We review recent evidence from lesion, pharmacological
and electrophysiological studies to support the view that a primary function of septohippocampal acetylcholine is to reduce interference in the learning process by adaptively timing and separating encoding and retrieval processes. We reinterpret cholinergic-lesion based deficits according to this view and propose that acetylcholine reduces the interference elicited Selleck ARS-1620 by the movement of salient locations between events. (C) 2012 Elsevier Ltd. All rights reserved.”
“Disulfides are conventionally viewed as structurally stabilizing elements in proteins but emerging evidence suggests two disulfide subproteomes exist. One group mediates the well known role of structural stabilization. A second redox-active group are best known for their catalytic functions but are increasingly being recognized for their roles in regulation of protein function. Redox-active disulfides are, by their very nature, more susceptible to reduction than structural disulfides; and conversely, the Cys pairs that form them are more susceptible to oxidation. In this study, we searched for potentially redox-active Cys Pairs by scanning
the Protein Data Bank for structures of proteins in alternate redox states. The PDB contains over 1134 unique redox pairs of proteins, many of which exhibit conformational Quisinostat manufacturer differences between alternate redox states. Several classes of structural changes were observed, proteins that exhibit: disulfide oxidation following expulsion of metals such as zinc; major reorganisation of the polypeptide backbone in association DNA ligase with disulfide redox-activity; order/disorder transitions; and changes in quaternary structure. Based on evidence gathered supporting disulfide redox activity, we propose disulfides present in alternate redox states are likely to have physiologically relevant redox activity.”
“Triptolide, isolated from the herb Tripterygium wilfordii, has been shown to potently induce apoptosis in various malignant cells by inhibiting RNA synthesis and nuclear
factor-kappa B activity. Previously, we showed that triptolide promotes apoptosis in acute myeloid leukemia (AML) cells via the mitochondria-mediated pathway, in part, by decreasing levels of the antiapoptotic proteins XIAP and Mcl-1. MRx102 is a triptolide derivative, currently in preclinical development. Here we show that MRx102 potently promoted apoptosis in AML cell lines, with EC50 values of 14.5+/-0.6 nM and 37.0+/-0.9 nM at 48 h for OCI-AML3 and MV4-11 cells, respectively. MRx102, at low nanomolar concentrations, also induced apoptosis in bulk, CD34(+) progenitor, and more importantly, CD34(+)CD38(-) stem/progenitor cells from AML patients, even when they were protected by coculture with bone marrow derived mesenchymal stromal cells. MRx102 decreased XIAP and Mcl-1 protein levels and inhibited RNA synthesis in OCI-AML3 cells.