexed: 06/08/2023]
Abstract
How can dense biological tissue maintain sharp boundaries between coexisting cell populations? We explore this question within a simple vertex model for cells, focusing on the role of topology and tissue surface tension. We show that the ability of cells to independently regulate adhesivity and tension, together with neighbor-based interaction rules, lets them support strikingly unusual interfaces. In particular, we show that mechanical- and fluctuation-based measurements of the effective surface tension of a cellular aggregate yield different results, leading to mechanically soft interfaces that are nevertheless extremely sharp.
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Affiliation(s)
- Daniel M Sussman
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - J M Schwarz
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - M Cristina Marchetti
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
| | - M Lisa Manning
- Department of Physics and Soft Matter Program, Syracuse University, Syracuse, New York 13244, USA
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21
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Jackson-Holmes EL, McDevitt TC, Lu H. A microfluidic trap array for longitudinal monitoring and multi-modal phenotypic analysis of individual stem cell aggregates. Lab Chip 2017; 17:3634-3642. [PMID: 28952622 PMCID: PMC5656523 DOI: 10.1039/c7lc00763a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Three-dimensional pluripotent stem cell (PSC) cultures have the ability to undergo differentiation, self-organization, and morphogenesis to yield complex, in vitro tissue models that recapitulate key elements of native tissues. These tissue models offer a system for studying mechanisms of tissue development, investigating disease mechanisms, and performing drug screening. It remains challenging, however, to standardize PSC aggregate differentiation and morphogenesis methods due to heterogeneity stemming from biological and environmental sources. It is also difficult to monitor and assess large numbers of individual samples longitudinally throughout culture using typical batch-based culture methods. To address these challenges, we have developed a microfluidic platform for culture, longitudinal monitoring, and phenotypic analysis of individual stem cell aggregates. This platform uses a hydrodynamic loading principle to capture pre-formed stem cell aggregates in independent traps. We demonstrated that multi-day culture of aggregates in this platform reduces heterogeneity in phenotypic parameters such as size and morphology. Additionally, we showed that culture and analysis steps can be performed sequentially in the same platform, enabling correlation of multiple modes of analysis for individual samples. We anticipate this platform being applied to improve abilities for phenotypic analysis of PSC aggregate tissues and to facilitate research in standardizing culture systems in order to dually increase the yield and reduce the heterogeneity of PSC-derived tissues.
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Affiliation(s)
- E L Jackson-Holmes
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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22
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Pachano T, Nievas YR, Lizarraga A, Johnson PJ, Strobl-Mazzulla PH, de Miguel N. Epigenetics regulates transcription and pathogenesis in the parasite Trichomonas vaginalis. Cell Microbiol 2017; 19:e12716. [PMID: 28054438 DOI: 10.1111/cmi.12716] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 11/14/2016] [Accepted: 12/21/2016] [Indexed: 12/21/2022]
Abstract
Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Different T. vaginalis strains vary greatly in their adherence and cytolytic capacities. These phenotypic differences might be attributed to differentially expressed genes as a consequence of extra-genetic variation, such as epigenetic modifications. In this study, we explored the role of histone acetylation in regulating gene transcription and pathogenesis in T. vaginalis. Here, we show that histone 3 lysine acetylation (H3KAc) is enriched in nucleosomes positioned around the transcription start site of active genes (BAP1 and BAP2) in a highly adherent parasite strain; compared with the low acetylation abundance in contrast to that observed in a less-adherent strain that expresses these genes at low levels. Additionally, exposition of less-adherent strain with a specific histone deacetylases inhibitor, trichostatin A, upregulated the transcription of BAP1 and BAP2 genes in concomitance with an increase in H3KAc abundance and chromatin accessibility around their transcription start sites. Moreover, we demonstrated that the binding of initiator binding protein, the transcription factor responsible for the initiation of transcription of ~75% of known T. vaginalis genes, depends on the histone acetylation state around the metazoan-like initiator to which initiator binding protein binds. Finally, we found that trichostatin A treatment increased parasite aggregation and adherence to host cells. Our data demonstrated for the first time that H3KAc is a permissive histone modification that functions to mediate both transcription and pathogenesis of the parasite T. vaginalis.
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Affiliation(s)
- Tomas Pachano
- Laboratorio de Parásitos Anaerobios, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina
| | - Yesica R Nievas
- Laboratorio de Parásitos Anaerobios, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina
| | - Ayelen Lizarraga
- Laboratorio de Parásitos Anaerobios, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina
| | - Patricia J Johnson
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Pablo H Strobl-Mazzulla
- Laboratorio de Biología del Desarrollo, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina
| | - Natalia de Miguel
- Laboratorio de Parásitos Anaerobios, Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús (IIB-INTECH), CONICET-UNSAM, Chascomús, Argentina
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23
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Tam SN, Smith ML, Stamenović D. Modeling tensional homeostasis in multicellular clusters. Int J Numer Method Biomed Eng 2017; 33. [PMID: 27163337 DOI: 10.1002/cnm.2801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 04/27/2016] [Accepted: 04/29/2016] [Indexed: 06/05/2023]
Abstract
Homeostasis of mechanical stress in cells, or tensional homeostasis, is essential for normal physiological function of tissues and organs and is protective against disease progression, including atherosclerosis and cancer. Recent experimental studies have shown that isolated cells are not capable of maintaining tensional homeostasis, whereas multicellular clusters are, with stability increasing with the size of the clusters. Here, we proposed simple mathematical models to interpret experimental results and to obtain insight into factors that determine homeostasis. Multicellular clusters were modeled as one-dimensional arrays of linearly elastic blocks that were either jointed or disjointed. Fluctuating forces that mimicked experimentally measured cell-substrate tractions were obtained from Monte Carlo simulations. These forces were applied to the cluster models, and the corresponding stress field in the cluster was calculated by solving the equilibrium equation. It was found that temporal fluctuations of the cluster stress field became attenuated with increasing cluster size, indicating that the cluster approached tensional homeostasis. These results were consistent with previously reported experimental data. Furthermore, the models revealed that key determinants of tensional homeostasis in multicellular clusters included the cluster size, the distribution of traction forces, and mechanical coupling between adjacent cells. Based on these findings, we concluded that tensional homeostasis was a multicellular phenomenon. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Sze Nok Tam
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Michael L Smith
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Dimitrije Stamenović
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Division of Material Science and Engineering, Boston University, Brookline, MA 02446, USA
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24
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Chen Y, Yu C, Cao H, Li L. [Effect of shift rotation culture on formation and activity of encapsulated hepatocytes aggregates]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2016; 45:403-409. [PMID: 27868414 PMCID: PMC10396877 DOI: 10.3785/j.issn.1008-9292.2016.07.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Objective: To observe the effect of uniform and shift rotation culture on the formation and activity of the alginate-chitosan (AC) microencapsulated HepLL immortalized human hepatocytes and HepG2 cells aggregates. Methods: AC microcapsulated HepG2 and HepLL cells were randomly divided into two groups. Each group was divided into 3 subgroups according to uniform and shift rotation culture.The size and number of aggregates were observed and measured under laser confocal microscopy and inverted microscope dynamically. The amount of albumin synthesis was detected by ELISA, the clearance of ammonia was detected by colorimetry, and diazepam conversion function was detected by high performance liquid chromatography (HPLC). Results: On day 6, 8, 10, 12, 14 and 16, the number and size of the aggregates, albumin synthesis, diazepam clearance and ammonium clearance increased significantly in shift rotation culture group than in uniform group (all P<0.01). The albumin synthesis, diazepam clearance, and ammonium clearance in the microencapsulated HepLL groups were significantly higher than those of HepG2 cells at any time (all P<0.01). Conclusion: Shift rotation culture can significantly promote the formation and increase the activity of AC microencapsulated HepLL and HepG2 aggregates, and HepLL cells may be more suitable for bioartificial liver than HepG2.
