... 61 -- Structure and distribution of membrane glycerophospholipids 62 -- Properties of sterols 64 -- Cell ... ... Cells and subcellular fractions 106 -- Balanced salt solutions ? ... ... 6 -- Composition of selected animal cell culture media 107 -- Selected animal cell lines ? ... ... culture media 113 -- MEM noncssential amino acids 114 -- Animal cell culture lines 115 -- Mammalian ... ... surface receptors and their mode of action 126 Properties of cell organelles 127 -- Contents -- >111 ...
Essential data series
xv, 224 s. : il. ; 19 cm
- MeSH
- Cell Biology MeSH
- Cells MeSH
- Molecular Biology MeSH
- Publication type
- Handbook MeSH
- Conspectus
- Buněčná biologie. Cytologie
- NML Fields
- cytologie, klinická cytologie
BACKGROUND: Although it is clear that functional p53 is not required for radiation-induced G2 block, certain experimental findings suggest a role for p53 in this context. For instance, as we also confirm here, the maximum accumulation in the G2 compartment after X-ray exposure occurs much later in p53 mutants than in wild types. It remains to be seen, however, whether this difference is due to a longer block in the G2 phase itself. MATERIAL AND METHODS: We observed the movement of BrdU-labeled cells through G2 and M into G1. From an analysis of the fraction of labeled cells that entered the second posttreatment cell cycle, we were able to determine the absolute duration of the G2 and M phases in unirradiated and irradiated cells. RESULTS: Our experiments with four cell lines, two melanomas and two squamous carcinomas, showed that the radiation-induced delay of transition through the G2 and M phases did not correlate with p53 status. CONCLUSION: We conclude that looking at the accumulation of cells in the G2 compartment alone is misleading when differences in the G2 block are investigated and that the G2 block itself is indeed independent of functional p53.
- MeSH
- Radiation Dosage MeSH
- Neoplasms, Experimental metabolism pathology radiotherapy MeSH
- G2 Phase Cell Cycle Checkpoints radiation effects MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Tumor Suppressor Protein p53 metabolism MeSH
- Cell Survival radiation effects MeSH
- Dose-Response Relationship, Radiation MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
We optimized lipidomics methods to broadly detect endogenous lipids bound to cellular CD1a proteins. Whereas membrane phospholipids dominate in cells, CD1a preferentially captured sphingolipids, especially a C42, doubly unsaturated sphingomyelin (42:2 SM). The natural 42:2 SM but not the more common 34:1 SM blocked CD1a tetramer binding to T cells in all human subjects tested. Thus, cellular CD1a selectively captures a particular endogenous lipid that broadly blocks its binding to TCRs. Crystal structures show that the short cellular SMs stabilized a triad of surface residues to remain flush with CD1a, but the longer lipids forced the phosphocholine group to ride above the display platform to hinder TCR approach. Whereas nearly all models emphasize antigen-mediated T cell activation, we propose that the CD1a system has intrinsic autoreactivity and is negatively regulated by natural endogenous inhibitors selectively bound in its cleft. Further, the detailed chemical structures of natural blockers could guide future design of therapeutic blockers of CD1a response.
