scholarly journals Relative cytotoxicity of complexes of platinum(II) and palladium(II) against pure cell culture Paramecium caudatum and human cell lines A431 and HaCaT

2018 ◽  
Vol 7 (1) ◽  
pp. 28-38 ◽  
Author(s):  
Aleksei Vladimirovich Eremin ◽  
Roman Vladimirovich Suezov ◽  
Polina Sergeevna Grishina ◽  
Alexander Ivanovich Ponyaev ◽  
Nicolay Leonidovich Medvedskiy
Keyword(s):  
Cell Culture ◽  
Cell Lines ◽  
Mtt Assay ◽  
Human Cell ◽  
Human Cells ◽  
Epidermoid Carcinoma ◽  
Binuclear Complexes ◽  
Human Cell Lines ◽  
Paramecium Caudatum ◽  
Pure Cell

The results of cytotoxicity cis-diamine mono- and binuclear complexes of platinum(II) and palladium(II) are presented. The cytotoxicity was investigated by the method of biotesting with Paramecium caudatum and by MTT-assay with human cells: epidermoid carcinoma A431 and minimal transformed aneuploid keratinocytes HaCaT. Cytotoxicity of complexes towards protists is higher than against human cells, however, comparatively, HaCaT is more sensitive than A431 by the treatment all complexes. It is noted that cytotoxicity of palladium(II) complexes is higher than the analogues with platinum(II).

Altered gene expression during cellular aging

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 386-389 ◽  
Author(s):  
James R. Smith ◽  
Olivia M. Pereira-Smith
Keyword(s):  
Gene Expression ◽  
Dna Synthesis ◽  
Cell Lines ◽  
Cellular Senescence ◽  
Human Cell ◽  
Messenger Rna ◽  
Human Cells ◽  
Cellular Aging ◽  
Human Cell Lines ◽  
Normal Human

The limited division potential of normal human diploid fibroblasts in culture represents a model system for cellular aging. Observations indicate cellular senescence is an active process. Senescent cells, although unable to divide, are actively metabolizing. Hybrids from fusion of normal and immortal human cells exhibit limited division potential, suggesting that the phenotype of cellular senescence is dominant and supporting the hypothesis that senescence is genetically programmed. Fusion of immortal human cell lines with each other has identified four complementation groups for indefinite division. This indicates that a limited number of specific genes or processes are involved in senescence. Senescent cells express highly abundant DNA synthesis inhibitory messenger RNAs and produce a surface membrane associated protein inhibitor of DNA synthesis not expressed in young cells. Senescent cell membranes were used as immunogen to generate three monoclonal antibodies reacting specifically with senescent but not young cells in several normal human cell lines. We have also found that fibronectin messenger RNA accumulates to high levels in senescent cells. The role of these changes in gene expression in senescence is being explored.Key words: cellular senescence, human cells.

scholarly journals HBO1 (KAT7) Does Not Have an Essential Role in Cell Proliferation, DNA Replication, or Histone 4 Acetylation in Human Cells

2019 ◽  
Vol 40 (4) ◽  
Author(s):  
Andrew J. Kueh ◽  
Samantha Eccles ◽  
Leonie Tang ◽  
Alexandra L. Garnham ◽  
Rose E. May ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Adhesion ◽  
Dna Replication ◽  
Cell Lines ◽  
Human Cell ◽  
Human Cells ◽  
Human Cell Lines ◽  
Hela Cell Lines ◽  
Mouse Tissues ◽  
Sirna Knockdown

