<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Corallini, Federica</style></author><author><style face="normal" font="default" size="100%">Celeghini, Claudio</style></author><author><style face="normal" font="default" size="100%">Rimondi, Erika</style></author><author><style face="normal" font="default" size="100%">di Iasio, Maria Grazia</style></author><author><style face="normal" font="default" size="100%">Gonelli, Arianna</style></author><author><style face="normal" font="default" size="100%">Secchiero, Paola</style></author><author><style face="normal" font="default" size="100%">Zauli, Giorgio</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Trail down-regulates the release of osteoprotegerin (OPG) by primary stromal cells.</style></title><secondary-title><style face="normal" font="default" size="100%">J Cell Physiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Cell. Physiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bone Marrow Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Death</style></keyword><keyword><style  face="normal" font="default" size="100%">Cells, Cultured</style></keyword><keyword><style  face="normal" font="default" size="100%">Coculture Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Down-Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Endothelial Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">Enzyme Activation</style></keyword><keyword><style  face="normal" font="default" size="100%">Enzyme-Linked Immunosorbent Assay</style></keyword><keyword><style  face="normal" font="default" size="100%">Fibroblasts</style></keyword><keyword><style  face="normal" font="default" size="100%">Humans</style></keyword><keyword><style  face="normal" font="default" size="100%">MAP Kinase Signaling System</style></keyword><keyword><style  face="normal" font="default" size="100%">Mesenchymal Stromal Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">Osteoprotegerin</style></keyword><keyword><style  face="normal" font="default" size="100%">p38 Mitogen-Activated Protein Kinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Protein Binding</style></keyword><keyword><style  face="normal" font="default" size="100%">Recombinant Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Stromal Cells</style></keyword><keyword><style  face="normal" font="default" size="100%">TNF-Related Apoptosis-Inducing Ligand</style></keyword><keyword><style  face="normal" font="default" size="100%">Tumor Necrosis Factor-alpha</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Sep</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">226</style></volume><pages><style face="normal" font="default" size="100%">2279-86</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;The soluble member of the TNF-R superfamily osteoprotegerin (OPG) is abundantly released under basal conditions by both mesenchymal stem cells (MSC) and fibroblasts and by endothelial cells upon stimulation with inflammatory cytokines. Since MSC, fibroblasts and endothelial cells represent key elements of the normal and tumor microenvironment and express detectable levels of surface TRAIL receptors, we investigated the effect of TRAIL on OPG release. Unexpectedly, recombinant TRAIL decreased the spontaneous OPG release in all cell types examined. Moreover, TRAIL decreased OPG release also in stromal cells co-cultured with lymphoma cells and counteracted the OPG induction by TN-alpha in HUVEC and MSC. Such down-regulation was not due to a masking effect in the ELISA quantification of the OPG released in the culture supernatants due to binding of OPG to its ligands (TRAIL and RANKL), as demonstrated by competition experiments with recombinant TRAIL and by the lack of RANKL release/induction. In addition, OPG down-regulation was not due to induction of cytotoxic effects by TRAIL, since the degree of apoptosis in response to TRAIL was negligible in all primary cell types. With regards to the possible molecular mechanism accounting for the down-regulation of OPG release by TRAIL, we found that treatment of MSC with TRAIL significantly decreased the phosphorylation levels of p38/MAPK. There is a suggestion that this pathway is involved in the stabilization of OPG mRNA. In this respect, the ability of TRAIL to decrease the release of OPG, in the absence of cell cytotoxicity, was mimicked by the p38/MAPK inhibitor SB203580.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21660951?dopt=Abstract</style></custom1></record></records></xml>