- MeSH
- Lymphocyte Activation immunology MeSH
- Antigens, CD1 immunology MeSH
- Cell Membrane immunology MeSH
- Cell Line MeSH
- K562 Cells MeSH
- Phospholipids immunology MeSH
- HEK293 Cells MeSH
- Humans MeSH
- Antigen Presentation immunology MeSH
- Receptors, Antigen, T-Cell immunology MeSH
- T-Lymphocytes immunology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
To tailor cell-surface interactions, precise and controlled attachment of cell-adhesive motifs is required, while any background non-specific cell and protein adhesion has to be blocked effectively. Herein, a versatile and highly reproducible antifouling surface modification based on "clickable" groups and hierarchically structured diblock copolymer brushes for the controlled attachment of cells is reported. The polymer brush architecture combines an antifouling bottom block of poly(2-hydroxyethyl methacrylate) poly(HEMA) and an ultrathin azide-bearing top block, which can participate in well-established "click" reactions including the highly selective copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction under mild conditions. This straightforward approach allows the rapid conjugation of a cell-adhesive, alkyne-bearing cyclic RGD peptide motif, enabling subsequent specific attachment of NIH 3T3 fibroblasts, their extensive proliferation and confluent cell sheet formation after 48 h of incubation. The generally applicable strategy presented in this report can be employed for surface functionalization with diverse alkyne-bearing biological moieties via CuAAC or copper-free alkyne-azide cycloaddition protocols, making it a versatile functionalization approach and a promising tool for tissue engineering, biomaterial implant design, and other applications that require surfaces supporting highly specific cell attachment.
- MeSH
- Alkynes chemistry pharmacology MeSH
- Anti-Infective Agents chemical synthesis pharmacology MeSH
- Azides chemistry pharmacology MeSH
- Biocompatible Materials chemical synthesis pharmacology MeSH
- NIH 3T3 Cells MeSH
- Click Chemistry MeSH
- Cycloaddition Reaction MeSH
- Catalysis MeSH
- Mice MeSH
- Oligopeptides chemistry MeSH
- Polyhydroxyethyl Methacrylate chemistry MeSH
- Cell Proliferation drug effects MeSH
- Tissue Engineering MeSH
- Tissue Scaffolds * MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- MeSH
- Apoptosis * MeSH
- Bacterial Infections physiopathology MeSH
- Models, Biological MeSH
- Cell Line physiology microbiology MeSH
- Cell Cycle * MeSH
- Francisella tularensis * pathogenicity MeSH
- Immunologic Techniques statistics & numerical data MeSH
- Host-Pathogen Interactions * physiology MeSH
- Macrophages microbiology pathology MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
During metastasis, cancer cells navigate through harsh conditions, including various mechanical forces in the bloodstream, highlighting the need to understand the impact of mechanical and shear stresses on cancer cells. To overcome the current methodological limitations of such research, here we present a new device that replicates similar conditions by applying shear stress on cultured cells. The device provides a less complex, easily accessible alternative to traditional fluidics while generating fluid shear stress values comparable to those in human veins and capillaries. The device allows analyses of large cell numbers in standard cell culture flasks and incubators. Using this device to explore the shear stress-induced responses of various human cell lines, we discovered a previously unknown, reversible pre-cytokinetic block occurring in cells that lose anchorage during mitosis and are kept under constant shear stress. Notably, some cancer cell lines appear to bypass this unorthodox cell-cycle block, suggesting its role as a safety checkpoint to restrict the proliferation of cancer cells in the bloodstream and their overall spreading potential. These findings provide new insights into the diverse responses of normal and cancer cells to shear stress and highlight the potential of our technology for research on circulating tumor cells and metastatic spread.
- MeSH
- Humans MeSH
- Stress, Mechanical * MeSH
- Mitosis MeSH
- Cell Line, Tumor MeSH
- Neoplastic Cells, Circulating pathology MeSH
- Neoplasms pathology MeSH
- Shear Strength MeSH
- Cell Proliferation MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Syndrom neonatálního lupusu představuje zajímavý model pasivně získaného autoimunitního onemocnění, u kterého sérum těhotných žen obsahuje specifické autoprotilátky anti-SSA/Ro a anti-SSB/La, které přecházejí placentou a jsou asociovány s možným vývojem vrozeného srdečního bloku plodu a/nebo přechodnými kožními změnami či různými jaterními a krevními abnormalitami u novorozenců. Kompletní vrozený srdeční blok je v současné době považován za ireverzibilní a má významnou morbiditu s nutností implantace trvalého kardiostimulátoru u postižených dětí v různém časovém období po porodu. Perinatální mortalita dosahuje až 20 %. Proto probíhá intenzivní výzkum se zaměřením na patofyziologii vzniku vrozeného srdečního bloku, hledání časných markerů k diagnostice ještě před jeho rozvojem a vhodných léčebných i profylaktických prostředků.