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Affiliation(s)
- Yanshan Chen
- Department of Infectious Diseases, the First Affiliated Hospital, Xiamen University, Xiamen 361000, China;State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Infectious Disease, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Chengbo Yu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Infectious Disease, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Hongcui Cao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Infectious Disease, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Lanjuan Li
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Department of Infectious Disease, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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25
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Abstract
The crawling of biological cell is a complex phenomenon involving various biochemical and mechanical processes. Some of these processes are intrinsic to individual cells, while others pertain to cell-to-cell interactions and to their responses to extrinsically imposed cues. Here, we report an interesting aggregation dynamics of mathematical model cells, when they perform chemotaxis in response to an externally imposed global chemical gradient while they influence each other through a haptotaxis-mediated social interaction, which confers intriguing trail patterns. In the absence of the cell-to-cell interaction, the equilibrium population density profile fits well to that of a simple Keller-Segal population dynamic model, in which a chemotactic current density J→chemo∼∇p competes with a normal diffusive current density J→diff∼∇ρ, where p and ρ refer to the concentration of chemoattractant and population density, respectively. We find that the cell-to-cell interaction confers a far more compact aggregation resulting in a much higher peak equilibrium cell density. The mathematical model system is applicable to many biological systems such as swarming microglia and neutrophils or accumulating ants towards a localized food source.
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Affiliation(s)
- Tae-goo Kwon
- Department of Physics, Korea University, Seoul 136-713, Korea
| | | | - Kyoung J. Lee
- Department of Physics, Korea University, Seoul 136-713, Korea
- * E-mail:
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26
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Feng G, Sullivan DP, Han F, Muller WA. Segregation of VE-cadherin from the LBRC depends on the ectodomain sequence required for homophilic adhesion. J Cell Sci 2016; 128:576-88. [PMID: 25501813 DOI: 10.1242/jcs.159053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The lateral border recycling compartment (LBRC) is a reticulum ofperijunctional tubulovesicular membrane that is continuous with the plasmalemma of endothelial cells and is essential for efficient transendothelial migration (TEM) of leukocytes. The LBRC contains molecules involved in TEM, such as PECAM, PVR and CD99, but not VE-cadherin. Despite its importance, how membrane proteins are included in or excluded from the LBRC is not known. Immunoelectronmicroscopy and biochemical approaches demonstrate that inclusion into the LBRC is the default pathway for transmembrane molecules present at endothelial cell borders. A chimeric molecule composed of the extracellular domain of VE-cadherin and cytoplasmic tail of PECAM (VE-CAD/PECAM) did not enter the LBRC, suggesting that VE-cadherin was excluded by a mechanism involving its extracellular domain. Deletion of the homophilic interaction domain EC1 or the homophilic interaction motif RVDAE allowed VE-CAD/PECAM and even native VE-cadherin to enter the LBRC. Similarly, treatment with RVDAE peptide to block homophilic VE-cadherin interactions allowed endogenous VE-cadherin to enter the LBRC. This suggests that homophilic interactions of VE-cadherin stabilize it at cell borders and prevent entry into the LBRC.
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Buono MJ, Krippes T, Kolkhorst FW, Williams AT, Cabrales P. Increases in core temperature counterbalance effects of haemoconcentration on blood viscosity during prolonged exercise in the heat. Exp Physiol 2016; 101:332-42. [PMID: 26682653 PMCID: PMC4738148 DOI: 10.1113/ep085504] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/15/2015] [Indexed: 01/11/2023]
Abstract
NEW FINDINGS What is the central question of this study? The purpose of the present study was to determine the effects of exercise-induced haemoconcentration and hyperthermia on blood viscosity. What is the main finding and its importance? Exercise-induced haemoconcentration, increased plasma viscosity and increased blood aggregation, all of which increased blood viscosity, were counterbalanced by increased red blood cell (RBC) deformability (e.g. RBC membrane shear elastic modulus and elongation index) caused by the hyperthermia. Thus, blood viscosity remained unchanged following prolonged moderate-intensity exercise in the heat. Previous studies have reported that blood viscosity is significantly increased following exercise. However, these studies measured both pre- and postexercise blood viscosity at 37 °C even though core and blood temperatures would be expected to have increased during the exercise. Consequently, the effect of exercise-induced hyperthermia on mitigating change in blood viscosity may have been missed. The purpose of this study was to isolate the effects of exercise-induced haemoconcentration and hyperthermia and to determine their combined effects on blood viscosity. Nine subjects performed 2 h of moderate-intensity exercise in the heat (37 °C, 40% relative humidity), which resulted in significant increases from pre-exercise values for rectal temperature (from 37.11 ± 0.35 to 38.76 ± 0.13 °C), haemoconcentration (haematocrit increased from 43.6 ± 3.6 to 45.6 ± 3.5%) and dehydration (change in body weight = -3.6 ± 0.7%). Exercise-induced haemoconcentration significantly (P < 0.05) increased blood viscosity by 9% (from 3.97 to 4.33 cP at 300 s(-1)), whereas exercise-induced hyperthermia significantly decreased blood viscosity by 7% (from 3.97 to 3.69 cP at 300 s(-1)). When both factors were considered together, there was no overall change in blood viscosity (from 3.97 to 4.03 cP at 300 s(-1)). The effects of exercise-induced haemoconcentration, increased plasma viscosity and increased red blood cell aggregation, all of which increased blood viscosity, were counterbalanced by increased red blood cell deformability (e.g. red blood cell membrane shear elastic modulus and elongation index) caused by the hyperthermia. Thus, blood viscosity remained unchanged following prolonged moderate-intensity exercise in the heat.
