scholarly journals In silico mechanobiochemical modeling of morphogenesis in cell monolayers

2017 ◽  
Author(s):  
Bahador Marzban ◽  
Xiao Ma ◽  
Xiaoliang Qing ◽  
Hongyan Yuan
Keyword(s):  
Computational Model ◽  
Reaction Diffusion ◽  
Cell Interaction ◽  
Cell Polarization ◽  
Cell Morphogenesis ◽  
Cell Monolayers ◽  
Irregular Shapes ◽  
Cell Substrate ◽  
Living Tissues

Cell morphogenesis is a fundamental process involved in tissue formation. One of the challenges in the fabrication of living tissues in vitro is to recapitulate the complex morphologies of individual cells. Despite tremendous progress in understanding biophysical principles underlying tissue/organ morphogenesis at the organ level, little work has been done to understand morphogenesis at the cellular and microtissue level. In this work, we developed a 2D computational model for studying cell morphogenesis in monolayer tissues. The model is mainly composed of four modules: mechanics of cytoskeleton, cell motility, cell-substrate interaction, and cell-cell interaction. The model integrates the biochemical and mechanical activities within individual cells spatiotemporally. Finite element method (FEM) is used to model the irregular shapes of cells and to solve the resulting system of reaction-diffusion-stress equations. Automated mesh generation is used to handle the element distortion in FEM due to the large shape changes of the cells. The computer program can simulate tens to hundreds of cells interacting with each other and with the elastic substrate on desktop workstations efficiently. The simulations demonstrated that our computational model can be used to study cell polarization, single cell migration, durotaxis, and morphogenesis in cell monolayers.

Effects of fractal surface on C6 glioma cell morphogenesis and differentiation in vitro

Biomaterials ◽  
2010 ◽  
Vol 31 (24) ◽  
pp. 6201-6206 ◽  
Author(s):  
Ping Wang ◽  
Lei Li ◽  
Cheng Zhang ◽  
Qunfang Lei ◽  
Wenjun Fang
Keyword(s):  
Glioma Cell ◽  
C6 Glioma ◽  
Cell Morphogenesis ◽  
Fractal Surface ◽  
C6 Glioma Cell

In vitro maturation of canine oocytes co-cultured with bovine and canine granulosa cell monolayers

2012 ◽  
Vol 77 (2) ◽  
pp. 347-355 ◽  
Author(s):  
Mohammed Ali Abdel-Ghani ◽  
Takashi Shimizu ◽  
Tomoyoshi Asano ◽  
Hiroshi Suzuki
Keyword(s):  
Granulosa Cell ◽  
In Vitro Maturation ◽  
Cell Monolayers

scholarly journals Survival and Proliferation under Severely Hypoxic Microenvironments Using Cell-Laden Oxygenating Hydrogels

2021 ◽  
Vol 12 (2) ◽  
pp. 30
Author(s):  
Shabir Hassan ◽  
Berivan Cecen ◽  
Ramon Peña-Garcia ◽  
Fernanda Roberta Marciano ◽  
Amir K. Miri ◽  
...  
Keyword(s):  
Prolonged Release ◽  
Therapeutic Approaches ◽  
Encapsulated Cells ◽  
Hypoxic Conditions ◽  
Skeletal Myoblasts ◽  
Artificial Tissue ◽  
Delivery Platform ◽  
Living Tissues

Different strategies have been employed to provide adequate nutrients for engineered living tissues. These have mainly revolved around providing oxygen to alleviate the effects of chronic hypoxia or anoxia that result in necrosis or weak neovascularization, leading to failure of artificial tissue implants and hence poor clinical outcome. While different biomaterials have been used as oxygen generators for in vitro as well as in vivo applications, certain problems have hampered their wide application. Among these are the generation and the rate at which oxygen is produced together with the production of the reaction intermediates in the form of reactive oxygen species (ROS). Both these factors can be detrimental for cell survival and can severely affect the outcome of such studies. Here we present calcium peroxide (CPO) encapsulated in polycaprolactone as oxygen releasing microparticles (OMPs). While CPO releases oxygen upon hydrolysis, PCL encapsulation ensures that hydrolysis takes place slowly, thereby sustaining prolonged release of oxygen without the stress the bulk release can endow on the encapsulated cells. We used gelatin methacryloyl (GelMA) hydrogels containing these OMPs to stimulate survival and proliferation of encapsulated skeletal myoblasts and optimized the OMP concentration for sustained oxygen delivery over more than a week. The oxygen releasing and delivery platform described in this study opens up opportunities for cell-based therapeutic approaches to treat diseases resulting from ischemic conditions and enhance survival of implants under severe hypoxic conditions for successful clinical translation.

scholarly journals PenA, a penicillin-binding protein-type thioesterase specialized for small peptide cyclization

