Maintenance of regional histodifferentiation patterns and a spatially restricted expression of type X collagen in rat Meckel’s cartilage explants in vitro

1999 ◽  
Vol 44 (6) ◽  
pp. 489-497 ◽  
Author(s):  
Kun Sung Chung ◽  
Ichiro Nishimura
1995 ◽  
Vol 170 (2) ◽  
pp. 387-396 ◽  
Author(s):  
Kun Sung Chung ◽  
Howard H. Park ◽  
Kang Ting ◽  
Hiroko Takita ◽  
Suneel S. Apte ◽  
...  

2020 ◽  
pp. 002203452096011
Author(s):  
M. Farahat ◽  
G.A.S. Kazi ◽  
E.S. Hara ◽  
T. Matsumoto

During orofacial tissue development, the anterior and posterior regions of the Meckel’s cartilage undergo mineralization, while the middle region undergoes degeneration. Despite the interesting and particular phenomena, the mechanisms that regulate the different fates of Meckel’s cartilage, including the effects of biomechanical cues, are still unclear. Therefore, the purpose of this study was to systematically investigate the course of Meckel’s cartilage during embryonic development from a biomechanical perspective. Histomorphological and biomechanical (stiffness) changes in the Meckel’s cartilage were analyzed from embryonic day 12 to postnatal day 0. The results revealed remarkable changes in the morphology and size of chondrocytes, as well as the occurrence of chondrocyte burst in the vicinity of the mineralization site, an often-seen phenomenon preceding endochondral ossification. To understand the effect of biomechanical cues on Meckel’s cartilage fate, a mechanically tuned 3-dimensional hydrogel culture system was used. At the anterior region, a moderately soft environment (10-kPa hydrogel) promoted chondrocyte burst and ossification. On the contrary, at the middle region, a more rigid environment (40-kPa hydrogel) enhanced cartilage degradation by inducing a higher expression of MMP-1 and MMP-13. These results indicate that differences in the biomechanical properties of the surrounding environment are essential factors that distinctly guide the mineralization and degradation of Meckel’s cartilage and would be valuable tools for modulating in vitro cartilage and bone tissue engineering.


Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 903-917 ◽  
Author(s):  
L. Shum ◽  
Y. Sakakura ◽  
P. Bringas ◽  
W. Luo ◽  
M.L. Snead ◽  
...  

Mutations associated with genes of the EGF superfamily are implicated in facial malformations arising from abnormal development of the first branchial arch. EGF and EGF receptor (EGFr) transcripts are expressed in the mouse embryonic first branchial arch and derivatives from E9 through E15. EGF transcripts are localized to ectomesenchymal cells associated with precartilage, cartilage, bone and tooth-forming cells. EGF and EGFr proteins co-localize to the same cells suggesting an autocrine regulation. To test whether EGF effects the timing and positional information required for Meckel's cartilage (MC) and tooth development, we cultured E10 mandibular explants in serumless, chemically defined medium with either antisense or sense EGF oligodeoxynucleotides. Antisense inhibition of EGF expression produces bilaterally symmetrical Fusilli-form dysmorphogenesis of MC and decreases tooth bud size; these effects are reversed by the addition of exogenous EGF to the culture medium. Tyrphostin RG 50864, which inhibits EGF receptor kinase activity, inhibits EGF stimulation of tyrosine phosphorylation in a concentration-dependent manner and severely retards mandibular development yet increases tooth size. These findings support the hypothesis that endogenous EGF and EGF-like proteins provide signalling to regulate the size and shape both of cartilage and tooth formation during craniofacial morphogenesis.


2019 ◽  
Vol 20 (11) ◽  
pp. 920-933 ◽  
Author(s):  
Lucía Gato-Calvo ◽  
Tamara Hermida-Gómez ◽  
Cristina R. Romero ◽  
Elena F. Burguera ◽  
Francisco J. Blanco

