Effects of 2, 3-iminosqualene on cultured cells

1987 ◽  
Vol 232 (1268) ◽  
pp. 273-287 ◽  
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Medium ◽  
Chronic Treatment ◽  
Cultured Cells ◽  
Culture Media ◽  
Chinese Hamster ◽  
Metabolic Processes ◽  
The Media ◽  
Rat Hepatoma

2, 3-Iminosqualene (ISq) is a powerful inhibitor of squalene oxide: lanosterol cyclase (EC 5.4.99.7). When added to lipid-depleted culture media (LDM) of rat hepatoma (H-4-II-E-C3) or Chinese hamster ovary (CHO) cells at a concentration of 10 μg ml -1 , it causes the cells to float off the substratum in a few days. Lipoproteins in the culture medium completely counteract this effect. Cells in lipoprotein-containing media (FGM) grow normally in the presence of ISq. Irrespective of the culture medium, ISq at 10 μg ml -1 causes an almost complete and apparently irreversible inactivation of the squalene oxide cyclase in CHO and H4 cells and the accumulation in the cells of squalene, of squalene 2, 3-oxide (mostly), and of squalene 2, 3-22, 23-dioxide when [ 14 C]acetate or [ 14 C]mevalonate is fed to the cells. Chronic treatment of H4 cells with ISq failed to elicit induction of the cyclase, but increased the conversion of mevalonate into squalene and squalene dioxide, and depressed the conversion of squalene oxide to the dioxide. Cells loaded with squalene and the squalene oxides from mevalonate in the presence of ISq get rid of these substances by rapidly secreting them into the media and by some unidentified metabolic processes.

scholarly journals Assay method for Vibrio cholerae and Escherichia coli enterotoxins by automated counting of floating chinese hamster ovary cells in culture medium

1978 ◽  
Vol 7 (5) ◽  
pp. 479-485
Author(s):  
R T Nozawa ◽  
T Yokota ◽  
S Kuwahara
Keyword(s):  
Escherichia Coli ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Medium ◽  
Culture Media ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Assay Method ◽  
Ovary Cells ◽  
E Coli

As Chinese hamster ovary (CHO) cells on plastic proliferate, many cells float off into the medium instead of piling up after they form a monolayer. Fewer cells were floating in the medium when CHO cells were incubated with cholera toxin at a concentration as low as 10 pg/ml. The toxin increased the adhesiveness of the cells forming confluent monolayers so that the floating cells accumulated on the adherent monolayers. On the basis of this finding, a simple, quantitative assay method for cholera and Escherichia coli enterotoxins was devised by cultivating CHO cells in a Linbro multidish and counting the cells in the medium with a Coulter Counter. The method was sensitive enough to detect toxins in 100- to 200-fold-diluted culture media of toxigenic E. coli strains. Little or no activity was detected by this method in the culture medium of nontoxigenic E. coli.

scholarly journals Hydrophobic glycosides of N-acetylglucosamine can act as primers for polylactosamine synthesis and can affect glycolipid synthesis in vivo

1995 ◽  
Vol 307 (3) ◽  
pp. 791-797 ◽  
Author(s):  
D C A Neville ◽  
R A Field ◽  
M A J Ferguson
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Medium ◽  
Linear Array ◽  
Chinese Hamster ◽  
Living Cells ◽  
Anomeric Configuration ◽  
Glycolipid Synthesis ◽  
Synthetic Capacity

Several hydrophobic glycosides of N-acetylglucosamine (GlcNAc) served as primers for polylactosamine synthesis when added to Chinese hamster ovary (CHO) cells. The modified glycosides, containing one to six lactosamine repeats in linear array, were sialylated and secreted into the culture medium. The relative efficiencies of the glycosides to serve as primers were dependent on the nature of the aglycone and on the anomeric configuration of the GlcNAc residue. The same compounds were tested for their effects on glycolipid synthesis in CHO cells. All of the beta-glycosides significantly inhibited the synthesis of the lactoseries glycolipid GM3 whereas the alpha-glycoside was inactive. The compound GlcNAc alpha 1-O-benzyl- was the most efficient primer of polylactosamine synthesis and had no effect on glycolipid synthesis. This compound may have potential for the assay of the polylactosamine synthetic capacity of living cells.

Cloning of cDNA for goldfish activin βB subunit, and the expression of its mRNA in gonadal and non-gonadal tissues

1997 ◽  
Vol 19 (1) ◽  
pp. 37-45 ◽  
Author(s):  
W Ge ◽  
T Miura ◽  
H Kobayashi ◽  
R E Peter ◽  
Y Nagahama
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Medium ◽  
Specific Activity ◽  
Chinese Hamster ◽  
Amino Acid Identity ◽  
Acid Identity ◽  
Wide Range

ABSTRACT We have cloned a full length cDNA coding for activin βB subunit from the goldfish ovary. Sequence analysis of the goldfish activin βB shows that this peptide is extremely conserved across vertebrates. The mature region of goldfish activin βB has 93 and 98% amino acid identity with that of human and zebrafish βB subunit respectively. The identity of the cloned goldfish activin βB was further confirmed by expressing the protein in the Chinese hamster ovary (CHO) cells followed by detection of the specific activity of activin in the culture medium using F5-5 cell assay. mRNA of goldfish activin βB is expressed in a variety of goldfish tissues including ovary, testis, brain, pituitary, kidney and liver, suggesting a wide range of physiological roles for activin in the goldfish.

