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Undifferentiated PC12 Cells (undifferentiated + pc12_cell)
Selected AbstractsCREB-dependent Nur77 induction following depolarization in PC12 cells and neurons is modulated by MEF2 transcription factorsJOURNAL OF NEUROCHEMISTRY, Issue 4 2010Brian Yee Hong Lam J. Neurochem. (2010) 112, 1065,1073. Abstract Expression of the nuclear orphan receptor gene Nur77 in neuronal cells is induced by activity-dependent increases in intracellular Ca2+ ions. Ca2+ responsiveness of the Nur77 gene has been attributed to two distinct DNA regulatory regions that recruit the transcription factors cAMP response element binding protein (CREB) and myocyte enhancer factor-2 (MEF2). Here we used dominant interfering and constitutively active mutants of CREB and MEF2 proteins to assess their relative contribution to depolarization-induced Nur77 expression in undifferentiated PC12 cells and hippocampal neurons. We show that while CREB is necessary for Ca2+ -activated Nur77 expression MEF2 functions to modulate CREB-dependent Nur77 expression by acting as a repressor in quiescent cells. [source] Integrin ,3,1 interacts with I1PP2A/lanp and phosphatase PP1JOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2006Diana Mutz Abstract Integrin ,3,1 is a receptor for the extracellular matrix component laminin 5. To elucidate possible signaling pathways induced by integrin ,3,1, we looked for proteins that interact with the cytoplasmic part of the ,3A integrin subunit. We identified several multifunctional proteins by affinity chromatography and subsequent MALDI-TOF-MS and focused on the inhibitor 1 of serine/threonine phosphatase PP2A (I1PP2A, synonym: lanp) which also plays a role during the development of the mouse cerebellum. I1PP2A/lanp colocalizes with the ,3A integrin subunit in differentiated PC12 cells in the cell body and in neurites as well as in Purkinje cells of mouse cerebellum. Overexpression of GFP-I1PP2A/lanp in PC12 cells leads to markedly reduced neurite length on laminin 5 after induction with nerve growth factor. By affinity chromatography the protein phosphatase PP1 can also be identified as a ,3A/cyto-binding protein. PP1 and integrin ,3,1 can be pulled down by GST-I1PP2A/lanp from cell lysates of differentiated and undifferentiated PC12 cells. The phosphatase binds to the cytoplasmic membrane-proximal conserved GFFKR motif of the , integrin subunit, whereas I1PP2A/lanp requires a longer sequence for binding. PP1 but not PP2A is able to dephosphorylate precipitated integrin ,3,1 in vitro. Furthermore, PP1 releases phosphate from T1046 of phosphopeptides that mimic the phosphorylation consensus sequence in the cytoplasmic part of the ,3A integrin subunit. These data suggest that I1PP2A/lanp forms a complex with PP1 and the ,3A integrin subunit and might possibly regulate the phosphorylation status of integrin ,3,1 and/or integrin downstream targets. © 2006 Wiley-Liss, Inc. [source] Temporal responses in the disruption of iron regulation by manganeseJOURNAL OF NEUROSCIENCE RESEARCH, Issue 8 2006Catherine Kwik-Uribe Abstract Manganese (Mn) is an essential trace element, though at elevated exposures it is also a neurotoxicant. Several mechanisms underlying manganese toxicity have been investigated, although a consistent mechanism(s) of action at low exposures has not been fully elucidated. Here we systematically evaluated the effects of in vitro manganese exposure on intracellular iron (Fe) homeostasis and iron-regulatory protein (IRP) binding activity in undifferentiated PC12 cells over a range of manganese exposure concentrations (1, 10, 50, and 200 ,M MnCl2) and exposure durations (12, 24, 36, and 48 hr), to test the hypothesis that moderately elevated manganese exposure disrupts cellular iron regulation. Results demonstrate that manganese exposure produces a rapid and sustained dose-dependent dysregulation of cellular iron metabolism, with effects occurring as early as 12 hr exposure and at manganese doses as low as 1 ,M. Manganese exposure altered the dynamics of IRP-1 binding and the intracellular abundance of IRP-2, and altered the cellular abundance of transferrin receptor, ferritin, and mitochondrial aconitase protein levels. Cellular levels of labile iron were significantly increased with manganese exposure, although total cellular iron levels were not. The overall pattern of effects shows that manganese produced an inappropriate cellular response akin to iron deficiency, to which the cells were able to mount a compensatory response. Consistent with our previous studies, these data indicate that even low to moderate exposures to Manganese in vitro significantly disrupt cellular iron metabolism, which may be an important contributory mechanism of manganese neurotoxicity. © 2006 Wiley-Liss, Inc. [source] EXPRESSION OF P2X PURINOCEPTORS IN PC12 PHAEOCHROMOCYTOMA CELLSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2007Ji-Hu Sun SUMMARY 1The PC12 cell line, which was cloned from a rat adrenal phaeochromocytoma, is a useful model system. It expresses neuronal properties after treatment with nerve growth factor (NGF). The nervous system-specific P2X receptor subtype P2X2 was initially cloned from PC12 cells, but little is known about the expression of other subtypes of P2X receptors in PC12 cells. The aim of the present study was to investigate whether PC12 cells express the other P2X receptors when exposed to NGF. 2Reverse transcription,polymerase chain reaction at the mRNA level and immunocytochemisty at the protein level showed that, among the seven P2X purinoceptor subtypes, only P2X2 was found to be expressed in undifferentiated PC12 phaeochromocytoma cells, but all seven P2X purinoceptor subtypes were expressed in differentiated PC12 cells treated with 50 µg/mL NGF. 3Electrophysiological recordings indicated that ATP (30 µmol/L) but not ,,,-methylene ATP (,,,-meATP; 30 µmol/L) evoked an inward current in undifferentiated PC12 cells, but both ,,,-meATP and ATP evoked inward currents in differentiated PC12 cells. The results indicate that the NGF-induced P2X receptors expressed in PC12 cells are functional channels. 4The present study suggests that the NGF-induced neuronal phenotype of PC12 cells may be a model for the study of P2X heteromeric receptors. 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