Rapid changes in the extracellular matrix accompany in vitro palatal shelf remodelling

1993 ◽  
Vol 188 (1) ◽  
Author(s):  
J. Morris-Wiman ◽  
L. Brinkley
Author(s):  
J. Roemer ◽  
S.R. Simon

We are developing an in vitro interstitial extracellular matrix (ECM) system for study of inflammatory cell migration. Falcon brand Cyclopore membrane inserts of various pore sizes are used as a support substrate for production of ECM by R22 rat aortic smooth muscle cells. Under specific culture conditions these cells produce a highly insoluble matrix consisting of typical interstitial ECM components, i.e.: types I and III collagen, elastin, proteoglycans and fibronectin.


1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.


1997 ◽  
Vol 78 (02) ◽  
pp. 934-938 ◽  
Author(s):  
Hsiun-ing Chen ◽  
Yueh-I Wu ◽  
Yu-Lun Hsieh ◽  
Guey-Yueh Shi ◽  
Meei-Jyh Jiang ◽  
...  

SummaryTo investigate whether the endothelium-platelet interactions may be altered by plasminogen activation, cultured human umbilical vein endothelial cells (ECs) were treated with tissue-type plasminogen activator (t-PA) in the presence of plasminogen, and platelet adhesion to ECs was subsequently measured by using a tapered flow chamber. Our results demonstrated that platelets adhered more readily to t-PA treated EC monolayer than to the control monolayer at all shear stress levels tested. This phenomenon was treatment time-dependent and dose-dependent, and it could be blocked by adding plasmin inhibitors, such as e-amino caproic acid and aprotinin. Adherent platelets on t-PA treated EC monolayer underwent more severe shape change than those on the control monolayer. While the extracellular matrix directly treated with t-PA attracted less platelets than the control matrix did, platelet adhesion to the matrix that was produced by t-PA-treated ECs was unaltered. These data suggest that t-PA treatment on ECs compromised antiplatelet-adhesion capability on their apical surface without altering the reactivity of their extracellular matrix towards platelets.


1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.


2021 ◽  
Vol 11 (6) ◽  
pp. 555
Author(s):  
Hammam Ibrahim Fageeh ◽  
Hytham N. Fageeh ◽  
Shankargouda Patil

Background: Periodontitis is an inflammatory condition of the tooth-supporting structures initiated and perpetuated by pathogenic bacteria present in the dental plaque biofilm. In periodontitis, immune cells infiltrate the periodontium to prevent bacterial insult. Macrophages derived from monocytes play an important role in antigen presentation to lymphocytes. However, they are also implicated in causing periodontal destruction and bystander damage to the host tissues. Objectives: The objective of the present study was to quantify the cytokine profile of gingival crevicular fluid (GCF) samples obtained from patients with periodontitis. The study further aimed to assess if GCF of periodontitis patients could convert CD14+ monocytes into macrophages of destructive phenotype in an in vitro setting. The secondary objectives of the study were to assess if macrophages that resulted from GCF treatment of monocytes could affect the synthetic properties, stemness, expression of extracellular matrix proteins, adhesion molecules expressed by gingival stem cells, gingival mesenchymal stromal cells, and osteoblasts. Methods: GCF, blood, and gingival tissue samples were obtained from periodontitis subjects and healthy individuals based on specific protocols. Cytokine profiles of the GCF samples were analyzed. CD14+ monocytes were isolated from whole blood, cultured, and treated with the GCF of periodontitis patients to observe if they differentiated into macrophages. Further, the macrophages were assessed for a phenotype by surface marker analysis and cytokine assays. These macrophages were co-cultured with gingival stem cells, epithelial, stromal cells, and osteoblasts to assess the effects of the macrophages on the synthetic activity of the cells. Results: The GCF samples of periodontitis patients had significantly higher levels of IFN gamma, M-CSF, and GM-CSF. Administration of the GCF samples to CD14+ monocytes resulted in their conversion to macrophages that tested positive for CD80, CD86, and CD206. These macrophages produced increased levels of IL-1β, TNF-α, and IL-6. Co-culture of the macrophages with gingival stem cells, epithelial cells, and stromal cells resulted in increased cytotoxicity and apoptotic rates to the gingival cells. A reduced expression of markers related to stemness, extracellular matrix, and adhesion namely OCT4, NANOG, KRT5, POSTN, COL3A1, CDH1, and CDH3 were seen. The macrophages profoundly affected the production of mineralized nodules by osteoblasts and significantly reduced the expression of COL1A1, OSX, and OCN genes. Conclusion: In periodontitis patients, blood-derived monocytes transform into macrophages of a destructive phenotype due to the characteristic cytokine environment of their GCF. Further, the macrophages affect the genotype and phenotype of the resident cells of the periodontium, aggravate periodontal destruction, as well as jeopardize periodontal healing and resolution of inflammation.