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Affiliation(s)
- Michael J. Buono
- Department of Biology, San Diego State University, San Diego, CA 92182
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92182
| | - Taylor Krippes
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92182
| | - Fred W. Kolkhorst
- School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92182
| | - Alexander T. Williams
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093
| | - Pedro Cabrales
- Department of Bioengineering, University of California, San Diego, San Diego, CA 92093
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28
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Zavalishina SY, Medvedev IN. [Features aggregation erythrocytes and platelets in old rats experiencing regular exercise on a treadmill]. Adv Gerontol 2016; 29:437-441. [PMID: 28525691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We estimated the age dynamics of aggregation properties of platelets and red blood cells in aged rats on the background of regular muscle loads. The study was performed on 26 male rats of 12 months of age, experience during the year, daily exercise. Control is represented by 91 healthy male rats: 30 individuals (12 months), 32 rats (18 months) and 29 rats (24 months). Applied biochemistry, hematology and statistical methods. The gradual increase in control observed with age, and the erythrocyte aggregation properties of platelets. In experimental animals observed retention of activity aggregation of platelets and red blood cells at a level close to the end during the whole period of regular muscle loads.
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Affiliation(s)
- S Yu Zavalishina
- Kursk Institute of Social Education (branch) of Russian State Social University, Kursk, 305029, Russian Federation;
| | - I N Medvedev
- Kursk Institute of Social Education (branch) of Russian State Social University, Kursk, 305029, Russian Federation;
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29
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Soumya SS, Gupta A, Cugno A, Deseri L, Dayal K, Das D, Sen S, Inamdar MM. Coherent Motion of Monolayer Sheets under Confinement and Its Pathological Implications. PLoS Comput Biol 2015; 11:e1004670. [PMID: 26691341 PMCID: PMC4686989 DOI: 10.1371/journal.pcbi.1004670] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 11/23/2015] [Indexed: 11/26/2022] Open
Abstract
Coherent angular rotation of epithelial cells is thought to contribute to many vital physiological processes including tissue morphogenesis and glandular formation. However, factors regulating this motion, and the implications of this motion if perturbed, remain incompletely understood. In the current study, we address these questions using a cell-center based model in which cells are polarized, motile, and interact with the neighboring cells via harmonic forces. We demonstrate that, a simple evolution rule in which the polarization of any cell tends to orient with its velocity vector can induce coherent motion in geometrically confined environments. In addition to recapitulating coherent rotational motion observed in experiments, our results also show the presence of radial movements and tissue behavior that can vary between solid-like and fluid-like. We show that the pattern of coherent motion is dictated by the combination of different physical parameters including number density, cell motility, system size, bulk cell stiffness and stiffness of cell-cell adhesions. We further observe that perturbations in the form of cell division can induce a reversal in the direction of motion when cell division occurs synchronously. Moreover, when the confinement is removed, we see that the existing coherent motion leads to cell scattering, with bulk cell stiffness and stiffness of cell-cell contacts dictating the invasion pattern. In summary, our study provides an in-depth understanding of the origin of coherent rotation in confined tissues, and extracts useful insights into the influence of various physical parameters on the pattern of such movements. Epithelial and endothelial cells that line various cavities and the vasculature in our bodies, are tightly connected to each other and exist as sheets. Upon confinement in two-dimensional geometries, these cells exhibit rotational motion, which has also been observed in vivo and implicated in physiological processes. However, how this rotational motion is achieved remains unclear. We show that a simple rule wherein preferred direction of motion (i.e., polarization) of cells tends to align with the direction of their velocity is sufficient to induce such coherent movement in confined geometries. We also show that the number of cells within the confinement, the size of the tissue, cell motility and physical properties of the cell and cell-cell connections regulate this coherent motion, and the pattern of invasion when the confinement is relaxed.
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Affiliation(s)
- S S Soumya
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Animesh Gupta
- Department of Physics, Indian Institute of Technology Bombay, Mumbai, India
| | - Andrea Cugno
- DICAM-Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy
| | - Luca Deseri
- DICAM-Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy
| | - Kaushik Dayal
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Dibyendu Das
- Department of Physics, Indian Institute of Technology Bombay, Mumbai, India
| | - Shamik Sen
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Mandar M. Inamdar
- Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India
- * E-mail:
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30
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Song W, Lu YC, Frankel AS, An D, Schwartz RE, Ma M. Engraftment of human induced pluripotent stem cell-derived hepatocytes in immunocompetent mice via 3D co-aggregation and encapsulation. Sci Rep 2015; 5:16884. [PMID: 26592180 PMCID: PMC4655358 DOI: 10.1038/srep16884] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 10/01/2015] [Indexed: 12/17/2022] Open
Abstract
Cellular therapies for liver diseases and in vitro models for drug testing both require functional human hepatocytes (Hum-H), which have unfortunately been limited due to the paucity of donor liver tissues. Human pluripotent stem cells (hPSCs) represent a promising and potentially unlimited cell source to derive Hum-H. However, the hepatic functions of these hPSC-derived cells to date are not fully comparable to adult Hum-H and are more similar to fetal ones. In addition, it has been challenging to obtain functional hepatic engraftment of these cells with prior studies having been done in immunocompromised animals. In this report, we demonstrated successful engraftment of human induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (iPS-H) in immunocompetent mice by pre-engineering 3D cell co-aggregates with stromal cells (SCs) followed by encapsulation in recently developed biocompatible hydrogel capsules. Notably, upon transplantation, human albumin and α1-antitrypsin (A1AT) in mouse sera secreted by encapsulated iPS-H/SCs aggregates reached a level comparable to the primary Hum-H/SCs control. Further immunohistochemistry of human albumin in retrieved cell aggregates confirmed the survival and function of iPS-H. This proof-of-concept study provides a simple yet robust approach to improve the engraftment of iPS-H, and may be applicable to many stem cell-based therapies.
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Affiliation(s)
- Wei Song
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Yen-Chun Lu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Angela S. Frankel
- Division of Gastroenterology & Hepatology, Department of Medicine, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Duo An
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA
| | - Robert E. Schwartz
- Division of Gastroenterology & Hepatology, Department of Medicine, Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA
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Jayawardana KW, Wijesundera SA, Yan M. Aggregation-based detection of M. smegmatis using D-arabinose-functionalized fluorescent silica nanoparticles. Chem Commun (Camb) 2015; 51:15964-6. [PMID: 26379182 PMCID: PMC4618767 DOI: 10.1039/c5cc05772h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluorescein-doped silica nanoparticles (FSNPs) functionalized with D-arabinose (Ara) showed strong interactions with Mycobacterium smegmatis (M. smegmatis) and caused the bacteria to aggregate. This aggregate formation was used as a means to detect M. smegmatis at the concentration of 10(4) CFU per mL.
