Thus, Th17 cells can promote humoral autoirnmunity via a novel mechanism that involves CCL2.”
“Aims: A bridging ligand 2,4,6-pyridine tricarboxylic acid (H(3)ptc) and its manganese(II) complex [Mn(Hptc)(phen)(OH)]n(Hptc = 2,4,6-pyridine tricarboxylic acid, phen = 1,10-phenanthroline) have been synthesized and characterized.\n\nMain methods: The interaction with DNA (HeLa and KB) was carried out by fluorescence
spectrum and gel electrophoresis assay. Adriamycin In vitro apoptosis assay and cytotoxicity assay detect the manganese (II) complex interaction with cancer cells.\n\nKey findings: Fluorescence spectrum demonstrated the ability of the complexes to interact with DNA in an intercalative mode. Gel electrophoresis assay exhibited more effective DNA-cleavage activity. In vitro apoptosis assay of the complexes were examined on HeLa and KB cells, exhibited cytotoxic specificity and a significant cancer cell inhibitory rate.\n\nSignificance: The complex may be a latent antitumor agent as a result of its unique interaction mode with DNA and cancer cells inhibition effect. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.”
“Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation
for extended time periods after the signal appears, proliferating click here Fludarabine datasheet through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A,
which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression.