scholarly journals Heparanase Modulation by Wingless/INT (Wnt)

2021 ◽  
Author(s):  
Carina Mucciolo Melo ◽  
Helena Bonciani Nader ◽  
Giselle Zenker Justo ◽  
Maria Aparecida Silva Pinhal
Keyword(s):  
Heparan Sulfate ◽  
Chinese Hamster ◽  
Beta Catenin ◽  
Ovary Cells ◽  
Protein Levels ◽  
Coated Plate ◽  
A Cell ◽  
Chloride Treatment

Abstract Heparanase is an endo-beta-glucuronidase, the only enzyme in mammals capable of cleaving heparan sulfate/heparin chains from proteoglycans. The oligosaccharides generated by heparanase present extensive biological functions since such oligosaccharides interact with adhesion molecules, growth factors, angiogenic factors and cytokines, modulating cell proliferation, migration, inflammation, and carcinogenesis. However, the regulation of heparanase activity is not fully understood. It is known that heparanase is synthesized as an inactive 65 kDa isoform and that post-translation processing forms an active 50 kDa enzyme. In the present study, we are interested in investigating whether heparinase is regulated by its own substrate as observed with many other enzymes. Wild-type Chinese hamster (Cricetulus griséus) ovary cells (CHO-K1) were treated with different doses of heparin. Heparanase expression was analyzed by Real-time PCR and flow cytometry. Also, heparanase activity was measured. The heparanase activity assay was performed using a coated plate with biotinylated heparan sulfate. In the present assay, a competitive heparin inhibition scenario was set aside. Exogenous heparin trigged a cell signaling pathway that increased heparanase mRNA and protein levels. The Wnt/beta-catenin pathway, judged by TCF-driven luciferase activity, seems to be involved to enhance heparanase profile during treatment with exogenous heparin. Lithium chloride treatment, an activator of the Wnt/beta-catenin pathway, confirmed such mechanism of transduction in vivo using zebrafish embryos and in vitro using CHO-K1 cells. Taken together the results suggest that heparin modulates heparanase expression by Wnt/beta-catenin.

Evaluation of the Toxicity of Intravenous Delivery of Auroshell Particles (Gold–Silica Nanoshells)

2012 ◽  
Vol 31 (6) ◽  
pp. 584-594 ◽  
Author(s):  
Shayne C. Gad ◽  
Kelly L. Sharp ◽  
Charles Montgomery ◽  
J. Donald Payne ◽  
Glenn P. Goodrich
Keyword(s):  
Water Solution ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Gold Nanoshells ◽  
Sprague Dawley ◽  
Ovary Cells ◽  
Good Laboratory ◽  
Chromosomal Aberration Assay

Gold nanoshells (155 nm in diameter with a coating of polyethylene glycol 5000) were evaluated for preclinical biocompatibility, toxicity, and biodistribution as part of a program to develop an injectable device for use in the photothermal ablation of tumors. The evaluation started with a complete good laboratory practice (GLP) compliant International Organization for Standardization (ISO)-10993 biocompatibility program, including cytotoxicity, pyrogenicity (US Pharmacopeia [USP] method in the rabbit), genotoxicity (bacterial mutagenicity, chromosomal aberration assay in Chinese hamster ovary cells, and in vivo mouse micronucleus), in vitro hemolysis, intracutaneous reactivity in the rabbit, sensitization (in the guinea pig maximization assay), and USP/ISO acute systemic toxicity in the mouse. There was no indication of toxicity in any of the studies. Subsequently, nanoshells were evaluated in vivo by intravenous (iv) infusion using a trehalose/water solution in a series of studies in mice, Sprague-Dawley rats, and Beagle dogs to assess toxicity for time durations of up to 404 days. Over the course of 14 GLP studies, the gold nanoshells were well tolerated and, when injected iv, no toxicities or bioincompatibilities were identified.

scholarly journals Properties of the kinetochore in vitro. I. Microtubule nucleation and tubulin binding.

1985 ◽  
Vol 101 (3) ◽  
pp. 755-765 ◽  
Author(s):  
T J Mitchison ◽  
M W Kirschner
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Lag Phase ◽  
Ovary Cells ◽  
Tubulin Binding ◽  
Mixed Polarity ◽  
Tubulin Immunofluorescence

We have isolated chromosomes from Chinese hamster ovary cells arrested in mitosis with vinblastine and examined the interactions of their kinetochores with purified tubulin in vitro. The kinetochores nucleate microtubule (MT) growth with complex kinetics. After an initial lag phase, MTs are continuously nucleated with both plus and minus ends distally localized. This mixed polarity seems inconsistent with the formation of an ordered, homopolar kinetochore fiber in vivo. As isolated from vinblastine-arrested cells, kinetochores contain no bound tubulin. The kinetochores of chromosomes isolated from colcemid-arrested cells or of chromosomes incubated with tubulin in vitro are brightly stained after anti-tubulin immunofluorescence. This bound tubulin is probably not in the form of MTs. It is localized to the corona region by immunoelectron microscopy, where it may play a role in MT nucleation in vitro.

