Zinc Inhibits Collagenolysis by Cathepsin K and Matrix Metalloproteinases in Demineralized Dentin Matrix

2017 ◽  
Vol 51 (6) ◽  
pp. 576-581 ◽  
Author(s):  
Pinar Altinci ◽  
Roda Seseogullari-Dirihan ◽  
Gulsen Can ◽  
David Pashley ◽  
Arzu Tezvergil-Mutluay

The enzymatic degradation of dentin organic matrix occurs via both the action of matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs). Zinc can prevent collagen hydrolysis by MMPs. However, its effect on the activity of dentin-bound CCs is not known. The aim of this study was to investigate the effect of zinc on matrix-bound cathepsin K and MMP activity in dentin. Completely demineralized dentin beams were divided into test groups (n = 9) and incubated at 37°C in an incubation media (1 mL) containing ZnCl2 of 0.02 (physiological level, control), 0.2, 0.5, 1, 5, 10, 20, 30, or 40 mM. The dry mass changes of the beams were determined, and incubation media were analyzed for cathepsin K- and MMP-specific collagen degradation end products - CTX (C-terminal cross-linked telopeptide of type I collagen) and ICTP (cross-linked carboxy-terminal telopeptide of type I collagen) - at 1, 3, and 7 days of incubation. The mass loss of the beams decreased when the zinc level in the incubation media was ≥5 mM (p < 0.05). The release of liberated collagen degradation telopeptides decreased in accordance with the decrease in the mass loss rates of the beams. Cathepsin K-induced dentin collagen degradation can be strongly inhibited by zinc. Zinc levels of ≥5 mM can be considered as a reliable threshold for the stabilization of dentin matrices.

2015 ◽  
Vol 49 (3) ◽  
pp. 193-208 ◽  
Author(s):  
Leo Tjäderhane ◽  
Marília Afonso Rabelo Buzalaf ◽  
Marcela Carrilho ◽  
Catherine Chaussain

Dentin organic matrix, with type I collagen as the main component, is exposed after demineralization in dentinal caries, erosion or acidic conditioning during adhesive composite restorative treatment. This exposed matrix is prone to slow hydrolytic degradation by host collagenolytic enzymes, matrix metalloproteinases (MMPs) and cysteine cathepsins. Here we review the recent findings demonstrating that inhibition of salivary or dentin endogenous collagenolytic enzymes may provide preventive means against progression of caries or erosion, just as they have been shown to retain the integrity and improve the longevity of resin composite filling bonding to dentin. This paper also presents the case that the organic matrix in caries-affected dentin may not be preserved as intact as previously considered. In partially demineralized dentin, MMPs and cysteine cathepsins with the ability to cleave off the terminal non-helical ends of collagen molecules (telopeptides) may lead to the gradual loss of intramolecular gap areas. This would seriously compromise the matrix ability for intrafibrillar remineralization, which is considered essential in restoring the dentin's mechanical properties. More detailed data of the enzymes responsible and their detailed function in dentin-destructive conditions may not only help to find new and better preventive means, but better preservation of demineralized dentin collagenous matrix may also facilitate true biological remineralization for the better restoration of tooth structural and mechanical integrity and mechanical properties.


2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Sylvie Desmarais ◽  
Frédéric Massé ◽  
M. David Percival

Abstract Cathepsin K (Cat K) degrades bone type I collagen and is a target for the pharmacological treatment of osteoporosis. Further roles for Cat K have been recently described, some of which are supported by the use of purportedly selective Cat K inhibitors in human and rodent cell-based assays. Twelve commercial and non-commercial Cat K inhibitors were profiled against a panel of purified human, rat, and mouse cysteine cathepsins and in two cell-based enzyme occupancy assays for activity against Cat K, B, and L. Ten inhibitors, including the carbohydrazide Cat K inhibitor II (Boc-Phe-Leu-NHNH-CO-NHNH-Leu-Z), the non-covalent K4b, and the epoxide NC-2300, have either little Cat K selectivity, or appear poorly cell penetrant. The amino-acetonitrile-containing inhibitors L-873724 and odanacatib show greater than 100-fold human Cat K enzyme selectivity and have similar IC50 values against each cathepsin in cell-based and enzyme assays. The basic inhibitor balicatib has greater cellular potencies than expected on the basis of purified enzyme assays. The accumulation of [14C]-balicatib in fibroblasts is blocked by prior treatment of the cells with NH4Cl, consistent with balicatib having lysosomotropic properties. These results support the use of L-873724 and odanacatib as tools to identify novel roles for Cat K using human cell-based systems, but suggest using caution in the interpretation of studies employing the other compounds.


2012 ◽  
Vol 40 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Ulvi K. Gursoy ◽  
Eija Könönen ◽  
Sisko Huumonen ◽  
Taina Tervahartiala ◽  
Pirkko J. Pussinen ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7233
Author(s):  
Yaroslava Robles-Bykbaev ◽  
Salvador Naya ◽  
Silvia Díaz-Prado ◽  
Daniel Calle-López ◽  
Vladimir Robles-Bykbaev ◽  
...  

