Enzyme Increase by Folate and Methotrexate in Cultured Mammalian Cells

1974 ◽  
Vol 52 (12) ◽  
pp. 1132-1136
Author(s):  
B. L. Hillcoat ◽  
L. Marshall
Keyword(s):  
Enzyme Activity ◽  
Cell Lines ◽  
Dihydrofolate Reductase ◽  
Somatic Hybrid ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Enzyme Synthesis ◽  
Intracellular Concentration ◽  
Parent Cell ◽  
Human Origin

Folate and methotrexate markedly increased the activity of dihydrofolate reductase in cultured cells of human origin. Folate did not have this effect in the cells of other species tested, whereas methotrexate increased enzyme activity in some other species. Neither compound increased enzyme activity in a somatic hybrid, although such an increase occurred in one of the parent cell lines. Active enzyme synthesis appeared necessary for the effect of folate to occur. Degradation of the increased enzyme after cycloheximide treatment of cells proceeded at least as rapidly as in control cultures and was associated with a decrease in the intracellular folate pool, whereas folate added after 48 h of culture stabilized the enzyme at this same intracellular concentration. Folate, added at 24 h of culture, produced the greatest increase in activity, but the subsequent rate of decrease was greater than that when folate was added at 48 h, although the intracellular concentration of folate in the latter case was only half that in the former.

scholarly journals Expression of small cytoplasmic transcripts of the rat identifier element in vivo and in cultured cells.

1987 ◽  
Vol 7 (6) ◽  
pp. 2148-2154 ◽  
Author(s):  
R D McKinnon ◽  
P Danielson ◽  
M A Brow ◽  
F E Bloom ◽  
J G Sutcliffe
Keyword(s):  
Rat Brain ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Culture Conditions ◽  
Specific Expression ◽  
Peripheral Tissues ◽  
Primate Cell

We examined the level of expression of small RNA transcripts hybridizing to a rodent repetitive DNA element, the identifier (ID) sequence, in a variety of cell types in vivo and in cultured mammalian cells. A 160-nucleotide (160n) cytoplasmic poly(A)+ RNA (BC1) appeared in late embryonic and early postnatal rat brain development, was enriched in the cerebral cortex, and appeared to be restricted to neural tissue and the anterior pituitary gland. A 110n RNA (BC2) was specifically enriched in brain, especially the postnatal cortex, but was detectable at low levels in peripheral tissues. A third, related 75n poly(A)- RNA (T3) was found in rat brain and at lower levels in peripheral tissues but was very abundant in the testes. The BC RNAs were found in a variety of rat cell lines, and their level of expression was dependent upon cell culture conditions. A rat ID probe detected BC-like RNAs in mouse brain but not liver and detected a 200n RNA in monkey brain but not liver at lower hybridization stringencies. These RNAs were expressed by mouse and primate cell lines. Thus, tissue-specific expression of small ID-sequence-related transcripts is conserved among mammals, but the tight regulation found in vivo is lost by cells in culture.

scholarly journals Stress induction of the spermidine/spermine N1-acetyltransferase by a post-transcriptional mechanism in mammalian cells

1993 ◽  
Vol 294 (2) ◽  
pp. 491-495 ◽  
Author(s):  
E W Gerner ◽  
T A Kurtts ◽  
D J M Fuller ◽  
R A Casero
Keyword(s):  
Enzyme Activity ◽  
Mammalian Cells ◽  
Human Origin ◽  
Animal Cells ◽  
Stress Induction ◽  
Steady State Levels ◽  
Amine Groups ◽  
Spermidine Analogues ◽  
Exogenous Spermidine ◽  
Ssat Activity