scholarly journals The pericentriolar material in Chinese hamster ovary cells nucleates microtubule formation

1977 ◽  
Vol 73 (3) ◽  
pp. 601-615 ◽  
Author(s):  
RR Gould ◽  
GG Borisy
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Carbon Coated ◽  
Pericentriolar Material ◽  
And Function

The structure and function of the centrosomes from Chinese hamster ovary (CHO) cells were investigated by electron microscopy of negatively stained wholemount preparations of cell lysates. Cells were trypsinized from culture dishes, lysed with Triton X-100, sedimented onto ionized, carbon-coated grids, and negatively stained with phosphotungstate. The centrosomes from both interphase and dividing cells consisted of pairs of centrioles, a fibrous pericentriolar material, and a group of virus-like particles which were characteristic of the CHO cells and which served as markers for the pericentriolar material. Interphase centrosomes anchored up to two dozen microtubules when cells were lysed under conditions which preserved native microtubules. When Colcemid-blocked mitotic cells, initially devoid of microtubules, were allowed to recover for 10 min, microtubules formed at the pericentriolar material, but not at the centrioles. When lysates of Colcemid-blocked cells were incubated in vitro with micotubule protein purified from porcine brain tissue, up to 250 microtubules assembled at the centrosomes, similar to the number of microtubules that would normally form at the centrosome during cell division. A few microtubules could also be assembled in vitro onto the ends of isolated centrioles from which the pericentriolar material had been removed, forming characteristic axoneme- like bundles. In addition, microtubules; were assembled onto fragments of densely staining, fibrous material which was tentatively identified as periocentriolar material by its association of CHO can initiate and anchor microtubules both in vivo and in vitro.

scholarly journals Genetic alteration of endothelial heparan sulfate selectively inhibits tumor angiogenesis

2007 ◽  
Vol 177 (3) ◽  
pp. 539-549 ◽  
Author(s):  
Mark M. Fuster ◽  
Lianchun Wang ◽  
Janice Castagnola ◽  
Lyudmila Sikora ◽  
Krisanavane Reddi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heparan Sulfate ◽  
Tumor Angiogenesis ◽  
Wound Repair ◽  
Reproductive Capacity ◽  
Erk Phosphorylation ◽  
Tumor Endothelium ◽  
A Cell

To examine the role of endothelial heparan sulfate during angiogenesis, we generated mice bearing an endothelial-targeted deletion in the biosynthetic enzyme N-acetylglucosamine N-deacetylase/N-sulfotransferase 1 (Ndst1). Physiological angiogenesis during cutaneous wound repair was unaffected, as was growth and reproductive capacity of the mice. In contrast, pathological angiogenesis in experimental tumors was altered, resulting in smaller tumors and reduced microvascular density and branching. To simulate the angiogenic environment of the tumor, endothelial cells were isolated and propagated in vitro with proangiogenic growth factors. Binding of FGF-2 and VEGF164 to cells and to purified heparan sulfate was dramatically reduced. Mutant endothelial cells also exhibited altered sprouting responses to FGF-2 and VEGF164, reduced Erk phosphorylation, and an increase in apoptosis in branching assays. Corresponding changes in growth factor binding to tumor endothelium and apoptosis were also observed in vivo. These findings demonstrate a cell-autonomous effect of heparan sulfate on endothelial cell growth in the context of tumor angiogenesis.

Tie2 Activation Promotes Protection and Reconstitution of the Endothelial Glycocalyx in Human Sepsis

2019 ◽  
Vol 119 (11) ◽  
pp. 1827-1838 ◽  
Author(s):  
Carolin Christina Drost ◽  
Alexandros Rovas ◽  
Kristina Kusche-Vihrog ◽  
Paul Van Slyke ◽  
Harold Kim ◽  
...  
Keyword(s):  
Heparan Sulfate ◽  
Boundary Region ◽  
Endothelial Glycocalyx ◽  
Human Sepsis ◽  
Force Microscopy ◽  
Control Serum ◽  
A Cell ◽  
Angiopoietin 2

AbstractThe endothelial glycocalyx (eGC), a carbohydrate-rich layer lining the luminal surface of the endothelium, provides a first vasoprotective barrier against vascular leakage in sepsis. We hypothesized that angiopoietin-2 (Angpt-2), antagonist of the endothelium-stabilizing receptor Tie2, induces a rapid loss of the eGC in human sepsis. Using intravital microscopy, we measured the perfused boundary region (PBR), an inverse parameter of eGC dimensions in sublingual microvessels, in patients with sepsis and age-matched nonseptic subjects. Median PBR values were significantly higher in patients compared with controls and correlated with serum Angpt-2 levels. To transfer and further explore these findings in a cell culture system, we exposed endothelial cells (ECs) to serum (5%) from a subgroup of septic patients and nonseptic controls. Confocal and atomic force microscopy revealed that sepsis serum, but not control serum, induced thinning of the eGC on human ECs in vitro, which correlated with paired PBR values obtained in vivo (r = 0.96, p < 0.01). Inhibition of Angpt-2 or Tie2 activation completely abolished eGC damage. Mechanistically, sepsis-induced eGC breakdown required the loss of its main constituent heparan sulfate; a result of heparan sulfate-specific enzyme heparanase, which was suppressed by Tie2 activation. Finally, Tie2 activation, but not Angpt-2 inhibition, initiated after septic or enzymatic damage provoked rapid refurbishment of the eGC. Our data indicate that eGC breakdown in human sepsis is mediated via Tie2 deactivation by Angpt-2. Activation of Tie2 seems to accelerate recovery of the eGC and might hold promise as a therapeutic target in human sepsis.

scholarly journals Antithrombotic effect of recombinant human thrombomodulin on thrombin- induced thromboembolism in mice

Blood ◽  
1990 ◽  
Vol 75 (7) ◽  
pp. 1396-1399 ◽  
Author(s):  
K Gomi ◽  
M Zushi ◽  
G Honda ◽  
S Kawahara ◽  
O Matsuzaki ◽  
...  
Keyword(s):  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Lethal Effect ◽  
Dependent Manner ◽  
Antithrombotic Effect ◽  
Concentration Dependent Manner ◽  
Ovary Cells ◽  
Recombinant Thrombomodulin

Abstract Antithrombotic effect of recombinant human thrombomodulin in mice, both in vitro and in vivo, was studied. The soluble recombinant human thrombomodulin was expressed in Chinese hamster ovary cells and purified from the conditioned medium by a modification of the conventional method. Recombinant thrombomodulin prolonged thrombin clotting time for mouse plasma in a dose-dependent manner. Thrombin was injected into the lateral tail vein of mice and caused acute thromboembolism. All mice injected with thrombin died of thromboembolism; however, preinjection with recombinant human thrombomodulin neutralized the lethal effect of thrombin in a concentration-dependent manner. Histologic examination showed that fibrin deposits were found in all large and small arteries in the lung from mice injected with thrombin; however, fibrin deposits were not detected in any large arteries from the mouse preinjected with thrombomodulin.

Mutagenic Activity of p-Toluenesulfonhydrazide

1992 ◽  
Vol 8 (6) ◽  
pp. 369-376 ◽  
Author(s):  
David H. Blakey ◽  
Earle R. Nestmann ◽  
Janet M. Bayley ◽  
K. Laurie Maus ◽  
George R. Douglas
Keyword(s):  
Chinese Hamster Ovary ◽  
Mutagenic Activity ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Gene Mutations ◽  
Metabolic Activation ◽  
High Volume ◽  
Ovary Cells

Toluenesulfonhydrazide (TSH) is a high volume production chemical for which there is relatively little toxicological data. In this study, the mutagenic activity of TSH was determined in the Salmonella/mammalian microsome assay and the in vitro chromosomal aberration assay using Chinese hamster ovary cells. TSH induced gene mutations both with and without metabolic activation in the Salmonella/mammalian microsome assay but that it did not induce chromosomal aberrations in Chinese hamster ovary cells. The results of this study indicate that TSH is an in vitro mutagen and should be assessed for in vivo mutagenicity.

scholarly journals Three regulatory compliant test systems show no signs of MDMA-related genotoxicity

2021 ◽  
pp. 026988112110336
Author(s):  
Isaac Victor Cohen ◽  
Laken Barber ◽  
Tyson Paul Dubnicka ◽  
Sara Beth Hurtado ◽  
Sarah Ann Tincher ◽  
...  
Keyword(s):  
Stress Disorder ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Sprague Dawley ◽  
Genotoxic Effects ◽  
Ovary Cells ◽  
Sprague Dawley Rats ◽  
Chromosome Aberration Test

3,4 Methylenedioxymethamphetamine (MDMA)-assisted therapy has been recently found to be highly effective for treatment of posttraumatic stress disorder (PTSD). Previous studies have been inconclusive in elucidating potential MDMA genotoxicity. We performed three regulatory compliant studies to investigate the potential of genotoxic effects of MDMA treatment in humans: (1) an in vitro bacterial reverse mutation (Ames) assay, (2) an in vitro chromosome aberration test in Chinese hamster ovary cells, and (3) an in vivo micronucleus study in male Sprague Dawley rats. MDMA was found to not have genotoxic effects in any of the assays at or above clinically relevant concentrations.

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