Search results for "Chinese hamster ovary cell"
showing 10 items of 41 documents
Transient Multivalent Nanobody Targeting to CD206-Expressing Cells via PH-Degradable Nanogels
2020
To target nanomedicines to specific cells, especially of the immune system, nanobodies can be considered as an attractive tool, as they lack the Fc part as compared to traditional antibodies and, thus, prevent unfavorable Fc-receptor mediated mistargeting. For that purpose, we have site-specifically conjugated CD206/MMR-targeting nanobodies to three types of dye-labeled nanogel derivatives: non-degradable nanogels, acid-degradable nanogels (with ketal crosslinks), and single polymer chains (also obtained after nanogel degradation). All of them can be obtained from the same reactive ester precursor block copolymer. After incubation with naï
Agonist‐induced desensitisation of β 3 ‐adrenoceptors: Where, when, and how?
2019
β3 -Adrenoceptor agonists have proven useful in the treatment of overactive bladder syndrome, but it is not known whether their efficacy during chronic administration may be limited by receptor-induced desensitisation. Whereas the β2 -adrenoceptor has phosphorylation sites that are important for desensitisation, the β3 -adrenoceptor lacks these; therefore, it had been assumed that β3 -adrenoceptors are largely resistant to agonist-induced desensitisation. While all direct comparative studies demonstrate that β3 -adrenoceptors are less susceptible to desensitisation than β2 -adrenoceptors, desensitisation of β3 -adrenoceptors has been observed in many models and treatment settings. Chimeric …
Mechanisms of beauvericin toxicity and antioxidant cellular defense
2015
Beauvericin (BEA) is a secondary metabolite produced by many species of fungus Fusarium. This study determines the injury (cell viability, cell proliferation, mitochondrial membrane potential, cell death and DNA damage) and the intracellular defense mechanisms (catalase and superoxide dismutase) in Chinese Hamster ovary (CHO-K1) cells after BEA exposure. The results obtained in this study demonstrated that BEA induces cytotoxicity in a dose- and time-dependent manner in CHO-K1 cells. Moreover, disruption in mitochondrial enzymatic activity and cell proliferation has been observed after BEA exposure, which can lead or be consequence of cell death. BEA inhibits cell proliferation by arresting…
Intestinal CD36. A lipid-sensor involved in the processing of chylomicrons in rodents
2011
International audience; CD36 is a multifunctional glycoprotein which binds nanomolar concentrations of long-chain fatty acids (LCFA) and is highly expressed on the luminal surface of enterocytes. Despite of its implication in oleoylethanolamide (OEA) and chylomicron synthesis, CD36 function in small intestine remains incompletely understood. Our in vivo data demonstrated that CD36 gene deletion in mice did not affect intestinal LCFA uptake. CD36 protein disappeared early from the luminal side of intestinal villi during the post-prandial period but only when the diet contained lipids. This drop was significant 1 h after a lipid supply and was associated with ubiquitination of CD36. Using CHO…
Prevalence and clinical relevance of thyroid stimulating hormone receptor-blocking antibodies in autoimmune thyroid disease
2017
Summary The prevalence and clinical relevance of thyroid stimulating hormone (TSH) receptor (TSHR) blocking antibodies (TBAb) in patients with autoimmune thyroid disease (AITD) was investigated. Serum TBAb were measured with a reporter gene bioassay using Chinese hamster ovary cells. Blocking activity was defined as percentage inhibition of luciferase expression relative to induction with bovine TSH alone (cut-off 40% inhibition). All samples were measured for TSHR stimulatory antibody (TSAb) and TSHR binding inhibiting immunoglobulins (TBII). A total of 1079 unselected, consecutive patients with AITD and 302 healthy controls were included. All unselected controls were negative for TBAb and…
Selection and characterization of a novel agonistic human recombinant anti-Trail-R2 minibody with anti-leukemic activity
2009
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising natural anticancer therapeutic agent because through its “death receptors”, TRAIL-R1 and TRAIL-R2, it induces apoptosis in many transformed tumor cells, but not in the majority of normal cells. Hence, agonistic compounds directed against TRAIL death receptors have the potential of being excellent cancer therapeutic agents, with minimal cytotoxicity in normal tissues. Here, we report the selection and characterization of a new single-chain fragment variable (scFv) to TRAIL-R2 receptor isolated from a human phage-display library, produced as minibody (MB), and characterized for the in vitro anti-leukemic tumoricid…
Mismatch G-T binding activity and MSH2 expression is quantitatively related to sensitivity of cells to methylating agents
1998
To elucidate mechanisms involved in alkylating drug resistance, Chinese hamster cells resistant to methylating agents have been generated upon transfection with human DNA. Here it is shown that these Chinese hamster ovary (CHO) variants exhibit the tolerance phenotype: they are alkyltransferase deficient (Mex-), cross-resistant to 6-thioguanine, exhibit reduced G-T binding (MutS alpha) activity and express the mismatch repair protein MSH2 at a significantly lower level than the corresponding control. By comparing wild-type cells with different tolerant strains that show gradual differences in resistance to methylating agents, it was shown that both the G-T binding activity and the amount of…
Hypertonic Stress and Amino Acid Deprivation Both Increase Expression of mRNA for Amino Acid Transport System A
2004
The activity of amino acid transport system A ([Oxender and Christensen, 1963][1]) is regulated in a variety of different ways, the best studied being the increases of its activity caused by starving cells of amino acids or by exposing them to hypertonicity (for review see [McGivan and Pastor-
Effect of polyphenols on enniatins-induced cytotoxic effects in mammalian cells
2012
Enniatins (ENs) are fungal secondary metabolites produced by genus Fusarium. The ENs exert antimicrobial and insecticidal effect, and has also been demonstrated cytotoxic effects on several mammalian cell lines. On the other hands, it has been proved that natural polyphenols have antioxidant effect. In this study, cell effects at low levels of exposure of four ENs (A, A(1), B and B(1)) and five polyphenols (quercetin, quercetin-3-β-D-glucoside, rutin, myricetin and t-pterostilbene) present in wine; and the cytoprotective effect of these polyphenols exposed simultaneously with ENs in Chinese Hamster Ovary (CHO-K1) cells, were studied. Cell effects were determined by the MTT test after 24 h o…
Overexpression of Ogg1 in mammalian cells: effects on induced and spontaneous oxidative DNA damage and mutagenesis
1999
Chinese hamster ovary cell lines (AA8 and AS52) were stably transfected to overexpress hOgg1 protein, the human DNA repair glycosylase for 7,8-dihydro-8-oxoguanine (8-oxoG). In the transfectants, the repair rate of 8-oxoG residues induced by either potassium bromate or the photosensitizer [R]-1-[(10-chloro-4-oxo-3-phenyl-4H-benzo[a]quinolizin-1-yl)-carbo nyl ]-2-pyrrolidinemethanolplus light was up to 3-fold more rapid than in the parental cells. However, the improved repair had little effect on the mutagenicity of potassium bromate in the guanine phosphoribosyl transferase (gpt) locus of the OGG1-transfected AS52 cells. The steady-state (background) levels of DNA base modifications sensiti…