TY - JOUR
AU - Graus, Dorothea
AU - Konrad, Kai R.
AU - Bemm, Felix
AU - Nebioglu, Meliha G. P.
AU - Lorey, Christian
AU - Duscha, Kerstin
AU - Guthoff, Tilman
AU - Herrmann, Johannes
AU - Ferjani, Ali
AU - Cuin, Tracey A.
AU - Roelfsema, M. Rob G.
AU - Schumacher, Karin
AU - Neuhaus, Ekkehard
AU - Marten, Irene
AU - Hedrich, Rainer
T1 - High V-PPase activity is beneficial under high salt loads, but
detrimental without salinity
JO - New Phytologist
PY - 2018/
VL - 219
IS -
SP -
EP -
UR -
DO - 10.1111/nph.15280
KW -
KW -
KW - cells
KW -
KW - leaf
KW - myown
KW - pyrophosphatase
KW -
KW - salt
KW - stress
KW - vacuole
L1 -
SN -
N1 -
N1 -
AB - * The membrane-bound proton-pumping pyrophosphatase (V-PPase), together with the
V-type H+-ATPase, generates the proton motive force that drives vacuolar membrane solute
transport. Transgenic plants constitutively overexpressing V-PPases were shown to have
improved salinity tolerance, but the relative impact of increasing PPi hydrolysis and protonpumping
functions has yet to be dissected.
* For a better understanding of the molecular processes underlying V-PPase-dependent salt
tolerance, we transiently overexpressed the pyrophosphate-driven proton pump (NbVHP) in
Nicotiana benthamiana leaves and studied its functional properties in relation to salt treatment
by primarily using patch-clamp, impalement electrodes and pH imaging.
* NbVHP overexpression led to higher vacuolar proton currents and vacuolar acidification.
After 3 d in salt-untreated conditions, V-PPase-overexpressing leaves showed a drop in
photosynthetic capacity, plasma membrane depolarization and eventual leaf necrosis. Salt,
however, rescued NbVHP-hyperactive cells from cell death. Furthermore, a salt-induced rise
in V-PPase but not of V-ATPase pump currents was detected in nontransformed plants.
* The results indicate that under normal growth conditions, plants need to regulate the
V-PPase pump activity to avoid hyperactivity and its negative feedback on cell viability.
Nonetheless, V-PPase proton pump function becomes increasingly important under salt stress
for generating the pH gradient necessary for vacuolar proton-coupled Na+ sequestration.
ER -
TY - JOUR
AU - Noureini, S.K.
AU - Kheirabadi, M.
AU - Masoumi, F.
AU - Khosrogerdi, F.
AU - Zarei, Y.
AU - Suarez-Rozas, C.
AU - Salas-Norambuena, J.
AU - Cassels, B.K.
T1 - Telomerase Inhibition by a New Synthetic Derivative of the Aporphine Alkaloid Boldine
JO - International Journal of Molecular Sciences
PY - 2018/
VL - 19
IS - 4
SP -
EP -
UR - /brokenurl#://WOS:000434978700318
DO - 10.3390/ijms19041239
KW - apoptosis
KW -
KW - assay
KW - binding
KW - boldine
KW -
KW - cells
KW -
KW - derivative
KW -
KW - domain
KW -
KW - dqcauchile
KW - inhibition
KW -
KW - n-benzylsecoboldine
KW -
KW - site
KW -
KW - stress
KW -
KW - telomerase
L1 -
SN -
N1 -
N1 -
AB - Telomerase, the enzyme responsible for cell immortality, is an important target in anti-cancer drug discovery. Boldine, an abundant aporphine alkaloid of Peumus boldus, is known to inhibit telomerase at non-toxic concentrations. Cytotoxicity of N-benzylsecoboldine hydrochloride (BSB), a synthetic derivative of boldine, was determined using the MTT method in MCF7 and MDA-MB231 cells. Aliquots of cell lysates were incubated with various concentrations of BSB in qTRAP (quantitative telomere repeat amplification protocol)-ligand experiments before substrate elongation by telomerase or amplification by hot-start Taq polymerase. The crystal structure of TERT, the catalytic subunit of telomerase from Tribolium castaneum, was used for docking and molecular dynamics analysis. The qTRAP-ligand data gave an IC50 value of about 0.17 +/- 0.1 mu M for BSB, roughly 400 times stronger than boldine, while the LD50 in the cytotoxicity assays were 12.5 and 21.88 mu M, respectively, in cells treated for 48 h. Although both compounds interacted well with the active site, MD analysis suggests a second binding site with which BSB interacts via two hydrogen bonds, much more strongly than boldine. Theoretical analyses also evaluated the IC50 for BSB as submicromolar. BSB, with greater hydrophobicity and flexibility than boldine, represents a promising structure to inhibit telomerase at non-toxic concentrations.
ER -
TY - JOUR
AU - Celis, F.
AU - Garcia, M.
AU - Diaz-Fleming, G.
AU - Campos-Vallette, M.
