scholarly journals Relevance of osteoclast-specific enzyme activities in cell-based in vitro resorption assays

2017 ◽  
Vol 33 ◽  
pp. 28-42 ◽  
Author(s):  
A Bernhardt ◽  
◽  
K Koperski ◽  
M Schumacher ◽  
M Gelinsky
Keyword(s):  
Enzyme Activities ◽  
Specific Enzyme ◽  
In Vitro Resorption

scholarly journals Influence of Cu2+ on Osteoclast Formation and Activity In Vitro

2021 ◽  
Vol 22 (5) ◽  
pp. 2451
Author(s):  
Anne Bernhardt ◽  
Jana Bacova ◽  
Uwe Gbureck ◽  
Michael Gelinsky
Keyword(s):  
Gene Expression ◽  
Enzyme Activities ◽  
Bone Matrix ◽  
Antimicrobial Properties ◽  
Osteoclast Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Specific Enzyme ◽  
Cytotoxic Effects ◽  
Resorptive Activity

Background: Copper-containing biomaterials are increasingly applied for bone regeneration due to their pro-angiogenetic, pro-osteogenetic and antimicrobial properties. Therefore, the effect of Cu2+ on osteoclasts, which play a major role in bone remodeling was studied in detail. Methods: Human primary osteoclasts, differentiated from human monocytes were differentiated or cultivated in the presence of Cu2+. Osteoclast formation and activity were analyzed by measurement of osteoclast-specific enzyme activities, gene expression analysis and resorption assays. Furthermore, the glutathione levels of the cells were checked to evaluate oxidative stress induced by Cu2+. Results: Up to 8 µM Cu2+ did not induce cytotoxic effects. Activity of tartrate-resistant acid phosphatase (TRAP) was significantly increased, while other osteoclast specific enzyme activities were not affected. However, gene expression of TRAP was not upregulated. Resorptive activity of osteoclasts towards dentin was not changed in the presence of 8 µM Cu2+ but decreased in the presence of extracellular bone matrix. When Cu2+ was added to mature osteoclasts TRAP activity was not increased and resorption decreased only moderately. The glutathione level of both differentiating and mature osteoclasts was significantly decreased in the presence of Cu2+. Conclusions: Differentiating and mature osteoclasts react differently to Cu2+. High TRAP activities are not necessarily related to high resorption.

The effect of fibrolytic enzyme application on the rate and extent of alfalfa stem fermentation, assessed in vitro

2002 ◽  
Vol 2002 ◽  
pp. 209-209 ◽  
Author(s):  
D. Colombatto ◽  
F. L. Mould ◽  
M. K. Bhat ◽  
E. Owen
Keyword(s):  
Enzyme Activities ◽  
Enzyme Preparation ◽  
Specific Enzyme ◽  
Enzyme Preparations ◽  
Commercial Enzyme ◽  
Application Rates ◽  
Enzyme Application ◽  
Different Levels

A number of fibrolytic enzyme preparations have been shown to increase the rate and extent of fermentation of alfalfa fractions (Colombatto et al., 2000a). However, responses to enzyme addition have been mixed and several factors are believed to be involved. Among these, specific enzyme activities and application rates are very important. The present study examined a commercial enzyme preparation already established as effective, for its ability to increase the rate and extent of in vitro fermentation of alfalfa stems, when applied at different levels.

In vitro Inhibition of Pancreatic Enzyme Activities by Dietary Fiber

Digestion ◽  
1982 ◽  
Vol 24 (1) ◽  
pp. 54-59 ◽  
Author(s):  
G. Isaksson ◽  
I. Lundquist ◽  
I. Ihse
Keyword(s):  
Dietary Fiber ◽  
Enzyme Activities ◽  
Pancreatic Enzyme ◽  
In Vitro Inhibition

A novel compound active against SARS-CoV-2 targeting Uridylate-specific endoribonuclease (NendoU/NSP15): In silico and in vitro investigations

2021 ◽  
Author(s):  
Sumit Kumar ◽  
Yash Gupta ◽  
Samantha Zak ◽  
Charu Upadhyay ◽  
Neha Sharma ◽  
...  
Keyword(s):  
Virtual Screening ◽  
High Throughput ◽  
In Silico ◽  
Specific Enzyme ◽  
Cyclic Phosphates ◽  
High Throughput Virtual Screening

NendoU (NSP15) is an Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond. Our in-house library was subjected to high throughput virtual screening (HTVS) to identify compounds...

scholarly journals In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ganiyu Oboh ◽  
Ayokunle O. Ademosun ◽  
Adedayo O. Ademiluyi ◽  
Olasunkanmi S. Omojokun ◽  
Esther E. Nwanna ◽  
...  
Keyword(s):  
Enzyme Activities ◽  
Theobroma Cacao ◽  
Antioxidant Property ◽  
Cocoa Bean ◽  
Dependent Manner ◽  
Converting Enzyme ◽  
Angiotensin I Converting Enzyme ◽  
Dose Dependent

Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension.

Study of yolk-sac endoderm organogenesis in the chick using a specific enzyme (cysteine lyase) as a marker of cell differentiation

Development ◽  
1973 ◽  
Vol 29 (1) ◽  
pp. 159-174
Author(s):  
Nelly Bennett
Keyword(s):  
Cell Differentiation ◽  
Blood Cells ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Specific Enzyme ◽  
Cell Proliferation And Differentiation ◽  
Lyase Activity ◽  
Morphological Specialization

The detection of a specific enzyme (cysteine lyase) of the yolk-sac endoderm by a very sensitive method is employed to characterize cell differentiation during the early stages of endoderm organogenesis in the chick. The first cells to contain active cysteine lyase are found in the germ wall at the primitive streak stage. In vivo observations establish a relation between the morphological specialization and organization of endodermal cells, their loss of mitotic activity and the increase in cysteine lyase activity. They suggest an influence of the mesoderm on endoderm differentiation. In vitro experiments confirm the existence in the yolk-sac endoderm of an incompatibility between cell proliferation and differentiation, as well as the action of the mesoderm on both the structural organization of the endoblast and the appearance of cysteine lyase; this last action seems to be due mainly to blood cells; chicken and rabbit blood cells are equally active. The problems of the origin of the endoderm and of the interactions occurring during the organogenesis of the yolk-sac endoderm are discussed.

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