Response of Mammalian Cells to Metabolic Stress; Changes in Cell Physiology and Structure/Function of Stress Proteins

1991 ◽  
pp. 31-55 ◽  
Author(s):  
W. J. Welch ◽  
H. S. Kang ◽  
R. P. Beckmann ◽  
L. A. Mizzen
Keyword(s):  
Structure Function ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Metabolic Stress ◽  
Cell Physiology ◽  
Stress Changes

Structure, function and techniques of investigation of the P2X7 receptor (P2X7R) in mammalian cells

2019 ◽  
pp. 115-150 ◽  
Author(s):  
Francesco Di Virgilio ◽  
Lin-Hua Jiang ◽  
Sébastien Roger ◽  
Simonetta Falzoni ◽  
Alba Clara Sarti ◽  
...  
Keyword(s):  
Structure Function ◽  
Mammalian Cells ◽  
P2x7 Receptor

scholarly journals Antioxidants and selenocompounds inhibit 3,5-dimethylaminophenol toxicity to human urothelial cells

2019 ◽  
Vol 70 (1) ◽  
pp. 18-29 ◽  
Author(s):  
Pinar Erkekoglu ◽  
Ming-Wei Chao ◽  
Chia-Yi Tseng ◽  
Bevin P. Engelward ◽  
Ozge Kose ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bladder Cancer ◽  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Mammalian Cells ◽  
Antioxidant Enzyme Activities ◽  
Urothelial Cells ◽  
Dna Breaks ◽  
Primary Metabolite ◽  
Stress Changes

AbstractExposure to alkyl anilines may lead to bladder cancer, which is the second most frequent cancer of the urogenital tract. 3,5-dimethylaniline is highly used in industry. Studies on its primary metabolite 3,5-dimethylaminophenol (3,5-DMAP) showed that this compound causes oxidative stress, changes antioxidant enzyme activities, and leads to death of different mammalian cells. However, there is no in vitro study to show the direct effects of 3,5-DMAP on human bladder and urothelial cells. Selenocompounds are suggested to decrease oxidative stress caused by some chemicals, and selenium supplementation was shown to reduce the risk of bladder cancer. The main aim of this study was to investigate whether selenocompounds organic selenomethionine (SM, 10 µmol/L) or inorganic sodium selenite (SS, 30 nmol/L) could reduce oxidative stress, DNA damage, and apoptosis in UROtsa cells exposed to 3,5-DMAP. 3,5-DMAP caused a dose-dependent increase in intracellular generation of reactive oxygen species, and its dose of 50 µmol/L caused lipid peroxidation, protein oxidation, and changes in antioxidant enzyme activities in different cellular fractions. The comet assay also showed single-strand DNA breaks induced by the 3,5-DMAP dose of 50 µmol/L, but no changes in double-strand DNA breaks. Apoptosis was also triggered. Both selenocompounds provided partial protection against the cellular toxicity of 3,5-DMAP. Low selenium status along with exposure to alkyl anilines can be a major factor in the development of bladder cancer. More mechanistic studies are needed to specify the role of selenium in bladder cancer.

scholarly journals Construction of a Nanosensor for Non-Invasive Imaging of Hydrogen Peroxide Levels in Living Cells

Biology ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 430
Author(s):  
Amreen ◽  
Hayssam M. Ali ◽  
Mohammad Ahmad ◽  
Mohamed Z. M. Salem ◽  
Altaf Ahmad
Keyword(s):  
Hydrogen Peroxide ◽  
Real Time ◽  
Mammalian Cells ◽  
Dynamic Range ◽  
Resonance Energy ◽  
Living Cells ◽  
Stress Conditions ◽  
Live Cells ◽  
Cell Physiology ◽  
Broad Dynamic Range