Congenital hypofibrinogenemia associated with γK232T

2018 ◽  
Vol 38 (01) ◽  
pp. 43-48 ◽  
Author(s):  
Zhao Misheng ◽  
Wang Mingshan ◽  
Lou Zhefeng ◽  
Chen Xiaoli ◽  
Yu Dandan ◽  
...  
Keyword(s):  
Western Blot ◽  
Cho Cells ◽  
Molecular Basis ◽  
Culture Medium ◽  
Culture Media ◽  
Chinese Hamster ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Congenital Hypofibrinogenemia

SummaryWe have previously reported a case of congenital hypofibrinogenemia caused by a novel heterozygous A→C transition at nucleotide 5864 of FGG, leading to the K232T substitution in the fibrinogen γ-chain. However, the pathogenic mechanism is still unclear. To further reveal its molecular basis, we examined the effects of γK232T substitution on fibrinogen synthesis, stability, and secretion through in vitro expression of mutant γ232T in Chinese hamster ovary (CHO) cells. Quantitative RT-PCR of the variant γ-chain mRNA showed that the γ232T transcribed the variant cDNA. Enzyme-linked immunosorbent assay and Western blot analysis of the cell lysates and culture media showed that the CHO cells transfected with successfully synthesized the variant fibrinogen, but failed to secrete it into the culture medium. Furthermore, fibrinogen purified from the plasma of patient showed a normal thrombin-catalyzed fibrin polymerization, also indicating the impeding secretion of variant γ232T fibrinogen. In conclusion, our data reveal that the γK232T is responsible for the congenital hypofibrinogenaemia through interfering with the correct secretion of fibrinogen.

Insulin degrading enzyme (IDE) expressed by Chinese hamster ovary (CHO) cells is responsible for degradation of insulin in culture media

2020 ◽  
Vol 320 ◽  
pp. 44-49
Author(s):  
Salina Louie ◽  
Jayanthi Lakkyreddy ◽  
Brian M. Castellano ◽  
Benjamin Haley ◽  
Anh Nguyen Dang ◽  
...  
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Culture Media ◽  
Chinese Hamster ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme

Review of the current methods of Chinese Hamster Ovary (CHO) cells cultivation for production of therapeutic protein

2020 ◽  
Vol 17 ◽  
Author(s):  
Shazid Md. Sharker ◽  
Md. Atiqur Rahman
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Mass Production ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Therapeutic Protein ◽  
Specific Productivity ◽  
Ovary Cells ◽  
Further Development ◽  
Interesting Area

Most of clinical approved protein-based drugs or under in clinical trial have a profound impact in the treatment of critical diseases. The mammalian eukaryotic cells culture approaches, particularly the CHO (Chinese Hamster Ovary) cells are mainly used in the biopharmaceutical industry for the mass-production of therapeutic protein. Recent advances in CHO cell bioprocessing to yield recombinant proteins and monoclonal antibodies have enabled the expression of quality protein. The developments of cell lines are possible to upgrade specific productivity. As a result, it holds an interesting area for academic as well as industrial researchers around the world. This review will concentrate on the recent progress of the mammalian CHO cells culture technology and the future scope of further development for the mass-production of protein therapeutics.

scholarly journals Recombinant γY278H Fibrinogen Showed Normal Secretion from CHO Cells, but a Corresponding Heterozygous Patient Showed Hypofibrinogenemia

2021 ◽  
Vol 22 (10) ◽  
pp. 5218
Author(s):  
Tomu Kamijo ◽  
Takahiro Kaido ◽  
Masahiro Yoda ◽  
Shinpei Arai ◽  
Kazuyoshi Yamauchi ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cho Cells ◽  
Fibrinogen Level ◽  
Culture Media ◽  
Chinese Hamster ◽  
Plasma Fibrinogen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cho Cell ◽  
Accelerated Degradation ◽  
Heterozygous Patient

We identified a novel heterozygous hypofibrinogenemia, γY278H (Hiroshima). To demonstrate the cause of reduced plasma fibrinogen levels (functional level: 1.12 g/L and antigenic level: 1.16 g/L), we established γY278H fibrinogen-producing Chinese hamster ovary (CHO) cells. An enzyme-linked immunosorbent assay demonstrated that synthesis of γY278H fibrinogen inside CHO cells and secretion into the culture media were not reduced. Then, we established an additional five variant fibrinogen-producing CHO cell lines (γL276P, γT277P, γT277R, γA279D, and γY280C) and conducted further investigations. We have already established 33 γ-module variant fibrinogen-producing CHO cell lines, including 6 cell lines in this study, but only the γY278H and γT277R cell lines showed disagreement, namely, recombinant fibrinogen production was not reduced but the patients’ plasma fibrinogen level was reduced. Finally, we performed fibrinogen degradation assays and demonstrated that the γY278H and γT277R fibrinogens were easily cleaved by plasmin whereas their polymerization in the presence of Ca2+ and “D:D” interaction was normal. In conclusion, our investigation suggested that patient γY278H showed hypofibrinogenemia because γY278H fibrinogen was secreted normally from the patient’s hepatocytes but then underwent accelerated degradation by plasmin in the circulation.

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