scholarly journals Contraction and organization of collagen gels by cells cultured from periodontal ligament, gingiva and bone suggest functional differences between cell types

1981 ◽  
Vol 50 (1) ◽  
pp. 299-314
Author(s):  
C.G. Bellows ◽  
A.H. Melcher ◽  
J.E. Aubin
Keyword(s):  
Periodontal Ligament ◽  
Cell Types ◽  
The Other ◽  
Collagen Gels ◽  
Collagen Fibres ◽  
Periodontal Ligament Fibroblasts ◽  
3 Dimensional ◽  
Cell Processes

Monkey periodontal ligament fibroblasts (MPLF cells), human gingival fibroblasts (HGF cells), rat embryonic calvaria cells (REC cells), porcine periodontal ligament epithelial cells (PPLE cells) and rat osteosarcoma 17/2 cells (ROS cells) were incorporated into 3-dimensional collagen gels plated in 60 mm Petri dishes in order: first, to measure the capacity of these cell types to contract; second, to investigate cell-collagen and intercellular relationships during contraction; and third, to define the cellular contribution to tissue contraction in an in vitro system. Measurements at times up to 72 h on 3 ml gels containing 5 × 10(5) cells and with a collagen concentration of 1.20 mg/ml showed that MPLF cells contracted the gels at a significantly greater rate (P less than 0.001) than did the other cell types. In addition, contraction started sooner and was of greater extent than with the other cells. HGF cells contracted the gels more rapidly than REC and PPLE cells, while ROS cells caused no contraction. Several stages of gel compaction could be defined: (1) the attachment of cells to collagen; (2) cellular spreading within the collagen fibre matrix; (3) organization and alignment of collagen fibres by cell processes; (4) cell migration; (5) establishment of intercellular contacts; and (6) the development of a cellular reticular arrangement within the gel and the extension of this arrangement into a 3-dimensional, tissue-like, honeycomb network. Electron microscopic observations on 0.1 ml gels containing MPLF cells showed that, in the early contractile phase, numerous cell processes attached to or enclosed collagen fibrils. These processes contained microfilamentous material and few organelles. In compacted gels, the cells contained an increased amount of distended rough endoplasmic reticulum and Golgi membranes. Since MPLF cells have the capacity for vigorous contraction of the collagen gels and since they develop a reticular, 3-dimensional structure in compacted gels that is reminiscent of the relationship of periodontal ligament fibroblasts to collagen fibres in vivo, it is suggested that they could provide the major force necessary for tooth eruption in vivo. This system also provides a well-defined in vitro model to study the sequential stages that occur during contraction processes.

Association between tension and orientation of periodontal ligament fibroblasts and exogenous collagen fibres in collagen gels in vitro

1982 ◽  
Vol 58 (1) ◽  
pp. 125-138
Author(s):  
C.G. Bellows ◽  
A.H. Melcher ◽  
J.E. Aubin
Keyword(s):  
Three Dimensional ◽  
Lower Surface ◽  
Cytochalasin D ◽  
Collagen Gels ◽  
Collagen Fibres ◽  
Periodontal Ligament Fibroblasts ◽  
The Relationship ◽  
Develop Tension

The relationship between the development of tension in sheets of fibroblasts and the orientation of these cells and collagen fibres in collagen gels was examined. Cell-containing, three-dimensional collagen gels were established in agarose-coated Epon dies measuring 10 mm X 4 mm X 4 mm, to which pieces of demineralized tooth and bone had been attached at opposite ends. Contraction of the gel into an opaque structure suspended between the two particles occurred over 24 h and resulted in concave upper and lateral surfaces and a flat to slightly concave lower surface. Initial orientation of the fibres along the tooth-bone axis was followed by similar orientation of the cells. Gels cast without cells exhibited no change in dimensions. Release of the tooth particle after 12 or 24 h of incubation led to shortening of the contracted gels 5 min following release. This shortening was significantly greater (P less than 0.001) than that of uncontracted or slightly contracted gels (1 h and 3 h incubation). Gels attached at one end only compacted around the site of attachment but did not show orientation of cells or fibres. Gels containing colcemid or cytochalasin D were only slightly compacted and did not develop tension. Collagen fibres, but not cell in colcemid-containing gels, showed some alignment; neither were aligned in the presence of cytochalasin D. These data suggest that both microtubules and microfilaments are necessary for alignment of cells and the establishment of tension between two points of attachment in collagen gels. Furthermore, they lend support to our previously advanced hypothesis that the development of tension between two points can result in the orientation of the cells along an axis connecting the points of attachment. This could provide a mechanism for the development of oriented fibre systems in vivo.

