In order to balance the cellular requirements for copper with its toxic properties, an elegant set of mechanisms has evolved to regulate and buffer intracellular copper. The X-linked inhibitor of apoptosis (XIAP) prot...
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In order to balance the cellular requirements for copper with its toxic properties, an elegant set of mechanisms has evolved to regulate and buffer intracellular copper. The X-linked inhibitor of apoptosis (XIAP) protein was recently identified as a copper-binding protein and regulator of copper homeostasis, although the mechanism by which XIAP binds copper in the cytosol is unclear. Here we describe the identification of the copper chaperone for superoxide dismutase (CCS) as a mediator of copper delivery to XIAP in cells. We also find that CCS is a target of the E3 ubiquitin ligase activity of XIAP, although interestingly, ubiquitination of CCS by XIAP was found to lead to enhancement of its chaperone activity toward its physiologic target, superoxide dismutase 1, rather than proteasomal degradation. Collectively, our results reveal novel links among apoptosis, copper metabolism, and redox regulation through the XIAP-CCS complex.
Abstract Abstract 4926 CD30 is a member of the tumor necrosis factor (TNF) receptor family that is normally found on the cell surface of a small subset of activated lymphocytes but is overexpressed on the surface of a...
Abstract Abstract 4926 CD30 is a member of the tumor necrosis factor (TNF) receptor family that is normally found on the cell surface of a small subset of activated lymphocytes but is overexpressed on the surface of anaplastic large cell lymphoma (ALCL) and Hodgkins lymphoma (HL) cells. Although many drugs exist that treat lymphomas by triggering the intrinsic cell death pathway, current chemotherapeutic regimens are limited by unwanted side effects, including secondary malignancies that limit event-free survival. The tumor-restricted overexpression of CD30 makes it an attractive target for therapeutic intervention. Depending on the cellular context, CD30 stimulation has been linked to cell death, cell cycle arrest, or paradoxically, proliferation. In ALCL tumor cell lines, CD30 stimulation activates both the canonical and noncanonical NF-kB pathways while in HL tumor cell lines, CD30 stimulation only slightly enhances NF-kB activity above constitutive levels, implying a role for NF-kB in determining the sensitivity or resistance of lymphoma cells to CD30-induced apoptosis. In addition, IAP antagonists, small synthetic compounds that mimic the structure of the second mitochondrial activator of caspase (Smac) and target IAP molecules that affect the activation of the non-canonical NF-kB pathway, induce apoptosis and/or sensitize cells to death via secondary signals such as TNF. This suggests that the modulation of IAP levels, and consequently regulation of the non-canonical NF-kB pathways, may also have a role in determining tumor cell death. Using representative ALCL and HL tumor cell lines, we have found that CD30 stimulation via its physiologically ligand in combination with standard chemotherapeutic agents results in increased efficacy in tumor cell death in the majority of ALCL cell lines but not HL cell lines. Similarly, IAP antagonists in combination with standard chemotherapeutic agents also resulted in enhanced tumor cell death in most ALCL but not HL cell l
In the shape memory alloys (SMAs) the thermal triggering induces reversible dimensional change by the phase transformation - these materials may also be ferri- or ferromagnetic, however, here only the ferromagnetic SM...
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ISBN:
(纸本)9783908158257
In the shape memory alloys (SMAs) the thermal triggering induces reversible dimensional change by the phase transformation - these materials may also be ferri- or ferromagnetic, however, here only the ferromagnetic SMAs are discussed. In certain SMAs the austenite-martensite phase transformation is influenced by the magnetic field as either austenite or martensite is promoted by the field and this is exploited for the dimensional changes. However, in the magnetic shape memory (MSM) alloys no phase transformation occurs as the remarkable dimensional changes take place by the twin variant changes in the martensitic phase activated by the external magnetic field at constant temperature. In addition to the phase transformation or magnetic shape memory effect, the applied magnetic field may also result in the conventional magneto strict ion (MS), enhance the superelasticity (magnetic-Field-assisted superelasticity MFAS) or induce the giant magnetocaloric effect (GMCE). Certain alloys such as Ni-Mn-Ga may even be multifunctional showing more than one of these effects. The present paper gives an overview of the different types of the magnetically activated SMA alloys, their properties as well as their potentials for applications in the frameworks of the recent studies.
By investigating the nitrogen concentrations in effluents of the horizontal subsurface-flow constructed wetlands under the conditions of different kinds of substrates, residence time and heights, as well as the nitrog...
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ISBN:
(纸本)9781424491728
By investigating the nitrogen concentrations in effluents of the horizontal subsurface-flow constructed wetlands under the conditions of different kinds of substrates, residence time and heights, as well as the nitrogen concentrations changes along the flow in the wetlands, the nitrogen removal routes in the wetlands were analyzed. The results demonstrated that the wetland system with zeolites demonstrated greater efficiency in the removal of nitrogen. There was a higher nitrogen removal rates at the bottom of the wetland system owing to an aerobic-anoxic environment. In that a more efficient reoxygenation was attained at the front of the system, it achieved a higher nitrogen removal rates.
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