scholarly journals Evolution of a confluent gut epithelium under cyclic stretching

2021 ◽  
Author(s):  
Lauriane Géremie ◽  
Efe Ilker ◽  
Moencopi Bernheim-Dennery ◽  
Charles Cavaniol ◽  
Jean-Louis Viovy ◽  
...  
Keyword(s):  
Planar Cell Polarity ◽  
Spatial Organization ◽  
Elastic Anisotropy ◽  
Cell Types ◽  
Peristaltic Motion ◽  
Relaxation Dynamics ◽  
Gi Tract ◽  
Cyclic Stretching ◽  
Orientational Response

The progress of food in the gastrointestinal (GI) tract is driven by a peristaltic motion generated by the muscle belt surrounding the GI tract. In turn, the response of the intestinal epithelial cells to the peristaltic stresses affects the dynamics of the epithelial structure. In this work, we study the effect of cyclic stretching (0.125 Hz, 10% strain) on the spatial organization of the intestinal epithelium using intestinal cells deposited on a flat elastomeric substrate to mimic the peristaltic motion in vitro. A confluent monolayer of Caco-2 cells is grown on a PDMS chip to probe the morphological and orientational response of the tissue to cyclic stretching. The PDMS chips are either covalently or non-covalently coated with laminin to recapitulate the basement membrane. We observe a significant orientational response where the cells rearrange their long axes perpendicular to the stretching direction for both coating conditions. The experiment is modeled by a vertex model where the cells store elastic energy with varying strain and effectively have a rotational diffusive motion through rearrangements of their shapes. The model also predicts a transition between the perpendicular orientation and orientation at an oblique angle determined by the level of the cell elastic anisotropy. It provides a general framework to study cell response and relaxation dynamics under cyclic stretching across different cell types. We also discuss potential relevance of peristalsis in determining planar cell polarity in 3D architectures.

scholarly journals Development of a 3D atlas of the embryonic pancreas for topological and quantitative analysis of heterologous cell interactions

2021 ◽  
Author(s):  
Laura Glorieux ◽  
Aleksandra Sapala ◽  
David Willnow ◽  
Manon Moulis ◽  
Shlomit Edri ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Current Knowledge ◽  
Image Data ◽  
Light Sheet ◽  
Cell Types ◽  
Pancreatic Tissue ◽  
Embryonic Cell ◽  
Cell Interactions ◽  
Distinct Cell

AbstractGenerating comprehensive image maps, while preserving spatial 3D context, is essential to quantitatively assess and locate specific cellular features and cell-cell interactions during organ development. Despite the recent advances in 3D imaging approaches, our current knowledge of the spatial organization of distinct cell types in the embryonic pancreatic tissue is still largely based on 2D histological sections. Here, we present a light-sheet fluorescence microscopy approach to image the pancreas in 3D and map tissue interactions at key development time points in the mouse embryo. We used transgenic mouse models and antibodies to visualize the three main cellular components within the developing pancreas, including epithelial, mesenchymal and endothelial cell populations. We demonstrated the utility of the approach by providing volumetric data, 3D distribution of distinct progenitor populations and quantification of relative cellular abundance within the tissue. Lastly, our image data were combined in an open source online repository (referred to as Pancreas Embryonic Cell Atlas). This image dataset will serve the scientific community by enabling further investigation on pancreas organogenesis but also for devising strategies for the in vitro generation of transplantable pancreatic tissue for regenerative therapies.

scholarly journals Small organelle, big responsibility: the role of centrosomes in development and disease

2014 ◽  
Vol 369 (1650) ◽  
pp. 20130468 ◽  
Author(s):  
Pavithra L. Chavali ◽  
Monika Pütz ◽  
Fanni Gergely
Keyword(s):  
Developmental Disorders ◽  
Primary Cilia ◽  
Spatial Organization ◽  
Growth Failure ◽  
Cell Types ◽  
Model Systems ◽  
And Migration ◽  
Division Cell

The centrosome, a key microtubule organizing centre, is composed of centrioles, embedded in a protein-rich matrix. Centrosomes control the internal spatial organization of somatic cells, and as such contribute to cell division, cell polarity and migration. Upon exiting the cell cycle, most cell types in the human body convert their centrioles into basal bodies, which drive the assembly of primary cilia, involved in sensing and signal transduction at the cell surface. Centrosomal genes are targeted by mutations in numerous human developmental disorders, ranging from diseases exclusively affecting brain development, through global growth failure syndromes to diverse pathologies associated with ciliary malfunction. Despite our much-improved understanding of centrosome function in cellular processes, we know remarkably little of its role in the organismal context, especially in mammals. In this review, we examine how centrosome dysfunction impacts on complex physiological processes and speculate on the challenges we face when applying knowledge generated from in vitro and in vivo model systems to human development.