Expression of UNCL during development of periodontal tissue and response of periodontal ligament fibroblasts to mechanical stress in vivo and in vitro

2006 ◽  
Vol 327 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Heung-Joong Kim ◽  
Yong Seok Choi ◽  
Moon-Jin Jeong ◽  
Byung-Ock Kim ◽  
Sung-Hoon Lim ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Periodontal Ligament ◽  
Periodontal Tissue ◽  
Periodontal Ligament Fibroblasts

Gene Profiling in Human Periodontal Ligament Fibroblasts by Subtractive Hybridization

2003 ◽  
Vol 82 (8) ◽  
pp. 641-645 ◽  
Author(s):  
T. Yamamoto ◽  
F. Myokai ◽  
F. Nishimura ◽  
T. Ohira ◽  
N. Shiomi ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Periodontal Ligament ◽  
Subtractive Hybridization ◽  
Gene Profiling ◽  
Human Gingival Fibroblast ◽  
Gingival Fibroblast ◽  
Periodontal Ligament Fibroblasts ◽  
Human Periodontal Ligament Fibroblasts

Genes expressed by human periodontal ligament fibroblasts (HPFs) are likely to be associated with specific functions of the ligament. The aim of this study is to profile genes expressed highly by HPFs. A library (6 × 103 pfu) was constructed, followed by subtraction of HPF cDNAs with human gingival fibroblast (HGF) cDNAs. Reverse-dot hybridization revealed that 33 clones expressed higher levels of specific mRNAs in HPFs than in HGFs. These were mRNAs for known genes, including several associated with maturation and differentiation of cells. None had been reported in PFs. One clone, PDL-29, identified as a COX assembly factor, showed much stronger mRNA expression in HPFs than in HGFs in culture. In rat periodontium, however, PDL-29 mRNA expression was similar in PFs and GFs. These results suggest that HPFs express many previously unreported genes associated with maturation and differentiation, but expression can differ in vitro and in vivo.

Carboxyfluorescein Diacetate Succinimidyl Ester Facilitates Cell Tracing and Colocalization Studies in Bioartificial Organ Engineering

2003 ◽  
Vol 26 (3) ◽  
pp. 235-240 ◽  
Author(s):  
K. Mueller-Stahl ◽  
T. Kofidis ◽  
P. Akhyari ◽  
B. Wachsmann ◽  
A. Lenz ◽  
...  
Keyword(s):  
Collagen Matrix ◽  
Cell Types ◽  
Neonatal Rat ◽  
Myocardial Tissue ◽  
Rat Cardiomyocytes ◽  
Organ Engineering ◽  
3 Dimensional ◽  
High Yields

Background We demonstrate a method that includes colocalization studies to analyze cell suspensions after isolation and to characterize 3-dimensional grafts consisting of cells and matrix in vitro and in vivo. Materials and methods Neonatal rat cardiomyocytes were labelled by CFDA-SE after harvest. Cells in the isolated cell suspension, the embodied cells in the seeded scaffolds were characterized measuring features such as viability and distribution of the cell types. Results Selective cell count revealed high yields of viable cardiomyocytes. After seeding cells in collagen matrix, viability of the cells decreased gradually in the time process in vitro. Histology of implanted bioartificial myocardial tissue detected viable cardiomyocytes within the graft. Conclusion Using colocalization histology we could label and track cells within the bioartificial myocardial tissue graft in vitro and post implant and assess viability and distribution.

scholarly journals α11β1 Integrin-Dependent Regulation of Periodontal Ligament Function in the Erupting Mouse Incisor

2007 ◽  
Vol 27 (12) ◽  
pp. 4306-4316 ◽  
Author(s):  
Svetlana N. Popova ◽  
Malgorzata Barczyk ◽  
Carl-Fredrik Tiger ◽  
Wouter Beertsen ◽  
Paola Zigrino ◽  
...  
Keyword(s):  
Periodontal Ligament ◽  
Tooth Movement ◽  
Tooth Eruption ◽  
Collagen I ◽  
Periodontal Ligament Fibroblasts ◽  
Primary Defect ◽  
Embryonic Fibroblasts ◽  
Mouse Incisor

