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Cells Regardless (cell + regardless)
Selected AbstractsRole of ISGF3 in modulating the anti-hepatitis B virus activity of interferon-alpha in vitroJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2008Quan Zhang Abstract Background and Aim:, Although interferon-, (IFN-,) is an effective treatment for hepatitis B virus (HBV) infection, its precise mechanism of action has not been identified. In this study, we investigated the role of signal transduction pathways in the activation of anti-HBV responses mediated by IFN-,. Methods:, Using an oligo microarray, we found that four genes in the IFN-, signal pathway were markedly upregulated by IFN-, in human hepatoma cells regardless of whether they had been transfected with a plasmid containing the HBV genome: signal transducers and activators of transcription 1 (STAT1), interferon regulatory factor-9 (IRF-9, also called ISGF3, or P48), IFN-,-inducible protein 15 (IFI-15) and IFN-,-inducible protein 6,16 (IFI-6-16). We also investigated the role of IFN-stimulated gene factor3 (ISGF3) complex in IFN-,-mediated anti-HBV responses in human hepatoma cells by measuring the mRNA of the three genes within ISGF3 (STAT1, STAT2 and IRF-9) using semiquantitative reverse-transcription PCR (RT-PCR), and expression of the three proteins by western blot, and the mRNA and protein of dsRNA-dependent protein kinase (PKR). Results:, STAT1, STAT2, IRF-9 and PKR mRNA as well as protein levels were upregulated by IFN-, treatment. When cells were pretreated with genistein, STAT1, STAT2 and IRF-9 mRNA levels remained unchanged after IFN-, stimulation, but PKR mRNA levels decreased, and the expression of the STAT1, P-STAT2, IRF-9 and PKR proteins decreased. Levels of HBV DNA decreased in the supernatants of cells treated with IFN-,, while ISGF3 levels increased. The quantity of HBV DNA remained unchanged by pretreating with genistein. Conclusions:, These observations suggested that the Janus tyrosine kinase,STAT (JAK-STAT) pathway may play a major role in mediating the effects of IFN-, against HBV, and that ISGF3 might be a key factor. [source] Electrophysiological characterization of neural stem/progenitor cells during in vitro differentiation: Study with an immortalized neuroectodermal cell lineJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2007M. Jelitai Abstract Despite the accumulating data on the molecular and cell biological characteristics of neural stem/progenitor cells, their electrophysiological properties are not well understood. In the present work, changes in the membrane properties and current profiles were investigated in the course of in vitro-induced neuron formation in NE-4C cells. Induction by retinoic acid resulted in neuronal differentiation of about 50% of cells. Voltage-dependent Na+ currents appeared early in neuronal commitment, often preceding any morphological changes. A-type K+ currents were detected only at the stage of network formation by neuronal processes. Flat, epithelial- like, nestin-expressing progenitors persisted beside differentiated neurons and astrocytes. Stem/progenitor cells were gap junction coupled and displayed large, symmetrical, voltage-independent currents. By the blocking of gap junction communication, voltage-independent conductance was significantly reduced, and delayed-rectifying K+ currents became detectable. Our data indicate that voltage-independent symmetrical currents and gap junction coupling are characteristic physiological features of neural stem and progenitor cells regardless of the developmental state of their cellular environment. © 2007 Wiley-Liss, Inc. [source] Human embryonic stem cell-derived neural precursors develop into neurons and integrate into the host brainJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2006Daniel J. Guillaume Abstract Whether and how in-vitro-produced human neural precursors mature and integrate into the brain are crucial to the utility of human embryonic stem (hES) cells in treating neurological disorders. After transplantation into the ventricles of neonatal immune-deficient mice, hES-cell-derived neural precursors stopped expressing the cell division marker Ki67, except in neurogenic areas, and differentiated into neurons and then glia in a temporal course intrinsic to that of human cells regardless of location. The human cells located in the gray matter became neurons in the olfactory bulb and striatum, whereas those in the white matter produced exclusively glia. Importantly, the grafted human cells formed synapses. Thus, the in-vitro-produced human neural precursors follow their intrinsic temporal program to produce neurons and glia and, in response to environmental signals, generate cells appropriate to their target regions and integrate into the brain. © 2006 Wiley-Liss, Inc. [source] Comparison of articular and auricular cartilage as a cell source for the autologous chondrocyte implantationJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2009Elvira Mali Abstract Articular (medial femoral condyle) and auricular cartilage (anithelix) was compared as a cell source for the autologous joint repair. Cells isolated from five human cadaveric donors were cultured parallel in the monolayer cultures and in the 3D alginate hydrogel constructs for 1 week. Cell morphology was controlled by the fluorescent microscopy and gene expressions of type I collagen (COL1), type II collagen (COL2), aggrecan (AGR), versican (VER), and elastin (ELS) were analyzed by the real-time polymerase chain reaction. COL1 and ELS, predominant in the phenotype of auricular biopsy, were statistically lower in the articular biopsies. Even though COL2 and AGR decreased in monolayers of both cell sources, the dedifferentiation process affected auricular cells intensely. Cells embedded in the alginate hydrogel directly after the isolation did not exhibit the dedifferentiated phenotype. Additionally, COL1, COL2, AGR, and VER were comparable between the two sources. ELS however, remained higher in the auricular cells regardless of the culture type. The study indicates that auricular chondrocytes cultured in a 3D environment immediately after the isolation have a neo-cartilage potential for the articular surface reconstruction. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 943,948, 2009 [source] | ||||||||||