scholarly journals In vitro effects on cellular shaping, contratility, cytoskeletal organization and mitochondrial activity in HL1 cells after different sounds stimulation. A qualitative pilot study and a theoretical physical model

2020 ◽  
Author(s):  
Carlo Dal Lin ◽  
Claudia Maria Radu ◽  
Giuseppe Vitiello ◽  
Paola Romano ◽  
Albino Polcari ◽  
...  
Keyword(s):  
Physical Model ◽  
Spatial Organization ◽  
Time Lapse ◽  
Cell Types ◽  
Convincing Evidence ◽  
Cytoskeletal Proteins ◽  
Mitochondrial Activity ◽  
Sound Waves ◽  
Alpha Tubulin

AbstractConvincing evidence has documented that mechanical vibrations profoundly affect the behaviour of different cell types and even the functions of different organs. Pressure waves such as those of sound could affect cytoskeletal molecules with coherent changes in their spatial organization and are conveyed to cellular nucleus via mechanotransduction. HL1 cells were grown and exposed to different sounds. Subsequently, cells were stained for phalloidin, beta-actin, alpha-tubulin, alpha-actinin-1 and MitoTracker® mitochondrial probe. The cells were analyzed with time-lapse and immunofluorescence/confocal microscopy. In this paper, we describe that different sound stimuli seem to influence the growth or death of HL1 cells, resulting in a different mitochondrial localization and expression of cytoskeletal proteins. Since the cellular behaviour seems to correlate with the meaning of the sound used, we speculate that it can be “understood” by the cells by virtue of the different sound waves geometric properties that we have photographed and filmed. A theoretical physical model is proposed to explain our preliminary results.

scholarly journals Stromal cells regulate malignant B-cell spatial organization, survival, and drug response in a new 3D model mimicking lymphoma tumor niche

2020 ◽  
Author(s):  
Claire Lamaison ◽  
Simon Latour ◽  
Nelson Hélaine ◽  
Valérie Le Morvan ◽  
Céline Monvoisin ◽  
...  
Keyword(s):  
B Cell ◽  
Stromal Cells ◽  
Drug Response ◽  
Spatial Organization ◽  
3D Model ◽  
Cell Types ◽  
Self Organized ◽  
Biomechanical Forces ◽  
3D Spheroids

ABSTRACTNon-Hodgkin B-cell lymphomas (B-NHL) mainly develop within lymph nodes as densely packed aggregates of tumor cells and their surrounding microenvironment, creating a tumor niche specific to each lymphoma subtypes. Until now, in vitro preclinical models mimicking biomechanical forces, cellular microenvironment, and 3D organization of B lymphomas remain scarce while all these parameters constitute key determinants of lymphomagenesis and drug resistance. Using a microfluidic method based on the encapsulation of cells inside permeable, elastic, and hollow alginate microspheres, we developed a new tunable 3D-model incorporating extracellular matrix and/or stromal cells. Lymphoma B cells and stromal cells dynamically formed self-organized 3D spheroids, thus initiating a coevolution of these two cell types, reflecting their bidirectional crosstalk, and recapitulating the heterogeneity of B-NHL subtypes. In addition, this approach makes it suitable to assess in a relevant in vitro model the activity of new therapeutic agents in B-NHL.

scholarly journals 3D in vitro models of skeletal muscle: myopshere, myobundle and bioprinted muscle construct

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Frederic Dessauge ◽  
Cindy Schleder ◽  
Marie-Hélène Perruchot ◽  
Karl Rouger
Keyword(s):  
Skeletal Muscle ◽  
Spatial Organization ◽  
3D Culture ◽  
Cell Types ◽  
In Vitro Models ◽  
Skeletal Muscle Function ◽  
Muscle Tissues ◽  
Culture Models ◽  
Living Tissues

AbstractTypical two-dimensional (2D) culture models of skeletal muscle-derived cells cannot fully recapitulate the organization and function of living muscle tissues, restricting their usefulness in in-depth physiological studies. The development of functional 3D culture models offers a major opportunity to mimic the living tissues and to model muscle diseases. In this respect, this new type of in vitro model significantly increases our understanding of the involvement of the different cell types present in the formation of skeletal muscle and their interactions, as well as the modalities of response of a pathological muscle to new therapies. This second point could lead to the identification of effective treatments. Here, we report the significant progresses that have been made the last years to engineer muscle tissue-like structures, providing useful tools to investigate the behavior of resident cells. Specifically, we interest in the development of myopshere- and myobundle-based systems as well as the bioprinting constructs. The electrical/mechanical stimulation protocols and the co-culture systems developed to improve tissue maturation process and functionalities are presented. The formation of these biomimetic engineered muscle tissues represents a new platform to study skeletal muscle function and spatial organization in large number of physiological and pathological contexts.