T1 - A Review of Raman, Surface-Enhanced Raman Scattering (Sers) and Related Spectroscopic Techniques Applied to Biomolecules in Biomaterials
JO - Journal of the Chilean Chemical Society
PY - 2017/
VL - 62
IS - 3
SP - 3627
EP - 3632
UR - /brokenurl#://WOS:000417443500015
DO -
KW - adsorption
KW -
KW - ag
KW - biomaterials
KW -
KW - biomolecules
KW -
KW - bone
KW -
KW - calcium-phosphate
KW -
KW - cells
KW -
KW - dqcauchile
KW - fragments
KW -
KW - gold
KW - living
KW - nanoparticles
KW -
KW - peptide
KW - raman
KW -
KW - sers
KW -
KW - silver
KW - terminal
KW - ultraviolet
L1 -
SN -
N1 -
N1 -
AB - The development of new biomaterials has gained increasing attention in the last decade. One of the most important aspects in the development of these new materials is to understand the chemical cues presents in the native niche. Among all the techniques currently available for measuring those interactions, Raman spectroscopy offers a unique and non-invasive tool for exploring the behavior of the components within a given biomaterial and their surrounding microenvironment. This technique exploits the unique molecular vibrational fingerprints for pinpointing those interactions. The vibrational response can be improved to the single molecule level, in the presence of metal nanoparticles (NPs) with plasmonic properties (silver, gold and copper) in the so-called SurfaceEnhanced Raman Scattering (SERS), which can be used for in-situ measurements. Another technique recently developed is the Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS), which overcomes signal contamination from chemical interactions between biomolecules and the metal surface; it does this by coating the metal surface with an inert layer of alumina or silica. In the present contribution, the role and the applications of Raman, SERS and related spectroscopic techniques in the study of biomolecules in biomaterials are reviewed and discussed.
ER -
TY - JOUR
AU - Garcia-Beltran, O.
AU - Mena, N.P.
AU - Aguirre, P.
AU - Barriga-Gonzalez, G.
AU - Galdamez, A.
AU - Nagles, E.
AU - Adasme, T.
AU - Hidalgo, C.
AU - Nunez, M.T.
T1 - Development of an Iron-Selective Antioxidant Probe with Protective Effects on Neuronal Function
JO - Plos One
PY - 2017/
VL - 12
IS - 12
SP -
EP -
UR - /brokenurl#://WOS:000417648600030
DO - 10.1371/journal.pone.0189043
KW - calcium
KW - cells
KW -
KW - coumarins
KW -
KW - deficiency
KW -
KW - dqcauchile
KW - fluorescence
KW - fluorescence
KW -
KW - fragmentation
KW -
KW - iron
KW -
KW - labile
KW - mitochondrial
KW - on
KW - oxidative
KW - parkinsons-disease
KW -
KW - probes
KW -
KW - sh-sy5y
KW - stress
L1 -
SN -
N1 -
N1 -
AB - Iron accumulation, oxidative stress and calcium signaling dysregulation are common pathognomonic signs of several neurodegenerative diseases, including Parkinson's and Alzheimer's diseases, Friedreich ataxia and Huntington's disease. Given their therapeutic potential, the identification of multifunctional compounds that suppress these damaging features is highly desirable. Here, we report the synthesis and characterization of N-(1,3-dihydroxy- 2-(hydroxymethyl) propan-2-yl)-2-(7-hydroxy-2-oxo-2H-chromen-4-yl) acetamide, named CT51, which exhibited potent free radical neutralizing activity both in vitro and in cells. CT51 bound Fe2+ with high selectivity and Fe3+ with somewhat lower affinity. Cyclic voltammetric analysis revealed irreversible binding of Fe3+ to CT51, an important finding since stopping Fe2+/Fe3+ cycling in cells should prevent hydroxyl radical production resulting from the Fenton-Haber-Weiss cycle. When added to human neuroblastoma cells, CT51 freely permeated the cell membrane and distributed to both mitochondria and cytoplasm. Intracellularly, CT51 bound iron reversibly and protected against lipid peroxidation. Treatment of primary hippocampal neurons with CT51 reduced the sustained calcium release induced by an agonist of ryanodine receptor-calcium channels. These protective properties of CT51 on cellular function highlight its possible therapeutic use in diseases with significant oxidative, iron and calcium dysregulation.
ER -
TY - JOUR
AU - Inostroza, N.
AU - Mendizabal, F.
AU - Arratia-P, R., R.
AU - Orellana, C.
AU - Linares-Flores, C.
T1 - Improvement of Photovoltaic Performance by Substituent Effect of Donor and Acceptor Structure of Tpa-Based Dye-Sensitized Solar Cells
JO - Journal of Molecular Modeling
PY - 2016/
VL - 22
IS - 1
SP -
EP -
UR - /brokenurl#://WOS:000369312100025
DO - 10.1007/s00894-015-2893-9
KW - absorption
KW - alignment
KW -
KW - approximation
KW -
KW - cells
KW -
KW - density
KW - design
KW -
KW - dqcauchile
KW - dye-sensitized
KW - electron-transfer
KW -
KW - electronic
KW - energy-levels
KW -
KW - free
KW - functional
KW - molecular
KW - organic
KW - organic-dyes
KW -
KW - porphyrins
KW -
KW - semiconductor
KW -
KW - solar
KW - spectra
KW -
KW - surface
KW - theory
KW -
KW - tio2
L1 -
SN -
N1 -
N1 -
AB - We report a computational study of a series of organic dyes built with triphenylamine (TPA) as an electron donor group. We designed a set of six dyes called (TPA-n, where n=0-5). In order to enhance the electron-injection process, the electron-donor effect of some specific substituent was studied. Thus, we gave insights into the rational design of organic TPA-based chromophores for use in dye-sensitized solar cells (DSSCs). In addition, we report the HOMO, LUMO, the calculated excited state oxidized potential E-dye*(eV) and the free energy change for electron-injection Delta G(inject)(eV), and the UV-visible absorption bands for TPA-n dyes by a time-dependent density functional theory (TDDFT) procedure at the B3LYP and CAM-B3LYP levels with solvent effect. The results demonstrate that the introduction of the electron-acceptor groups produces an intramolecular charge transfer showing a shift of the absorption wavelengths of TPA-n under studies.