Neonatal lupus syndrome represents a model of passively acquired autoimmunity caused by specific maternal autoantibodies anti-SSA/Ro a anti-SSB/La, which cross the placenta and are associated with the development of congenital heart block in the fetus and/or a transient rash or various liver and blood cell abnormalites in the newborn. Complete form of congenital heart block is a permanent condition that entails significant morbidity, with nearly all affected infants requiring pacemakers. Perinatal mortality may aprroach up to 20 %. An intensive search is therefore ongoing for the specific etiopathophysiology and for diagnostic markers to approach and treat this disease.
- MeSH
- Autoantibodies immunology adverse effects MeSH
- Financing, Organized MeSH
- Pregnancy Complications MeSH
- Humans MeSH
- Fetal Diseases etiology classification mortality MeSH
- Heart Block diagnosis etiology MeSH
- Lupus Erythematosus, Systemic immunology complications blood MeSH
- Check Tag
- Humans MeSH
- Female MeSH
In previous studies we observed that inhibition of cyclic 3',5'-nucleotide phosphodiesterase (PDE) isozymes, namely isozyme PDE3, suppresses proliferation of rat renal glomerular mesangial cells in vitro and in vivo. To determine whether activation of the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway coupled to specific PDE isozymes modulates accelerated proliferation of renal epithelial cells, we investigated the effect of selective PDE isozyme inhibition on renal epithelial cell proliferation induced in rats by injection of folic acid (FA). In extracts from suspensions of renal cortical tubules, cAMP was metabolized predominantly by isozyme PDE4; activity of PDE3 was about three times lower. The increase in proliferative activity of renal cortical tissue from FA-injected rats, evaluated by immunostaining with Mib-1 antibody, was limited to tubular epithelial cells. Administration of the PDE3 inhibitors cilostazol or cilostamide together with the PDE4 inhibitor rolipram blocked mitogenic synthesis of DNA, as determined by (3H)-thymidine incorporation into renal cortical DNA, in FA-treated rats. FA injection caused an increase of more than 10-fold in proliferating cell nuclear antigen (PCNA) in renal cortical tissue; administration of the potent PDE3 inhibitor lixazinone or, to a lesser degree, cilostazol suppressed these high PCNA levels, whereas rolipram alone had no effect. The results indicate that FA-stimulated in vivo proliferation of renal tubular epithelial cells is down-regulated by activation of a cAMP-PKA signaling pathway linked to PDE3 isozymes. These observations are consistent with the notion that negative crosstalk between cAMP signaling and mitogen-stimulated signaling pathways regulates mitogenesis of renal cells of different terminal differentiation, including tubular epithelial cells.
- MeSH
- Cyclic AMP * metabolism MeSH
- Cell Division drug effects MeSH
- 3',5'-Cyclic-AMP Phosphodiesterases * antagonists & inhibitors metabolism MeSH
- Quinazolines pharmacology MeSH
- Quinolones pharmacology MeSH
- Cyclic Nucleotide Phosphodiesterases, Type 3 MeSH
- Down-Regulation physiology MeSH
- Phosphodiesterase Inhibitors * pharmacology MeSH
- Isoenzymes antagonists & inhibitors metabolism MeSH
- Rats MeSH
- Folic Acid pharmacology MeSH
- Kidney Tubules * cytology metabolism drug effects MeSH
- Rats, Sprague-Dawley MeSH
- Proliferating Cell Nuclear Antigen analysis MeSH
- Cyclic AMP-Dependent Protein Kinases metabolism MeSH
- Pyrrolidinones pharmacology MeSH
- Rolipram MeSH
- Signal Transduction drug effects MeSH
- Tetrazoles pharmacology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