scholarly journals Actuation enhances patterning in human neural tube organoids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Abdel Rahman Abdel Fattah ◽  
Brian Daza ◽  
Gregorius Rustandi ◽  
Miguel Ángel Berrocal-Rubio ◽  
Benjamin Gorissen ◽  
...  
Keyword(s):  
Neural Tube ◽  
Regulatory Networks ◽  
Planar Cell Polarity ◽  
Spatial Organization ◽  
Cell Communication ◽  
Mechanical Forces ◽  
Matrix Stiffness ◽  
Physical Interactions ◽  
Gene Regulatory

AbstractTissues achieve their complex spatial organization through an interplay between gene regulatory networks, cell-cell communication, and physical interactions mediated by mechanical forces. Current strategies to generate in-vitro tissues have largely failed to implement such active, dynamically coordinated mechanical manipulations, relying instead on extracellular matrices which respond to, rather than impose mechanical forces. Here, we develop devices that enable the actuation of organoids. We show that active mechanical forces increase growth and lead to enhanced patterning in an organoid model of the neural tube derived from single human pluripotent stem cells (hPSC). Using a combination of single-cell transcriptomics and immunohistochemistry, we demonstrate that organoid mechanoregulation due to actuation operates in a temporally restricted competence window, and that organoid response to stretch is mediated extracellularly by matrix stiffness and intracellularly by cytoskeleton contractility and planar cell polarity. Exerting active mechanical forces on organoids using the approaches developed here is widely applicable and should enable the generation of more reproducible, programmable organoid shape, identity and patterns, opening avenues for the use of these tools in regenerative medicine and disease modelling applications.

scholarly journals Single-cell trajectory inference guided enhancement of thyroid maturation in vitro using TGF-beta inhibition

2021 ◽  
Author(s):  
Mírian Romitti ◽  
Sema Elif Eski ◽  
Barbara Faria Fonseca ◽  
Sumeet Pal Singh ◽  
Sabine Costagliola
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Planar Cell Polarity ◽  
Embryonic Stem ◽  
Cell Types ◽  
Functional Improvement ◽  
Tgf Beta ◽  
Maturation In Vitro ◽  
Cell Trajectory

AbstractThe thyroid gland regulates metabolism and growth via secretion of thyroid hormones by thyroid follicular cells (TFCs). Loss of TFCs, by cellular dysfunction, autoimmune destruction or surgical resection, underlies hypothyroidism. Recovery of thyroid hormone levels by transplantation of mature TFCs derived from stem cells in vitro holds great therapeutic promise. However, the utilization of in vitro derived tissue for regenerative medicine is restricted by the efficiency of differentiation protocols to generate mature organoids. Here, to improve the differentiation efficiency for thyroid organoids, we utilized single-cell RNA-Seq to chart the molecular steps undertaken by individual cells during the in vitro transformation of mouse embryonic stem cells to TFCs. Our single-cell atlas of mouse organoid systematically and comprehensively identifies, for the first time, the cell types generated during production of thyroid organoids. Using pseudotime analysis, we identify TGF-beta and planar-cell polarity (PCP) pathways as regulators of thyroid maturation in vitro. Using pharmacological manipulation of TGF-beta pathway, we improve the level of thyroid maturation, in particular the induction of Nis expression. This in turn, leads to an enhancement of iodide organification in vitro, suggesting functional improvement of the thyroid organoid. Our study highlights the potential of single-cell molecular characterization in understanding and improving thyroid maturation and paves the way for identification of therapeutic targets against thyroid disorders.

scholarly journals Actuation Enhances Patterning in Human Neural Tube Organoids

2020 ◽  
Author(s):  
Abdel Rahman Abdel Fattah ◽  
Brian Daza ◽  
Gregorius Rustandi ◽  
Miguel Angel Berrocal-Rubio ◽  
Benjamin Gorissen ◽  
...  
Keyword(s):  
Neural Tube ◽  
Regulatory Networks ◽  
Planar Cell Polarity ◽  
Spatial Organization ◽  
Cell Communication ◽  
Mechanical Forces ◽  
Matrix Stiffness ◽  
Physical Interactions ◽  
Gene Regulatory