ABSTRACT The fibroblast integrin α11β1 is a key receptor for fibrillar collagens. To study the potential function of α11 in vivo, we generated a null allele of the α11 gene. Integrin α11−/− mice are viable and fertile but display dwarfism with increased mortality, most probably due to severely defective incisors. Mutant incisors are characterized by disorganized periodontal ligaments, whereas molar ligaments appear normal. The primary defect in the incisor ligament leads to halted tooth eruption. α11β1-defective embryonic fibroblasts displayed severe defects in vitro, characterized by (i) greatly reduced cell adhesion and spreading on collagen I, (ii) reduced ability to retract collagen lattices, and (iii) reduced cell proliferation. Analysis of matrix metalloproteinase in vitro and in vivo revealed disturbed MMP13 and MMP14 synthesis in α11−/− cells. We show that α11β1 is the major receptor for collagen I on mouse embryonic fibroblasts and suggest that α11β1 integrin is specifically required on periodontal ligament fibroblasts for cell migration and collagen reorganization to help generate the forces needed for axial tooth movement. Our data show a unique role for α11β1 integrin during tooth eruption.

scholarly journals Regulation of Cell Types Within Testicular Organoids

Endocrinology ◽  
2021 ◽  
Vol 162 (4) ◽  
Author(s):  
Nathalia de Lima e Martins Lara ◽  
Sadman Sakib ◽  
Ina Dobrinski
Keyword(s):  
Reproductive Biology ◽  
Cell Types ◽  
3D Models ◽  
Research Area ◽  
Full Potential ◽  
3 Dimensional ◽  
Testicular Cells ◽  
Cell Niche

Abstract Organoids are 3-dimensional (3D) structures grown in vitro that emulate the cytoarchitecture and functions of true organs. Therefore, testicular organoids arise as an important model for research on male reproductive biology. These organoids can be generated from different sources of testicular cells, but most studies to date have used immature primary cells for this purpose. The complexity of the mammalian testicular cytoarchitecture and regulation poses a challenge for working with testicular organoids, because, ideally, these 3D models should mimic the organization observed in vivo. In this review, we explore the characteristics of the most important cell types present in the testicular organoid models reported to date and discuss how different factors influence the regulation of these cells inside the organoids and their outcomes. Factors such as the developmental or maturational stage of the Sertoli cells, for example, influence organoid generation and structure, which affect the use of these 3D models for research. Spermatogonial stem cells have been a focus recently, especially in regard to male fertility preservation. The regulation of the spermatogonial stem cell niche inside testicular organoids is discussed in the present review, as this research area may be positively affected by recent progress in organoid generation and tissue engineering. Therefore, the testicular organoid approach is a very promising model for male reproductive biology research, but more studies and improvements are necessary to achieve its full potential.

scholarly journals Effect of Static Compressive Force on Aldehyde Dehydrogenase Activity in Periodontal Ligament Fibroblasts

2021 ◽  
Vol 15 (1) ◽  
pp. 417-423
Author(s):  
Fabio Schemann-Miguel ◽  
Antonio Carlos Aloise ◽  
Silvana Gaiba ◽  
Lydia Masako Ferreira
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Periodontal Ligament ◽  
Tooth Movement ◽  
Compressive Force ◽  
Control Group ◽  
Aldh Activity ◽  
Periodontal Ligament Fibroblasts ◽  
Normal Tissues

Background: The application of static compressive forces to periodontal ligament fibroblasts (PDLFs) in vivo or in vitro has been linked to the expression of biochemical agents and local tissue modifications that could be involved in maintaining homeostasis during orthodontic movement. An approach used for identifying mesenchymal cells, or a subpopulation of progenitor cells in both tumoral and normal tissues, involves determining the activity of aldehyde dehydrogenase (ALDH). However, the role of subpopulations of PDLF-derived undifferentiated cells in maintaining homeostasis during tooth movement remains unclear. Objective: This study aimed at analyzing the effect of applying a static compressive force to PDLFs on the activity of ALDH in these cells. Methods: PDLFs were distributed into two groups: control group (CG), where fibroblasts were not submitted to compression, and experimental group (EG), where fibroblasts were submitted to a static compressive force of 4 g/mm2 for 6 hours. The compressive force was applied directly to the cells using a custom-built device. ALDH activity in the PDLFs was evaluated by a flow cytometry assay. Results: ALDH activity was observed in both groups, but was significantly lower in EG than in CG after the application of a static compressive force in the former. Conclusion: Application of a static compressive force to PDLFs decreased ALDH activity.