Heat shock and diethyldithiocarbamate stimulate polyamine catabolism in animal cells by a mechanism involving the induction of spermidine/spermine N1-acetyltransferase (N1-SSAT) activity. Steady-state levels of RNA encoding this enzyme remain essentially unchanged during periods after these stresses when N1-SSAT activity is increased by 3.5-10-fold or more in three different cell lines of hamster and human origin. Depletion of intracellular spermidine pools by alpha-difluoromethylornithine (DFMO) inhibits stress induction of N1-SSAT activity. Exogenous spermidine can restore stress inducibility of N1-SSAT to DFMO-treated cells, and induce this enzyme activity in non-heat-shocked but polyamine-depleted cells. Acetylation at N1 suppresses the ability of spermidine to induce N1-SSAT activity, relative to this same modification at N8. Fluorinated spermidine analogues, which decrease the pKa values of the amine groups at positions 4 and 8, neither induce nor inhibit N1-SSAT activity in DFMO-treated cells. These data demonstrate that certain stresses induce N1-SSAT by a spermidine-dependent post-transcriptional mechanism. The mode of induction is affected by both the propyl and butyl moieties of spermidine.

scholarly journals TEMPORAL ORDER IN MAMMALIAN CELLS

1969 ◽  
Vol 43 (2) ◽  
pp. 207-219 ◽  
Author(s):  
Robert R. Klevecz
Keyword(s):  
Enzyme Activity ◽  
Mammalian Cells ◽  
Temporal Order ◽  
Actinomycin D ◽  
Chinese Hamster ◽  
Enzyme Synthesis ◽  
S Phase ◽  
Selection System ◽  
Enzyme Protein ◽  
Chinese Hamster Cells

Chinese hamster cells were synchronized by the Colcemid-selection system. In cells with a division cycle time of 11.5–12 hr, the activity of the enzyme lactate dehydrogenase (LDH) underwent marked oscillations with a 3.5-hr period. Precipitation of labeled LDH enzyme with specific antibody indicated that the enzyme activity changes were the result of intermittent enzyme synthesis and relatively constant degradation. Inhibition of normal DNA replication with 4 mM of thymidine, while reducing the amount of new enzyme synthesized, did not prevent oscillations from occurring. Similarly, actinomycin D (AcD) added at the time of synchronization allowed some new enzyme synthesis to proceed in an oscillatory manner. LDH synthesis went on at nearly normal rates when AcD was added in the middle of S phase. However, addition of cycloheximide to cultures at any time in the cycle caused an immediate drop in levels of activity and in enzyme protein. The half-life of LDH, calculated either from loss of enzyme activity or precipitable radioactivity in cycloheximide-treated cultures, was between 2 and 2.5 hr.

Expression of small cytoplasmic transcripts of the rat identifier element in vivo and in cultured cells

1987 ◽  
Vol 7 (6) ◽  
pp. 2148-2154
Author(s):  
R D McKinnon ◽  
P Danielson ◽  
M A Brow ◽  
F E Bloom ◽  
J G Sutcliffe
Keyword(s):  
Rat Brain ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Cell Types ◽  
Culture Conditions ◽  
Specific Expression ◽  
Peripheral Tissues ◽  
Primate Cell

We examined the level of expression of small RNA transcripts hybridizing to a rodent repetitive DNA element, the identifier (ID) sequence, in a variety of cell types in vivo and in cultured mammalian cells. A 160-nucleotide (160n) cytoplasmic poly(A)+ RNA (BC1) appeared in late embryonic and early postnatal rat brain development, was enriched in the cerebral cortex, and appeared to be restricted to neural tissue and the anterior pituitary gland. A 110n RNA (BC2) was specifically enriched in brain, especially the postnatal cortex, but was detectable at low levels in peripheral tissues. A third, related 75n poly(A)- RNA (T3) was found in rat brain and at lower levels in peripheral tissues but was very abundant in the testes. The BC RNAs were found in a variety of rat cell lines, and their level of expression was dependent upon cell culture conditions. A rat ID probe detected BC-like RNAs in mouse brain but not liver and detected a 200n RNA in monkey brain but not liver at lower hybridization stringencies. These RNAs were expressed by mouse and primate cell lines. Thus, tissue-specific expression of small ID-sequence-related transcripts is conserved among mammals, but the tight regulation found in vivo is lost by cells in culture.

