scholarly journals Endogenous Enzymatic Activity of Primary and Permanent Dentine

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4043
Author(s):  
Tatjana Maravic ◽  
Lorenzo Breschi ◽  
Federica Paganelli ◽  
Giulio Alessandri Bonetti ◽  
Stefano Martina ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Protein Extraction ◽  
Tooth Development ◽  
Active Form ◽  
Gelatinolytic Activity ◽  
Hybrid Layer ◽  
Permanent Molars ◽  
In Situ Zymography ◽  
Post Hoc

Matrix metalloproteinases (MMPs) play an important role in tooth development and influence caries development and hybrid layer degradation. Literature is scant on the differences in the activity of MMPs between primary and permanent dentine. Accordingly, the aim of the present study was to investigate endogenous gelatinolytic activity in primary and permanent dentine. Separate batches of dentine powder were obtained from intact human primary and permanent molars (n = 6). Each batch was divided in two subgroups: (1) mineralised; and (2) demineralised with 10% H3PO4. After protein extraction, gelatine zymography was performed. Furthermore, in situ zymography was performed on dentine sections of the same groups (n = 3). The slices were polished, covered with fluorescein-conjugated gelatine and evaluated using a confocal microscope. In situ zymography data were analysed using two-way analysis of variance and post hoc Holm–Šidák statistics (α = 0.05). Primary dentine showed poorly defined bands in the zymograms that vaguely corresponded to the pro-form and active form of MMP-2 and the pro-form of MMP-9. In permanent dentine, demineralised powder demonstrated stronger gelatinolytic activity than mineralised powder. In situ zymography identified stronger enzymatic activity in primary etched dentine (p < 0.05). Stronger enzymatic activity recorded in primary dentine may be related to the differences in morphology and composition between primary and permanent dentine.

scholarly journals MMP Activity in the Hybrid Layer Detected with in situ Zymography

2012 ◽  
Vol 91 (5) ◽  
pp. 467-472 ◽  
Author(s):  
A. Mazzoni ◽  
F.D. Nascimento ◽  
M. Carrilho ◽  
I. Tersariol ◽  
V. Papa ◽  
...  
Keyword(s):  
Hybrid Layer ◽  
In Situ Zymography

Dentin Cross-linking Effect of Carbodiimide After 5 Years

2021 ◽  
pp. 002203452110147
Author(s):  
T. Maravic ◽  
E. Mancuso ◽  
A. Comba ◽  
V. Checchi ◽  
L. Generali ◽  
...  
Keyword(s):  
Bond Strength ◽  
Enzymatic Activity ◽  
Artificial Saliva ◽  
Cross Linking ◽  
Chemical Profile ◽  
Etch And Rinse ◽  
Group 3 ◽  
In Situ Zymography ◽  
Group 1

Carbodiimide (EDC)–based dentin primers preserve hybrid layer (HL) integrity. However, aging >1 y has not been investigated. The present study examined whether the cross-linking effect of EDC was reflected in dentin bond strength, endogenous enzymatic activity, and the chemical profile of the HL after 5-y aging in artificial saliva. Noncarious human third molars ( N = 42) were cut to expose middle/deep coronal dentin and treated as follows: group 1, dentin etched with 35% H3PO4, pretreated with a 0.3M aqueous EDC primer for 1 min and restored with XP Bond (Dentsply Sirona); group 2, as in group 1 but without EDC pretreatment; group 3, Clearfil SE Bond (Kuraray-Noritake) primer applied to dentin surface, followed by EDC pretreatment as in group 1 and application of bond; group 4, as in group 3 without EDC pretreatment. After composite buildup, the specimens were cut into sticks or slabs, depending on the experiment. All tests were performed at baseline (T0) and after 5 y of aging (T5) in artificial saliva at 37 °C. Microtensile bond strength (µTBS) was tested at a crosshead speed of 1 mm/min until failure. Endogenous enzymatic activity was investigated with in situ zymography. The chemical profile of HL was determined via Raman spectroscopy. Three-way analysis of variance and post hoc Tukey test were used to analyze µTBS and in situ zymography data (α = 0.05). EDC pretreatment and aging significantly influenced µTBS and in situ zymography results ( P < 0.05). Higher bond strength and lower gelatinolytic activity were identified in the EDC-treated groups at T5 ( P < 0.05), especially in the etch-and-rinse groups. Raman spectra revealed less defined amide III peaks in control specimens at T5. The EDC cross-linking effect persisted in the HL for 5 y in terms of bond strength, collagen structure preservation, and dentinal enzyme silencing.

Unbalanced collagenases/TIMP-1 expression and epithelial apoptosis in experimental lung fibrosis

2003 ◽  
Vol 285 (5) ◽  
pp. L1026-L1036 ◽  
Author(s):  
Victor Ruiz ◽  
Rosa Ma. Ordóñez ◽  
Jaime Berumen ◽  
Remedios Ramírez ◽  
Bruce Uhal ◽  
...  
Keyword(s):  
Interstitial Cell ◽  
Transforming Growth Factor ◽  
Morphological Changes ◽  
Protein Localization ◽  
Active Form ◽  
Transforming Growth Factor Β ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Gelatinolytic Activity ◽  
Fibrotic Response