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Affiliation(s)
- Kalana W Jayawardana
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA 01854, USA.
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32
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Kavitha S, Kaliappan S, Adish Kumar S, Yeom IT, Rajesh Banu J. Effect of NaCl induced floc disruption on biological disintegration of sludge for enhanced biogas production. Bioresour Technol 2015; 192:807-811. [PMID: 26059405 DOI: 10.1016/j.biortech.2015.05.071] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/20/2015] [Accepted: 05/21/2015] [Indexed: 06/04/2023]
Abstract
In the present study, the influence of NaCl mediated bacterial disintegration of waste activated sludge (WAS) was evaluated in terms of disintegration and biodegradability of WAS. Floc disruption was efficient at 0.03 g/g SS of NaCl, promoting the shifts of extracellular proteins and carbohydrates from inner layers to extractable--soluble layers (90 mg/L), respectively. Outcomes of sludge disintegration reveal that the maximum solubilization achieved was found to be 23%, respectively. The model elucidating the parameter evaluation, explicates that floc disrupted--bacterially disintegrated sludge (S3) showed superior biodegradability of about 0.23 (gCOD/gCOD) than the bacterially disintegrated (S2) and control (S3) sludges of about 0.13 (gCOD/gCOD) and 0.05 (gCOD/gCOD), respectively. Cost evaluation of the present study affords net profits of approximately 2.5 USD and -21.5 USD in S3 and S2 sludge.
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Affiliation(s)
- S Kavitha
- Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India
| | - S Kaliappan
- Department of Civil Engineering, Thiagarajar College of Engineering, Thiruparankundram, Madurai, India
| | - S Adish Kumar
- Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India
| | - Ick Tae Yeom
- Department of Civil and Environmental Engineering, Sungkyunkwan University, Seoul, South Korea
| | - J Rajesh Banu
- Department of Civil Engineering, Regional Centre of Anna University, Tirunelveli, India.
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33
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Zhang B, Chen S. Effect of different organic matters on flocculation of Chlorella sorokiniana and optimization of flocculation conditions in swine manure wastewater. Bioresour Technol 2015; 192:774-80. [PMID: 26111631 DOI: 10.1016/j.biortech.2015.06.068] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 06/05/2015] [Accepted: 06/07/2015] [Indexed: 05/13/2023]
Abstract
In this study, flocculation of Chlorella sorokiniana cultivated in swine manure wastewater, BG-11 medium and BG-11 medium supplemented with different organic matters (glucose, urea and tryptone) was investigated. The results demonstrated that the minimum amount of Al(3+) required for complete flocculation in wastewater would increase substantially, and flocculation efficiency became highly sensitive to pH. Tryptone could cause similar extent of inhibition on flocculation as in wastewater. Meanwhile, glucose could increase concentrations of Algogenic Organic Matter (AOM), inhibiting flocculation strongly at higher pH, including flocculation induced by Al(3+) and autoflocculation. However, urea had little effect on flocculation of C. sorokiniana. Moreover, the major factors: dilution times, pH and flocculants dosage, which had significant impact on flocculation efficiency of C. sorokiniana in piggery wastewater, were optimized using response surface methodology (RSM). The optimal flocculation efficiency (100%) was achieved at pH 8.5, 7-folds of dilution and 52.14 mg L(-1) of Al(3+).
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Affiliation(s)
- Bo Zhang
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing 100193, PR China
| | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.
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34
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Bai F, Dong C, Cao C, Sun R. Investigation of cell aggregation on the substrate of a parallel-plate flow chamber. Cell Mol Biol (Noisy-le-grand) 2015; 61:86-93. [PMID: 26025409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 05/18/2015] [Indexed: 06/04/2023]
Abstract
Adhesion of tumor cells (TCs) to polymorphonuclear neutrophils (PMNs) tethered on a monolayer of vascular endothelial cells (ECs) in shear flows is investigated theoretically. Both TC—PMN and PMN—EC aggregations are modeled using the population balance equations (PBEs). Parameters in the model obtained by curve fitting show that an increase of shear rate or viscosity will suppress the formation of aggregates and promote the breakage of them. Analysis on the collision frequency suggests that the averaged encounter duration is affected by viscosity. Based on the model, a nonlinear connection between the number of migrated TCs and the concentration of PMNs in the flow near the substrate is presented.
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Affiliation(s)
- F Bai
- Shanghai Jiao Tong University Department of Engineering Mechanics Shanghai China
| | - C Dong
- The Pennsylvania State University Department of Bioengineering USA
| | - C Cao
- Shanghai Jiao Tong University School of Life Science & Biotechnology Shanghai China
| | - R Sun
- Shanghai Jiao Tong University Department of Engineering Mechanics Shanghai China drrsun@sjtu.edu.cn
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35
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Wu F, Jin J, Wang L, Sun P, Yuan H, Yang Z, Chen G, Fan QH, Liu D. Functionalization of DNA-dendron supramolecular fibers and application in regulation of Escherichia coli association. ACS Appl Mater Interfaces 2015; 7:7351-7356. [PMID: 25782730 DOI: 10.1021/acsami.5b00702] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Specific carbohydrate recognition in biology is a dynamic process. Thus, supramolecular multivalent scaffolds with dynamic features have been applied to mimic this process. Herein, we prepared DNA-dendron supramolecular fibers and synthesized carbohydrate-oligonucleotide conjugates (C18-mannose). Via DNA hybridization, the C18-mannose could be guided onto the fiber platform and form multiple mannose-functionalized fibers, which can be utilized to agglutinate E. coli because of high affinity among multivalent mannose ligands and receptors on E. coli. In addition, via chain exchange reaction of DNAs, the E. coli could be dissociated by replacing multivalent mannose ligands with competitive unmodified DNA sequences. The association and dissociation processes of E. coli are confirmed by fluorescent microscope and transmission electron microscope (TEM). These results not only demonstrate the ability of DNA-dendron fibers in reversibly associating E. coli but also illustrate their potential to be an easily modified multivalent supramolecular platform.