This work proposes a method based on image analysis and machine and statistical learning to model and estimate osteocyte growth (in type I collagen scaffolds for bone regeneration systems) and the collagen degradation degree due to cellular growth. To achieve these aims, the mass of collagen -subjected to the action of osteocyte growth and differentiation from stem cells- was measured on 3 days during each of 2 months, under conditions simulating a tissue in the human body. In addition, optical microscopy was applied to obtain information about cellular growth, cellular differentiation, and collagen degradation. Our first contribution consists of the application of a supervised classification random forest algorithm to image texture features (the structure tensor and entropy) for estimating the different regions of interest in an image obtained by optical microscopy: the extracellular matrix, collagen, and image background, and nuclei. Then, extracellular-matrix and collagen regions of interest were determined by the extraction of features related to the progression of the cellular growth and collagen degradation (e.g., mean area of objects and the mode of an intensity histogram). Finally, these critical features were statistically modeled depending on time via nonparametric and parametric linear and nonlinear models such as those based on logistic functions. Namely, the parametric logistic mixture models provided a way to identify and model the degradation due to biological activity by estimating the corresponding proportion of mass loss. The relation between osteocyte growth and differentiation from stem cells, on the one hand, and collagen degradation, on the other hand, was determined too and modeled through analysis of image objects’ circularity and area, in addition to collagen mass loss. This set of imaging techniques, machine learning procedures, and statistical tools allowed us to characterize and parameterize type I collagen biodegradation when collagen acts as a scaffold in bone regeneration tasks. Namely, the parametric logistic mixture models provided a way to identify and model the degradation due to biological activity and thus to estimate the corresponding proportion of mass loss. Moreover, the proposed methodology can help to estimate the degradation degree of scaffolds from the information obtained by optical microscopy.


2009 ◽  
Vol 56 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Junfeng HAN ◽  
Tianhong LUO ◽  
Yanyun GU ◽  
Guo LI ◽  
Weiping JIA ◽  
...  

Bone ◽  
1989 ◽  
Vol 10 (6) ◽  
pp. 471 ◽  
Author(s):  
BM Thomson ◽  
SJ Atkinson ◽  
AM McGarrity ◽  
RM Hembry ◽  
JJ Reynolds ◽  
...  

2001 ◽  
Vol 204 (3) ◽  
pp. 443-455
Author(s):  
C. Faucheux ◽  
S. Nesbitt ◽  
M. Horton ◽  
J. Price

Deer antlers are a rare example of mammalian epimorphic regeneration. Each year, the antlers re-grow by a modified endochondral ossification process that involves extensive remodelling of cartilage by osteoclasts. This study identified regenerating antler cartilage as a site of osteoclastogenesis in vivo. An in vitro model was then developed to study antler osteoclast differentiation. Cultured as a high-density micromass, cells from non-mineralised cartilage supported the differentiation of large numbers of osteoclast-like multinucleated cells (MNCs) in the absence of factors normally required for osteoclastogenesis. After 48 h of culture, tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells (osteoclast precursors) were visible, and by day 14 a large number of TRAP-positive MNCs had formed (783+/−200 per well, mean +/− s.e.m., N=4). Reverse transcriptase/polymerase chain reaction (RT-PCR) showed that receptor activator of NF κ B ligand (RANKL) and macrophage colony stimulating factor (M-CSF) mRNAs were expressed in micromass cultures. Antler MNCs have the phenotype of osteoclasts from mammalian bone; they expressed TRAP, vitronectin and calcitonin receptors and, when cultured on dentine, formed F-actin rings and large resorption pits. When cultured on glass, antler MNCs appeared to digest the matrix of the micromass and endocytose type I collagen. Matrix metalloproteinase-9 (MMP-9) may play a role in the resorption of this non-mineralised matrix since it is highly expressed in 100 % of MNCs. In contrast, cathepsin K, another enzyme expressed in osteoclasts from bone, is only highly expressed in resorbing MNCs cultured on dentine. This study identifies the deer antler as a valuable model that can be used to study the differentiation and function of osteoclasts in adult regenerating mineralised tissues.


1987 ◽  
Vol 87 (2) ◽  
pp. 357-362
Author(s):  
J. Gavrilovic ◽  
R.M. Hembry ◽  
J.J. Reynolds ◽  
G. Murphy

A specific antiserum to purified rabbit tissue inhibitor of metalloproteinases (TIMP) was raised in sheep, characterized and used to investigate the role of TIMP in a model system. Chondrocytes and endothelial cells cultured on 14C-labelled type I collagen films and stimulated to produce collagenase were unable to degrade the films unless the anti-TIMP antibody was added. The degradation induced was inhibited by a specific anti-rabbit collagenase antibody. It was concluded that TIMP is a major regulatory factor in cell-mediated collagen degradation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Akia N. Parks ◽  
Juhi Nahata ◽  
Naomi-Eliana Edouard ◽  
Johnna S. Temenoff ◽  
Manu O. Platt
Keyword(s):  

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