ABSTRACT HBO1 (MYST2/KAT7) is essential for histone 3 lysine 14 acetylation (H3K14ac) but is dispensable for H4 acetylation and DNA replication in mouse tissues. In contrast, previous studies using small interfering RNA (siRNA) knockdown in human cell lines have suggested that HBO1 is essential for DNA replication. To determine if HBO1 has distinctly different roles in immortalized human cell lines and normal mouse cells, we performed siRNA knockdown of HBO1. In addition, we used CRISPR/Cas9 to generate 293T, MCF7, and HeLa cell lines lacking HBO1. Using both techniques, we show that HBO1 is essential for all H3K14ac in human cells and is unlikely to have a direct effect on H4 acetylation and only has minor effects on cell proliferation. Surprisingly, the loss of HBO1 and H3K14ac in HeLa cells led to the secondary loss of almost all H4 acetylation after 4 weeks. Thus, HBO1 is dispensable for DNA replication and cell proliferation in immortalized human cells. However, while cell proliferation proceeded without HBO1 and H3K14ac, HBO1 gene deletion led to profound changes in cell adhesion, particularly in 293T cells. Consistent with this phenotype, the loss of HBO1 in both 293T and HeLa principally affected genes mediating cell adhesion, with comparatively minor effects on other cellular processes.

scholarly journals Hydroxylation of the Acetyltransferase NAA10 Trp38 Is Not an Enzyme-Switch in Human Cells

2021 ◽  
Vol 22 (21) ◽  
pp. 11805
Author(s):  
Rasmus Ree ◽  
Karoline Krogstad ◽  
Nina McTiernan ◽  
Magnus E. Jakobsson ◽  
Thomas Arnesen
Keyword(s):  
Catalytic Activity ◽  
Cell Lines ◽  
Human Cell ◽  
Hypoxia Inducible Factor ◽  
Human Cells ◽  
Human Proteome ◽  
Human Cell Lines ◽  
Structural Studies ◽  
Hypoxia Inducible Factor 1Α ◽  
Lysine Acetyltransferase

NAA10 is a major N-terminal acetyltransferase (NAT) that catalyzes the cotranslational N-terminal (Nt-) acetylation of 40% of the human proteome. Several reports of lysine acetyltransferase (KAT) activity by NAA10 exist, but others have not been able to find any NAA10-derived KAT activity, the latter of which is supported by structural studies. The KAT activity of NAA10 towards hypoxia-inducible factor 1α (HIF-1α) was recently found to depend on the hydroxylation at Trp38 of NAA10 by factor inhibiting HIF-1α (FIH). In contrast, we could not detect hydroxylation of Trp38 of NAA10 in several human cell lines and found no evidence that NAA10 interacts with or is regulated by FIH. Our data suggest that NAA10 Trp38 hydroxylation is not a switch in human cells and that it alters its catalytic activity from a NAT to a KAT.

scholarly journals Gene knockout shows that PML (TRIM19) does not restrict the early stages of HIV-1 infection in human cell lines

2017 ◽  
Author(s):  
Nasser Masroori ◽  
Pearl Cherry ◽  
Natacha Merindol ◽  
Jia-xin Li ◽  
Caroline Dufour ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Cell ◽  
Gene Knockout ◽  
Human Cells ◽  
Restriction Factor ◽  
Type I ◽  
Human Cell Lines ◽  
Early Stages ◽  
Human T Cell ◽  
Hiv 1