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Affiliation(s)
- Fen Wu
- †Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China
| | | | - Liying Wang
- †Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China
| | - Pengfei Sun
- §The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Huanxiang Yuan
- ∥Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China
| | | | - Guosong Chen
- §The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Qing-Hua Fan
- †Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, China
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36
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Scherer A, Kuhl S, Wessels D, Lusche DF, Hanson B, Ambrose J, Voss E, Fletcher E, Goldman C, Soll DR. A computer-assisted 3D model for analyzing the aggregation of tumorigenic cells reveals specialized behaviors and unique cell types that facilitate aggregate coalescence. PLoS One 2015; 10:e0118628. [PMID: 25790299 PMCID: PMC4366230 DOI: 10.1371/journal.pone.0118628] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 11/28/2014] [Indexed: 01/11/2023] Open
Abstract
We have developed a 4D computer-assisted reconstruction and motion analysis system, J3D-DIAS 4.1, and applied it to the reconstruction and motion analysis of tumorigenic cells in a 3D matrix. The system is unique in that it is fast, high-resolution, acquires optical sections using DIC microscopy (hence there is no associated photoxicity), and is capable of long-term 4D reconstruction. Specifically, a z-series at 5 μm increments can be acquired in less than a minute on tissue samples embedded in a 1.5 mm thick 3D Matrigel matrix. Reconstruction can be repeated at intervals as short as every minute and continued for 30 days or longer. Images are converted to mathematical representations from which quantitative parameters can be derived. Application of this system to cancer cells from established lines and fresh tumor tissue has revealed unique behaviors and cell types not present in non-tumorigenic lines. We report here that cells from tumorigenic lines and tumors undergo rapid coalescence in 3D, mediated by specific cell types that we have named “facilitators” and “probes.” A third cell type, the “dervish”, is capable of rapid movement through the gel and does not adhere to it. These cell types have never before been described. Our data suggest that tumorigenesis in vitro is a developmental process involving coalescence facilitated by specialized cells that culminates in large hollow spheres with complex architecture. The unique effects of select monoclonal antibodies on these processes demonstrate the usefulness of the model for analyzing the mechanisms of anti-cancer drugs.
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Affiliation(s)
- Amanda Scherer
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Spencer Kuhl
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Deborah Wessels
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Daniel F. Lusche
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Brett Hanson
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Joseph Ambrose
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Edward Voss
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
| | - Emily Fletcher
- Mercy Hospital System of Des Moines, Des Moines, Iowa, United States of America
| | - Charles Goldman
- Mercy Hospital System of Des Moines, Des Moines, Iowa, United States of America
| | - David R. Soll
- Monoclonal Antibody Research Institute, Developmental Studies Hybridoma Bank, Department of Biology, University of Iowa, Iowa City, Iowa, 52242, United States of America
- * E-mail:
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37
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Mokhtari Z, Mech F, Zehentmeier S, Hauser AE, Figge MT. Quantitative image analysis of cell colocalization in murine bone marrow. Cytometry A 2015; 87:503-12. [PMID: 25652548 DOI: 10.1002/cyto.a.22641] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/23/2014] [Accepted: 01/14/2015] [Indexed: 01/25/2023]
Abstract
Long-term antibody production is a key property of humoral immunity and is accomplished by long-lived plasma cells. They mainly reside in the bone marrow, whose importance as an organ hosting immunological memory is becoming increasingly evident. Signals provided by stromal cells and eosinophils may play an important role for plasma cell maintenance, constituting a survival microenvironment. In this joint study of experiment and theory, we investigated the spatial colocalization of plasma cells, eosinophils and B cells by applying an image-based systems biology approach. To this end, we generated confocal fluorescence microscopy images of histological sections from murine bone marrow that were subsequently analyzed in an automated fashion. This quantitative analysis was combined with computer simulations of the experimental system for hypothesis testing. In particular, we tested the observed spatial colocalization of cells in the bone marrow against the hypothesis that cells are found within available areas at positions that were drawn from a uniform random number distribution. We find that B cells and plasma cells highly colocalize with stromal cells, to an extent larger than in the simulated random situation. While B cells are preferentially in contact with each other, i.e., form clusters among themselves, plasma cells seem to be solitary or organized in aggregates, i.e., loosely defined groups of cells that are not necessarily in direct contact. Our data suggest that the plasma cell bone marrow survival niche facilitates colocalization of plasma cells with stromal cells and eosinophils, respectively, promoting plasma cell longevity.
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Affiliation(s)
- Zeinab Mokhtari
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz-Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
- Friedrich Schiller University Jena, Germany
| | - Franziska Mech
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz-Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
- Immunodynamics, German Rheumatism Research Centre (DRFZ), Leibniz-Institute, Berlin, Germany
| | - Sandra Zehentmeier
- Immunodynamics, German Rheumatism Research Centre (DRFZ), Leibniz-Institute, Berlin, Germany
| | - Anja E Hauser
- Immunodynamics, German Rheumatism Research Centre (DRFZ), Leibniz-Institute, Berlin, Germany
- Charité University Medicine, Berlin, Germany
| | - Marc Thilo Figge
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz-Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
- Friedrich Schiller University Jena, Germany
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Robu A, Stoicu-Tivadar L, Robu N, Neagu A. Computational study of the self-assembly of two different cell populations in contact with a biomaterial. Stud Health Technol Inform 2015; 210:761-765. [PMID: 25991256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The organisation of a heterotypic multicellular system is intensely studied in developmental biology, tissue engineering and regenerative medicine.To address this problem, we have created a computational model of a biological system made of two cell populations of various cohesivities, and simulated its evolution on the surface of biomaterials of different adhesivities. To this end, it was necessary to extend our SIMMMC application with algorithms that treat two cell types. We have observed, in accordance with experiments that, depending on the strength of cell-substrate adhesion, different structures emerge by the self-assembly of the two cell populations. The agreement with experimental results validates the extended version of the SIMMMC application, suggesting that this tool might offer useful insights for tissue engineers.
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Affiliation(s)
- Andreea Robu
- Department of Automation and Applied Informatics, "Politehnica" University of Timisoara, Timisoara, Romania
| | - Lacramioara Stoicu-Tivadar
- Department of Automation and Applied Informatics, "Politehnica" University of Timisoara, Timisoara, Romania
| | - Nicolae Robu
- Department of Automation and Applied Informatics, "Politehnica" University of Timisoara, Timisoara, Romania
| | - Adrian Neagu
- Center for Modeling Biological Systems and Data Analysis, Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
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Ren YX, Yang L, Liang X. The characteristics of a novel heterotrophic nitrifying and aerobic denitrifying bacterium, Acinetobacter junii YB. Bioresour Technol 2014; 171:1-9. [PMID: 25171329 DOI: 10.1016/j.biortech.2014.08.058] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 08/09/2014] [Accepted: 08/11/2014] [Indexed: 06/03/2023]
Abstract
A novel heterotrophic nitrifying bacterium was isolated from activated sludge and was identified as Acinetobacter junii YB. The strain exhibited efficient heterotrophic nitrification-aerobic denitrification ability at a broad range of ammonium loads and had the capability to utilize hydroxylamine, nitrite and nitrate as a sole nitrogen source. Based on the nitrogen removal and enzyme assay, the nitrogen removal pathway was speculated to be achieved through heterotrophic nitrification coupled with aerobic denitrification. In addition, single-factor experiments showed that efficient heterotrophic nitrification and growth of strain YB occurred with succinate as the carbon source, pH 7.5, 37 °C, and high C/N ratio and dissolved oxygen. Furthermore, the new isolate showed capacities for aggregation and hydrophobicity. Regular variations of the flocculating ability and relative hydrophobicity were observed during the whole cultivation. The ability to perform heterotrophic nitrification-aerobic denitrification and cell aggregation demonstrated the great potential of the strain YB for future applications.