ER -
TY - JOUR
AU - Reineck, Philipp
T1 - Plasmonic Hot Electron Solar Cells: The Effect of Nanoparticle Size on Quantum Efficiency
JO -
PY - 2016/
VL -
IS -
SP -
EP -
UR -
DO -
KW - Cells
KW -
KW - Efficiency
KW - Electron
KW - Hot
KW - Nanoparticle
KW - Plasmonic
KW - Quantum
KW - Size
KW -
KW - Solar
L1 -
SN -
N1 -
N1 -
AB -
ER -
TY - JOUR
AU - Urra, F.A.
AU - Weiss-Lopez, B.
AU - Araya-Maturana, R.
T1 - Determinants of Anti-Cancer Effect of Mitochondrial Electron Transport Chain Inhibitors: Bioenergetic Profile and Metabolic Flexibility of Cancer Cells
JO - Current Pharmaceutical Design
PY - 2016/
VL - 22
IS - 39
SP - 5998
EP - 6008
UR - /brokenurl#://WOS:000390650400011
DO - 10.2174/1381612822666160719122626
KW - agents
KW -
KW - alpha-ketoglutarate
KW -
KW - anti-cancer
KW - cancer
KW - carboxylation
KW -
KW - cells
KW -
KW - complex-i
KW -
KW - complexes
KW -
KW - dqcauchile
KW - glutamine
KW - glutamine-metabolism
KW -
KW - impairment
KW -
KW - metabolic
KW - metabolism
KW -
KW - mitochondrial
KW - nadh-ubiquinone
KW - ovarian-cancer
KW -
KW - oxidative
KW - oxidative-phosphorylation
KW -
KW - oxidoreductase
KW -
KW - pancreatic-cancer
KW -
KW - phosphorylation
KW -
KW - reductive
KW - remodeling
KW -
KW - respiratory
KW - respiratory-chain
KW -
KW - slow-cycling
KW - solid
KW - tumor-cells
KW -
KW - tumors
L1 -
SN -
N1 -
N1 -
AB - Recent evidence highlights that energy requirements of cancer cells vary greatly from normal cells and they exhibit different metabolic phenotypes with variable participation of both glycolysis and oxidative phosphorylation (OXPHOS). Interestingly, mitochondrial electron transport chain (ETC) has been identified as an essential component in bioenergetics, biosynthesis and redox control during proliferation and metastasis of cancer cells. This dependence converts ETC of cancer cells in a promising target to design small molecules with anti-cancer actions. Several small molecules have been described as ETC inhibitors with different consequences on mitochondrial bioenergetics, viability and proliferation of cancer cells, when the substrate availability is controlled to favor either the glycolytic or OXPHOS pathway. These ETC inhibitors can be grouped as 1) inhibitors of a respiratory complex (e.g. rotenoids, vanilloids, alkaloids, biguanides and polyphenols), 2) inhibitors of several respiratory complexes (e.g. capsaicin, ME-344 and epigallocatechin-3 gallate) and 3) inhibitors of ETC activity (e.g. elesclomol and VLX600). Although pharmacological ETC inhibition may produce cell death and a decrease of proliferation of cancer cells, factors such as degree of inhibition of ETC activity by small molecules, bioenergetic profile and metabolic flexibility of different cancer types or subpopulations of cells in a particular cancer type, can affect the impact of the anti-cancer actions. Particularly interesting are the adaptive mechanisms induced by ETC inhibition, such as induction of glutamine-dependent reductive carboxylation, which may offer a strategy to sensitize cancer cells to inhibitors of glutamine metabolism.
ER -
TY - JOUR
AU - Urra, F.A.
AU - Cordova-Delgado, M.
AU - Lapier, M.
AU - Orellana-Manzano, A.
AU - Acevedo-Arevalo, L.
AU - Pessoa-Mahana, H.
AU - Gonzalez-Vivanco, J.M.
AU - Martinez-Cifuentes, M.
AU - Ramirez-Rodriguez, O.
AU - Millas-Vargas, J.P.
AU - Weiss-Lopez, B.
AU - Pavani, M.
AU - Ferreira, J.
AU - Araya-Maturana, R.