scholarly journals Forces driving cell sorting in Hydra

2017 ◽  
Author(s):  
Olivier Cochet-Escartin ◽  
Tiffany T. Locke ◽  
Winnie H. Shi ◽  
Robert E. Steele ◽  
Eva-Maria S. Collins
Keyword(s):  
Cell Sorting ◽  
Single Cells ◽  
Cell Types ◽  
Biological Organization ◽  
3 Dimensional ◽  
Physical Mechanisms ◽  
Summary Statement ◽  
Endodermal Cells

AbstractCell sorting, whereby a heterogeneous cell mixture organizes into distinct tissues, is a fundamental patterning process in development. So far, most studies of cell sorting have relied either on 2-dimensional cellular aggregates, in vitro situations that do not have a direct counterpart in vivo, or were focused on the properties of single cells. Here, we report the first multiscale experimental study on 3-dimensional regenerating Hydra aggregates, capable of reforming a full animal. By quantifying the kinematics of single cell and whole aggregate behaviors, we show that no differences in cell motility exist among cell types and that sorting dynamics follow a power law. Moreover, we measure the physical properties of separated tissues and determine their viscosities and surface tensions. Based on our experimental results and numerical simulations, we conclude that tissue interfacial tensions are sufficient to explain Hydra cell sorting. Doing so, we illustrate D’Arcy Thompson’s central idea that biological organization can be understood through physical principles, an idea which is currently re-shaping the field of developmental biology.Summary statementHydra regenerates after dissociation into single cells. We show how physical mechanisms can explain the first step of regeneration, whereby ectodermal and endodermal cells sort out to form distinct tissue layers.

scholarly journals PPARγ-Induced Global H3K27 Acetylation Maintains Osteo/Cementogenic Abilities of Periodontal Ligament Fibroblasts

2021 ◽  
Vol 22 (16) ◽  
pp. 8646
Author(s):  
Hang Yuan ◽  
Shigeki Suzuki ◽  
Shizu Hirata-Tsuchiya ◽  
Akiko Sato ◽  
Eiji Nemoto ◽  
...  
Keyword(s):  
Periodontal Ligament ◽  
Alveolar Bone ◽  
Key Factors ◽  
Active Chromatin ◽  
Periodontal Ligament Fibroblasts ◽  
Chromatin Region ◽  
Transcriptional Alterations ◽  
Pparγ Agonists

The periodontal ligament is a soft connective tissue embedded between the alveolar bone and cementum, the surface hard tissue of teeth. Periodontal ligament fibroblasts (PDLF) actively express osteo/cementogenic genes, which contribute to periodontal tissue homeostasis. However, the key factors maintaining the osteo/cementogenic abilities of PDLF remain unclear. We herein demonstrated that PPARγ was expressed by in vivo periodontal ligament tissue and its distribution pattern correlated with alkaline phosphate enzyme activity. The knockdown of PPARγ markedly reduced the osteo/cementogenic abilities of PDLF in vitro, whereas PPARγ agonists exerted the opposite effects. PPARγ was required to maintain the acetylation status of H3K9 and H3K27, active chromatin markers, and the supplementation of acetyl-CoA, a donor of histone acetylation, restored PPARγ knockdown-induced decreases in the osteo/cementogenic abilities of PDLF. An RNA-seq/ChIP-seq combined analysis identified four osteogenic transcripts, RUNX2, SULF2, RCAN2, and RGMA, in the PPARγ-dependent active chromatin region marked by H3K27ac. Furthermore, RUNX2-binding sites were selectively enriched in the PPARγ-dependent active chromatin region. Collectively, these results identified PPARγ as the key transcriptional factor maintaining the osteo/cementogenic abilities of PDLF and revealed that global H3K27ac modifications play a role in the comprehensive osteo/cementogenic transcriptional alterations mediated by PPARγ.

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