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Affiliation(s)
- Yong-Xiang Ren
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Lei Yang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Xian Liang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
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Wu J, Rostami MR, Cadavid Olaya DP, Tzanakakis ES. Oxygen transport and stem cell aggregation in stirred-suspension bioreactor cultures. PLoS One 2014; 9:e102486. [PMID: 25032842 PMCID: PMC4102498 DOI: 10.1371/journal.pone.0102486] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 06/19/2014] [Indexed: 01/16/2023] Open
Abstract
Stirred-suspension bioreactors are a promising modality for large-scale culture of 3D aggregates of pluripotent stem cells and their progeny. Yet, cells within these clusters experience limitations in the transfer of factors and particularly O2 which is characterized by low solubility in aqueous media. Cultured stem cells under different O2 levels may exhibit significantly different proliferation, viability and differentiation potential. Here, a transient diffusion-reaction model was built encompassing the size distribution and ultrastructural characteristics of embryonic stem cell (ESC) aggregates. The model was coupled to experimental data from bioreactor and static cultures for extracting the effective diffusivity and kinetics of consumption of O2 within mouse (mESC) and human ESC (hESC) clusters. Under agitation, mESC aggregates exhibited a higher maximum consumption rate than hESC aggregates. Moreover, the reaction-diffusion model was integrated with a population balance equation (PBE) for the temporal distribution of ESC clusters changing due to aggregation and cell proliferation. Hypoxia was found to be negligible for ESCs with a smaller radius than 100 µm but became appreciable for aggregates larger than 300 µm. The integrated model not only captured the O2 profile both in the bioreactor bulk and inside ESC aggregates but also led to the calculation of the duration that fractions of cells experience a certain range of O2 concentrations. The approach described in this study can be employed for gaining a deeper understanding of the effects of O2 on the physiology of stem cells organized in 3D structures. Such frameworks can be extended to encompass the spatial and temporal availability of nutrients and differentiation factors and facilitate the design and control of relevant bioprocesses for the production of stem cell therapeutics.
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Affiliation(s)
- Jincheng Wu
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Mahboubeh Rahmati Rostami
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
| | - Diana P. Cadavid Olaya
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Emmanuel S. Tzanakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts, United States of America
- * E-mail:
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Bassagañas S, Carvalho S, Dias AM, Pérez-Garay M, Ortiz MR, Figueras J, Reis CA, Pinho SS, Peracaula R. Pancreatic cancer cell glycosylation regulates cell adhesion and invasion through the modulation of α2β1 integrin and E-cadherin function. PLoS One 2014; 9:e98595. [PMID: 24878505 PMCID: PMC4039506 DOI: 10.1371/journal.pone.0098595] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 05/05/2014] [Indexed: 12/21/2022] Open
Abstract
In our previous studies we have described that ST3Gal III transfected pancreatic adenocarcinoma Capan-1 and MDAPanc-28 cells show increased membrane expression levels of sialyl-Lewis x (SLe(x)) along with a concomitant decrease in α2,6-sialic acid compared to control cells. Here we have addressed the role of this glycosylation pattern in the functional properties of two glycoproteins involved in the processes of cancer cell invasion and migration, α2β1 integrin, the main receptor for type 1 collagen, and E-cadherin, responsible for cell-cell contacts and whose deregulation determines cell invasive capabilities. Our results demonstrate that ST3Gal III transfectants showed reduced cell-cell aggregation and increased invasive capacities. ST3Gal III transfected Capan-1 cells exhibited higher SLe(x) and lower α2,6-sialic acid content on the glycans of their α2β1 integrin molecules. As a consequence, higher phosphorylation of focal adhesion kinase tyrosine 397, which is recognized as one of the first steps of integrin-derived signaling pathways, was observed in these cells upon adhesion to type 1 collagen. This molecular mechanism underlies the increased migration through collagen of these cells. In addition, the pancreatic adenocarcinoma cell lines as well as human pancreatic tumor tissues showed colocalization of SLe(x) and E-cadherin, which was higher in the ST3Gal III transfectants. In conclusion, changes in the sialylation pattern of α2β1 integrin and E-cadherin appear to influence the functional role of these two glycoproteins supporting the role of these glycans as an underlying mechanism regulating pancreatic cancer cell adhesion and invasion.
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Affiliation(s)
- Sònia Bassagañas
- Biochemistry and Molecular Biology Unit, Department of Biology, University of Girona, Girona, Spain
| | - Sandra Carvalho
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Institute of Biomedical Sciences of Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Ana M. Dias
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Institute of Biomedical Sciences of Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Marta Pérez-Garay
- Biochemistry and Molecular Biology Unit, Department of Biology, University of Girona, Girona, Spain
| | - M. Rosa Ortiz
- Department of Pathology, Dr. Josep Trueta University Hospital, Girona, Spain
| | - Joan Figueras
- Department of Surgery, Dr. Josep Trueta University Hospital, IdIBGi, Girona, Spain
| | - Celso A. Reis
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Institute of Biomedical Sciences of Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Medical Faculty, University of Porto, Porto, Portugal
| | - Salomé S. Pinho
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal
- Institute of Biomedical Sciences of Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Rosa Peracaula
- Biochemistry and Molecular Biology Unit, Department of Biology, University of Girona, Girona, Spain
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Sakashita T, Hamada N, Kawaguchi I, Hara T, Kobayashi Y, Saito K. A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts. J Radiat Res 2014; 55:423-431. [PMID: 24501383 PMCID: PMC4014152 DOI: 10.1093/jrr/rrt129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/09/2013] [Accepted: 10/12/2013] [Indexed: 06/03/2023]
Abstract
A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/µm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log-log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE.