T1 - Small Structural Changes on a Hydroquinone Scaffold Determine the Complex I Inhibition or Uncoupling of Tumoral Oxidative Phosphorylation
JO - Toxicology and Applied Pharmacology
PY - 2016/
VL - 291
IS -
SP - 46
EP - 57
UR - /brokenurl#://WOS:000378100100006
DO - 10.1016/j.taap.2015.12.005
KW - 6-ketocholestanol
KW - adenocarcinoma
KW - agents
KW -
KW - anti-cancer
KW - apoptosis
KW -
KW - calu-6
KW - cancer-cells
KW -
KW - cell
KW - cells
KW -
KW - complex
KW - derivatives
KW -
KW - dqcauchile
KW - dysfunction
KW -
KW - energy-metabolism
KW -
KW - hydroquinones
KW -
KW - i
KW -
KW - liver-mitochondria
KW -
KW - mitochondrial
KW - oxidative
KW - phosphorylation
KW -
KW - respiration
KW -
KW - ta3
KW -
KW - uncouplers
L1 -
SN -
N1 -
N1 -
AB - Mitochondria participate in several distinctiveness of cancer cell, being a promising target for the design of anti-cancer compounds. Previously, we described that ortho-carbonyl hydroquinone scaffold 14 inhibits the complex I-dependent respiration with selective anti-proliferative effect on mouse mammary adenocarcinoma TA3/Ha cancer cells; however, the structural requirements of this hydroquinone scaffold to affect the oxidative phosphorylation (OXPHOS) of cancer cells have not been studied in detail. Here, we characterize the mitochondrial metabolism of TA3/Ha cancer cells, which exhibit a high oxidative metabolism, and evaluate the effect of small structural changes of the hydroquinone scaffold 14 on the respiration of this cell line. Our results indicate that these structural changes modify the effect on OXPHOS, obtaining compounds with three alternative actions: inhibitors of complex I-dependent respiration, uncoupler of OXPHOS and compounds with both actions. To confirm this, the effect of a bicyclic hydroquinone (9) was evaluated in isolated mitochondria. Hydroquinone 9 increased mitochondrial respiration in state 4o without effects on the ADP-stimulated respiration (state 3(ADP)), decreasing the complexes I and II-dependent respiratory control ratio. The effect on mitochondrial respiration was reversed by 6-ketocholestanol addition, indicating that this hydroquinone is a protonophoric uncoupling agent. In intact TA3/Ha cells, hydroquinone 9 caused mitochondrial depolarization, decreasing intracellular ATP and NAD(P)H levels and GSH/GSSG ratio, and slightly increasing the ROS levels. Moreover, it exhibited selective NAD(P)H availability-dependent anti-proliferative effect on cancer cells. Therefore, our results indicate that the ortho-carbonyl hydroquinone scaffold offers the possibility to design compounds with specific actions on OXPHOS of cancer cells.
ER -
TY - JOUR
AU - Tambe, Dhananjay T.
AU - Fredberg, Jeffrey J.
T1 - And I hope you like jamming too
JO - New Journal of Physics
PY - 2015/10
VL - 17
IS - 9
SP -
EP -
UR - http://dx.doi.org/10.1088/1367-2630/17/9/091001
DO - 10.1088/1367-2630/17/9/091001
KW - cancer
KW -
KW - cells
KW -
KW - jamming
L1 -
SN -
N1 -
N1 -
AB -
ER -
TY - JOUR
AU - Garcia-Beltran, O.
AU - Mena, N.
AU - Yanez, O.
AU - Caballero, J.
AU - Vargas, V.
AU - Nunez, M.T.
AU - Cassels, B.K.
T1 - Design, Synthesis and Cellular Dynamics Studies in Membranes of a New Coumarin-Based "Turn-Off" Fluorescent Probe Selective for Fe2+
JO - European Journal of Medicinal Chemistry
PY - 2013/
VL - 67
IS -
SP - 60
EP - 63
UR - /brokenurl#://WOS:000325121800007
DO - 10.1016/j.ejmech.2013.06.022
KW - cells
KW -
KW - chelatable
KW - chelators
KW -
KW - chemosensor
KW -
KW - deficiency
KW -
KW - dqcauchile
KW - dynamics
KW -
KW - fe2+
KW - fe3+
KW - fluorescent
KW - ion
KW -
KW - iron
KW -
KW - labile
KW - molecular
KW - probes
KW -
KW - sensor
KW -
KW - turn-off
L1 -
SN -
N1 -
N1 -
AB - A new coumarin-based 'turn-off' fluorescent probe, 7-(diethylamino)-N-(1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)-2-oxo-2H-chromene-3-carboxamide (AGD) was synthesized. This compound is highly selective for ferrous ions (Fe2+) and can reversibly detect them in aqueous medium. The probe localizes to the cell membrane in living cells, where it can detect changes in Fe2+ concentration. Molecular dynamics (MD) simulations indicate that AGD interacts with the lipid bilayer at the level of the glycerol moieties.
ER -
TY - JOUR
AU - Ortlepp, Claudia
AU - Steudel, Christine
AU - Heiderich, Caroline
AU - Koch, Sina
AU - Jacobi, Angela
AU - Ryser, Martin
AU - Brenner, Sebastian
AU - Bornhäuser, Martin
AU - Brors, Benedikt
AU - Hofmann, Wolf-Karsten
AU - Ehninger, Gerhard
AU - Thiede, Christian
T1 - Autotaxin is expressed in FLT3-ITD positive acute myeloid leukemia and hematopoietic stem cells and promotes cell migration and proliferation.