AbstractTissues achieve their complex spatial organization through an interplay between gene regulatory networks, cell-cell communication, and physical interactions mediated by mechanical forces. Current strategies to generate in-vitro tissues have largely failed to implement such active, dynamically coordinated mechanical manipulations, relying instead on extracellular matrices which respond to, rather than impose mechanical forces. Here we develop devices that enable the actuation of organoids. We show that active mechanical forces increase growth and lead to enhanced patterning in an organoid model of the neural tube derived from single human pluripotent stem cells (hPSC). Using a combination of single-cell transcriptomics and immunohistochemistry, we demonstrate that organoid mechanoregulation due to actuation operates in a temporally restricted competence window, and that organoid response to stretch is mediated extracellularly by matrix stiffness and intracellularly by cytoskeleton contractility and planar cell polarity. Exerting active mechanical forces on organoids using the approaches developed here is widely applicable and should enable the generation of more reproducible, programmable organoid shape, identity and patterns, opening avenues for the use of these tools in regenerative medicine and disease modelling applications.

scholarly journals Recapitulating complex biological signaling environments using a multiplexed, DNA-patterning approach

2020 ◽  
Vol 6 (12) ◽  
pp. eaay5696 ◽  
Author(s):  
Olivia J. Scheideler ◽  
Chun Yang ◽  
Molly Kozminsky ◽  
Kira I. Mosher ◽  
Roberto Falcón-Banchs ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Solid Phase ◽  
Cell Types ◽  
Spatial Patterning ◽  
Presentation Of Self ◽  
Dna Oligonucleotides ◽  
High Throughput Method ◽  
Multiple Cell ◽  
Spatial Presentation

Elucidating how the spatial organization of extrinsic signals modulates cell behavior and drives biological processes remains largely unexplored because of challenges in controlling spatial patterning of multiple microenvironmental cues in vitro. Here, we describe a high-throughput method that directs simultaneous assembly of multiple cell types and solid-phase ligands across length scales within minutes. Our method involves lithographically defining hierarchical patterns of unique DNA oligonucleotides to which complementary strands, attached to cells and ligands-of-interest, hybridize. Highlighting our method’s power, we investigated how the spatial presentation of self-renewal ligand fibroblast growth factor-2 (FGF-2) and differentiation signal ephrin-B2 instruct single adult neural stem cell (NSC) fate. We found that NSCs have a strong spatial bias toward FGF-2 and identified an unexpected subpopulation exhibiting high neuronal differentiation despite spatially occupying patterned FGF-2 regions. Overall, our broadly applicable, DNA-directed approach enables mechanistic insight into how tissues encode regulatory information through the spatial presentation of heterogeneous signals.

scholarly journals Multivalent peptide ligands to probe the chromocenter microenvironment in living cells

2021 ◽  
Author(s):  
Nora Guidotti ◽  
Ádám Eördögh ◽  
Maxime Mivelaz ◽  
Pablo Rivera-Fuentes ◽  
Beat Fierz
Keyword(s):  
Single Molecule ◽  
Spatial Organization ◽  
Interaction Network ◽  
Cell Types ◽  
Underlying Mechanism ◽  
Exact Nature ◽  
Heterochromatin Protein 1 ◽  
Fluorescent Peptide ◽  
Peptide Probes

Chromatin is spatially organized into functional states that are defined by both the presence of specific histone post-translational modifications (PTMs) and a defined set of chromatin-associated "reader" proteins. Different models for the underlying mechanism of such compartmentalization have been proposed, including liquid-liquid phase separation (LLPS) of chromatin-associated proteins to drive spatial organization. Heterochromatin, characterized by lysine 9 methylation on histone H3 (H3K9me3) and the presence of heterochromatin protein 1 (HP1) as a multivalent reader, represents a prime example of a spatially defined chromatin state. Heterochromatin foci exhibit features of protein condensates driven by LLPS; however, the exact nature of the physicochemical environment within heterochromatin in different cell types is not completely understood. Here, we present tools to interrogate the environment of chromatin sub-compartments in the form of modular, cell-permeable, multivalent and fluorescent peptide probes. These probes can be tuned to target specific chromatin states by providing binding sites to reader proteins and can thereby integrate into the PTM-reader interaction network. As a target, here we generate probes specific to HP1, directing them to heterochromatin at chromocenters in mouse fibroblasts. Moreover, we use a polarity-sensing photoactivatable probe that photoconverts to a fluorescent state in phase-separated protein droplets and thereby reports on the local microenvironment. Equipped with this dye, our probes indeed turn fluorescent in murine chromocenters. However, image analysis and single-molecule tracking experiments reveal that the compartments are less dense and more dynamic than HP1 condensates obtained in vitro. Our results thus demonstrate that the local organization of heterochromatin in chromocenters is internally more complex than an HP1 condensate.

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