2021 ◽  
Author(s):  
Kenichi Matsuda ◽  
Kei Fujita ◽  
Toshiyuki Wakimoto
Keyword(s):  
Enzymatic Activity ◽  
Computational Model ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Small Peptide ◽  
Peptide Cyclization ◽  
Chain Lengths ◽  
Non Ribosomal Peptides

Abstract Penicillin binding protein-type thioesterases (PBP-type TEs) are a recently identified group of peptide cyclases that catalyze head-to-tail macrolactamization of non-ribosomal peptides. PenA, a new member of this group, is involved in the biosyntheses of cyclic pentapeptides. In this study, we demonstrated the enzymatic activity of PenA in vitro, and analyzed its substrate scope with a series of synthetic substrates. A comparison of the reaction profiles between PenA and SurE, a representative PBP-type TE, showed that PenA is more specialized for small peptide cyclization. A computational model provided a possible structural rationale for the altered specificity for substrate chain lengths.

scholarly journals In-vitro study of Limosilactobacillus fermentum PCC adhesion to and integrity of the Caco-2 cell monolayers as affected by pectins

2021 ◽  
Vol 79 ◽  
pp. 104395
Author(s):  
Thanyaporn Srimahaeak ◽  
Fernanda Bianchi ◽  
Ondrej Chlumsky ◽  
Nadja Larsen ◽  
Lene Jespersen
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Cell Monolayers

scholarly journals ATRT-14. MACROPHAGE-TUMOR CELL INTERACTION PROMOTES ATRT PROGRESSION AND CHEMORESISTANCE

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii278-iii278
Author(s):  
Viktoria Melcher ◽  
Monika Graf ◽  
Marta Interlandi ◽  
Natalia Moreno ◽  
Flavia W de Faria ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Chemotherapy Resistance ◽  
Cell Communication ◽  
Xenograft Model ◽  
Cell Interaction ◽  
Immunofluorescent Staining ◽  
Genetic Traits ◽  
Rhabdoid Tumors

Abstract Atypical teratoid/rhabdoid tumors (ATRT) are pediatric brain neoplasms that are known for their heterogeneity concerning pathophysiology and outcome. The three genetically rather uniform but epigenetically distinct molecular subgroups of ATRT alone do not sufficiently explain the clinical heterogeneity. Therefore, we examined the tumor microenvironment (TME) in the context of tumor diversity. By using multiplex-immunofluorescent staining and single-cell RNA sequencing (scRNA-seq) we unveiled the pan-macrophage marker CD68 as a subgroup-independent negative prognostic marker for survival of ATRT patients. ScRNA-seq analysis of murine ATRT-SHH, ATRT-MYC and extracranial RT (eRT) provide a delineation of the TME, which is predominantly infiltrated by myeloid cells: more specifically a microglia-enriched niche in ATRT-SHH and a bone marrow-derived macrophage infiltration in ATRT-MYC and eRT. Exploring the cell-cell communication of tumor cells with tumor-associated immune cells, we found that Cd68+ tumor-associated macrophages (TAMs) are central to intercellular communication with tumor cells. Moreover, we uncovered distinct tumor phenotypes in murine ATRT-MYC that share genetic traits with TAMs. These intermediary cells considerably increase the intratumoral heterogeneity of ATRT-MYC tumors. In vitro co-culture experiments recapitulated the capability of ATRT-MYC cells to interchange cell material with macrophages extensively, in contrast to ATRT-SHH cells. We found that microglia are less involved in the exchange of information with ATRT cells and that direct contact is a prerequisite for incorporation. A relapse xenograft model implied that intermediary cells are involved in the acquisition of chemotherapy resistance. We show evidence that TAM-tumor cell interaction is one mechanism of chemotherapy resistance and relapse in ATRT.

scholarly journals Bacillus cereus Induces Permeability of an In Vitro Blood-Retina Barrier

2008 ◽  
Vol 76 (4) ◽  
pp. 1358-1367 ◽  
Author(s):  
A. L. Moyer ◽  
R. T. Ramadan ◽  
J. Thurman ◽  
A. Burroughs ◽  
M. C. Callegan
Keyword(s):  
Quorum Sensing ◽  
Bacillus Cereus ◽  
Barrier Function ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Toxin Production ◽  
Global Regulator ◽  
Barrier Permeability ◽  
Cell Monolayers