scholarly journals Regulation of protein accumulation in cultured cells

1982 ◽  
Vol 208 (2) ◽  
pp. 275-287 ◽  
Author(s):  
F J Ballard
Keyword(s):  
Protein Synthesis ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Calf Serum ◽  
Protein Accumulation ◽  
Foetal Calf Serum ◽  
Protein Breakdown ◽  
Breakdown Rates ◽  
Human Breast Carcinoma Cells

1. A technique is described whereby protein synthesis, protein breakdown and net protein accumulation are measured separately in monolayer cultures of mammalian cells. All rates are expressed as microgram of protein per 18 h incubation. 2. Under most incubation conditions with either L6 rat myoblasts or T47D human breast carcinoma cells the rates of protein accumulation, determined directly, agreed with the rates obtained by subtracting protein breakdown from protein synthesis. 3. Foetal calf serum, human and bovine colostrum, human milk and insulin increased protein accumulation in both cell lines, mainly as a consequence of effects on protein synthesis. 4. NH4Cl, in addition to inhibiting protein breakdown in both cell lines in the presence and in the absence of serum, stimulated protein synthesis in L6 myoblasts. 5. Leupeptin slightly inhibited protein breakdown without affecting protein-synthesis rates. 6. Cycloheximide almost completely inhibited protein synthesis, but restricted the net loss of cell proteins under most conditions because protein-breakdown rates were also decreased. 7. The assumptions, limitations and potential application of this technique for evaluating changes in protein turnover are described.

scholarly journals Purification and properties of dihydrofolate reductase from cultured mammalian cells

1973 ◽  
Vol 133 (2) ◽  
pp. 349-356 ◽  
Author(s):  
J. Gauldie ◽  
L. Marshall ◽  
B. L. Hillcoat
Keyword(s):  
Enzyme Activity ◽  
Affinity Chromatography ◽  
Dihydrofolate Reductase ◽  
Gel Electrophoresis ◽  
Mammalian Cells ◽  
Buffer Concentration ◽  
Purification And Properties ◽  
Enzyme Stimulation ◽  
A Charge ◽  
Stimulation Of

Dihydrofolate reductase was purified quickly and simply from small quantities of cultured mammalian cells by affinity chromatography. On gel electrophoresis of the purified enzyme, multiple bands of activity resulted from enzyme–buffer interaction at low but not high buffer concentration. A Ferguson plot (Ferguson, 1964) showed that this heterogeneity was due to a charge difference with no alteration in the size of the enzyme. Stimulation of enzyme activity by KCl, urea and p-hydroxymercuribenzoate, and inhibition by methotrexate and trimethoprim, showed only minor differences between the various enzymes.

Macrophage Inhibition of Collagen-Induced Platelet Aggregation

1979 ◽  
Vol 42 (04) ◽  
pp. 1207-1216 ◽  
Author(s):  
Berit Mørland
Keyword(s):  
Enzyme Activity ◽  
Platelet Aggregation ◽  
Peritoneal Macrophage ◽  
Cultured Cells ◽  
Culture Media ◽  
Human Platelets ◽  
Mouse Peritoneal Macrophage ◽  
Collagenase Activity ◽  
Partial Inhibition ◽  
Macrophage Phagocytosis

SummaryCollagen was incubated with cells or media fractions of mouse peritoneal macrophage cultures, and its aggregating effect on human platelets was tested. Incubation with lysates of cultured cells completely abolished the normal collagen-induced platelet aggregation, while incubation with media fractions only caused partial inhibition. The latter inhibition was more pronounced after macrophage phagocytosis of latex particles, while endocytosis of endotoxin had no effect.Corresponding macrophage cultures were also tested for specific collagenase activity, using 14C-glycine labelled collagen as substrate. Collagenase activity was found in the culture media fractions only, and the enzyme activity could be enhanced by endocytosis of latex as well as endotoxin.It appears that the effect of macrophage lysates and media on collagen-platelet interaction cannot be ascribed only to secretion of collagenase from macrophages.