JO - Exp Hematol
PY - 2013/05
VL - 41
IS - 5
SP - 444
EP - 461.e4
UR - http://dx.doi.org/10.1016/j.exphem.2013.01.007
DO - 10.1016/j.exphem.2013.01.007
KW - /&/
KW - 3
KW -
KW - Acute
KW - Analysis;
KW - Array
KW - Blotting
KW -
KW - Cell
KW - Cells
KW -
KW - Cells;
KW - Chain
KW - Cultured;
KW - Diester
KW - Disease;
KW - Expression
KW - Gene
KW - Hematopoietic
KW - Humans;
KW - Hydrolases
KW -
KW - Indoles
KW -
KW - Inhibitors
KW -
KW - K562
KW - Kinase
KW - Leukemia
KW -
KW - Leukemic
KW -
KW - Line
KW -
KW - Line;
KW - Lysophosphatidylcholines
KW -
KW - Lysophospholipids
KW -
KW - Movement
KW -
KW - Mutation;
KW - Myeloid
KW -
KW - Oligonucleotide
KW - Phosphoric
KW - Polymerase
KW - Profiling;
KW - Proliferation;
KW - Protein
KW - Reaction;
KW - Regulation
KW -
KW - Repeat
KW - Reverse
KW - Sequence
KW - Sequences
KW -
KW - Staurosporine
KW -
KW - Stem
KW - Tandem
KW - Transcriptase
KW - Tumor;
KW - Tyrosine
KW - Western;
KW - analogs
KW - derivatives/pharmacology;
KW - drug
KW - effects/genetics;
KW - effects;
KW - fms-Like
KW - genetics
KW - genetics/metabolism/pathology;
KW - genetics/metabolism;
KW - genetics;
KW - metabolism/pharmacology;
KW - metabolism;
KW - pharmacology;
L1 -
SN -
N1 -
N1 -
AB - Autotaxin (ATX) has been reported to act as a motility and growth factor in a variety of cancer cells. The ATX protein acts as a secreted lysophospholipase D by converting lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), which signals via G-protein-coupled receptors and has important functions in cell migration and proliferation. This study demonstrates that ATX expression is specifically upregulated and functionally active in acute myeloid leukemia (AML) harboring an internal tandem duplication (ITD) mutation of the FLT3 receptor gene. Moreover, ATX expression was also found in normal human CD34+ progenitor cells and selected myeloid and lymphoid subpopulations. Enforced expression of mutant FLT3-ITD by retroviral vector transduction increased ATX mRNA in selected cell lines, whereas inhibition of FLT3-ITD signaling by sublethal doses of PKC412 or SU5614 led to a significant downregulation of ATX mRNA and protein levels. In the presence of LPC, ATX expression significantly increased proliferation. LPA induced proliferation, regardless of ATX expression, and induced chemotaxis in all tested human leukemic cell lines and human CD34(+) progenitors. LPC increased chemotaxis only in cells with high expression of endogenous ATX by at least 80 demonstrating the autocrine action of ATX. Inhibition of ATX using a small molecule inhibitor selectively induced killing of ATX-expressing cell lines and reduced motility in these cells. Our data suggest that the production of bioactive LPA through ATX is involved in controlling proliferation and migration during hematopoiesis and that deregulation of ATX contributes to the pathogenesis of AML.
ER -
TY - JOUR
AU - Pinto, Sheena
AU - Michel, Chloé
AU - Schmidt-Glenewinkel, Hannah
AU - Harder, Nathalie
AU - Rohr, Karl
AU - Wild, Stefan
AU - Brors, Benedikt
AU - Kyewski, Bruno
T1 - Overlapping gene coexpression patterns in human medullary thymic epithelial cells generate self-antigen diversity.
JO - Proc Natl Acad Sci U S A
PY - 2013/10
VL - 110
IS - 37
SP - E3497
EP - E3505
UR - http://dx.doi.org/10.1073/pnas.1308311110
DO - 10.1073/pnas.1308311110
KW - Antigenic
KW - Autoantigens
KW -
KW - Cell
KW - Cells
KW -
KW - Differentiation
KW -
KW - Epithelial
KW - Expression;
KW - Family;
KW - Gene
KW - Gland
KW -
KW - Humans;
KW - Multigene
KW - Self
KW - Thymus
KW - Tolerance
KW -
KW - Variation;
KW - classification/cytology/immunology;
KW - cytology/immunology
KW - genetics/immunology;
KW - genetics;
L1 -
SN -
N1 -
N1 -
AB - Promiscuous expression of numerous tissue-restricted self-antigens (TRAs) in medullary thymic epithelial cells (mTECs) is essential to safeguard self-tolerance. A distinct feature of promiscuous gene expression is its mosaic pattern (i.e., at a given time, each self-antigen is expressed only in 1-3% of mTECs). How this mosaic pattern is generated at the single-cell level is currently not understood. Here, we show that subsets of human mTECs expressing a particular TRA coexpress distinct sets of genes. We identified three coexpression groups comprising overlapping and complementary gene sets, which preferentially mapped to certain chromosomes and intrachromosomal gene clusters. Coexpressed gene loci tended to colocalize to the same nuclear subdomain. The TRA subsets aligned along progressive differentiation stages within the mature mTEC subset and, in vitro, interconverted along this sequence. Our data suggest that single mTECs shift through distinct gene pools, thus scanning a sizeable fraction of the overall repertoire of promiscuously expressed self-antigens. These findings have implications for the temporal and spatial (re)presentation of self-antigens in the medulla in the context of tolerance induction.