Hydrogen peroxide (H2O2) serves fundamental regulatory functions in metabolism beyond the role as damage signal. During stress conditions, the level of H2O2 increases in the cells and causes oxidative stress, which interferes with normal cell growth in plants and animals. The H2O2 also acts as a central signaling molecule and regulates numerous pathways in living cells. To better understand the generation of H2O2 in environmental responses and its role in cellular signaling, there is a need to study the flux of H2O2 at high spatio–temporal resolution in a real-time fashion. Herein, we developed a genetically encoded Fluorescence Resonance Energy Transfer (FRET)-based nanosensor (FLIP-H2O2) by sandwiching the regulatory domain (RD) of OxyR between two fluorescent moieties, namely ECFP and mVenus. This nanosensor was pH stable, highly selective to H2O2, and showed insensitivity to other oxidants like superoxide anions, nitric oxide, and peroxynitrite. The FLIP-H2O2 demonstrated a broad dynamic range and having a binding affinity (Kd) of 247 µM. Expression of sensor protein in living bacterial, yeast, and mammalian cells showed the localization of the sensor in the cytosol. The flux of H2O2 was measured in these live cells using the FLIP-H2O2 under stress conditions or by externally providing the ligand. Time-dependent FRET-ratio changes were recorded, which correspond to the presence of H2O2. Using this sensor, real-time information of the H2O2 level can be obtained non-invasively. Thus, this nanosensor would help to understand the adverse effect of H2O2 on cell physiology and its role in redox signaling.

scholarly journals Disruption of the three cytoskeletal networks in mammalian cells does not affect transcription, translation, or protein translocation changes induced by heat shock.

1985 ◽  
Vol 5 (7) ◽  
pp. 1571-1581 ◽  
Author(s):  
W J Welch ◽  
J R Feramisco
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Protein Translocation ◽  
Shock Response ◽  
Cytochalasin E ◽  
Cytoskeletal Networks ◽  
Shock Proteins ◽  
Cytoskeletal Elements

Mammalian cells show a complex series of transcriptional and translational switching events in response to heat shock treatment which ultimately lead to the production and accumulation of a small number of proteins, the so-called heat shock (or stress) proteins. We investigated the heat shock response in both qualitative and quantitative ways in cells that were pretreated with drugs that specifically disrupt one or more of the three major cytoskeletal networks. (These drugs alone, cytochalasin E and colcemid, do not result in induction of the heat shock response.) Our results indicated that disruption of the actin microfilaments, the vimentin-containing intermediate filaments, or the microtubules in living cells does not hinder the ability of the cell to undergo an apparently normal heat shock response. Even when all three networks were simultaneously disrupted (resulting in a loose, baglike appearance of the cells), the cells still underwent a complete heat shock response as assayed by the appearance of the heat shock proteins. In addition, the major induced 72-kilodalton heat shock protein was efficiently translocated from the cytoplasm into its proper location in the nucleus and nucleolus irrespective of the condition of the three cytoskeletal elements.

Effect of Panax Ginseng Saponins and Eleutherococcus Senticosus on Survival of Cultured Mammalian Cells After Ionizing Radiation

1981 ◽  
Vol 09 (01) ◽  
pp. 48-56 ◽  
Author(s):  
Ehud Ben-Hur ◽  
Stephen Fulder
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Panax Ginseng ◽  
Radiation Resistance ◽  
Mammalian Cells ◽  
Cell Physiology ◽  
Γ Irradiation ◽  
Eleutherococcus Senticosus ◽  
Cells In Culture ◽  
Ginseng Saponin

Panax ginseng saponins and Eleutherococcus senticosus extract were applied to cells in culture in order to assess the effect of these substances on resistance to γ-irradiation. Eleutherococcus was slightly radio protective. However, ginseng saponin at a dose of 10 μg/ml was significantly radio-protective (Do = 2.25 Gy) compared to control (Do = 1.80 Gy) when it was present prior to γ-irradiation (Do = 1.10 Gy). Ginseng-treated cells made 30% less RNA and 14% more protein during a 1 hour pulse of labeled intermediates. The cells were morphologically altered. It is concluded that ginseng saponin can increased radiation resistance. The effect is indirect, due to alterations in cell physiology rather that DNA repair processes.

scholarly journals Intercellular mRNA trafficking via membrane nanotube-like extensions in mammalian cells