Characterization of Healthy and Tumor Oral Cell Lines of Human Origin. The preliminary stage in the assessment of relevant chemical compounds with impact on dentistry

2018 ◽  
Vol 69 (10) ◽  
pp. 2889-2894
Author(s):  
Ion Virgil Corlan ◽  
Adelina Cheveresan ◽  
Delia Berceanu Vaduva ◽  
Cristian Nica ◽  
Alin Faur ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Cell Lines ◽  
Squamous Cell ◽  
Chemical Compounds ◽  
Tongue Squamous Cell Carcinoma ◽  
Gingival Fibroblasts ◽  
Human Origin ◽  
Preliminary Stage

The present study was aimed to evaluate the confluence percentage of three oral cell lines, namely primary gingival keratinocytes (PGK), primary gingival fibroblasts (HGF) and tongue squamous cell carcinoma (SCC-4). All cells have been monitored at different passages for 21 days. Evaluation of confluence percentage reveals the fact that primary gingival keratinocytes and tongue squamous cell carcinoma at small passages requires a period of about two weeks to reach a confluence of approximately 80% while for the gingival fibroblasts a period of about three times smaller is satisfactory.

Synthesis, cytotoxicity, antioxidant and antimicrobial activity of indole based novel small molecule

2020 ◽  
Vol 17 ◽  
Author(s):  
Aslıhan Kurt-Kızıldoğan ◽  
Çiğdem Otur ◽  
Can Yılmaz ◽  
Sevki Arslan ◽  
Dogukan Mutlu ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cytotoxic Effect ◽  
Antimicrobial Properties ◽  
Cancer Cell Lines ◽  
Coupling Reactions ◽  
Human Liver Cancer ◽  
Glutathione S Transferases ◽  
Antioxidant And Antimicrobial Activity

Background:: Indoles probably represent one of the most important heterocyclic structures that have been attracting the interest of many scientists in drug discovery. Methods:: Pd-catalyst Sonogashira coupling reactions, MTT Assay, Antioxidant capacity test, Antimicrobial test, GST enzyme activity test. Results and Discussion:: 1-ethyl-2-phenyl-3-(phenylethynyl)-1H-indole had antioxidant and antimicrobial properties. It displayed significant induction in glutathione S-transferases (GST) enzyme activity in human liver cancer cell lines (HepG2), but cytotoxic effect on all tested cancer cell lines could not be observed. Conclusion:: All of these results showed that 1-ethyl-2-phenyl-3-(phenylethynyl)-1H-indole had antioxidant and antimicrobial properties without cytotoxic effect, which could make it a promising active component.

scholarly journals Itaconate Alters Succinate and Coenzyme A Metabolism via Inhibition of Mitochondrial Complex II and Methylmalonyl-CoA Mutase

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Thekla Cordes ◽  
Christian M. Metallo
Keyword(s):  
Amino Acid ◽  
Metabolic Pathways ◽  
Mammalian Cells ◽  
Coenzyme A ◽  
Cultured Cells ◽  
Tca Cycle ◽  
Regulatory Function ◽  
Reversible Inhibitor ◽  
Complex Ii ◽  
Branched Chain

Itaconate is a small molecule metabolite that is endogenously produced by cis-aconitate decarboxylase-1 (ACOD1) in mammalian cells and influences numerous cellular processes. The metabolic consequences of itaconate in cells are diverse and contribute to its regulatory function. Here, we have applied isotope tracing and mass spectrometry approaches to explore how itaconate impacts various metabolic pathways in cultured cells. Itaconate is a competitive and reversible inhibitor of Complex II/succinate dehydrogenase (SDH) that alters tricarboxylic acid (TCA) cycle metabolism leading to succinate accumulation. Upon activation with coenzyme A (CoA), itaconyl-CoA inhibits adenosylcobalamin-mediated methylmalonyl-CoA (MUT) activity and, thus, indirectly impacts branched-chain amino acid (BCAA) metabolism and fatty acid diversity. Itaconate, therefore, alters the balance of CoA species in mitochondria through its impacts on TCA, amino acid, vitamin B12, and CoA metabolism. Our results highlight the diverse metabolic pathways regulated by itaconate and provide a roadmap to link these metabolites to potential downstream biological functions.

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