ER -
TY - JOUR
AU - Urra, F.A.
AU - Cordova-Delgado, M.
AU - Pessoa-Mahana, H.
AU - Ramirez-Rodriguez, O.
AU - Weiss-Lopez, B.
AU - Ferreira, J.
AU - Araya-Maturana, R.
T1 - Mitochondria: A Promising Target for Anticancer Alkaloids
JO - Current Topics in Medicinal Chemistry
PY - 2013/
VL - 13
IS - 17
SP - 2171
EP - 2183
UR - /brokenurl#://WOS:000324801300007
DO -
KW - 2
KW -
KW - active
KW - agent
KW -
KW - alkaloids
KW -
KW - apoptosis
KW -
KW - cancer
KW - capsaicin
KW - carbazole
KW - caspase-dependent
KW - cells
KW -
KW - delivery
KW -
KW - dqcauchile
KW - endoplasmic
KW - endoplasmic-reticulum
KW - hepatocellular-carcinoma
KW -
KW - human
KW - induces
KW - melanoma-cells
KW - microtubule-modulating
KW - mitochondria
KW -
KW - mouse
KW - nucleotide
KW - peptide
KW -
KW - prostate-cancer
KW - reticulum
KW -
KW - self-assembling
KW - stress
KW -
KW - targeting
KW -
KW - translocase
L1 -
SN -
N1 -
N1 -
AB - A great number of alkaloids exhibit high potential in cancer research. Some of them are anticancer drugs with well-defined clinical uses, exerting their action on microtubules dynamics or DNA replication and topology. On the other hand, mitochondria have been recognized as an essential organelle in the establishment of tumor characteristics, especially the resistance to cell death, high proliferative capacity and adaptation to unfavorable cellular environment. Interestingly, many alkaloids exert their anticancer activities affecting selectively some functions of the tumor mitochondria by 1) modulating OXPHOS and ADP/ATP transport, 2) increasing ROS levels and mitochondrial potential dissipation by crosstalk between endoplasmic reticulum (ER) and mitochondria, 3) inducing mitochondria-dependent apoptosis and autophagy, 4) inhibiting mitochondrial metabolic pathways and 5) by alteration of the morphology and biogenesis of this organelle. These antecedents show the relevance of developing research about the effects of alkaloids on functions controlled by tumor mitochondria, offering an attractive target for the design of new alkaloid derivatives, considering organelle-specific delivery strategies. This review describes mitochondria as a central component in the anticancer action of a set of alkaloids, in a way to illustrate the importance of this organelle in medicinal chemistry.
ER -
TY - JOUR
AU - Donovan, Graham M.
AU - Lythe, Grant
T1 - T-cell movement on the reticular network
JO - Journal of Theoretical Biology
PY - 2012/02
VL - 295
IS -
SP - 59
EP - 67
UR - http://dx.doi.org/10.1016/j.jtbi.2011.11.001
DO - 10.1016/j.jtbi.2011.11.001
KW - brownianmotion
KW -
KW - cells
KW -
KW - spatial-networks
KW - biological-networks
KW - diffusion
L1 -
SN -
N1 -
N1 -
AB - The idea that the apparently random motion of T cells in lymph nodes is a result of movement on a reticular network (RN) has received support from dynamic imaging experiments and theoretical studies. We present a mathematical representation of the RN consisting of edges connecting vertices that are randomly distributed in three-dimensional space, and models of lymphocyte movement on such networks including constant speed motion along edges and Brownian motion, not in three-dimensional, but only along edges. The simplest model, in which a cell moves with a constant speed along edges, is consistent with mean-squared displacement proportional to time over intervals long enough to include several changes of direction. A non-random distribution of turning angles is one consequence of motion on a preformed network. Confining cell movement to a network does not, in itself, increase the frequency of cell–cell encounters.
ER -
TY - JOUR
AU - Gamba, Andrea
AU - Nicodemi, Mario
AU - Soriano, Jordi
AU - Ott, Albrecht
T1 - Critical Behavior and Axis Defining Symmetry Breaking in Hydra Embryonic Development
JO - Physical Review Letters
PY - 2012/04
VL - 108
IS -
SP -
EP -
UR - http://dx.doi.org/10.1103/physrevlett.108.158103
DO - 10.1103/physrevlett.108.158103
KW - cells
KW -
KW - embryonic-development
KW -
KW - latticemodel
KW - critical-phenomena
L1 -
SN -
N1 -
N1 -
AB - The formation of a hollow cellular sphere is often one of the first steps of multicellular embryonic development. In the case of Hydra, the sphere breaks its initial symmetry to form a foot-head axis. During this process a gene, ks1, is increasingly expressed in localized cell domains whose size distribution becomes scale-free at the axis-locking moment. We show that a physical model based solely on the production and exchange of ks1-promoting factors among neighboring cells robustly reproduces the scaling behavior as well as the experimentally observed spontaneous and temperature-directed symmetry breaking.
