Mitotic segregation of cytoplasmic determinants for chloramphenicol resistance in mammalian cells I: Fusions with mouse cell lines

1977 ◽  
Vol 3 (1) ◽  
pp. 71-92 ◽  
Author(s):  
C. L. Bunn ◽  
D. C. Wallace ◽  
J. M. Eisenstadt
2021 ◽  
Vol 11 (6) ◽  
pp. 2534
Author(s):  
Henrike Rebl ◽  
Claudia Bergemann ◽  
Sebastian Rakers ◽  
Barbara Nebe ◽  
Alexander Rebl

The present study provides the fundamental results for the treatment of marine organisms with cold atmospheric pressure plasma. In farmed fish, skin lesions may occur as a result of intensive fish farming. Cold atmospheric plasma offers promising medical potential in wound healing processes. Since the underlying plasma-mediated mechanisms at the physical and cellular level are yet to be fully understood, we investigated the sensitivity of three fish cell lines to plasma treatment in comparison with mammalian cells. We varied (I) cell density, (II) culture medium, and (III) pyruvate concentration in the medium as experimental parameters. Depending on the experimental setup, the plasma treatment affected the viability of the different cell lines to varying degrees. We conclude that it is mandatory to use similar cell densities and an identical medium, or at least a medium with identical antioxidant capacity, when studying plasma effects on different cell lines. Altogether, fish cells showed a higher sensitivity towards plasma treatment than mammalian cells in most of our setups. These results should increase the understanding of the future treatment of fish.


Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 3050-3059 ◽  
Author(s):  
J Castrop ◽  
D van Wichen ◽  
M Koomans-Bitter ◽  
M van de Wetering ◽  
R de Weger ◽  
...  

Abstract The TCF-1 gene encodes a putative transcription factor with affinity for a sequence motif occurring in a number of T-cell enhancers. TCF-1 mRNA was originally found to be expressed in a T cell-specific fashion within a set of human and mouse cell lines. In contrast, expression reportedly occurs in multiple nonlymphoid tissues during murine embryogenesis. We have now raised a monoclonal antibody to document expression and biochemistry of the human TCF-1 protein. As expected, the TCF-1 protein was detectable only in cell lines of T lineage. Its expression was always restricted to the nucleus. Immunohistochemistry on a panel of human tissues revealed that the TCF-1 protein was found exclusively in thymocytes and in CD3+ T cells in peripheral lymphoid tissues. Western blotting yielded a set of bands ranging from 25 kD to 55 kD, resulting from extensive alternative splicing. The TCF-1 protein was detectable in all samples of a set of 22 T-cell malignancies of various stages of maturation, but was absent from a large number of other hematologic neoplasms. These observations imply a T cell-specific function for TCF-1, a notion corroborated by recent observations on Tcf-1 knock-out mice. In addition, these results indicate that nuclear TCF-1 expression can serve as a pan-T-lineage marker in the diagnosis of lymphoid malignancies.


1987 ◽  
Vol 7 (6) ◽  
pp. 2286-2293 ◽  
Author(s):  
V C Bond ◽  
B Wold

Poly-L-ornithine has been used to introduce DNA and RNA into mammalian cells in culture. Ornithine-mediated DNA transfer has several interesting and potentially useful properties. The procedure is technically straightforward and is easily applied to either small or large numbers of recipient cells. The efficiency of transformation is high. Under optimal conditions, 1 to 2% of recipient mouse L cells take up and continue to express selectable marker genes. DNA content of transformants can be varied reproducibly, yielding cells with just one or two copies of the new gene under one set of conditions, while under a different set of conditions 25 to 50 copies are acquired. Cotransformation and expression of physically unlinked genes occur at high efficiency under conditions favoring multiple-copy transfer. Polyornithine promotes gene transfer into cell lines other than L cells. These include Friend erythroleukemia cells and NIH 3T3 cells. Both are transformed about 1 order of magnitude more efficiently by this procedure than by standard calcium phosphate products. However, the method does not abolish the large transformation efficiency differences between these cell lines that have been observed previously by other techniques. (vi) mRNA synthesized in vitro was also introduced into cells by this method. The RNA was translated resulting in a transient accumulation of the protein product.


1988 ◽  
Vol 8 (10) ◽  
pp. 4185-4189 ◽  
Author(s):  
J A Greenspan ◽  
F M Xu ◽  
R L Davidson

The molecular mechanisms of ethyl methanesulfonate-induced reversion in mammalian cells were studied by using as a target a gpt gene that was integrated chromosomally as part of a shuttle vector. Murine cells containing mutant gpt genes with single base changes were mutagenized with ethyl methanesulfonate, and revertant colonies were isolated. Ethyl methanesulfonate failed to increase the frequency of revertants for cell lines with mutant gpt genes carrying GC----AT transitions or AT----TA transversions, whereas it increased the frequency 50-fold to greater than 800-fold for cell lines with mutant gpt genes carrying AT----GC transitions and for one cell line with a GC----CG transversion. The gpt genes of 15 independent revertants derived from the ethyl methanesulfonate-revertible cell lines were recovered and sequenced. All revertants derived from cell lines with AT----GC transitions had mutated back to the wild-type gpt sequence via GC----AT transitions at their original sites of mutation. Five of six revertants derived from the cell line carrying a gpt gene with a GC----CG transversion had mutated via GC----AT transition at the site of the original mutation or at the adjacent base in the same triplet; these changes generated non-wild-type DNA sequences that code for non-wild-type amino acids that are apparently compatible with xanthine-guanine phosphoribosyltransferase activity. The sixth revertant had mutated via CG----GC transversion back to the wild-type sequence. The results of this study define certain amino acid substitutions in the xanthine-guanine phosphoribosyltransferase polypeptide that are compatible with enzyme activity. These results also establish mutagen-induced reversion analysis as a sensitive and specific assay for mutagenesis in mammalian cells.