2017 ◽  
Vol 114 (46) ◽  
pp. E9873-E9882 ◽  
Author(s):  
Gal Haimovich ◽  
Christopher M. Ecker ◽  
Margaret C. Dunagin ◽  
Elliott Eggan ◽  
Arjun Raj ◽  
...  
Keyword(s):  
Single Molecule ◽  
Mammalian Cells ◽  
De Novo ◽  
Full Length ◽  
Cell Physiology ◽  
Donor And Acceptor ◽  
Immortalized Cells ◽  
Rna Fragments ◽  
Direct Cell ◽  
Structural Connection

RNAs have been shown to undergo transfer between mammalian cells, although the mechanism behind this phenomenon and its overall importance to cell physiology is not well understood. Numerous publications have suggested that RNAs (microRNAs and incomplete mRNAs) undergo transfer via extracellular vesicles (e.g., exosomes). However, in contrast to a diffusion-based transfer mechanism, we find that full-length mRNAs undergo direct cell–cell transfer via cytoplasmic extensions characteristic of membrane nanotubes (mNTs), which connect donor and acceptor cells. By employing a simple coculture experimental model and using single-molecule imaging, we provide quantitative data showing that mRNAs are transferred between cells in contact. Examples of mRNAs that undergo transfer include those encoding GFP, mouse β-actin, and human Cyclin D1, BRCA1, MT2A, and HER2. We show that intercellular mRNA transfer occurs in all coculture models tested (e.g., between primary cells, immortalized cells, and in cocultures of immortalized human and murine cells). Rapid mRNA transfer is dependent upon actin but is independent of de novo protein synthesis and is modulated by stress conditions and gene-expression levels. Hence, this work supports the hypothesis that full-length mRNAs undergo transfer between cells through a refined structural connection. Importantly, unlike the transfer of miRNA or RNA fragments, this process of communication transfers genetic information that could potentially alter the acceptor cell proteome. This phenomenon may prove important for the proper development and functioning of tissues as well as for host–parasite or symbiotic interactions.

scholarly journals Heat-induced Alterations in the Localization of HSP72 and HSP73 as Measured by Indirect Immunohistochemistry and Immunogold Electron Microscopy

2000 ◽  
Vol 48 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Sarah Ellis ◽  
Marilyn Killender ◽  
Robin L. Anderson
Keyword(s):  
Electron Microscopy ◽  
Heat Stress ◽  
Molecular Chaperones ◽  
Mammalian Cells ◽  
Stress Proteins ◽  
Immunogold Electron Microscopy ◽  
Mitotic Chromosomes ◽  
Microscopy Technique ◽  
Before And After ◽  
Shock Proteins

The heat shock proteins are a family of stress-inducible proteins that act as molecular chaperones for nascent proteins and assist in protection and repair of proteins whose conformation is altered by stress. HSP72 and HSP73 are two major cytosolic/nuclear stress proteins of mammalian cells, with extensive sequence homology. HSP73 is constitutively expressed, whereas HSP72 is highly stress-inducible. However, it is unclear why two isoforms are expressed and whether these two proteins have different functions in the cell. To assist in the delineation of function, we have completed a detailed study of the localization of HSP72 and HSP73 in the cell before and after heat stress, using two different methods of detection. By indirect immunohistochemistry, the localization of these two proteins is similar, cytoplasmic and nuclear in nonstressed cells with a translocation to nucleoli immediately after heat. By the more sensitive immunogold electron microscopy technique, differences in localization were noted. In nonstressed cells, HSP72 was primarily nuclear, localized in heterochromatic regions and in nucleoli. HSP73 was distributed throughout the cell, with most cytoplasmic label associated with mitochondria. Mitotic chromosomes were also heavily labeled. After stress, HSP72 concentrated in nuclei and nucleoli and HSP73 localized to nuclei, nucleoli, and cytoplasm, with increased label over mitochondria. These differences in localization suggest that the HSP72 and HSP73 may associate with different proteins or complexes and hence have different but overlapping functions in the cell.