AbstractThe PML (promyelocytic leukemia) protein is a member of the TRIM family, a large group of proteins that show high diversity in functions but possess a common tripartite motif giving the family its name. We and others recently reported that both murine PML (mPML) and human PML (hPML) strongly restrict the early stages of infection by HIV-1 and other lentiviruses when expressed in mouse embryonic fibroblasts (MEFs). This restriction activity was found to contribute to the type I interferon (IFN-I)-mediated inhibition of HIV-1 in MEFs. Additionally, PML caused transcriptional repression of the HIV-1 promoter in MEFs. By contrast, the modulation of the early stages of HIV-1 infection of human cells by PML has been investigated by RNAi with unclear results. In order to conclusively determine whether PML restricts HIV-1 or not in human cells, we used CRISPR-Cas9 to knock out its gene in epithelial, lymphoid and monocytic human cell lines. Infection challenges showed that PML knockout had no effect on the permissiveness of these cells to HIV-1 infection. IFN-I treatments inhibited HIV-1 equally whether PML was expressed or not. Over-expression of individual hPML isoforms, or of mPML, in a human T cell line did not restrict HIV-1. The presence of PML was not required for the restriction of nonhuman retroviruses by TRIM5α was inhibited by arsenic trioxide through a PML-independent mechanism. We conclude that PML is not a restriction factor for HIV-1 in human cell lines representing diverse lineages.ImportancePML is involved in innate immune mechanisms against both DNA and RNA viruses. Although the mechanism by which PML inhibits highly divergent viruses is unclear, it was recently found that it can increase the transcription of interferon-stimulated genes (ISGs). However, whether human PML inhibits HIV-1 has been debated. Here we provide unambiguous, knockout-based evidence that PML does not restrict the early post-entry stages of HIV-1 infection in a variety of human cell types and does not participate in the inhibition of HIV-1 by IFN-I. Although this study does not exclude the possibility of other mechanisms by which PML may interfere with HIV-1, we nonetheless demonstrate that PML does not generally act as an HIV-1 restriction factor in human cells and that its presence is not required for IFN-I to stimulate the expression of anti-HIV-1 genes. These results contribute to uncovering the landscape of HIV-1 inhibition by ISGs in human cells.

scholarly journals Gene Knockout Shows That PML (TRIM19) Does Not Restrict the Early Stages of HIV-1 Infection in Human Cell Lines

mSphere ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Nasser Masroori ◽  
Pearl Cherry ◽  
Natacha Merindol ◽  
Jia-xin Li ◽  
Caroline Dufour ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Cell ◽  
Gene Knockout ◽  
Human Cells ◽  
Restriction Factor ◽  
Type I ◽  
Human Cell Lines ◽  
Early Stages ◽  
Human T Cell ◽  
Hiv 1

ABSTRACTThe PML (promyelocytic leukemia) protein is a member of the TRIM family, a large group of proteins that show high diversity in functions but possess a common tripartite motif giving the family its name. We and others recently reported that both murine PML (mPML) and human PML (hPML) strongly restrict the early stages of infection by HIV-1 and other lentiviruses when expressed in mouse embryonic fibroblasts (MEFs). This restriction activity was found to contribute to the type I interferon (IFN-I)-mediated inhibition of HIV-1 in MEFs. Additionally, PML caused transcriptional repression of the HIV-1 promoter in MEFs. In contrast, the modulation of the early stages of HIV-1 infection of human cells by PML has been investigated by RNA interference, with unclear results. In order to conclusively determine whether PML restricts HIV-1 or not in human cells, we used the clustered regularly interspaced short palindromic repeat with Cas9 (CRISPR-Cas9) system to knock out its gene in epithelial, lymphoid, and monocytic human cell lines. Infection challenges showed that PML knockout had no effect on the permissiveness of these cells to HIV-1 infection. IFN-I treatments inhibited HIV-1 equally whether PML was expressed or not. Overexpression of individual hPML isoforms, or of mPML, in a human T cell line did not restrict HIV-1. The presence of PML was not required for the restriction of nonhuman retroviruses by TRIM5α (another human TRIM protein), and TRIM5α was inhibited by arsenic trioxide through a PML-independent mechanism. We conclude that PML is not a restriction factor for HIV-1 in human cell lines representing diverse lineages.IMPORTANCEPML is involved in innate immune mechanisms against both DNA and RNA viruses. Although the mechanism by which PML inhibits highly divergent viruses is unclear, it was recently found that it can increase the transcription of interferon-stimulated genes (ISGs). However, whether human PML inhibits HIV-1 has been debated. Here we provide unambiguous, knockout-based evidence that PML does not restrict the early postentry stages of HIV-1 infection in a variety of human cell types and does not participate in the inhibition of HIV-1 by IFN-I. Although this study does not exclude the possibility of other mechanisms by which PML may interfere with HIV-1, we nonetheless demonstrate that PML does not generally act as an HIV-1 restriction factor in human cells and that its presence is not required for IFN-I to stimulate the expression of anti-HIV-1 genes. These results contribute to uncovering the landscape of HIV-1 inhibition by ISGs in human cells.