2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S34-S34
Author(s):  
Ren Mao ◽  
Genevieve Doyon ◽  
Ilyssa Gordon ◽  
Jiannan Li ◽  
Sinan Lin ◽  
...  

Abstract Background and Aims Creeping fat, the wrapping of mesenteric fat around the bowel wall, is a typical feature of Crohn’s disease, and is associated with stricture formation and bowel obstruction. How creeping fat forms is unknown, and we interrogated potential mechanisms using novel intestinal tissue and cell interaction systems. Methods Tissues from normal, ulcerative colitis, non-strictured and strictured Crohn’s disease intestinal specimens were obtained. Fresh and decellularized tissue, mesenteric fat explants, primary human adipocytes, pre-adipocytes, muscularis propria cells, and native extracellular matrix were used in multiple ex vivo and in vitro systems involving cell growth, differentiation and migration, proteomics, and integrin expression. Results Crohn’s disease muscularis propria cells produced an extracellular matrix scaffold which is in direct spatial and functional contact with the immediately overlaid creeping fat. The scaffold contained multiple proteins, but only fibronectin production was singularly upregulated by TGF-b1. The muscle cell-derived matrix triggered migration of pre-adipocytes out of mesenteric fat, fibronectin being the dominant factor responsible for their migration. Blockade of α5β1 on the pre-adipocyte surface inhibited their migration out of mesenteric fat and on 3D decellularized intestinal tissue extracellular matrix. Conclusion Crohn’s disease creeping fat appears to result from the migration of pre-adipocytes out of mesenteric fat and differentiation into adipocytes in response to an increased production of fibronectin by activated muscularis propria cells. These new mechanistic insights may lead to novel approaches for prevention of creeping fat-associated stricture formation.


Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 135
Author(s):  
Pau Urdeitx ◽  
Mohamed H. Doweidar

Mechanical and electrical stimuli play a key role in tissue formation, guiding cell processes such as cell migration, differentiation, maturation, and apoptosis. Monitoring and controlling these stimuli on in vitro experiments is not straightforward due to the coupling of these different stimuli. In addition, active and reciprocal cell–cell and cell–extracellular matrix interactions are essential to be considered during formation of complex tissue such as myocardial tissue. In this sense, computational models can offer new perspectives and key information on the cell microenvironment. Thus, we present a new computational 3D model, based on the Finite Element Method, where a complex extracellular matrix with piezoelectric properties interacts with cardiac muscle cells during the first steps of tissue formation. This model includes collective behavior and cell processes such as cell migration, maturation, differentiation, proliferation, and apoptosis. The model has employed to study the initial stages of in vitro cardiac aggregate formation, considering cell–cell junctions, under different extracellular matrix configurations. Three different cases have been purposed to evaluate cell behavior in fibered, mechanically stimulated fibered, and mechanically stimulated piezoelectric fibered extra-cellular matrix. In this last case, the cells are guided by the coupling of mechanical and electrical stimuli. Accordingly, the obtained results show the formation of more elongated groups and enhancement in cell proliferation.


Sign in / Sign up

Export Citation Format

Share Document