ABSTRACT Most Bacillus cereus toxin production is controlled by the quorum-sensing-dependent, pleiotropic global regulator plcR, which contributes to the organism's virulence in the eye. The purpose of this study was to analyze the effects of B. cereus infection and plcR-regulated toxins on the barrier function of retinal pigment epithelium (RPE) cells, the primary cells of the blood-retina barrier. Human ARPE-19 cells were apically inoculated with wild-type or quorum-sensing-deficient B. cereus, and cytotoxicity was analyzed. plcR-regulated toxins were not required for B. cereus-induced RPE cytotoxicity, but these toxins did increase the rate of cell death, primarily by necrosis. B. cereus infection of polarized RPE cell monolayers resulted in increased barrier permeability, independent of plcR-regulated toxins. Loss of both occludin and ZO-1 expression occurred by 8 h postinfection, but alterations in tight junctions appeared to precede cytotoxicity. Of the several proinflammatory cytokines analyzed, only interleukin-6 was produced in response to B. cereus infection. These results demonstrate the deleterious effects of B. cereus infection on RPE barrier function and suggest that plcR-regulated toxins may not contribute significantly to RPE barrier permeability during infection.

scholarly journals Specific elimination of cytotoxic effector cells. I. Adsorptive behavior of effectors and their precursors and spleen cell monolayers.

1976 ◽  
Vol 144 (4) ◽  
pp. 996-1008 ◽  
Author(s):  
J R Neefe ◽  
D H Sachs
Keyword(s):  
Mouse Spleen ◽  
Spleen Cells ◽  
Effector Cells ◽  
Cell Monolayers ◽  
Specific Suppression ◽  
Normal Spleen ◽  
Adsorptive Behavior ◽  
Cytotoxic Effector ◽  
Primed Mouse

Monolayers formed of normal mouse spleen cells attached to polystyrene coated with poly-L-lysine were tested for their ability to bind specifically antigen-reactive cells in normal or primed mouse spleen. 88 to greater than 98% of the activity of cytotoxic populations was removed by a single adsorption. However, normal spleen cells or spleen cells previously primed in vitro could not be depleted of their capacity to be sensitized, even when adsorption effectively removed all residual cytotoxic activity from the same previously primed population. In fact, exposure to an immunoadsorbent augmented the ultimate cytotoxicity generated in a nonspecific fashion. This augmentation was especially dramatic in the case of a previously primed population and may have reflected the removal of a nonspecific suppressor. If antigen-reactive precursors cannot be removed efficiently by adsorption, other approaches to the generation of tolerant lymphoid populations, such as specific suppression of precursor differentiation must be sought.

scholarly journals SUMOylation Negatively Regulates Angiogenesis by Targeting Endothelial NOTCH Signaling

2017 ◽  
Vol 121 (6) ◽  
pp. 636-649 ◽  
Author(s):  
Xiaolong Zhu ◽  
Sha Ding ◽  
Cong Qiu ◽  
Yanna Shi ◽  
Lin Song ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Developmental Disorders ◽  
Interaction Mechanism ◽  
Growth Factor Receptor ◽  
Vascular Diseases ◽  
Cell Interaction ◽  
Protein Signaling

Rationale: The highly conserved NOTCH (neurogenic locus notch homolog protein) signaling pathway functions as a key cell–cell interaction mechanism controlling cell fate and tissue patterning, whereas its dysregulation is implicated in a variety of developmental disorders and cancers. The pivotal role of endothelial NOTCH in regulation of angiogenesis is widely appreciated; however, little is known about what controls its signal transduction. Our previous study indicated the potential role of post-translational SUMO (small ubiquitin-like modifier) modification (SUMOylation) in vascular disorders. Objective: The aim of this study was to investigate the role of SUMOylation in endothelial NOTCH signaling and angiogenesis. Methods and Results: Endothelial SENP1 (sentrin-specific protease 1) deletion, in newly generated endothelial SENP1 (the major protease of the SUMO system)–deficient mice, significantly delayed retinal vascularization by maintaining prolonged NOTCH1 signaling, as confirmed in cultured endothelial cells. An in vitro SUMOylation assay and immunoprecipitation revealed that when SENP1 associated with N1ICD (NOTCH1 intracellular domain), it functions as a deSUMOylase of N1ICD SUMOylation on conserved lysines. Immunoblot and immunoprecipitation analyses and dual-luciferase assays of natural and SUMO-conjugated/nonconjugated NOTCH1 forms demonstrated that SUMO conjugation facilitated NOTCH1 cleavage. This released N1ICD from the membrane and stabilized it for translocation to the nucleus where it functions as a cotranscriptional factor. Functionally, SENP1-mediated NOTCH1 deSUMOylation was required for NOTCH signal activation in response to DLL4 (Delta-like 4) stimulation. This in turn suppressed VEGF (vascular endothelial growth factor) receptor signaling and angiogenesis, as evidenced by immunoblotted signaling molecules and in vitro angiogenesis assays. Conclusions: These results establish reversible NOTCH1 SUMOylation as a regulatory mechanism in coordinating endothelial angiogenic signaling; SENP1 acts as a critical intrinsic mediator of this process. These findings may apply to NOTCH-regulated biological events in nonvascular tissues and provide a novel therapeutic strategy for vascular diseases and tumors.

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