scholarly journals In vitro cytotoxicity of different dental resin-cements on human cell lines

2021 ◽  
Vol 32 (1) ◽  
Author(s):  
Freya Diemer ◽  
Helmut Stark ◽  
Ernst-Heinrich Helfgen ◽  
Norbert Enkling ◽  
Rainer Probstmeier ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Viability ◽  
Cell Lines ◽  
Human Cell ◽  
Zinc Phosphate ◽  
Human Cell Lines ◽  
Cell Type ◽  
Direct Stimulation ◽  
Resin Cements

AbstractAdhesive resin-cements are increasingly used in modern dentistry. Nevertheless, released substances from resin materials have been shown to cause cellular toxic effects. Disc-shaped specimens from 12 different resin cements and one conventional zinc phosphate cement were prepared and used for direct stimulation of five different human cell lines via transwell cell culture system or in an indirect way using conditioned cell culture media. Cytotoxicity was determined using LDH and BCA assays. All tested cements led to a decrease of cell viability but to a distinct extent depending on cell type, luting material, and cytotoxicity assay. In general, cements exhibited a more pronounced cytotoxicity in direct stimulation experiments compared to stimulations using conditioned media. Interestingly, the conventional zinc phosphate cement showed the lowest impact on cell viability. On cellular level, highest cytotoxic effects were detected in osteoblastic cell lines. All resin cements reduced cell viability of human cells with significant differences depending on cell type and cement material. Especially, osteoblastic cells demonstrated a tremendous increase of cytotoxicity after cement exposure. Although the results of this in vitro study cannot be transferred directly to a clinical setting, it shows that eluted substances from resin cements may disturb osteoblastic homeostasis that in turn could lead to conditions favoring peri-implant bone destruction. Thus, the wide use of resin cements in every clinical situation should be scrutinized. A correct use with complete removal of all cement residues and a sufficient polymerization should be given the utmost attention in clinical usage.

scholarly journals Cell Culture Systems To Study Human Herpesvirus 6A/B Chromosomal Integration

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Annie Gravel ◽  
Isabelle Dubuc ◽  
Nina Wallaschek ◽  
Shella Gilbert-Girard ◽  
Vanessa Collin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Cell Lines ◽  
Human Cell ◽  
Histone Deacetylase Inhibitors ◽  
Viral Integration ◽  
Viral Gene ◽  
Human Cell Lines ◽  
Cellular Factors ◽  
Viral Genes

ABSTRACT Human herpesviruses 6A/B (HHV-6A/B) can integrate their viral genomes in the telomeres of human chromosomes. The viral and cellular factors contributing to HHV-6A/B integration remain largely unknown, mostly due to the lack of efficient and reproducible cell culture models to study HHV-6A/B integration. In this study, we characterized the HHV-6A/B integration efficiencies in several human cell lines using two different approaches. First, after a short-term infection (5 h), cells were processed for single-cell cloning and analyzed for chromosomally integrated HHV-6A/B (ciHHV-6A/B). Second, cells were infected with HHV-6A/B and allowed to grow in bulk for 4 weeks or longer and then analyzed for the presence of ciHHV-6. Using quantitative PCR (qPCR), droplet digital PCR, and fluorescent in situ hybridization, we could demonstrate that HHV-6A/B integrated in most human cell lines tested, including telomerase-positive (HeLa, MCF-7, HCT-116, and HEK293T) and telomerase-negative cell lines (U2OS and GM847). Our results also indicate that inhibition of DNA replication, using phosphonoacetic acid, did not affect HHV-6A/B integration. Certain clones harboring ciHHV-6A/B spontaneously express viral genes and proteins. Treatment of cells with phorbol ester or histone deacetylase inhibitors triggered the expression of many viral genes, including U39, U90, and U100, without the production of infectious virus, suggesting that the tested stimuli were not sufficient to trigger full reactivation. In summary, both integration models yielded comparable results and should enable the identification of viral and cellular factors contributing to HHV-6A/B integration and the screening of drugs influencing viral gene expression, as well as the release of infectious HHV-6A/B from the integrated state. IMPORTANCE The analysis and understanding of HHV-6A/B genome integration into host DNA is currently limited due to the lack of reproducible and efficient viral integration systems. In the present study, we describe two quantitative cell culture viral integration systems. These systems can be used to define cellular and viral factors that play a role in HHV-6A/B integration. Furthermore, these systems will allow us to decipher the conditions resulting in virus gene expression and excision of the integrated viral genome resulting in reactivation.