Mitogen-Activated Protein Kinase: Conservation of a Three-Kinase Module From Yeast to Human

1999 ◽  
Vol 79 (1) ◽  
pp. 143-180 ◽  
Author(s):  
CHRISTIAN WIDMANN ◽  
SPENCER GIBSON ◽  
MATTHEW B. JARPE ◽  
GARY L. JOHNSON
Keyword(s):  
Protein Kinase ◽  
Protein Kinases ◽  
Mammalian Cells ◽  
Mitogen Activated Protein Kinase ◽  
Cell Physiology ◽  
Mitogen Activated Protein Kinases ◽  
Mapk Kinase ◽  
Mapk Pathways ◽  
Mitogen Activated Protein ◽  
Sequential Activation

Widmann, Christian, Spencer Gibson, Matthew B. Jarpe, and Gary L. Johnson. Mitogen-Activated Protein Kinase: Conservation of a Three-Kinase Module From Yeast to Human. Physiol. Rev. 79: 143–180, 1999. — Mitogen-activated protein kinases (MAPK) are serine-threonine protein kinases that are activated by diverse stimuli ranging from cytokines, growth factors, neurotransmitters, hormones, cellular stress, and cell adherence. Mitogen-activated protein kinases are expressed in all eukaryotic cells. The basic assembly of MAPK pathways is a three-component module conserved from yeast to humans. The MAPK module includes three kinases that establish a sequential activation pathway comprising a MAPK kinase kinase (MKKK), MAPK kinase (MKK), and MAPK. Currently, there have been 14 MKKK, 7 MKK, and 12 MAPK identified in mammalian cells. The mammalian MAPK can be subdivided into five families: MAPKerk1/2, MAPKp38, MAPKjnk, MAPKerk3/4, and MAPKerk5. Each MAPK family has distinct biological functions. In Saccharomyces cerevisiae, there are five MAPK pathways involved in mating, cell wall remodelling, nutrient deprivation, and responses to stress stimuli such as osmolarity changes. Component members of the yeast pathways have conserved counterparts in mammalian cells. The number of different MKKK in MAPK modules allows for the diversity of inputs capable of activating MAPK pathways. In this review, we define all known MAPK module kinases from yeast to humans, what is known about their regulation, defined MAPK substrates, and the function of MAPK in cell physiology.

NanoLiterBioReactor: Monitoring of Long-Term Mammalian Cell Physiology at Nanofabricated Scale

2004 ◽  
Vol 820 ◽  
Author(s):  
Ales Prokop ◽  
Zdenka Prokop ◽  
David Schaffer ◽  
Eugene Kozlov ◽  
John Wikswo ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Cell Counting ◽  
Cell Physiology ◽  
Mammalian Cell Lines ◽  
Cell Counts ◽  
Multiple Cell

AbstractThere is a need for microminiaturized cell-culture environments, i.e., NanoLiter BioReactors (NBRs), for growing and maintaining populations of up to several hundred cultured mammalian cells in volumes three orders of magnitude smaller than those contained in standard multi-well screening plates. Reduced NBR volumes would not only shorten the time required for diffusive mixing, for achieving thermal equilibrium, and for cells to grow to confluence, but also simplify accurate cell counting, minimize required volumes of expensive analytical pharmaceuticals or toxins, and allow for thousands of culture chambers on a single instrumented chip. These devices would enable the development of a new class of miniature, automated cell-based bioanalysis arrays for monitoring the immediate environment of multiple cell lines and assessing the effects of drug or toxin exposure. The challenge, beyond that of optimizing the NBR physically, is to detect cellular response, provide appropriate control signals, and, eventually, facilitate closed-loop adjustments of the environment--e.g., to control temperature, pH, ionic concentration, etc., to maintain homeostasis, or to apply drugs or toxins followed by the adaptive administration of a selective toxin antidote. To characterize in a nonspecific manner the metabolic activity of cells, the biosensor elements of the NBR might include planar pH, dissolved oxygen, and redox potential sensors, or even an isothermal picocalorimeter (pC) to monitor thermodynamic response. Equipped with such sensors, the NBR could be used to perform short- and long-term cultivation of several mammalian cell lines in a perfused system, and to monitor their response to analytes in a massively parallel format. This approach will enable automated, parallel, and multiphasic monitoring of multiple cell lines for drug and toxicology screening. An added bonus is the possibility of studying cell populations with low cell counts whose constituents are completely detached from typical tissue environment, or populations in controlled physical and chemical gradients.

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