Background: Platelet Rich Plasma (PRP) has recently emerged as a potential treatment for osteoarthritis (OA), but composition heterogeneity hampers comparison among studies, with the result that definite conclusions on its efficacy have not been reached. Objective: 1) To develop a novel methodology to prepare a series of standardized PRP releasates (PRP-Rs) with known absolute platelet concentrations, and 2) To evaluate the influence of this standardization parameter on the anti-inflammatory properties of these PRP-Rs in an in vitro and an ex vivo model of OA. Methods: A series of PRPs was prepared using the absolute platelet concentration as the standardization parameter. Doses of platelets ranged from 0% (platelet poor plasma, PPP) to 1.5·105 platelets/µl. PRPs were then activated with CaCl2 to obtain releasates (PRP-R). Chondrocytes were stimulated with 10% of each PRP-R in serum-free culture medium for 72 h to assess proliferation and viability. Cells were co-stimulated with interleukin (IL)-1β (5 ng/ml) and 10% of each PRP-R for 48 h to determine the effects on gene expression, secretion and intra-cellular content of common markers associated with inflammation, catabolism and oxidative stress in OA. OA cartilage explants were co-stimulated with IL-1β (5 ng/ml) and 10% of either PRP-R with 0.75·105 platelets/µl or PRP-R with 1.5·105 platelets/µl for 21 days to assess matrix inflammatory degradation. Results: Chondrocyte viability was not affected, and proliferation was dose-dependently increased. The gene expression of all pro-inflammatory mediators was significantly and dose-independently reduced, except for that of IL-1β and IL-8. Immunoblotting corroborated this effect for inducible NO synthase (NOS2). Secreted matrix metalloproteinase-13 (MMP-13) was reduced to almost basal levels by the PRP-R from PPP. Increasing platelet dosage led to progressive loss to this anti-catabolic ability. Safranin O and toluidine blue stains supported the beneficial effect of low platelet dosage on cartilage matrix preservation. Conclusion: We have developed a methodology to prepare PRP releasates using the absolute platelet concentration as the standardization parameter. Using this approach, the composition of the resulting PRP derived product is independent of the donor initial basal platelet count, thereby allowing the evaluation of its effects objectively and reproducibly. In our OA models, PRP-Rs showed antiinflammatory, anti-oxidant and anti-catabolic properties. Platelet enrichment could favor chondrocyte proliferation but is not necessary for the above effects and could even be counter-productive.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 426.1-426
Author(s):  
T. Hügle ◽  
S. Nasi ◽  
D. Ehirchiou ◽  
P. Omoumi ◽  
A. So ◽  
...  

Background:Fibrin(ogen) maintains inflammation in various disorders but has never been linked to cartilage damage in rheumatoid arthritis (RA) or other forms of inflammatory arthritis.Objectives:To investigate the role of fibrin deposition on cartilage integrity in arthritis.Methods:Fibrin deposition on knee cartilage was analyzed by immunohistochemistry in RA patients and in murine adjuvant-induced arthritis (AIA). In chondrocytes, fibrinogen expression (Fgα, Fgβ, Fgγ) and procoagulant activity were evaluated by qRT-PCR and turbidimetry respectively. Fibrin-induced catabolic genes were assessed by qRT-PCR in chondrocytes. Fibrin-mediated chondro-synovial adhesion (CSA) with subsequent cartilage tears was studied in co-cultures of human RA cartilage with autologous synoviocytes, in the AIA model, and by MRI. The link between fibrin and calcification was examined in human RA cartilage stained for calcific deposits and in vitro in fibrinogen-stimulated chondrocytes.Results:Fibrin deposition on cartilage correlated with the severity of cartilage damage in human RA explants and in AIA wildtype (WT) mice, while fibrinogen deficient (Fg-/-) mice were protected. Accordingly, fibrin upregulated catabolic enzymes (Adamts5 and Mmp13) in chondrocytes. Secondly, CSA was present in fibrin-rich and damaged cartilage in AIA WT but not in Fg-/- mice. In line, autologous human synoviocytes, cultured on RA cartilage explants, adhered exclusively to fibrin-positive degraded areas. Gadolinium-enhanced MRI of human joints showed contrast-enhancement along cartilage surface in RA patients but not in controls. Finally, fibrin co-localized with calcification in human RA cartilage and triggered chondrocyte mineralization inducing pro-calcification genes (Anx5, Pit1, Pc1) and cytokine (IL-6). Although at a much lesser extent, we observed similar fibrin-mediated mechanisms in osteoarthritis (OA).Conclusion:Fibrin deposition directly impacts on cartilage integrity via induction of catabolism, mechanical stress, and calcification. Potentially, fibrin is a key factor of cartilage damage occurring in RA as a secondary consequence of inflammation.Disclosure of Interests:None declared


2011 ◽  
Vol 218 (5) ◽  
pp. 517-533 ◽  
Author(s):  
Tamaki Yokohama-Tamaki ◽  
Takashi Maeda ◽  
Tetsuya S. Tanaka ◽  
Shunichi Shibata

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