scholarly journals Disruption of microtubule function in cultured human cells by a cytotoxic ruthenium(ii) polypyridyl complex

2020 ◽  
Vol 11 (1) ◽  
pp. 264-275 ◽  
Author(s):  
Nagham Alatrash ◽  
Faiza H. Issa ◽  
Nada S. Bawazir ◽  
Savannah J. West ◽  
Kathleen E. Van Manen-Brush ◽  
...  
Keyword(s):  
Cell Lines ◽  
Human Cell ◽  
Human Cells ◽  
Human Cell Lines ◽  
Polypyridyl Complex ◽  
Cultured Human Cells ◽  
Microtubule Function

Treatment of cultured human cell lines with a cytotoxic IC50 dose of ∼2 μM tris(diphenylphenanthroline)ruthenium(ii) chloride (RPC2) retards or arrests microtubule motion as tracked by visualizing fluorescently-tagged microtubule plus end-tracking proteins.

scholarly journals Identification of Human Junctional Adhesion Molecule 1 as a Functional Receptor for the Hom-1 Calicivirus on Human Cells

mBio ◽  
2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Stanislav V. Sosnovtsev ◽  
Carlos Sandoval-Jaime ◽  
Gabriel I. Parra ◽  
Christine M. Tin ◽  
Ronald W. Jones ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Cell Lines ◽  
Adhesion Molecule ◽  
Human Cell ◽  
Cho Cells ◽  
Human Cells ◽  
Human Cell Lines ◽  
Sea Lion ◽  
Functional Receptor

ABSTRACTThe Hom-1 vesivirus was reported in 1998 following the inadvertent transmission of the animal calicivirus San Miguel sea lion virus to a human host in a laboratory. We characterized the Hom-1 strain and investigated the mechanism by which human cells could be infected. An expression library of 3,559 human plasma membrane proteins was screened for reactivity with Hom-1 virus-like particles, and a single interacting protein, human junctional adhesion molecule 1 (hJAM1), was identified. Transient expression of hJAM1 conferred susceptibility to Hom-1 infection on nonpermissive Chinese hamster ovary (CHO) cells. Virus infection was markedly inhibited when CHO cells stably expressing hJAM were pretreated with anti-hJAM1 monoclonal antibodies. Cell lines of human origin were tested for growth of Hom-1, and efficient replication was observed in HepG2, HuH7, and SK-CO15 cells. The three cell lines (of hepatic or intestinal origin) were confirmed to express hJAM1 on their surface, and clustered regularly interspaced short palindromic repeats/Cas9-mediated knockout of the hJAM1 gene in each line abolished Hom-1 propagation. Taken together, our data indicate that entry of the Hom-1 vesivirus into these permissive human cell lines is mediated by the plasma membrane protein hJAM1 as a functional receptor.IMPORTANCEVesiviruses, such as San Miguel sea lion virus and feline calicivirus, are typically associated with infection in animal hosts. Following the accidental infection of a laboratory worker with San Miguel sea lion virus, a related virus was isolated in cell culture and named Hom-1. In this study, we found that Hom-1 could be propagated in a number of human cell lines, making it the first calicivirus to replicate efficiently in cultured human cells. Screening of a library of human cell surface membrane proteins showed that the virus could utilize human junctional adhesion molecule 1 as a receptor to enter cells and initiate replication. The Hom-1 virus presents a new system for the study of calicivirus biology and species specificity.

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