ER -
TY - JOUR
AU - Westermann, Frank
AU - Muth, Daniel
AU - Benner, Axel
AU - Bauer, Tobias
AU - Henrich, Kai-Oliver
AU - Oberthuer, André
AU - Brors, Benedikt
AU - Beissbarth, Tim
AU - Vandesompele, Jo
AU - Pattyn, Filip
AU - Hero, Barbara
AU - König, Rainer
AU - Fischer, Matthias
AU - Schwab, Manfred
T1 - Distinct transcriptional MYCN/c-MYC activities are associated with spontaneous regression or malignant progression in neuroblastomas.
JO - Genome Biol
PY - 2008/
VL - 9
IS - 10
SP -
EP -
UR - http://dx.doi.org/10.1186/gb-2008-9-10-r150
DO - 10.1186/gb-2008-9-10-r150
KW - Analysis;
KW - Cells
KW -
KW - Cultured
KW - Disease
KW - Expression
KW - Gene
KW - Genes
KW -
KW - Genetic;
KW - Neoplastic;
KW - Neuroblastoma
KW -
KW - Nuclear
KW - Oncogene
KW - Progression;
KW - Proteins
KW - Proteins
KW -
KW - Proto-Oncogene
KW - Regulation
KW -
KW - Survival
KW - Transcription
KW -
KW - Tumor
KW - c-myc
KW -
KW - genetics/metabolism;
KW - genetics/pathology;
KW - myc;
L1 -
SN -
N1 -
N1 -
AB - Amplified MYCN oncogene resulting in deregulated MYCN transcriptional activity is observed in 20% of neuroblastomas and identifies a highly aggressive subtype. In MYCN single-copy neuroblastomas, elevated MYCN mRNA and protein levels are paradoxically associated with a more favorable clinical phenotype, including disseminated tumors that subsequently regress spontaneously (stage 4s-non-amplified). In this study, we asked whether distinct transcriptional MYCN or c-MYC activities are associated with specific neuroblastoma phenotypes.We defined a core set of direct MYCN/c-MYC target genes by applying gene expression profiling and chromatin immunoprecipitation (ChIP, ChIP-chip) in neuroblastoma cells that allow conditional regulation of MYCN and c-MYC. Their transcript levels were analyzed in 251 primary neuroblastomas. Compared to localized-non-amplified neuroblastomas, MYCN/c-MYC target gene expression gradually increases from stage 4s-non-amplified through stage 4-non-amplified to MYCN amplified tumors. This was associated with MYCN activation in stage 4s-non-amplified and predominantly c-MYC activation in stage 4-non-amplified tumors. A defined set of MYCN/c-MYC target genes was induced in stage 4-non-amplified but not in stage 4s-non-amplified neuroblastomas. In line with this, high expression of a subset of MYCN/c-MYC target genes identifies a patient subtype with poor overall survival independent of the established risk markers amplified MYCN, disease stage, and age at diagnosis.High MYCN/c-MYC target gene expression is a hallmark of malignant neuroblastoma progression, which is predominantly driven by c-MYC in stage 4-non-amplified tumors. In contrast, moderate MYCN function gain in stage 4s-non-amplified tumors induces only a restricted set of target genes that is still compatible with spontaneous regression.
ER -
TY - JOUR
AU - Haas, D.
AU - Morgenthaler, J.
AU - Lacbawan, F.
AU - Long, B.
AU - Runz, H.
AU - Garbade, S. F.
AU - Zschocke, J.
AU - Kelley, R. I.
AU - Okun, J. G.
AU - Hoffmann, G. F.
AU - Muenke, M.
T1 - Abnormal sterol metabolism in holoprosencephaly: studies in cultured lymphoblasts.
JO - J Med Genet
PY - 2007/05
VL - 44
IS - 5
SP - 298
EP - 305
UR - http://dx.doi.org/10.1136/jmg.2006.047258
DO - 10.1136/jmg.2006.047258
KW - /&/
KW - Acetates
KW -
KW - Adult;
KW - Carbon
KW - Cells
KW -
KW - Chemicals
KW -
KW - Child
KW -
KW - Cholesterol
KW -
KW - Chromatography-Mass
KW - Cultured;
KW - Female;
KW - Gas
KW - Holoprosencephaly
KW -
KW - Humans;
KW - Infant
KW -
KW - Infant;
KW - Lymphocytes
KW -
KW - Male;
KW - Newborn;
KW - Organic
KW - Preschool;
KW - Radioisotopes;
KW - Reference
KW - Solvents
KW -
KW - Spectrometry;
KW - Standards;
KW - Sterols
KW -
KW - biosynthesis;
KW - isolation
KW - metabolism;
KW - purification/metabolism
KW - sfg
L1 -
SN -
N1 -
N1 -
AB - BACKGROUND: Holoprosencephaly (HPE) is the most common
structural malformation of the developing forebrain in
humans. The aetiology is heterogeneous and remains
unexplained in approximately 75% of patients. OBJECTIVE:
To examine cholesterol biosynthesis in lymphoblastoid cell
lines of 228 patients with HPE, since perturbations of
cholesterol homeostasis are an important model system to
study HPE pathogenesis in animals. METHODS: An in vitro
loading test that clearly identifies abnormal increase of
C27 sterols in lymphoblast-derived cells was developed
using [2-(14)C] acetate as substrate. RESULTS: 22 (9.6
HPE cell lines had abnormal sterol pattern in the in vitro
loading test. In one previously reported patient,
Smith-Lemli-Opitz syndrome was diagnosed, whereas others
also had clearly reduced cholesterol biosynthesis of
uncertain cause. The mean (SD) cholesterol levels were 57p> (15.3 and 82% (4.7 of total sterols in these cell
lines and controls, respectively. The pattern of
accumulating sterols was different from known defects of
cholesterol biosynthesis. In six patients with abnormal
lymphoblast cholesterol metabolism, additional mutations in
genes known to be associated with HPE or chromosomal
abnormalities were observed. CONCLUSIONS: Impaired
cholesterol biosynthesis may be a contributing factor in
the cause of HPE and should be considered in the evaluation
of causes of HPE, even if mutations in HPE-associated genes
have already been found.