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Affiliation(s)
- Tetsuya Sakashita
- Microbeam Radiation Biology Group, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan
| | - Nobuyuki Hamada
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo 201-8511, Japan
| | - Isao Kawaguchi
- Regulatory Science Research Program, Research Center for Radiation Protection, National Institute of Radiological Sciences (NIRS), 4-9-1, Anagawa, Inage, Chiba, 263-8555, Japan
| | - Takamitsu Hara
- Division of Translational Research for Drug Discovery, Fukushima Medical University, 1 Hikarigaoka, Fukushima, Fukushima 960-1295, Japan
| | - Yasuhiko Kobayashi
- Microbeam Radiation Biology Group, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292, Japan
| | - Kimiaki Saito
- Fukushima Environmental Safety Center, JAEA, 2-2-2 Uchisaiwai, Chiyoda, Tokyo 100-0011, Japan
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Guidobaldi A, Jeyaram Y, Berdakin I, Moshchalkov VV, Condat CA, Marconi VI, Giojalas L, Silhanek AV. Geometrical guidance and trapping transition of human sperm cells. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 89:032720. [PMID: 24730887 DOI: 10.1103/physreve.89.032720] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Indexed: 05/14/2023]
Abstract
The guidance of human sperm cells under confinement in quasi-2D microchambers is investigated using a purely physical method to control their distribution. Transport property measurements and simulations are performed with diluted sperm populations, for which effects of geometrical guidance and concentration are studied in detail. In particular, a trapping transition at convex angular wall features is identified and analyzed. We also show that highly efficient microratchets can be fabricated by using curved asymmetric obstacles to take advantage of the spermatozoa specific swimming strategy.
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Affiliation(s)
- A Guidobaldi
- Instituto de Investigaciones Biológicas y Tecnológicas, CONICET and Centro de Biología Celular y Molecular, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000-Córdoba, Argentina
| | - Y Jeyaram
- Institute for Nanoscale Physics and Chemistry, KU Leuven, B-3001 Leuven, Belgium
| | - I Berdakin
- Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG-CONICET, X5000HUA Córdoba, Argentina
| | - V V Moshchalkov
- Institute for Nanoscale Physics and Chemistry, KU Leuven, B-3001 Leuven, Belgium
| | - C A Condat
- Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG-CONICET, X5000HUA Córdoba, Argentina
| | - V I Marconi
- Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba and IFEG-CONICET, X5000HUA Córdoba, Argentina
| | - L Giojalas
- Instituto de Investigaciones Biológicas y Tecnológicas, CONICET and Centro de Biología Celular y Molecular, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000-Córdoba, Argentina
| | - A V Silhanek
- Département de Physique, Université de Liège, B-4000 Sart Tilman, Belgium
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Campàs O, Mammoto T, Hasso S, Sperling RA, O'Connell D, Bischof AG, Maas R, Weitz DA, Mahadevan L, Ingber DE. Quantifying cell-generated mechanical forces within living embryonic tissues. Nat Methods 2014; 11:183-189. [PMID: 24317254 DOI: 10.1038/nmeth.2761.quantifying] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 10/22/2013] [Indexed: 05/26/2023]
Abstract
Cell-generated mechanical forces play a critical role during tissue morphogenesis and organ formation in the embryo. Little is known about how these forces shape embryonic organs, mainly because it has not been possible to measure cellular forces within developing three-dimensional (3D) tissues in vivo. We present a method to quantify cell-generated mechanical stresses exerted locally within living embryonic tissues, using fluorescent, cell-sized oil microdroplets with defined mechanical properties and coated with adhesion receptor ligands. After a droplet is introduced between cells in a tissue, local stresses are determined from droplet shape deformations, measured using fluorescence microscopy and computerized image analysis. Using this method, we quantified the anisotropic stresses generated by mammary epithelial cells cultured within 3D aggregates, and we confirmed that these stresses (3.4 nN μm(-2)) are dependent on myosin II activity and are more than twofold larger than stresses generated by cells of embryonic tooth mesenchyme, either within cultured aggregates or in developing whole mouse mandibles.
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Affiliation(s)
- Otger Campàs
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA. [2] Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA. [3] Vascular Biology Program, Children's Hospital, Boston, Massachusetts, USA. [4] Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA. [5]
| | - Tadanori Mammoto
- Vascular Biology Program, Children's Hospital, Boston, Massachusetts, USA
| | - Sean Hasso
- Vascular Biology Program, Children's Hospital, Boston, Massachusetts, USA
| | - Ralph A Sperling
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Daniel O'Connell
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Ashley G Bischof
- 1] Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA. [2] Vascular Biology Program, Children's Hospital, Boston, Massachusetts, USA
| | - Richard Maas
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - David A Weitz
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA. [2] Department of Physics, Harvard University, Cambridge, Massachusetts, USA
| | - L Mahadevan
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA. [2] Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA. [3] Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA. [4] Department of Physics, Harvard University, Cambridge, Massachusetts, USA
| | - Donald E Ingber
- 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA. [2] Wyss Institute for Biologically Inspired Engineering at Harvard University, Boston, Massachusetts, USA. [3] Vascular Biology Program, Children's Hospital, Boston, Massachusetts, USA. [4] Department of Pathology, Harvard Medical School, Boston, Massachusetts, USA
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Milovanovic P, Zimmermann EA, Hahn M, Djonic D, Püschel K, Djuric M, Amling M, Busse B. Osteocytic canalicular networks: morphological implications for altered mechanosensitivity. ACS Nano 2013; 7:7542-7551. [PMID: 23909715 DOI: 10.1021/nn401360u] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Osteocytes are ramified bone cells distributed throughout the bone matrix within a network of micrometer-scale cavities (lacunae) and numerous nanometer-thick tunnels (canaliculi). The integrity of the canalicular network might influence bone quality and reflect its mechanosensory potential. In this study, we applied an acid etching technique to embedded bone specimens that allows 3D observation of the canalicular network across a 2D plane to quantitatively assess the canalicular connections in cortical bone specimens from young and aged individuals. Our results showed a nearly 30% reduction in the number of canaliculi per osteocyte lacuna in aged individuals (N.Ot.Ca/Ot.Lc: 15.92 ± 1.5 in aged vs 22.10 ± 2.82 in young; p < 0.001); moreover, canalicular number was found to be inversely related to the osteonal tissue age represented by Ca/P ratio (p < 0.001). We frequently observed the phenomenon that canaliculi of osteocytes located near the osteon's periphery did not end at the osteon's cement line boundary but penetrated through the cement line and spread into the surrounding bone matrix, thus establishing an "external rooting" or "connection", which might have significant relevance to bone quality. Our findings showed that not only does the aging process diminish the canalicular network within osteons, but it also significantly reduces the probability of external osteonal rooting and connections with the surrounding bone tissue. Deterioration in the canalicular network with age reduces the connectivity between osteocytes and between osteons/interstitial tissue, which affects the supply of nutrients to osteocytes, degrades their mechanosensitivity, and contributes to increased bone fragility in the elderly.