2017 ◽  
Vol 36 (6) ◽  
pp. 478-484 ◽  
Author(s):  
Gagandeep Singh ◽  
James Beddow ◽  
Christopher Mee ◽  
Lidia Maryniak ◽  
Eadaoin M. Joyce ◽  
...  

Copper and copper compounds have multifunctional properties (antibacterial, antiviral, and antifungal) with promising applications. Copper in its nanoparticle (Cu NPs) forms has been widely used in various industrial and commercial applications. In the current research, the cytotoxic effects of textile fabrics impregnated with copper oxide nanoparticles (CuO NPs) were studied in mammalian cell lines. CuO NPs were impregnated onto textile substrates using 2 different techniques: the sonochemical generation and impregnation of NPs from metal complexes ( insitu) and a “throwing the stones” technology using commercially prepared CuO NPs. The cytotoxicity of these 2 textile fabric types was assayed on human dermal fibroblast (HDF) cells and human hepatocellular carcinoma cells (HepG2) and was evaluated by indirect contact using an MTT assay. The impregnated fabrics were not exposed to the cells, rather their leachates were used to test cytotoxicity. The fabrics were soaked into the growth media for up to 7 days, and the leachates from day 1 and day 7 were incubated with the cell lines for 24 hours prior to the testing. The discharge or leaching from antimicrobial nanomaterials into the surroundings and surface waters is posing a serious environmental threat, which needs to be addressed. Hence, with regard to product safety, it is a good approach to study the fabric leachates rather than the intact material. The results showed that CuO NPs are not toxic to HDF cells. However, cytotoxicity was seen in HepG2 cells with cell viability decreasing by 20% to 25% for all the fabrics after 24 hours.


1973 ◽  
Vol 12 (1) ◽  
pp. 263-274
Author(s):  
P. W. ALLDERDICE ◽  
O. J. MILLER ◽  
D. A. MILLER ◽  
D. WARBURTON ◽  
P. L. PEARSON ◽  
...  

The fluorescent banding patterns of quinacrine-stained metaphase chromosomes have been studied in 2 related mouse cell lines, A9 and a malignant derivative of A9, A9HT. In both cell lines virtually every chromosome has a distinctive banding pattern which permits its recognition. More than three quarters of the chromosomes have structural rearrangements, but the origin of nearly two thirds of the chromosomes could be determined by their banding patterns. The quinacrine fluorescence technique permits far more detailed characterization and comparison of heteroploid cell lines than any previous method. A9 and A9HT are karyologically quite similar, with many of the same marker chromosomes. There are, however, characteristic differences. A9HT, although it has a smaller average number of chromosomes per cell, appears to be more heterogeneous.


2015 ◽  
Vol 9 (29) ◽  
pp. 799-805 ◽  
Author(s):  
M Towne Camden ◽  
F Dudt Jan ◽  
B Ray Durwood
Keyword(s):  

A genetic analysis of the resistance phenotype of a recently described chloramphenicol-resistant variant derived from the human cell line, HeLa (MC63), has been undertaken. Whole cells or enucleated fragments, produced by treatment with cytochalasin B, were fused with chloram­phenicol-sensitive mouse, or human cells. Enucleated cells (cytoplasts) act as very efficient donors of the resistance phenotype in fusions with other human cell lines derived from HeLa. We conclude that chloram­phenicol resistance is determined cytoplasmically. Transfer of resistance to unrelated human cell lines occurred at much lower frequency and we were unable to demonstrate transfer to mouse cells. An examination of mitochondrial protein synthesis in the fusion products of cytoplasts and whole cells suggested that mixed populations of mitochondria from both parental cells were maintained under the conditions of selection.


2008 ◽  
Vol 76 (10) ◽  
pp. 4600-4608 ◽  
Author(s):  
Karin Heine ◽  
Sascha Pust ◽  
Stefanie Enzenmüller ◽  
Holger Barth

ABSTRACT The binary C2 toxin from Clostridium botulinum mono-ADP-ribosylates G-actin in the cytosol of eukaryotic cells. This modification leads to depolymerization of actin filaments accompanied by cell rounding within 3 h of incubation but does not immediately induce cell death. Here we investigated the long-term responses of mammalian cell lines (HeLa and Vero) following C2 toxin treatment. Cells stayed round even though the toxin was removed from the medium after its internalization into the cells. No unmodified actin reappeared in the C2 toxin-treated cells within 48 h. Despite actin being completely ADP-ribosylated after about 7 h, no obvious decrease in the overall amount of actin was observed for at least 48 h. Therefore, ADP-ribosylation was not a signal for an accelerated degradation of actin in the tested cell lines. C2 toxin treatment resulted in delayed apoptotic cell death that became detectable about 15 to 24 h after toxin application in a portion of the cells. Poly(ADP)-ribosyltransferase 1 (PARP-1) was cleaved in C2 toxin-treated cells, an indication of caspase 3 activation and a hallmark of apoptosis. Furthermore, specific caspase inhibitors prevented C2 toxin-induced apoptosis, implying that caspases 8 and 9 were activated in C2 toxin-treated cells. C2I, the ADP-ribosyltransferase component of the C2 toxin, remained active in the cytosol for at least 48 h, and no extensive degradation of C2I was observed. From our data, we conclude that the long-lived nature of C2I in the host cell cytosol was essential for the nonreversible cytotoxic effect of C2 toxin, resulting in delayed apoptosis of the tested mammalian cells.


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