ER -
TY - CONF
AU - Pandey, S.
AU - Bortei-Doku, A.
AU - White, M.H.
A2 -
T1 - Molecular Dynamics of Biological Ion Channels
T2 - 2005 International Semiconductor Device Research Symposium
PB - IEEE
C1 -
PY - 2005/12
VL -
IS -
SP - 310
EP - 311
UR - https://ieeexplore.ieee.org/document/1596110
DO - 10.1109/ISDRS.2005.1596110
KW - (biology)
KW -
KW - Analytical
KW - Biological
KW - Biomembranes
KW -
KW - CMOS
KW - Cells
KW - Drugs
KW -
KW - Fluctuations
KW -
KW - Green
KW - Laplace
KW - Nanoelectronics
KW - cells
KW -
KW - equations
KW -
KW - function
KW -
KW - models
KW -
KW - myown
KW - technology
L1 -
SN -
N1 -
N1 -
AB - Ion channels are pores through a cell membrane that allow the exchange of specific ions across them. Understanding the atomistic-level ionic flow through these biological channels is crucial for pharmacology and drug discovery. In addition, the marriage of biological cells and nanoelectronics offers the possibility of new devices with the potential to go beyond the limitations of CMOS technology. The study of ion channels is needed to model the interface between nanoelectronics and biological cells. Till recently, theoretical analysis of ion transport has been limited to low-resolution continuum diffusion-based or kinetic-based models. Such analytical models fail to include the factors affecting the ionic conduction through ion channels. In this paper, an electro-diffusion model is presented which extends previous models to incorporate the effects of electric field, energy barrier, and rate-limited association/dissociation of ions with protein charges inside the channel. We derive the probability density function (p.d.f.), the correlation function, and the spectral density of ion number fluctuation.
ER -
TY - JOUR
AU - Stelling, Jörg
AU - Sauer, Uwe
AU - Szallasi, Zoltan
AU - Doyle, Francis J.
AU - Doyle, John
T1 - Robustness of Cellular Functions
JO - Cell
PY - 2004/10
VL - 118
IS - 6
SP - 675
EP - 685
UR - http://dx.doi.org/10.1016/j.cell.2004.09.008
DO - 10.1016/j.cell.2004.09.008
KW - cells
KW -
KW - resilience
KW -
KW - review
L1 -
SN -
N1 -
N1 -
AB - Robustness, the ability to maintain performance in the face of perturbations and uncertainty, is a long-recognized key property of living systems. Owing to intimate links to cellular complexity, however, its molecular and cellular basis has only recently begun to be understood. Theoretical approaches to complex engineered systems can provide guidelines for investigating cellular robustness because biology and engineering employ a common set of basic mechanisms in different combinations. Robustness may be a key to understanding cellular complexity, elucidating design principles, and fostering closer interactions between experimentation and theory.
ER -
TY - JOUR
AU - Luo, Paifeng
AU - Xia, Wei
AU - Zhou, Shengwen
AU - Sun, Lin
AU - Cheng, Jigui
AU - Xu, Chenxi
AU - Lu, Yingwei
T1 - Solvent Engineering for Ambient-Air-Processed, Phase-Stable CsPbI3 in Perovskite Solar Cells
JO - The Journal of Physical Chemistry Letters
PY - 0/
VL - 0
IS - 0
SP - 3603
EP - 3608
UR - http://dx.doi.org/10.1021/acs.jpclett.6b01576
DO - 10.1021/acs.jpclett.6b01576
KW - Ambient-Air-Processed
KW -
KW - Cells
KW -
KW - CsPbI3
KW -
KW - Engineering
KW - Perovskite
KW - Solar
KW - Solvent
L1 -
SN -
N1 -
N1 -
AB - Inorganic CsPbI3 perovskite solar cells (PSCs) owning comparable photovoltaic performance and enhanced thermal stability compared to organic–inorganic hybrid perovskites have attracted enormous interest in the past year. However, it is still a challenge to stabilize the desired black α-CsPbI3 perovskites in ambient air for photovoltaic applications. Herein, sequential solvent engineering including the addition of hydroiodic acid (HI) and subsequent isopropanol (IPA) treatment for fabricating stable and working CsPbI3 PSCs is developed, and a novel low-temperature phase-transition route from new intermediate Cs4PbI6 to stable α-CsPbI3 is also released for the first time. As such, the as-prepared PSCs give a relatively high power conversion efficiency (PCE) of 4.13% (reverse scan), and the steady-state power output of 1.88% is confirmed for the selected cell with an initial PCE of 3.13 To the best of our knowledge, this is the first demonstration of fabricating CsPbI3 inorganic PSCs under fully open-air conditions.
ER -