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Affiliation(s)
- Petar Milovanovic
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf , Lottestraße 59, 22529 Hamburg, Germany
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Fujie T, Ahadian S, Liu H, Chang H, Ostrovidov S, Wu H, Bae H, Nakajima K, Kaji H, Khademhosseini A. Engineered nanomembranes for directing cellular organization toward flexible biodevices. Nano Lett 2013; 13:3185-3192. [PMID: 23758622 DOI: 10.1021/nl401237s] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Controlling the cellular microenvironment can be used to direct the cellular organization, thereby improving the function of synthetic tissues in biosensing, biorobotics, and regenerative medicine. In this study, we were inspired by the microstructure and biological properties of the extracellular matrix to develop freestanding ultrathin polymeric films (referred as "nanomembranes") that were flexible, cell adhesive, and had a morphologically tailorable surface. The resulting nanomembranes were exploited as flexible substrates on which cell-adhesive micropatterns were generated to align C2C12 skeletal myoblasts and embedded fibril carbon nanotubes enhanced the cellular elongation and differentiation. Functional nanomembranes with tunable morphology and mechanical properties hold great promise in studying cell-substrate interactions and in fabricating biomimetic constructs toward flexible biodevices.
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Affiliation(s)
- Toshinori Fujie
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University , 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
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Abstract
Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells' spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness ℓ of the outer shell of cells in the cluster that receives enough nutrient to grow. The cells are treated as partially absorbing identical spherical nutrient sinks, and we identify a dimensionless parameter ν that characterizes the absorption strength of each cell. The parameter ν can vary over many orders of magnitude among different cell types, ranging from bacteria and yeast to human tissue. The thickness ℓ decreases with increasing ν, increasing cell volume fraction φ, and decreasing ambient nutrient concentration ψ(∞). The theoretical results are compared with numerical simulations and experiments. In the latter studies, colonies of budding yeast, Saccharomyces cerevisiae, are grown on glucose media and imaged under a confocal microscope. We measure the growth inside the colonies via a fluorescent protein reporter and compare the experimental and theoretical results for the thickness ℓ.
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Chen K, Xiong H, Huang Y, Liu C. Comparative analysis of in vitro periodontal characteristics of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). Arch Oral Biol 2013; 58:997-1006. [PMID: 23582988 DOI: 10.1016/j.archoralbio.2013.02.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/17/2013] [Accepted: 02/13/2013] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The aim of this study was to compare the in vitro periodontal properties of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). DESIGN SCAP and PDLSCs cultures were established from normal human impacted third molars with immature roots. The cells were cultured in differentiation medium containing dexamethasone, ß-glycerophosphate and ascorbate phosphate for 3 weeks and in normal medium for as long as 60 days, and then were analysed for mineralisation potential. Cell proliferation, colony-forming capacity and periodontal ligament (PDL)-specific markers were also measured. The mineralisation markers, including alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OC), were investigated by immunofluorescence staining and real-time polymerase chain reaction. The expression of PDL markers, including periostin and S100A4, was confirmed by reverse transcription polymerase chain reaction. RESULTS SCAP showed a significantly higher proliferation rate and colony-forming capacity than PDLSCs. Both types of cells displayed mineralisation potential after induction and long-term culture. The SCAP, however, exhibited higher levels of ALP, BSP and OC expression than the PDLSCs. Like the PDLSCs, the SCAP exhibited periostin and S100A4 expression. CONCLUSIONS Our study provides the first evidence showing that SCAP express periodontal properties in vitro. SCAP not only showed PDL-related markers, but also displayed a higher proliferation rate and a greater mineralisation capacity than those of PDLSCs. It might help understand the development of tooth root and periodontium. Furthermore, SCAP could be a promising candidate for periodontal tissue engineering.
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Affiliation(s)
- Ke Chen
- Department of Stomatology, Guangzhou Women and Children's Medical Center, 9 Jinsui Road, Guangzhou 510623, PR China.
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Voegel TM, Doddapaneni H, Cheng DW, Lin H, Stenger DC, Kirkpatrick BC, Roper MC. Identification of a response regulator involved in surface attachment, cell-cell aggregation, exopolysaccharide production and virulence in the plant pathogen Xylella fastidiosa. Mol Plant Pathol 2013; 14:256-264. [PMID: 23186359 PMCID: PMC6638743 DOI: 10.1111/mpp.12004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Xylella fastidiosa, the causal agent of Pierce's disease of grapevine, possesses several two-component signal transduction systems that allow the bacterium to sense and respond to changes in its environment. Signals are perceived by sensor kinases that autophosphorylate and transfer the phosphate to response regulators (RRs), which direct an output response, usually by acting as transcriptional regulators. In the X. fastidiosa genome, 19 RRs were found. A site-directed knockout mutant in one unusual RR, designated XhpT, composed of a receiver domain and a histidine phosphotransferase output domain, was constructed. The resulting mutant strain was analysed for changes in phenotypic traits related to biofilm formation and gene expression using microarray analysis. We found that the xhpT mutant was altered in surface attachment, cell-cell aggregation, exopolysaccharide (EPS) production and virulence in grapevine. In addition, this mutant had an altered transcriptional profile when compared with wild-type X. fastidiosa in genes for several biofilm-related traits, such as EPS production and haemagglutinin adhesins.
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Affiliation(s)
- Tanja M Voegel
- Department of Plant Pathology, University of California, Davis, CA 95616, USA
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50
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Lv Y, Wan C, Liu X, Zhang Y, Lee DJ, Tay JH. Drying and re-cultivation of aerobic granules. Bioresour Technol 2013; 129:700-703. [PMID: 23357589 DOI: 10.1016/j.biortech.2012.12.178] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 12/24/2012] [Accepted: 12/26/2012] [Indexed: 06/01/2023]
Abstract
Aerobic granules stored in liquid medium can lose structural integrity during storage. This study demonstrated that the aerobic granules cultivated by seeding activated sludge into column-type sequential batch reactors and fed with synthetic wastewater at organic loading rate of 1.5 kg/m3-d can be dried by acetone gradient method to moisture content less than 1%. Then, the dried granules can be reactivated through a re-cultivation process to recover their organic degradation capacity in 12 h, or their appearance in 5 d. During the drying and recovery, the granules experienced volume and weight losses by >80% and >85%, respectively, with minimal loss in structural integrity. The microbial communities of the dried and re-cultivated granules were probed using polymerase chain reaction-denaturing gradient gel electrophoresis technique. The family Xanthomonadaceae and the family Comamonas can survive in dried granules and could contribute to maintain structural integrity in re-cultivation stage.
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Affiliation(s)
- Yi Lv
- Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China
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