In this study, we examined the sequential expression of several matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and growth factors as well as the presence of apoptosis in a model of pulmonary fibrosis induced in rats with paraquat and hyperoxia. Animals showing neither clinical nor morphological changes with this double aggression were classified as “resistant”. Rats were killed at 1, 2, 3, and 6 wk, and lungs were used for collagen content, gene expression by real-time PCR, gelatinolytic activity by zymography, apoptosis by in situ DNA fragmentation, and protein localization by immunohistochemistry. Our results showed a significant decrease of collagenases MMP-8 and MMP-13, with an increase of TIMP-1 and transforming growth factor-β. Immunoreactive TIMP-1 was increased in experimental rats and primarily localized in alveolar macrophages. Expression of gelatinases MMP-2 and MMP-9 mRNAs was not affected, but lung zymography revealed an increase in progelatinase B, progelatinase A, and its active form. Epithelial apoptosis was evident from the first week, whereas at later periods, interstitial cell apoptosis was also noticed. Resistant animals behave as controls. These findings suggest that an imbalance between collagenases and TIMPs, excessive gelatinolytic activity, and epithelial apoptosis participate in the fibrotic response in this experimental model.

scholarly journals Endogenous Enzymatic Activity in Dentin Treated with a Chitosan Primer

2021 ◽  
Vol 22 (16) ◽  
pp. 8852
Author(s):  
Tatjana Maravić ◽  
Eugenia Baena ◽  
Claudia Mazzitelli ◽  
Uroš Josić ◽  
Edoardo Mancuso ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Uv Light ◽  
Reducing Conditions ◽  
Sds Page ◽  
Human Dentin ◽  
Zymographic Analysis ◽  
In Situ Zymography ◽  
Experimental Group ◽  
Incubation Buffer

The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ zymography. Human dentin was frozen and ground in a miller. Dentin powder aliquots were demineralized with phosphoric acid and treated with three different concentrations of lyophilized chitosan polymer (1, 0.5 and 0.1 wt%) dissolved in distilled water. Dentin proteins were extracted from each experimental group and electrophoresed under non-reducing conditions in 10% SDS-PAGE containing fluorescein-labeled gelatin. After 48 h in the incubation buffer at 37 °C, proteolytic activity was registered under long-wave UV light scanner and quantified by using Image J software. Furthermore, additional teeth (n = 4) were prepared for the in situ zymographic analysis in unrestored as well as restored dentin pretreated with the same chitosan primers. The registered enzymatic activity was directly proportional to the chitosan concentration and higher in the restored dentin groups (p < 0.05), except for the 0.1% chitosan primer. Chitosan 0.1% only showed faint expression of enzymatic activity compared to 1% and 0.5% concentrations. Chitosan 0.1% dissolved in water can produce significant reduction in MMPs activity and could possibly contribute to bond strength preservation over time.

scholarly journals DnaA, the Initiator of Escherichia coliChromosomal Replication, Is Located at the Cell Membrane

2000 ◽  
Vol 182 (9) ◽  
pp. 2604-2610 ◽  
Author(s):  
Gillian Newman ◽  
Elliott Crooke
Keyword(s):  
Cell Membrane ◽  
Spatial Organization ◽  
Active Form ◽  
Chromosomal Replication ◽  
E Coli ◽  
Dnaa Protein ◽  
Section Electron ◽  
Acidic Phospholipids

ABSTRACT Given the lack of a nucleus in prokaryotic cells, the significance of spatial organization in bacterial chromosome replication is only beginning to be fully appreciated. DnaA protein, the initiator of chromosomal replication in Escherichia coli, is purified as a soluble protein, and in vitro it efficiently initiates replication of minichromosomes in membrane-free DNA synthesis reactions. However, its conversion from a replicatively inactive to an active form in vitro occurs through its association with acidic phospholipids in a lipid bilayer. To determine whether the in situ residence of DnaA protein is cytoplasmic, membrane associated, or both, we examined the cellular location of DnaA using immunogold cryothin-section electron microscopy and immunofluorescence. Both of these methods revealed that DnaA is localized at the cell membrane, further suggesting that initiation of chromosomal replication in E. coli is a membrane-affiliated event.

scholarly journals Timing of Mouse Molar Formation Is Independent of Jaw Length Including Retromolar Space

2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Daisy (Jihyung) Ko ◽  
Tess Kelly ◽  
Lacey Thompson ◽  
Jasmene K. Uppal ◽  
Nasim Rostampour ◽  
...  
Keyword(s):  
Onset Time ◽  
Ct Scanning ◽  
Micro Ct ◽  
Third Molars ◽  
Developmental Duration ◽  
Dental Lamina ◽  
Permanent Molars ◽  
Dental Epithelium ◽  
Space Conditions

For humans and other mammals to eat effectively, teeth must develop properly inside the jaw. Deciphering craniodental integration is central to explaining the timely formation of permanent molars, including third molars which are often impacted in humans, and to clarifying how teeth and jaws fit, function and evolve together. A factor long-posited to influence molar onset time is the jaw space available for each molar organ to form within. Here, we tested whether each successive molar initiates only after a minimum threshold of space is created via jaw growth. We used synchrotron-based micro-CT scanning to assess developing molars in situ within jaws of C57BL/6J mice aged E10 to P32, encompassing molar onset to emergence. We compared total jaw, retromolar and molar lengths, and molar onset times, between upper and lower jaws. Initiation time and developmental duration were comparable between molar upper and lower counterparts despite shorter, slower-growing retromolar space in the upper jaw, and despite size differences between upper and lower molars. Timing of molar formation appears unmoved by jaw length including space. Conditions within the dental lamina likely influence molar onset much more than surrounding jaw tissues. We theorize that molar initiation is contingent on sufficient surface area for the physical reorganization of dental epithelium and its invagination of underlying mesenchyme.

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